220kV开关站站用变电流互感器参数选择

Parameter Selection of Current Transformer for 220kV Switching Substation's Station Transformer

电流互感器的选择要根据系统短路电流、互感器实际二次负荷、保护整定值和灵敏度要求进行综合考虑。按最大短路电流不超过电流互感器准确限值电流的原则选择电流互感器额定一次电流,可能导致保护整定困难;按设备额定容量选择电流互感器额定一次电流,则可能导致互感器过饱和引起保护拒动。为解决上述问题,提出了按保护整定计算确定站用变压器电流互感器参数的方法和过程。

The set of current transformer should be considered comprehensively according to the system short circuit current,actual secondary load of mutual inductor,setting value of protection,requirement of sensitivity.To set the rated primary current of current transformer according to the principle of maximum short-circuit current should be no more than the accurate limit current value of current transformer,it would lead to difficulties for the value setting of protection.To set the rated primary current of current transformer according to rated capacity of equipment would lead to protection failure caused by oversaturation of current transformer.To solve the problems above,a method that set the parameters of current transformer based on setting value of protection is proposed.