IEEE Transactions on Industrial Electronics

Volume 48, Number 3, June 2001 Access to the journal on IEEE XPLORE IE Transactions Home Page

Power Electronics

48.3.1	A. Raciti, G. Belverde, A. Galluzzo, G. Greco, M. Melito, S. Musumeci, "Control of the switching transients of IGBT series strings by high-performance drive units," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 482-490, June 2001. Abstract Link Full Text Abstract: In the field of power electronics, the use of series-connected insulated gate devices, such as insulated gate bipolar transistors or power MOSFETs, is interesting in order to obtain fast and efficient power switches in medium-range power converters. In this kind of application, the control of the voltage sharing across the series strings of devices is an important aspect to be considered. The proposed technique allows obtaining safe commutations of the switches by simple and effective control circuits acting on the gate side of the power devices. In particular, the gate drive units are arranged in order to ensure good performance during the switching transients, while preventing overvoltage peaks on the devices. Both the design criteria and analysis of the control circuit are developed. Several experimental tests are reported in order to demonstrate the validity and correctness of the proposed approach
48.3.2	Woo-Cheol Lee, Taeck-Kie Lee, Dong-Seok Hyun, "Comparison of single-sensor current control in the DC link for three-phase voltage-source PWM converters," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 491-505, June 2001. Abstract Link Full Text Abstract: This paper presents a technique for reconstructing converter line currents using the information from a single current sensor in the DC link of a converter and comparative evaluation of the performance of single sensor control techniques in the DC link for voltage-source pulsewidth modulation (V-S PWM) converters. When 3φ input currents cannot be reconstructed, three methods to acquire the DC-link current are compared. Two of them are methods of modifying the switching state (I, II), and another is a method of using the predictive state observer. Also, compensation of sampling delay, and a simultaneous sample value of input currents in the center of a switching period are included. Suitable criteria for the comparison are identified, and the differences in the performance of these methods are investigated through experimental results for a typical V-S PWM converter rated at 10 kVA
48.3.3	S.J. Chiang, C.Y. Yen, K.T. Chang, "A multimodule parallelable series-connected PWM voltage regulator ," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 506-516, June 2001. Abstract Link Full Text Abstract: This paper presents the analysis and design of a single-phase voltage regulator (VR) and its multinodule parallel control. The VR employs the pulsewidth modulation three-arm rectifier-inverter topology. The inverter side adjusts the load voltage with the series regulating structure aiming to minimize converter capacity and attain higher efficiency. The rectifier side regenerates the load power and executes the active power filter function to achieve unity power factor. Based on such high-performance VR, a resistive droop method combined with the P-V droop and Q-δ shift scheme is then proposed to control the current sharing such that multiple VRs can be paralleled directly without any control interconnection. The proposed parallel control technique possesses the features of fast response, precise voltage regulation, equal fundamental and harmonic current sharing, tolerance for parameter mismatch, and so on. Two prototype 1 KVA VRs are implemented, and the effectiveness is demonstrated by some simulation and experimental results
48.3.4	C.B. Jacobina, M.B.deR. Correa, T.M. Oliveiro, A.M.N. Lima, E.R.C. da Silva, "Current control of unbalanced electrical systems," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 517-525, June 2001. Abstract Link Full Text Abstract: The vector modeling approach is employed to describe the behavior of unbalanced three-phase (three-wire), unbalanced two-phase and single-phase systems. In the case of single-phase systems, a fictitious circuit is introduced in order to create the vector model. Continuous-time and discrete-time current controllers based on the vector approach are presented. The current control scheme is based on two controllers, one for the positive sequence and another for the negative sequence. The controllers are implemented in the synchronous reference frame and in the stationary reference frame. In the stationary reference frame, the use of the same integral gains for both controllers simplifies the equations of the control law especially for single-phase systems. Simulation and experimental results obtained with a pulsewidth modulation voltage-source inverter supplying unbalanced systems are presented
48.3.5	D. Graovac, V. Katic, "Online control of current-source-type active rectifier using transfer function approach," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 526-535, June 2001. Abstract Link Full Text Abstract: Current-source topology AC/DC converters (buck converters) operated using pulsewidth modulation have significant drawbacks in lack of line current control and AC-side filter damping. Also, an AC-side filter is usually overrated in order to keep harmonic distortion under imposed limits. Discontinuous current at converter line inputs disables the use of current control techniques known from control of voltage-source converters. In order to overcome these problems, an online control method for the buck converter is presented in this paper. This method is based on the AC filter transfer function approach. Such an approach enables a novel solution for line-side filter optimization in the case of hysteresis line current control. This method leads to a filter with minimal apparent power (cost) and the fast and accurate converter's control response. Furthermore, a line current estimation method was developed. It uses only one current sensor at the converter DC side in order to estimate power supply currents. Suggested methods were numerically and experimentally verified
