IEEE Transactions on Industrial Electronics 

Volume 47,  Number 1, Feb. 2000           Access to the journal on IEEE XPLORE     IE Transactions Home Page

 

Power Electronics

1. 1.     B.W. Williams, S.J. Finney, "Passive snubber energy recovery for a GTO thyristor inverter bridge leg," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 2-8, Feb. 2000.  Full Text Link
Abstract : This paper presents a turn-on and turn-off passive energy recovery snubber circuit suitable for high-voltage high-power gate-turn-off thyristor inverter bridge configurations. The circuit recovers not only inductive turn-on and capacitive turn-off snubber energies, but also energies associated with freewheel diode reverse recovery. Energy is transferred back to the DC supply via a high-frequency transformer, that is fully reset. A method for reducing the transformer secondary diode voltage stress is presented. The performance of the circuit is supported by PSpice simulation, mathematical analysis, and practical results

1. 2.     K. Sheng, S.J. Finney, B.W. Williams, "Thermal stability of IGBT high-frequency operation," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 9-16, Feb. 2000.  Full Text Link
Abstract : Thermal stability of high-frequency insulated gate bipolar transistor (IGBT) operation is studied in this paper. The nonpunch-through IGBT is found to be stable when operated within its rated temperature. Thermal runaway occurs with punch-through IGBTs at temperatures below the maximum junction temperature when operated at high frequency at well below rated current, with snubber or soft-switching circuits

1. 3.     S. Carabelli, F. Maddaleno, M. Muzzarelli, "High-efficiency linear power amplifier for active magnetic bearings ," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 17-24, Feb. 2000.  Full Text Link
Abstract : A modified class-G linear amplifier has been developed to improve the overall efficiency of a transconductance amplifier loaded with the high inductance and low resistance typical of the magnetic bearing coils. A simple theoretical characterization has been used to provide some diagrams to optimize the power efficiency as a function of a nonconstant load such as that due to a rotor unbalance. Experimental results are reported that show a more than satisfactory agreement with the expected results and the developed theory

1. 4.     Ching-Tsai Pan, Jenn-Jong Shieh, "New space-vector control strategies for three-phase step-up/down AC/DC converter," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 25-35, Feb. 2000.  Full Text Link
Abstract : In this paper, an equivalent DC duty cycle for the generalized zero-voltage space vectors is proposed such that control of the three-phase AC part and the DC part of the converter circuit can be integrated to achieve the ideal characteristic of single-stage step-up/down AC/DC converter. Depending upon how many modes are chosen and which class of generalized zero-voltage space vectors is selected to increase the equivalent DC duty cycle, different control strategies can be obtained. It is seen that not only the control of the six switches is simplified but also the deadtime circuit for avoiding short circuit of the same arm can be eliminated for the proposed converter. In addition, some guidelines for selecting the LC parameters are described briefly and experimental results given for verifying the validity of the proposed converter

1. 5.     Yim-Shu Lee, K.C. Wong, C.K. Ng, "Behavior modeling of magnetizing currents in switch-mode DC-DC converters," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 36-44, Feb. 2000.  Full Text Link
Abstract : This paper describes a new technique to model the behavior of the magnetizing current in a transformer-coupled switch-mode DC-DC converter. The new technique uses a virtual magnetizing winding, together with a virtual magnetizing current source, to account for the effect of the magnetizing inductance on the switching operation of the transformer. By including the effect of the magnetizing current, the behavior model of a switch-mode converter can be made more complete. The model developed is particularly useful for the analysis and low-frequency behavior simulation of complex converters such as actively-clamped converters, where the magnetizing current significantly affects the characteristics of the converter

1. 6.     B.K.H. Wong, H. Shu-Hung Chung, "A systematic graphing technique for small-signal low-frequency characterization of PWM DC/DC converters," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 45-54, Feb. 2000.  Full Text Link
Abstract : This paper presents a systematic graphing technique for the small-signal low-frequency characterization of pulsewidth-modulated (PWM) DC/DC power converters. The methodology starts with using a discrete-time state-space description to formulate a small-signal sensitivity graph for each circuit topology. Each graph correlates state-variable sensitivities with the topology duration, input source and state vector at the beginning of the topology. The overall converter sensitivities in one switching cycle are obtained by cascading the respective graphs in accordance with the sequence of the topologies. As the proposed method integrates with original algorithms for obtaining the time-domain responses and the steady-state operating point of converters, it is unnecessary to have a priori understanding of the converter operation and is possible to obtain actual circuit waveforms within one switching cycle. The proposed method is exemplified by analyzing a PWM boost converter operating in continuous conduction mode and discontinuous conduction mode under open-loop and closed-loop control, respectively. Theoretical predictions are verified with experimental measurements

1. 7.     Yie-Tone Chen, "Small-signal analysis of a synchronous-switch post regulator with coupled inductors," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 55-66, Feb. 2000.  Full Text Link
Abstract : A small-signal model of the synchronous-switch post regulator with coupled inductors is developed. Performance variations of the synchronous switch post regulator due to different coupling coefficients are investigated. Comparison of the multiple-output converter using the technique of post regulation with the multiple-output converter using the scheme of weighted-mode control is also discussed. Experiments are given to verify the validity of the proposed small-signal model

1. 8.     J.H. Chen, K.T. Chau, C.C. Chan, "Analysis of chaos in current-mode-controlled DC drive systems," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 67-76, Feb. 2000.  Full Text Link
Abstract : In this paper, chaotic behavior in current-mode-controlled dc drive systems has been analyzed. The key is to derive an iterative map that describes the nonlinear system dynamics. Analytical modeling of fundamental and subharmonic oscillations as well as their stability analysis are presented. The results show that current-mode-controlled DC motor drive systems generally exhibit chaotic behavior. To avoid the occurrence of chaos, the stable ranges of various system parameters are determined. Both computer simulation and experimental measurement are given to verify the theoretical analysis
 

Drive Control



1.9.     L. Harnefors, H.-P. Nee, "A general algorithm for speed and position estimation of AC motors ," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 77-83, Feb. 2000.  Full Text Link
Abstract : A computationally efficient speed and position estimation algorithm, generally applicable to AC motor drives, is designed and analyzed. Applications include: (a) sensorless permanent-magnet and reluctance synchronous motor drives using the fundamental excitation as information source; (b) sensorless drives using saliency and signal injection; and (c) sensored drives using resolvers. Particular attention is given for case (a). Low parameter sensitivity in the entire speed range (except at low speeds for the reluctance motor)-implying a small position estimation error-and good dynamic properties at nominal speeds are verified

1. 10.     T. Emura, Lei Wang, "A high-resolution interpolator for incremental encoders based on the quadrature PLL method," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 84-90, Feb. 2000.  Full Text Link
Abstract : This paper presents a new high-resolution interpolator for incremental encoders based on the quadrature phase-locked loop method proposed by Emura. Until now, this method has been applied to controllers of high-precision servomechanisms and has shown excellent performance. In this paper, the authors apply the method for the first time to an interpolator for incremental encoders. The experimental results show that high-speed interpolation is possible, with a maximum output frequency of 25 MHz-20 times higher than that of conventional interpolators. The interpolator proposed was also tested for noise rejection with a high-speed numerically controlled gear grinding machine, and has shown good noise rejection capability. This paper presents the design of the interpolator and the experimental results

1. 11.     Jun-Koo Kang, Seung-Ki Sul, "Vertical-vibration control of elevator using estimated car acceleration feedback compensation," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 91-99, Feb. 2000.  Full Text Link
Abstract : In this paper, a vibration suppression strategy is proposed for improving the riding comfort of an elevator, using car acceleration feedback compensation. The vertical vibration of a lift car is mainly caused by the resonance of elastic ropes between the car and the sheave, and the resonant frequency of the system is dependent upon both passenger load and lift position. To suppress the vibration of a lift car, the car velocity or acceleration is needed, but only a sheave velocity is measurable in a practical situation. The proposed method applies an extended full-order observer for the simultaneous estimation of car acceleration and the identification of mechanical parameters. Acceleration feedback compensation is used for the vibration suppression control. Experimental evaluation has been performed with a 30 kVA insulated gate bipolar transistor inverter and a medium-speed elevator system in an elevator test tower. Computer simulated and experimental results prove the feasibility of the proposed vertical-vibration controller

1. 12.     S.C. Mukhopadhyay, T. Ohji, M. Iwahara, S. Yamada, "Modeling and control of a new horizontal-shaft hybrid-type magnetic bearing," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 100-108, Feb. 2000.  Full Text Link
Abstract : This paper reports on the development of a new horizontal-shaft hybrid-type magnetic bearing system. The bearing system will be used for a horizontal-shaft machine. The rotor is levitated due to the repulsive force between a stator and a rotor permanent magnet (PM). A lower cost and higher radial stiffness have been achieved by using a strontium-ferrite magnet on the rotor and an Nd-Fe-B PM above and below the rotor magnet. A finite-element analysis was performed to calculate the levitation force and radial stiffness. An upper stator magnet subtending an angle of 45° provides the best compromise between a large levitation force and radial stiffness. A model for the horizontal-shaft hybrid magnetic bearing system has been developed and includes the effect of the rotor dynamics and the electromagnetic forces. An integral servocontroller was designed to stabilize the axial position. The controller has been implemented in a digital signal processor. Experimental results performed on a prototype system are in agreement with the theoretical results

1. 13.     Sung Jun Park, Han Woong Park, Man Hyung Lee, F. Harashima, "A new approach for minimum-torque-ripple maximum-efficiency control of BLDC motor," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 109-114, Feb. 2000.  Full Text Link
Abstract : Torque-ripple control of the brushless DC motor has been the main issue of the servo drive systems in which the speed fluctuation, vibration, and acoustic noise should be minimized. Most methods for suppressing the torque ripples require Fourier series analysis and either iterative or least-mean-square minimization. In this paper, a novel approach to achieve ripple-free torque control with maximum efficiency based on the d-q-0 reference frame is presented. The proposed method optimizes the reference phase current waveforms which include the case of three-phase unbalanced conditions. As a result, the proposed approach provides a simple way to obtain optimal motor excitation currents. The validity and practical applications of the proposed control scheme are verified through the simulations and experimental results

