IEEE Transactions on Industrial Electronics

Volume 56, Number 7, July 2009 Access to the journal on IEEE XPLORE IE Transactions Home Page

Special Section on Industrial Implementation of RFID Systems

56.7.1	F. F. Dai, C. E. Stroud, J. B. Zhang, "Guest Editor," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2295-2298, July 2009. Abstract Link Full Text Abstract: Not Available Special Section Papers
56.7.2	Y.-S. Hwang, H.-C. Lin, "A New CMOS Analog Front End for RFID T," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2299-2307, July 2009. Abstract Link Full Text Abstract: This paper presents a new CMOS integrated analog front-end circuit for 13.56-MHz radio-frequency identification tags. The proposed analog front end consists of a novel CMOS rectified voltage multiplier, a voltage regulator, and a new frequency-shift keying (FSK) demodulator. The proposed single-stage rectifier employing only a PMOS/NMOS pass transistor, an inverter, and one capacitor gets minimal active area and enhances the power conversion efficiency. Moreover, a new technique is used in the proposed FSK demodulator, which includes the data recovery circuit, the multiplexer, the shift register, the phase frequency detector, and the charge-pump circuit. The analog front end has been fabricated in a CMOS 0.35-$muhbox{m}$ 2P4M technology. The demodulator circuit supports a data rate of 10 kb/s to 1 Mb/s. The power consumption is as low as 0.96 mW, and the chip area without pads is only 0.74 mm $times$ 0.43 mm. Experimental results show that the proposed analog front end works well and confirms the theoretical analysis.
56.7.3	J.-W. Lee, B. Lee, "A Long-Range UHF-Band Passive RFID Tag IC Based on High- $Q$ Design Appro," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2308-2316, July 2009. Abstract Link Full Text Abstract: We present a fully integrated long-range UHF-band passive radio-frequency-identification tag chip fabricated in 0.35-$muhbox{m}$ CMOS using titanium (Ti/Al/Ta/Al)–silicon Schottky diodes. The diodes showed low turn-on voltages of 95 and 140 mV for diode currents of 1 and 5 $muhbox{A}$, respectively. In addition, the Schottky diodes exhibited low-resistive loss, and a high-$Q$ -factor design approach was exploited to achieve a long read range for the tag integrated circuit (IC). An optimized voltage multiplier resulted in an excellent sensitivity of $-$ 14.8 dBm and corresponding power-conversion efficiency of 36.2% for generating an output voltage of 1.5 V at 900 MHz. The range analysis of the measured multiplier performance indicated an operating range of more than 9 m at 4-W Effective Isotropically Radiated Power reader power. The subthreshold-mode operation of an ASK demodulator allowed ultralow power operation. Under power consumption as low as 27 nW, the demodulator supported a data rate of 150 kb/s and a modulation depth of 40%. A new architecture for generating a stable system clock (2.2 MHz) for the tag IC was employed to deal with supply voltage and temperature variations. Measurements showed that the clock generator had an error of 0.91% from the center frequency owing to an 8-b digital calibration scheme.
56.7.4	Y. Yao, J. Wu, Y. Shi, F. F. Dai, "A Fully Integrated 900-MHz Passive RFID Transponder Front End With Novel Zero-Threshold RF–DC Rectif," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2317-2325, July 2009. Abstract Link Full Text Abstract: This paper presents a fully integrated CMOS analog front end for a passive 900-MHz radio-frequency identification (RFID) transponder. The power supply in this front end is generated from the received RF electromagnetic energy by using an RF–dc voltage rectifier. In order to improve the compatibility with standard CMOS technology, Schottky diodes in conventional RF–dc rectifiers are replaced by diode-connected MOS transistors with zero threshold. Meanwhile, theoretical analyses for the proposed rectifier are provided and verified by both simulation and measurement results. The design considerations of the pulsewidth-modulation (PWM) demodulator and the backscatter modulator in the front end are also discussed for low-power applications. The proposed front end is implemented in a 0.35-$muhbox{m}$ 2P4M CMOS technology. The whole chip occupies a die area of $490 times 780 mu hbox{m}^{2}$ and consumes only 2.1 $muhbox{W}$ in reading mode under a self-generated 1.5-V supply voltage. The measurement results show that the proposed rectifier can properly operate with a $-$14.7-dBm input RF power at a power conversion efficiency of 13.0%. In the proposed RFID applications, this sensitivity corresponds to 10.88-m communication distance at 4-W equivalent isotropically radiated power from a reader base station.
56.7.5	J.-B. Eom, S.-B. Yim, T.-J. Lee, "An Efficient Reader Anticollision Algorithm in Dense RFID Networks With Mobile RFID Read," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2326-2336, July 2009. Abstract Link Full Text Abstract: In parallel with the proliferation of radio-frequency identification (RFID) systems, many RFID readers have been increasingly employed. In such an environment, collision among readers becomes a serious problem. Existing anticollision algorithms, depending on the information of neighboring readers, may require constant effort in order to grasp such information. Although it may be given by a server or a coordinator, they may not be suitable in dense and dynamic RFID networks with mobile readers. In this paper, we propose an efficient reader anticollision algorithm using a polling server in dense and dynamic RFID networks with mobile readers. Owing to the assistance of the server, the readers can rapidly decide whether they can work or not without interfering neighbors and can be easily synchronized. Our proposed algorithm is simple and makes readers aware of neighbors to minimize reader collisions. Performance evaluation shows how many readers can operate in a network and indicates that our proposed algorithm is more efficient than distributed color selection, colorwave, and hierarchical Q-learning algorithm, particularly in dense and mobile environments.
56.7.6	D.-Y. Kim, H.-G. Yoon, B.-J. Jang, J.-G. Yook, "Effects of Reader-to-Reader Interference on the UHF RFID Interrogation Ra," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2337-2346, July 2009. Abstract Link Full Text Abstract: In this paper, the effects of ultrahigh-frequency band passive radio-frequency identification (RFID) reader-to-reader interference are investigated in terms of the interrogation range. A reader-to-reader interference model based on interference statistics is proposed, and the nominal interrogation range of a desired reader is derived by this model. In order to evaluate the RFID reader-to-reader interference quantitatively, the interrogation-range-reduction ratio (IRRR) is also defined. For a simple case with only one interfering reader, the analytic and experimental results are in good agreement. Reader–reader distance achieving 0% IRRR, indicating no interference between the readers, is 1200 m for the multiple-reader environment. Additionally, IRRR values are calculated in various environments according to the North American and Korean regulations. The maximum number of allowable interfering readers is then calculated by the proposed interference model and a target IRRR.
