Remote-Strong-Grid-Point-Based Synchronization Strategy with Fault Ride-Through Capability for Distributed Energy Resources Connected to Weak Grids

Abstract: This paper proposes a novel strategy for the current injection based control for distributed energy resources connected to weak grids through a voltage source converter experiencing faults. The current injection controller is no longer synchronized with the point of common coupling at which the measured voltage signal can be severely affected by faults in the weak grid, but with the strong grid point at which the voltage is rigid. It is shown that the phase difference between the voltage source converter and the strong grid voltages caused by the long power lines does not affect the power control. Furthermore, a time delay compensation method which tolerates communication time delay introduced by the transmission of the synchronization signal from the strong grid point is proposed. The performance of the proposed control strategy is verified with an RTDS Technologies real-time digital simulator using switching converter models.