Cause analysis on large-scale wind turbine tripping and its countermeasures

Several large-scale wind turbine tripping accidents occurred in Jiuquan wind power base in 2011. According to the on-site survey and the oscillogram analysis,the cause of these accidents is the short-circuit fault of electrical equipment and cables in wind farm,which leads to the voltage drops in the farm and system,therefore a large number of wind turbines trip because they do not have the low voltage ride through(LVRT) capability. After the fault is cleared,a large number of wind turbines trip again when the system voltage rises to setting point of overvoltage of wind turbine,because the reactive power compensation device in wind farm step-up substation can not timely regulate the voltage automatically. Accordingly,wind turbine retrofitting and collector system and its protection configuration improvement are put forward from a practical point of view,and combining with the characteristics of large-scale wind power base,the subjects to prevent wind power reasonably from large-scale tripping are also put forward for further research.