IEEE Transactions on Industrial Electronics

Volume 53, Number 4, August 2006 Access to the journal on IEEE XPLORE IE Transactions Home Page

Special Section Papers on Renewable Energy And Distributed Genarated Systems - Part1:Renewable Energy

53.4.1	J.M. Carrasco, L.G. Franquelo, J.T. Bialasiewicz, E. Galvan, R.C. PortilloGuisado, M.A.M. Prats, J.I. Leon, N. Moreno-Alfonso, "Power-Electronic Systems for the Grid Integration of Renewable Energy Sources: A Survey," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1002- 1016, August 2006. Abstract Link Full Text Abstract: The use of distributed energy resources is increasingly being pursued as a supplement and an alternative to large conventional central power stations. The specification of a power-electronic interface is subject to requirements related not only to the renewable energy source itself but also to its effects on the power-system operation, especially where the intermittent energy source constitutes a significant part of the total system capacity. In this paper, new trends in power electronics for the integration of wind and photovoltaic (PV) power generators are presented. A review of the appropriate storage-system technology used for the integration of intermittent renewable energy sources is also introduced. Discussions about common and future trends in renewable energy systems based on reliability and maturity of each technology are presented.
53.4.2	W. Xiao, M.G.J. Lind, W.G. Dunford, A. Capel, "Real-Time Identification of Optimal Operating Points in Photovoltaic Power Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1017- 1026, August 2006. Abstract Link Full Text Abstract: Photovoltaic power systems are usually integrated with some specific control algorithms to deliver the maximum possible power. Several maximum power point tracking (MPPT) methods that force the operating point to oscillate have been presented in the past few decades. In the MPPT system, the ideal operation is to determine the maximum power point (MPP) of the photovoltaic (PV) array directly rather than to track it by using the active operation of trial and error, which causes undesirable oscillation around the MPP. Since the output features of a PV cell vary with environment changes in irradiance and temperature from time to time, real-time operation is required to trace the variations of local MPPs in PV power systems. The method of real-time estimation proposed in this paper uses polynomials to demonstrate the power–voltage relationship of PV panels and implements the recursive least-squares method and Newton–Raphson method to identify the voltage of the optimal operating point. The effectiveness of the proposed methods is successfully demonstrated by computer simulations and experimental evaluations of two major types of PV panels, namely: 1) crystalline silicon and 2) copper–indium–diselenide thin film.
53.4.3	I.-S. Kim, M.-B. Kim, M.-J. Youn, "New Maximum Power Point Tracker Using Sliding-Mode Observer for Estimation of Solar Array Current in the Grid-Connected Photovoltaic System," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1027- 1035, August 2006. Abstract Link Full Text Abstract: A new maximum power point tracker (MPPT) for a grid-connected photovoltaic system without solar array current sensor is proposed. The solar array current information is obtained from the sliding-mode observer and fed into the MPPT to generate the reference voltage. The parameter values such as capacitances can be changed up to 50% from their nominal values, and the linear observer cannot estimate the correct state values under the parameter variations and noisy environments. The structure of a sliding-mode observer is simple, but it shows the robust tracking property against modeling uncertainties and parameter variations. In this paper, the sliding-mode observer for the solar array current has been proposed to compensate for the parameter variations. The mathematical modeling and the experimental results verify the validity of the proposed method.
53.4.4	J.-H. Park, J.-Y. Ahn, B.-H. Cho, G.-J. Yu, "Dual-Module-Based Maximum Power Point Tracking Control of Photovoltaic Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1036- 1047, August 2006. Abstract Link Full Text Abstract: The improved maximum power point tracking (MPPT) control method for small-scale dual-module photovoltaic (PV) systems is presented in this paper. With this method, the voltage and current information of each module are shared and utilized for the detection of the maximum-power point (MPP) without measuring power. This approach can be implemented in a simple structure, especially due to the elimination of memory and multiplication devices. The proposed method is verified by a hardware prototype of grid-connected dual-module PV systems with the proposed analog-implemented MPPT controller. In addition, practical issues of the proposed scheme are considered.
53.4.5	J.-M. Kwon, K.-H. Nam, B.-H. Kwon, "Photovoltaic Power Conditioning System With Line Connection," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1048- 1054, August 2006. Abstract Link Full Text Abstract: A photovoltaic (PV) power conditioning system (PCS) with line connection is proposed. Using the power slope versus voltage of the PV array, the maximum power point tracking (MPPT) controller that produces a smooth transition to the maximum power point is proposed. The dc current of the PV array is estimated without using a dc current sensor. A current controller is suggested to provide power to the line with an almost-unity power factor that is derived using the feedback linearization concept. The disturbance of the line voltage is detected using a fast sensing technique. All control functions are implemented in software with a single-chip microcontroller. Experimental results obtained on a 2-kW prototype show high performance such as an almost-unity power factor, a power efficiency of 94%, and a total harmonic distortion (THD) of 3.6%.
