Configuration, cooperation and existing problems of wind farm relay protection

The objective of conventional wind power relay protections is to maintain the system´s stable operation. However, the protections´ selectivity is not high enough to enable the wind turbine to ride through low-voltage faults. Thus, with an increasing wind power capacity, it is required that the wind turbines possess more strict low-voltage ride-through(LVRT) ability, otherwise the stability of power grid may be endangered. With the cooperation of relay protections, LVRT ability ensures the wind turbine to remain grid-connected under different fault conditions. This paper presents the configuration of conventional wind power relay protections and their cooperation with the power grid. In addition, the existing problems of grid-connected wind power systems are proposed. We also analyze the wind turbine LVRT characteristics and its cooperation operating time with the relay protection. In this paper, the improvement of relay protection that possesses LVRT ability and other key problems are further discussed.