IEEE Transactions on Industrial Electronics

Volume 55, Number 7, July 2008 Access to the journal on IEEE XPLORE IE Transactions Home Page

Special Section Papers

55.7.1	"Table of Contents," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. C1-2565, July 2008. Abstract Link Full Text Abstract: Not Available
55.7.2	"IEEE Transactions on Industrial Electronics publication information," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. C2-C2, July 2008. Abstract Link Full Text Abstract: Not Available
55.7.3	G. Spagnuolo, G. Petrone, R. Teodorescu, M. Veerachary, M. Viteli, "Guest Editorial," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2566-2568, July 2008. Abstract Link Full Text Abstract: The 22 papers in this special section focus on photovoltaic power processing systems.
55.7.4	G. Petrone, G. Spagnuolo, R. Teodorescu, M. Veerachary, M. Vitelli, "Reliability Issues in Photovoltaic Power Processing Systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2569-2580, July 2008. Abstract Link Full Text Abstract: Power processing systems will be a key factor of future photovoltaic (PV) applications. They will play a central role in transferring, to the load and/or to the grid, the electric power produced by the high-efficiency PV cells of the next generation. In order to come up the expectations related to the use of solar energy for producing electrical energy, such systems must ensure high efficiency, modularity, and, particularly, high reliability. The goal of this paper is to provide an overview of the open problems related to PV power processing systems and to focus the attention of researchers and industries on present and future challenges in this field.
55.7.5	A. Ristow, M. Begovic, A. Pregelj, A. Rohatgi, "Development of a Methodology for Improving Photovoltaic Inverter Reliability," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2581-2592, July 2008. Abstract Link Full Text Abstract: In evaluating the energy-generation potential of a photovoltaic (PV) energy system, the system is usually assumed to work without interruptions over its entire life. PV energy systems are fairly reliable, but as any complex system, they may fail. In PV systems, the inverter is responsible for the majority of failures, and most inverter failures are blamed on the aluminum electrolytic capacitors typically used in the dc bus. This paper investigates the effects of common failure modes on the reliability of PV inverters and suggests a model framework for decomposing the inverter into subsystems for more detailed study. The challenges of statistical analysis based on small data sets are discussed, and simulations are performed to illustrate the proposed model using a simple decomposition into subsystems of the inverter used in the 342-kW PV system at the Georgia Tech Aquatic Center.
55.7.6	C. Rodriguez, G.A.J. Amaratunga, "Long-Lifetime Power Inverter for Photovoltaic AC Modules," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2593-2601, July 2008. Abstract Link Full Text Abstract: This paper presents a power inverter tailored for low-power photovoltaic (PV) systems. The inverter features high reliability, thanks to a circuit topology that obviates aluminum electrolytic capacitors from the circuit. Moreover, all components, including logic and control, have been designed to exhibit high reliability at high temperatures. Three conversion stages form the power topology. First, a full bridge connected to a high-frequency transformer and a full-bridge rectifier amplifies the voltage of the PV panel to approximately 475 V. This stage is controlled by using a phase-shift pulsewidth-modulation controller that permits zero-voltage switching, thereby minimizing losses. Second, a buck converter is connected in series with the rectifier and is controlled by using current mode in order to shape the current injection into a rectified sine wave. Last, a full bridge is operated at line frequency to unfold the current injection. The amplification stage has a proportional compensator that maintains the voltage at the PV terminals constant. The current injection stage has a proportional-derivative compensator that controls the amplitude of the grid current so that the dc-link average voltage is maintained constant. Experimental results show that the peak efficiency of the system is 89%, and the total current harmonic distortion is below 5%. Finally, analyses show a designed lifetime of approximately ten years.