56.7.7	A. Soylemezoglu, M. J. Zawodniok, S. Jagannathan, "RFID-Based Smart Free," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2347-2356, July 2009. Abstract Link Full Text Abstract: This paper presents a novel radio-frequency identification (RFID)-based smart freezer using a new inventory-management scheme for extremely low temperature environments. The proposed solution utilizes backpressure inventory control, systematic selection of antenna configuration, and antenna power control. The proposed distributed-inventory-control (DIC) scheme dictates the amount of items transferred through the supply chain. When a high item visibility is ensured, the control scheme maintains the desired level of inventory at each supply-chain echelon. The performance of the DIC scheme is guaranteed using a Lyapunov-based analysis. The proposed RFID antenna-configuration design methodology coupled with locally asymptotically stable distributed power control ensures a 99% read rate of items while minimizing the required number of RFID antennas in the confined cold chain environments with non-RF-friendly materials. The proposed RFID-based smart-freezer performance is verified through simulations of supply chain and experiments on an industrial freezer testbed operating at $-100 ^{circ}hbox{F}$.
56.7.8	F. Gandino, B. Montrucchio, M. Rebaudengo, E. R. Sanchez, "On Improving Automation by Integrating RFID in the Traceability Management of the Agri-Food Sec," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2357-2365, July 2009. Abstract Link Full Text Abstract: Traceability is a key factor for the agri-food sector. Radio-frequency identification (RFID) technology, which is widely adopted for supply chain management, can be used effectively for the traceability management. In this paper, a framework for the evaluation of a traceability system for the agri-food industry is presented, and the automation level in an RFID-based traceability system is analyzed and compared with respect to traditional ones. Internal and external traceabilities are both considered and formalized, in order to classify different environments, according to their automation level. Traceability systems used in a sample sector are experimentally analyzed, showing that, by using RFID technology, agri-food enterprises increase their automation level and also their efficiency, in a sustainable way.
56.7.9	S. Park, S. Hashimoto, "Autonomous Mobile Robot Navigation Using Passive RFID in Indoor Environm," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2366-2373, July 2009. Abstract Link Full Text Abstract: This paper proposes an efficient method for localization and pose estimation for mobile robot navigation using passive radio-frequency identification (RFID). We assume that the robot is able to identify IC tags and measure the robot's pose based on the relation between the previous and current location according to the IC tags. However, there arises the problem of uncertainty of location due to the nature of the antenna and IC tags. In other words, an error is always present which is relative to the sensing area of the antenna. Many researches have used external sensors in order to reduce the location errors, with few researches presented involving purely RFID driven systems. Our proposed algorithm that uses only passive RFID is able to estimate the robot's location and orientation more precisely by using trigonometric functions and the IC tags' Cartesian coordinates in a regular gridlike pattern. The experimental results show that the proposed method effectively estimates both the location and the pose of a mobile robot during navigation.
56.7.10	P. V. Nikitin, K. V. S. Rao, "LabVIEW-Based UHF RFID Tag Test and Measurement Sys," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2374-2381, July 2009. Abstract Link Full Text Abstract: In this paper, we describe a UHF radio-frequency-identification tag test and measurement system based on National Instruments LabVIEW-controlled PXI RF hardware. The system operates in 800–1000-MHz frequency band with a variable output power up to 30 dBm and is capable of testing tags using Gen2 and other protocols. We explain testing methods and metrics, describe in detail the construction of our system, show its operation with real tag measurement examples, and draw general conclusions. Multiphase Systems
56.7.11	R. Gupta, A. Ghosh, A. Joshi, "Characteristic Analysis for Multisampled Digital Implementation of Fixed-Switching-Frequency Closed-Loop Modulation of Voltage-Source Inver," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2382-2392, July 2009. Abstract Link Full Text Abstract: In this paper, a fixed-switching-frequency closed-loop modulation of a voltage-source inverter (VSI), upon the digital implementation of the modulation process, is analyzed and characterized. The sampling frequency of the digital processor is considered as an integer multiple of the modulation switching frequency. An expression for the determination of the modulation design parameter is developed for smooth modulation at a fixed switching frequency. The variation of the sampling frequency, switching frequency, and modulation index has been analyzed for the determination of the switching condition under closed loop. It is shown that the switching condition determined based on the continuous-time analysis of the closed-loop modulation will ensure smooth modulation upon the digital implementation of the modulation process. However, the stability properties need to be tested prior to digital implementation as they get deteriorated at smaller sampling frequencies. The closed-loop modulation index needs to be considered maximum while determining the design parameters for smooth modulation. In particular, a detailed analysis has been carried out by varying the control gain in the sliding-mode control of a two-level VSI. The proposed analysis of the closed-loop modulation of the VSI has been verified for the operation of a distribution static compensator. The theoretical results are validated experimentally on both single- and three-phase systems.
56.7.12	M. L. G. Kissin, J. T. Boys, G. A. Covic, "Interphase Mutual Inductance in Polyphase Inductive Power Transfer Syst," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2393-2400, July 2009. Abstract Link Full Text Abstract: Roadway powered electric vehicles with minimal or no onboard energy storage have been proposed for many years, but the concept has only recently become feasible via three-phase inductive power transfer (IPT) systems. A wide zone can be created over which power transfer is relatively constant. This gives good tolerance to the alignment of the pickup relative to the track allowing simple low-cost pickup structures to be used. While three-phase IPT tracks make the vehicle pickup and power transfer simpler, they are difficult for the power supply to drive due to the presence of mutual coupling between the track phases resulting from the physical layout of the track. These mutual inductances induce voltages within each track phase that, because of the inductor-capacitor-inductor network, cause large currents within the power supply inverter and imbalances within the system. This paper presents an analytical assessment of the problems caused by the interphase mutual inductance, and three possible solutions. Two of the methods involve modifications to the track layout to alter or remove the mutual inductances, while the third and preferred technique requires additional ferrite cores between the various phases to compensate this adverse mutual inductance without affecting the power transfer to the pickup loads.
