IEEE Transactions on Industrial Electronics 

83 forthcoming articles as of April 21   2008           Access to the journal on IEEE XPLORE     IE Transactions Home Page



1   Rachidi, F.F.; Rubinstein, M.M.; Montanya, J.J.; Bermudez, J.J. L.; Rodriguez, R.R.; Sola, G.G.; Korovkin, N.N."A Review of Current Issues in Lightning Protection of New Generation Wind Turbine Blades," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: The salient issues related to lightning protection of long wind turbine blades are discussed in this paper. We show that lightning protection of modern wind turbines presents a number of new challenges due to the geometrical, electrical and mechanical particularities of the turbines. The risk assessment for the lightning protection system design is based today solely on downward flashes. We show in this paper that the majority of the strikes to modern turbines are expected to be upward lightning. Neglecting upward flashes, as implicitly done in IEC, might result in an important underestimation of the actual number of strikes to a tall wind turbine. In addition, we show that the rotation of the blades may have a considerable influence on the number of strikes to modern wind turbines as these may be triggering their own lightning. Since wind turbines are tall structures, the lightning currents that are injected by return strokes into the turbines will be affected by reflections at the top, at the bottom, and at the junction of the blades with the static base of the turbine. This is of capital importance when calculating the protection of internal circuitry that may be affected by magnetically induced electromotive forces that depend directly on the characteristics of the current in the turbine. The presence of carbon reinforced plastics (CRP) in the blades introduces a new set of problems to be dealt with in the design of the turbines lightning protection system. One problem is the mechanical stresses resulting from the energy dissipation in CRP laminates due to the circulation of eddy currents. We evaluate in the paper the thus dissipated energy and propose recommendations as to the number of down conductors and their orientation with respect to the CRP laminates so that the dissipated energy is minimized. It is also emphasized that the high static fields under thunderclouds might have an influence on the moving carbon fiber parts. This issue needs to be addressed by-

2   Perez, M.M.A.; Espinoza, J.J.R.; Moran, L.L.A.; Torres, M.M.A.; Araya, E.E.A."A Robust Phase-Locked Loop Algorithm to Synchronize Static Power Converters With Polluted AC Systems," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A phase-locked loop algorithm appropriated for digital signal processor based control implementations where the operation of a static power converter needs to be synchronized with an AC network is presented. The proposed algorithm includes a multiplier, a filter, a feedback closed loop, and a Numerically-Controlled Oscillator stage. As a result, a discrete sine (and cosine) signal is generated in synchronism with the fundamental component of an external reference signal. Moreover, the sampling period of the algorithm is adjusted at each sampling instant such that an integer number of sampling periods per period of the external reference signal is ensured. This is the main feature and it is achieved by using a discrete rectangular window filter and a discrete controller. The proposed algorithm code is simple, stable, and presents high noise rejection. A comprehensive theoretical justification and various rigorous experimental tests are included.

3   Somasekhar, V.V.T.; Srinivas, S.S.; Kumar, K.K.K.; , .; , ."Effect of Zero-Vector Placement in a Dual-Inverter fed Open-end Winding Induction Motor Drive With a Decoupled Space Vector PWM Strategy," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: An open-end winding induction motor drive with two two-level inverters achieves three-level inversion. The drawback of this configuration is the presence of a high zero-sequence current, stressing the semi-conductor switching devices and the motor. To avoid this, two isolated DC power supplies are needed to feed individual inverters. In this paper, it is shown that it is possible to operate this drive with a single DC power supply, with reasonable engineering compromises. The new decoupled space vector based PWM strategy proposed in this paper achieves this objective. This PWM strategy exploits the dependence of the zero-sequence voltage on the placement of the zero-vector of individual inverters. It is shown that, the zero-sequence voltage of the dual-inverter system is suppressed by forcing the zero-sequence voltage of the individual inverters to a value of zero, in the average sense, in each sampling time interval. This strategy therefore achieves a dynamic balancing of the zero-sequence current. It is also shown that this PWM scheme achieves the center-spacing of effective time period for the dual-inverter drive and its associated advantages. Also, the effect of the placement of the zero-vector for individual inverters on the dual-inverter drive is investigated and the experimental results are presented.

4   Liu, Y.Y.; Hong, H.H.; Huang, A.A.Q.; , .; , ."Real-Time Calculation of Switching Angles Minimizing THD for Multilevel Inverters with Step Modulation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Multilevel inverters have been widely applied in industries. A family of optimal pulse width modulation (PWM) for multilevel inverters, such as the step modulation, can generate the output voltage with less harmonic distortion than popular modulation strategies, such as the carrier-based sinusoidal PWM or the space vector PWM. However, some drawbacks limit the application of the optimal PWM. One of such crucial drawbacks is that the optimal switching angles could not be calculated in real-time and one had to rely on look-up tables with the pre-calculated angles. We propose a novel real-time algorithm for calculating switching angles that minimizes total harmonic distortion (THD) for step modulation. We give a mathematical proof that the output voltage has the minimum THD. We implemented the algorithm on a digital signal processor (DSP) and provide experimental results that verify the performance of the proposed algorithm.

5   Eberle, W.W.; Liu, Y.Y.-F.; Sen, P.P.C.; , .; , ."A New esonant Gate Drive Circuit With efficient Energy Recovery and Low Conduction Loss," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper, a new resonant gate drive circuit is proposed to recover a portion of the power MOSFET gate energy that is typically dissipated in high frequency converters. The proposed circuit consists of four control switches and a small resonant inductance. The current through the resonant inductance is discontinuous in order to minimize circulating current conduction loss present in other methods. The proposed circuit also achieves quick turn-on and turn-off transition times to reduce switching loss and conduction loss in power MOSFETS. An analysis, design procedure and experimental results are presented for the proposed circuit. Experimental results demonstrate that the proposed driver can recover 51% of the gate energy at 5V drive voltage.

6   Iwanski, G.G.; Koczara, W.W.; , .; , .; , ."DFIG Based Power Generation System With UPS Function for Variable speed Applications," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: The power generation system with DFIG, which can be used as an autonomous power system after the loss of mains in distributed generation network, is described. After the mains outage, a fixed frequency and amplitude of the output voltage is obtained, despite of the variable rotor speed. For this reason it can be successfully applied in the variable speed wind turbines, adjustable speed water plants or diesel engines. Moreover, the stand alone operation of DFIG is useful in a flywheel based high energy rotary UPS. Output voltage is controlled directly, by the synchronization of actual voltage vector with the reference vector represented in a synchronously rotating polar frame. The rotor current angular speed is obtained as a result of vectorial phase locked loop operation. Any sensors or estimators of the rotor speed or position are unnecessary. Both amplitude and angle control loops are linear. The use of standalone operation in a grid connected systems requires mains outage detection. Also the grid voltage recovery requires a method of synchronization and soft connection of generator to the grid. The proposed methods of output voltage control, synchronization and detection of mains loss were tested in a laboratory system.

7   Kim, E.E.-H.; Kwon, J.J.-M.; Park, J.J.-K.; Kwon, B.B.-H.; , ."PracticaL Control Implementation of a Three-Phase to Single-Pahse on-Line UPS," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A high performance three-phase to single-phase on-line uninterruptible power supply (UPS) is proposed. The proposed UPS is composed of a rectifier, a battery charger/discharger, and an inverter. The rectifier has the capability of power factor correction (PFC) and regulates a dc-link voltage. When the rectifier becomes unavailable or when the current required by the load exceeds the output rating of the rectifier, the charger/discharger supplies the power demanded by the load to a dc-link capacitor. The inverter provides a regulated sinusoidal output voltage and limits an output current under an impulsive load. New control algorithms of the rectifier, the charger/discharger, and the inverter are proposed. The proposed algorithms of the rectifier and the charger/discharger improve dynamic performance at step load change. To improve the transient response of the output voltage at outage of an input source, mode change method of the charger/discharger is also proposed. Additionally, a proposed current limit algorithm of the inverter can be implemented without an additional hardware and it increases the reliability of the UPS.

8   Low, K.K.-S.; Cao, R.R.; , .; , .; , ."Model Predictive Control of Parallel Connected Inverters for Uninterruptible Power Supplies," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Uninterruptible power supplies (UPS) have been used in many installations for critical loads that can not afford power failure or surge during operation. It is often difficult to upgrade the UPS system as the load grows over time. Due to lower cost and maintenance, as well as ease of increasing system capacity, the parallel operation of modularized small power UPS has attracted much attention in recent years. In this paper, a new scheme for parallel operation of inverters is introduced. A multi-input multi-output (MIMO) state space model is developed to describe the parallel connected inverters system, and a model predictive control (MPC) scheme suitable for paralleled inverters control is proposed. In this algorithm, the control objectives of voltage tracking and current sharing are formulated using a weighted cost function. The effectiveness and the hot swap capability of the proposed parallel connected inverters system have been verified with experimental results.

