This article presents an improved reverse power protection for spot network with high penetration of photovoltaic (PV) interfaced with inverter. First, the current variation within a short time window is discussed respectively when fault occurs and PV operates with fluctuation. It can be used to determine the cause of reverse power. Second, the positive sequence fault component power is analysed when different types of fault occur at various locations. The fault section can be located mainly by comparing the power direction of positive sequence fault components among feeders, as well as comparing the output current of PV inverter with the current through its connecting switchgear. Finally, the improved reverse power protection for spot network with PV is presented, including the operating value and protection logic. This method can enhance the penetration of PV in spot network. The simulation model based on practical projects is constructed. The protection performance including load and PV fluctuation, and all kinds of fault is simulated with comparison to the present protection method. The simulation results prove the validity of the improved protection.
- Positive sequence fault component
- Reverse power protection
- Spot network