56.7.13	A. Luo, C. Tang, Z. Shuai, J. Tang, X. Y. Xu, D. Chen, "Fuzzy-PI-Based Direct-Output-Voltage Control Strategy for the STATCOM Used in Utility Distribution Syst," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2401-2411, July 2009. Abstract Link Full Text Abstract: In this paper, the control strategy for the static synchronous compensator (STATCOM) used in utility distribution systems is investigated, and a novel fuzzy-PI-based direct-output-voltage (DOV) control strategy is presented. Based on power balancing principle and feedforward decoupling control, this novel DOV control strategy cannot only reduce the active and reactive current control loops of a conventional double-loop control strategy but also achieve the decoupling control to regulate dc-link voltage and maintain the voltages at the point of common coupling (PCC). In order to effectively improve the immunity capability of this novel DOV control strategy to the uncertainties in system parameters, two fuzzy PI controllers are separately employed to maintain the voltages at the PCC and to simultaneously regulate dc-link voltage. The validity and effectiveness of this novel control strategy for the STATCOM used in utility distribution systems have been verified by simulation results, and a scaled physical prototype rated at $pm$300 kVAr is also developed to test the STATCOM system.
56.7.14	B. C. Sung, D. K. Park, J. W. Park, T. K. Ko, "Study on a Series Resistive SFCL to Improve Power System Transient Stability: Modeling, Simulation, and Experimental Verificat," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2412-2419, July 2009. Abstract Link Full Text Abstract: This paper presents a study to determine the optimal resistive value of a superconducting fault-current limiter (SFCL) for enhancing the transient stability of a power system more effectively. A resistive type of SFCL, which provides quick system protection, is modeled. Then, the optimal resistive value of the SFCL connected in series with a transmission line during a short-circuit fault is systematically determined by applying the equal-area criterion based on the power-angle curves. To verify the effectiveness of the optimal value of the proposed SFCL for reducing the value of fault current, several case studies are carried out by both simulation and experimental tests, particularly including the 220-V/300-A-scale laboratory and 13.2-kV/630-A-scale distribution system hardware tests. The results show that the optimal resistive value of the SFCL determined by the proposed method improves effectively the transient stability and damping performances during a fault over the other values determined by an ad hoc approach.
56.7.15	A. V. Stankovic, K. Chen, "A New Control Method for Input–Output Harmonic Elimination of the PWM Boost-Type Rectifier Under Extreme Unbalanced Operating Conditi," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2420-2430, July 2009. Abstract Link Full Text Abstract: Under severe fault conditions in the distribution system, not only input voltages but also input impedances must be considered as unbalanced. This paper presents a new control method for input–output harmonic elimination of the pulsewidth-modulation (PWM) boost-type rectifier under conditions of both unbalanced input voltages and unbalanced input impedances. The range of imbalance in both input voltages and input impedances, for which the proposed method is valid, is analyzed in detail. An analytical approach for complete harmonic elimination shows that PWM boost-type rectifier can operate at unity power factor under extremely unbalanced operating conditions resulting in a smooth (constant) power flow from ac to dc side. Based on the analyses in open-loop configuration, a feedforward control method is proposed. Elimination of harmonics at ac and dc side of the converter affects the cost of dc link capacitor and ac side filter. The proposed method is very useful when the PWM boost-type rectifier is subject to extreme imbalance due to severe fault conditions in the power system. In addition, by using the proposed method, the PWM boost-type rectifier can be operated from the single-phase supply in cases where three-phase source is not available. Simulation results show excellent response and stable operation of the PWM boost-type rectifier under the proposed control algorithm. Experimental and simulation results are in excellent agreement.
56.7.16	A. Luo, C. Tang, Z. K. Shuai, W. Zhao, F. Rong, K. Zhou, "A Novel Three-Phase Hybrid Active Power Filter With a Series Resonance Circuit Tuned at the Fundamental Freque," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2431-2440, July 2009. Abstract Link Full Text Abstract: In this paper, a novel three-phase hybrid active power filter (HAPF) with a series resonance circuit tuned at the fundamental frequency is proposed for simultaneously suppressing harmonic currents and compensating high-capacity reactive power in high- or medium-voltage power systems. To reduce its rated capacity, the active power filter is shunted to the series resonance circuit by a matching transformer and, thus, greatly reduces its current requirements as well as voltage ratings of semiconductor switching devices. The passive power filters are used to compensate the reactive power with a constant capacity. The validity and effectiveness of this novel HAPF system have been verified by simulation and industrial application results. Machines and Drives
56.7.17	A. Das, K. Sivakumar, R. Ramchand, C. Patel, K. Gopakumar, "A Pulsewidth Modulated Control of Induction Motor Drive Using Multilevel 12-Sided Polygonal Voltage Space Vect," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2441-2449, July 2009. Abstract Link Full Text Abstract: In this paper, a novel 12-sided polygonal space vector structure is proposed for an induction motor drive. The space vector pattern presented in this paper consists of two 12-sided concentric polygons with the outer polygon having a radius double the inner one. As compared to previously reported 12-sided polygonal space vector structures, this paper subdivides the space vector plane into smaller sized triangles. This helps in reducing the switching frequency of the inverters without deteriorating the output voltage quality. It also reduces the device ratings and $dnu/ dt$ stress on the devices to half. At the same time, other benefits obtained from the existing 12-sided space vector structure, such as increased linear modulation range and complete elimination of 5th and 7th order harmonics in the phase voltage, are also retained in this paper. The space vector structure is realized by feeding an open-end induction motor with two conventional three-level neutral point clamped (NPC) inverters with asymmetric isolated dc link voltage sources. The neutral point voltage fluctuations in the three-level NPC inverters are eliminated by utilizing the switching state multiplicities for a space vector point. The pulsewidth modulation timings are calculated using sampled reference waveform amplitudes and are explained in detail in this paper. Experimental verification on a laboratory prototype shows that this configuration may be considered suitable for high power drives.
56.7.18	F. J. Rodriguez, C. Giron, E. J. Bueno, A. Hernandez, S. Cobreces, P. Martin, "Remote Laboratory for Experimentation With Multilevel Power Convert," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2450-2463, July 2009. Abstract Link Full Text Abstract: This paper describes the hardware and software modules of a remote Internet-based laboratory for experimentation with a 120-kVA multilevel power converter. The key feature of this laboratory is the utilization of a multilevel converter that can be controlled and supervised remotely in a secured way. A wide variety of laboratory experiments are supported, from grid connection to ac motor control. Users can choose the control structure, the control parameters, and the kind of load and get the graphical results of the measurements, all in real time. Single-Phase Electronics
56.7.19	S. Borekci, "Dimming Electronic Ballasts Without Striati," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2464-2468, July 2009. Abstract Link Full Text Abstract: Power density modulation control strategy is proposed for eliminating the striations in dimming applications. In a modulation period, the lamp is operated in several states. For any desired lamp power, the fluorescent lamp current requirement must be met in one of the states. A prototype dimmable electronic ballast is built and experimented. As result, a 36WT8 fluorescent lamp is driven within wide power range from 2 W to full without striation.
