一种新型零电压切换双向DC/DC变换器的设计与仿真

Design and simulation of a novel bidirectional DC/DC converter with zero voltage transition function

由于电动汽车电源变换器在行驶过程中,电机的调速范围很宽,加减速频繁,因此对电源变换器的动态响应速度,续航能力提出了更高的要求。但汽车电源存在低电压大电流、di/dt和du/dt较大、转换效率低和电磁干扰严重等问题。为此,设计一种新型的具有升压-降压功能的零电压转换双向DC-DC变换器。在传统的升降压变换器的基础上,通过增加两个辅助开关器件和一个LC谐振电路,构成一个H-软开关控制转换电路,产生的有源钳位电压加载到主开关两端,实现电路零电压转换。在Matlab环境下,对所提出的电路进行仿真,结果表明,所设计的电路能降低开关器件的导通损耗,提高电源的效率,并在6 kW双向升降压变换器样机上进行实验。

Since the motor has wide speed regulation range and frequent acceleration and deceleration during the driving process of electric vehicle,it is required that the power converter should have faster dynamic response and higher cruising ability.However,the automotive power supply has the problems such as low voltage with large current,large di/dt,large du/dt,low conversion efficiency and serious electromagnetic interference.Therefore,a novel bidirectional DC/DC converter with the zero voltage transition(ZVT)and buck-boost voltage functions is designed.Two auxiliary switching devices and an LC resonance circuit are added on the basis of the conventional buck-boost voltage converter to constitute an H-soft switching control conversion circuit.The generated active-clamp voltage is loaded to the two ends of the master switch,so as to realize ZVT of the circuit. The proposed circuit was simulated in the Matlab environment.The results show that the designed circuit can reduce the conduction loss of switching devices and improve the efficiency of power supply.It was tested on the prototype of the 6 kW bidirectional buck-boost voltage converter.