A novel detection method and compensation strategy based on PQR transformation for PCC voltage of wind power system

摘要

In order to keep low-voltage ride-through under the grid faults for wind power generation system, this paper proposes a novel three-phase magnitude-phase detection method and voltage sags compensation strategy for the point of common coupling based on PQR transformation. The proposed detection method can decouple the fundamental positive-sequence component and negative-sequence component of three-phase voltages, and detect the magnitudes and phases of them respectively. The novel compensation strategy includes the advantages of pre-sag compensation strategy and in-phase compensation strategy. The simulation results verify that the proposed detection method can overcome the shortcomings of conventional three-phase SPLL, track the magnitude and phase information of the fundamental positive-sequence voltage accurately and improve the speed of dynamic response effectively under the bad harmonic condition. The simulation test for single-phase voltage sag compensation verifies that the proposed strategy can mitigate the phase jump accompanied voltage sags and decrease the amplitude of injecting UDVR voltage.