9   Natori, K.K.; Ohnishi, K.K.; , .; , .; , ."A Design Method of Communication Disturbance Observer for Time Delay Compensation Taking Dynamic Property of Network Disturbance Into Account," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a design method of time delayed control systems. Because of tremendous spread of computer networks, control strategies for time delayed control systems are needed for network-based control systems (NBCSs) and other network applications. Although model-based or predictive control methods (like Smith predictor) are often used for time delay compensation, the performance often deteriorates when the value of time delay is uncertain. In these circumstances, a novel time delay compensation method based on the concept of network disturbance (ND) and communication disturbance observer (CDOB) has been proposed. The method has the same effectiveness for time delay compensation as that of Smith predictor. Furthermore, since the method works without delay time model, it can be flexibly applied to many kinds of time delayed control systems. In this paper, a design method of CDOB considering dynamic property of ND is proposed in the situation of constant time delay. Dynamic property of ND leads to two design conditions of CDOB. Those design conditions are derived considering relationships between poles of CDOB and ND dynamics. Then actual design procedure of CDOB based on derived design conditions is presented in two different delay cases. The stability of the designed control systems is clarified by stability analysis. The validity of the proposed design method is verified by experimental results. Finally, we present experimental results in the case of random delay as an example of practical application of the time delay compensation method to actual NBCSs.

10   Sreekumar, C.C.; Agarwal, V.V.; , .; , .; , ."A Hyrid Control Algorithm for Voltage Regulation in DC-DC Boost Converter," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A new switching control algorithm based on state trajectory approximation is proposed to regulate the output voltage of a representative second order dc-dc converter - the boost converter. The essence of the proposed algorithm is to trap the system into a stable limit cycle while ensuring the required voltage regulation. Unlike some of the earlier algorithms, the concept is applicable to both Continuous Current Mode (CCM) and Discontinuous Current Mode (DCM) of operation, making it viable over a wide operating range under various load and line disturbances. A hybrid automaton representation of the converter is used to perform the analysis and the control problem is simplified to a guard selection problem. Guard conditions, governing the transition of the converter operation from one discrete state to the other in a hybrid automaton representation are derived. The hybrid automaton based control system is implemented using the state flow chart feature of MATLAB and extensive simulations are carried out to check the suitability of the algorithm. The hybrid control law is also validated in real time, using a laboratory prototype. The experimental and simulation results prove the effectiveness of the proposed control law under varying line and load conditions.

11   Torrico-Bascope, R.R.P.; Oliveira Jr., D.D.S.; Branco, C.C.G.C.; Antunes, F.F.L.M.; , ."An UPS System With 110V/220V Input Voltage and High Frequency Transformer Isolation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This work proposes an isolated double conversion UPS with power factor correction using a high frequency transformer, and input voltages equal to 110V/220V. The arrangement is suitable to rack type structures because it has small size and reduced weight. For both input voltages, the proposed converter has almost the same efficiency processing the same output power. Other relevant features are soft commutation of the controlled switches in the chopper and the boost stage, simple control strategy that can be implemented with well-known integrated circuits, and the use of few batteries in series due to the step-up stage. Qualitative analysis and experimental results obtained with a 2kVA prototype show a normal efficiency of over 86% for the worst case of input voltage and an input power factor of over 99%.

12   Park, J.J.-D.; Kalev, C.C.; Hofmann, H.H.; , .; , ."Control of High-Speed Solid-Rotor Synchronous Reluctance Motor/Generator for Flywheel-Based Uninterruptible Power Supplies," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A hybrid controller, consisting of a model-based feedforward controller and a PI feedback compensator, for a solid-rotor synchronous reluctance motor/generator in a high-speed, flywheel-based uninterruptible power supply (UPS) ap-plication is proposed in this paper. The feedforward controller takes most of the control output of the current regulator based on the machine model, and the PI controllers compensate the possible inaccuracies of the model to improve the performance and robustness of the complete control system. The machine current tracking error caused by parameter inaccuracy in the model-based controller is mathematically analyzed, and utilized to dynamically compensate the estimated flux linkage to eliminate the steady-state error in current regulation. Stability analysis is also presented, and it can be seen that the regulation performance and robustness of the system are improved by the proposed hybrid controller. Simulation and experimental results consisting of a flywheel energy storage system validates the performance of the controller.

13   Pascual, M.M.; Garcera, G.G.; Figueres, E.E.; Gonzalez-Espin, F.F.; , ."Robust Model-Following Control of parallel UPS Single-Phase Inverters," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a robust control technique applied to modular UPS inverters operating in parallel. When compared to conventional PI control, the proposed technique improves the response of the output voltage to load steps and to high distorted output currents, reducing the distortion of the output voltage. Furthermore, an excellent distribution of currents between modules is achieved, resulting in a fine power equalization between the inverters on stream. The crossover frequency of the different loop gains involved is moderate, so that robustness to variations of the operation point and to modelling uncertainties is achieved. A comparative study with a two-loop conventional PI control scheme is presented. Experimental results on a 1 kVA modular online UPS system confirm the viability of the proposed scheme.

14   Rodriguez, E.E.; Vazquez, N.N.; Hernandez, C.C.; Correa, J.J.; , ."A Novel AC-UPS With High Power Factor and Fast Dynamic Response," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a novel AC UPS scheme with high power factor, which offers excellent characteristics such as: sinusoidal input current, sinusoidal output voltage, fast regulation of the AC-mains, galvanic isolation and fast transient response. The proposed converter includes the concept off-on line, which avoids the continuous charging and discharging of the battery as it occurs in typical on-line UPS. Analysis and design considerations as well as simulation and experimental results are given in this paper

15   Bo, Y.Y.; Oruganti, R.R.; Panda, S.S.K.; Bhat, A.A.K.S.; , ."An Output Power Control Strategy for a Three-Phase PWM Rectifier Under Unbalanced Supply Conditions," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Instantaneous power regulation is an effective way to improve the performance of a PWM rectifier operating under unbalanced supply voltage conditions. By properly setting current commands, this approach aims to achieve performance features normally achievable only under ideal balanced operating conditions. This paper proposes an instantaneous power regulation strategy, called output power control method, in which the current commands are determined so as to distribute the input power appropriately for maintaining a constant dc output voltage and sinusoidal line currents. Though the power factor is not directly controlled, it is shown that the proposed scheme results in near unity vector power factor. The current commands are given by a set of simple linear equations using which the proposed control scheme can be easily implemented. Experimental results obtained with a 1 kW laboratory prototype demonstrate that the proposed scheme fulfils all the main objectives of a high performance rectifier.

16   Carpita, M.M.; Marchesoni, M.M.; Pellerin, M.M.; Moser, D.D.; , ."Multilevel Converter for Traction Applications: Small Scale Prototype Tests Results," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract:

17   Chen, L.L.-R.; Chu, N.N.-Y.; Wang, C.C.-S.; Liang, R.R.-H.; , ."Design of a Reflex-Based Bidirectional Converter With the Energy Recovery Function," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper, a reflex charging strategy with the energy recovery function for a bidirectional converter (BC) is proposed to build a novel reflex-based BC (RBC) for increasing the battery charging efficiency in an uninterruptible power supply (UPS). The proposed RBC can provide a reflex charging current profile to charge the battery to obtain a high battery charging efficiency and prolong the battery life cycle. Specially, negative pulse energy of the reflex charging current profile in the proposed RBC is recovered to reduce the battery charging dissipation. A soft transfer method is also developed in this paper to really erase the spike current in the RBC. A 400W prototype is design and implemented to verify the feasibility of the proposed RBC. Compared with a typical bidirectional converter, the battery charging efficiency, the battery charging speed and the battery thermal deterioration effect are improved about 10%, 8.8% and 7% by the proposed RBC, respectively.

