EN 60909-3-2010 三相交流系统中的短路电流.第3部分:两个独立的同时对地短路,部分短路电流流入大地情况下的电流
Short-circuit currents in three-phase a.c systems - Part 3: Currents during two separate simultaneous line-to-earth short-circuits and partial short-circuit currents flowing through earth