基于有源电力滤波与谐波补偿的孤岛检测方法

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.