18   Arias, M.M.; Fernandez, A.A.; Lamar, D.D.G.; Rodriguez, M.M.; Hernando, M.M.M."Simplified Voltage Sag Filler for Line-Interactive Uninterruptible Power Supplies," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: There are three types of Static Uninterruptible Power Supplies (UPS): passive standby, line-interactive and double conversion. The last one protects the load against all types of line disturbances but it is the most expensive and the one with the lowest efficiency. On the other hand, passive standby and line-interactive UPS have higher efficiency and lower cost, but they show an important drawback: a switching time from normal mode to stored-energy mode. As a consequence, there is a notch in the UPS output voltage during this switching time. In a previous paper, authors proposed a method for filling these voltage notches with a sinusoidal waveform generated by a switch-mode converter. In this one, a simplified notch filler is proposed. It consists of two capacitors charged one with positive and the other with negative voltage. If the fault occurs in the positive period, the positive charged capacitor is connected to the load. This connection is then modulated in order to obtain a sinusoidal waveform at the load. In the negative period, the other capacitor is used in the same way.

19   Busquets-Monge, S.S.; Ortega, J.J.D.; Bordonau, J.J.; Beristain, J.J.A.; Rocabert, J.J."Closed-Loop Control of a Three-Phase Neutral-Point-Clamped Inverter Using an Optimized Virtual-Vector-Based Pulsewidth Modulation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a closed-loop control scheme for the three-level three-phase neutral-point-clamped dc-ac converter using the optimized nearest-three virtual-space-vector pulsewidth modulation, a modulation that produces a low output voltage distortion with a significant reduction of the dc-link capacitance. A new specific loop modifying the modulating waveforms is proposed to rapidly control possible perturbations in the neutral-point voltage balance. An online estimation of the load displacement angle and load linear/nonlinear nature is introduced at no extra cost. The remaining part of the control is analogous to the control for a two-level converter with an appropriate interfacing to the selected modulation. The closed-loop control is designed for the case of a renewable energy source connected to the ac mains and its performance is analyzed through simulation and experiments.

20   Chang, T.T.; Ansari, N.N.; , .; , .; , ."Passband Control of Lightly Damped Systems With Mode Separation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper deals with the regulation and stabilization of lightly damped systems under plant uncertainty. A controller consisting of a neural network based mode separator together with a modular passband tuning regulator is proposed. The mode separator generates the in phase components of the plant utilized by the passband tuning regulator to maintain closed loop stability and asymptotic regulation. This combined controller is robust and requires minimal plant information to operate. A synthesis procedure is outlined in this paper to summarize the design steps in a systematic manner. Finally, application of the passband controller to the stabilization of a magnetic leadscrew is considered. Resonance is shown to be completely eliminated. Stabilization time of the transient response is also significantly reduced, confirming the feasibility of the controller.

21   Cirrincione, M.M.; Pucci, M.M.; Vitale, G.G.; , .; , ."A Single-Phase DG Generation Unit With Shunt Active Power Filter Capability by Adaptive Neural Filtering," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper deals with a single-phase Distributed Generation (DG) system with Active Power Filtering (APF) capability, devised for utility current harmonic compensation. The idea is to integrate the DG unit functions with the shunt APF capabilities, since the DG is connected in parallel to the grid. With the proposed approach, the control of the DG unit is performed by injecting into the grid a current with the same phase and frequency of the grid voltage and with amplitude depending on the power available from the renewable sources. On the other hand, the load harmonic current compensation is performed by injecting into the AC system harmonic currents like those of the load but with opposite phase, thus keeping the line current almost sinusoidal. Both the detection of the grid voltage fundamental and the computation of the load harmonic compensation current have been performed by two neural adaptive filters with the same structure, one in configuration notch and the other in the complementary configuration band . The notch filter has been used to compute the compensating current by eliminating only the contribution of the fundamental of the load current, while the band configuration is able to extract the fundamental of the coupling point voltage. Furthermore, since the active power generation and the APF features require respectively current control of components at different frequencies, a multiresonant current controller has been adopted. The methodology has been tested successfully both in numerical simulation and experimentally on a suitably devised test setup. The stability analysis of the proposed control approach has been performed in the discrete domain.

22   He, Z.Z.; Xing, Y.Y.; , .; , .; , ."Distributed Cotnrol for UPS Modules in Parallel Operation With RMS Voltage Regulation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A novel distributed control for Uninterruptible Power Supply (UPS) modules in parallel operation is proposed in this paper, in which the voltage reference synchronization control and load current distribution control are decoupled by local feedback. The voltage reference is pre-synchronized beyond the current distribution control with a micro controller unit (MCU) and a wired-AND circuit. Both instantaneous current distribution and hot-swapping of any module are allowed with all the UPS modules electrically isolated. The transfer function of the circulating current regulator is analyzed and equivalent to a first-order low-pass filter. The control characteristics of the root-mean-square voltage regulator (RMSVR) in each UPS module in parallel operation are researched, as well as the coupling effect between the RMSVR and the load balance performance. The RMSVR s impact on current distribution is compensated by introducing the amplitude of the output current or the circulating current into the amplitude adjustment of the sinusoidal voltage reference signal. As a result, both the current sharing and the output voltage performance of the whole system are effectively improved. Theoretic analysis and experimental results are provided to demonstrate the validity and feasibility of the proposed control.

23   Jager, M.M.; Humbert, S.S.; Hamprecht, F.F.A.; , .; , ."Sputter Tracking for the Automatic Monitoring of Industrial Laser Welding Processes," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: The importance of laser welding in industry increases. Many welds have high quality demands and one possibility to satisfy the quality requirements is to monitor the welding process with high speed cameras. Laser welding is a highly dynamic process, it is therefore challenging to distinguish between normal process fluctuations and abnormal error events in the recorded sequences. This paper investigates a novel classification method to automatically analyze the recorded welding sequences and robustly find the abnormal error events. To our knowledge it is the first time that a framework to detect and track sputters in welding sequences is proposed and evaluated. To achieve a high usability of the classification algorithm, in the training phase the user only needs to mark suspicious sequences, but does not need to label individual frames within the sequences. The framework is tested on two challenging datasets from real welding processes. The results show that the material particles can be tracked accurately. On a sample dataset, the new approach finds all erroneous welds with a small false positive rate and outperforms previously developed methods.

24   Mattavelli, P.P.; Polo, F.F.; Dal Lago, F.F.; Saggini, S.S.; , ."Analysis of Control Delay Reduction for the Inprovement of UPS Voltage Loop Bandwidth," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper investigates the effects of control delay minimization in the dynamic performance of the output stage of Uninterruptible Power Supplies (UPSs) by shifting the sampling time of inductor current and output voltage toward the duty-cycle update instant. This paper shows how a small shift of the output voltage sampling can significantly increase the UPS voltage loop bandwidth while keeping the same stability margin. Instead, less contribution comes from the delay minimization of the inductor current sampling, so that current ripple cancellation techniques are not needed. A detailed model based on the modified Z-transform, which accounts for different time delays in multi-loop control, is proposed. The effectiveness of the proposed analysis is demonstrated by simulation and experimental results on a typical industrial three-phase/three-phase 8 kHz, 30 kVA UPS prototype. Using two control design based on the same phase margin, the output voltage THD with the normalized distorting load is reduced from 6.8% to 5.7% delaying the output voltage sampling of 25 ¼ s.

25   Ordaz-Moreno, A.A.; Romero-Trocoso, R.R.J.; Vite-Frias, J.J.A.; Rivera-Gillen, J.J.R.; Garcia-Perez, A.A."Automatic On-Line Diagnosis Algorithm for Broken Bar Detection on Induction Motors Based on Discrete Wavelet Transform for FPGA Implementation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Overall system performance on a production line is one of the major concerns in modern industry where induction motors are present and their condition monitoring is mandatory. Periodic off-line monitoring of the motor condition is usually performed at the industry, consuming production time and increasing cost. Broken rotor bars are one of most common failures on induction motors. Reported researches give a broken rotor bar detection methodology based on PC implementation that is performed off-line and require an expert technician interpretation which is not a cost-effective solution. The novelty of this paper is the development of an automatic on-line diagnosis algorithm for broken rotor bar detection, optimized for single low-cost FPGA implementation, which guarantees the development of economical self-operated equipment. The proposed algorithm requires less computation load than the previously reported algorithms and it is mainly based on the discrete wavelet transform application to the start-up current transient; a further single mean square computation determines a weighting function that according to its value clearly points the motor condition as healthy or damaged. In order to validate the proposed algorithm, several tests were performed and an FPGA implementation was developed to show the algorithm feasibility for automatic on-line diagnosis.

