IEEE Transactions on Industrial Electronics

Volume 55, Number 4, April 2008 Access to the journal on IEEE XPLORE IE Transactions Home Page

Special Section Papers

55.4.1	"Table of Contents," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. C1-1498, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.2	"IEEE Transactions on Industrial Electronics publication information," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. C2-C2, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.3	E. Monmasson, M. N. Cirstea, "Guest Editorial," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1499-1500, April 2008. Abstract Link Full Text Abstract: The seven papers in the second part of this special section focus on field programmable gate arrays (FPGAs) used in industrial control systems. Five refer to power converter control applications and the other two are focused on control and robotic applications. The papers are summarized here.
55.4.4	L. Corradini, P. Mattavelli, E. Tedeschi, D. Trevisan, "High-Bandwidth Multisampled Digitally Controlled DC–DC Converters Using Ripple Compensation," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1501-1508, April 2008. Abstract Link Full Text Abstract: This paper investigates multi sampled digitally controlled switched-mode power supplies with switching ripple compensation. In digital controllers for power converters, the main bandwidth limitations come from A/D conversion time, computational delays, and small-signal delay of the digital pulsewidth modulator (DPWM). In hard-wired digital-controller technologies, such as in dedicated digital IC and/or in field-programmable gate arrays (FPGAs), the calculation delays can be made negligible with respect to the switching period; thus, when fast ADCs are used, the overall phase lag is dominated by the DPWM. The multi sampling approach can strongly reduce the DPWM delay, thus breaking the bandwidth limitations of conventional single-sampled solutions. In this paper, the additional aliasing effects, which would require a filtering action, are avoided, exploiting the periodic nature of the switching ripple under steady-state conditions using a repetitive-based filtering action. Simulation and experimental results on a 1.2-V-10-A 500-kHz synchronous buck converter, where the digital control has been implemented in the FPGA, confirm the properties of the proposed solution.
55.4.5	W. Stefanutti, S. Saggini, P. Mattavelli, M. Ghioni, "Power Line Communication in Digitally Controlled DC–DC Converters Using Switching Frequency Modulation," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1509-1518, April 2008. Abstract Link Full Text Abstract: This paper investigates power line communication (PLC) in digitally controlled high-frequency switched-mode power supplies in distributed architectures that share the same bus voltage. Communication between different DC-DC converters is obtained by using switching frequency modulation and by detecting the switching signal on the common supply bus voltage. In case of low power transmission, a small duty-cycle perturbation at half of switching frequency is added to enhance the energy of the transmitted signal. Each converter operates at three different switching frequencies: the first is associated with bit 1 transmission, the second is associated with bit 0 transmission, and the third is associated with no transmission state. In the proposed solution, there is no need for an additional power amplifier in order to inject the communication signal on the power lines, but the signal used for the PLC is inherently generated by the pulsewidth modulation of DC-DC converters. Even if aimed at a dedicated digital IC, the communication architecture has been implemented in field-programmable gate arrays. Simulation and experimental results on DC-DC synchronous buck converters confirm that the performance is achievable by the proposed PLC techniques.
55.4.6	F. Iannuzzo, "Race-Control Algorithm for the Full-Bridge PRCP Converter Using Cost-Effective FPGAs," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1519-1526, April 2008. Abstract Link Full Text Abstract: In this paper, the unedited race-control algorithm (RCA) for the full-bridge passive resonant commutated poles (FB-PRCP) converter is presented and implemented with a field-programmable gate-array technique. It compensates the drawbacks of that topology that are related to the slow dynamics of the auxiliary poles which are necessary to obtain zero-voltage transitions both at turn-on and turn-off conditions and makes possible its use in more general welding applications, such as manual metal arc welding, in which very fast responses are required. The proposed RCA is a simple variation of the traditional phase-shift technique, which leads to significant efficiency improvements. The guiding idea is to apply the phase-shift technique to both legs of the converter, contrarily to what has been done to date. Leg B is delayed when phase shift must be increased, whereas leg A is delayed when a phase-shift reduction is needed, contrarily to the traditional phase-shift technique, where Leg B is delayed or anticipated and Leg A is held at a fixed phase. In this way, the limitation in dynamics of the converter is completely eliminated and it gains much more readiness. The effectiveness of the RCA has been experimentally tested on a true converter.
55.4.7	Zeliang Shu, Yuhua Guo, Jisan Lian, "Steady-State and Dynamic Study of Active Power Filter With Efficient FPGA-Based Control Algorithm," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1527-1536, April 2008. Abstract Link Full Text Abstract: A new approach using field-programmable gate array (FPGA) to implement a fully digital control algorithm of active power filter (APF) is proposed in this paper. This FPGA-based controller integrates the whole signal-processing function of an APF, including synchronous-reference-frame transform, low-pass filter, three-phase phase-locked loop, inverter-current controller, etc. By case studies on the principle, performance, and architecture, these control blocks are implemented in real-time and synthesized into a medium-scale FPGA chip by adopting some useful digital-signal-processing techniques, such as pipelining, folding and strength reduction, with respect to minimization of hardware resource and enhancement of operating frequency. As a result, the whole algorithm needs around 5000 logic elements and can run at synchronous system-clock rates of up to 65 MHz. Experimental results on a laboratory prototype are given to demonstrate performance of the proposed approach during steady-state and dynamic operations.