55.7.7	B. Sahan, A.N. Vergara, N. Henze, A. Engler, P. Zacharias, "A Single-Stage PV Module Integrated Converter Based on a Low-Power Current-Source Inverter," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2602-2609, July 2008. Abstract Link Full Text Abstract: This paper presents a transformerless three-phase inverter designed for the integration into a special type of a photovoltaic (PV) module, which is capable of providing an output voltage of several hundred volts. The chosen topology, a current-source inverter, features a single-stage power conversion system that directly feeds into the grid. The principle operation and control is described, and a modified modulation strategy is proposed to attenuate common-mode currents. A robust and highly efficient laboratory prototype of a 250-W module integrated converter has been implemented and tested. Its compact and flat design allows the direct attachment to the PV module.
55.7.8	N. Femia, G. Lisi, G. Petrone, G. Spagnuolo, M. Vitelli, "Distributed Maximum Power Point Tracking of Photovoltaic Arrays: Novel Approach and System Analysis," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2610-2621, July 2008. Abstract Link Full Text Abstract: One of the major drawbacks of photovoltaic (PV) systems is represented by the effect of module mismatching and of partial shading of the PV field. Distributed maximum power point tracking (DMPPT) is a very promising technique that allows the increase of efficiency and reliability of such systems. Modeling and designing a PV system with DMPPT is remarkably more complex than implementing a standard MPPT technique. In this paper, a DMPPT system for PV arrays is proposed and analyzed. A dc and small-signal ac model is derived to analyze steady-state behavior, as well as dynamics and stability, of the whole system. Finally, simulation results are reported and discussed.
55.7.9	Fangrui Liu, Shanxu Duan, Fei Liu, Bangyin Liu, Yong Kang, "A Variable Step Size INC MPPT Method for PV Systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2622-2628, July 2008. Abstract Link Full Text Abstract: Maximum power point tracking (MPPT) techniques are employed in photovoltaic (PV) systems to make full utilization of PV array output power which depends on solar irradiation and ambient temperature. Among all the MPPT strategies, the incremental conductance (INC) algorithm is widely used due to the high tracking accuracy at steady state and good adaptability to the rapidly changing atmospheric conditions. In this paper, a modified variable step size INC MPPT algorithm is proposed, which automatically adjusts the step size to track the PV array maximum power point. Compared with the conventional fixed step size method, the proposed approach can effectively improve the MPPT speed and accuracy simultaneously. Furthermore, it is simple and can be easily implemented in digital signal processors. A theoretical analysis and the design principle of the proposed method are provided and its feasibility is also verified by simulation and experimental results.
55.7.10	D. Sera, R. Teodorescu, J. Hantschel, M. Knoll, "Optimized Maximum Power Point Tracker for Fast-Changing Environmental Conditions," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2629-2637, July 2008. Abstract Link Full Text Abstract: This paper presents a high-performance maximum power point tracker (MPPT) optimized for fast cloudy conditions, e.g., rapidly changing irradiation on the photovoltaic panels. The rapidly changing conditions are tracked by an optimized hill-climbing MPPT method called dP-P&O. This algorithm separates the effects of the irradiation change from the effect of the tracker's perturbation and uses this information to optimize the tracking according to the irradiation change. The knowledge of the direction of the irradiation change enables the MPPT to use different optimized tracking schemes for the different cases of increasing, decreasing, or steady irradiance. When the irradiance is changing rapidly this strategy leads to faster and better tracking, while in steady-state conditions it leads to lower oscillations around the MPP. The simulations and experimental results show that the proposed dP-P&O MPPT provides a quick and accurate tracking even in very fast changing environmental conditions.
55.7.11	N.D. Benavides, P.L. Chapman, "Modeling the Effect of Voltage Ripple on the Power Output of Photovoltaic Modules," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2638-2643, July 2008. Abstract Link Full Text Abstract: This paper proposes a model for the static power loss in photovoltaic (PV) panels due to switching-frequency ripple. Small-signal modeling is used to determine the amplitude of the voltage ripple that is imposed on the PV panel, and a closed-form expression is developed for the output power. The expression is shown to be more accurate than the power loss that was predicted by small-signal modeling alone, resulting in a median error of 0.8%. The model presented allows dc-dc converter designers to more precisely choose the input filter components that are critical during times of low insolation.
