直流微网系统用交错并联双向直流变换器控制方法

直流微电网系统的能量需要双向传输,为了解决双向交错并联变换器相间不均流的问题,本文研究了一种应用于直流微电网系统的交错并联双向Buck/Boost直流变换器的含有同步整流调制的带占空比分配的控制方法。本文描述了变换器的运行原理,然后对变换器的调制方式与控制方法进行了详细分析。该方法在传统的PI控制方法上引入了占空比再分配方法,根据每相电感电流的大小调节每相占空比,既能实现稳定的输出电压电流,也能自动实现两相均流,同时该方法可拓展到多相变换器,并且同步整流控制也使得变换效率更高。最后,搭建了低压侧为40~120 V,高压侧为200 V,输出功率为5 kW的仿真模型。仿真模型验证了理论分析的正确性。

Control Method of Interleaved Bidirectional DC-DC Converter for DC Microgrid System

To satisfy the requirement of bidirectional energy transmission in a DC microgrid system,a control method with duty cycle assignment and synchronous rectification modulation is studied in this paper,which can be applied to an interleaved bidirectional Buck/Boost DC-DC converter in the DC micro grid system to solve the problem of unbal?anced current-sharing among phases.The operating principle of the converter,as well as its modulation mode and con?trol method,is analyzed in detail.Using this method,the duty cycle assignment is introduced on the basis of the tradi?tional PI control method,such that the duty cycle can be adjusted according to the value of inductor current per phase.As a result,the stable output voltage and current can be obtained,and the two-phase current-sharing can be achieved automatically.Meanwhile,this method can be extended to multi-phase converters,and the conversion efficiency can be improved owing to the synchronous rectification control.At last,a 5 kW simulation model with 40-120 V on the lowvoltage side and 200 V on the high-voltage side is built,and simulation results validate the theoretical analysis.