55.4.8	O. Lopez, J. Alvarez, J. Doval-Gandoy, F.D. Freijedo, A. Nogueiras, A. Lago, C.M. Penalver, "Comparison of the FPGA Implementation of Two Multilevel Space Vector PWM Algorithms," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1537-1547, April 2008. Abstract Link Full Text Abstract: Multilevel converters can meet the increasing demand of power ratings and power quality associated with reduced harmonic distortion and lower electromagnetic interference. When the number of levels increases, it is necessary to control more and more switches in parallel. Field programmable gate arrays (FPGAs), with their concurrent processing capability, are suitable for the implementation of multilevel modulation algorithms. Among them, space vector pulsewidth modulation algorithms offer great flexibility to optimize switching waveforms and are well suited for digital implementation. In this paper, two algorithms, 2-D and 3-D, are analyzed and implemented in an FPGA. In order to carry out the implementation, both algorithms have been described in very high speed integrated circuit hardware description language, partly hand coded, and partly automatically generated using the system generator tool. Both implementations are compared in terms of implementation complexity and logic resources required. Finally, test results with a neutral-point-clamped inverter are presented.
55.4.9	Tianjian Li, Y. Fujimoto, "Control System With High-Speed and Real-Time Communication Links," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1548-1557, April 2008. Abstract Link Full Text Abstract: Recent technological advances have enabled distributed control systems to be implemented via networks. This allows feedback control loops to be closed over communication channels. This paper develops a control system with high-speed and real-time communication links. Two-degrees-of-freedom control is utilized in this servo control system, and sigma-delta modulation is employed to compress data and to transmit the signal over the transmission channels between the controller and the controlled plant. Simulation results show that the controller can compensate the possible existing noise in the transmission channels. In addition, the developed system is implemented in field-programmable gate arrays. We developed a real-time closed-loop control system that has a communication channel whose control-sampling period is 600 ns and can reduce the sampling period of the controller module to hundreds of nanoseconds.
55.4.10	L. Vachhani, K. Sridharan, "Hardware-Efficient Prediction-Correction-Based Generalized-Voronoi-Diagram Construction and FPGA Implementation," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1558-1569, April 2008. Abstract Link Full Text Abstract: Sensor-based construction of different geometric structures has been an important development in the domain of autonomous robot navigation. This paper presents a hardware-efficient scheme to construct one such geometric structure, namely, the generalized Voronoi diagram (GVD), using a prediction-and- correction strategy. In this paper, an architecture to construct the GVD for an indoor environment with multiple obstacles whose geometry and location are not known beforehand is presented. A feature of the proposed approach is that it does not involve operations that are expensive in hardware. Furthermore, no explicit angle computation circuitry is needed. An efficient architecture based on hardware reuse is presented. The design is shown to be space efficient and fits in a low-end field-programmable gate-array (FPGA) device (with a small number of system gates). Detailed experiments with a mobile robot fabricated locally with a Xilinx XC2S200E FPGA and eight ultrasonic sensors onboard validate the efficacy of the proposed approach for static as well as dynamic environments. Single-Phase Electronics
55.4.11	Po-Yuan Chen, M. Jinno, Yu-Min Shie, "Research on the Reverse Conduction of Synchronous Rectifiers," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1570-1575, April 2008. Abstract Link Full Text Abstract: Research on the reverse current phenomenon in synchronous rectifiers (SRs) is presented in this paper. For loss reduction, the SRs composed of metal-oxide-semiconductor field-effect transistors (MOSFETs) have recently been employed to replace the conventional rectifiers with diodes in low-voltage and high-current applications. Because the MOSFETs in the SRs are used as bidirectional switches, reverse current flow will probably occur. The reverse current phenomenon will cause undesired power loss. To clarify the effects of the reverse current on the forward converter with an SR, both the experiment and the analysis are performed. Furthermore, the concepts and methods for dealing with this phenomenon are clearly described in this paper.
55.4.12	Bor-Ren Lin, Chien-Lan Huang, "Interleaved ZVS Converter With Ripple-Current Cancellation," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1576-1585, April 2008. Abstract Link Full Text Abstract: In this paper, an interleaved soft-switching converter with ripple-current cancellation is presented to achieve zero- voltage-switching (ZVS) turn-on and load current sharing. In order to achieve ZVS turn-on, an active snubber is connected in parallel with the primary winding of the transformer. The energy stored in the transformer leakage inductance and magnetizing inductance can be recovered so that the peak voltage stress of switching devices is limited. The resonance at the transition interval is used to realize ZVS turn-on of all switches. In order to achieve three-level pulsewidth-modulation (PWM) scheme, an addition fast-recovery diode is used in the converter. Three-level PWM scheme can reduce the ac ripple current on the output inductor such that the output inductor can be reduced. The current-doubler rectifier is adopted in the secondary side of the transformer to reduce the transformer secondary-winding current and output voltage ripple by canceling the current ripple of two output inductors. The output voltage is controlled at the desired value using the interleaved PWM scheme. These features make the proposed converter suitable for the dc-dc converter with high output current. The operation principles, steady state analysis, and design equations of the proposed converter are provided in detail. Finally, experiments based on a 600-W (12 V/50 A) prototype are provided to verify the effectiveness and feasibility of the proposed converter.
