具有APF功能的分布式光伏并网及其改进控制

Modified Control of Distributed Photovoltaic Grid-connected System With APF Function

提出一种基于改进型比例谐振(PR)控制器的兼顾有源电力滤波器(APF)功能的分布式光伏并网系统控制策略,在静止坐标系下对基波逆变电流以及需要补偿的各次谐波电流进行无静差跟踪,在将光伏系统的电能注入电网的同时改善电网电能质量。对比分析了PR控制器与改进的PR控制器特性,根据改进PR控制器各参数对性能指标的影响,对改进的PR控制器进行参数设计。仿真和实验结果表明所提的改进PR控制器可以使电流环控制器更好地跟踪指令电流,对电网频率波动具有较好的适应性,验证了所采用的控制策略的可行性和有效性。

A distributed photovoltaic grid-connected system control strategy based on an improved proportional resonance(PR)controller and considering the function of active power filter(APF)is proposed,the fundamental inverter current and the harmonic currents which need to be compensated are tracked without static difference in static coordinate system.The characteristics of PR controller and improved PR controller are compared and analyzed.According to the influence of each parameter of improved PR controller on performance index,the improved PR controller is designed.The simulation and experimental results show that the improved PR controller can make the current loop controller track the command current better,and has better adaptability to the power grid frequency fluctuation,the feasibility and effectiveness of the control strategy are verified.