一种对称半桥解耦电路控制方法及应用分析

Control Method and Application Analysis of a Symmetrical Half-bridge Decoupling Circuit

针对两级式单相光伏并网逆变器交、直流侧功率不平衡问题,提出一种对称半桥拓扑的有源功率解耦电路控制方法,给出了解耦电路的参数计算过程及控制器设计方法,并进行了理论分析。搭建了采用薄膜电容的有源解耦电路、采用电解电容的有源解耦电路和全电解电容的无源解耦电路3种实验电路,从直流母线电容容量、解耦电路成本、体积和寿命等几个方面对其进行了应用对比。最后,结合户外光伏发电应用,给出1 kW采用薄膜电容的光伏并网逆变电路的仿真与实验结果,验证了所提有源功率解耦控制策略的有效性。

For the problem of the power imbalance between the AC side and DC side of the two-stage single-phase photovoltaic grid-connected inverter,a symmetrical half-bridge topology active power decoupling circuit control method is proposed.The parameter calculation process,the design method analysis of the controller and the application of the decoupling circuit are presented.Three kinds of experimental circuits,including active decoupling circuit adopting film capacitors,active decoupling circuit adopting electrolytic capacitors and passive decoupling circuit adopting full electrolytic capacitors,have been built,and they are compared from the aspects of DC bus capacitance,decoupling circuit cost,volume and lifetime.Finally,combined with the application of outdoor photovoltaic power generation,the simulation and experimental results of a 1 kW photovoltaic grid-connected inverter circuit adopting film capacitors are presented,which verify the effectiveness of the proposed active power decoupling control strategy.