55.4.13	Bor-Ren Lin, Chien-Lan Huang, Jin-Fa Wan, "Analysis, Design, and Implementation of a Parallel ZVS Converter," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1586-1594, April 2008. Abstract Link Full Text Abstract: A soft-switching converter is presented in this paper to achieve a zero-voltage-switching (ZVS) turn on for all switches. Two half-bridge converters with asymmetric pulsewidth-modulation scheme are connected in parallel to control the output voltage at the desired value and achieve load-current sharing. Based on the output capacitance of power switches and the resonant inductance, including the external inductance and the transformer leakage inductance, the resonance can be achieved at the transition interval of power switches. Therefore, the ZVS turn on of power switches can be realized. The peak voltage of the power switches is limited to input dc voltage. The center-tapped rectifier is adopted at the transformer secondary side to achieve a full-wave rectification. Operation principles, steady-state analysis, and design equations of the proposed converter are discussed in detail. Finally, experimental results based on a 240-W prototype are provided to verify the performance and the feasibility of the proposed converter.
55.4.14	Bin Zhang, Danwei Wang, Keliang Zhou, Yigang Wang, "Linear Phase Lead Compensation Repetitive Control of a CVCF PWM Inverter," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1595-1602, April 2008. Abstract Link Full Text Abstract: This paper presents a simple and efficient linear phase lead compensation repetitive control scheme for engineers to develop high-performance power converter systems. The linear phase lead compensation helps a repetitive controller to achieve faster convergence rate, higher tracking accuracy, and wider stability region. In the proposed scheme, the phase lead compensation repetitive controller is plugged into generic state-feedback-controlled converter systems. Its comprehensive synthesis, which involves principle, analysis, design, modeling, implementation, and experiments, is systematically and completely presented in great detail. A complete series of experiments is successfully carried out to verify the solution. Multiphase Systems
55.4.15	Li-Chun Liao, Ching-Tsai Pan, Tai-Lang Jong, "Switching Flow-Graph Modeling Technique for Three-Phase Inverters," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1603-1613, April 2008. Abstract Link Full Text Abstract: In this paper, a unified graphical modeling technique is developed for investigating the behavior of pulsewidth- modulated three-phase inverters. By introducing the virtual- switch concept together with its virtual switching function, it is seen that the existing attractive switching flow-graph modeling technique for dc-to-dc converters can be extended to three-phase inverters without losing its merits. The corresponding large- signal, steady-state, and small-signal models can then be also obtained easily. Some examples, implemented easily with MATLAB/ Simulink, are also given to demonstrate the feasibility of the proposed technique.
55.4.16	G. Narayanan, V.T. Ranganathan, D. Zhao, H.K. Krishnamurthy, R. Ayyanar, "Space Vector Based Hybrid PWM Techniques for Reduced Current Ripple," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1614-1627, April 2008. Abstract Link Full Text Abstract: This paper investigates certain novel switching sequences involving division of active vector time for space vector based pulsewidth modulation (PWM) generation for a voltage source inverter. This paper proposes two new sequences, and identifies all possible sequences, which result in the same average switching frequency as conventional space vector PWM (CSVPWM) at a given sampling frequency. This paper brings out a method for designing hybrid PWM techniques involving multiple sequences to reduce line current ripple. The three proposed hybrid PWM techniques (three-zone PWM, five-zone PWM and seven zone PWM) employ three, five and seven different sequences, respectively, in every sector. Each sequence is employed in a spatial region within the sector where it results in the lowest rms current ripple over the given sampling period. The proposed techniques lead to a significant reduction in THD over CSVPWM at high line voltages. The five-zone technique results in the lowest THD among real-time techniques with uniform sampling, while the seven-zone technique is the best among real-time techniques with twin sampling rates. The superior harmonic performance of the proposed techniques over CSVPWM and existing bus-clamping PWM techniques is established theoretically as well as experimentally.
55.4.17	D.O. Neacsu, E. Wagner, B.S. Borowy, "A Simulation Benchmark for Selection of the PWM Algorithms for Three-Phase Interleaved Converters," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1628-1636, April 2008. Abstract Link Full Text Abstract: A solution for high current applications consists of paralleling power stages of lower power. Given the complexity of these systems, a comprehensive computer-based analysis is required before physical implementation. This paper presents a simulation benchmark for selection of the pulsewidth modulation (PWM) algorithms used to control interleaved three-and four-wire three-phase power inverters. The analysis considers the resulting phase current harmonics, dc link current harmonics, neutral point voltage, and inter converter circulation currents. Analytical aspects of different current control structures used within interleaved power electronics systems and effects of selecting various PWM algorithms are revealed for both the three-wire and the four-wire structure. Finally, analysis of the DSP implementation for different practical solutions is shown.
55.4.18	H.M. Suryawanshi, A.K. Kulwal, M.A. Chaudhari, V.B. Borghate, "High Power Factor Operation of a Three-Phase Rectifier for an Adjustable-Speed Drive," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1637-1646, April 2008. Abstract Link Full Text Abstract: This paper presents a novel approach to improve the power factor (PF) and reduce the harmonics generated by an adjustable-speed drive (ASD). A high-frequency (HF) current injection technique is used to improve the PF and harmonic performance. The HF current at the same switching frequency (33 kHz) is injected into the input of a front-end rectifier from the output of an HF inverter. The main feature of the circuit is that it does not require any additional active devices for current injection. The inverter driving the induction motor is operated using a sinusoidal pulsewidth-modulation technique. The circuit simulation and experimental prototype results are presented for 67-hp (50 kW) and 3-hp three-phase induction motors, respectively.