1. 14.     C. Mademlis, J. Xypteras, N. Margaris, "Loss minimization in surface permanent-magnet synchronous motor drives," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 115-122, Feb. 2000.  Full Text Link
Abstract : The loss minimization in surface permanent-magnet synchronous motor drives is investigated. Based on theoretical analysis, a loss model controller is introduced to specify the optimal air-gap flux that minimizes losses. Theoretical results are verified experimentally. The proposed loss model controller is simple and does not adversely affect the cost and complexity of the drive. Implementation of the loss model controller does not require knowledge of the loss model. The suggested loss minimization method can be applied both in V/f- or current-controlled schemes

1. 15.     G.D. Marques, P. Verdelho, "A simple slip-power recovery system with a DC voltage intermediate circuit and reduced harmonics on the mains," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 123-132, Feb. 2000.  Full Text Link
Abstract : A different circuit configuration for the slip-power recovery system is presented in this paper. A boost chopper is used to connect the diode rectifier to the DC-link voltage, which is composed of a capacitor and a voltage-source inverter (VSI). The diode rectifier gives rise to mains current harmonies of variable frequency, which can present subharmonics, harmonics, and interharmonics that can lead to flicker in the mains. Two simple solutions to this drawback are studied. In the first solution, additional inductances were connected on the AC side of the rotor circuits to increase the overlap angle. In the second solution, the stator current harmonics are compensated by a VSI that can work simultaneously as an inverter and as an active power filter. This system represents a very interesting and useful application for active power filters. The merits of the configuration presented are cost, control simplicity, the possibility of reactive power control over a wide range, and quasi-optimum exploitation of the electrical machine. The characteristics of the proposed system and its control are presented in this paper. It is concluded that, although the system proposed is much simpler than others, it has interesting performance
 

Robotics and Vision



1.16.     Jae Wook Jeon, Young Youl Ha, "A generalized approach for the acceleration and deceleration of industrial robots and CNC machine tools," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 133-139, Feb. 2000.  Full Text Link
Abstract : Many techniques for the acceleration and deceleration of industrial robots and computer numerical control (CNC) machine tools have been proposed in order to make industrial robots and CNC machine tools perform given tasks efficiently. Although the techniques selecting polynomial functions can generate various acceleration and deceleration characteristics, the major problem is the computational load. The digital convolution techniques are more efficient than the techniques selecting polynomial functions. However, neither velocity profiles of which the deceleration characteristics is independent from the acceleration characteristics nor those of which the acceleration interval is different from the deceleration interval can be generated by the digital convolution techniques. This paper proposes a generalized approach for generating velocity profiles that cannot be generated by the digital convolution techniques. According to the desired characteristics of acceleration and deceleration, each set of coefficients is calculated and is stored. Given a moving distance, and acceleration and deceleration intervals, a velocity profile having the desired characteristics of acceleration and deceleration can be efficiently generated by using these coefficients. Several velocity profiles generated by the proposed technique are applied to one single-axis control system

1. 17.     A. Piazzi, A. Visioli, "Global minimum-jerk trajectory planning of robot manipulators," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 140-149, Feb. 2000.  Full Text Link
Abstract : A new approach based on interval analysis is developed to find the global minimum-jerk (MJ) trajectory of a robot manipulator within a joint space scheme using cubic splines. MJ trajectories are desirable for their similarity to human joint movements and for their amenability to path tracking and to limit robot vibrations. This makes them attractive choices for robotic applications, in spite of the fact that the manipulator dynamics are not taken into account. Cubic splines are used in a framework that assures overall continuity of velocities and accelerations in the robot movement. The resulting MJ trajectory planning is shown to be a global constrained minimax optimization problem. This is solved by a newly devised algorithm based on interval analysis and proof of convergence with certainty to an arbitrarily good global solution is provided. The proposed planning method is applied to an example regarding a six-joint manipulator and comparisons with an alternative MJ planner are exposed

1. 18.     W.L. Xu, J.D. Han, S.K. Tso, Y.C. Wang, "Contact transition control via joint acceleration feedback," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 150-158, Feb. 2000.  Full Text Link
Abstract : Stable and controllable transition from free motion to constrained motion is of central importance for robots in contact with the environment in many applications. In this paper, a joint acceleration feedback control scheme of high bandwidth is employed to damp oscillations during the contact transition when the approaching speed does not vanish. In this control scheme, a classical integral force controller is refined by means of joint acceleration and velocity feedback. This is intended to achieve a stable contact transition without need of adjusting the controller parameters adaptive to the unknown or changing environments. Extensive experiments are conducted on the third joint of a three-link direct-drive robot to verify the proposed scheme for the environments of various stiffnesses, including elastic (sponge), less-elastic (cardboard), and hard (steel plate) surfaces. Results are also compared with those by the transition control without the acceleration feedback. The proposed scheme is shown to be promising in terms of robustness, stability and adaptability

1. 19.     R. Zunino, S. Rovetta, "Vector quantization for license-plate location and image coding," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 159-167, Feb. 2000.  Full Text Link
Abstract : License-plate location in sensor images plays an important role in vehicle identification for automated transport systems (ATS). This paper presents a novel method based on vector quantization (VQ) to process vehicle images. The proposed method makes it possible to perform superior picture compression for archival purposes and to support effective location at the same time. As compared with classical approaches, VQ encoding can give some hints about the contents of image regions; such additional information can be exploited to boost location performance. The VQ system can be trained by way of examples; this gives the advantages of adaptiveness and on-field tuning. The approach has been tested in a real industrial application and included satisfactorily in a complete ATS for vehicle identification
 

Signal Processing



1.20.     A.R. Pauchard, D. Manic, A. Flanagan, P.A. Besse, R.S. Popovic, "A method for spark rejection in ultraviolet flame detectors," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 168-174, Feb. 2000.  Full Text Link
Abstract : A novel method is presented to render ultraviolet (UV) flame detectors insensitive to ignition spark radiation. The method involves isolating the signal due to the sparks from the UV sensor output and subtracting a DC signal proportional to it from the output of the flame detector sensor system. A practical demonstration of the method is given using a commercially available UV flame detector with the addition of an analog circuit to perform the necessary signal processing. A selectivity improvement to spark radiation of greater than 130 has been obtained. The method is robust in that it is independent of the distance between the light source and the flame detector and has been designed to work with different spark generators found on the market. The analog circuit is simple, requiring few components, thus ensuring rugged, fail-safe operation and low cost

1. 21.     Weng Khuen Ho, Tong Heng Lee, Wen Xu, J.R. Zhou, Ee Beng Tay, "The direct Nyquist array design of PID controllers," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 175-185, Feb. 2000.  Full Text Link
Abstract : The gain and phase margins design for single-input single-output proportional-integral-derivative controllers is extended to the multivariable system's Nyquist array. The design method allows the user to specify the robustness and performance of the system through gain and phase margin specifications. The unformatted design procedure given in this paper is well suited for implementing self-tuning PID control for multivariable processes. A laboratory implementation is given in the paper to demonstrate the design method

1. 22.     I. Nancovska, A. Jeglic, D. Fefer, L. Todorovski, "Deterministic predictive models for DC voltage reference source control," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 186-192, Feb. 2000.  Full Text Link
Abstract : In this paper, we use predictive models for voltage correction in a high-precision DC voltage reference source (DCVRS) based on Zener diodes. Voltage reference elements, which compose the DCVRS, are improved by implementing a control loop with built-in predictors. Thus, the sensitivity of the system is reduced and, thereby, the stability of the DCVRS is improved. The predictive abilities of two different paradigms, neural-network-based predictors and difference equation predictors obtained by equation discovery system LAGRAMGE, are compared

1. 23.     Wen Fang Xie, A.B. Rad, "Fuzzy adaptive internal model control," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 193-202, Feb. 2000.  Full Text Link
Abstract : In this paper, a fuzzy adaptive internal model controller (FAIMC) for open-loop stable plants is presented. The control scheme consists of two parts: a fuzzy dynamic model and a model-based fuzzy controller. A fuzzy dynamic model, which serves as the internal model of the FAIMC is identified online by using the input and output measurement of the plant. Based on the identified fuzzy model, the fuzzy controller is designed to minimize an H2 performance objective. This FAIMC scheme has been successfully applied to control the flow rate in a laboratory-scale process control unit from Bytronic. The experimental results demonstrate that this class of control scheme is appropriate for control of time-varying stable plants with time delay. The control system is also shown to possess satisfactory robust performance

1. 24.     K.M. Tsang, W.L. Lo, A.B. Rad, "Autotuning of phase-lead controller for integrating systems," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 203-210, Feb. 2000.  Full Text Link
Abstract : In this paper, a new method for autotuning of a phase-lead controller for nonselfregulating or integrating systems is proposed. By connecting the system with a suitable high-order derivative filter and a relay with hysteresis, the frequency data of the system can be obtained and phase-lead controllers can be designed based on some phase margin specifications. Simulations and experimental studies are included in the paper to illustrate the performance of the proposed algorithm
 

Emerging Technologies



1.25.     S. Obayashi, T. Tsukahara, T. Nakamura, "Multiobjective genetic algorithm applied to aerodynamic design of cascade airfoils," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 211-216, Feb. 2000.  Full Text Link
Abstract : A multiobjective genetic algorithm (GA) based on Fonseca-Fleming's Pareto-based ranking and fitness-sharing techniques has been applied to aerodynamic shape optimization of cascade airfoil design. Airfoil performance is evaluated by a Navier-Stokes code. Evaluation of GA population is parallelized on the Numerical Wind Tunnel, a parallel vector machine. The present multiobjective design seeks high pressure rise, high flow turning angle, and low total pressure loss at a low Mach number. Pareto solutions that perform better than existing control diffusion airfoils were obtained
 

Letters to the Editor



1.26.     W.G. da Silva, P.P. Acarnley, J.W. Finch, "Application of genetic algorithms to the online tuning of electric drive speed controllers," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 217-219, Feb. 2000.  Full Text Link
Abstract : Tuning of electric drive speed controllers is complicated by nonlinearities. Usual practice obtains controller settings with conventional linear analysis methods and then tunes the settings using trial-and-error methods during commissioning. An alternative approach, using genetic algorithms for the online tuning, is proved experimentally to optimize the drive's response efficiently. These settings are critically dependent on operating point

1. 27.     P.B. Boyagoda, M. Nakaoka, "An advanced tracking controller with neural networks for servo systems," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 219-222, Feb. 2000.  Full Text Link
Abstract : A novel controller for generic servo systems using a neural network input-output measurement classifier and a staggered proportional plus integral plus derivative-like gain control scheme is proposed. The controller incorporates a knowledge-based control strategy and does not require a priori knowledge of the plant. The system controller is robust to both structured and unstructured uncertainties