48.3.6	Jung-Won Kim, Jung-Sik Yon, B.H. Cho, "Modeling, control, and design of input-series-output-parallel-connected converter for high-speed-train power system," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 536-544, June 2001. Abstract Link Full Text Abstract: In this paper, a charge control with an input voltage feedforward is proposed for an input-series-output-parallel-connected converter configuration for the high-speed-train power system application. This control scheme accomplishes the output current sharing. For the output-parallel-connected modules as well as the input voltage sharing for the input-series-connected modules for all operating conditions including the transients. It also offers the robustness for the input voltage sharing control according to the component value mismatches among the modules. This configuration enables the usage of a MOSFET for a high-voltage system allowing a higher switching frequency for a lighter system weight and smaller size. The performance of the proposed scheme is verified through the experimental results
48.3.7	J.-W. Kang, S.-K. Sul, "Analysis and prediction of inverter switching frequency in direct torque control of induction machine based on hysteresis bands and machine parameters," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 545-553, June 2001. Abstract Link Full Text Abstract: In this paper, the influences of the hysteresis bands on the direct torque control (DTC) of an induction motor are analytically investigated, and the switching frequency of the inverter is predicted based on the analysis. The flux and torque hysteresis bands are the only gains to be adjusted in DTC, and the inverter switching frequency and the current waveform are greatly influenced by them. Therefore, the magnitude of the hysteresis band should be determined based on reasonable guidelines which can avoid excessive inverter switching frequency and current harmonics in the whole operating region. This paper predicts the inverter switching frequency according to torque and flux hysteresis bands based on induction machine parameters and control sampling period, and investigates the effect of hysteresis bands to line current harmonics. The simulated and experimental results prove the usefulness and feasibility of the proposed method
48.3.8	Han-Woong Park, Sung-Jun Park, Jin-Gil Park, Cheul-U Kim, "A novel high-performance voltage regulator for single-phase AC sources," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 554-562, June 2001. Abstract Link Full Text Abstract: Regulation of load voltage in single-phase applications is becoming an important issue for critical loads. This paper presents a novel high-performance single-phase voltage regulator which has a common arm between the rectifier and inverter, and adopts an appropriate switching strategy. The proposed voltage regulator employs six switches and can be implemented by only one three-phase inverter module. The proposed voltage regulator has the capability of delivering sinusoidal input current with unity power factor, good output voltage regulation, and bidirectional power flow. For these purposes, a fully digital controller is designed and implemented using a TMS320F240 digital signal processor. In addition, a novel low-cost AC capacitor is also presented. This type of capacitor requires two DC capacitors and two diodes, enabling low-cost and compact manufacturing. Consequently, the complete voltage regulator system, which is mainly suitable for an uninterruptible power supply as well as reactive or nonlinear loads, can be constructed compactly and inexpensively. Experimental results are presented to verify the feasibility of the proposed voltage regulator system
48.3.9	D. Biel, E. Fossas, F. Guinjoan, E. Alarcon, A. Poveda, "Application of sliding-mode control to the design of a buck-based sinusoidal generator," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 563-571, June 2001. Abstract Link Full Text Abstract: This paper is devoted to the design of a sliding-mode control scheme for a buck-based inverter, with programmable amplitude, frequency, and DC offset, with no external sinusoidal reference required. A general procedure for obtaining an autonomous (time independent) switching surface from a time-dependent one is presented. For this surface, the system exhibits a zeroth-order dynamics in sliding motion. On the other hand, from the sliding-domain analysis, a set of design restrictions is established in terms of the inverter output filter Bode diagram and the output signal parameters (amplitude, frequency and DC offset), facilitating the subsequent design procedure. The control scheme is robust with respect to both power-stage parameter variations and external disturbances and can be implemented by means of conventional electronic circuitry. Simulations and experimental results for both reactive and nonlinear loads are presented
