A Low Voltage Ride-Through Control Strategy of Distributed Generation for Improving Reactive Power Support Capability

With the increasing penetration of distributed generation (DG) in distribution networks, its impact on the stability of the grid has become more pronounced. To improve the low voltage ride-through (LVRT) capability of DG, a LVRT control strategy for improving the reactive power support capability of DG is proposed. This control strategy designs two output current control equations as LVRT control equations based on the LVRT requirements of DG for different positive sequence voltages at the point of common coupling (PCC) of DG. By comparing the positive-sequence voltage at the PCC of DG with the boundary voltage of DG, the corresponding LVRT control equation is selected. The simulation results from PSCAD/EMTDC indicate that, under slight fault conditions in the distribution network, the proposed control strategy can effectively increase the reactive current output of DG, elevate the voltage at the PCC of DG, and improve the LVRT capability of DG. Simultaneously, it enhances the fault current in the system, which is beneficial to fault detection.