三有源桥DC-DC变换器广义状态空间平均模型及控制策略研究

Research on Generalized State Space Average Model and Control Strategy for Triple Active Bridge DC-DC Converter

基于移相加占空比控制策略的三有源桥TAB(triple active bridge)DC-DC变换器具有效率高和软开关范围可扩展等优点,但其小信号建模过程复杂、闭环控制环路参数整定困难。针对该问题,提出1种TAB工作在移相加占空比控制下的全阶连续广义状态平均建模和PI控制器设计方法。首先,分析TAB的运行原理和Y型等效结构;然后,结合移相加占空比控制的特点和交流方波源等效方法,推导出TAB的广义状态空间平均模型;接着,在推得模型的基础上求得输入到输出的传递函数,设计出PI控制器参数。最后,结合数字仿真及样机实验验证了所提方法的正确性及有效性。

The triple active bridge(TAB)DC-DC converter based on the phase-shifting plus duty cycle control strategy has advantages such as a high efficiency and an expandable soft switching range.However,its small signal modeling process is complex,and the parameter setting of closed-loop control loop is difficult.To solve these problems,a full-orer continuous generalized state space average modeling and PI controller design method for TAB converter under phaseshifting plus duty cycle control is proposed.First,the operation principle and Y-type equivalent structure of the TAB converter are analyzed.Second,combined with the characteristics of phase-shifting plus duty cycle control and the equivalent method of AC square wave source,the generalized state space average model of the TAB converter is derived.Third,based on the derived model,the transfer function from input to output is obtained,and the parameters of PI controller are designed.Finally,the correctness and effectiveness of the proposed method were verified by digital simulations and prototype tests.