53.4.6	N. Mutoh, M. Ohno, T. Inoue, "A Method for MPPT Control While Searching for Parameters Corresponding to Weather Conditions for PV Generation Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1055- 1065, August 2006. Abstract Link Full Text Abstract: This paper describes a method for maximum power point tracking (MPPT) control while searching for optimal parameters corresponding to weather conditions at that time. The conventional method has problems in that it is impossible to quickly acquire the generation power at the maximum power (MP) point in low solar radiation (irradiation) regions. It is found theoretically and experimentally that the maximum output power and the optimal current, which give this maximum, have a linear relation at a constant temperature. Furthermore, it is also shown that linearity exists between the short-circuit current and the optimal current. MPPT control rules are created based on the findings from solar arrays that can respond at high speeds to variations in irradiation. The proposed MPPT control method sets the output current track on the line that gives the relation between the MP and the optimal current so as to acquire the MP that can be generated at that time by dividing the power and current characteristics into two fields. The method is based on the generated power being a binary function of the output current. Considering the experimental fact that linearity is maintained only at low irradiation below half the maximum irradiation, the proportionality coefficient (voltage coefficient) is compensated for only in regions with more than half the rated optimal current, which correspond to the maximum irradiation. At high irradiation, the voltage coefficient needed to perform the proposed MPPT control is acquired through the hill-climbing method. The effectiveness of the proposed method is verified through experiments under various weather conditions.
53.4.7	E. Roman, R. Alonso, P. Ibanez, S. Elorduizapatarietxe, D. Goitia, "Intelligent PV Module for Grid-Connected PV Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1066- 1073, August 2006. Abstract Link Full Text Abstract: Most issues carried out about building integrated photovoltaic (PV) system performance show average losses of about 20%–25% in electricity production. The causes are varied, e.g., mismatching losses, partial shadows, variations in current–voltage$(I$–$V)$characteristics of PV modules due to manufacturing processes, differences in the orientations and inclinations of solar surfaces, and temperature effects. These losses can be decreased by means of suitable electronics. This paper presents the intelligent PV module concept, a low-cost high-efficiency dc–dc converter with maximum power point tracking (MPPT) functions, control, and power line communications (PLC). In addition, this paper analyses the alternatives for the architecture of grid-connected PV systems: centralized, string, and modular topologies. The proposed system, i.e., the intelligent PV module, fits within this last group. Its principles of operation, as well as the topology of boost dc–dc converter, are analyzed. Besides, a comparison of MPPT methods is performed, which shows the best results for the incremental conductance method. Regarding communications, PLC in every PV module and its feasibility for grid-connected PV plants are considered and analyzed in this paper. After developing an intelligent PV module (with dc–dc converter) prototype, its optimal performance has been experimentally confirmed by means of the PV system test platform. This paper describes this powerful tool especially designed to evaluate all kinds of PV systems.
53.4.8	G.O. Cimuca, C. Saudemont, B. Robyns, M.M. Radulescu, "Control and Performance Evaluation of a Flywheel Energy-Storage System Associated to a Variable-Speed Wind Generator," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1074- 1085, August 2006. Abstract Link Full Text Abstract: The flywheel energy-storage systems (FESSs) are suitable for improving the quality of the electric power delivered by the wind generators and for helping these generators to contribute to the ancillary services. Supervisors must be used for controlling the power flow from a variable-speed wind generator (VSWG) to the power grid or to an isolated load. This paper investigates the control method and the energetic performances of a low-speed FESS with a classical squirrel-cage induction machine in the view of its association to a VSWG. A test bench is developed, and experimental results are presented and discussed.
53.4.9	R. Cardenas, R. Pena, M. Perez, J. Clare, G. Asher, P. Wheeler, "Power Smoothing Using a Flywheel Driven by a Switched Reluctance Machine," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1086- 1093, August 2006. Abstract Link Full Text Abstract: A control system for power smoothing using a switched reluctance machine (SRM) driving a flywheel is presented in this paper. Power smoothing is achieved by controlling the SRM to operate as a motor/generator, storing or retrieving energy from a rotating flywheel. In order to increase the rotational energy stored in the flywheel, the SRM operates at high rotational speed, and the machine phase current is controlled using single-pulse mode. To control the SRM output power, a two-dimensional lookup table is used to store the switching angles. The control strategies proposed in this paper have been experimentally implemented in a 2.5-kW prototype based on an 8/6 SRM. Experimental results are presented and discussed.