1. 28.     S. Ben-Yaakov, S. Glozman, R. Rabinovici, "Envelope simulation by SPICE-compatible models of electric circuits driven by modulated signals," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 222-225, Feb. 2000.  Full Text Link
Abstract : SPICE-compatible equivalent circuits were developed to facilitate the analysis and envelope simulation of electric circuits driven by modulated signals. The circuits are based on a novel complex phasor domain transformation. The proposed method facilitates fast simulation of any general linear circuit driven by a modulated signal, such as amplitude, frequency, or phase modulation

1. 29.     Sin-Yeung Cho, T.W.S. Chow, "Shape and surface measurement technology by an improved shape-from-shading neural algorithm," Trans. on Industrial Electronics, vol. 47, no. 1, pp. 225-230, Feb. 2000.  Full Text Link
Abstract : A new approach for measuring the shape and surface of an object observed from a single camera is proposed. The proposed approach is based on using the neural networks as a parametric representation of the three-dimensional object and the shape-from-shading problem is formulated as the minimization of an intensity error function with respect to the network weights. Experimental results demonstrate that the authors' proposed methodology exhibits high efficiency and accuracy for measuring and inspecting a product's surface in the manufacturing industry

 

Volume 47,  Number 2, Apr. 2000           Access to the journal on IEEE XPLORE     IE Transactions Home Page


 

Power Electronics



2. 1.     H.S.-H. Chung, S.Y.R. Hui, S.C. Tang, A. Wu, "On the use of current control scheme for switched-capacitor DC/DC converters," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 238-244, Apr. 2000.  Full Text Link
Abstract : This paper presents an investigation into the use of a current control scheme (CCS) and a comparison with a classical switching scheme for switched-capacitor (SC) step-down DC/DC converters. With the CCS, capacitors are charged with near-constant current, controlled by the gate-source voltage of MOSFETs. By paralleling two SC cells, the converter input current becomes continuous, resulting in much reduced conducted electromagnetic interference with other circuits fed by the same power supply. All MOSFETs are operated for half of the switching period, in order to improve the regulation capability. Static and dynamic behaviors of the converter with the CCS are predicted and confirmed in an experimental 36 W 12 V/9 V prototype

2. 2.     Bor-Ren Lin, Hsin-Hung Lu, "A novel PWM scheme for single-phase three-level power-factor-correction circuit," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 245-252, Apr. 2000.  Full Text Link
Abstract : This paper presents a control scheme for a single-phase AC-to-DC power converter with three-level pulsewidth modulation. A single-phase power-factor-correction circuit is proposed to improve the power quality. The hysteresis current control technique for a diode bridge, with two power switches is adopted to achieve a high power factor and low harmonic distortion. A control scheme is presented where the line current is driven to follow the reference sinusoidal current which is derived from the DC-link voltage regulator, the capacitor voltage balance compensator and the output power estimator. The blocking voltage of each power device is clamped to half of the DC-link voltage. The high power factor and low current total harmonic distortion are verified by computer simulations and hardware tests

2. 3.     K.K. Tse, H.S.-H. Chung, S.Y.R. Hui, H.C. So, "A comparative investigation on the use of random modulation schemes for DC/DC converters," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 253-263, Apr. 2000.  Full Text Link
Abstract : A comparative investigation on the use of random modulation schemes for DC/DC power converters is presented. The modulation schemes under consideration include randomized pulse position modulation, randomized pulsewidth modulation (PWM) and randomized carrier-frequency modulation with fixed and variable duty cycle. The paper emphasizes the suitability and applicability of each scheme in DC/DC power converters. Issues addressed include the effectiveness of randomness level on spreading the dominating frequencies that normally exist in constant-frequency PWM schemes, and the low-frequency power spectral density (PSD) of each scheme. The validity of the analyses is confirmed experimentally by using a DC/DC buck converter operating in the continuous conduction mode. The PSD of the output under each scheme is presented and compared

2. 4.     V.M. Pacheco, A.J. do Nascimento, V.J. Farias, J. Batista Vieira, L.C. de Freitas, "A quadratic buck converter with lossless commutation," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 264-272, Apr. 2000.  Full Text Link
Abstract : High switching frequency associated with soft commutation techniques is a new trend in switching converters. Following this trend, the authors present a buck pulsewidth modulation converter, where the DC voltage conversion ratio has a quadratic dependence on duty cycle, providing a large step-down. By introducing two resonant networks, soft switching is attained, providing highly efficient operating conditions for a wide load range at high switching frequency. Contrary to most of the converters that apply soft-switching techniques, the switches presented are not subjected to high switch voltage or current stresses and, consequently, present low conduction losses. The authors present, for this converter, the principle of operation, theoretical analysis, relevant equations and simulation and experimental results

2. 5.     Tsai-Fu Wu, Yu-Kai Chen, Yong-Heh Huang, "3C strategy for inverters in parallel operation achieving an equal current distribution," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 273-281, Apr. 2000.  Full Text Link
Abstract : A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper. In the proposed inverter system, all the modules have the same circuit configuration, and each module includes an inner current loop and an outer voltage loop control. A proportional-integral controller is adopted as the inner current loop controller to expedite the dynamic response, while an H∞ robust controller is adopted to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters. With the 3C strategy, the modules are in circular chain connection and each module has an inner current loop control to track the inductor current of its previous module, achieving an equal current distribution. Simulation results of two-module and a three-module inverter systems with different kinds of loads and with modular discrepancy have demonstrated the feasibility of the proposed control scheme. Hardware measurements are also presented to verify the theoretical discussion

2. 6.     A.L. Shenkman, B. Axelrod, V. Chudnovsky, "A new simplified model of the dynamics of the current-fed parallel resonant inverter," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 282-286, Apr. 2000.  Full Text Link
Abstract : In this paper, the transient analysis of a current-fed parallel inverter, widely used in industrial applications (such as for the heating and melting of metals), is performed. A high-inductance smoothing inductor is usually connected in the input of the inverter and its load may be represented by a parallel resonant circuit characterized by high quality factor Q. To simplify the dynamic analysis of such an inverter, approximating it by a second-order switchless continuous dynamic link (i.e., RLC circuit) is suggested. The comparative analysis of the inverter and approximating circuit, whose parameters are properly chosen, shows the permissibility of such an approximation. It also shows how to assure desired aperiodic dynamic behavior. Then, by analyzing the approximating circuit, the expressions for inverter parameters are found. With these expressions, the values of a smoothing inductor, a compensating capacitance and a voltage factor, in order to ensure the aperiodic behavior of the inverter, can be calculated. The results of the proposed analysis were checked on laboratory and industrial prototypes of the above inverter. The theoretical and experimental results are in good agreement

2. 7.     Tsai-Fu Wu, Chien-Hsuan Chang, Yu-Hai Chen, "A fuzzy-logic-controlled single-stage converter for PV-powered lighting system applications," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 287-296, Apr. 2000.  Full Text Link
Abstract : This paper presents a fuzzy-logic-controlled single-stage power converter (SSC) for photovoltaic (PV)-powered lighting system applications. The SSC is the integration of a bidirectional buck-boost charger/discharger and a class-D series resonant parallel loaded inverter. The designed fuzzy logic controller (FLC) can control both the charging and discharging current, and can improve its dynamic and steady-state performance. Furthermore, a maximum power point tracker (MPPT) based on a perturb-and-observe method is also realized to effectively draw power from PV arrays. Both the FLC and the MPPT are implemented on a single-chip microprocessor. Simulated and experimental results obtained from the proposed circuit with an FLC have verified the adaptivity, robustness and feasibility

2. 8.     W. le Roux, J.D. van Wyk, "The effect of signal measurement and processing delay on the compensation of harmonics by PWM converters," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 297-304, Apr. 2000.  Full Text Link
Abstract : The effect of the delay time on the reference signal for compensation due to the data acquisition and digital signal processing is examined. The time delay will cause incorrect compensation and unwanted remaining nonactive power after compensation. A theoretical evaluation is done on the negative effect on compensation due to a single frequency distortion. This evaluation is expanded to handle multiple harmonic distortion to calculate the total theoretical ineffectivity of compensation for a specific load due to a specific time delay. This provides a method of calculating the ineffectivity caused by any delay in compensation, whatever the cause. Finally, the theoretical evaluations are validated by means of experimental results
 

Drive Control



2.9.     Duwang Li, R. Tymerski, T. Ninomiya, "Chebyshev series integration method for transient simulation of switched networks," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 305-314, Apr. 2000.  Full Text Link
Abstract : An efficient integration routine based on the Chebyshev series expansion is given. Adoption of a Chebyshev expansion minimizes the order of the polynomial approximation which together with a number of basic properties of the expansion results in an efficient integration method. Furthermore, integration error control may conveniently be approached by monitoring the coefficients of the expansion. The proposed error control scheme varies the expansion order while keeping the step size fixed. A software program for the simulation of networks with ideal switches was written which incorporates the above features. Two examples, one of a nonswitched network and the other of a switched network, are given to illustrate the speed and accuracy of the program and effectiveness of the error control scheme. To quantify the advantages of the proposed scheme, a comparison is made with a previously developed simulator (viz., LAPS) and also a commercially available SPICE program

2. 10.     H.Z. Akpolat, G.M. Asher, J.C. Clare, "A practical approach to the design of robust speed controllers for machine drives," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 315-324, Apr. 2000.  Full Text Link
Abstract : This paper presents a practical approach to the robust speed control of electrical drives. The approach is based on sliding mode control (SMC), but it is shown how sampling time, system noise, actuation limit, and antiwindup integrator reduce the control to an online maximum-gain selection constrained by system noise. The paper proposes a trajectory-reference compensator and fuzzy gain interpolator to fully exploit the system actuation while avoiding chattering and remaining within specified noise limits, only the SMC switching line needs to be selected; the remaining control design is systematic and, thus, should be of interest to drive engineers in industry. Experimental results on a vector-controlled AC motor drive rig with variable-inertia loads are presented to verify the approach

