Research on Distributed Photovoltaic Low Voltage Ride Through Control Strategy Considering Distribution Network Protection

The high proportion of distributed photovoltaic (PV) accessed to the distribution network changes the fault characteristics of the distribution network, and the traditional distribution network protection may have the possibility of incorrect action. At present, the output strategy during low voltage ride-through (LVRT) mainly considers distribution grid voltage support and frequency stability, and rarely considers the impact on distribution grid relay protection. First, this paper analyzes the impact of distributed PV access location, access capacity and LVRT control strategy on the distribution grid short-circuit current. Then, a distributed PV LVRT control strategy considering distribution grid protection is proposed, which provides distribution grid reactive and active support with less impact on distribution grid protection, enabling the traditional distribution grid protection to be applied to active distribution grid. Taking a regional distribution network as an example, the effectiveness of the control strategy is verified, which provides a theoretical basis for the subsequent development of active distribution network fault disposal and recovery.