53.4.10	Z. Jiang, R.A. Dougal, "A Compact Digitally Controlled Fuel Cell/Battery Hybrid Power Source," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1094- 1104, August 2006. Abstract Link Full Text Abstract: A compact digitally controlled fuel cell/battery hybrid power source is presented in this paper. The hybrid power source composed of fuel cells and batteries provides a much higher peak power than each component alone while preserving high energy density, which is important and desirable for many modern electronic devices, through an appropriately controlled dc/dc power converter that handles the power flow shared by the fuel cell and the battery. Rather than being controlled to serve only as a voltage or current regulator, the power converter is regulated to balance the power flow to satisfy the load requirements while ensuring the various limitations of electrochemical components such as battery overcharge, fuel cell current limit (FCCL), etc. Digital technology is applied in the control of power electronics due to many advantages over analog technology such as programmability, less susceptibility to environmental variations, and low parts count. The user can set the FCCL, battery current limit, and battery voltage limit in the digital controller. A control algorithm that is suitable for regulating the multiple variables in the hybrid system is described by using a state-machine-based model; the issues about embedded control implementation are addressed; and the large-signal behavior of the hybrid system is analyzed on a voltage–current plane. The hybrid power source is then tested through simulation and validated on real hardware. This paper also discusses some important issues of the hybrid power source, such as operation under complex load profiles, power enhancement, and optimization of the hybrid system. The design presented here can not only be scaled to larger or smaller power capacities for a variety of applications but also be used for many other hybrid power sources.
53.4.11	S. Lemofouet, A. Rufer, "A Hybrid Energy Storage System Based on Compressed Air and Supercapacitors With Maximum Efficiency Point Tracking (MEPT)," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1105- 1115, August 2006. Abstract Link Full Text Abstract: In addition to the high-capacity storage facilities based on hydropower technologies, electrochemical solutions are today's candidate for storage for renewable energy sources support. However, sustainability and limited life cycles of batteries are often inhibiting factors. This paper presents a hybrid energy storage system with high life cycle, which is mainly based on compressed air, where the storage and discharge are done within maximum efficiency conditions. As the maximum efficiency conditions impose the level of converted power, an intermittent time-modulated operation mode is applied to the thermodynamic converter to obtain a variable converted mean power. A smoothly variable output power is achieved with the help of a supercapacitive auxiliary storage device used as a filter. This paper describes the concept of the system, the power–electronic interface circuits, and especially the maximum efficiency point tracking (MEPT) algorithm and the strategy used to vary the output power. In addition, this paper presents the characteristics of high-efficiency storage systems where the pneumatic machine is replaced by an oil-hydraulic and pneumatic converter, which is used under isothermal conditions. Practical results are also presented, which are recorded from a low-power pneumatic motor coupled to a small dc generator as well as from the first prototype of the final hydropneumatic system.
53.4.12	R.C. Bansal, "Automatic Reactive-Power Control of Isolated Wind–Diesel Hybrid Power Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1116- 1126, August 2006. Abstract Link Full Text Abstract: This paper presents an automatic reactive-power control of an isolated wind–diesel hybrid power system having an induction generator (IG) for a wind-energy-conversion system and synchronous generator (SG) for a diesel-generator (DG) set. To study the effect of the size of the wind-power generation on the system performance, three examples of the hybrid system are considered with different wind-power-generation capacities. The mathematical model of the system using reactive-power-flow equations is developed. Three different types of static var compensators (SVCs) commonly used in conventional power system along with IEEE type-I excitation are considered to compare their performance in a hybrid system.
53.4.13	R. Cardenas, R. Pena, M. Perez, J. Clare, G. Asher, F. Vargas, "Vector Control of Front-End Converters for Variable-Speed Wind–Diesel Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1127- 1136, August 2006. Abstract Link Full Text Abstract: This paper presents a novel power-balance control method for a wind–diesel generation feeding an isolated grid. The system is based on a variable-speed wind energy conversion system (WECS) connected to an ac load using a power converter. An energy storage system (ESS), connected to the ac load using an additional converter, is used to balance the power generated by the WECS with the load. In this paper, the vector control systems for both interfacing power converters are discussed; the control uses the WECS converter to regulate the ac load voltage and the ESS converter to regulate the power flow to achieve a power balance. A small signal model is used to design the control systems. Finally, the proposed control is implemented in a 2-kW experimental prototype and the experimental results are fully analyzed and discussed in the paper.
53.4.14	J.T. Bialasiewicz, E. Muljadi, "Analysis of Renewable-Energy Systems Using RPM-SIM Simulator," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1137- 1143, August 2006. Abstract Link Full Text Abstract: Renewable-energy systems that are under development need a simulation-based analysis to ensure system stability, power quality, and reliability. Such an analysis may reveal design modifications that need to be made before the system is implemented in the field. The modular simulator RPM-SIM, available on the National Renewable Energy Laboratory Web site (http://wind.nrel.gov/designcodes/simulators/rpmsim/), facilitates a low-cost application-specific study of the dynamics of the wind–solar–diesel hybrid power systems. This paper discusses the principal modules of the simulator and provides several examples of a simulation-based analysis of the renewable-energy systems. These examples illustrate the importance of a simulation-based study of the grid-connected and stand-alone or autonomous systems. The RPM-SIM is open-ended and can be easily expanded.