55.7.12	Dzung Nguyen, B. Lehman, "An Adaptive Solar Photovoltaic Array Using Model-Based Reconfiguration Algorithm," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2644-2654, July 2008. Abstract Link Full Text Abstract: This paper proposes an adaptive reconfiguration scheme to reduce the effect of shadows on solar panels. A switching matrix connects a solar adaptive bank to a fixed part of a solar photovoltaic (PV) array, according to a model-based control algorithm that increases the power output of the solar PV array. Control algorithms are implemented in real time. An experimental reconfiguration PV system with a resistive load is presented and is shown to verify the proposed reconfigurations.
55.7.13	Jong-Pil Lee, Byung-Duk Min, Tae-Jin Kim, Dong-Wook Yoo, Ji-Yoon Yoo, "A Novel Topology for Photovoltaic DC/DC Full-Bridge Converter With Flat Efficiency Under Wide PV Module Voltage and Load Range," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2655-2663, July 2008. Abstract Link Full Text Abstract: In this paper, a novel topology for a photovoltaic (PV) dc/dc converter that can dramatically reduce the power rating and increase the efficiency of a PV system by analyzing PV module characteristics is proposed. Based on the analysis, in the proposed topology, only 30.7% power of the total PV system is needed for a dc/dc converter. Furthermore, the dc/dc converter efficiency curve is flat under wide PV module voltage and all load ranges. In particular, the converter efficiency at the lower duty range is dramatically improved. The total PV system is implemented for a 250-kW PV power conditioning system (PCS). This system has only three dc/dc converters with a 25-kW power rating. It is only one-third of the total PV PCS power. The 25-kW prototype PV dc/dc converter is introduced to experimentally verify the proposed topology. In addition, an experimental result shows that the proposed topology exhibits a good performance.
55.7.14	M.J.V. Vazquez, J.M.A. Marquez, F.S. Manzano, "A Methodology for Optimizing Stand-Alone PV-System Size Using Parallel-Connected DC/DC Converters," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2664-2673, July 2008. Abstract Link Full Text Abstract: The installation of parallel-connected dc/dc converters allows energy and cost saving in photovoltaic (PV) systems. This paper develops a methodology with several algorithms to study the annual energy saving obtained with paralleled dc/dc converters in any world location. Moreover, this methodology allows one to select the minimum-cost size of a stand-alone PV system with dc/dc converter paralleling. For this purpose, a power-system sizing computer tool has been used, but its initial capabilities have been extended. The developed methodology allows for decision taking before investment is made.
55.7.15	R. Gules, J. De Pellegrin Pacheco, H.L. Hey, J. Imhoff, "A Maximum Power Point Tracking System With Parallel Connection for PV Stand-Alone Applications," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2674-2683, July 2008. Abstract Link Full Text Abstract: This paper presents the analysis, design, and implementation of a parallel connected maximum power point tracking (MPPT) system for stand-alone photovoltaic power generation. The parallel connection of the MPPT system reduces the negative influence of power converter losses in the overall efficiency because only a part of the generated power is processed by the MPPT system. Furthermore, all control algorithms used in the classical series-connected MPPT can be applied to the parallel system. A simple bidirectional dc-dc power converter is proposed for the MPPT implementation and presents the functions of battery charger and step-up converter. The operation characteristics of the proposed circuit are analyzed with the implementation of a prototype in a practical application.
55.7.16	M. Fortunato, A. Giustiniani, G. Petrone, G. Spagnuolo, M. Vitelli, "Maximum Power Point Tracking in a One-Cycle-Controlled Single-Stage Photovoltaic Inverter," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2684-2693, July 2008. Abstract Link Full Text Abstract: In this paper, the design of the one-cycle controller of a single-stage inverter for photovoltaic applications is carried out by means of a multiobjective strategy to optimize inverter performance at both high and low insolation levels. Design constraints that account for different weather conditions are adopted. The optimization algorithm also provides useful information concerning the system sensitivity with respect to each of the controller parameters. This allows the design of a maximum power point tracking perturb and observe controller that significantly improves inverter performance. Experimental measurements confirm the predictions of theoretical and simulation results.
