电力电子变压器隔离级并联双有源变换器的控制与建模研究

Research on control and modeling method of parallel dual active bridge converter in power electronic transformer

电力电子变压器中隔离级采用多双有源桥变换器模块并联结构时,隔离级需要同时实现低压直流母线电压控制以及模块电流均衡控制,对此,文章提出了采用低压直流母线电压外环和并联模块电流内环的双环控制结构。给出多双有源桥并联系统小信号建模方法,建立多双有源桥变换器并联的小信号模型,分析了电压调节器和电流调节器参数变化对系统特性的影响,为参数选取提供了理论依据。最后通过仿真分析验证了所提控制方法的有效性和建模方法的准确性。

According to the requirement of low-voltage DC bus voltage control and module current sharing control under the multi dual active bridge converter parallel operation situation of power electronic transformer,a double loop control structure is proposed,in which the outer loop is used to implement the DC bus voltage control and the inner loop used to achieve module current sharing control.A multi dual active bridge parallel system modeling method based on small signal analysis is proposed,the small signal model of multi dual active bridge converter parallel is established,the effect of current parameters on the system performance is analyzed,and the control parameters are selected according to the analysis results.Simulation results are provided to validate the proposed control method and modeling method.