55.4.19	S. Vazquez, J.A. Sanchez, J.M. Carrasco, J.I. Leon, E. Galvan, "A Model-Based Direct Power Control for Three-Phase Power Converters," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1647-1657, April 2008. Abstract Link Full Text Abstract: The direct power control (DPC) technique has been widely used as a control strategy for three-phase power rectifiers due to its simplicity and good performance. DPC uses the instantaneous active and reactive power to control the power converter. The controller design has been proposed as a direct control with a lookup table and, in recent works, as an indirect control with an inner control loop with proportional-plus-integral controllers for the instantaneous active and reactive power errors. In this paper, a model-based DPC for three-phase power converters is designed, obtaining expressions for the input control signal, which allow the design of an adaptive control law that minimizes the errors introduced by parameter uncertainties as the smoothing inductor value or the grid frequency. A controller design process, a stability study of the system, and experimental results for a synchronous three-phase power rectifier prototype are presented to validate the proposed controller.
55.4.20	Juanjuan Wang, Chuang Fu, Yao Zhang, "SVC Control System Based on Instantaneous Reactive Power Theory and Fuzzy PID," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1658-1665, April 2008. Abstract Link Full Text Abstract: Industrial static VAr compensators (SVCs) are typically applied at or near the load center to mitigate voltage fluctuations, flicker, phase unbalance, or other load-related disturbances. In this paper, a phase-to-phase "open + close" control scheme for industrial SVC is proposed. The forward loop is to guarantee short response time, while the feedback loop is to ensure good dynamics and steady characteristics of SVC. The fast compensation algorithm for asymmetric industrial loads based on instantaneous reactive power theory is used in the forward loop, while a fuzzy proportional-integral-differential control strategy is applied to the close loop. The hardware and software of this SVC control system is developed based on SIMATIC-TDC and WinCC; the former is the most modern but well-proven industrial controller, while the latter is the globally used human machine interface system. Many industrial applications show that this kind of control system can meet the strict performance and reliability requirements of industrial SVCs.
55.4.21	N. Bel Haj Youssef, K. Al-Haddad, H.Y. Kanaan, "Implementation of a New Linear Control Technique Based on Experimentally Validated Small-Signal Model of Three-Phase Three-Level Boost-Type Vienna Rectifier," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1666-1676, April 2008. Abstract Link Full Text Abstract: In this paper, the design and implementation of a new multiple-input-multiple-output linear control technique based on a theoretically established and experimentally validated small- signal model for the three-phase three-level boost-type ac/dc Vienna converter are presented. Averaging and local linearization techniques are used to derive the dynamic model expressed in the dqo reference frame. The resulted transfer functions are discretized for the sake of a digital controller design. Multiple-loop control strategy is adopted and consists of inner current feedback loops, which are based on the straightforward looping technique that neglects interactions between the dq components of control inputs and currents, respectively, and of an outer voltage loop, which is designed to ensure dc voltage regulation by adjusting the magnitude of the references for the inner current loops. The output dc voltage unbalance is also controlled in the inner loops. The proposed modeling and control approaches are first simulated and then validated on a 1.5-kW laboratory prototype supported by the DS 1104 digital real-time controller board of dSPACE. The obtained results prove the accuracy of the proposed new small-signal model and, therefore, its reliability for dynamic analysis and control design purposes. It is also proved that a judicious choice of controller parameters, as well as an adequate rating of boost inductors, allows one to meet the IEEE standard requirements in terms of ac line-current total harmonic distortion and power factor. The efficiency of the proposed control technique is maintained in case of disturbances occurring on both source and load sides. Renewable Energy Systems
55.4.22	Seul-Ki Kim, Jin-Hong Jeon, Chang-Hee Cho, Jong-Bo Ahn, Sae-Hyuk Kwon, "Dynamic Modeling and Control of a Grid-Connected Hybrid Generation System With Versatile Power Transfer," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1677-1688, April 2008. Abstract Link Full Text Abstract: This paper presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. The hybrid system is the combination of photovoltaic (PV) array, wind turbine, and battery storage via a common dc bus. Versatile power transfer was defined as multimodes of operation, including normal operation without use of battery, power dispatching, and power averaging, which enables grid- or user-friendly operation. A supervisory control regulates power generation of the individual components so as to enable the hybrid system to operate in the proposed modes of operation. The concept and principle of the hybrid system and its control were described. A simple technique using a low-pass filter was introduced for power averaging. A modified hysteresis-control strategy was applied in the battery converter. Modeling and simulations were based on an electromagnetic-transient-analysis program. A 30-kW hybrid inverter and its control system were developed. The simulation and experimental results were presented to evaluate the dynamic performance of the hybrid system under the proposed modes of operation.
