基于正反馈主动移频式孤岛检测算法的模糊优化

Fuzzy optimization of islanding detection algorithm based on active frequency drift with positive feedback

孤岛检测是并网光伏发电系统必备的功能,基于正反馈的主动频率偏移法是目前应用最为广泛的一种孤岛检测算法。针对该算法在反馈参数选择时孤岛检测盲区和输出电能质量难以兼顾的问题,分析了算法参数与孤岛检测盲区和输出电能质量的关系,给出了算法参数的选取范围,采用模糊控制,根据电网断开后公共点电压频率的变化情况对反馈参数进行了自适应在线调整,建立了基于Simulink/SimPowerSystems的孤岛检测仿真模型。仿真结果表明,该方法不仅能够实现并网光伏发电系统的无盲区检测,而且其输出电流畸变率比常规算法降低了1.49%。

Anti-islanding protection is mandatory feature for grid-connected inverters. Active frequency drift （AFD） with positive feedback islanding detection method is the most widely used at present. It is difficult to give consideration to non-detection zone and output power quality when chose the algorithm parameter. In order to solve the problem, firstly, the relationship between the algorithm parameter and the above two aspects was analyzed, and then the rang of algorithm parameter was given. Finally, the feedback parameter was adaptively online adjusted based on fuzzy control according to the change of voltage frequency at point of common coupling when grid model for islanding detection based on Simulink/SimPowerSystems was established. Simulation results demonstrate this method not only can have no non-detection zone, but also reduces the output current distortion by 1.49% than the conventional algorithm.