53.4.15	H. Li, M. Steurer, K.L. Shi, S. Woodruff, D. Zhang, "Development of a Unified Design, Test, and Research Platform for Wind Energy Systems Based on Hardware-in-the-Loop Real-Time Simulation," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1144- 1151, August 2006. Abstract Link Full Text Abstract: Traditionally, offline modeling and simulation has been the tool of choice for improving wind energy system control strategies and their utility system integration. This paper exploits how a newly established real-time hardware-in-the-loop (HIL) test facility, which is designed for testing all-electric ship propulsion systems, can be utilized for wind energy research. The test site uses two 2.5-MW/220-rpm dynamometers and a 5-MW variable voltage and frequency converter to emulate a realistic dynamic environment, both mechanically and electrically. The facility is controlled by a digital real-time electric power system simulator that is capable of simulating electrical networks and control systems of substantial complexity, typically with a 50-$muhboxs$time step. Substantial input/output allows the feedback of measured quantities into the simulation. A 15-kW mock-up motor–generator set is used to demonstrate some critical aspects of the concept including the implementation of a proposed neural-network-based sensorless maximum wind energy capture control. From the dynamic test results presented, it is concluded that the proposed system shows great potential for the development of a unified wind energy design, test, and research platform.
53.4.16	V. DelliColli, P. Cancelliere, F. Marignetti, R. DiStefano, M. Scarano, "A Tubular-Generator Drive For Wave Energy Conversion," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1152- 1159, August 2006. Abstract Link Full Text Abstract: This paper illustrates the operation of a tubular-machine drive as a linear generator for a heave-buoy wave energy conversion. Linear generators, which are adopted in marine power plants, offer the advantage of generating without introducing any conversion crank gear or hydraulic system. The use of a tubular-machine topology allows the electromagnetic thrust density to be improved. This paper briefly summarizes the principles of marine wave buoy interaction and reports the design analysis and control of a permanent-magnet (PM) synchronous tubular linear machine based on a scaled generator prototype and on a rotating simulation test bench. Drive Control
53.4.17	Y. Xiao, K.Y. Zhu, "Optimal Synchronization Control of High-Precision Motion Systems," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1160- 1169, August 2006. Abstract Link Full Text Abstract: Recently, in the motion control area, one of the most challenging problems has been synchronization control of multiple motion axes or drivers. Unfortunately, the majority of the previous approaches have not fully addressed the synchronization problem when the system performs a complex motion. In this paper, a novel synchronized design of the high-precision motion control system is presented. The basic idea is to introduce the coupling and synchronization factors into the definition of the synchronization error. Then, a new quadratic performance index incorporating the synchronization errors of the multiple motion axes is introduced so that the resulting control law generates the cross-coupling control action, and as a consequence, improved tracking and synchronization performance can be obtained. The key to the success of the new design is to ensure that each motor tracks its desired trajectory while synchronizing motion with others. Computer simulations and real-time experiments on a servo system with two permanent-magnet linear motors demonstrate the effectiveness of the method.
53.4.18	J. CatalaiLopez, L. Romeral, A. Arias, E. Aldabas, "Novel Fuzzy Adaptive Sensorless Induction Motor Drive," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1170- 1178, August 2006. Abstract Link Full Text Abstract: Investigations were carried out on a novel sensorless drive for induction motors, based on the combination of an open-loop (OL) estimator and a steady-state (SS) estimator. The novelty of this new sensorless structure is obtained by an intelligent mixing of the OL estimator response with the SS one. A fuzzy system weights the two estimated speed values according to the motor operating point. Then, the final speed value is obtained averaging the previously weighted speed values. Moreover, the OL estimator response is improved by means of using a fuzzy-controlled adaptive filter that selects the optimum cutoff frequency. The aim of this paper is to obtain a moderate performance sensorless drive for induction motors that could be easily implemented for industrial applications without a high computational effort. Simulation and experimental results illustrate the operation and performance of the proposed fuzzy-logic-based sensorless drive.
53.4.19	O. Wallmark, L. Harnefors, "Sensorless Control of Salient PMSM Drives in the Transition Region," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1179- 1187, August 2006. Abstract Link Full Text Abstract: This paper considers speed and position estimation of salient permanent-magnet synchronous machines (PMSMs). An estimator of phase-locked loop (PLL) type is considered. Signal injection techniques are used in the zero-speed and low-speed regions, while information found in the back electromotive force (EMF) is used for higher speeds. Particular focus is put on the transition region, i.e., the speed region where the estimator switches between signal-injection and back-EMF-based methods. It is shown that the estimator may become unstable for certain setups of machine parameters and operating conditions if the transition region is determined incorrectly. To avoid this instability, design rules for how the transition region should be determined, as well as recommended selections for all parameters introduced, are given. The results of the analysis are also supported with experimental results.
