输出并联双有源全桥DC-DC变换器虚拟功率均衡控制方法

摘要

In view of the parallel output dual active bridge(DAB)DC-DC converter in the power electronic transformer(PET), the influence of the front stage cascaded H-bridge (CHB) control strategy on the DAB is analyzed.A virtual power balance control (VPBC) method for DAB with equivalent input series output parallel (ISOP) and equivalent input independent output parallel(IIOP)is proposed,and the mechanism of the control strategy is also analyzed.Finally,the adopted VPBC scheme and input capacitor voltage balance control(VBC)scheme are verified and compared in a three cells experimental platform by using TMS320F28335+FPGA_6SLX45.The experimental results show that the proposed scheme can significantly improve the dynamic response of DAB DC-DC converter for the load and input voltage mutation based on the transmission power balance of each module.Meanwhile,the transient fluctuation of the transmission power in the converter can be effectively suppressed.%针对电力电子变压器(PET)中输出并联双有源全桥(DAB)DC-DC变换器,分析了前级级联多电平整流器(CHB)控制策略对于DAB变换器的影响,提出一种同时适用于等效输入串联输出并联(ISOP)和等效输入独立输出并联(IIOP)DAB变换器的虚拟功率均衡控制方法,并分析了该控制策略的作用机理.搭建了以TMS320F28335+FPGA_6SLX45为控制器的三单元输出并联DAB变换器的实验平台,对所提出的虚拟功率均衡控制方法与输入电容电压平衡控制算法进行了对比验证.实验结果表明,所提方法在实现各个模块传输功率均分的基础上,可以显著提高变换器对于负载突变和输入电压突变时的响应速度.同时,也可有效地抑制变换器传输功率的暂态波动.