Coordinated Control Method for Low Voltage Ride through and Anti-islanding Protection of Distributed PV Generation Based on Interharmonic Impedance

Abstract

As the proportion of distributed PV interconnected into receiving-end grid increases, the structure and operation mode of the traditional grid will undergo crucial variations, and the safe and stable operation of grid will have been impacted. However, there are conflicts and couplings in time between low voltage ride through and anti-islanding protection according to the grid-connected code, so that it is difficult to combine low voltage ride through and anti-islanding protection in terms of time and structure. Therefore, this paper proposes a coordinated control method based on inter harmonic impedance. This method can accurately and quickly distinguish fault state and island state, and then perform corresponding low voltage ride through and anti-islanding protection. Finally, availability of the proposed method was verified according to simulation.