This article gives an overview of the main passive solutions and active techniques, based on AC switches to limit inrush currents in medium power AC-DC converters （up to 3.7 kW） for electric vehicle charging systems...This article gives an overview of the main passive solutions and active techniques, based on AC switches to limit inrush currents in medium power AC-DC converters （up to 3.7 kW） for electric vehicle charging systems. In particular, a strategy, based on SCR （silicon controlled rectifier） phase, shift control in a mixed rectifier bridge with diodes and thyristors, is proposed. The challenge is to help designers optimize the triggering delay of SCRs to both limit the peak value of inrush current spikes and optimize the charge duration of the DC-link capacitor. A mathematical model （Mathcad engineering tool） has been defined to point out, the interest of a variable triggering delay to control SCRs to meet the expectations described previously. Experimental measurements using an industrial evaluation board of the AC-DC converter demonstrate the robustness of the method.展开更多
This paper presents a very simple scheme for generating quantum controlled phase-shift gate with only one step by using the two vibrational modes of a trapped ion as the two qubits. The scheme couples two vibration de...This paper presents a very simple scheme for generating quantum controlled phase-shift gate with only one step by using the two vibrational modes of a trapped ion as the two qubits. The scheme couples two vibration degrees of freedom coupled with a suitable chosen laser excitation via the ionic states.展开更多
EAST （experimental advanced superconducting tokamak） fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply, which traces the displacement signal of plasma, and excites coils in a v...EAST （experimental advanced superconducting tokamak） fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply, which traces the displacement signal of plasma, and excites coils in a vacuum vessel to produce a magnetic field that realizes plasma stabilization. To meet the requirements of a large current and fast response, the multi- ple structure of the carrier phase-shift three-level inverter is presented, which realizes parallelled multi-inverters, raises the equivalent switching frequency of the inverters and improves the per- formance of output waves. In this work the design scheme is analyzed, and the output harmonic characteristic of parallel inverters is studied. The simulation and experimental results confirm that the scheme and control strategy is valid. The power supply system can supply a large current, and has a perfect performance on harmonic features as well as the ability of a fast response.展开更多
In this paper, on the basis of the phase shifted controlled zero voltage switch (ZVS) full bridge converter with pulse width modulation (PWM), a novel zero voltage and zero current switch (ZVZCS) PWM converter u...In this paper, on the basis of the phase shifted controlled zero voltage switch (ZVS) full bridge converter with pulse width modulation (PWM), a novel zero voltage and zero current switch (ZVZCS) PWM converter using a simple auxiliary circuit was designed. The ZVZCS soft switch is achieved by the resonance among the resisting electromagnetic deflection capacitor, the capacitor of the simple auxiliary network and the leakage inductor of transformer. There are no dissipation devices of the saturation inductor and the auxiliary switch in the converter, meantime the capacitor of the auxiliary circuit is also used to clamp the voltage of the rectifier, and there is no additional clamped circuit. There is no big circulating current in the converter, all the active and passive devices work on the condition of the low current and voltage stress, and the proposed converter has wide load range and small duty loss.展开更多
在设计和研发大功率宽输出电压范围的双有源桥(dual active bridge,DAB)变换器时,传统的电流应力优化策略往往只关注移相比优化,忽略了电感量变化对电流应力的影响,这可能导致在大功率应用中电流应力超出理论预期,从而降低开关管的可靠...在设计和研发大功率宽输出电压范围的双有源桥(dual active bridge,DAB)变换器时,传统的电流应力优化策略往往只关注移相比优化,忽略了电感量变化对电流应力的影响,这可能导致在大功率应用中电流应力超出理论预期,从而降低开关管的可靠性。因此,在大功率应用场景下,为使变换器在全功率范围内获得最小电流应力,首先提出了考虑电感量随电流应力变化的动态关系,并基于此关系选择在恰当电感量下的优化三移相控制方法;其次,通过分析三移相控制并建立相应的数学模型,利用KKT(Karush-Kuhn-Tucker)条件寻求最优移相比组合,以实现电流应力优化;最后,搭建额定功率为100 kW的DAB变换器仿真模型及样机实验平台进行验证。实验结果表明,与传统三移相控制方法相比,所提方法在仿真和实验中都表现出较高的有效性,确保了变换器在整个运行过程中电流应力始终保持在理论预期范围内,保证了变换器在稳定运行时开关管的可靠性。展开更多
文摘This article gives an overview of the main passive solutions and active techniques, based on AC switches to limit inrush currents in medium power AC-DC converters （up to 3.7 kW） for electric vehicle charging systems. In particular, a strategy, based on SCR （silicon controlled rectifier） phase, shift control in a mixed rectifier bridge with diodes and thyristors, is proposed. The challenge is to help designers optimize the triggering delay of SCRs to both limit the peak value of inrush current spikes and optimize the charge duration of the DC-link capacitor. A mathematical model （Mathcad engineering tool） has been defined to point out, the interest of a variable triggering delay to control SCRs to meet the expectations described previously. Experimental measurements using an industrial evaluation board of the AC-DC converter demonstrate the robustness of the method.