53.4.20	J. Salomaki, M. Hinkkanen, J. Luomi, "Sensorless Control of Induction Motor Drives Equipped With Inverter Output Filter," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1188- 1197, August 2006. Abstract Link Full Text Abstract: This paper deals with the speed sensorless vector control of an induction motor in a special case where the output voltage of the pulsewidth-modulated inverter is filtered by an inductance–capacitance$(LC)$filter. The system states are estimated by means of an adaptive full-order observer, and no additional voltage, current, or speed measurements are needed. The rotor speed adaptation is based on the estimation error of the inverter output current. Quasi-steady-state and linearization analyses are used to design an observer that enables a wide operation region, including very low and very high speeds. A torque-maximizing control method is applied in the field-weakening region. Simulation and experimental results show that the performance is comparable to that of a drive without the$LC$filter.
53.4.21	Y. Zhang, C.M. Akujuobi, W.H. Ali, C.L. Tolliver, L.-S. Shieh, "Load Disturbance Resistance Speed Controller Design for PMSM," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1198- 1208, August 2006. Abstract Link Full Text Abstract: This paper presents an linear-quadratic-regulator-based proportional–integral–differential equivalent controller design method for a permanent-magnet synchronous motor. The disturbance rejection is achieved based on a multi-objective observer in which observation error is purposely retained and utilized in load disturbance compensation. This makes disturbance rejection tuning independent of the adjustment for speed command tracking; and the disturbance compensation is an integrated part of the controller output, which reduces the chance of input or state saturation. A robust stability analysis is also included for the modeling error. The proposed methodology is implemented through the dSPACE digital signal processor system, and the experimental result confirms its effectiveness.
53.4.22	F.-J. Lin, P.-H. Shen, "Robust Fuzzy Neural Network Sliding-Mode Control for Two-Axis Motion Control System," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1209- 1225, August 2006. Abstract Link Full Text Abstract: A robust fuzzy neural network (RFNN) sliding-mode control based on computed torque control design for a two-axis motion control system is proposed in this paper. The two-axis motion control system is an$x-y$table composed of two permanent-magnet linear synchronous motors. First, a single-axis motion dynamics with the introduction of a lumped uncertainty including cross-coupled interference between the two-axis mechanism is derived. Then, to improve the control performance in reference contours tracking, the RFNN sliding-mode control system is proposed to effectively approximate the equivalent control of the sliding-mode control method. Moreover, the motions at$x$-axis and$y$-axis are controlled separately. Using the proposed control, the motion tracking performance is significantly improved, and robustness to parameter variations, external disturbances, cross-coupled interference, and friction force can be obtained as well. Furthermore, the proposed control algorithms are implemented in a TMS320C32 DSP-based control computer. From the simulated and experimental results due to circle and four leaves reference contours, the dynamic behaviors of the proposed control systems are robust with regard to uncertainties.
53.4.23	T.M. O'Sullivan, C.M. Bingham, N. Schofield, "High-Performance Control of Dual-Inertia Servo-Drive Systems Using Low-Cost Integrated SAW Torque Transducers," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1226- 1237, August 2006. Abstract Link Full Text Abstract: This paper provides a systematic comparative study of compensation schemes for the coordinated motion control of two-inertia mechanical systems. Specifically, classical proportional–integral (PI), proportional–integral–derivative (PID), and resonance ratio control (RRC) are considered, with an enhanced structure based on RRC, termed RRC+, being proposed. Motor-side and load-side dynamics for each control structure are identified, with the “integral of time multiplied by absolute error” performance index being employed as a benchmark metric. PID and RRC control schemes are shown to be identical from a closed-loop perspective, albeit employing different feedback sensing mechanisms. A qualitative study of the practical effects of employing each methodology shows that RRC-type structures provide preferred solutions if low-cost high-performance torque transducers can be employed, for instance, those based on surface acoustic wave technologies. Moreover, the extra degree of freedom afforded by both PID and RRC, as compared with the basic PI, is shown to be sufficient to simultaneously induce optimal closed-loop performance and independent selection of virtual inertia ratio. Furthermore, the proposed RRC+ scheme is subsequently shown to additionally facilitate independent assignment of closed-loop bandwidth. Summary attributes of the investigation are validated by both simulation studies and by realization of the methodologies for control of a custom-designed two-inertia system.