2. 11.     S.R. Bowes, Jian Li, "New robust adaptive control algorithm for high-performance AC drives," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 325-336, Apr. 2000.  Full Text Link
Abstract : This paper presents a new robust structure for a model reference adaptive control (MRAC) controller for field-oriented-controlled (FOC) drives which requires no prior knowledge of the drive parameters and is guaranteed to provide global asymptotic stability of the closed-loop system. This structure simplifies the design and implementation of the adaptive controller requiring less effort to synthesis than a standard MRAC system. Discussion on theoretical aspects, such as selection of a reference model, stability analysis proof, gain adaptive process, steady-state error elimination, and robustness to unmodeled dynamics are included. The paper describes many practical aspects of the implementation, such as adaptive gain analysis, adaptive rate selection, the gain variation limits, gain windup prevention measure, and initial values. The new robust adaptive controller has been successfully implemented on an FOC drive and experiment results for dynamic tracking, sudden loading and unloading, and gains adaptation under different operation conditions are presented to support the robustness of the proposed controller

2. 12.     J. Hirai, Tae-Woong Kim, A. Kawamura, "Position-sensorless drive of linear pulse motor for suppressing transient vibration," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 337-345, Apr. 2000.  Full Text Link
Abstract : The linear pulse motor (LPM) has been widely used because of its simple structure and easy control without the use of feedback. However, degradation of the response performance occurs, resulting from the transient vibration which is inherent in the LPM. The fastest way to suppress the vibration is to close the control loop using the position feedback sensor, However, the straightforward use of such a sensor feedback leads to higher cost and complicated configuration, sacrificing the structural advantage of the LPM. Therefore, the authors propose a Kalman filter-based sensorless control for suppressing the transient vibration. In this proposed control method, the LPM mover position and speed are optimally estimated using an extended Kalman filter applied to the nonlinear state equations of excitation winding circuits. The effectiveness of this method is confirmed by experiments on a prototype LPM control system using a digital signal processor

2. 13.     Guchuan Zhu, L.-A. Dessaint, O. Akhrif, A. Kaddouri, "Speed tracking control of a permanent-magnet synchronous motor with state and load torque observer," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 346-355, Apr. 2000.  Full Text Link
Abstract : This paper is concerned with the speed tracking control problem for a permanent-magnet synchronous motor (PMSM) in the presence of an unknown load torque disturbance. After a brief review of the mathematical model of the PMSM, a speed tracking control law using the exact linearization methodology is introduced. The tracking control algorithm is completed by adding an extended observer which provides, on the one hand, the motor speed and acceleration and, on the other hand, estimates the unknown load torque. The stability of the closed-loop system composed of a nonlinear speed tracking controller and an observer is studied by the way of Lyapunov theory. Furthermore, the decoupling of the state observer and the load torque observer is discussed. Finally, a real-time implementation and the experimental results of the proposed control strategy are presented

2. 14.     Faa-Jeng Lin, Rong-Jong Wai, Chih-Hong Lin, Da-Chung Liu, "Decoupled stator-flux-oriented induction motor drive with fuzzy neural network uncertainty observer," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 356-367, Apr. 2000.  Full Text Link
Abstract : A stator-flux-oriented induction motor drive using online rotor time-constant estimation with a robust speed controller is introduced in this paper. The estimation of the rotor time constant is made on the basis of the model reference adaptive system using an energy function. The estimated rotor time-constant is used in the current-decoupled controller, which is designed to decouple the torque and flux in the stator-flux-field-oriented control. Moreover, a robust speed controller, which is comprised of an integral-proportional speed controller and a fuzzy neural network uncertainty observer, is designed to increase the robustness of the speed control loop. The effectiveness of the proposed control scheme is demonstrated by simulation and experimental results

2. 15.     K.R. Thompson, P.P. Acarnley, C. French, "Rotor position estimation in a switched reluctance drive using recursive least squares," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 368-379, Apr. 2000.  Full Text Link
Abstract : This paper describes a new algorithm for the estimation of rotor position in a switched reluctance motor. It is based on a recursive least-squares estimator deducing both position and speed. A particular advantage of the algorithm is its ability to extract information about rotor position at very low speeds (one electrical cycle per minute) from voltage and current waveforms sampled only at the converter switching frequency. Experimental results for a 12/8 motor demonstrate that estimation is possible over the full range of operating conditions, including the field-weakening region, with a typical accuracy of better than two mechanical degrees. The paper also illustrates the performance of the algorithm by showing it operating within a sensorless position controller

2. 16.     B. Robyns, F. Berthereau, J.-P. Hautier, H. Buyse, "A fuzzy-logic-based multimodel field orientation in an indirect FOC of an induction motor," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 380-388, Apr. 2000.  Full Text Link
Abstract : Classical indirect field-oriented control is highly sensitive to uncertainties in the rotor resistance of the induction motor. This sensitivity can be reduced by combining two different methods to compute the stator electrical frequency. Fuzzy logic is used to combine both methods to obtain a compromise which reduces the flux control sensitivity to electrical parameter errors at each operating point. The design of the fuzzy logic block is based on a theoretical sensitivity analysis taking magnetic saturation into account, in simulations and in experiments. In this paper, the performance of the proposed control algorithm is theoretically and experimentally studied. The theoretical predictions are validated by experiments, by considering the stator current variations, to develop a given steady-state torque, induced by the imperfect flux control
 

Robotics and Vision



2.17.     N. Kasa, H. Watanabe, "A mechanical sensorless control system for salient-pole brushless DC motor with autocalibration of estimated position angles," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 389-395, Apr. 2000.  Full Text Link
Abstract : In this paper, a mechanical sensorless control system is reported for salient-pole brushless DC motor drives. Here, two new methods are proposed for obtaining the position angle, the accuracy of which affects the operation of the switching devices of the inverter that drives the motor. First, the method for estimating the position angle is proposed. Secondly, the correcting method for reducing the errors involved in the estimation of position angle is given. The experimental results show that the estimated position angles are calibrated automatically, and then the proposed sensorless control system can control the speed and the position angles of the motor precisely

2. 18.     M. Kaufhold, H. Aninger, M. Berth, J. Speck, M. Eberhardt, "Electrical stress and failure mechanism of the winding insulation in PWM-inverter-fed low-voltage induction motors," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 396-402, Apr. 2000.  Full Text Link
Abstract : The winding insulation of low-voltage induction motors in adjustable-speed drive systems with voltage-fed inverters is substantially more stressed than in line-powered motors. Consequently, this operation is subject to limitations depending on the electrical stress and on the failure behavior of the winding insulation. Actual recommendations do not consider sufficiently the physics behind these phenomena and contain large utilizable reserves

2. 19.     Seul Jung, T.C. Hsia, "Robust neural force control scheme under uncertainties in robot dynamics and unknown environment," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 403-412, Apr. 2000.  Full Text Link
Abstract : The original impedance function is known to lack robustness due to unknown robot dynamic model and the environment. In order to improve that result, a new impedance function is derived which specifies a desired force directly. This results in a new robust robot force tracking impedance control scheme, which employs a neural network as a compensator to cancel out all uncertainties. The proposed neural force control scheme is capable of making the robot track a specified desired force as well as of compensating for uncertainties in environment location and stiffness, and in robot dynamics. Separate training signals for free-space motion and contact-space motion control are developed to train the neural compensator online. The design of the training signals is justified. Simulation studies with a three-link rotary robot manipulator are carried out and the results show excellent force tracking performance
 

Signal Processing



2.20.     S. Komada, N. Machii, T. Hori, "Control of redundant manipulators considering order of disturbance observer," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 413-420, Apr. 2000.  Full Text Link
Abstract : A manipulator control method using a disturbance observer with no inverse dynamics has been proposed. The order of the disturbance observer affects the performance of control system, because nominalization of plant is dependent on the control object and the order of the disturbance observer. This paper proposes a unique choice of disturbance observers of different order in joint and task space to improve system performance of hybrid position/force control of redundant manipulators. Also, it has been shown that a proper selection of a coefficient of the disturbance observer is capable to improve robust stability, while not influencing basic performance. The proposed strategy can realize acceleration control and second derivative of force control in the task space, which realizes robust and precise control of manipulators. Experimental results using a redundant manipulator show the effectiveness of the proposed strategy

2. 21.     Shiuh-Jer Huang, Ji-Shin Lee, "A stable self-organizing fuzzy controller for robotic motion control," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 421-428, Apr. 2000.  Full Text Link
Abstract : It is well known that robotic manipulators are highly nonlinear coupling dynamic systems. It is difficult to establish an appropriate mathematical model for the design of a model-based controller. Although fuzzy logic control has a model-free feature, it still needs time-consuming work for the rules bank and fuzzy parameters adjustment. In this paper, a stable self-organizing fuzzy controller (SOFC) is proposed to manipulate the motion trajectory of a 5-degrees-of-freedom robot. This approach has a learning ability for responding to the time-varying characteristic of a robot. Its control rules bank can be established and modified continuously by online learning with zero initial fuzzy rules. In addition, this control strategy has effectively improved the stability problem of a previous SOFC. The experimental results show that this intelligent controller has a stable learning ability and good motion control capability

2. 22.     Xinkai Chen, S. Komada, T. Fukuda, "Design of a nonlinear disturbance observer," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 429-437, Apr. 2000.  Full Text Link
Abstract : This paper presents a new disturbance observer based on the variable structure system theory for minimum-phase (with respect to the relationship between the disturbance and output) dynamical systems with arbitrary relative degrees. The model uncertainties and the nonlinear parts of the system are merged into the disturbance term and are regarded as a part of the disturbances. The upper and lower bounds of the disturbance are assumed to be known as a priori information. Simulation results are presented to show the robustness and effectiveness of the new disturbance observer. Experimental results show the practicality of the new observer
 

Emerging Technologies



2.23.     D. Cole, S. Sridharan, M. Moody, "Frequency offset correction for HF radio speech reception," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 438-443, Apr. 2000.  Full Text Link
Abstract : High-frequency single-sideband (HF-SSB) radio communication suffers from highly variable propagation conditions and high levels of interference noise. One common distortion is frequency shifting of the received signal due to differences in carrier frequencies at transmitter and receiver, or to Doppler shifts due to the transmission path. This paper presents a novel and efficient technique to compensate for this frequency offset using only the received speech signal to determine and correct the frequency error. Good improvement in received speech quality is achieved, using a mean opinion score measurement