48.3.10	Jun-Young Lee, Myung-Joong Youn, "A single-stage power-factor-correction converter with simple link voltage suppressing circuit (LVSC)," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 572-584, June 2001. Abstract Link Full Text Abstract: A single-stage power-factor-correction AC/DC converter with a simple link voltage suppressing circuit (LVSC) for the universal line application is proposed. A portion of the energy charged in a boost inductor is directly transferred to a load via LVSC without passing the link capacitor. Using simple circuitry, a low link voltage can be realized without input current deadbands at line zero crossings. The proposed converter is analyzed and design guidelines for the proper operation of a converter are given. A universal input (90-265-V_rms) prototype converter with 5-V 12-A output is implemented to verify performance. The experimental results show that the maximum link voltage stress and efficiency are about 447 V and 81%, respectively. The power factor is above 0.96 under the universal line condition when the load is higher than 30%
48.3.11	Guan-Chyun Hsieh, Liang-Rui Chen, Kuo-Shun Huang, "Fuzzy-controlled Li-ion battery charge system with active state-of-charge controller," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 585-593, June 2001. Abstract Link Full Text Abstract: A fuzzy-controlled active state-of-charge controller (FC-ASCC) for improving the charging behavior of a lithium-ion (Li-ion) battery is proposed. The proposed FC-ASCC is designed to replace the general constant-voltage charging mode by two kinds of modes: sense and charge. A fuzzy-controlled algorithm is built with the predicted charger performance to program the charging trajectory faster and to keep the charge operation in a proposed safe-charge area (SCA). A modeling work is conducted for analyzing and describing the Li-ion battery in charging process. A three-dimensional Y-mesh diagram for describing the charging trajectories of the proposed FC charger is simulated. A prototype of a Li-ion battery charger with FC-ASCC is simulated and realized to assess the predicted charging performance. Experiment shows that the charging speed of the proposed FC charger compared with the general one increases about 23% and the charger can safely work in the SCA
48.3.12	Yeong-Chau Kuo, Tsorng-Juu Liang, Jiann-Fuh Chen, "Novel maximum-power-point-tracking controller for photovoltaic energy conversion system," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 594-601, June 2001. Abstract Link Full Text Abstract: A novel maximum-power-point-tracking (MPPT) controller for a photovoltaic (PV) energy conversion system is presented. Using the slope of power versus voltage of a PV array, the proposed MPPT controller allows the conversion system to track the maximum power point very rapidly. As opposed to conventional two-stage designs, a single-stage configuration is implemented, resulting in size and weight reduction and increased efficiency. The proposed system acts as a solar generator on sunny days, in addition to working as an active power line conditioner on rainy days. Finally, computer simulations and experimental results demonstrate the superior performance of the proposed technique Drive Control
48.3.13	Sung-Don Wee, Myoung-Ho Shin, Dong-Seok Hyun, "Stator-flux-oriented control of induction motor considering iron loss," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 602-608, June 2001. Abstract Link Full Text Abstract: Research to consider the influences of iron loss has been made in the vector control of an induction motor. However, little work has been done in the area of a stator-flux-oriented control system of an induction motor. This paper investigates the effects of iron loss in the direct stator-flux-oriented control system of an induction motor, and proposes a control algorithm considering iron loss. The iron loss is modeled by equivalent iron loss resistance in parallel to the magnetizing inductance. Torque control capability is much improved and the speed estimation error for a speed-sensorless drive is reduced by the proposed control algorithm. The effectiveness of the proposed method is verified by simulation and experimental results
48.3.14	Seong-Hwan Kim, Tae-Sik Park, Ji-Yoon Yoo, Gwi-Tae Park, "Speed-sensorless vector control of an induction motor using neural network speed estimation," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 609-614, June 2001. Abstract Link Full Text Abstract: In this paper, a novel speed estimation method of an induction motor using neural networks (NNs) is presented. The NN speed estimator is trained online by using the error backpropagation algorithm, and the training starts simultaneously with the induction motor working. The estimated speed is then fed back in the speed control loop, and the speed-sensorless vector drive is realized. The proposed NN speed estimator has shown good performance in the transient and steady states, and also at either variable-speed operation or load variation. The validity and the usefulness of the proposed algorithm are thoroughly verified with experiments on fully digitalized 2.2 kW induction motor drive systems
48.3.15	Kuo-Kai Shyu, Chiu-Keng Lai, J.Y. Hung, "Totally invariant state feedback controller for position control of synchronous reluctance motor," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 615-624, June 2001. Abstract Link Full Text Abstract: A new totally invariant state feedback controller is designed by combining the classical state feedback controller and the variable-structure control (VSC). The combination of these two different control methods has the advantages of both their merits: (1) the easy design of the state feedback and (2) the strong robustness of the VSC. In other words, the system performance can be simply designed for the nominal system by using the classical state feedback, which includes such well-known techniques as the pole placement or the linear quadratic method. Then, VSC is used to ensure the control effect. To demonstrate the effectiveness of the totally invariant state feedback controller, it is applied to the position control of a synchronous reluctance motor. Simulation results are first given. In addition, a prototype hardware system is built and experimentally evaluated