55.4.23	H. Patel, V. Agarwal, "Maximum Power Point Tracking Scheme for PV Systems Operating Under Partially Shaded Conditions," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1689-1698, April 2008. Abstract Link Full Text Abstract: Current-voltage and power-voltage characteristics of large photovoltaic (PV) arrays under partially shaded conditions are characterized by multiple steps and peaks. This makes the tracking of the actual maximum power point (MPP) [global peak (GP)] a difficult task. In addition, most of the existing schemes are unable to extract maximum power from the PV array under these conditions. This paper proposes a novel algorithm to track the global power peak under partially shaded conditions. The formulation of the algorithm is based on several critical observations made out of an extensive study of the PV characteristics and the behavior of the global and local peaks under partially shaded conditions. The proposed algorithm works in conjunction with a DC-DC converter to track the GP. In order to accelerate the tracking speed, a feedforward control scheme for operating the DC-DC converter is also proposed, which uses the reference voltage information from the tracking algorithm to shift the operation toward the MPP. The tracking time with this controller is about one-tenth as compared to a conventional controller. All the observations and conclusions, including simulation and experimental results, are presented. Robotics and Mechatronics
55.4.24	S. Katsura, K. Irie, K. Ohishi, "Wideband Force Control by Position-Acceleration Integrated Disturbance Observer," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1699-1706, April 2008. Abstract Link Full Text Abstract: Motion control is widely used in industry applications. One of its key components is the disturbance observer, which estimates a disturbance torque of a motion system and realizes a robust acceleration control. A disturbance observer observes and suppresses the disturbance torque within its bandwidth. Motion systems have started to spread in society and they are required to have the ability to interact with unknown environments. Such a haptic motion requires much wider bandwidth. However, since the conventional disturbance observer attains the acceleration information by the second-order derivative of a position response, the bandwidth is limited due to the derivative noise. To enlarge the bandwidth of a disturbance observer, this paper proposes a position-acceleration integrated disturbance observer (PAIDO). Since an acceleration sensor is implemented in it, the control performance of the PAIDO is superior to the conventional one. In this paper, the PAIDO is applied to force control and the viability of the proposed method is confirmed by fast Fourier transformation analyses. The experimental results show the viability of the proposed method.
55.4.25	K. Nakano, T. Murakami, "An Approach to Guidance Motion by Gait-Training Equipment in Semipassive Walking," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1707-1714, April 2008. Abstract Link Full Text Abstract: Recently, population aging and declining birth rate have become very serious, and people who lack walking capability have truly increased in Japan. To address this issue, gait training has become a requirement for them. Although some training systems have been researched in the past, a training system that entails guidance of walking has not been researched well. This paper focuses on guidance of walking, and it is aimed to develop a training system that utilizes the activity and passivity of the trainee. In addition, rhythmic walking, which takes walking stability and trainee safety into account, is aimed for. In this paper, an improved electric wheelchair is used as gait-training equipment (GTE); then, the trainee is towed by the GTE, and walking is guided. In this paper, a targeted walking cycle is predefined, and the GTE must distinguish the cycle in order to guide walking. Therefore, this paper uses the center of gravity (COG) of the trainee as the index. Thus, the GTE tows the trainee when the swing leg moves more forward than the stance leg; then, rhythmic walking can be guided. In addition, this paper proposes a method to control the GTE by a proportional-differential controller based on virtual compliance that is composed of mass, spring, and damper. The gait training can be safely achieved by deciding the desired position and velocity of the GTE from the tow force through virtual compliance. In this paper, the validity of the proposed method is verified by numerical simulation and experiment. The validity of the proposed system is verified by using a four-link robot whose geometric expression is known as the trainee; then, the application of the proposed method will be extended to a human trainee by only adjusting the parameters.
55.4.26	S. Tashiro, T. Murakami, "Step Passage Control of a Power-Assisted Wheelchair for a Caregiver," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1715-1721, April 2008. Abstract Link Full Text Abstract: Various welfare devices have been developed by the influence of the population's aging society. They are required to support caregivers and cared-for people these days because the burden of the nursing care is increasing. A method to realize a caregiver's power-assist control for an electric wheelchair is proposed in this paper. This method enables power-assisted wheelchairs to adapt not only to flat roads but also to roads with steps. Instead of a force sensor, a reaction torque estimation observer is constructed to detect the human torque input into the wheelchair. An inclination sensor is used to detect the step and to determine the control method while passing over the step. Simulations and experiments were carried out to show the validity of the proposed method. Motors and Actuators
55.4.27	Z. Gmyrek, A. Boglietti, A. Cavagnino, "Iron Loss Prediction With PWM Supply Using Low- and High-Frequency Measurements: Analysis and Results Comparison," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1722-1728, April 2008. Abstract Link Full Text Abstract: In this paper, two different methods for iron loss prediction are analyzed. The first method is based on the classical separation of loss contributions (hysteresis, eddy-current, and excess losses). The model requires loss contribution separation using iron loss measurements with sinusoidal supply. In this paper, this method will be called the ldquolow-frequency method.rdquo The second method, named the ldquohigh-frequency method,rdquo is based on the assumption that, under pulsewidth modulation supply, the higher order flux density harmonics do not influence the magnetic work conditions. These magnetic conditions depend only on the amplitude of the fundamental harmonic of the flux density. In this paper, both the proposed methodologies and the related measurements are described in detail, and the obtained results are compared with the experimental ones. The experimental results show that both methods allow getting excellent results. The high-frequency method is better than the lower one but requires a more complex test bench. Depending on the accuracy required by the user, the more handy method can be chosen, with the guarantee that the estimation errors will be lower than 5%.
