基于有源电力滤波与谐波补偿的孤岛检测方法

ISLANDING DETECTION METHOD BASED ON ACTIVE POWER FILTER AND HARMONIC COMPENSATION

电力系统中非线性负载的存在会严重影响电能质量,传统的基于阻抗测量的孤岛检测法会加剧电能质量的恶化。针对此问题,提出利用有源电力滤波器(APF)补偿非线性负载产生的谐波,根据电网阻抗变化对注入补偿电流的影响,通过检测APF端口处等效阻抗的变化判断是否发生孤岛效应。建立带非线性负载分布式发电系统的等效模型,给出APF的谐波检测法及其控制策略。由于无需额外注入扰动量,因此在提高系统电能质量的同时可完成孤岛检测。仿真和实验验证了该方法的可行性。

The existence of nonlinear loads in the power system will seriously affect the power quality.Traditional islanding detection method based on impedance measurement will aggravate the deterioration of power quality.Aiming at this problem,this paper puts forward a new method that by using active power filter(APF)to compensate harmonic current caused by nonlinear loads and considering compensation current of APF as a disturbance.In this way,islanding mode is judged by detecting the change of the equivalent impedance of the APF port.The equivalent model of distributed generation system with nonlinear loads is established.The harmonic current detection method and the corresponding control strategy of the implemented APF are given.Considering the compensation current as disturbance,the harmonic current compensation and islanding detection can be conducted simultaneously.The simulation and experimental results verify the feasibility of proposed method.