48.3.16	R. Cardenas, R. Pena, G. Asher, J. Clare, "Control strategies for enhanced power smoothing in wind energy systems using a flywheel driven by a vector-controlled induction machine ," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 625-635, June 2001. Abstract Link Full Text Abstract: This paper presents a novel control strategy for power smoothing in wind energy applications, especially those feeding a stand-alone load. The system is based on a vector-controlled induction machine driving a flywheel and addresses the problem of regulating the DC-link system voltage against both input power surges/sags from a wind turbine or sudden changes in load demand. The control is based on a feedforward compensation scheme augmented by a nonlinear controller. Two feedforward compensation schemes are discussed and the limitations and performance of each scheme are analyzed. Experimental results are presented which verify the excellent performance of the feedforward compensation technique
48.3.17	H. Fujimoto, Y. Hori, A. Kawamura, "Perfect tracking control based on multirate feedforward control with generalized sampling periods," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 636-644, June 2001. Abstract Link Full Text Abstract: In this paper, a novel perfect tracking control method based on multirate feedforward control is proposed. The advantages of the proposed method are that: (1) the proposed multirate feedforward controller eliminates the notorious unstable zero problem in designing the discrete-time inverse system; (2) the states of the plant match the desired trajectories at every sampling point of reference input; and (3) the proposed controller is completely independent of the feedback characteristics. Thus, highly robust performance is assured by the robust feedback controller. Moreover, by generalizing the relationship between the sampling period of plant output and the control period of plant input, the proposed method can be applied to various systems with hardware restrictions of these periods, which leads to higher performance. Next, it is shown that the structure of the proposed perfect tracking controller is very simple and clear. Illustrative examples of position control using a DC servomotor are presented, and simulations and experiments demonstrate the advantages of this approach
48.3.18	A. Balestrino, A. Landi, M. Ould-Zmirli, L. Sani, "Automatic nonlinear auto-tuning method for Hammerstein modeling of electrical drives," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 645-655, June 2001. Abstract Link Full Text Abstract: Accurate modeling of electrical drives for online testing is a relevant problem, because of their nonlinear behavior. Efficient modeling for simulation, performance evaluation, and testing must consider accurate as well as simple models. This paper proposes the application of auto-tune methods to identify equivalent Hammerstein models, where the nonlinear process is approximated by a static nonlinear element followed by a linear dynamic second or third-order model. The effectiveness of the presented procedure is first verified by simulation results, showing that Hammerstein models overcome the limitations inherent to small-signal linearizations. A standard implementation of such technique considers a relay adjustment for attempts in a heuristic way. In this paper, two innovations are proposed: the relay adjustment is automatically shifted and the method is applied for complex electric drives. Experimental results are shown in the case of a drive constituted by a DC/AC inverter supplying a single-phase induction motor and of a step-down chopper
48.3.19	Teck-Seng Low, Shixin Chen, Xianke Gao, "Robust torque optimization for BLDC spindle motors," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 656-663, June 2001. Abstract Link Full Text Abstract: A robust design for torque optimization of brushless DC spindle motors applied in a hard disk drive, using the Taguchi method, is described and illustrated in this paper. The optimal design process takes into consideration noises that arise in the manufacturing process, such as manufacturing tolerances for the stator tooth shape and variation of the rotor magnet magnetization distribution due to the magnetization fixture and process. The objective of the optimal design using the combined Taguchi's design of experiment (DOE) and finite-element analysis (FEA) approach is to ensure that the spindle motor torque performance is insensitive to the noise, with moderate computational effort. The optimization is realized by a simulation and analysis tool that integrates Taguchi's DOE with the FEA. In this paper, the design optimization process is described and the results are presented