55.4.28	Hsin-Jang Shieh, Chia-Hsiang Hsu, "An Adaptive Approximator-Based Backstepping Control Approach for Piezoactuator-Driven Stages," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1729-1738, April 2008. Abstract Link Full Text Abstract: This paper investigates precise trajectory tracking of a piezoactuator-driven stage with hysteresis behavior by using an approximator-based adaptive tracking control approach. Differential equations consisting of the dynamics of a linear motion system and a hysteresis function are first studied for describing the dynamics of motion of the piezoactuator-driven stage with hysteresis behavior. Then, a numerical optimization method is taken to identify the values of the parameters adopted in the differential equations. From the differential equations, an equivalent state-space model with an augmented integral input and with a defined hysteresis variable is established. Moreover, to approximate the unavailable hysteresis variable, an adaptive approximator that comprises a Gaussian radial-basis function network is adopted. Furthermore, from the state-space model, an adaptive approximator-based backstepping trajectory-tracking control is developed. Using the proposed control approach to trajectory tracking of the piezoactuator-driven stage, an improvement in transient performance and tracking errors, and robustness to the disturbance load, can be provided. Last, to show the validity of the proposed control approach, an implementation of the control algorithm on the computer-controlled single-axis piezoactuator-driven stage was developed. From the experimental results, the feasibility of the proposed control for practical applications can be confirmed.
55.4.29	Wenxiang Zhao, Ming Cheng, Xiaoyong Zhu, Wei Hua, Xiangxin Kong, "Analysis of Fault-Tolerant Performance of a Doubly Salient Permanent-Magnet Motor Drive Using Transient Cosimulation Method," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1739-1748, April 2008. Abstract Link Full Text Abstract: Doubly salient permanent-magnet (DSPM) motors offer the advantages of high power density and high efficiency. In this paper, it is examined that the DSPM motor is a new class of fault-tolerant machines, a potential candidate for many applications where reliability and power density are of importance. Fault analysis is performed in a DSPM motor drive, including internal and external faults. Due to the fact that the experimentation on a true motor drive for such a purpose is impractical because of its high cost and difficulty to make, a new cosimulation model of a DSPM motor drive is developed using coupled magnetic and electric circuit solvers. Last, to improve the performance of a DSPM motor drive with an open-circuited fault, a fault compensation strategy is proposed. Simulation and experimental results are presented, showing the effectiveness of the proposed cosimulation method and the high performance of the fault-tolerant characteristic of DSPM motor drives. Drive Control
55.4.30	G. Buja, R. Menis, "Steady-State Performance Degradation of a DTC IM Drive Under Parameter and Transduction Errors," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1749-1760, April 2008. Abstract Link Full Text Abstract: With direct torque control (DTC), the stator flux magnitude and the torque of an induction motor (IM) drive are controlled in a closed-loop way. The actual values of the controlled variables are estimated by processing the inverter dc-link voltage and the stator currents by means of the IM voltage model. Any error in the model parameter (the stator resistance) or in the voltage and current transduction degrades the drive performance. In this paper, a theoretical investigation of the effects of the various errors on a DTC IM drive is carried out. The investigation gives a proof of the drive instability due to some errors and provides, for the other errors, the amount of the deviation produced on the controlled variables in steady state. The theoretical findings are substantiated by experimental and simulation results.
55.4.31	Zhong Du, L.M. Tolbert, J.N. Chiasson, B. Ozpineci, "Reduced Switching-Frequency Active Harmonic Elimination for Multilevel Converters," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1761-1770, April 2008. Abstract Link Full Text Abstract: This paper presents a reduced switching-frequency active-harmonic-elimination method (RAHEM) to eliminate any number of specific order harmonics of multilevel converters. First, resultant theory is applied to transcendental equations to eliminate low-order harmonics and to determine switching angles for a fundamental frequency-switching scheme. Next, based on the number of harmonics to be eliminated, Newton climbing method is applied to transcendental equations to eliminate high-order harmonics and to determine switching angles for the fundamental frequency-switching scheme. Third, the magnitudes and phases of the residual lower order harmonics are computed, generated, and subtracted from the original voltage waveform to eliminate these low-order harmonics. Compared to the active-harmonic-elimination method (AHEM), which generates square waves to cancel high-order harmonics, RAHEM has lower switching frequency. The simulation results show that the method can effectively eliminate all the specific harmonics, and a low total harmonic distortion (THD) near sine wave is produced. An experimental 11-level H-bridge multilevel converter with a field-programmable gate-array controller is employed to experimentally validate the method. The experimental results show that RAHEM does effectively eliminate any number of specific harmonics, and the output voltage waveform has low switching frequency and low THD.
55.4.32	E.P. Wiechmann, P. Aqueveque, R. Burgos, J. Rodriguez, "On the Efficiency of Voltage Source and Current Source Inverters for High-Power Drives," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1771-1782, April 2008. Abstract Link Full Text Abstract: The energy performance of various types of voltage-source and current-source converters is examined. For fairness and completeness, efficiency is calculated for three major battleground scenarios. The first is a low dynamic nonregenerative group of applications such as pumps, fans, and compressors. This group represents 85% of high power (2 MW) industrial applications where energy savings are usually a primary consideration justifying investment. The second scenario considers applications requiring good dynamic response and regenerative braking. Finally, the third group considers very high power applications (over 20 MW). The evaluation presented takes into account semiconductor switching and conduction losses, losses in the medium voltage feeding transformer (determined per IEEE Standard C57.18.10-1998), and the losses in ac and dc filters. For purposes of analysis, computer simulations validated against measurements taken on a 1-MW voltage source inverter (VSI) and a 1.4-MW current source inverter (CSI) were used. The results of the first scenario show competitive efficiencies for VSI and CSI drives, whereas voltage source-based solutions are more energy efficient in the second scenario considered. For the last group, the current source load-commutated inverter exhibits the best performance.
