单相光伏并网逆变器无功补偿控制策略

Reactive Power Compensation Control Strategy of Single-phase Photovoltaic Grid-connected Inverter

针对传统单相光伏逆变器功能单一的特点,对具有无功补偿功能的光伏并网逆变器控制策略进行了研究,拓展了光伏逆变器的功能。提出了一种正弦信号积分法结合瞬时无功功率理论的方法,来检测有功电流和无功电流,克服了传统单相无功检测法的时延问题。系统采用传统的双闭环控制,电压外环采用PI控制,稳定母线电压,电流内环采用准比例谐振控制器,实现了电流的无稳态误差跟踪。仿真和实验结果证明了该方法的有效性和正确性。

To break the single mode of traditional single phase photovoltaic, a single phase PV grid-conneted inverter system with reactive power compensation function was proposed, which expending the PV inverter functions. A sinusoidal signal integrator method was proposed. Active current and reactive current were detected by using the method combine with the instantaneous reactive power theory, which overcomes the latency problem of the conventional single-phase reactive detection method. The system adopted the traditional double-loop control. The bus voltage was kept stable by using the PI control on the voltage loop. Zero steady-state error was realized by applying a quasi proportional resonant controller on the current loop. Simulation and experimental results show the effectiveness and accuracy of the method.