多机光伏并网逆变器并联运行的孤岛检测方法研究

Research on detection method of parallel operation of multi machine photovoltaic grid-connected inverter

针对传统带正反馈的主动移频(Active Frequency Drift Positive Feedback,AFDPF)方法的不足,提出了改进型正反馈主动频率偏移孤岛检测方法,分析了改进型AFDPF孤岛检测方法的基本原理和孤岛检测盲区(Non-Detection Zone,NDZ)。通过Matlab/Simulink仿真软件建立了两台光伏并网逆变器并联的仿真模型,在单台逆变器和两台逆变器运行情况下分别对传统AFDPF和改进型AFDPF孤岛检测方法进行了仿真研究。仿真结果表明,改进型AFDPF孤岛检测方法在单台和两台逆变器运行情况下均能够准确检测出孤岛,且满足IEEE std.929-2000标准。

Island detection technology is one of the key technologies of photovoltaic grid connected power generation system. Aiming at the shortage of the traditional AFDPF method, an improved active frequency drift positive feedback（AFDPF） detection method is proposed, and the basic principle and the non-detection zone（NDZ） of the improved AFDPF method are analyzed. The simulation model of two PV grid connected inverter is established by the Matlab/Simulink simulation software, and the simulation research of the traditional AFDPF and the improved AFDPF island detection method is carried out in the single inverter and the two inverter operation. The simulation results show that the improved AFDPF island detection method can accurately detect the isolated island under single stage and two inverters operation conditions, and meet the standard of IEEE std.929-2000.