26   Park, J.J.K.; Kwon, J.J.M.; Kim, E.E.H.; Kwon, B.B.H.; , ."High Performance Transformerless On-Line UPS," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A high performance single-phase transformerless on-line uninterruptible power supply (UPS) is proposed. The proposed UPS is composed of a four-leg-type converter which operates as a rectifier, a battery charger/discharger, and an inverter. The rectifier has the capability of power factor collection (PFC) and regulates a constant dc-link voltage. The battery charger/discharger eliminates the need for the transformer and the increase of the number of battery and supplies the power demanded by the load to the dc-link capacitor in the event of the input power failure or abrupt decrease of the input voltage. The inverter provides a regulated sinusoidal output voltage to the load and limits the output current under an impulsive load. The control of the dc-link voltage enhances the transient response of the output voltage and the utilization of the input power. By utilizing the battery charger/discharger, the overall efficiency of the system is improved and the size, weight, and cost of the system are significantly reduced. Experimental results obtained with a 3kVA prototype show a normal efficiency of over 95.6% and an input power factor of over 99.7%.

27   Tao, H.H.; Duarte, J.J.L.; Hendrix, M.M.A.M.; , .; , ."Line-Interactive UPS Using a Fuel Cell as the primary Source," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper proposes a line-interactive fuel cell powered uninterruptible power supply (UPS) system. A three- port bidirectional converter connects a fuel cell and a superca- pacitor to a grid-interfacing inverter. The system can operate in both stand-alone and grid-connected modes. Moreover, an active filtering function is integrated into the system. It is shown that a supercapacitor can serve as both an active and a reactive energy storage, and buffers the periodical low-frequency ripple in the requested power. For connecting the system to the utility grid, a high-performance single-phase phase locked loop (PLL) that incorporates an orthogonal filter is presented. Resonant controllers for both the voltage and current regulation eliminate steady-state error and implement selective harmonic compensa- tion. Simulation and experimental results are provided to show the feasibility of the proposed system and the effectiveness of the control methods.

28   Motai, Y.Y.; Kosaka, A.A."Hand-Eye Calibration Applied to Viewpoint Selection for Robotic Vision," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Viewpoint calibration is a method to manipulate hand-eye for generating calibration parameters for active viewpoint control and object grasping. In robot vision applications, accurate vision sensor calibration and robust vision-based robot control are essential for developing an intelligent and autonomous robotic system. This paper presents a new approach to hand-eye robotic calibration for vision-based object modeling and grasping. Our method provides a 1.0-pixel level of image registration accuracy when a standard Puma/Kawasaki robot generates an arbitrary viewpoint. In order to attain this accuracy, our new formalism of hand-eye calibration deals with a lens distortion model of a vision sensor. Our most distinguished approach of optimizing intrinsic parameters is to utilize a new parameter estimation algorithm using an extended Kalman filter. Most previous approaches did not even consider the optimal estimates of the intrinsic and extrinsic camera parameters, or chose one of the estimates obtained from multiple solutions, which caused a large amount of estimation error in hand-eye calibration. We demonstrate the power of this new method for (1) generating 3D object models using an interactive 3D modeling editor, (2) recognizing 3D objects using stereo vision systems, and (3) grasping 3D objects using a manipulator. Experimental results using both a Puma and a Kawasaki robot are shown.

29   Lee, S.S.-S.; Moon, G.G.-W."Full ZVS-Range Transient Current Build-up Half Bridge Converter With Different ZVS Operation to Load Variation," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A full ZVS (Zero Voltage Switching) range transient current build-up half-bridge converter is proposed. The proposed converter controls the secondary synchronous switches to build-up the current for the ZVS operation. In addition, the blocking capacitor in the secondary side of transformer is used to make the different current build-up and different ZVS operations with the load variation. Furthermore, it eliminates the DC offset of magnetizing current. Therefore, the considerably effective ZVS characteristics can be ensured in the full load ranges without any additional conduction losses.

30   Wu, M.M.; She, J.J.-H.; Zeng, G.G.-X.; Ohyama, Y.Y."Internet-Based Teaching and Experiment System for Control Engineering Course," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: e-learning engineering courses with on-line experiments are attracting a great deal of attention because of the flexibility they provide in both teaching and learning. This paper describes an Internet-based teaching and experiment system for control engineering (ITESCE) that provides students with on-line course material, a simulator, an on-line control experiment using an arm robot, and the ability to store and search simulation and experimental results. To implement the functions required by the course and to facilitate connection to the Internet, the ITESCE is based on a standard B/S architecture with three layers and employs multithreading, Java applets, and JDBC. Background control subsystems handle the real-time control of experiments, and a network server handles communication with clients and with background control subsystems. A database stores simulation and experimental results. The course covers a variety of control methods, and students can try them out through on-line simulations and experiments. To enhance realism, a web camera takes video of an experiment and streams it to a student's PC in real time.

31   Dalapati, S.S.; Chakraborty, C.C."A Direct PWM Technique for a Single-Phase Full-Bridge Inverter Through Controlled Capacitor Charging," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Controlled capacitor charging (CCC) technique is utilized here to synthesize a sinusoidal voltage at the output from the unregulated dc at the input. The method is based on controlled charging/discharging of a capacitor to realize the desired voltage waveform. A capacitor that is connected across the load is charged/discharged through an inductor by applying high frequency pulses. Applied pulses could be of either positive or negative polarity depending on the error signal in the controller. The controller senses the output-voltage and current and operates to maintain zero current switching (ZCS) at every turn-on, while keeping the output-voltage close to the reference waveform by a tracking control algorithm enforcing limits in maximum switching frequency and voltage ripples. This paper presents a direct method of implementing the PWM for the single-phase, full-bridge inverter using the CCC technique. A simple procedure to design such inverter is also discussed. The proposed controller is simulated in PSPICE. Supporting results from experimental prototype confirm the usefulness of the proposed controller. The inverter may be used in UPS and many other applications.

32   Escobar, G.G.; Hernandez-Briones, P.P. G.; Martinez, P.P. R.; Hernandez-Gomez, M.M.; Torres-Olguin, R.R. E."A Repetitive-Based Controller for the Compensation of 6l + 1 Harmonic Components," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper, a repetitive based controller for the compensation of the 6 ±1 harmonic components is proposed. This control scheme is more appropriate for processes which involve the use of six pulse converters or other converters that produce mainly harmonic components at those frequencies. The control scheme is based on the feedback array of two delay lines plus a feedforward path which compensate the 6 ±1 multiples of the fundamental frequency only, and thereby reducing the possibility of reinjecting unnecessary distortion into the system. The proposed scheme is then plugged in to a generic feedback control system where a stability analysis is carried out. Also the passivity properties of the proposed scheme are presented which open the possibility of control design following the passivity based approach. Experiments, based on a simple digital implementation, are provided to illustrate the merits of our solution. These results include the open loop responses of the proposed scheme, and the responses in a practical example to validate its effectiveness in an application. For this latter, the proposed scheme has been used in the controller of a 2 KVA shunt active filter to compensate the current harmonic distortion.

33   Chen, J.J.-J.; Lin, H.H.-C.; Kung, C.C.-M.; Hwang, Y.Y.-S.; Su, J.J.-H."Integrated Class-D Amplifier With Active Current Sensing Suitable for Alternating Current Switches," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: An integrated class-D amplifier with active current sensing suitable for alternating current switches is presented in this paper. The proposed current-sensing technique is used to sense and control the inductor current at the output stage and allows the current-sensing element to be integrated into class-D amplifiers. To verify the performance of the proposed circuits, a class-D amplifier was designed and fabricated with 3.3-V, 0.35-¼ m double-poly quadruple-metal CMOS technology on a chip area that is 1.79mm*1.45mm. Maximum power efficiency of the class-D amplifier can be up to 94% for an 8 load. These active current-sensing circuits can be applied to other power converters with alternating current switches.

34   Wai, R.R.-J.; Lin, C.C.-Y.; Lin, C.C.-Y.; Dunn, R.R.-Y.; Chang, Y.Y.-R."High-Efficiency Power Conversion System for KW-Level Stand-Alone Generation Unit With Low Input Voltage," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This study mainly focuses on the development of a high-efficiency power conversion system for kW-level stand-alone generation units with low output voltage, such as photovoltaic (PV) modules, fuel cells (FC), and small-scale wind generators, and it aims to have the same output ac voltage 110Vrms/60Hz as the utility power for the utilization of a stand-alone power supply. This high-efficiency power conversion system includes one high-efficiency, high step-up dc-dc converter and one soft-switching dc-ac current-source inverter. This dc-dc converter is capable of solving the voltage spike problem while the switch is turned off, and it can achieve the objectives of high efficiency and high voltage gain. Because the techniques of soft switching and voltage clamping are used in the dc-ac current-source inverter, the conversion efficiency could be greatly improved. The effectiveness of the designed circuits is verified by experimentations, and the maximum efficiency of the entire high-efficiency power conversion system is over 91% from the experimental measurements.

