IEEE Transactions on Industrial Electronics
IEEE Transactions on Industrial Electronics
Power Electronics
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
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
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. 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
21. E.G. Marra, J.A. Pomilio, "Induction-generator-based system providing regulated voltage with constant frequency," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 908-914, Aug. 2000. Full Text Link
Abstract : The electrical characteristics of an isolated induction-generator-based system are improved through the association with a voltage-source pulsewidth modulation (PWM) inverter. The electronic converter allows the achievement of a better system behavior in many aspects: voltage regulation, frequency stabilization, and reactive power compensation. The system operation strategy consists of maintaining constant synchronous frequency at the induction generator via an association with a PWM inverter. The system power balance and the generator voltage regulation may be accomplished by two different means: through the rotor speed regulation, or by sending part of the energy stored in the inverter DC side to the grid through a single-phase line, in case the rotor speed is not regulated and a single-phase grid connection is available. The obtained results demonstrated the system is stable, robust, and an effective source of regulated three-phase voltages
Robotics and Vision
22. P. Pillay, Yaguang Liu, O.G. Durham, "A novel switched reluctance motor drive with optical graphical programming technology," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 915-919, Aug. 2000. Full Text Link
Abstract : Due to magnetic nonlinearities, switched reluctance motor (SRM) drive control is complicated and normally requires a microprocessor or a digital signal processor. This paper presents a simple and reliable SRM drive using an innovative encoder based on optical graphical programming technology. There is no microprocessor in the drive, no A/D or D/A circuitry, with a drive system that matches the simplicity of the motor construction. It features a simple and effective control capability. Current waveform optimization for the encoder is carried out offline, for high efficiency, and programmed directly into the encoder. Experimental results validate the concept
23. R.C. Luo, Tse Min Chen, "Autonomous mobile target tracking system based on grey-fuzzy control algorithm," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 920-931, Aug. 2000. Full Text Link
Abstract : This paper presents a new position-based tracking system for autonomous mobile target tracking task. A grey-fuzzy controller (GFC) is developed for motion control of the tracker, in which dynamics models of the target and tracker are not required a priori. The target detection is based on the adaptive visual detector (AVD), which can online adjust the histogram model based on the change of surrounding conditions, such as light variation, in a natural environment. The AVD and GFC are integrated together for mobile target-tracking applications. There are several advantages of the integrated system, in particular: (1) it can rapidly learn the target appearance model for the detection involved with the tracking task; (2) the temporal dynamics model of the target motion can be approximated for the predictive localization of the moving target; and (3) the system can deal with the uncertain environmental conditions to ensure the tracking performance by GFC. Three mobile robots in the authors' laboratory have been used to demonstrate the success of this integrated system experimentally. They also conduct target tracking experiments, in which Chung Cheng-I tracks various moving targets. The results demonstrate the robustness and flexibility of the overall system in dealing with mobile target-tracking problems under varied natural environment conditions
24. Wen-Hua Chen, D.J. Ballance, P.J. Gawthrop, J. O'Reilly, "A nonlinear disturbance observer for robotic manipulators," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 932-938, Aug. 2000. Full Text Link
Abstract : A new nonlinear disturbance observer (NDO) for robotic manipulators is derived in this paper. The global exponential stability of the proposed disturbance observer (DO) is guaranteed by selecting design parameters, which depend on the maximum velocity and physical parameters of robotic manipulators. This new observer overcomes the disadvantages of existing DOs, which are designed or analyzed by linear system techniques. It can be applied in robotic manipulators for various purposes such as friction compensation, independent joint control, sensorless torque control and fault diagnosis. The performance of the proposed observer is demonstrated by the friction estimation and compensation for a two-link robotic manipulator. Both simulation and experimental results show the NDO works well
Factory Automation
25. D.M. Wilson, E.D. Blom, M.A. Marra, B.L. Walcott, "Direct sensorimotor control for low-cost mobile tracking applications," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 939-950, Aug. 2000. Full Text Link