55.7.17	R. Gonzalez, E. Gubia, J. Lopez, L. Marroyo, "Transformerless Single-Phase Multilevel-Based Photovoltaic Inverter," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2694-2702, July 2008. Abstract Link Full Text Abstract: The elimination of the output transformer from grid- connected photovoltaic (PV) systems not only reduces the cost, size, and weight of the conversion stage but also increases the system overall efficiency. However, if the transformer is removed, the galvanic isolation between the PV generator and the grid is lost. This may cause safety hazards in the event of ground faults. In addition, the circulation of leakage currents (common-mode currents) through the stray capacitance between the PV array and the ground would be enabled. Furthermore, when no transformer is used, the inverter could inject direct current (dc) to the grid, causing the saturation of the transformers along the distribution network. While safety requirements in transformerless systems can be met by means of external elements, leakage currents and the injection of dc into the grid must be guaranteed topologically or by the inverter's control system. This paper proposes a new high-efficiency topology for transformerless systems, which does not generate common-mode currents and topologically guarantees that no dc is injected into the grid. The proposed topology has been verified in a 5-kW prototype with satisfactory results.
55.7.18	S. Daher, J. Schmid, F.L.M. Antunes, "Multilevel Inverter Topologies for Stand-Alone PV Systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2703-2712, July 2008. Abstract Link Full Text Abstract: This paper shows that versatile stand-alone photovoltaic (PV) systems still demand on at least one battery inverter with improved characteristics of robustness and efficiency, which can be achieved using multilevel topologies. A compilation of the most common topologies of multilevel converters is presented, and it shows which ones are best suitable to implement inverters for stand-alone applications in the range of a few kilowatts. As an example, a prototype of 3 kVA was implemented, and peak efficiency of 96.0% was achieved.
55.7.19	S. Busquets-Monge, J. Rocabert, P. Rodriguez, S. Alepuz, J. Bordonau, "Multilevel Diode-Clamped Converter for Photovoltaic Generators With Independent Voltage Control of Each Solar Array," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2713-2723, July 2008. Abstract Link Full Text Abstract: In photovoltaic (PV) power systems where a set of series-connected PV arrays (PVAs) is connected to a conventional two-level inverter, the occurrence of partial shades and/or the mismatching of PVAs leads to a reduction of the power generated from its potential maximum. To overcome these problems, the connection of the PVAs to a multilevel diode-clamped converter is considered in this paper. A control and pulsewidth-modulation scheme is proposed, capable of independently controlling the operating voltage of each PVA. Compared to a conventional two-level inverter system, the proposed system configuration allows one to extract maximum power, to reduce the devices voltage rating (with the subsequent benefits in device-performance characteristics), to reduce the output-voltage distortion, and to increase the system efficiency. Simulation and experimental tests have been conducted with three PVAs connected to a four-level three-phase diode-clamped converter to verify the good performance of the proposed system configuration and control strategy.
55.7.20	M. Castilla, J. Miret, J. Matas, L.G. de Vicua, J.M. Guerrero, "Linear Current Control Scheme With Series Resonant Harmonic Compensator for Single-Phase Grid-Connected Photovoltaic Inverters," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2724-2733, July 2008. Abstract Link Full Text Abstract: This paper deals with an important aspect in the operation of single-phase grid-connected photovoltaic inverters, i.e., injecting low harmonic current into the electrical grid. Specifically, we propose a linear current control scheme with a resonant harmonic compensator connected in series with a tracking regulator (the standard harmonic compensator location is in parallel with the tracking regulator). The series connection provides an efficient attenuation of the grid voltage background distortion, an accurate synchronization with the grid voltage, and a low computational time in relation to the standard control scheme. Experimental results from a digital signal processor-based laboratory prototype validate the features of the proposed control scheme.