35   Chuang, Y.Y.-C.; Ke, Y.Y.-L."High Efficiency and Low Stresses ZVT-PWM DC-to-DC Converter for Battery Charger," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This work presents a novel highly efficient and low-stress battery charger with a resonant-switch converter-based on resonance and zero-voltage-transition (ZVT) soft-switching theory-that reduces defects associated with high voltage and high current stresses caused by the resonance of traditional resonant circuits. The novel battery charger meets the requirement that all circuit components must operate with zero-voltage switching. Experimental test results indicate that the proposed battery charger reduces the temperature of an active power switch and switching losses are less than those obtained using a traditional pulse-width-modulation (PWM) converter as a battery charger.

36   Bierhoff, M.M. H.; Fuchs, F.F. W."DC Link Harmonics of Three Phase Voltage Source Converters Influenced by the Pulse Width Modulation Strategy - An Analysis," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: DC link current harmonics are the predominant factor to be considered for dimensioning DC capacitors in three phase PWM voltage source converters. In this article an analysis of the DC link current harmonics applying double Fourier series is derived. The analytical results for the DC link current spectra of continuous and discontinuous PWM are presented and compared with measurement results taken from a converter test setup. A good match between theoretically expected and actually obtained experimental results can be stated. Moreover characteristic differences between the investigated modulation strategies regarding their DC link current spectra become evident.

37   Lo, Y.Y.-K.; Lee, T.T.-P.; Wu, K.K.-H."Grid-Connected Photovoltaic System With Power Factor Correction," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A combined grid-connection/power factor correction technique for a photovoltaic (PV) system is proposed in this letter. The maximum power point tracking DC/DC converter is also served as a charger of the battery bank. The bi-directional inverter is applied as a generator/discharger at day time, supplying power to the load. The inverter also can be used as a charger, to maintain the minimum required voltage level of the batteries when the PV power is insufficient. Experiments on a 1-kW PV system show satisfactory results of the power management and the unity power factor (PF) at the utility side.

38   Gonzalez, D.D.; Bialasiewicz, J.J. T.; Balcells, J.J.; Gago, J.J."Wavelet-Based Performance Evaluation of Power Converters Operating With Modulated Switching Frequency," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: It has been demonstrated that modulating the switching frequency of a power converter is a valuable way for reducing EMI due to the switching process. Since we are considering a signal whose frequency content varies with time, wavelets are well suited to analyze the performance of such techniques. In this paper, we evaluate the performance of Spread Spectrum Frequency Modulation (SSFM) applied to the EMI reduction of a real power converter that uses periodic-pattern switching frequency modulation. Performance of the converter under investigation includes analysis of the switching voltage spectrum (as the main source of EMI) and output voltage ripple. This evaluation is performed with two coefficients, MER and EDR, which are figures of merit defined in this paper using time-dependent energy density distribution in frequency, obtained from the scalograms of analyzed signals. Such figures of merit allow the comparison in time-frequency domain of different modulation techniques and the choice of the best solution for each case in terms of reduction of the peak of noise spectrum.

39   Chen, R.R.-T."Capacitor-Based Multi-Source of Flyback-Type Power Collector," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents multi-source power collection method based on the electric addition in capacitor for renewable energy application. Instead of combining input sources in the magnetic form, the proposed flyback-type collector combines input dc sources in electric form by adding up the electric energy together in the capacitors. With the pulse width modulation control, the proposed collector can draw power from larger three different dc sources and deliver it to the battery individually and simultaneously. The operating principle of the proposed collector with three different input-stages has been analyzed in detail. The output voltage regulation and power budget can be achieved by the phase-shifted PWM control. Two prototypes of collector system with three different dc voltage sources have been successfully implemented to verify the performance of the power collector.

40   Prieto-Blazquez, J.J.; Arnedo-Moreno, J.J.; Herrera-Joancomarti, J.J."An Integrated Structure for a Virtual Networking Laboratory," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A Virtual Laboratory is a virtual space where students are able to carry out practical activities. This paper presents an integrated structure for a Virtual Laboratory consisting on nine resources divided into pedagogical, human and technological factors. Such a structure is based on the experience gained in design and development of Virtual Laboratories during the past eleven years in a virtual university. The proposed structure has been applied to different Virtual Laboratories and this paper presents the special case of a Virtual Networking Laboratory (VNLab) where students can access real networking devices. The VNLab structure described in this paper has been used at the Open University of Catalonia for the Cisco Networking Academic since 2001. Its suitability has been evaluated by the students using a web questionnaire and its correctness for the Industrial Electronics field has been analyzed.

41   Wu, C.C.-Y.; Wu, T.T.-F.; Tsai, J.J.-R.; Chen, Y.Y.-M.; Chen, C.C.-C."Multi-String LED Backlight Driving System for LCD Panels With Color Sequential Display and Area Control," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper, a multi-string light emitting diode (LED) backlight driving system for liquid crystal display (LCD) panels with color sequential display (CSD) and area control is proposed. In large-scale LCD panels, multi-string LED backlights are required to provide sufficient back lighting. The most popular structure to achieve multi-string current regulation is a current mirror. However, it cannot be applied to high power LED ( >100 mA ) driving, and the number of LEDs in each string is highly limited. In the driving system, a multi-output flyback converter associated with a novel control IC is proposed to regulate LED driving currents tightly, and to achieve CSD and area control readily. The proposed driving system for a 32-inch LCD panel has been built, from which experimental measurements have verified that the proposed driving system has the following features: low power consumption, high power conversion efficiency, stable driving currents, and high reliability.

42   Zheng, L.L.; Fletcher, J.J.E.; Williams, B.B.W.; He, X.X.; , ."Dual-Plane Vector Control of a Five-Phase Induction Machine for an Improved Flux Pattern," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A technique to improve the flux pattern within a five-phase induction machine is presented. The technique is developed through dual-plane vector control, with synchronized fluxes. By vector space decomposition, an analytical model and vector control of the machine are accomplished in two orthogonal vector planes, d1-q1 and d3-q3. The magnitude and rotating speed of the associated fluxes fundamental and third harmonic) can be independently controlled in each vector plane. Synchronization control locks the relative position between the two fluxes. The resultant air-gap flux density is fully controlled, preventing iron saturation. This feature is especially important in reshaping the flux and back-EMF waveform of the machine. A quasi-trapezoidal air-gap flux density distribution is achieved for better iron utilization and higher torque density. It is confirmed that compared with sinusoidal fluxing, the quasi-trapezoidal flux pattern will not lead to an oversized power inverter when i proving machine torque density. The basic understanding and control scheme can be extended to a multi-phase induction machine with a phase number greater than five.

43   Chau, K.K.T.; Chan, C.C.C.; Liu, C.C.; , .; , ."Overview of Permanent Magnet Brushless Drives for Electric and Hybrid Electric Vehicles," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: With ever increasing concern on our environment, there is a fast growing interest in electric vehicle (EV ) and hybrid EV (HEV ) from automakers, governments and customers. As electric drive are the core of both EV and HEV , it is a pressing need for researcher to develop advanced electric drive systems. In this paper, an overview of permanent magnet (PM) brushless drives for EVs and HEVs is presented, with emphasis on machine topologies, drive operations and control trategies. Then, three major research directions of PM brushless drive system are elaborated: namely, the magnetic geared outer-rotor PM brushless drive system, the PM brushless integrated starter-generator (ISG) system, and the PM brushless electric variable transmission (EVT) system.

44   Mutoh, N.N.; Yusuke, T.T.; Tomita, Y.Y.; , .; , ."Failsafe Drive Performance of Electric Vehicles with the Structure Drive by the Front and Rear Wheels Independently," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Failsafe performance is clarified for electric vehicles (EVs) with the drive structure driven by front and rear wheels independently. A simulator based on the four-wheel vehicle model which can be applied to various types of drive systems like four in-wheel motor drive type EVs is used for the clarification. Yaw rate and skid angle which are related to drivability and steerability of vehicles and which further influence the safety of vehicles during runs are analyzed under the condition that one of the motor drive systems fails while cornering on wet roads. In comparison with four in-wheel motor drive type EVs, it is confirmed that the EVs with the structure focused on here have little change of the yaw rate and hardly any dangerous phenomena appear which would cause an increase in the skid angle of vehicles even if the front or rear wheel drive system fails when running on wet roads with low friction coefficient. Moreover, the failsafe drive performance of the EVs with the above structure is verified through experiments using a prototype EV.

