双有源桥DC-DC变换器虚拟直接功率控制策略

动态响应特性是双有源桥(Dual Active Bridge,DAB)DC-DC变换器的一个关键指标。为了提高DAB DC-DC变换器在系统发生扰动时的动态响应速度,在单移相控制的基础上,结合直接功率前馈控制(Direct Power Feed-Forward Control,DPFFC)策略,提出了一种虚拟直接功率控制(Virtual Direct Power Control,VDPC)策略,并建立了VDPC策略下系统发生扰动时的小信号模型,该控制方法无电感、无变压器变比等电路参数参与控制,提高了控制方法的兼容性。最后,在Matlab/Simulink仿真平台上,对虚拟直接功率控制和直接功率前馈控制进行了对比仿真,仿真结果表明:在DAB DC-DC变换器输入电压和负载发生扰动时,虚拟直接功率控制方法具有更快的动态响应性能,且能保证输出电压基本不变。

Virtual Direct Power Control Scheme of Dual Active Bridge DC-DC Converter

The dynamic response characteristic is a key index for the dual active bridge DC-DC converter.In order to enhance the dynamic response speed for DAB (dual active bridge) DC-DC converter as its system disturbance,combing the control strategy of the DPFFC (direct power feed-forward control),this paper proposes a VDPC (virtual direct power control) scheme with single-phase-shift control for DAB DC-DC converter,and on the basis of VDPC strategy,a small signal model is built as its system disturbance,which is not dependent on circuit parameters such as inductance,ratio of transformer,and can improve compatibility.Finally,the adopted virtual direct power control and direct power feed-forward control are verified and compared in Matlab/Simulink,and the simulation results show that the virtual direct power control scheme can significantly enhance the dynamic response of the DAB DC-DC converter,and keep the output voltage constant while the output voltage and load step is up or down.