56.7.20	J.-J. Chen, F.-C. Yang, C.-C. Lai, Y.-S. Hwang, R.-G. Lee, "A High-Efficiency Multimode Li–Ion Battery Charger With Variable Current Source and Controlling Previous-Stage Supply Volt," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2469-2478, July 2009. Abstract Link Full Text Abstract: A high-efficiency multimode Li–Ion battery charger with variable current source and controlling previous-stage supply voltage is presented in this paper. Using variable current source can achieve the goal of constant-current mode to charge the battery and control previous-stage supply voltage which could increase the efficiency of the multimode battery charger. Moreover, the charging mode adopted in this charger is applied by two types of dual-mode strategy decided by the value of the equivalent series resistance of the Li–Ion battery. This technique will reduce the damage of Li–Ion battery. The Li–Ion battery charger is designed with 0.35-$muhbox{m}$ CMOS double-poly four-metal processes. The experimental results show that the charger works well and the theoretical analysis can be confirmed. The average power efficiency of the multimode Li–Ion battery charger can be up to 91.2% under the average power of 1.24 W, and the accuracy of the adaptive reference voltage is up to 97.3%. The chip area is only $1.32 times 0.95 hbox{mm}^{2}$.
56.7.21	B. P. Divakar, K. W. E Cheng, D. H. Wang, D. Ping, K. F. Kwok, "Implementation of a Voltage Multiplier Integrated HID Ballast Circuit With Dimming Control for Automotive Applicat," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2479-2492, July 2009. Abstract Link Full Text Abstract: High-intensity discharge (HID) lamps are becoming popular substitutes for halogen lamps in automotive headlamps because of the high lumen/watt ratio and the color of the light. In this paper, a ballast (integrated with a voltage multiplier circuit in the secondary winding of the dc converter transformer) with dimming control is presented. The proposed circuit not only eliminates one auxiliary winding but also reduces the voltage across the switch on the primary side and consequently permits the selection of switches with a lower rating. A brief review of the HID circuits is done and compared with the proposed circuit. Experimental results from the prototype are presented. This paper also presents different methods of dimming the automotive HID lamps based on analog and digital control and discusses the relative merits of each of the methods. The dimming control is implemented using both the methods, and experimental results are presented. It is envisaged that the dimming control will provide some flexibility to drivers in the control of HID lamps to suit the driving conditions in the modern cities that are very well lit at night. This paper investigates the merits of each method and discusses the practical issues for implementing such controls.
56.7.22	K. H. Kwan, Y. C. Chu, P. L. So, "Model-Based $hbox{H}_{infty}$ Control of a Unified Power Quality Conditio," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2493-2504, July 2009. Abstract Link Full Text Abstract: This paper presents a solution to the control of a unified power quality (PQ) conditioner (UPQC) for PQ improvement in power distribution systems. The problem formulation allows not only harmonic compensation but also voltage sags/swells, load demand changes, and power factor correction to be tackled in a unified framework. The proposed controller combines the multivariable regulator theory with $hbox{H}_{ infty}$ loop shaping, so that zero steady-state error, robustness to modeling uncertainties, and insensitivity to supply frequency variations can be accomplished simultaneously, thus providing a complete theoretical solution to all the aforementioned PQ problems. The effectiveness of the proposed controller is, in practice, verified by experimental studies on a single-phase power distribution system.
56.7.23	S.-S. Lee, S.-W. Rhee, G.-W. Moon, "Coupled Inductor Incorporated Boost Half-Bridge Converter With Wide ZVS Operation Ra," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2505-2512, July 2009. Abstract Link Full Text Abstract: A new boost half-bridge (BHB) converter is presented. It is composed of an additional diode and a coupled winding to the boost inductor of the BHB converter. Using the transferring of a boost inductor current to the coupled winding, the cancellation of zero-voltage-switching (ZVS) current, which always occurs in a conventional one, is prevented. Therefore, the ZVS operation is easily achieved by the leakage inductor current of the transformer. Furthermore, since the negatively built-up leakage inductor current of the boost winding helps the ZVS operation throughout a wide load range, the ZVS operation is always guaranteed.
56.7.24	S. Vazquez, J. I. Leon, L. G. Franquelo, J. J. Padilla, J. M. Carrasco, "DC-Voltage-Ratio Control Strategy for Multilevel Cascaded Converters Fed With a Single DC Sou," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2513-2521, July 2009. Abstract Link Full Text Abstract: Recently, a multilevel cascaded converter fed with a single dc source has been presented. An analysis of the steady-state working limits of this type of converter is presented in this paper. Limits of the maximum output voltage and the minimum and maximum loading conditions for stable operation of the converter are addressed. In this paper, a way to achieve any dc voltage ratio (inside the stable operation area of the converter) between the H-bridges of the single-dc-source cascaded H-bridge converter is presented. The proposed dc-voltage-ratio control is based on a time-domain modulation strategy that avoids the use of inappropriate states to achieve the dc-voltage-ratio control. The proposed technique is a feedforward-modulation technique which takes into account the actual dc voltage of each H-bridge of the converter, leading to output waveforms with low distortion. In this way, the dc voltage of the floating H-bridge can be controlled while the output voltage has low distortion independently of the desired dc voltage ratio. Experimental results from a two-cell cascaded converter are presented in order to validate the proposed dc-voltage-ratio control strategy and the introduced concepts.
56.7.25	P.-J. Liu, H.-J. Chiu, Y.-K. Lo, Y.-J. E. Chen, "A Fast Transient Recovery Module for DC–DC Convert," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2522-2529, July 2009. Abstract Link Full Text Abstract: This paper presents a novel fast transient recovery module to improve the transient response of dc–dc converters to meet the challenging power supply requirement of fast dynamic load changes. The current-pump module operates only at transient state to provide additional current injection and current drain for step-up and step-down loads, respectively. The dual-mode control is proposed to switch the voltage control mode of dc–dc converters to hysteretic control mode during transient. The measurement results show that the fast transient recovery module and dual-mode control can improve the recovery time of dc–dc converters by more than an order.