53.4.24	A.K. Jain, N. Mohan, "Dynamic Modeling, Experimental Characterization, and Verification for SRM Operation With Simultaneous Two-Phase Excitation," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1238- 1249, August 2006. Abstract Link Full Text Abstract: Dynamic modeling of switched reluctance motors (SRMs) is usually done on a per-phase basis. However, in most applications, SRMs are used with simultaneous excitation of more than one phase. Thus, a model accounting for mutual coupling in the presence of magnetic saturation is needed to predict and optimize their performance in terms of efficiency and torque ripple. This paper presents a dynamic two-phase excitation model of the SRM. Motor symmetry is used to reduce the amount of flux linkage data needed for the model. An experimental procedure to obtain the flux linkage data is described. Measured flux linkage data for the 8/6 SRM are also included. Details of the simulation model and comparison with experimental waveforms along with their implications for performance prediction are presented.
53.4.25	J. Arellano-Padilla, G.M. Asher, M. Sumner, "Control of an AC Dynamometer for Dynamic Emulation of Mechanical Loads With Stiff and Flexible Shafts," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1250- 1260, August 2006. Abstract Link Full Text Abstract: This paper addresses the emulation of linear and nonlinear loads using a vector-controller dynamometer for the position control of mechanical loads. The emulation strategy allows an electrical machine (dynamometer) to be controlled, so as to emulate both the static and dynamic characteristics of a load with a certain bandwidth. The approach can be used for the experimental validation and testing of the electrical drives and motion-control techniques. The dynamic structure of the emulated load is always preserved. High-order systems such as loads with flexible shafts and nonlinear effects can be emulated accurately. This paper presents the dynamometer-control design, its practical implementation, and experimental results for the position control of the linear and nonlinear emulated loads. Systems with stiff and flexible shafts are considered. Finally, the experimental results are compared with the corresponding simulated loads to validate the emulation strategy.
53.4.26	K. Pietilainen, L. Harnefors, A. Petersson, H.-P. Nee, "DC-Link Stabilization and Voltage Sag Ride-Through of Inverter Drives," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1261- 1268, August 2006. Abstract Link Full Text Abstract: Previous results concerning instability of the dc link in inverter drives fed from a dc grid or via a rectifier are extended. It is shown that rectifier–inverter drives equipped with small (film) dc-link capacitors may need active stabilization. The impact of limited bandwidth and switching frequency in the inverter–motor current control loop is considered, and recommendations for selection of the dc-link capacitor, the switching frequency, and the dc-link stabilization control law in relation to each other are given. This control law is incorporated in a field-weakening (to enhance voltage sag ride-through) current controller for which design recommendations are presented. Emerging Technology
53.4.27	W. Li, Y. Hori, "An Algorithm for Extracting Fuzzy Rules Based on RBF Neural Network," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1269- 1276, August 2006. Abstract Link Full Text Abstract: A four-layer fuzzy–neural network structure and some algorithms for extracting fuzzy rules from numeric data by applying the functional equivalence between radial basis function (RBF) networks and a simplified class of fuzzy inference systems are proposed. The RBF neural network not only expresses the architecture of fuzzy systems clearly but also maintains the explanative characteristic of linguistic meaning. The fuzzy partition algorithm of input space, inference algorithm, and parameter tuning algorithm are also discussed. Simulation examples are given to illustrate the validity of the proposed algorithms.
53.4.28	C.W. Chan, S. Hua, Z. Hong-Yue, "Application of Fully Decoupled Parity Equation in Fault Detection and Identification of DC Motors," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1277- 1284, August 2006. Abstract Link Full Text Abstract: A multiple fault detection and identification method based on fully decoupled parity equations for dynamic systems with known linear and unknown nonlinear terms is presented. The fully decoupled parity equation vectors is derived and it is shown that the residuals generated from it are decoupled from other faults and the unknown nonlinear term and are sensitive only to specific actuator or sensor faults. The condition for the existence of the equation is also given. From the residuals generated from the fully decoupled parity equation, the faults are estimated using the recursive least-squares method. The performance of the proposed method is illustrated by applying it to detect, isolate, and identify faults in a simulated dc motor.
53.4.29	A.R. Mohanty, C. Kar, "Fault Detection in a Multistage Gearbox by Demodulation of Motor Current Waveform," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1285- 1297, August 2006. Abstract Link Full Text Abstract: Demodulation of vibration signal to detect faults in machinery has been a prominent prevalent technique that is discussed by a number of authors. This paper deals with the demodulation of the current signal of an induction motor driving a multistage gearbox for its fault detection. This multistage gearbox has three gear ratios, and thus, three rotating shafts and their corresponding gear mesh frequencies (GMFs). The gearbox is loaded electrically by a generator feeding an electrical resistance bank. Amplitude demodulation and frequency demodulation are applied to the current drawn by the induction motor for detecting the rotating shaft frequencies and GMFs, respectively. Discrete wavelet transform is applied to the demodulated current signal for denoising and removing the intervening neighboring features. Spectrum of a particular level, which comprises the GMFs, is used for gear fault detection.
