The Research Of HVDC Impact On The Relay Protection Of Ac Network And The Solution Measure

When the AC network is in fault, HVDC is possibly to enter abnormal operation state and produce fault voltage and current in AC-DC interconnected power system which are different from pure AC system. The interaction of fault voltage and current has different effects on different relays. This paper analyzes the fault characteristics of fault voltage and current generated by HVDC, and analyzes the impact on the jump-value of current direction relay, distance protection Pilot and Longitudinal Differential Protection. The study found that HVDC has great effect on the jump-value of current direction relay and distance protection Pilot but has little effect on the Longitudinal Differential Protection.