Abstract : A biologically inspired system for tracking objects in a visual scene is presented. The uniqueness of the system is in the absence of a microcontroller to convert sensory information to tracking decisions, reducing power, size, weight, and cost of the overall system. The system consists of a mobile vehicle outfitted with a custom analog VLSI architecture for encoding the position of an object of interest in the vehicles's field of view. Once determined, the object of interest retains hysteresis proportional to its size and intensity to limit the potential for distraction by other objects in the sensing environment. The encoded position of the object of interest is directly converted to a series of motor control signals to drive the vehicle in the direction of the object. The motor drive signals are pulse width modulated to control the speed and direction of travel induced by two de motors via a conventional differential steering arrangement. Neural oscillators are used to drive the de motors to provide a compact single-chip system for tracking bright objects. The nature of the system is sufficiently modular so that it can be adapted relatively easily to tracking other features of visual objects and even to objects representative of other sensing modalities. The system described here is one of the first efforts to fully integrate and apply analog VLSI (aVLSI) sensorimotor control to a mobile vehicle and to analyze the complete system from a control systems' perspective. The system described here has the advantages of aVLSI integration in its small size (0.011-mm2 elements), low power (0.3 μW per element), and fast system response time (1.5 ms from sensory input to motor response)
Emerging Technologies
26. G. Cena, A. Valenzano, "FastCAN: a high-performance enhanced CAN-like network," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 951-963, Aug. 2000. Full Text Link
Abstract : The controller area network (CAN) is a real-time fieldbus network which today is very popular in industrial environments because of its very appealing characteristics and low implementation costs. It has, however, serious limitations regarding the network extension and the transmission speed which may rule out this protocol in the next few years, at least for the use in high-performance automation systems. This paper presents a modification to the conventional CAN protocol based on a dual channel topology, which overcomes those limitations and exhibits a behavior that is very similar to the original standard protocol. FastCAN features very high communication performance and ensures a certain degree of compatibility with the existing devices and applications developed for the conventional CAN networks
Letters to the Editor
27. K. Matsuo, "Laser observation of flying ink jet electrostatically extracted: main results and application to tone reproduction of images," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 964-970, Aug. 2000. Full Text Link
Abstract : At present, there are several methods for measuring the diameter of droplets of ink jets. The authors have conceived a method by which not only the droplet diameter but also the state of ink jet flight can be determined using the same optical system by changing the light source only. The electrostatically extracted ink jet method using dielectric ink was used for the experiment. In the case of electrostatically extracted ink jet, a liquid thread of continuous flow is generated from the nozzle tip and disperses in corpuscles from the leading edge of the liquid thread. Observation of dispersing ink flight is difficult by any of the conventional methods. In their study, the state of ink from the liquid thread to corpuscles was observed by controlling applied voltage and ink pressure and with the use of an He-Ne laser beam or dye pulse laser beam depending on the observation objectives. Interesting results obtained are reported in this paper. In designing commercial models of printers using ink jets, their observation method presents new aspects for examining the state of flying ink
28. F.M.P. Hidalgo, J.R.H. Larmbia, J.L.D. Pat, "Ripple reduction in DC line of a PWM drive by direct reinjection ," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 971-973, Aug. 2000. Full Text Link
Abstract : This letter describes an alternative solution to passive and active filter arrangements on the DC side of the power converter. The circuits of DC-side ripple elimination are based on direct reinjection of the ripple in series with the DC line
29. Ming-Tsung Tsai, C. Tsai, "Energy recycling for electrical AC power source burn-in test," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 974-976, Aug. 2000. Full Text Link
Abstract : This letter presents a feasible method for electrical AC power source burn-in test. The proposed architecture consists of two power stages. It consumes a lesser amount of energy than the conventional method and provides extra flexibility for the test load. To implement the proposed idea, a simple control strategy and system design is presented in this letter. A case study for an adjustable-speed AC motor drive is demonstrated by means of a prototype experiment to prove its performance and effectiveness
30. Yu-Kang Lo, Huang-Jen Chiu, Tzu-Herng Song, "A software-based CM and DM measurement system for the conducted EMI ," Trans. on Industrial Electronics, vol. 47, no. 4, pp. 977-978, Aug. 2000. Full Text Link
Abstract : In this letter, a software-based measurement system for conducted EMI is presented. A friendly interface is developed to provide an effective communication between the user and the system, the amplitude of either common-mode or differential-mode noise can be obtained by calculations. Experiments show that the proposed system works well on certain types of equipment