48.3.20	I. Agirman, A.M. Stankovic, G. Tadmor, H. Lev-Ari, "Adaptive torque-ripple minimization in switched reluctance motors ," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 664-672, June 2001. Abstract Link Full Text Abstract: This paper addresses torque-ripple reduction in current-fed switched reluctance motors (SRMs). Ripple-free torque production in SRMs requires an accurate model that is often too complex for practical implementation. The algorithm proposed here combines the use of a simplified model with adaptation. Explicitly, it includes dynamic estimation of low harmonics of the combined unknown load torque and the ripple in the produced torque (due to model simplification), and adds appropriate terms to the commanded current to cancel these harmonics. Several simulations are presented first, suggesting that our method is effective for constant-speed reference commands, even when a very simple model is used in control design. Experimental results are included next to demonstrate that the algorithm performs well in reducing the torque ripple. Finally, limitations of the adaptive algorithm are explored and quantified
48.3.21	R.C. Kavanagh, "Probabilistic learning technique for improved accuracy of sinusoidal encoders," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 673-681, June 2001. Abstract Link Full Text Abstract: Sinusoidal-encoder-based digital tachometers are often limited by nonidealities in both encoder construction and interface electronics. A probabilistically based compensation technique is presented which dispenses with the need for specialized calibration equipment. A code-density array, obtained during a learning phase, is utilized to yield a compensation function which approximates to the average relationship over the mechanical cycle between the calculated electrical angle (as determined by an arctangent-based algorithm) and the actual angle. An extended version of this probabilistically compensated sinusoidal encoder technique is used to compensate for variations in the encoder characteristics as it rotates through a mechanical cycle. An analysis of the learning-time requirements of the system is presented. Practical results, utilizing performance measures common in the testing of analog-to-digital converters, confirm the utility of the method. An example of the benefits which accrue from the inclusion of the enhanced sensor in closed-loop systems is also provided Robotics and Vision
48.3.22	S. Grgic, M. Grgic, B. Zovko-Cihlar, "Performance analysis of image compression using wavelets," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 682-695, June 2001. Abstract Link Full Text Abstract: The aim of this paper is to examine a set of wavelet functions (wavelets) for implementation in a still image compression system and to highlight the benefit of this transform relating to today's methods. The paper discusses important features of wavelet transform in compression of still images, including the extent to which the quality of image is degraded by the process of wavelet compression and decompression. Image quality is measured objectively, using peak signal-to-noise ratio or picture quality scale, and subjectively, using perceived image quality. The effects of different wavelet functions, image contents and compression ratios are assessed. A comparison with a discrete-cosine-transform-based compression system is given. Our results provide a good reference for application developers to choose a good wavelet compression system for their application
48.3.23	S. Segvic, S. Ribaric, "Determining the absolute orientation in a corridor using projective geometry and active vision," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 696-710, June 2001. Abstract Link Full Text Abstract: The capability of a mobile robot to determine its position in the environment (self-localization) is a prerequisite for achieving autonomous navigation. An approach is proposed for determining the absolute orientation of an autonomous robot in a system of corridors, based on the projective geometry and active computer vision. In the proposed approach, the common direction of longitudinal corridor edges is inferred by detecting the vanishing point of the corresponding straight line segments in the image. It is assumed that the knowledge about the vertical direction in the scene is available, so that the image coordinates of these vanishing points are considerably constrained. However, longitudinal corridor edges are not visible in images acquired for many viewing directions, so that the processing in a localization procedure has to be performed on a sequence of images acquired from the given position, for regularly arranged orientations of the camera. Extensive experimentation was performed on real scenes and the obtained results are provided Letters to the Editor
48.3.24	M. Rodrigues, P.J. Costa Branco, W. Suemitsu, "Fuzzy logic torque ripple reduction by turn-off angle compensation for switched reluctance motors," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 711-715, June 2001. Abstract Link Full Text Abstract: A fuzzy-logic-based turn-off angle compensator for torque ripple reduction in a switched reluctance motor is proposed. The turn-off angle, as a complex function of motor speed and current, is automatically changed for a wide motor speed range to reduce torque ripple. Experimental results are presented that show ripple reduction when the turn-off angle compensator is used
48.3.25	E. Monmasson, A.A. Naassani, J.-P. Louis, "Extension of the DTC concept," IEEE Trans. on Industrial Electronics, vol. 48, no. 3, pp. 715-717, June 2001. Abstract Link Full Text Abstract: The authors propose to extend the direct torque control (DTC) concept. This extension concerns voltage-vector generation. Based on this, it is possible to generate any voltage vector by the space-vector modulation method and apply DTC strategy at the same time. Experimental results are carried out to validate the proposed approach