A study on influence of wind power on positive sequence voltage polarized impedance relay

Wind power has made rapid progress in the last few years. However, large-scale wind power integration exerts negative influence to power system. One of the problems is that with the current supplied by wind farm feeder, relay protection may be of incorrect trip or miss trip. To study the influence of wind power on positive sequence voltage polarized impedance relay, this paper gives a mathematical analysis of the relay´s operation equation. And a simulation of the integration of wind turbine driven doubly fed induction generator is accomplished by PSCAD software to verify the mathematical analysis. The results show that with integration of wind power, the protecting range of quick-break distance protection is extended and the operating time of distance protection with time limit may be delayed. Those conclusions provide theoretical basis for selection and setting of protection.