55.7.21	C. Meza, J.J. Negroni, D. Biel, F. Guinjoan, "Energy-Balance Modeling and Discrete Control for Single-Phase Grid-Connected PV Central Inverters," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2734-2743, July 2008. Abstract Link Full Text Abstract: This paper presents a two-control loop design considering the nonlinear time-varying characteristics of a single-phase grid-connected photovoltaic (PV) full-bridge central inverter. The control scheme design is based on the energy-balance modeling of the PV system and enables the design of a voltage loop linear discrete controller ensuring the stability of the system for the whole range of PV array operating conditions. A set of experimental results carried out on a laboratory prototype is provided to validate the proposed approach.
55.7.22	Y. Ueda, K. Kurokawa, T. Tanabe, K. Kitamura, H. Sugihara, "Analysis Results of Output Power Loss Due to the Grid Voltage Rise in Grid-Connected Photovoltaic Power Generation Systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2744-2751, July 2008. Abstract Link Full Text Abstract: This paper describes the connected photovoltaic (PV) power generation system's grid overvoltage protection function and summarizes the occurrence of the output power loss due to the grid voltage rise. Power injection from the PV system will raise the voltage at the power distribution line. A power conditioning subsystem (PCS) needs to regulate its output if the voltage becomes higher than the upper limit in order to avoid the overvoltage at the power grid. Thus, a PV system cannot generate electricity under the high grid voltage. There are 553 residential PV systems installed in Ota, Japan, for the demonstration research project of clustered PV systems. Measurement data of these 2.1-MW grid-connected PV systems are used for the analysis. Only the limited number of PV systems experienced a significant amount of output energy loss due to the high grid voltage in a particular day, whereas the other system's outputs also raise the grid voltage. The causes of this maldistribution of the output energy loss are the difference of the line impedance, the difference of the starting voltage of the PCS's grid overvoltage protection function, and the imbalance of the load in single-phase three-wire power distribution systems. The present control of the PCS successfully avoids the overvoltage on the grid but cannot share the loss.
55.7.23	J.T. Bialasiewicz, "Renewable Energy Systems With Photovoltaic Power Generators: Operation and Modeling," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2752-2758, July 2008. Abstract Link Full Text Abstract: A substantial increase of photovoltaic (PV) power generators installations has taken place in recent years, due to the increasing efficiency of solar cells as well as the improvements of manufacturing technology of solar panels. These generators are both grid-connected and stand-alone applications. We present an overview of the essential research results. The paper concentrates on the operation and modeling of stand-alone power systems with PV power generators. Systems with PV array-inverter assemblies, operating in the slave-and-master modes, are discussed, and the simulation results obtained using a renewable energy power system modular simulator are presented. These results demonstrate that simulation is an essential step in the system development process and that PV power generators constitute a valuable energy source. They have the ability to balance the energy and supply good power quality. It is demonstrated that when PV array- inverters are operating in the master mode in stand-alone applications, they well perform the task of controlling the voltage and frequency of the power system. The mechanism of switching the master function between the diesel generator and the PV array-inverter assembly in a stand-alone power system is also proposed and analyzed. Finally, some experimental results on a practical system are compared to the simulation results and confirm the usefulness of the proposed approach to the development of renewable energy systems with PV power generators.
55.7.24	D. Dondi, A. Bertacchini, D. Brunelli, L. Larcher, L. Benini, "Modeling and Optimization of a Solar Energy Harvester System for Self-Powered Wireless Sensor Networks," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2759-2766, July 2008. Abstract Link Full Text Abstract: In this paper, we propose a methodology for optimizing a solar harvester with maximum power point tracking for self-powered wireless sensor network (WSN) nodes. We focus on maximizing the harvester's efficiency in transferring energy from the solar panel to the energy storing device. A photovoltaic panel analytical model, based on a simplified parameter extraction procedure, is adopted. This model predicts the instantaneous power collected by the panel helping the harvester design and optimization procedure. Moreover, a detailed modeling of the harvester is proposed to understand basic harvester behavior and optimize the circuit. Experimental results based on the presented design guidelines demonstrate the effectiveness of the adopted methodology. This design procedure helps in boosting efficiency, allowing to reach a maximum efficiency of 85% with discrete components. The application field of this circuit is not limited to self-powered WSN nodes; it can easily be extended in embedded portable applications to extend the battery life.