基金supported by the National Natural Science Foundation of China (Grant No 10574001)the Program of the Education Department of Anhui Province (2004kj029) of China+1 种基金the Talent Foundation of Anhui University of Chinathe Youth Program of Fuyang Teachers College of China (Grant Nos 2005LQ03 and 2005LQ04)
文摘This paper presents a very simple scheme for generating quantum controlled phase-shift gate with only one step by using the two vibrational modes of a trapped ion as the two qubits. The scheme couples two vibration degrees of freedom coupled with a suitable chosen laser excitation via the ionic states.
基金supported by Key Project of National Ninth Five-Year Research Program of China[(1998)1303]
文摘EAST （experimental advanced superconducting tokamak） fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply, which traces the displacement signal of plasma, and excites coils in a vacuum vessel to produce a magnetic field that realizes plasma stabilization. To meet the requirements of a large current and fast response, the multi- ple structure of the carrier phase-shift three-level inverter is presented, which realizes parallelled multi-inverters, raises the equivalent switching frequency of the inverters and improves the per- formance of output waves. In this work the design scheme is analyzed, and the output harmonic characteristic of parallel inverters is studied. The simulation and experimental results confirm that the scheme and control strategy is valid. The power supply system can supply a large current, and has a perfect performance on harmonic features as well as the ability of a fast response.
文摘In this paper, on the basis of the phase shifted controlled zero voltage switch (ZVS) full bridge converter with pulse width modulation (PWM), a novel zero voltage and zero current switch (ZVZCS) PWM converter using a simple auxiliary circuit was designed. The ZVZCS soft switch is achieved by the resonance among the resisting electromagnetic deflection capacitor, the capacitor of the simple auxiliary network and the leakage inductor of transformer. There are no dissipation devices of the saturation inductor and the auxiliary switch in the converter, meantime the capacitor of the auxiliary circuit is also used to clamp the voltage of the rectifier, and there is no additional clamped circuit. There is no big circulating current in the converter, all the active and passive devices work on the condition of the low current and voltage stress, and the proposed converter has wide load range and small duty loss.
文摘在设计和研发大功率宽输出电压范围的双有源桥(dual active bridge,DAB)变换器时,传统的电流应力优化策略往往只关注移相比优化,忽略了电感量变化对电流应力的影响,这可能导致在大功率应用中电流应力超出理论预期,从而降低开关管的可靠性。因此,在大功率应用场景下,为使变换器在全功率范围内获得最小电流应力,首先提出了考虑电感量随电流应力变化的动态关系,并基于此关系选择在恰当电感量下的优化三移相控制方法;其次,通过分析三移相控制并建立相应的数学模型,利用KKT(Karush-Kuhn-Tucker)条件寻求最优移相比组合,以实现电流应力优化;最后,搭建额定功率为100 kW的DAB变换器仿真模型及样机实验平台进行验证。实验结果表明,与传统三移相控制方法相比,所提方法在仿真和实验中都表现出较高的有效性,确保了变换器在整个运行过程中电流应力始终保持在理论预期范围内,保证了变换器在稳定运行时开关管的可靠性。
