风电场集电线路电流速断保护整定研究

The instantaneous over-current protection of wind farm collector line research

风电场的接线方式和运行方式与常规火电厂不同,机组往往通过箱变升压后经集电线路相连,再升压后并入电网,因此集电线路保护对风电场的稳定运行十分重要。而风力发电机组提供的短路电流与常规同步发电机组的特征并不相同,所以需要对风电场内部集电线路电流保护的整定计算进行深入研究。通过分析双馈风机机端电压发生对称性深度跌落时,转子撬棒保护动作后的定子短路电流表达式,并结合线路电流保护的需要重点分析了定子短路电流中的稳态基频部分,并进行了仿真验证,在此基础上给出了风电场集电线路的电流速断保护的整定方法,并给出了整定计算实例。

Wiring and operation mode of wind farms is different from conventional thermal power plants, the export voltage of wind turbine is step-up by the box transformer, then is connected by collector lines to the grid, so the protection of collector lines is very important for the stable operation of the wind farm. The characteristics of the wind turbine short-circuit current is not the same as the synchronous generator, so the deep study of wind farm collector lines current protection is needed. By analyzing the wind turbine stator short-circuit current expression, and combining with the fundamental frequency part of the stator short-circuit current which current protect needs, a method for the instantaneous over-current protection of wind farm collector line is proposed, and a example shows the method right.