45   Fortunato, M.M.; Giustiniani, A.A.; Petrone, G.G.; Spagnuolo, G.G.; Vitelli, M.M."Maximum Power Point Tracking in a One Cycle Controlled Single Stage Photovoltaic Inverter," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper the design of the one cycle controller of a single stage inverter for photovoltaic applications is carried out by means of a multi-objective strategy, in order to optimize the inverter performances at both high and low insolation levels. Design constraints keeping into account the different possible weather conditions are adopted. The optimization algorithm also provides useful information concerning the system sensitivity with respect to each one of the controller parameters. his allows to design a maximum power point tracking perturb and observe controller that significantly improves the inverter performances. Experimental measurements confirm the predictions of theoretical an simulation results.

46   Kim, S.S.; Park, F.F. C."Fast Robot Motion Generation Using Principal Components: Framework and Algorithms," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: We present a principal component-based method for generating, in real-time, fast robot motions that approximately minimize power consumption. Given a dynamic model of a robot, a sufficiently large set of torque-minimum motions are obtained for pre-selected initial and final positions that also achieve minimum time while avoiding actuator saturation. These motions are then clustered according to the trajectory endpoints and shape. A principal component analysis is performed for each motion cluster, and the dominant principal components are sued as basis functions in a linear interpolation scheme for generating fast, torque-efficient motions between arbitrary initial and final positions. Results obtained for both a six-axis industrial manipulator and a wheeled mobile robot demonstrate that nearly optimal motions can be obtained in real-time using this scheme.

47   Mohamed, Y.Y.A.R.I.; El-Saadany, E.E.F.; , .; , .; , ."A Control Scheme of PWM-Voltage-Sourced Distributed Generation Inverters for Fast Load Voltage Regulation and Effective Mitigation of Unbalanced Voltage Disturbances," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a control scheme for grid-connected pulse-width-modulated (PWM) voltage-sourced inverters (VSIs) featuring fast load voltage regulation and effective mitigation of unbalanced voltage disturbances. To ensure perfect regulation of the voltage at the point of common coupling (PCC) and providing means for rejecting fast and dynamic voltage disturbances, the frequency modes of the disturbances to be eliminated should be included in the stable closed loop system. Toward this, a hybrid voltage controller combining a linear with variable-structure control (VSC) element is proposed to for an inverter-based distributed generation (DG) interface to regulate the voltage at the PCC. The proposed voltage controller can embed a wide band of frequency modes through an equivalent internal model. Subsequently, wide range of voltage perturbations, including capacitor-switching disturbances, can be rejected. To account for unbalanced voltage disturbances, a dual-sequence voltage controller is proposed. To provide accurate and robust tracking of the generated active and reactive current trajectories, a newly designed deadbeat current control algorithm is proposed. The controller is designed under the practical considerations of inherent plant delays, associated with the digital implementation of the control algorithm, and the uncertain nature of the current dynamics. Theoretical analysis and comparative evaluation tests are presented to demonstrate the effectiveness of the proposed control scheme.

48   Mastromauro, R.R.A.; Liserre, M.M.; Dell'Aquila, A.A.; , .; , ."Study of the Effects of Inductor Non-Linear Behavior on the Performance of Current Controllers for Single-Phase PV Grid Converter," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Resonant and repetitive controllers are well suited for single-phase grid-connected inverter due to the optimum tracking and harmonics rejection capability. In particular, in this paper their application for single-phase photovoltaic (PV) systems is considered. The effects of non-linear inductance on the performance of current controllers designed to track periodic signals and/or to compensate periodic disturbances are investigated. When the inductance has a non-linear behavior a distorted current waveform is produced. Two different non-linearities have been considered: saturation for high currents and a light non-linearity which occurs in the first portion of the magnetization curve for low currents. A current-dependent model of the non-linear inductance has been developed. It is mathematically based on the Volterra series expansion and it allows proving how harmonic compensation provided by resonant and repetitive controllers can also mitigate the effects of the inductance saturation. This result is the main contribution of the paper and it is also substantiated with experimental evidence. Moreover the repetitive controller is able to comply with the harmonic limits reported in IEEE 1547 and IEC 61727 even in very hard saturation conditions.

49   Trevisan, D.D.; Mattavelli, P.P.; Tenti, P.P."Digital Control of Single-Inductor Multiple-Output Step-Down dc-dc Converters in CCM," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper investigates the application of digital control for non-isolated single-inductor multiple-output step-down dc-dc converters operating in Continuous-Conduction Mode (CCM). The accurate and independent control of each output requires sophisticated digital control architecture so as to minimize the cross-regulation problem. The adopted control includes a separate regulation of common-mode and differential-mode output voltage. Due to the differential-mode control loop dependence on the load current, a variable gain functional block has been investigated; this provision keeps the differential-mode loop gain constant under different load conditions. Moreover, a non-linear evaluation of the common-mode voltage have been investigated in order to improve the system dynamic response to asymmetrical load changes. Even if aimed to an integrated solution, experimental verifications have been performed using discrete components, implementing the digital control in a Field Programmable Gate Array (FPGA). Simulation results on a three output converter and experimental results on dual output converter ( Vin = 2.5 ÷5V , Vo1 = Vo2 = 0.9 ÷1.5V , Io1 = Io2 = 0 ÷ 0.6A ) confirm the proposed analysis.

50   Trigg, M.M. C.; Nayar, C.C. V."DC Bus Compensation for a Sinusoidal Voltage Source Inverter With Wave-Shaping Control," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a study on the effects of different parameters on the DC bus voltage of a single-phase voltage controlled voltage source inverter with conventional load voltage RMS feedback control and a wave-shaping controller. It is shown that load voltage RMS feedback control and the wave-shaping controller require compensation for fluctuations in the DC bus voltage caused by the battery and lead wire resistance and lead wire inductance. DC bus voltage compensation is shown to provide performance improvements, including better load voltage regulation and less load voltage distortion. Mathematical modeling, computer simulations and experimental results based on a 2kVA single-phase full-bridge voltage controlled voltage source inverter are presented.

51   Vazquez, N.N.; Villegas-Saucillo, J.J.; Hernandez, C.C.; Rodriguez, E.E.; Arau, J.J."Two Stage Uninterruptible Power Supply With High Power Factor," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: An uninterruptible power supply with high power factor and two conversion stages is suggested. The double conversion configuration has three stages, but normally only two are operating at the same time. The first stage of the proposed scheme integrates the power factor correction stage and the battery charger of the double conversion configuration, obtaining a two stage uninterruptible power supply. The second stage is based on the theory of inverter with boosting capabilities. The battery set has not been only completely isolated, but also it has been charged with a small change at the controller set point; these particular characteristics facilitate the system maintenance and simplify its operation. Additionally the battery set voltage is low reducing the weight and size. The converter operation, analysis, design and experimental results are shown. The proposed UPS approach is practical in low power applications (d 500W).

52   Xu, W.W.L.; Torrance, J.J.D.; Chen, B.B.Q.; Potgieter, J.J.; Bronlund, J.J.E.; Pap, J.J.-S."Kinematics and Experiments of a Life-Sized Masticatory Robot for Characterizing Food Texture," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A life-sized masticatory robot of 6RSS parallel mechanism is dealt with in the paper, which is intended to chew foods in a human way while the food properties are evaluated. The robotic mechanism is proposed and its kinematic parameters are defined according to the biomechanical findings and measurements of the human masticatory system. For a given mandibular trajectory to be tracked, the closed form solution to inverse kinematics of the robot is found for joint actuations while differential kinematics is derived in Jacobian. Major features of the built robot including the motion control system are presented. Experimental results for free chewing, soft-food chewing and hard-food chewing are given where the foods are simulated by foam and hard objects, and crank actuations and driving torques (an indication of muscular activities) required are compared for the chewing of different foods.

53   Fu, C.C.; Chen, K.K."Gait Synthesis and Sensory Control of Stair-Climbing for a Humanoid Robot," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Stable and robust walking in various environments is one of the most important abilities for a humanoid robot. This paper addresses walking pattern synthesis and sensory feedback control for humanoid stair-climbing. The proposed stair-climbing gait is formulated to satisfy the environmental constraint, the kinematic constraint, and the stability constraint; the selection of the gait parameters is formulated as a constrained nonlinear optimization problem. The sensory feedback controller is phase-dependent and consists of the torso attitude controller, the zero moment point compensator, and the impact reducer. Online learning scheme of the proposed feedback controller is based on a policy gradient reinforcement learning method, and the learned controller is robust against external disturbance. The effectiveness of our proposed method was confirmed by walking experiments on a 32 degree-of-freedom humanoid robot.