55.4.33	H.A. Toliyat, M. Wlas, Z. Krzemiriski, "Neural-Network-Based Parameter Estimations of Induction Motors," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1783-1794, April 2008. Abstract Link Full Text Abstract: The goal of this paper is to use artificial neural networks (ANNs) for online identification of induction-motor parameters. ANNs such as feedforward and recurrent networks will be used to develop an ANN as a memory for remembering the estimated parameters and for computing the parameters during transients. Simulations and experimental results will be presented for a nonlinear control system of induction motors. A digital signal processor will be used for the experimental investigation. Signal Processing and Control
55.4.34	K. Acharya, S.K. Mazumder, I. Basu, "Reaching Criterion of a Three-Phase Voltage-Source Inverter Operating With Passive and Nonlinear Loads and Its Impact on Global Stability," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1795-1812, April 2008. Abstract Link Full Text Abstract: We develop and demonstrate a technique based on composite Lyapunov functions (CLFs) to analyze the impacts of passive (RL and RC) and nonlinear (diode rectifier) loads on the reaching dynamics of a three-phase voltage-source inverter (VSI). The reaching criterion (which ensures convergences of state trajectories to an orbit) is synthesized using piecewise linear models of the VSI and the loads and conditions for switching among the various models (corresponding to the different switching states). Once orbital existence is ensured using the reaching criterion , we extend the CLF-based approach to predict the stability of the nominal (period-1) orbit of the system (comprising the three-phase VSI and the load) and compare these predictions with those obtained using a conventional impedance-criterion technique that is developed based on a linearized averaged model. Overall, we demonstrate the significance of analyzing the reaching condition from the standpoint of orbital existence and why such a criterion is necessary for analyzing global stability. On a broader note, the methodology outlined in this paper is useful for analyzing the global stability of multiphase inverters, potentially leading to advanced control design of VSI for applications including uninterrupted power supplies, telecommunication power supplies, grid-connected inverters, motor drives, and active filters. Motors and Actuators
55.4.35	M. Blodt, P. Granjon, B. Raison, G. Rostaing, "Models for Bearing Damage Detection in Induction Motors Using Stator Current Monitoring," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1813-1822, April 2008. Abstract Link Full Text Abstract: This paper describes a new analytical model for the influence of rolling-element bearing faults on induction motor stator current. Bearing problems are one major cause for drive failures. Their detection is possible by vibration monitoring of characteristic bearing frequencies. As it is possible to detect other machine faults by monitoring the stator current, a great interest exists in applying the same method for bearing fault detection. After a presentation of the existing fault model, a new detailed approach is proposed. It is based on the following two effects of a bearing fault: 1. the introduction of a particular radial rotor movement and 2. load torque variations caused by the bearing fault. The theoretical study results in new expressions for the stator current frequency content. Experimental tests with artificial and realistic bearing damage were conducted by measuring vibration, torque, and stator current. The obtained results by spectral analysis of the measured quantities validate the proposed theoretical approach. Embedded Systems
55.4.36	M.C. Di Piazza, G. Tine, G. Vitale, "An Improved Active Common-Mode Voltage Compensation Device for Induction Motor Drives," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1823-1834, April 2008. Abstract Link Full Text Abstract: This paper presents a new device for the compensation of common-mode (CM) disturbance in induction motor drives, based on the active cancellation approach. The detailed design and the experimental implementation issues of the new active compensation device for a 380-V/50-Hz pulsewidth-modulation (PWM) induction motor drive are discussed. Starting from the idea of the active common-noise canceller, the proposed active compensation device is suitably improved in order to overcome the limitations of similar previously proposed circuits. In fact, it can be successfully used within a drive system with a rated voltage of 380 V or higher by employing an improved active circuit with a dedicated dc power supply derived from the ac power supply line. In addition, the design follows the criteria of compactness and minimum cost. The performance of the realized active compensation device is verified through experimental measurements of the CM voltage, the CM current, and the motor shaft voltage. The effectiveness of the proposed solution is demonstrated by experimental results. Emerging Technology
55.4.37	Jin-Shyan Lee, "A Petri Net Design of Command Filters for Semiautonomous Mobile Sensor Networks," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1835-1841, April 2008. Abstract Link Full Text Abstract: In semiautonomous mobile sensor networks (MSNs), since human operators may be involved in the control loop, particular improper actions may cause accidents and result in catastrophes. For such systems, this paper proposes a command filtering framework to accept or reject the human-issued commands so that undesirable executions are never performed. In the present approach, Petri nets are used to model the operated behaviors and to synthesize the command filters for supervision. An application to a mobile wireless surveillance system is provided to show the feasibility of the developed approach. It is believed that the technique presented in this paper could be further applied to large-scale wireless MSNs.