56.7.26	N. D. Patel, U. K. Madawala, "A Bit-Stream-Based PWM Technique for Sine-Wave Generat," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2530-2539, July 2009. Abstract Link Full Text Abstract: A new method for the generation of high-quality sinusoidal signals is presented. Multibit binary signals are represented using uniformly weighted single bit streams that can then be processed by digital logic. Building blocks that are useful for the construction of the sinusoidal generator are also presented. The bit-stream representation has the advantage of having the characteristics of a classical pulsewidth-modulation signal and hence can be used to drive high-power switching devices with minimal conditioning. The technique is simple and can easily be implemented using digital logic on a field-programmable gate array (FPGA). The operation of a single-phase inverter using the proposed technique is demonstrated using an Altera Stratix FPGA and a custom-built power stage. The complete digital design uses less than 200 logic elements. The performance of this technique is quantified using simulations and practical measurements. Practical implementations lead to total harmonic distortion measures ranging between 0.75% and 4.92%.
56.7.27	M. Mahdavi, H. Farzanehfard, "Zero-Current-Transition Bridgeless PFC Without Extra Voltage and Current Str," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2540-2547, July 2009. Abstract Link Full Text Abstract: In this paper, a new zero-current-switching high-power-factor (PF) rectifier with pulsewidth-modulation control is introduced. The auxiliary circuit provides soft switching for all semiconductor devices without any extra current and voltage stress on the main switches. The proposed converter is bridgeless, and all semiconductor devices are soft switched. In addition, there is no extra stress on the switches. Thus, the conduction and switching losses are reduced and maximum efficiency is achieved. The converter is designed and simulated, and a prototype is implemented to verify the system performance. The experimental results exhibit high PF and efficiency of the proposed converter.
56.7.28	C. Olalla, R. Leyva, A. El Aroudi, I. Queinnec, "Robust LQR Control for PWM Converters: An LMI Appro," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2548-2558, July 2009. Abstract Link Full Text Abstract: A consistent framework for robust linear quadratic regulators (LQRs) control of power converters is presented. Systems with conventional LQR controllers present good stability properties and are optimal with respect to a certain performance index. However, LQR control does not assure robust stability when the system is highly uncertain. In this paper, a convex model of converter dynamics is obtained taking into account uncertainty of parameters. In addition, the LQR control for switching converters is reviewed. In order to apply the LQR control in the uncertain converter case, we propose to optimize the performance index by using linear matrix inequalities (LMIs). As a consequence, a new robust control method for dc–dc converters is derived. This LMI-LQR control is compared with classical LQR control when designing a boost regulator. Performance of both cases is discussed for load and line perturbations, working at nominal and nonnominal conditions. Finally, the correctness of the proposed approach is verified with experimental prototypes.
56.7.29	T. Nussbaumer, K. Raggl, J. W. Kolar, "Design Guidelines for Interleaved Single-Phase Boost PFC Circu," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2559-2573, July 2009. Abstract Link Full Text Abstract: This paper provides a comprehensive guideline for the design of a single-phase PFC targeting for minimal volume, as it is highly relevant for ultracompact integrated systems. It is shown, how different operation modes (continuous, boundary, and discontinuous conduction mode) may influence the design and consequently the achieved power density. Furthermore, the effect of interleaving of several boost stages is analyzed as a measure for compactness increase. Finally, the selection of the appropriate switching frequency in order to achieve an overall optimized system is discussed. In this way, the design of the crucial components is carried out, namely, the boost inductor, including a volume optimization through a thermal connection to the heat sink; the output capacitor considering the rms current stress; and the input filter, which is designed for compliance with high-frequency electromagnetic compatibility standards, taking into account the quasi-peak detection measurement of the test receiver equipment.
56.7.30	K. Raggl, T. Nussbaumer, G. Doerig, J. Biela, J. W. Kolar, "Comprehensive Design and Optimization of a High-Power-Density Single-Phase Boost ," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2574-2587, July 2009. Abstract Link Full Text Abstract: The design of a single-phase boost power-factor-correction (PFC) circuit is associated with a large variety of considerations, such as the following questions. Which operation mode should be selected (e.g., continuous or discontinuous operation)? How many interleaved boost cells are advantageous? Which switching frequency should be selected? What is the optimum number of EMI input filter stages? Which semiconductor technology should be chosen? All these issues have a significant influence on the converter efficiency and power density. In this paper, the aforementioned questions are addressed for exemplary specifications of the PFC (300-W output power, 400-V output voltage, and 230-V mains voltage), whereby the focus in the design is mainly put on very high power density. As a result, different design points are identified and comparatively evaluated. By considering different aspects such as volume, losses, capacitor lifetime, and also cost issues (e.g., by additional current sensors or expensive silicon carbide devices), a dual-interleaved PFC operated in discontinuous conduction mode at 200 kHz is selected. With an experimental prototype, a superior power density of 5.5 kW/L and a system efficiency of 96.4% are achieved, which is close to the values predicted by the design procedure. Furthermore, measurements verify a near-unity power factor $(hbox{PF} = 99.7%)$ and the compliance with electromagnetic compatibility conducted noise emission standards. Finally, it is investigated to which extent the power density could be further increased by an integration of the input filter in the PCB.
56.7.31	S. A. Saleh, C. R. Moloney, M. A. Rahman, "Development and Testing of Wavelet Modulation for Single-Phase Invert," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2588-2599, July 2009. Abstract Link Full Text Abstract: This paper introduces a novel modulation technique for single-phase $(1 phi)$ voltage-source (VS) dc–ac power inverters. The proposed modulation technique is based on a newly designed scaling function that is capable of supporting a nonuniform recurrent sampling process. This scaling function generates sets of basis functions that span spaces, of which a collection constructs a nondyadic-type multiresolution analysis. Furthermore, the newly designed scaling function has a dual synthesis scaling function that is designed to reconstruct continuous-time signals from their nonuniform recurrent samples. The proposed wavelet modulation technique is implemented using a MATLAB code that generates switching pulses to activate a SIMULINK model of a $1phi$ VS four-pulse ( $H$-bridge) inverter. Several performance tests are conducted for the proposed wavelet-modulated (WM) inverter, when supplying linear, nonlinear, static, and dynamic loads. The results of these tests show significant reduction of the output harmonics along with high magnitude of the output fundamental component. The efficacy of the proposed WM inverter is further demonstrated through a comparison of the random pulsewidth modulation (RPWM) and the pulsewidth modulation (PWM) inverters for supplying the same loads. The comparison results show that the proposed WM inverter is capable of producing outputs with higher quality than the RPWM and PWM inverters.
