Islanding Detection Method for Inverter Cluster Based on Interharmonic Impedance Measurement

摘要

As the number of grid-connected inverters in distributed generation systems increases, the detection signal of the active method will interfere with each other. According to the reason, it is necessary to study the islanding detection technology applicable to the inverter clusters with different control strategies. In this paper, the islanding detection method of inverter clusters based on interharmonic impedance measurement is studied. The detection principle of the method is that the impedance of the system increases when islanding operation state is enabled. This method connects the interharmonic disturbance device at the point of common coupling, and collects the interharmonic voltage and current at the output terminals of the disturbance device by FFT. Then, the interharmonic impedance change between systems and judge is calculated whether the system is in the islanding operation state. Finally, the effectiveness of the method is confirmed by MATLAB/Simulink platform.