55.4.38	Jong-Jae Lee, Bong-Hwan Kwon, "Active-Clamped Ripple-Free DC/DC Converter Using an Input–Output Coupled Inductor," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1842-1854, April 2008. Abstract Link Full Text Abstract: A new input-output coupled inductor (IOCI) is proposed for reducing current ripples and magnetic components. Moreover, a current-source-type circuit using active-clamp mechanism and a current doubler with synchronous rectifier are presented to achieve high efficiency in low input-output voltage applications. The configuration of the IOCI is realized by three windings on a common core, and has the properties of an input inductor at the input-side and two output inductors at the output- side. An active clamped ripple-free dc-dc converter using the proposed IOCI is analyzed in detail and optimized for high power efficiency. Experimental results for 80 W (5 V/16 A) at a constant switching frequency of 100 kHz are obtained to show the performance of the proposed converter.
55.4.39	Sehoon Oh, N. Hata, Y. Hori, "Integrated Motion Control of a Wheelchair in the Longitudinal, Lateral, and Pitch Directions," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1855-1862, April 2008. Abstract Link Full Text Abstract: The motion of a wheelchair is different from any other vehicle. It needs control in three dimensions: the longitudinal, the lateral, and the pitch direction. This paper takes this point into consideration and provides a 3-D control of a wheelchair. We focus on the control of a push-rim power-assist wheelchair. The main objective of this paper is to provide a wheelchair rider with 3-D assistance that guarantees power and safety. To this end, three kinds of assist controls are proposed: the disturbance attenuation controls are designed for the longitudinal and lateral directions while the tip-over prevention control is designed for the pitch direction. These controls for three directions can be integrated by appropriately taking advantage of system configuration. We demonstrate that all these controls can work independently for each purpose and we show experimental results.
55.4.40	Jae-Kyu Park, Hyun-Lark Do, Bong-Hwan Kwon, "Asymmetric Current Buildup Sustainer for AC Plasma Display Panel," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1863-1870, April 2008. Abstract Link Full Text Abstract: A new driving method for a plasma display panel (PDP) is proposed. In the proposed driving circuit, an asymmetric current buildup technique increases the flexibility in the rising and falling times of the panel voltage, and reduces the peak and root mean square values of the inductor currents. Moreover, the switching stresses of the main sustain switches are reduced, while all the advantages of the conventional series-resonant method are maintained. The operation principle of the proposed circuit is presented in detail. A 42-in ac PDP equipped with the proposed driving method is investigated. Letters to the Editor
55.4.41	Z. Kaczmarczyk, W. Jurczak, "A Push–Pull Class-E Inverter With Improved Efficiency," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1871-1874, April 2008. Abstract Link Full Text Abstract: This paper presents a concept for improving the efficiency of a push-pull Class-E inverter. The concept consists of lowering the root-mean-square transistor current (in reducing the transistor power losses) only by adding a differential capacitor to a push-pull Class-E topology. Theoretical explanations and confirming experimental results are given.
55.4.42	Sang-Kyoo Han, Tae-Sung Kim, Gun-Woo Moon, Myung-Joong Youn, "High Efficiency Active Clamp Forward Converter for Sustaining Power Module of Plasma Display Panel," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1874-1876, April 2008. Abstract Link Full Text Abstract: A new high efficiency active clamp forward converter for the sustaining power module of a plasma display panel is proposed. It features zero voltage switching, a simpler structure, lower cost, less mass, and no effective duty loss. Furthermore, voltages across all rectifier diodes are clamped on the output voltage, which results in higher efficiency.
55.4.43	M. Malinowski, S. Bernet, "A Simple Voltage Sensorless Active Damping Scheme for Three-Phase PWM Converters With an $LCL$ Filter," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1876-1880, April 2008. Abstract Link Full Text Abstract: Active three-phase pulsewidth-modulated rectifiers are connected to the grid by an inductance or an LCL filter. Although an filter is more effective since it more efficiently attenuates the switching harmonics, it causes stability problems. To enable a stable operation, either a damping resistor or an active damping (AD) algorithm has to be used. However, while a damping resistor causes additional losses, an AD algorithm usually requires extra sensors. To avoid these disadvantages, this paper shows simulation and experimental results of a simple AC voltage sensorless AD solution that is suitable for industrial applications.
55.4.44	Guangjun Tan, Hongjun Chen, Xiaohua Zhang, "Comments on “Lagrangian Modeling and Passivity-Based Control of Three-Phase AC/DC Voltage-Source Converters”," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1881-1882, April 2008. Abstract Link Full Text Abstract: In the above paper, the author presented a Euler-Lagrange (EL) model of three-phase pulsewidth modulation AC-DC converters. However, some problems are worth being discussed in the process of Lagrangian modeling of the converters. This paper revisits the modeling of the converters and presents the proper form of the EL model of the converters.
55.4.45	"Call for papers advances in microelectromechanical systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1883-1883, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.46	"Call for papers industrial implementations of radio frequency identification (RFID)," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1884-1884, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.47	"Call for papers advances in motion control," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1885-1885, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.48	"Call for papers applications of embedded systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1886-1886, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.49	"Call for papers applications and control of doubly fed induction machines," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1887-1887, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.50	"Call for papers sliding mode control in industrial applications-part II," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. 1888-1888, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.51	"IEEE Industrial Electronics Society Information," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. C3-C3, April 2008. Abstract Link Full Text Abstract: Not Available
55.4.52	"IEEE Transactions on Industrial Electronics information for authors," IEEE Trans. on Industrial Electronics, vol. 55, no. 4, pp. C4-C4, April 2008. Abstract Link Full Text Abstract: Not Available