56.7.32	T. Shimizu, S. Iyasu, "A Practical Iron Loss Calculation for AC Filter Inductors Used in PWM Invert," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2600-2609, July 2009. Abstract Link Full Text Abstract: A novel iron loss calculation method is proposed based on an iron loss map for an ac filter inductor used in a pulsewidth-modulation (PWM) inverter. The iron loss map, previously reported by the authors, is created by measuring the dynamic minor loop on the $B$– $H$ plane, and this is used for the calculation of inductor iron loss in the dc chopper circuit. However, in the case of an ac filter inductor used in a PWM inverter, the iron loss map cannot be directory applied to the iron loss calculation. In this paper, an iron loss calculation for an ac filter inductor is presented by expanding the loss map method. We describe the principle of expansion and the practical procedure for the calculation, which utilizes the loss map and a conventional circuit simulator. Iron loss for the ac filter inductor under some typical modulation methods of the PWM inverter are calculated and discussed with regard to the relation between the modulation methods and iron loss. The calculated results are verified using experimental results from a 500-W inverter setup. The inductor loss and conversion efficiency of the PWM inverter are measured for each modulation method.
56.7.33	R. Stala, S. Pirog, M. Baszynski, A. Mondzik, A. Penczek, J. Czekonski, S. Gasiorek, "Results of Investigation of Multicell Converters With Balancing Circuit—Par," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2610-2619, July 2009. Abstract Link Full Text Abstract: This paper presents the results of an investigation of the multilevel multicell converters with a passive $RLC$ balancing circuit applied for the maintenance of the voltage sharing on the capacitive sources of the converters. The topologies of dc/dc, ac/ac, dc/ac, and ac/dc multicell converters were analyzed. For the purpose of multilevel modulation, a multicell converter employs several capacitors that are connected to every cell—the flying capacitors, charged to a given level of voltage. An inadequate relation between the voltages across the flying capacitors (the unbalance state) results in the increase of the voltages above their rated values across the switches. An $RLC$ series circuit (a balancing circuit) with the properly selected resonance frequency is connected in parallel to the load in order to eliminate the unbalance. The balancing process with the use of passive $RLC$ depends on the configuration and parameters of the balancing circuit, the parameters of the converter, as well as on the operating conditions. This paper presents the mathematical description of both the converter and the balancing process, the balancing circuit approach in the different topologies of the multicell converters, a selection of the balancing circuit parameters, and the analysis of the improper control conditions.
56.7.34	R. Stala, S. Pirog, A. Mondzik, M. Baszynski, A. Penczek, J. Czekonski, S. Gasiorek, "Results of Investigation of Multicell Converters With Balancing Circuit—Part," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2620-2628, July 2009. Abstract Link Full Text Abstract: This paper presents an investigation of a multilevel multicell ac/ac converter. The converter employs flying capacitors, whose voltages should remain in a constant relation to the input ac voltage. An inadequate relation between the voltages across the flying capacitors (the imbalance state) results in an increase of voltages across the switches above their rated values. An RLC series circuit (a balancing circuit) with a properly selected resonance frequency was connected in parallel to the load in order to eliminate the imbalance. The balancing process with the use of a passive RLC depends on the configuration and parameters of the balancing circuit, the parameters of the converter, as well as on the operating conditions. This paper focuses on the impact of these parameters on the operation of the converter. Furthermore, the principle of operation of the multilevel multicell ac/ac converter with an application of the natural balancing process is described. Renewable Energy Systems
56.7.35	R.-J. Wai, C.-Y. Lin, Y.-R. Chang, "High Step-Up Bidirectional Isolated Converter With Two Input Power Sour," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2629-2643, July 2009. Abstract Link Full Text Abstract: The objective of this paper is to develop a high step-up isolated converter with two input power sources. The proposed converter has two input ports for simultaneously converting two different input power sources with low voltages to a stable output power with a high voltage. Moreover, the demand of bidirectional power flow, which is dependent on the power management for charging and discharging power storage mechanisms, can also be satisfied in the proposed converter. According to various situations, the operational states of the proposed converter can be divided into three states, including a stand-alone state, a united power supply state, and a charge and discharge state. The effectiveness of the designed circuit topology is verified by experimental results, and the goals of high-efficiency conversion, high step-up ratio, and bidirectional power flow can be achieved by the proposed converter operation. Robotics and Mechatronics
56.7.36	A. Bellini, M. Colli, E. Dragoni, "Mechatronic Design of a Shape Memory Alloy Actuator for Automotive Tumble Flaps: A Case St," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2644-2656, July 2009. Abstract Link Full Text Abstract: The continuous advance in mechatronics has long attracted researchers toward the development of new highly integrated actuators for automotive applications where reduced space and low weight are common constraints. In this context, Shape Memory Alloys (SMAs) offer many peculiar characteristics that make this technology very attractive for the construction of miniature mechatronic actuators. This paper presents the design, the prototype fabrication, and the functional testing of a case study, where an SMA binary actuator is used for automotive tumble flaps. The innovative solid-state actuation system is proposed as an alternative to electromagnetic and pneumatic effectors, traditionally used to drive the tumble shaft of an air intake manifold for internal combustion engines. Original features of the linear actuator involve the mechanical architecture and the control structure. On the mechanical side, two contrasting sets of SMA springs are used to actively generate the net actuating force during both outstroke and instroke. On the control side, a current feedback is exploited for sensorless real-time monitoring of the working temperature of the SMA springs during electrical supply. Major shortcomings of the proposed solution are a low response time and a power consumption higher than pneumatic and electromagnetic counterparts.
56.7.37	M. Probst, M. Fluckiger, S. Pane, O. Ergeneman, Z. Nagy, B. J. Nelson, "Manufacturing of a Hybrid Acoustic Transmitter Using an Advanced Microassembly Sys," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2657-2666, July 2009. Abstract Link Full Text Abstract: Advances in both capabilities and miniaturization of medical devices offer promising prospects for medical treatments. Applications range from simple diagnosis to complex treatment tools. Miniature untethered robotic devices are playing a central role within this growing trend, and devices are becoming available on the market. However, one of the biggest challenges is the localization of these devices within the human body in order to close the control loop. This paper presents the design and fabrication of a novel device for localization based on acoustic transducers. The individual microfabricated MEMS components are assembled using a state-of-the-art 6-DOF micromanipulation system in order to meet the high-precision requirements. First position determination experiments have successfully proven the concept with results on the order of submillimeters.
