银川东换流站主变压器中性点电抗器配置方案

针对宁夏电网±660 kV 银川东换流站 330 kV 母线单相短路电流超过了开关额定遮断电流的问题,依据宁夏电网 2014 年及 2016 年规划主网架结构,研究了±660 kV 银川东换流站 750 kV 主变压器中性点加装小电抗的限流效果,以有效限制短路电流。通过对电抗器工频过电压、电流和操作过电压、电流的计算分析,选取了中性点避雷器参数,提出了主变压器中性点电抗器的工频和操作过电压水平,对电抗器的动、热稳定电流进行了选择,确定了中性点电抗器的技术参数。结果表明:±660 kV 银川东换流站 750 kV 主变压器加装小电抗可有效限制 330 kV母线单相短路电流。

Configuring scheme on neutral point reactor for main transformer of Yinchuan Eastern converter station

Aiming at the problem of 330 kV bus single phase short-circuit current to surpass switchrated interrupting current in ±660 kV Yinchuan Eastern converter station of Ningxia power grid, bases on main structure of 2014 and 2016 year Ningxia power grid layout,in order to effectivelylimiting short -circuit current,researches the current limiting effect at 750 kV main transformerneutral point which install small reactor in ±660 kV Yinchuan Eastern converter station,bycalculating and analyzing power frequency overvoltage and current of reactor,and operationovervoltage and current of reactor,selects neutral point arrester parameters,puts forward powerfrequency overvoltage level and operation overvoltage level of main transformer neutral pointreactor,selects dynamic and thermal steady current of reactor,confirms technological parameters ofneutral point reactor. The result shows that 750 kV main transformer neutral point to install smallreactor in ±660 kV Yinchuan Eastern converter station can effectively limit single phase short -circuit current of 330 kV bus.