2. 24.     Kuo-Kai Shyu, Cheng-Yuan Chang, "Modified FIR filter with phase compensation technique to feedforward active noise controller design," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 444-453, Apr. 2000.  Full Text Link
Abstract : In this paper, a finite-impulse response (FIR) filter with phase compensation is proposed to design the digital controller for active noise cancellation in ducts. This method can overcome the influence of delay effects, which arise from the analog devices, and then help to improve the ability of noise reduction. Moreover, all the control algorithms are implemented in a fixed-point-type digital signal processor that produces an antinoise signal to cancel noise in the authors' experiments. Experiments are demonstrated in a polyvinyl chloride material circular duct. It is proved that, by using the FIR filter with phase compensation, the reduction of broadband noise is about 20 dB, and about 50 dB of narrowband noise. The system also provides the ability to cancel the noise with two harmonic components, like automobile noise

2. 25.     W.L. Xu, S.K. Tso, Y. Tso, "Reuse of existing design information in the development of new electronic PTC devices via a neural network approach," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 454-469, Apr. 2000.  Full Text Link
Abstract : Burning events and voltage endurance are two important aspects that need to be predicted during the design and development stage of a new series of electronic positive temperature coefficient (PTC) devices. In this paper, these problems are identified by experiments conducted on well-developed devices, and are resolved by improving the resistance-temperature characteristics of the PTC devices in order to overdamp, underdamp, or critically damp high-current/high-voltage surges. The use of neural networks is proposed, to learn the empirical or experimental design information that already exists, and then to predict the occurrence of burning events and the voltage endurance of new PTC devices at the design/development stage. Two predictive schemes are presented separately, for burning events and for voltage endurance, where the training patterns for the desired outputs are either generated from empirical formulae or collected from experiments on already-developed PTC devices. The predicted results are discussed against the experimental results that are available, and an overall concept is finally given for the integration of the neural predictive models into the computer-aided design/computer-aided engineering system used for the PTC devices

2. 26.     M.H.R. Fazlur Rahman, R. Devanathan, Zhu Kuanyi, "Neural network approach for linearizing control of nonlinear process plants," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 470-477, Apr. 2000.  Full Text Link
Abstract : The application of a feedback linearization technique using artificial neural networks (ANNs) for a nonlinear industrial process plant is considered in this paper. The process plant is modeled first using an ANN, and then the dynamic neural network model acting as a process plant emulator is feedback linearized. A novel configuration for linearization of an ANN emulator using only backpropagation is used. Effective control of the linearized emulator is then exhibited using a linear controller. Experimentation and simulation results on the linearized emulator are presented to demonstrate the effectiveness of the feedback linearization technique

2. 27.     T.W.S. Chow, Xiao-Dong Li, Yong Fang, "A real-time learning control approach for nonlinear continuous-time system using recurrent neural networks," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 478-486, Apr. 2000.  Full Text Link
Abstract : In this paper, a real-time iterative learning control (ILC) approach for a nonlinear continuous-time system using recurrent neural networks (RNNs) with time-varying weights is presented. Two RNNs are utilized in the ILC system. One is used to approximate the nonlinear system and another is used to mimic the desired system response. The ILC rule is obtained by combining the two RNNs to form a neural network control system. Also, a kind of iterative RNNs training algorithm is developed based on the two-dimensional (2-D) system theory. An RNN using the proposed 2-D training algorithm is able to approximate any trajectory to a very high degree of accuracy. Simulation results show that the proposed ILC approach is very efficient. The newly developed 2-D RNNs training algorithms provides a new dimension to the application of RNNs in a nonlinear continuous-time system

2. 28.     M. Onder Efe, O. Kaynak, B.M. Wilamowski, "Stable training of computationally intelligent systems by using variable structure systems technique," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 487-496, Apr. 2000.  Full Text Link
Abstract : This paper presents a novel training algorithm for computationally intelligent architectures, whose outputs are differentiable with respect to the adjustable design parameters. The algorithm combines the gradient descent technique with the variable-structure-systems approach. The combination is performed by expressing the conventional weight update rule in continuous time and application of sliding-mode control method to the gradient-based training procedure. The proposed combination therefore exhibits a degree of robustness with respect to the unmodeled multivariable internal dynamics of gradient descent and to the environmental disturbances. With conventional training procedures, the excitation of this dynamics during a training cycle can lead to instability, which may be difficult to alleviate due to the multidimensionality of the solution space and the ambiguities on the free design parameters, such as learning rate or momentum coefficient. This paper develops a heuristic that a computationally intelligent system, which may be a neural network architecture or a fuzzy inference mechanism, can be trained such that the adjustable parameter values are forced to settle down (parameter stabilization) while minimizing an appropriate cost function (cost optimization). The proposed approach is applied to the control of a robotic arm in two different ways. In one, a standard fuzzy system architecture is used, whereas in the second, the arm is controlled by the use of a multilayer perceptron. In order to demonstrate the robustness of the approach presented, a considerable amount of observation noise and varying payload conditions are also studied

Letters to the Editor



2. 29.     P. Pejovic, Z. Janda, "An improved current injection network for three-phase high-power-factor rectifiers that apply the third harmonic current injection," Trans. on Industrial Electronics, vol. 47, no. 2, pp. 497-499, Apr. 2000.  Full Text Link
Abstract : A novel current injection network for low-harmonic rectifiers that apply the third harmonic current injection is proposed in this paper. The current injection network requires one inductor, two capacitors, and one 1:1 transformer with a voltampere rating of only 0.16% of the input power. The transformer is introduced to provide complete rejection of harmonic components of the injected currents at even triples of the line frequency, resulting in significant reduction of the input current total harmonic distortion (THD). Dependence of the input current THD on the current injection network Q factor is computed. The THD is shown to be in the range 4%<THD<5.125%. Analytically obtained results are experimentally verified on a 1.5 kW rectifier

 

Volume 47,  Number 3, Jun. 2000           Access to the journal on IEEE XPLORE     IE Transactions Home Page

 

Power Electronics

3. 1.     S. Buso, G. Spiazzi, "A line-frequency-commutated rectifier complying with IEC 1000-3-2 standard," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 501-510, Jun. 2000.  Full Text Link
Abstract : Consumer and household appliances require low-cost AC/DC power supplies complying with EMC standards. The commonly employed passive solutions are bulky and do not provide output voltage stabilization. Active solutions, based on power-factor correctors with high-frequency switching, provide compactness and regulation capability, but are generally expensive due to the need for fast-recovery diodes and complex EMI filters. This paper presents a high-power-factor rectifier, based on a modified conventional rectifier with passive L-C filter, which improves both the harmonic content of the input current and the power factor by means of a low-frequency-commutated switch and a small line-frequency transformer, and allows compliance with IEC 1000-3-2 standard with reduced overall inductive components' volume

3. 2.     S.R. Shaw, C.R. Laughman, S.B. Leeb, R.F. Lepard, "A power quality prediction system," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 511-517, Jun. 2000.  Full Text Link
Abstract : This paper describes two hardware prototypes and estimation schemes for determining the parameters of a simple, physically based, point-of-use electric utility model using transient measurements. Parameters of the utility model are estimated using data collected by the prototypes. Frequency-dependent effects observed in previous work in this area are modeled. Performance of the techniques given is demonstrated by comparison of measured and predicted line voltage distortion during current transients created by several loads

3. 3.     H. Benqassmi, J.-C. Crebier, J.-P. Ferrieux, "Comparison between current-driven resonant converters used for single-stage isolated power-factor correction," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 518-524, Jun. 2000.  Full Text Link
Abstract : The aim of this paper is to analyze the power factor correction capability of isolated current-source resonant converter topologies with two energy storage elements, which takes advantage of the leakage inductance of the HF transformer. These converter topologies are studied and modeled. Computer simulation results are also given. Thanks to its interesting characteristics, a converter topology is chosen and a converter prototype is built in order to validate theoretical study. Using this converter topology, a very good power factor is achieved

3. 4.     H.D. Laird, S.D. Round, R.M. Duke, "A frequency-domain analytical model of an uncontrolled single-phase voltage-source rectifier," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 525-532, Jun. 2000.  Full Text Link
Abstract : The harmonic currents generated by the single-phase rectifier are well known. As the levels of these currents become larger, the use of power conditioners, such as shunt active filters, to lower the levels is becoming more attractive. In order to analyze the interaction between the condition, AC system and rectifier, it is necessary to have an accurate model of the rectifier. This paper describes a frequency-domain analytical model of the single-phase rectifier. The model includes the dominant frequency transfer mechanisms. These are the direct transfer and that due to the modulation of the switching instants. A small-signal linearized analysis is presented and the behavior predicted is confirmed by perturbation analysis using time-domain simulation. Accurate results are obtained, and the importance of including the switching instant modulation is shown

3. 5.     Z. Wang, Y. Liu, "Modeling and simulation of a cycloconverter drive system for harmonic studies," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 533-541, Jun. 2000.  Full Text Link
Abstract : This paper discusses the steady-state harmonic modeling and simulation of a cycloconverter drive system (CDS). The operation and control of a cycloconverter drive and a synchronous motor load were modeled in the time domain. Based on the duality principle of electric and magnetic circuits, four types of three-phase transformer models with detailed nonlinear magnetizing characteristics were implemented. The harmonic behaviors of the entire system were studied under several worst operation conditions. The goal of this paper is to understand the harmonic problems associated with a CDS from an integrated system point of view, with special attention given to harmonic filtering and cancellation effect of converter coupling transformers

3. 6.     K. Chatterjee, B.G. Fernandes, G.K. Dubey, "A novel high-power low-distortion synchronous link converter-based load compensator without the requirement of VAr calculator," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 542-548, Jun. 2000.  Full Text Link
Abstract : A high-power low-distortion static VAr compensator based on a synchronous link converter has been proposed, where the harmonics are eliminated by incorporating a low-power insulated-gate-bipolar-transistor-based controlled current auxiliary converter in conjunction with a high-power gate-turn-off-thyristor-based converter. In this paper, a new load compensator based on this topology is proposed which does not require the information of the voltampere required by the load. As the requirement of the reactive voltampere calculator is eliminated, the scheme becomes insensitive to system frequency variations, temperature, and component aging. The control scheme required for the compensator is developed. The operation of the scheme is validated through extensive simulation studies. Experimental results obtained from a laboratory prototype are provided to demonstrate the viability of the scheme

3. 7.     A.C.S. De Lima, H.W. Dommel, R.M. Stephan, "Modeling adjustable-speed drives with long feeders," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 549-556, Jun. 2000.  Full Text Link
Abstract : This paper presents the modeling of different topologies of electric drive systems when the cable that connects the converter to the motor has a significant length. The long feeder together with converter harmonics decrease the performance of the motor. To correctly assess the voltage and the current throughout the drive system, frequency-dependent models for the cable and the motor should be used. A frequency-dependent cable model is necessary for an accurate voltage evaluation while a frequency-dependent motor model responds for accuracy in the current. The models were validated through experimental results carried out on an actual oil platform and from a prototype system. The latter system was used to test the system's performance when very long motor leads (longer than 5 km) are involved