56.7.38	R.-J. Wai, C.-M. Liu, "Design of Dynamic Petri Recurrent Fuzzy Neural Network and Its Application to Path-Tracking Control of Nonholonomic Mobile Ro," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2667-2683, July 2009. Abstract Link Full Text Abstract: This paper focuses on the design of a dynamic Petri recurrent fuzzy neural network (DPRFNN), and this network structure is applied to the path-tracking control of a nonholonomic mobile robot for verifying its validity. In the DPRFNN, the concept of a Petri net and the recurrent frame of internal-feedback loops are incorporated into a traditional FNN to alleviate the computation burden of parameter learning and to enhance the dynamic mapping of network ability. Moreover, the supervised gradient-descent method is used to develop the online-training algorithm for the DPRFNN control. In order to guarantee the convergence of path-tracking errors, analytical methods based on a discrete-type Lyapunov function are proposed to determine varied learning rates for DPRFNN. In addition, the effectiveness of the proposed DPRFNN control scheme under different moving paths is verified by experimental results, and its superiority is indicated in comparison with FNN, RFNN, Petri FNN, and PRFNN control systems. Signal Processing and Control
56.7.39	C. Canudas-de-Wit, F. Gomez-Estern, F. R. Rubio, "Delta-Modulation Coding Redesign for Feedback-Controlled Syst," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2684-2696, July 2009. Abstract Link Full Text Abstract: This paper investigates the closed-loop properties of the differential coding scheme known as Delta-modulation ($Delta$-$M$) when used in feedback loops within the context of feedback-controlled systems. We propose a new modified scheme of the original form of the $Delta$- $M$ algorithm which is better suited for applications where the sensed information is used in feedback. A state feedback controller is implemented with the state estimated by a predictor-based differential decoder. Stability of the resulting closed-loop system (controller–coder–decoder) is studied. These properties (stability and performance) depend on the quantization parameter $ Delta$, which is assumed constant in the first part of this paper. In a further step, parameter $Delta$ is made adaptive, by defining an adaptation law exclusively in terms of information available at both the transmitter and receiver side. With this approach both stability and performance is improved.
56.7.40	P. Lezana, G. Ortiz, "Extended Operation of Cascade Multicell Converters Under Fault Condit," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2697-2703, July 2009. Abstract Link Full Text Abstract: Multilevel converters are an interesting alternative for high power drives, due to their good quality output signals. Despite their advantages, the large number of components required increases the fault probability. Among the multilevel topologies, the cascade multicell converter presents advantages when operating under internal fault conditions, due to its high modularity. Previous works proposed to compensate the unbalanced operation due to a fault by changing the canonical fundamental output phase shift to precalculated angles, depending on the fault condition. This solution assumes that, if the maximum output phase voltage on each leg is used, the maximum line-to-line voltage will be at a maximum as well. This paper shows how this assumption is not always valid and presents the optimum angles and modulation indexes that must be used in order to obtain the maximum balanced load voltages.
56.7.41	Y.-X. Liao, J.-H. She, M. Wu, "Integrated Hybrid-PSO and Fuzzy-NN Decoupling Control for Temperature of Reheating Furn," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2704-2714, July 2009. Abstract Link Full Text Abstract: This paper presents an integrated method of intelligent decoupling control as a solution to the problem of adjusting the zone temperatures in a regenerative pusher-type reheating furnace. First, a recurrent neural network (NN) for estimating the zone temperatures and a heat transfer model for predicting billet temperatures are built based on data from actual furnace operations. Next, a decoupling strategy in combination with a fuzzy NN is used to control the zone temperatures. The architecture of the controller is based on a fuzzy c-means clustering approach; and the weights are optimized by a hybrid particle swarm optimization (HPSO) algorithm, which integrates the global optimization of density-based selection and the precise search of clonal expansion in an immune system with the fast local search of particle swarm optimization. HPSO is also used to optimize the zone temperature settings to minimize three items: fuel consumption, the temperature gradient within a billet, and the error between the mean and target temperatures of a billet at the furnace exit. The results of actual runs demonstrate the validity of this method.
56.7.42	F. Morel, X. Lin-Shi, J.-M. Retif, B. Allard, C. Buttay, "A Comparative Study of Predictive Current Control Schemes for a Permanent-Magnet Synchronous Machine Dr," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2715-2728, July 2009. Abstract Link Full Text Abstract: This paper presents a comparative study of three predictive current control schemes for permanent-magnet synchronous machine (PMSM) drives. The first control scheme predicts the future evolution of the currents for each possible configuration of the inverter legs. Then, the switching state which minimizes a given cost function is selected and applied during the next sampling time. The second control scheme uses a modulator to apply two configurations of the inverter legs during a computation period. Among these configurations, one leads to null voltages. The duration of the other configuration is calculated in order to minimize the distance between the obtained state vector and the desired one. The third control scheme uses a model of the PMSM in order to predict the stator voltages which allows us to reach the desired currents after one modulation period. An algebraic method is presented to compute the duty cycle of each leg of the inverter in a direct manner. These control schemes are detailed and tested using the same switching frequency on the same test bench (1.6-kW PMSM drive). A simulation study is performed in order to compare sensitivity to parameters of each control scheme. Experiments confirm the simulation results.
56.7.43	A. Santolaria, "Effects of Switching Frequency Modulation on the Power Converter's Output Volt," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2729-2737, July 2009. Abstract Link Full Text Abstract: Frequency modulation of the switching signal controlling the electromagnetic interference (EMI) performance of a switching power converter (SPC) is a quite well-known theme that has been previously discussed. Generic Spread Spectrum Clock Generation methods have been theoretically analyzed and finally applied to an SPC's emissions reduction (whereas the previous real applications were focused on digital signals operated by a clock line). From this point of view, a more general denomination of these methods is necessary and Spread Spectrum Switching Generation is here proposed. Effects on EMI emissions reduction are clearly worthy when selecting the modulation parameters in a convenient way. However, most references are focused on reducing the EMI emissions generated by the SPC without taking into account the influence of such frequency modulation methods on the output voltage of the power supply. This paper aims at this point because, in fact, this is the main purpose of a power converter: supplying energy at an ideally constant voltage. Continuous conduction mode of a buck converter is theoretically studied and compared to the practical results obtained from a real power supply. In a first approximation, open-loop configuration was selected as the operation mode before closing the loop, where influence of the modulation is also present but is much more complicated to analyze.
56.7.44	B. Singh, J. Solanki, "A Comparison of Control Algorithms for DSTAT," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2738-2745, July 2009. Abstract Link Full Text Abstract: In this paper, a Distribution STATic COMpensator (DSTATCOM) is proposed for compensation of reactive power and unbalance caused by various loads in distribution system. An evaluation of three different methods is made to derive reference currents for a DSTATCOM. These methods are an instantaneous reactive power theory, a synchronous reference frame theory, and a new Adaline-based algorithm. The Adaline-based algorithm is an adaptive method for extracting reference current signals. These schemes are simulated under MATLAB environment using SIMULINK and PSB toolboxes. Simulation and experimental results demonstrate the performance of these schemes for the control of DSTATCOM.