53.4.30	B. Ayhan, M.-Y. Chow, M.-H. Song, "Multiple Discriminant Analysis and Neural-Network-Based Monolith and Partition Fault-Detection Schemes for Broken Rotor Bar in Induction Motors," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1298- 1308, August 2006. Abstract Link Full Text Abstract: Broken rotor bars in induction motors can be detected by monitoring any abnormality of the spectrum amplitudes at certain frequencies in the motor-current spectrum. It has been shown that these broken-rotor-bar specific frequencies are located around the fundamental stator current frequency and are termed lower and upper sideband components. Broken-rotor-bar fault-detection schemes should rely on multiple signatures in order to overcome or reduce the effect of any misinterpretation of the signatures that are obscured by factors such as measurement noises and different load conditions. Multiple discriminant analysis (MDA) and artificial neural networks (ANNs) provide appropriate environments to develop such fault-detection schemes because of their multiinput-processing capabilities. This paper describes two fault-detection schemes for a broken-rotor-bar fault detection with a multiple signature processing and demonstrates that the multiple signature processing is more efficient than a single signature processing. The first scheme, which will be named the “monolith scheme,” is based on a single large-scale MDA or ANN unit representing the complete operating load-torque region of the motor, while the second scheme, which will be named the “partition scheme,” consists of many small-scale MDA or ANN units, each unit representing a particular load-torque operating region. Fault-detection performance comparison between the MDA and the ANN with respect to the two schemes is investigated using the experimental data collected for a healthy and a broken-rotor-bar case. Partition scheme distributes the computational load and complexity of the large-scale single units in a monolith scheme to many smaller units, which results in the increase of the broken-rotor-bar fault-detection performance, as is confirmed with the experimental results.
53.4.31	S.-K. Oh, W. Pedrycz, H.-S. Park, "A New Approach to the Development of Genetically Optimized Multilayer Fuzzy Polynomial Neural Networks," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1309- 1321, August 2006. Abstract Link Full Text Abstract: In this paper, the authors propose and investigate a new category of neurofuzzy networks—fuzzy polynomial neural networks (FPNNs)—and develop a comprehensive design methodology involving mechanisms of genetic optimization and, in particular, genetic algorithms (GAs). The conventional FPNNs developed so far are based on mechanisms of self-organization and evolutionary optimization. The design of the network exploits the extended group method of data handling, with some essential parameters of the network being provided by the designer and kept fixed throughout the overall development process. This restriction may hamper a possibility of producing an optimal architecture of the model. The design proposed in this paper addresses this issue. The augmented genetically optimized FPNN (gFPNN) results in a structurally optimized structure and comes with a higher level of flexibility in comparison with the one encountered in the conventional FPNN. The GA-based design procedure that is applied to each layer of FPNN leads to the selection of the preferred nodes (or fuzzy polynomial neurons) available within the FPNN. In the sequel, two general optimization mechanisms are explored. First, the structural optimization is realized via GAs, whereas the ensuing, detailed parametric optimization is carried out in the setting of a standard least-square-method-based learning. The performance of gFPNN is quantified through experimentation where a number of modeling benchmarks are being used, i.e., synthetic and experimental data already experimented within fuzzy or neurofuzzy modeling. The obtained results demonstrate superiority of the proposed networks over the existing fuzzy and neural models.
53.4.32	F.-S. Kang, S.-J. Park, J.-H. Cho, W.-S. Yoon, C.-U. Kim, "High-Performance Sustain Driver for Plasma Display," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1322- 1327, August 2006. Abstract Link Full Text Abstract: The sustain driver for ac plasma display should provide alternating high-voltage pulses to ignite plasma and recover the energy discharged from the intrinsic capacitance between the scanning and sustaining electrodes inside the panel. In this paper, an efficient sustain circuit that employs a voltage boost-up function is proposed to achieve faster rise-time that would be suitable for the wide use of the address-and-display-period-separated (ADS) driving method. The proposed sustain driver improves recovery efficiency, regardless of the variation of the panel capacitance. The principle of operation, features, and simulation results are given and verified on a 7.5-in-diagonal panel at a 200-kHz operating frequency based on an experimental prototype. Robotics and Vision
53.4.33	R.-J. Wai, P.-C. Chen, "Robust Neural-Fuzzy-Network Control for Robot Manipulator Including Actuator Dynamics," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1328- 1349, August 2006. Abstract Link Full Text Abstract: This paper addresses the design and analysis of an intelligent control system for an$n$-link robot manipulator to achieve the high-precision position tracking. According to the concepts of mechanical geometry and motion dynamics, the dynamic model of an$n$-link robot manipulator including actuator dynamics is introduced initially. However, it is difficult to design a suitable model-based control scheme due to the uncertainties in practical applications, such as friction forces, external disturbances, and parameter variations. In order to deal with the mentioned difficulties, a robust neural-fuzzy-network control (RNFNC) system is investigated to the joint position control of an$n$-link robot manipulator for periodic motion. In this control scheme, a four-layer neural fuzzy network (NFN) is utilized for the major control role, and the adaptive tuning laws of network parameters are derived in the sense of a projection algorithm and the Lyapunov stability theorem to ensure network convergence as well as stable control performance. The merits of this model-free control scheme are that not only can the stable position tracking performance be guaranteed but also no prior system information and auxiliary control design are required in the control process. In addition, numerical simulations and experimental results of a two-link robot manipulator actuated by dc servo motors are provided to verify the effectiveness and robustness of the proposed RNFNC methodology.