55.7.25	J.H. Lee, H.S. Bae, B.H. Cho, "Resistive Control for a Photovoltaic Battery Charging System Using a Microcontroller," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2767-2775, July 2008. Abstract Link Full Text Abstract: A new control algorithm has been developed, consisting of a buck-type dc/dc converter, which is used in a parallel-operated photovoltaic battery charging system. From the past research, it has been analyzed that the current loop that is generally used in the parallel operation of the power conditioner has an inherent stability problem in the large-signal domain in the photovoltaic system. The proposed algorithm directly transforms the effective input characteristic of the converter seen by the solar array into a resistive load, which is controlled by a microcontroller-based unit. Thus, the resulting system eliminates the instability associated with the current loop in the photovoltaic system. In addition, it is simple, flexible, and easily expandable. To analyze the effects of the one-sample delay caused by the digital controller, the emulated function in the case of average current mode control is modeled using small-signal approaches, and the design criteria are presented. The experimental results from 180-W prototype hardware show that the proposed algorithm has a simple implementation structure and can stabilize the system in the entire region of the solar array. Multiphase Systems
55.7.26	Ching-Tsai Pan, Yi-Hung Liao, "Modeling and Control of Circulating Currents for Parallel Three-Phase Boost Rectifiers With Different Load Sharing," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2776-2785, July 2008. Abstract Link Full Text Abstract: In this paper, a general definition of circulating currents for each phase of each paralleled converter with different load sharing is first proposed. Then, based on this definition, the corresponding circulating current index and unbalance rate for paralleled converter are proposed to provide one with a quantitative measure about the serious status of power quality. Third, the corresponding general model of circulating currents is also derived for understanding the governing dynamic behavior of circulating currents. Fourth, based on the derived model, the proposed coordinate control strategy is then proposed for different load sharing controls, as well as elimination of circulating currents. Furthermore, a prototype system is also constructed, and the proposed coordinate control is implemented using TMS320F2812 digital signal processor. Both simulation and experimental results indeed show the effectiveness of the proposed coordinate control.
55.7.27	Bin Wu, J. Pontt, J. Rodriguez, S. Bernet, S. Kouro, "Current-Source Converter and Cycloconverter Topologies for Industrial Medium-Voltage Drives," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2786-2797, July 2008. Abstract Link Full Text Abstract: This paper, along with an earlier published paper as Part 1, provides a comprehensive review of the state of the art of high-power converters (above 1 MW) for adjustable-speed ac drives. In this highly active area, different converter topologies have been developed for various drive applications in the industry. Due to its extensive coverage, the subject is divided into two parts: multilevel voltage source and current source converter topologies. This paper is focused on the second part and covers the current source converter technologies, including pulsewidth-modulated current-source inverters (CSIs) and load-commutated inverters. In addition, this paper also addresses the present status of the direct converter, which is also known as cycloconverter (CCV). This paper focuses on the latest CSI and CCV technologies and an overview of the commonly used modulation schemes. It also provides the latest technological advances and future trends in CSI- and CCV-fed large drives. This paper serves as a useful reference for academic researchers and practicing engineers in the field of power converters and adjustable-speed drives. Motors and Actuators
55.7.28	Xiaoping Tu, L.-A. Dessaint, R. Champagne, K. Al-Haddad, "Transient Modeling of Squirrel-Cage Induction Machine Considering Air-Gap Flux Saturation Harmonics," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2798-2809, July 2008. Abstract Link Full Text Abstract: A transient model of a squirrel-cage induction machine, including air-gap flux saturation harmonics, is presented in this paper. The machine model is based on a flux model, where the winding magnetizing fluxes are directly calculated from the resultant air-gap magnetomotive force, avoiding the use of complicated inductance harmonics. The effects of the fundamental and third harmonic components of the air-gap flux are incorporated in the model by two saturation factors. Moreover, the saturation effects are incorporated in the machine's torque equation, allowing the model to investigate the machine's performance under any load condition. The machine parameters, including saturation data, are obtained via the conventional no-load and locked-rotor tests, with access to the stator neutral connection. The proposed model is validated by experimental results for a squirrel-cage machine and can be used to predict machine transient states. Signal Processing and Control