3. 8.     Nambo Hur, Kwanghee Nam, Sangchul Won, "A two-degrees-of-freedom current control scheme for deadtime compensation," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 557-564, Jun. 2000.  Full Text Link
Abstract : A current controller having an inverse dynamic model and a proportional-integral (PI) controller has been proposed with the aim of compensating the effects of deadtime. The proposed control scheme, having two degrees of freedom, can be used for compensating the effects of disturbance without degrading tracking performance. To be specific, the disturbance-rejection property is enhanced by increasing the gains of the PI controller, but the PI gain does not affect the transfer function between the current command and its output. By nature, it is robust to the parameter mismatch error between the model and the plant, since the mismatch error can be counted as another disturbance. With the experimental results, we have shown the superiority of the proposed method in suppressing the current distortion caused by deadtime

3. 9.     A.H. Anbuky, P.E. Pascoe, "VRLA battery state-of-charge estimation in telecommunication power systems," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 565-573, Jun. 2000.  Full Text Link
Abstract : This paper presents the logical analysis of valve-regulated lead-acid battery discharge behavior and suggests a model for obtaining estimates of the state of charge (SOC) and reserve time throughout discharge. The basis of the model is the relationship between the discharge voltage and SOC. This relationship is valid for a wide range of discharge rates and ambient temperatures as related to the telecommunications backup power supply application. Due to the robust nature of this relationship, only a single discharge characteristic under nominal operating conditions is required by the model. Case studies reveal that the model enables accuracy in estimation of SOC of better than 10% of actual SOC after discharging 10% of the rated capacity. As the discharge proceeds, the error reduces substantially. A feature of the model is that it is easily adaptable to changes in battery characteristics which occur as a result of extreme stress
Drive Control



3.bsp;   D. Munoz, D. Sbarbaro, "An adaptive sliding-mode controller for discrete nonlinear systems ," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 574-581, Jun. 2000.  Full Text Link
Abstract : This paper presents a sliding-mode controller for a class of nonlinear discrete-time systems. The proposed controller uses a modified switching function that produces a low-chattering control signal. In order to improve the controller performance, an adaptive term is added to the original sliding-mode algorithm. This new feature uses an artificial neural network for online identification of the modeling error. Simulations and experimental results illustrate the main characteristics and performance of this approach,

3. 11.     Z. Chen, M. Tomita, S. Doki, S. Okuma, "New adaptive sliding observers for position- and velocity-sensorless controls of brushless DC motors," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 582-591, Jun. 2000.  Full Text Link
Abstract : A new adaptive sliding observer is proposed for position- and velocity-sensorless controls of a cylindrical brushless DC motor. Stability of the proposed observer is guaranteed easily, because it is based on a linear model of the motor. Sliding mode is applied for the current estimation. Under the sliding mode, the order of the observer's error equation is reduced. This makes the stability analysis easier, so that robust position and velocity estimations might be achieved by the pole assignment. Experimental results show that the proposed method is very effective

3. 12.     G.-W. Chang, G. Espinosa-Perez, E. Mendes, R. Ortega, "Tuning rules for the PI gains of field-oriented controllers of induction motors," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 592-602, Jun. 2000.  Full Text Link
Abstract : The authors have previously shown that field-oriented controllers for induction motors preserve stability under a wide range of variations of the motor and controller parameters. However, as is well known, the transient performance critically depends on the tuning of the gains of the proportional-integral (PI) velocity loop, a task which is rendered difficult because of the high uncertainty on the rotor resistance. The problem we address in this paper is how to develop an offline procedure to choose these gains. The main contribution of our work is a very simple frequency-domain test that, for each setting of the PI gains, evaluates the maximum range of the relative rotor resistance estimate for which global stability is guaranteed. In this way, we provide a quantitative estimate of the performance of the PI controller. The stability result may also be used in a dual manner, fixing now the range of the rotor resistance, and estimating an admissible interval for the PI gains that preserves global stability. Instrumental for our study is the exploitation of an energy dissipation (strict passivity) property of the system

3. 13.     G. Zhang, "Speed control of two-inertia system by PI/PID control," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 603-609, Jun. 2000.  Full Text Link
Abstract : The purpose of this paper is to develop systematic analysis and design methods for a two-inertia system. A conventional proportional-integral speed control system with a torsional load is redesigned, and the damping characteristic of the system is derived and analyzed. It is shown that the dynamic characteristic of the system strongly depends on the inertia ratio of load to motor. Three kinds of typical pole assignments with identical radius/damping coefficient/real part are applied and compared, and the merits of each pole-assignment design are concluded. Furthermore, for small inertia ratio, we present how to improve the damping of the system by a derivative feedback of motor speed

3. 14.     F. Betin, D. Pinchon, G.-A. Capolino, "Fuzzy logic applied to speed control of a stepping motor drive," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 610-622, Jun. 2000.  Full Text Link
Abstract : Nowadays, thanks to the development of microprocessors, stepping motors are widely used in robotics and in the numerical control of machine tools where they have to perform high-precision positioning operations. Nevertheless, the variations of the mechanical configuration of the drive, which are common to these two applications, can lead to a loss of synchronism for high stepping rates. Moreover, the classical open-loop speed control is weak and a closed-loop control becomes necessary. In this paper, the fuzzy logic principle is applied to control the speed of a stepping motor drive with feedback. An advanced test bed is used in order to evaluate the tracking properties and the robustness capacities of the fuzzy logic controller when variations of the mechanical configuration occur. The experiment has been performed using a low-cost 16 bit microcontroller in order to verify the design performance

3. 15.     C.M. Bingham, D.A. Stone, N. Schofield, D. Howe, D. Peel, "Amplitude and frequency control of a vibratory pile driver," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 623-631, Jun. 2000.  Full Text Link
Abstract : This paper describes the digital control of a vibratory pile driver in which the vibration is generated via two tandem pairs of electrically driven, geared, contra-rotating eccentrics. Experimental results are included to show the controller-induced system dynamics for a variety of load conditions, and to highlight the fact that, if the relative phase of the eccentric pairs is not controlled, the natural tendency at high excitation frequency is for the pile driver to operate with a low vibration amplitude. An analytical technique for identifying the system parameters is presented, and analytical performance predictions are compared with experimental results. Analysis of the power flow in the system shows that, although significant power transfer occurs between the two electrical drives, the net power dissipation during pile driving is relatively low

3. 16.     O. Ojo, O. Omozusi, A.A. Jimoh, "The operation of an inverter-assisted single-phase induction generator," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 632-640, Jun. 2000.  Full Text Link
Abstract : The enhancement of the operability range of a stand-alone single-phase induction generator scheme with an inverter-battery system connected to the auxiliary winding is the theme of this paper. The reactive power requirement of the load connected to the main winding is met by the inverter system operating with either of two proposed pulsewidth modulation techniques, in the process of which the load voltage and frequency are regulated. The proposed schemes have potential application as power sources for autonomous systems and for utility interface to single-phase power system grids. Simulation and calculation results of the generator system connected to an impedance and motor loads, confirmed with some experimental results, are also set forth to validate some of the conclusions of the paper
 

Robotics and Vision



3.17.     K. Kiguchi, T. Fukuda, "Position/force control of robot manipulators for geometrically unknown objects using fuzzy neural networks," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 641-649, Jun. 2000.  Full Text Link
Abstract : In order to carry out the tasks of grinding, deburring, polishing or wiping, the end-effector of the robot manipulator has to follow the contour of an object. In this paper, the authors propose a fuzzy vector method, which enables the controller to deal efficiently with force sensor signals which include noise and/or unknown vibrations caused by the working tool, to search the direction of the constraint surface of an unknown object



Signal Processing
3. 19.     S.G. Tzafestas, E.J. Kyriannakis, "Regulation of GMA welding thermal characteristics via a hierarchical MIMO predictive control scheme assuring stability," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 668-678, Jun. 2000.  Full Text Link
Abstract : This paper deals with the regulation of the thermal characteristics of gas metal arc welding (GMAW). A complete treatment of the welding control problem requires the regulation of both the geometrical and thermal characteristics of the weld. Both classes of characteristics are of critical importance, but the thermal ones have received less attention in the majority of previous work. The present paper proposes a hierarchical predictive control scheme for the metallurgical characteristics of GMAW. A previously developed model for the regulation of the heat-affected zone, the cooling rate and the nugget cross-sectional area is used for the open-loop predictions. At the first level of the hierarchy, a parameterized generalized predictive control (GPC) algorithm is selected, among other control techniques, due to the inherited difficulty of the welding thermal process and the robustness of this algorithm against modeling errors and parameter variations. The main drawback of GPC is that it does not guarantee stability. The second level of the control hierarchy, where a coordinator specifies a set of reliable values for the parameters of GPC, so that stability is assured, and transmits them to the controller of the first level overcomes this difficulty. This paper provides a representative set of simulation results obtained by the present hierarchical GPC scheme, including a comparison with the classical linear-quadratic optimal control scheme. These results show the superiority of the GPC scheme

3. 20.     So-Young Jeong, Minho Lee, Soo-Young Lee, Jin-Man Cho, Cheol Hoon Park, "Improving lookup table control of a hot coil strip process with online retrainable RBF network," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 679-686, Jun. 2000.  Full Text Link
Abstract : This paper presents an online retrainable radial basis function (RBF) network to control the coiling temperature for a hot coil strip at the Pohang Iron and Steel Company, Pohang, Korea. The proposed RBF network is designed to replace the conventional rule-based lookup table, the output of which is a heat transmission coefficient in the temperature control system. In order to make the controller more adaptable to the changing environments in the steelmaking process, specific interconnection weights were additionally devised for the hidden-to-output weights of a conventional RBF network. These weights were locally adjustable to reduce the immediate temperature error of a coil strip, while the global information of the RBF network trained with offline past data was largely unaltered. As a result, the proposed RBF network substantially alleviated the effect of catastrophic interference-completely forgetting old information in the presence of new inputs. Moreover, a rejection network was incorporated within the proposed control scheme to ensure reliable operation in the actual process. Results applied to the real steelmaking process indicated an improvement of 2.2% in control performance compared to conventional methods

