结合电流应力优化的ISOP-DAB变换器电压均衡控制

VOLTAGE BALANCE CONTROL OF ISOP-DAB CONVERTERS WITH CURRENT STRESS OPTIMIZATION

当输入串联输出并联(ISOP)型双有源桥(DAB)DC-DC变换器系统各模块参数不同时,系统存在传输功率不均衡导致的过电压过电流现象,严重时可能损坏器件,此外变换器运行时还需考虑其电流应力与动态性能。针对这些问题,基于双重移相提出一种结合电流应力优化的电压均衡控制方案。分析双重移相下变换器的电流应力与传输功率模型,并通过KKT(Karush-Kuhn-Tucker)条件法求取电流应力最优的移相比公式。在电流应力优化的基础上提出一种电压均衡控制方法,通过传输功率模型推导桥间移相比表达式,引入均压分量和动态传输功率,实现输入电压均衡、输出电压稳定以及提高动态性能。最后,搭建双模块ISOP-DAB实验平台进行对比实验,验证所提控制方法的有效性。

When the parameters of each module in the input series output parallel(ISOP)dual active bridge DC-DC(DAB)converter system are different,the system has over-voltage and over-current caused by unbalanced transmission power,which may damage the device in serious cases.In addition,current stress and the dynamic performance of converters should also be considered during operation.To address these issues,this paper proposes a voltage balance control scheme combined with current stress optimization based on dual phase shift.The current stress and transmission power model of the converter under dual phase shift is analyzed.And then the phase shift ratio for current stress optimization is obtained by the KKT condition method.On the basis of current stress optimization,a voltage balance control method is proposed.The outer phase shift ratio expression is deduced through the transmission power model,and the voltage balance component and dynamic transmission power are introduced to achieve input voltage balance and output voltage stability and improve dynamic performance.Finally,a dual-module ISOP-DAB experimental platform is built,and comparative experiments are carried out to verify The effectiveness of the control method in this paper is verified by the comparative experiments.