53.4.34	H.N. Chow, Y. Xu, "Learning Human Navigational Skill for Smart Wheelchair in a Static Cluttered Route," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1350- 1361, August 2006. Abstract Link Full Text Abstract: In practice, the environments in which mobile robots operate are usually modeled in highly complex forms and, as a result, autonomous navigation and localization can be difficult. The difficulties are exacerbated for practical robots with limited on-board computational resources and complex planning algorithms, since this paradigm of environmental modeling requires enormous computational power. A novel navigation/localization learning methodology is presented to abstract and transfer the human sequential navigational skill to a robotic wheelchair by showing the platform how to respond in different local environments along a demonstrated, static cluttered route using a lookup table representation. This method utilizes limited on-board range sensing information to concisely model local unstructured environments, with respect to the robot, for navigation or localization along the learned route in order to achieve good performance with low on-line computational demand and low-cost hardware requirements. Experimental study demonstrates the feasibility of this method and some interesting characteristics of navigation, localization, and environmental modeling problems. Analysis is also conducted to investigate performance evaluation, advantages of the approach, choices of lookup table inputs and outputs, and potential generalization of this paper.
53.4.35	K.-B. Sim, K.-S. Byun, F. Harashima, "Internet-Based Teleoperation of an Intelligent Robot With Optimal Two-Layer Fuzzy Controller," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1362- 1372, August 2006. Abstract Link Full Text Abstract: Research on Internet-based teleoperation has received increased attention in the past few years. In this paper, an Internet-based teleoperation system was implemented. In order to robustly transmit the surroundings and control information of the robot, packet-type data were used. The central problem in Internet-based teleoperation is data transmission latency or data loss. For this specific problem, an autonomous mobile robot with optimal two-layer fuzzy controller (2LFC) was introduced. When data transmission is failed, the robot automatically moves and protects itself. In addition, a color detection system was implemented so that the robot can perceive an object and move to another object. The fuzzy controller was optimized by using the schema coevolutionary algorithm (SCEA), which finds an optimal solution. Using these technologies, the efficacies of the 2LFC, the SCEA, and the teleoperation system were verified.
53.4.36	S. Katsura, K. Ohnishi, "Semiautonomous Wheelchair Based on Quarry of Environmental Information," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1373- 1382, August 2006. Abstract Link Full Text Abstract: In this paper, an intelligent wheelchair robot for adaptation to an unknown environment is developed. Environmental information is a key factor to comply to an unknown and/or unstructured environment. Since the environment has an infinite number of modes, the environmental information should be classified into some modes. This paper develops a novel viewpoint of robot motion control based on quarry of environmental information. The robot adapts to the environment based on the remote and contact information. In order to adapt to the remote environment, the obstacle avoidance problem is treated. This kind of robot motion control is based on position control. On the contrary, in order to adapt to the contact information, compliance control is applied to a robot. If the robot collides with the obstacles, the impact force is relaxed by the method, and safety is improved. This controller, on the other hand, is based on force control. In this paper, position control and force control are integrated in the acceleration dimension based on acceleration control. The robust acceleration control is attained by the disturbance observer. Finally, a semiautonomous function is installed for the improvement of human operationality. The numerical and experimental results show viability of the proposed method. Letters to the Editor
53.4.37	G. Escobar, P.R. Martinez, J. Leyva-Ramos, P. Mattavelli, "A Negative Feedback Repetitive Control Scheme for Harmonic Compensation," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1383- 1386, August 2006. Abstract Link Full Text Abstract: In this letter, a different feedback structure of the repetitive control that apparently is more appropriate for applications in power electronics is proposed. Moreover, a simple analog-circuit implementation is proposed which is suitable for high-frequency power electronics applications, where digital control is unpractical due to cost and performance of available DSPs and microcontrollers.
53.4.38	Y.S. Suh, "Attitude Estimation by Multiple-Mode Kalman Filters," IEEE Trans. on Industrial Electronics, vol. 53, no. 4, pp. 1386- 1389, August 2006. Abstract Link Full Text Abstract: This letter proposes a multiple-mode Kalman filter for one-dimensional attitude estimation using low-cost accelerometer and gyroscope. The nonlinearity and time-varying parameters are partitioned into several modes; for each mode, a linear time-invariant Kalman filter is selected. Experimental results are given to verify the proposed Kalman filter.