56.7.45	D. Wu, K. Chen, "Design and Analysis of Precision Active Disturbance Rejection Control for Noncircular Turning Proc," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2746-2753, July 2009. Abstract Link Full Text Abstract: In this paper, a new fast tool servocontrol method for noncircular turning process (NCTP) is presented. Based on the tracking and disturbance rejection requirements for NCTP, the controller is designed through a combined active disturbance rejection control and feedforward arrangement by exploiting the unique disturbance estimation and compensation concept and the known reference acceleration signals. In such a design framework, an extended state observer is applied to estimate and compensate for the variant dynamics of the system, nonlinearly variable cutting load, and other uncertainties. Then, a simple proportional integral controller and the acceleration feedforward design produce the control law. To quantify the controller performances, the transfer function description of the controller is derived, and the dynamic stiffness and tracking have been analyzed. By defining the vector margin variation rate, the effects of the plant parameter variations on closed-loop stability are also addressed. Experimental results of machining the first- and second-order oval profiles demonstrate that the tracking error is less than 3 $muhbox{m}$ for different cutting parameters. Diagnosis and Monitoring
56.7.46	T.-J. Kim, W.-C. Lee, D.-S. Hyun, "Detection Method for Open-Circuit Fault in Neutral-Point-Clamped Inverter Syst," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2754-2763, July 2009. Abstract Link Full Text Abstract: This paper presents a fault detection method for open-circuit faults of a switching device in neutral-point-clamped inverter systems, which is based on the inherent characteristic of continuous pulsewidth modulation. The proposed method is achieved by measuring the pole voltage and its duration time. The pole voltage includes information of switching states in the inverter system but not affected by the load. Therefore, a fault condition of the inverter system itself can be diagnosed through analysis of pole voltage. Compared to conventional fault detection methods, the proposed fault detection method has faster detection capability that is within two sampling times and is much simpler to implement. Therefore, the use of the proposed method could minimize harmful effects such as imbalance of dc-link voltage and overstress on other switching devices. The validity of the proposed fault detection method is verified through experimental results.
56.7.47	Z. Zhao, F.-L. Wang, M.-X. Jia, S. Wang, "Intermittent-Chaos-and-Cepstrum-Analysis-Based Early Fault Detection on Shuttle Valve of Hydraulic Tube Tes," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2764-2770, July 2009. Abstract Link Full Text Abstract: To ensure the safety and continuity of production, make a reasonable maintenance plan, and save the cost of maintenance for a hydraulic tube tester, it is needed to quickly identify an assignable cause of a fault. This paper is concerned with early fault detection of shuttle valves, which are the key components in hydraulic tube tester. An intermittent-chaos-and-cepstrum-analysis-based method is proposed to detect this early fault on the hydraulic tube tester. The presented approach is based on the insight that the phase transition of Duffing oscillator is very sensitive to a periodic weak signal having tiny angular frequency difference with the reference signal in this oscillator. Thus, to determine the angular frequency of the reference signal, cepstrum analysis is used to determine the eigenfrequency of the fault signal, and then, the angular frequency of the referential signal is computed according to this eigenfrequency. Finally, a Lyapunov exponent is introduced to realize computer observation of the shuttle valve early fault. The presented method is experimented with data simulated from an AMESim model of hydraulic tube tester. The results indicate that the proposed approach is capable of detecting the signal of shuttle valve early fault in the hydraulic tube tester. Instrumentation and Sensors
56.7.48	J.-U. W. Hsu, A. P. Hu, A. Swain, "A Wireless Power Pickup Based on Directional Tuning Control of Magnetic Amplif," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2771-2781, July 2009. Abstract Link Full Text Abstract: This paper proposes a novel inductor–capacitor–inductor wireless power pickup with directional tuning control (DTC) for a magnetic amplifier. The proposed technique allows the power pickup to achieve full-range tuning/detuning operation to regulate power flow and maintain the output voltage to be constant. The method eliminates the tedious fine-tuning process associated with traditional fixed power pickup tuning methods and eases the component selection. Moreover, it can overcome the online circuit parameter variations and automatically achieve the maximum power transfer capacity when required. In order to meet dynamic load demands, a magnetic amplifier is used as a variable inductor and is controlled by a novel DTC algorithm to change the tuning condition of the power pickup. The effectiveness of the proposed power pickup and its applicability to general wireless power transfer applications have been demonstrated by both simulation and experimental results. Intelligent Systems
56.7.49	M. Wu, J. Yan, J.-H. She, W.-H. Cao, "Intelligent Decoupling Control of Gas Collection Process of Multiple Asymmetric Coke Ov," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2782-2792, July 2009. Abstract Link Full Text Abstract: This paper presents a hierarchical intelligent decoupling control method for the gas collection process of three asymmetric coke ovens of an iron and steel company. The process features strong asymmetric coupling, large disturbances, and strong nonlinearity. These characteristics are exploited in the following steps to implement intelligent decoupling control. First, three fuzzy expert controllers and two feedforward controllers stabilize the pressure of each gas collector. Then, the three collectors are divided into two groups based on an analysis of the couplings among them to facilitate decoupling control. An intelligent decoupling control method is used to design intragroup and intergroup decoupling controllers. Finally, expert valve control handles the nonlinearity of butterfly valves, and a multirate sampling strategy further improves the control performance. The results of actual runs show that the system satisfactorily performs the intelligent decoupling control of the gas pressures of the coke ovens, sufficiently suppresses disturbances, and accurately stabilizes the pressures. Letters
56.7.50	H.-J. Chiu, Y.-K. Lo, T.-P. Lee, S.-C. Mou, H.-M. Huang, "Design of an RGB LED Backlight Circuit for Liquid Crystal Display Pan," IEEE Trans. on Industrial Electronics, vol. 56, no. 7, pp. 2793-2795, July 2009. Abstract Link Full Text Abstract: This paper presents a red, green, and blue (RGB) light-emitting diode (LED) backlight circuit for liquid crystal display (LCD) panels. Some studies have been conducted to devise dimming methods that regulate the RGB LED currents. In this paper, design considerations for the RGB LED backlight are presented. A laboratory prototype for 20-in panels is implemented and tested. The color gamut of an LCD panel with the designed RGB LED backlight is measured and discussed. The experimental results of the laboratory prototype are also shown to verify feasibility of the findings.