一种基于模糊控制的改进主动式孤岛检测法

摘要

孤岛检测是分布式发电系统中必须解决的重点问题之一,确保了电力系统的安全和稳定.但以往检测方法多存在检测效率低和检测时间长等情况,针对这些问题,提出一种改进的主动移相式孤岛检测法,并对改进后的方法展开原理分析.根据孤岛发生时,公共结合点电压频率的变化情况对频率变化量和频率变化率进行模糊控制,对改进后算法中的参数进行自动整定.基于Matlab/Simulink的仿真结果表明改进后的方案提高了检测效率,缩短了检测时间,对电能质量影响小,具有一定实用参考价值.%Islanding detection is one of the important problems of distributed photovoltaic power generation,which guarantees the security and stability of the entirety power system.Most of the previous detection methods always have an inefficient detection,and cost a long time.To solve these problems,an improved active phase-shift islanding detection method was proposed,and the principle and analysis of improved method were unfolded.The parameter of improved method was set automatically due to the change condition of frequency and voltage at the point of common coupling and it took a fuzzy control to the rate of frequency change and frequency variation when the islanding occured.Simulation results based on Matlab/Simulink indicate that the improved method has increased the detection efficacy,shorten the time and has a low influence to power quality,which has practical reference value for application.