无大容量电解电容式单相光伏并网系统

提出一种基于功率向量补偿的控制方法。结合直流母线电压外环、电网电流和补偿电感电流内环的控制结构,在普通单相光伏并网系统拓扑基础上增加一对开关管与一个补偿电感,使补偿电感上的二倍频功率向量与原有的直流母线上二倍频功率向量大小相等、方向相反,减小直流母线二倍频功率波动,直流侧可以用小容量的薄膜电容代替大容量电解电容。仿真结果表明使用该方法能显著减小直流侧电容值。

A Single Phase Photovoltaic Grid-connected System Without High-capacity Electrolytic-capacitor

A control method based on power vector compensation strage was proposed.Combining control structures of DC bus voltage outer loop,grid current and compensation inductive current inner loop,a pair of switching valve and a compensation inductance were added to topology of traditional single-phase photovoltaic grid-connected systems.Twice-grid frequency power vectors of the compensation inductance and the original DC bus are equal in size,and opposite in direction,which reduces twice-grid frequency power fluctuations of DC bus.Large-capacity film capacitors can be replaced with small capacity electrolytic capacitors on DC side.Simulation results show that the capacitance value of DC side can be significantly reduced with the proposed method.