3. 21.     H.-Z. Tan, T.W.S. Chow, "Blind identification of quadratic nonlinear models using neural networks with higher order cumulants," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 687-696, Jun. 2000.  Full Text Link
Abstract : A novel approach to blindly estimate kernels of any discrete- and finite-extent quadratic models in higher order cumulants domain based on artificial neural networks is proposed in this paper. The input signal is assumed an unobservable independently identically, distributed random sequence which is viable for engineering practice. Because of the properties of the third-order cumulant functions, identifiability of the nonlinear model holds, even when the model output measurement is corrupted by a Gaussian random disturbance. The proposed approach enables a nonlinear relationship between model kernels and model output cumulants to be established by means of neural networks. The approximation ability of the neural network with the weights-decoupled extended Kalman filter training algorithm is then used to estimate the model parameters. Theoretical statements and simulation examples together with practical application to the train vibration signals modeling corroborate that the developed methodology is capable of providing a very promising way to identify truncated Volterra models blindly

Emerging Technologies



3. 22.     X. Li, A. Djordjevich, P.K. Venuvinod, "Current-sensor-based feed cutting force intelligent estimation and tool wear condition monitoring," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 697-702, Jun. 2000.  Full Text Link
Abstract : Tool wear condition monitoring has the potential to play a critical role in ensuring the dimensional accuracy of the workpiece and prevention of damage to cutting equipment. It could also help in automating cutting processes. In this paper, the feed cutting force estimated with the aid of an inexpensive current sensor installed on the AC servomotor of a computerized numerical control tuning center is used to monitor tool wear condition. To achieve this, the feed drive system is modeled, using neuro-fuzzy techniques, to provide the framework for estimating the feed cutting force based on the feed motor current measured. Functional dependence of the feed cutting force on tool wear and cutting parameters are then expressed in the form of a difference equation relating variation in the feed cutting force to tool wear rate. The computerized system automatically compares successive feed cutting force estimates and determines the onset of accelerated tool wear in order to issue a request for tool replacement. Experimental results show that the tool wear condition monitoring is effective and industrially applicable

3. 23.     Daijin Kim, "An implementation of fuzzy logic controller on the reconfigurable FPGA system," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 703-715, Jun. 2000.  Full Text Link
Abstract : This paper concerns an implementation of a fuzzy logic controller (FLC) on a reconfigurable field-programmable gate array (FPGA) system. In the proposed implementation method, the FLC is partitioned into many temporally independent functional modules, and each module is implemented individually on the FLC automatic design and implementation system, which is an integrated development environment for performing many subtasks such as automatic VHSIC hardware description language description, FPGA synthesis, optimization, placement and routing, and downloading. Each implemented module forms a downloadable hardware object that is ready to configure the FPGA chip. Then, the FPGA chip is consequently reconfigured with one module at a time by using the run-time reconfiguration method. This implementation method is effective when a single FPGA chip cannot fit the FLC due to the limited size of its constituent cells. We test the proposed implementation method by building the FLC for the truck backer-upper control on VCC Corporation's EVC-1 reconfigurable FPGA board directly
 

Letters to the Editor



3.24.     Jang-Hyoun Youm, Hyun-Lark Do, Bong-Hwan Kwon, "A single-stage electronic ballast with high power factor," Trans. on Industrial Electronics, vol. 47, no. 3, pp. 716-718, Jun. 2000.  Full Text Link
Abstract : A single stage electronic ballast with high power factor (HPF) is proposed in this letter. The single-phase boost-type rectifier provides HPF. A saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. Experimental results obtained on a 40 W fluorescent lamp are discussed

 

 

Volume 47,  Number 4, Aug. 2000           Access to the journal on IEEE XPLORE     IE Transactions Home Page

 

Power Electronics

4. 1.     P.J.M. Menegaz, J.L.F. Vieira, D.S.L. Simonetti, "A magnetically coupled regenerative turn-on and turn-off snubber configuration," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 722-728, Aug. 2000.  Full Text Link
Abstract : This paper presents a magnetically coupled regenerative turn-on and turn-off snubber configuration applied to a boost converter, which operates in continuous conduction mode (CCM). In addition to reducing the stresses in the switch, providing soft transitions in its turn-off voltage and turn-on current, it transfers the energy stored in the snubber capacitor to the load. This is achieved by using a coupled inductor mounted on the main inductor of the converter, which resets the capacitor voltage at each switching period. Design equations, as well as experimental results are presented, showing the high performance of the boost converter using the proposed snubber

4. 2.     A. Wolf, M. Thamodharan, "Reactive power reduction in three-phase electric arc furnace," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 729-733, Aug. 2000.  Full Text Link
Abstract : A conventional three-phase electric arc furnace causes flicker at the point of common coupling with AC mains. This generally occurs with AC mains having a low short-circuit capacity. The flicker is caused by flucluating reactive power consumption of the furnace. This paper describes a way, through computer simulation, of increasing the dynamic performance of the furnace and keeping reactive power consumption constant. This can be achieved with the addition of a three-phase power controller and a booster transformer to the power source and the introduction of a new control method of regulating the reactive power input. The problem of flicker can thus be minimized. This was experimentally tested on a single-phase model and the results obtained were very satisfying. Due to laboratory facilities, the three-phase testing was not performed

4. 3.     E.P. Wiechmann, R.P. Burgos, J. Holtz, "Sequential connection and phase control of a high-current rectifier optimized for copper electrowinning applications," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 734-743, Aug. 2000.  Full Text Link
Abstract : This paper proposes an optimized sequential control technique for copper electrowinning high-current rectifiers. The converter comprises two series-connected six-pulse double-wye rectifiers, a step-down transformer, and a tuned input filter. The six-pulse rectifiers are fed from delta and polygon primary windings with different turns ratio and phase shifted by 5°. Under the proposed control scheme, one rectifier is kept at nominal output voltage, and the other one is phase controlled to control the load's current. The proposed strategy greatly improves the rectifier's performance, reducing its reactive power maximum demand by 62% compared to conventional rectifiers and, therefore, reduces the input filters power rating also by 62%. This is accomplished while keeping the input power factor above 0.95 throughout the whole operating range. Further, the converter's reactive power consumption presents a low varying characteristic, allowing it to use a fixed filter, even when operating from a power system not capable of withstanding large reactive power variations. Finally, it presents a harmonic current distortion comparable to conventional 12-pulse high-current rectifiers. This paper presents the design and optimization procedure of the rectifying system. A 2.5 kVA laboratory prototype was used to validate the converter model, later employed in evaluating the converter operating in a 10.5 MVA copper electrowinning facility. The results obtained confirm the advantages of the proposed converter and its control strategy

4. 4.     Junyang Luo, Y.C. Liang, byung Jin Cho, "Design of LIGBT protection circuit for smart power integration," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 744-750, Aug. 2000.  Full Text Link
Abstract : Development of a monolithic power integrated circuit by making the lateral insulated gate bipolar transistor (IGBT) the main switching device is a current topic. The overcurrent protection scheme is usually necessary to be built as part of the function in such a power integrated circuit. The protection circuit requires distinguishing various fault conditions and reacting differently based on the device safe operating area (SOA) limitation. At the same time, the protection circuit should also be relatively concise and suitable for integration. In this paper, a concise circuit suitable for integration and with gate drive capability is proposed to provide the complete function of overcurrent SOA protection for the LIGBT. The operational principle was described in detail and the circuit performance was verified with experimental results from both the discrete circuit and the fabricated LIGBT integrated circuit

4. 5.     S.E. Lyshevski, "Resonant converters: nonlinear analysis and control," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 751-758, Aug. 2000.  Full Text Link
Abstract : The current trends in development and deployment of advanced switching converters have facilitated the unified activities in topology design, nonlinear analysis, optimization, and control. In this paper, by using nonlinear models of resonant converters, bounded controllers are designed to ensure a spectrum of performance objectives required. To attain high efficiency and power density, new converter topologies were developed. It is recognized that advanced closed-loop configurations must be designed to guarantee a spectrum of specifications and requirements imposed on the converter dynamics. The output voltage of converters is regulated by changing the duty ratio, which is constrained by lower and upper limits. In this paper, to approach design tradeoffs and analyze converter performance (settling time, overshoot, stability margins, and other quantities), the constraints and nonlinearities are thoroughly examined. Innovative controllers are synthesized to ensure performance improvements. To illustrate the control laws designed and to validate these algorithms, analytical and experimental results are presented and discussed. In particular, nonlinear analysis and design with experimental verification are performed and documented for a resonant converter with zero-current-switching

4. 6.     K.K. Tse, H. Shu-Hung Chung, S.Y.R. Hui, H.C. So, "Spectral characteristics of randomly switched PWM DC/DC converters operating in discontinuous conduction mode," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 759-769, Aug. 2000.  Full Text Link
Abstract : This paper addresses a comparative study of the spectral characteristics of four random-switching schemes that apply to the basic pulsewidth-modulation (PWM) DC/DC converters operating in discontinuous conduction mode (DCM). They include randomized pulse position modulation, randomized pulsewidth modulation, and randomized carrier frequency modulation with fixed duty cycle and with fixed duty time, respectively. Mathematical models that characterize the input current and output voltage of the three basic PWM converters operating in DCM are derived. In particular, the effectiveness of spreading the dominant switching harmonics in the input current that normally exist in the standard PWM scheme and the introduction of low-frequency harmonics in the output voltage with respect to the randomness level are investigated. The validity of the models and analyses are confirmed experimentally by using a DC/DC buck converter

4. 7.     Gang Chen, Yim-Shu Lee, S.Y.R. Hui, Dehong Xu, Yousheng Wang, "Actively clamped bidirectional flyback converter," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 770-779, Aug. 2000.  Full Text Link
Abstract : An actively clamped bidirectional flyback converter is proposed. The converter's operation is examined in detail. All switches in the converter have zero-voltage-switching characteristics. A low-frequency behavior model and small-signal transfer functions are derived. It is found that the flow of current is directly under the control of the duty cycle, and that the transformer's leakage inductance has a significant effect on the control characteristic of the converter. It is expected that such bidirectional converters will find wide applications in the interconnection of multiple sources of DC power to a common bus (e.g., in a DC uninterruptible power supply). Simulation and experiment results are also presented

