Publications
Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleHui SY, Chung HSH, Tang SC, 1999,
Coreless printed circuit board (PCB) transformers for power MOSFET/IGBT gate drive circuits
, IEEE Transactions on Power Electronics, Vol: 14, Pages: 422-430, ISSN: 0885-8993Gate drive circuits for modern power electronic switches, such as MOSFET and insulated gate bipolar transistor (IGBT), often require electrical isolation. This paper describes the modeling and experimental results of some coreless printed circuit board (PCB)-based transformers that can be used for MOSFET and IGBT devices at high-frequency (500 kHz to 2 MHz) operation. PCB-based transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits. With no core loss, coreless transformers are found to have favorable characteristics at high-frequency operations. This project demonstrates an important point that the size of the magnetic core can approach zero and become zero when the frequency is sufficiently high.
-
Journal articleHui SYR, Chung H, 1999,
Paralleling power converters for AC-DC step-down power conversion with inherent power factor correction
, IEE Proceedings: Electric Power Applications, Vol: 146, Pages: 247-252, ISSN: 1350-2352The authors describe the modular development of a single-stage AC-DC step-down power converter. The converter offers advantages such as simple DC-DC type switching control, electrically isolated output and inherent power factor correction. It also provides single-stage power conversion without using power devices with excessively high voltage and current rating, the flexibility for expansion of power capability, and a simplification of design and production procedure for the manufacturing of power converter products. The operating modes of the converter are described and analyzed. Experiments have confirmed the validity of the modular converter operation.
-
Journal articleHui SY, Tang SC, Chung HSH, 1999,
Optimal operation of coreless PCB transformer-isolated gate drive circuits with wide switching frequency range
, IEEE Transactions on Power Electronics, Vol: 14, Pages: 506-514, ISSN: 0885-8993Gate drive circuits for power MOSFET's and insulated gate bipolar transistors (IGBT's) often require electrical isolation. Coreless printed circuit board (PCB) transformers have been shown to have desirable characteristics from a few hundreds of hertz to a few megahertz and can be used for both power and signal transfer at low-power level. At low operating frequency, the magnetizing inductance has such low impedance that the driving power requirement could become excessive. This paper describes the use of a coreless PCB transformer for isolated gate drive circuits over a wide-frequency range. Based on a resonance concept, the optimal operating condition that minimizes the power consumption of the gate drive circuits is developed and verified with experiments. The coreless PCB transformer demonstrated here confirms a fundamental concept that the size and volume of a magnetic core could approach zero and become zero if the operating frequency is sufficiently high. Coreless PCB transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits and low-power converters. Their sizes can be much smaller than those of typical core-based pulse transformers. The electrical isolation of a PCB is much higher than that of an optocoupler.
-
Conference paperAstolfi A, Laiou C, Mazenc F, 1999,
New results and examples on a class of discontinuous controllers
, European Control Conference, Karlsruhe, Germany -
Journal articleFerreira M, Fontes F, Vinter RB, 1999,
Nondegenerate Necessary Conditions for Nonconvex Optimal Control Problems with State Constraints
, Journal of Mathematical Analysis and Applications -
Journal articleScokaert POM, Mayne DQ, Rawlings JB, 1999,
Suboptimal model predictive control (feasibility implies stability)
, IEEE Trans.Automatic Control, Vol: 44, Pages: 648-654 -