54   Ignaciuk, P.P.; Bartoszewicz, A.A."Linear Quadratic Optimal Discrete Time Sliding Mode Controller for Connection," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper a new sliding mode flow controller for connection-oriented communication networks is proposed. The networks are modeled as discrete time, n-th order systems. On the basis of the system state space description a novel, sliding mode controller with linear quadratic optimal switching plane is designed. Two control laws are proposed, each derived by minimizing different cost functionals. The first law is obtained when the whole state vector is considered in the optimization procedure, while in the latter case the derivation concentrates on the system output variable with additional weighting coefficient introduced into the cost functional. Closed loop system stability is demonstrated, and conditions for no data loss and full bottleneck link bandwidth utilization in the network are presented, and strictly proved. According to our best knowledge, this paper presents the first attempt to design a discrete time sliding mode flow control algorithm for connection-oriented communication networks.

55   Kim, S.S.-Y.; Ha, I.I.-J."A New Observer Design Method for HF Signal Injection Sensorless Control of IPMSMs," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: We present a systematic approach to the design of an observer for rotor position and velocity of interior permanent magnet synchronous motors (IPMSMs) without rotational transducers, in which the effects of both motor and filter dynamics are taken into full account. The proposed observer can be incorporated directly into the well-known high-frequency voltage injection methods.

56   Khaligh, A.A.; , .; , .; , .; , ."Realization of Parasitics in Stability of Dcall-Dc Converters Loaded by Constant-Power Loads in Advanced Multi-Converter Automotive Systems," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Distributed dc power systems are becoming increasingly common in advanced automotive systems. Constant power load (CPL) behavior of tightly regulated dc-dc converters in multi-converter power systems is equivalent to the dynamic negative impedance, destabilizing the dc bus and consequently the system. Various techniques have been developed to control ideal/lossless converters loaded by CPLs. Loss components significantly enhance the stability of the cascaded converters. In this paper, effects of parasitics in behavior of dc-dc converters loaded by CPLs are investigated. Furthermore, stability of power converters loaded by CPLs in parallel to conventional constant voltage loads in presence of loss components is analyzed. Design criteria are presented for converter operation in continuous conduction mode (CCM) and discontinuous conduction mode (DCM), which gives recommendations on the design of multi-converter dc power systems to avoid negative impedance instability. The proposed stable operation criteria are validated with hardware prototypes and simulation analyses.

57   Kim, C.C.-E.; Moon, G.G.-W."Input Voltage Feed-Forward (IVFF) Circuit Minimizing Current Stress of Voltage Doubler Rectified Asymmetrical Half-Bridge (VDRAHB) Converter," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A new input voltage feed-forward (IVFF) circuit for Voltage Doubler Rectified Asymmetrical Half-Bridge (VDRAHB) converter is proposed in this letter. The proposed circuit regulates output voltage not by reducing duty ratio but by increasing switching frequency as input voltage increases. Therefore, by employing the proposed IVFF circuit into VDRAHB converter, the peak currents of the overall components can be greatly reduced and also efficiency can be improved at high input voltage.

58   Baughman, A.A.C.; Ferdowsi, M.M.; , .; , .; , ."Double-Tiered Switched-Capacitor Battery Charge Equalization Technique," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: The auto industry is progressing towards hybrid, plug-in hybrid, and fully electric vehicles in their future car models. Energy storage unit is one of the most important blocks in the powertrain of future electric drive vehicles. Batteries and/or ultracapacitors are the most prominent storage systems utilized so far. Hence, their reliability during the lifetime of the vehicle is of great importance. Charge equalization of series-connected batteries or ultracapacitor is essential due to the capacity imbalances stemming from manufacturing, ensuing driving environment, and operational usage. Double-tiered capacitive charge shuttling technique is introduced and applied to a battery system in order to balance the battery cells voltages. Parameters in the system are varied and their effects on the performance of the system are determined. Results are compared to a single-tiered approach. MATLAB simulation shows a substantial improvement in charge transport using the new topology. Experimental results verifying simulation are presented.

59   Hur, J.J.; , .; , .; , .; , ."Characteristic Analysis of Interior Permanent Magnet Synchronous Motor in Electro-Hydraulic Power Steering Systems," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents design and analysis results of a 2.6kW interior permanent magnet synchronous motor (IPMSM) developed for an electro-hydraulic power steering system (EHPS). The motor was designed by using the proposed equivalent magnetic circuit model in consideration with a core loss. To analyze motor characteristics by using the equivalent magnetic circuit model, inductance and iron loss resistance, which are affected critically magnetic saturation, are obtained by using finite element analysis (FEA). Finally, motor characteristics such as armature current, torque and efficiency, are calculated by the equivalent magnetic circuit model and verified by experimental results.

60   Lukic, S.S.; Cao, J.J.; Bansal, R.R.; Rodriguez, F.F.; Emadi, A.A."Energy Storage Systems for Automotive Applications," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: The fuel efficiency and performance of novel vehicles with electric propulsion capability are largely limited by the performance of the energy storage system (ESS). This paper reviews the state of the art of ESSs which are in use in automotive applications. Battery technology options are considered in detail, with emphasis on methods of battery monitoring, managing, protecting and balancing. Furthermore, other ESS candidates such as ultracapacitors, flywheels and fuel cells are also discussed. Finally hybrid power sources are considered as a method of combining two or more energy storage devices to get a superior power source.

61   Xiong, Y.Y.; Cheng, X.X.; Shen, Z.Z.J.; Mi, C.C.; Wu, H.H.; Garg, V.V."Prognostic and Warning System for Power Electronic Modules in Electric, Hybrid Electric, and Fuel Cell Vehicles," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Reliability of power electronics modules is of paramount importance for the commercial success of various types of electric vehicles. In this paper, we study the technical feasibility of detecting and utilizing early symptoms and warning signs of power module degradation due to thermomechanical stress and fatigue, and develop a prognostic system that can monitor the state of health of the power modules in electric, hybrid, and fuel cell vehicles . A special degradation trace on the VCEsat of the IGBT modules was observed by power cycling accelerated test, which was not reported in literatures. A prognostic system based on utilizing above trace is then developed. The system consists of the hardware architecture and current adaptive algorithm based software architecture. In addition, this prognostic system hardly increases the hardware cost on existing vehicle driver system. An extensive simulation based on Matlab/Simulink verifies the developed prognostic system.

62   Saggini, S.S.; Mattavelli, P.P.; Garcea, G.G.; Ghioni, M.M."A Mixed-signal Synchronous/Asynchronous Control for High Frequency dc-dc Boost Converters," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper investigates the application of a mixed-signal synchronous/asynchronous digital controller to dc-dc boost converters. The digital control synchronously generates current and voltage ramps by using two low-resolution Digital-to-Analog Converters (DACs). Switch turn-on and turn-off are determined asynchronously by comparing converter state variables and the digitally generated current and voltage ramps. The control features high dynamic performance, frequency modulation during transients, no quantization effects, and low-complexity. In order to evaluate the dynamic performance and to compare the proposed solution with conventional analog peak current mode control, a small signal model of the synchronous/asynchronous modulation is derived. Even if aimed to an integrated digital controller, experimental investigation has been performed using discrete components, implementing the digital control in a Field Programmable Gate Array (FPGA) using a hardware description language (VHDL). Simulation and experimental results on 100 W dc-dc boost converter confirm the proposed analysis and shows that the proposed solution enables dynamic performance comparable to that of analog peak current-mode control.

63   Alcaso, A.A. N.; Marques Cardoso, A.A. J."Remedial Operating Strategies for a Twelve-Pulse LCI Drive System," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper reports on the study of the Load Commutated Inverter drive, operating with an open-switch fault in the line-side converters. To improve this faulty operation some strategies are presented, in order to decrease the harmonic content of currents and the pulsating torque of the motor. To validate the proposed strategies, experimental results are presented.

