With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reductio...With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology＇, the existing chopper circuit is used for the electric vehicles, etc.. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar.展开更多
A on,dimensional ring subject to Rashba spin-orbit coupling is investigated. When it is attached to a lead with spin-dependent chemical potential, there will be charge current in the ring. The charge current response ...A on,dimensional ring subject to Rashba spin-orbit coupling is investigated. When it is attached to a lead with spin-dependent chemical potential, there will be charge current in the ring. The charge current response is resonantly maximized when the Fermi energy of the lead is equal to any energy level of the 1D ring. And if two probes are attached to the ring, the electric voltage between them creates sawtooth-like wave, which indicates the direction of the charge current. A ferromagnetic lead can also induce persistent charge current, which can be detected by magnetization intensity measurement.展开更多
The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss a...The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss and significantly increase the converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to n-mode versus 1/n mode. This is accomplished by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter has been designed with the coupled inductors. The simulation and experimental results have been used to demonstrate the performance of the two-phase with and without coupled inductor interleaved QR ZCS SC converters for bidirectional power flow control application, and an extending structure for N-phase is mentioned.展开更多
We investigate two different kinds of resonant current regulators for a doubly fed induction generator(DFIG) under distorted grid voltage conditions: proportional integral resonant(PIR) regulator with traditional reso...We investigate two different kinds of resonant current regulators for a doubly fed induction generator(DFIG) under distorted grid voltage conditions: proportional integral resonant(PIR) regulator with traditional resonant part and vector proportional integral(VPI) regulator with VPI resonant part. Based on the mathematical model of DFIG under distorted grid voltage, the transfer function and frequency response characteristics of the two current regulators are analyzed and compared. The superiority of the VPI current regulator over the PIR regulator is pointed out, and the influence of discretization methods on the performance of the resonant current regulator is studied. All the results are validated by MATLAB simulation and experiments.展开更多
Resonant converter(RC)was brought under research in the 80’s widely,which can attain very small switching loss,therefore,facilitating resonant topologies to function at the high switching frequency.It is well address...Resonant converter(RC)was brought under research in the 80’s widely,which can attain very small switching loss,therefore,facilitating resonant topologies to function at the high switching frequency.It is well addressed in the review that the optimal parameterization of the resonant converter is a crucial task.While the literature has come out with different methodologies,they are highly conceptual and so the uncertainty due to high theoretical impact persists.This paper intends to develop a Parameter Optimization(PO)algorithm for designing and developing of LLC-RC.The proposed algorithm overwhelms the limitation by introducing a nonconceptual model based on the simulated outcome.Specifically,the resonant current under start-up conditions is acquired from the literary outcome,and the intelligent model is constructed.Based on the proposed model,a renowned search algorithm called as Whale Optimization Algorithm(WOA)is exploited to optimize the time constant of the resonant converter,which is a critical design parameter.The objective model is derived as a function of start-up time and so the start-up time can be minimized.Moreover,the response speed of the output voltage is also increased.The proposed Whale Optimization Algorithm based Parameter Optimization(WOAPO)is compared with the conventional techniques such as IAPO,Ant Bee Colony-PO(ABC-PO),Particle Swarm Optimization-PO(PSOPO),FireFly PO(FFPO)and Grey Wolf Optimization(GWOPO).The obtained result verifies the performance of the proposed method in modeling LLC-RC system.展开更多
文摘With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology＇, the existing chopper circuit is used for the electric vehicles, etc.. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar.
文摘A on,dimensional ring subject to Rashba spin-orbit coupling is investigated. When it is attached to a lead with spin-dependent chemical potential, there will be charge current in the ring. The charge current response is resonantly maximized when the Fermi energy of the lead is equal to any energy level of the 1D ring. And if two probes are attached to the ring, the electric voltage between them creates sawtooth-like wave, which indicates the direction of the charge current. A ferromagnetic lead can also induce persistent charge current, which can be detected by magnetization intensity measurement.
文摘The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss and significantly increase the converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to n-mode versus 1/n mode. This is accomplished by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter has been designed with the coupled inductors. The simulation and experimental results have been used to demonstrate the performance of the two-phase with and without coupled inductor interleaved QR ZCS SC converters for bidirectional power flow control application, and an extending structure for N-phase is mentioned.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2011AA050204)the National Natural Science Foundation of China(No.51277159)
文摘We investigate two different kinds of resonant current regulators for a doubly fed induction generator(DFIG) under distorted grid voltage conditions: proportional integral resonant(PIR) regulator with traditional resonant part and vector proportional integral(VPI) regulator with VPI resonant part. Based on the mathematical model of DFIG under distorted grid voltage, the transfer function and frequency response characteristics of the two current regulators are analyzed and compared. The superiority of the VPI current regulator over the PIR regulator is pointed out, and the influence of discretization methods on the performance of the resonant current regulator is studied. All the results are validated by MATLAB simulation and experiments.
文摘Resonant converter(RC)was brought under research in the 80’s widely,which can attain very small switching loss,therefore,facilitating resonant topologies to function at the high switching frequency.It is well addressed in the review that the optimal parameterization of the resonant converter is a crucial task.While the literature has come out with different methodologies,they are highly conceptual and so the uncertainty due to high theoretical impact persists.This paper intends to develop a Parameter Optimization(PO)algorithm for designing and developing of LLC-RC.The proposed algorithm overwhelms the limitation by introducing a nonconceptual model based on the simulated outcome.Specifically,the resonant current under start-up conditions is acquired from the literary outcome,and the intelligent model is constructed.Based on the proposed model,a renowned search algorithm called as Whale Optimization Algorithm(WOA)is exploited to optimize the time constant of the resonant converter,which is a critical design parameter.The objective model is derived as a function of start-up time and so the start-up time can be minimized.Moreover,the response speed of the output voltage is also increased.The proposed Whale Optimization Algorithm based Parameter Optimization(WOAPO)is compared with the conventional techniques such as IAPO,Ant Bee Colony-PO(ABC-PO),Particle Swarm Optimization-PO(PSOPO),FireFly PO(FFPO)and Grey Wolf Optimization(GWOPO).The obtained result verifies the performance of the proposed method in modeling LLC-RC system.