Conference paperAntonelli R, Astolfi A, 1999,
Adaptive output feedback stabilization of a class of uncertain continuous stirred tank reactors
, 14th IFAC World Congress, Beijing, China -
Conference paperMuthu R, Green TC, Frankland JD, 1999,
DC uninterruptable power supply topologies
, Universities Power Engineering Conference 1999, Pages: 411-414 -
Journal articleAstolfi A, 1999,
Exponential stabilization of a wheeled mobile robot
, ASME, Journal of Dynamic Systems Measurement and Control, Vol: 121, Pages: 121-126 -
Conference paperMazenc F, Astolfi A, Lozano R, 1999,
Lyapunov Function for the Ball and Beam: Robustness Property
, 38th Conference on Decision and Control, Phoenix, AZ -
Journal articleAllwright JC, 1999,
Orthogonal Lyapunov transformations with some applications to stability studies
, IEE Proc.Control Theory and Applications, Vol: 146, Pages: 333-340 -
Conference paperGreen TC, Newton A, Andrew D, 1999,
Choice of Converter Topologies and Power Distribution Topologies Within Process Plants
, Universities Power Engineering Conference, Pages: 316-319 -
Conference paperLaiou C, Astolfi A, 1999,
Quasi smooth control of chained systems
, American Control Conference, San Diego, CA -
Journal articleAstolfi A, 1999,
Output feedback stabilization of the angular velocity of a rigid body
, Systems and Control Letters, Vol: 36, Pages: 181-192 -
Conference paperAntonelli R, Astolfi A, 1999,
Output feedback regulation for nonlinear chemical processes with input constraints
, Aiche Annual Meeting, Dallas, 1999 -
Book chapterAstolfi A, Menini L, 1999,
Further results on decoupling with stability for Hamiltonian systems
, Stability and stabilization, Editors: Aeyels, van der Schaft, Lamnabhi-Lagarrigue, Publisher: Springer Verlag -
Journal articleBraslavsky JH, Seron MM, Kokotovic PV, et al., 1999,
Limiting performance of optimal linear filters
, Automatica, Vol: 35, Pages: 189-199 -
Journal articleLaiou C, Astolfi A, 1999,
[no title supplied on import]
, Systems and Control Letters, Vol: 37, Pages: 309-322 -
Conference paperEl-Zobaidi H, Jaimoukha IM, 1999,
Multi-objective model and controller reduction
, IFAC World Congress, Beijing, China, Pages: 3982-3983 -
Book chapterAstolfi A, Menini L, 1999,
Control of Nonlinear Hamiltonian Systems
, Modern Control Theory, Editors: Huba, Menini, Tornambe, Zakova, Publisher: Progetto Leonardo -
Book chapterOrtega R, Astolfi A, Bastin G, et al., 1999,
Output feedback stabilization of mass balance systems
, Output feedback stabilization of nonlinear systems, Editors: Nijmeijer, Fossen, Publisher: Springer Verlag -
Journal articlePytlak R, Vinter RB, 1999,
A Feasible Directions Type Algorithm for Optimal Control Problems with State and Control Constraints: Implementation
, Jota, Vol: 101, Pages: 623-650 -
Conference paperMazenc F, Astolfi A, 1999,
Robust output feedback stabilization of the angular velocity of a rigid body
, 14th IFAC World Congress, Beijing, China -
Journal articleZhou Y, Allwright JC, 1999,
Solution of an optimal control problem using a proximal point algorithm
, IEEE Trans.Automatic Control -
Journal articleHui SYR, Chung H, Ho YKE, et al., 1998,
Modular development of single-stage 3-phase PFC using single-phase step-down converters
, PESC Record - IEEE Annual Power Electronics Specialists Conference, Vol: 1, Pages: 776-782, ISSN: 0275-9306This paper describes the modular development of a family of single-stage AC-DC power converters. The family of converters offers advantageous features such as simple switching control, electrically isolated output, inherent power factor correction, single stage power conversion without using power devices of excessively high voltage and current ratings, the flexibility for expansion of power capability and a simplification of design and production procedure of power converter products. Prototypes up to 1 kW are used to demonstrate the operating principle. © 1998 IEEE.