64   Duran, M.M.; Salas, F.F.; Arahal, M.M."Bifurcation Analysis of Five-Phase Induction Motor Drives with Third Harmonic Injection," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: The interest in variable-speed multi-phase induction-motor drives has substantially increased in recent years and novel proposals show good prospects for industrial implementation in high-power applications. The additional degrees of freedom existing in multi-phase machines have allowed for new applications with high torque density by current harmonic injection in concentrated winding machines. This paper addresses, for the first time, the bifurcation analysis of a five-phase induction-motor drive when a third harmonic is injected for torque-enhancement purposes. The main focus of the paper is to present a mathematically based study of the non-linear dynamics of the proposed drive with torque enhancement. The overall bifurcation analysis for both concentrated and distributed winding machines, confirms that the harmonic injection provides not only torque enhancement but also more robust controllers. This further advantage offers improved performance of multi-phase drives compared to their three-phase counterparts.

65   Jacobina, C.C. B.; de Freitas, I.I. S.; da Silva, C.C. R.; de R. Correa, M.M. B.; da Silva, E.E. R. C."Reduced Switch Count Six-Phase AC Motor Drive Systems Without Input Reactor," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper, two reduced switch count six-phase ac motor drives are investigated. The first configuration considered has six legs (Configuration 6 ) and the second one has five legs (Configuration 5 ) and uses the capacitor dc-link midpoint connection. Both configurations operate without input reactors and provide both bidirectional power flow and power factor control. 60 o and 30 o six-phase induction machine windings are employed. Operating principles and control strategies for the topologies are presented. The proposed configurations are compared to the full-bridge (nine legs) topology and the half-bridge (six legs) topology, which uses the capacitor dc-link midpoint connection. These drive systems are suitable for applications in which the size of the system is a critical factor. Experimental and simulation results are presented.

66   Boglietti, A.A.; Bojoi, R.R.; Cavagnino, A.A.; Tenconi, A.A."Efficiency Analysis of PWM Inverter Fed Three-Phase and Dual Three-Phase High Frequency Induction Machines for Low-Medium Power Applications," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: A performance analysis of three-phase and dual three-phase induction Pulse Width Modulation (PWM) inverter fed motor drives is conducted in this paper. The focus is on the efficiency performance of high-frequency dual-three phase machines compared to their three-phase counterparts in low/medium power applications. For this purpose, a dual three-phase machine, having two sets of stator three-phase windings spatially shifted by 30 electrical degrees (asymmetrical six-phase winding configuration), has been tested for both six-phase and three-phase winding configurations under the same magnetic conditions. Simulation and experimental results are presented to evaluate the efficiency performance of three-phase and dual-three induction motor drives employing PWM Voltage-Source Inverters (VSI).

67   Kiani-Nezhad, R.R.; Nehid-Mobarakeh, B.B.; Baghli, L.L.; Betin, F.F.; Capolino, G.G.-A."Modeling and Control of Six-Phase Symmetrical Induction Machine Under Fault Condition due to Open Phases," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper introduces a new fault-tolerant operation method for a symmetrical six-phase induction machine (6PIM) when one or several phases are lost. A general decoupled model of the induction machine with up to three open phases is given. This model illustrates the existence of a pulsating torque when phases are opened. Then, a new control method reducing the pulsating torque and the motor losses is proposed in order to improve the drive performances. The proposed method is compared to two other existing techniques. The simulation and experimental results obtained on a dedicated test-rig confirm the validity and the efficiency of the proposed method for a fault-tolerant symmetrical six-phase induction machine drive.

68   Casadei, D.D.; Dujic, D.D.; Levi, E.E.; Sierra, G.G.; Tani, A.A.; Zarri, L.L."General Modulation Strategy for Seven-Phase Inverters with Independent Control of Multiple Voltage Space Vectors," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper focuses on the analysis of a seven-phase voltage source inverter for high performance motor drives. The problem of the modulation strategy of the inverter is solved by combining the multiple space vector representation with traditional carrier-based Pulse Width Modulation. This approach leads to the definition of a general modulation strategy that can be usefully utilized in multi-motor drives, as well as in multi-phase motor drives for improving the torque density. The inverter output voltage capability is investigated, showing that the proposed modulation strategy is able to fully exploit the dc input voltage either in sinusoidal or non-sinusoidal operating conditions. The results obtained in the analytical investigation are confirmed by experimental tests.

69   Levi, E.E."Multiphase Electric Machines for Variable Speed Applications," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Although the concept of variable speed drives, based on utilization of multiphase (n > 3) machines, dates back to the late sixties of the last century, it was not until the mid to late nineties that multiphase drives have become serious contenders for various applications. These include electric ship propulsion, locomotive traction, electric and hybrid electric vehicles, more-electric aircraft, and high power industrial applications. As a consequence, there has been a substantial increase in the interest for such drive systems world-wide, resulting in a huge volume of work published during the last ten years. An attempt is made in this paper to provide a brief review of the current state-of-the-art in the area. After addressing the reasons for potential use of multiphase rather than three-phase drives and the available approaches to multiphase machine designs, various control schemes are surveyed. This is followed by the discussion of the multiphase voltage source inverter control. Various possibilities for the use of additional degrees of freedom that exist in multiphase machines are further elaborated. Finally, the multiphase machine applications in electric energy generation are addressed.

70   Dujic, D.D.; Grandi, G.G.; Jones, M.M.; Levi, E.E."A Space Vector PWM Scheme for Multi-Frequency Output Voltage Generation with Multi-Phase Voltage Source Inverters," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: Multi-phase variable speed drives, supplied from two-level voltage source inverters (VSIs), are nowadays considered for various industrial applications. Depending on the drive structure and/or the motor design, the VSI is required to generate either sinusoidal voltages or voltages that contain a certain number of sinusoidal components ( multi-frequency output voltages ). The existing space vector PWM (SVPWM) schemes are based on selection of (ncrn 1) active space vectors (for odd phase numbers) within a switching period and they yield either sinusoidal voltage or sinusoidal fundamental voltage in combination with a limited amount of other harmonic terms. This paper develops a SVPWM scheme, which enables multi-frequency output voltage generation with arbitrary values of various sinusoidal components in the output voltage. The method is based on initial selection of (ncrn 1)2 /2 active space vectors within a switching period, instead of the common (ncrn 1) active vectors. By properly arranging the sequence of the vector application it is possible to provide an automatic post-reduction of the number of applied active vectors to (ncrn 1), thus maintaining the same switching frequency as with the existing schemes while simultaneously avoiding the limiting on the generated sinusoidal output voltage components. Theoretical considerations are detailed using a five-phase VSI. The experimental verification is provided using a five-phase two-motor series-connected induction motor drive, supplied from a custom-designed five-phase DSP-controlled VSI.

71   Marouani, K.K.; Baghli, L.L.; Hadiouche, D.D.; Kheloui, A.A.; Rezzoug, A.A."A New PWM Strategy Based on a 24-Sector Vector Space Decomposition for a Six-Phase VSI-Fed Dual Stator Induction Motor," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: This paper presents a new space vector PWM technique for the control of six-phase voltage source inverter-fed dual stator induction machines (DSIM). A DSIM is an induction machine which has two sets of three-phase stator windings spatially shifted by 30 electrical degrees and fed by two three-phase voltage source inverters. Despite their advantage of power segmentation, these machines are characterized by large zero sequence harmonic currents, and in particular those of order 6k±1, which are due to the mutual cancellation between the two stator windings. The proposed SVPWM scheme, while easy to implement digitally, reduces significantly these extra stator harmonic currents. Experimental results, collected from a 15 kW prototype machine controlled by a digital signal processor (DSP) are presented and discussed.

72   Shamsi-Nejad, M.M.-A.; Nahid-Mobarakeh, B.B.; Pierfederici, S.S.; Meibody-Tabar, F.F."Fault Tolerant and Minimum Loss Control of Double-Star Synchronous Machines Under Open Phase Conditions," Trans. on Industrial Electronics, vol. 55, no.? , pp. 1-1, 2008.   Abstract Link    Full Text

Abstract: In this paper, a new method for filtering the torque pulsations is proposed for double-star permanent magnet synchronous machines under fault conditions. The machine is supplied by two independent electric sources via two voltage source inverters. The proposed method deals with the case where an open-circuit fault occurs. In order to reduce the torque pulsations, the usual solution consists in supplying only the healthy star winding. Here, we propose to supply not only the healthy winding, but also the two remaining phases of the other star winding by the healthy legs of the faulty inverter. The stator current waveforms can be easily determined to minimize the copper losses while reducing the torque pulsations. Simulation and experimental results confirm the efficiency of the proposed method.

73   Bialasiewicz, J.J. T."Renewable Energy Systems With Photovoltaic Power Generators: Operation and Modeling," Trans. on Industrial Electronics, vol. 55, no.? , p