10/0.4kV变压器低压侧短路电流的近似计算及应用

Approximate calculation of short-circuit current on the low-voltage side of 10/0.4kV transformer and its application

通过分析有名值法的计算过程,推导出一种近似计算10/0.4 kV低压侧三相短路电流的计算方法,即:在10/0.4 kV配变电所工程设计时,若高压侧部分相关资料不易获取,可利用二次侧额定电流与变压器短路电压即可计算出低压侧的三相短路电流。通过实例校验,结果表明,该近似算法可以用来校验相关导体和保护设备的合理选择。

In designing 10/0.4 kV distribution substation, it is essential to acquire the working parameters at the high-voltage side of the transformer. An approximate calculation method for threephase short-circuit current at the low-voltage side of 10 kV transformer was proposed by analyzing the calculation process of Ohm＇s method. The rated current at the secondary side and the short-circuit voltage of the transformer were used to calculate the three-phase short-circuit current. The results show that the approximation calculation method can be used to check the reasonable choice of the associated conductors and protective devices