-
Journal articleChung H, Hui SYR, Wang WH, 1998,
An isolated ZVS/ZCS flyback converter using the leakage inductance of the coupled inductor
, IEEE Transactions on Industrial Electronics, Vol: 45, Pages: 679-682, ISSN: 0278-0046This paper describes a simple and effective way to modify an existing hard-switched flyback converter into a circuit with zero-voltage switching (ZVS) and zero-current switching (ZCS). The key improvement is to turn the unattractive features of the coupled inductor leakage inductance and snubber capacitor into attractive ones. The coupled inductor leakage inductance and snubber are used to form a quasiresonant circuit to facilitate ZVS/ZCS of all power devices. The operating principles of the converter and experimental results are presented. Index Terms-Converter, power electronics, power supplies, resonant power conversion. © 1998 IEEE.
-
Journal articleChung H, Hui SYR, Tse KK, 1998,
Reduction of power converter EMI emission using soft-switching technique
, IEEE Transactions on Electromagnetic Compatibility, Vol: 40, Pages: 282-287, ISSN: 0018-9375Measurements of conducted and radiated electromagnetic interference (EMI) emission from hard-switched and soft-switched buck, boost, and flyback converters of similar power ratings are presented. Results indicate that EMI emission can be substantially reduced by using soft-switching technique in power converters. Thus, soft-switching technique provides a practical and useful solution to reduce EMI emission from switched-mode power circuits. A comparison of EMI emission on the three classes of converters is also included. The flyback converter is found to be the least EMC friendly among the converters tested.
-
Journal articleShrivastava Y, Sathiakumar S, Hui SY, 1998,
Improved spectral performance of random PWM schemes with weighted switching decision
, IEEE Transactions on Power Electronics, Vol: 13, Pages: 1038-1045, ISSN: 0885-8993The authors present a statistical approach to the analysis of random pulsewidth modulation (RPWM) methods which generate PWM signals by comparing a reference modulating function with random numbers or signals. Such an approach is used to analyze and optimize a new weighted RPWM (WRPWM) method and also a standard trapezoidal RPWM method. The WRPWM scheme combines the advantages of the nondeterministic and deterministic PWM methods by adding some deterministic nature into the nondeterministic RPWM method. Both theoretical and experimental results confirm that the optimized WRPWM method has better spectral performance over the standard RPWM schemes and has attractive features such as the potential of third-harmonic boosting, reduced acoustic noise, and minimal low-order harmonics under an over modulation condition for electronic drive applications.
-
Journal articleHui SY, Shrivastava Y, Sathiakumar S, et al., 1998,
A comparison of nondeterministic and deterministic switching methods for DC-DC power converters
, IEEE Transactions on Power Electronics, Vol: 13, Pages: 1046-1055, ISSN: 0885-8993An analysis and experimental results of the random pulsewidth modulation (RPWM) and random pulse-position modulation (RPPM) methods for dc-dc converters are presented. The characteristics and performance of power converters under two randomized modulations are evaluated. The theoretical relationships of discrete harmonics, continuous noise, and output-voltage ripple of the RPWM and RPPM schemes are established and compared with those of a standard deterministic pulsewidth modulation (PWM) scheme in a buck converter. Limitations in the randomly switched dc-dc converters, which have not been addressed before, are highlighted. Randomized schemes generally have inherent problems in achieving low-output-voltage ripple due to the low-frequency continuous noise within the passband of the converter filter. The inherent low-frequency noise-induced voltage ripple problems of nondeterministic switching methods for dc converters are confirmed experimentally. The performance of the RPPM method is found to be closer to the standard PWM method than that of the RPWM method. For dc-dc power conversion, the RPPM method offers much better output-voltage performance than the RPWM method.
-
Journal articleHo YKE, Hui SYR, Lee YS, 1998,
Optimal operation of single-stage three-phase power factor correction circuit using modular PWM DC-to-DC converters
, Electronics Letters, Vol: 34, Pages: 2300-2301, ISSN: 0013-5194A critical conduction parameter A3Φ is derived for the three-phase modular system. This parameter optimises the output filter to achieve the highest power factor of the system. The voltage conversion ratio required to achieve a high power factor to fulfil the harmonic requirements is also derived. Both simulations and experimental results from a 1.5kW prototype using full-bridge converters have confirmed the analysis.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.