55.7.29	Yuan Yao, F. Dai, R.C. Jaeger, J.D. Cressler, "A 12-Bit Cryogenic and Radiation-Tolerant Digital-to-Analog Converter for Aerospace Extreme Environment Applications," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2810-2819, July 2008. Abstract Link Full Text Abstract: This paper presents an 80-MHz 12-bit cryogenic low-power digital-to-analog converter (DAC) implemented in a 0.5-mum SiGe BiCMOS technology. The cryogenic DAC is capable of operating over an ultrawide temperature (UWT) ranging from -180degC to +120degC and under the high-energy particle radiation environment on the lunar surface. A bandgap voltage reference for the UWT applications is designed using SiGe heterojunction bipolar transistors, and the current-steering DAC is implemented using a segmented current source array. The design considerations for both extreme temperature and radiation environments are discussed. The cryogenic and radiation-tolerant DAC chip occupies a die area of 3.5 times 1.8 mm² and consumes only 39.6 mW from a 3.3-V supply voltage. The maximum DAC sampling rate was measured at 80 MS/s at -180degC using a 40-pin dual in-line package. Instrumentation and Sensors
55.7.30	M. Zamora, M.P. Henry, "An FPGA Implementation of a Digital Coriolis Mass Flow Metering Drive System," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2820-2831, July 2008. Abstract Link Full Text Abstract: Coriolis mass flow metering provides a direct measurement of mass flow and is generally regarded as the most accurate and precise flow technology in common use in industry. This paper describes the role of the field-programmable gate array (FPGA) hardware, which is programmed using the Handel-C language, in the implementation of a "digital" Coriolis meter, which replaces the conventional analog positive feedback system used to maintain flowtube oscillation. The FPGA is coupled to a microprocessor, which carries out conventional measurement tasks and selects the drive parameters to be used by the FPGA. The resulting meter is able to maintain the operation in more difficult process conditions, including two-phase flow, which has previously caused Coriolis meters to cease oscillation. The system described in this paper is used in a commercial meter that has been successfully applied to two-phase industrial applications. Embedded Systems
55.7.31	F. Baronti, F. Lenzi, R. Roncella, R. Saletti, O. Di Tanna, "Electronic Control of a Motorcycle Suspension for Preload Self-Adjustment," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2832-2837, July 2008. Abstract Link Full Text Abstract: This paper describes the application of electronics to the control of the rear suspension of a motorcycle. The aim of the system is to make the suspension work around its optimal operating point, so that the safety and comfort of the vehicle can be improved. In fact, variations of the load carried by the vehicle determine a change of the suspension spring compression that moves the operating point away from the optimal value. Spring compression can also be changed by varying the suspension preload. The electronic system described here reveals load changes and automatically adjusts the motorcycle suspension preload in order to compensate the load variation and keep the suspension to its optimal operating point. The system is based on a linear position sensor that monitors the actual stroke of the suspension and a microcontroller that executes the control algorithm and drives the preload actuator. Road tests carried out on a motor scooter equipped with the system show its correct functionality and demonstrate the achievement of a better operation of the suspension with simple hardware and cost affordable for the two-wheel market.
55.7.32	"Call for papers sliding mode control in industrial applications-part II," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2838-2838, July 2008. Abstract Link Full Text Abstract: Not Available
55.7.33	"Call for papers-building automation, control and management," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2839-2839, July 2008. Abstract Link Full Text Abstract: Not Available
55.7.34	"Call for papers-efficient and reliable photovoltaic systems," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. 2840-2840, July 2008. Abstract Link Full Text Abstract: Not Available
55.7.35	"IEEE Transactions on Industrial Electronics information for authors," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. C4-C4, July 2008. Abstract Link Full Text Abstract: Not Available
55.7.36	"IEEE Industrial Electronics Society Information," IEEE Trans. on Industrial Electronics, vol. 55, no. 7, pp. C3-C3, July 2008. Abstract Link Full Text Abstract: Not Available