4. 8.     Chang-Shiarn Lin, Chern-Lin Chen, "Single-wire current-share paralleling of current-mode-controlled DC power supplies," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 780-786, Aug. 2000.  Full Text Link
Abstract : This paper presents a new single-wire autonomous current-share paralleling of current-mode-controlled DC power supplies. The proposed control scheme makes use of the nature of fast response of the inner current loop and the share bus injected signal to improve the response of the power supplies. It reduces the unbalance of current distribution during the transient state and avoids the fault alarm for the current limit. Through the theoretical derivation, the proposed control circuit can be designed by the three-loop control method. A design example of two 400 V/48 V 20 A parallel modules is set up and experimental recordings verify the performance of current sharing

4. 9.     Po-Wa Lee, Yim-Shu Lee, D.K.W. Cheng, Xiu-Cheng Liu, "Steady-state analysis of an interleaved boost converter with coupled inductors," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 787-795, Aug. 2000.  Full Text Link
Abstract : Boost converters are widely used as power-factor corrected preregulators. In high-power applications, interleaved operation of two or more boost converters has been proposed to increase the output power and to reduce the output ripple. A major design criterion then is to ensure equal current sharing among the parallel converters. In this paper, a converter consisting of two interleaved and intercoupled boost converter cells is proposed and investigated. The boost converter cells have very good current sharing characteristics even in the presence of relatively large duty cycle mismatch. In addition, it can be designed to have small input current ripple and zero boost-rectifier reverse-recovery loss. The operating principle, steady-state analysis, and comparison with the conventional boost converter are presented. Simulation and experimental results are also given

4. 10.     C. Branas, F.J. Azcondo, S. Bracho, "Contributions to the design and control of LCsCp resonant inverters to drive high-power HPS lamps," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 796-808, Aug. 2000.  Full Text Link
Abstract : This paper presents the design criteria for full-bridge series-parallel (LCsCp) resonant inverters suitable for driving high-power high-intensity discharge lamps. By using the properties derived from the transfer functions of the inverter, a soft startup method is proposed. The lamp ignition is carried out maintaining the voltage and current variables below prefixed peak values, with the addition of no extra components to the power stage for this purpose. In steady-state operation, the proposed control minimizes the reactive voltamperes in the resonant tank. Moreover, the variation of the power delivered to the lamp, caused by the lamp aging, is limited in order to fulfil the standard. This design provides cost-effective circuits, simplifying the DC-AC power stage of an electronic ballast. The experimental results are given for high-pressure sodium lamps of the Sylvania SHP250W type

4. 11.     M.A. Co, D.S.I. Simonetti, J.L.F. Vieira, "High-power-factor electronic ballast based on a single power processing stage," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 809-820, Aug. 2000.  Full Text Link
Abstract : A new high-power-factor (HPF) electronic ballast is introduced in this paper. The proposed topology is based on a single power processing stage, and provides a high-frequency voltage to the fluorescent lamps in addition to presenting an HPF to the utility line. The power processing stage is formed by a half-bridge circuit operating above the resonant frequency, thus providing zero-voltage switching. The self-oscillating technique is employed, which increases the converter reliability with great simplicity. HPF is achieved by using a nonconventional boost stage operating in discontinuous conduction mode, which results in a lower DC-bus voltage than that produced by the conventional boost. Theoretical analysis and experimental results have been obtained for two 40-W fluorescent lamps operating at 40-kHz switching frequency and 220-V line voltage

4. 12.     Yie-Tone Chen, D.Y. Chen, "Small-signal modeling of magnetic amplifier post regulators with current-mode control," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 821-831, Aug. 2000.  Full Text Link
Abstract : The continuous-mode and the discontinuous-mode small-signal dynamic models of the magamp post regulator using the external-reset and the self-reset methods with current-mode control are presented in this paper. Based on the developed models, the dynamic performance of the magamp post regulator can be expressed in terms of circuit parameters. A procedure for designing the feedback compensation is given and experiments were conducted to verify the models
 

Drive Control



4.13.     M.B. de Rossiter Correa, C.B. Jacobina, A.M.N. Lima, E.R.C. da Silva, "Rotor-flux-oriented control of a single-phase induction motor drive ," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 832-841, Aug. 2000.  Full Text Link
Abstract : This paper investigates the vector control of a single-phase induction motor drive to implement low-cost systems for low-power applications. The static power converter side is implemented using a single-phase rectifier cascaded with a four-switch inverter. The vector control is based upon field orientation concepts that have been adapted for this type of machine. Simulation and experimental results are provided to illustrate the system operation

4. 14.     In-Joong Ha, Sang-Hoon Lee, "An online identification method for both stator-and rotor resistances of induction motors without rotational transducers," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 842-853, Aug. 2000.  Full Text Link
Abstract : This paper describes an effective online method for identifying both stator and rotor resistances, which is useful in robust speed control of induction motors without rotational transducers. The identification method for stator resistance is derived from the steady-state equations of induction motor dynamics. On the other hand, the identification method for rotor resistance is based on the linearly perturbed equations of induction motor dynamics about the operating point. The identification method for both stator and rotor resistances uses only the information of stator currents and voltages. It can provide fairly good identification accuracy regardless of load conditions and be easily incorporated into any sensorless speed controller proposed in the prior literature. Some experimental results are presented to demonstrate the practical use of the identification method. A sensorless speed control system has been built for experimental work, in which all algorithms for identification and control are implemented on a digital signal processor. The experimental results confirm that the proposed method allows for high-precision speed control of commercially available induction motors without rotational transducers

4. 15.     Yang Xia, Xinghuo Yu, W. Oghanna, "Adaptive robust fast control for induction motors," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 854-862, Aug. 2000.  Full Text Link
Abstract : A new induction motor position controller that exhibits fast response and robustness is proposed. The control strategy is based on the well-known linear quadratic regulator design principle. By adaptively adjusting a penalty parameter, it is shown that the control strategy enables the induction motor system to exhibit fast convergence. Meanwhile, since the sliding mode will occur in the transient process, the fast control inherits the robustness in matched uncertainties of the sliding-mode control. In addition, to alleviate the chattering effect of the switching control signal, a low-pass filter is used to smooth the control and its design is integrated with the switching control design. The performance of the proposed control strategy is verified by experimental results

4. 16.     P.Z. Grabowski, M.P. Kazmierkowski, B.K. Bose, F. Blaabjerg, "A simple direct-torque neuro-fuzzy control of PWM-inverter-fed induction motor drive," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 863-870, Aug. 2000.  Full Text Link
Abstract : In this paper, the concept and implementation of a new simple direct-torque neuro-fuzzy control (DTNFC) scheme for pulsewidth-modulation-inverter-fed induction motor drive are presented. An adaptive neuro-fuzzy inference system is applied to achieve high-performance decoupled flux and torque control. The theoretical principle and tuning procedure of this method are discussed. A 3 kW induction motor experimental system with digital signal processor TMS 320C31-based controller has been built to verify this approach. The simulation and laboratory experimental results, which illustrate the performance of the proposed scheme, are presented. Also, nomograms for controller design are given. It has been shown that the simple DTNFC is characterized by very fast torque and flux response, very-low-speed operation, and simple tuning capability

4. 17.     N. Hur, Kwanghee Nam, "A robust load-sharing control scheme for parallel-connected multisystems," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 871-879, Aug. 2000.  Full Text Link
Abstract : Parallel connection of inverters or converters is one useful method for solving the high power requirements. However, a load-sharing problem among parallel-connected systems is not an easy task, since crosstalk may take place among the subsystems. We develop a general methodology for solving the load sharing problem using the master-slave concept. In synthesizing the input to the slave system, we utilize system-dynamics-dependent filters. With the proposed method, we can equally distribute the load, or can give a certain offset (in load) to a specific subsystem. To show the usefulness of the proposed control scheme, we perform a simulation study with two practical systems: a current-balancing control in parallel-connected pulsewidth modulation converters and a speed and tension control for a bridle roll system in a steel mill

4. 18.     W.C. Lo, C.C. Chan, Z.Q. Zhu, Lie Xu, D. Howe, K.T. Chau, "Acoustic noise radiated by PWM-controllel induction machine drives ," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 880-889, Aug. 2000.  Full Text Link
Abstract : This paper investigates the acoustic noise radiated from two nominally identical induction motors when fed from sinusoidal, and asymmetric regular sampling subharmonic and space-vector pulsewidth modulation (PWM) converters. The theory for analyzing the noise spectrum is developed further to account for the interaction between the motor and the drive. It is shown that manufacturing tolerances can result in significant differences in the noise level emitted from nominally identical motors, and that mechanical resonances can result in extremely high noise emissions. Such resonances can be induced by stator and rotor slot air-gap field harmonics due to the fundamental component of current, and by the interaction between the airgap field harmonics produced by the fundamental and the PWM harmonic currents. The significance of the effect of PWM strategy on the noise is closely related to the mechanical resonance with vibration mode order zero, while the PWM strategy will be critical only if the dominant cause of the emitted noise is the interaction of the fundamental air-gap field and PWM harmonics

4. 19.     R.C. Kavanagh, "Improved digital tachometer with reduced sensitivity to sensor nonideality," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 890-897, Aug. 2000.  Full Text Link
Abstract : A constant sample-time digital tachometer, similar to Ohmae's “M/T” method, is described. This system is capable of accurate determination of shaft velocity, based on the outputs of an incremental encoder. Previous error analyses of such devices which consider only the asynchronous nature of counter operation are shown to be specious. It is highlighted that sensor nonidealities, including variations in the transition locations from their nominal values and phasing errors between encoder channels, can produce much larger tachometer errors. An estimate is made of the actual RMS output error, based on a simple encoder model and simplified analysis. It is shown that the error can be significantly reduced by operating four sub-circuits in parallel, each dealing with either a low-to-high or high-to-low transition of a single incremental encoder signal. A field-programmable-gate-array/digital-signal processor-based practical implementation is described. Both simulation and experimental results are presented which confirm the utility of the enhanced digital tachometer

4. 20.     Ruei-Xi Chen, Liang-Gee Chen, Lilin Chen, "System design consideration for digital wheelchair controller," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 898-907, Aug. 2000.  Full Text Link
Abstract : The design and implementation of a digital wheelchair controller system is presented in this paper. This novel model depicts an information flow between the driving commands and wheel speed. A command interpreter and two speed processing datapaths are proposed as functionally independent blocks for the controller. The control process consists of the following steps: command decoding, speed estimation, and speed serving. Through proper partitioning to concurrent blocks, the design complexity is reduced significantly. Block reconfiguration for field-programmable gate array rapid prototyping is also employed in this paper, and system fidelity and development efficiency are revealed through the experimental results

4. 21.