BS PD IEC/TR 62271-307:2015
高压开关设备和控制设备. 额定电压高于1 kV并且不大于52 kV的交流金属和固体绝缘封闭的开关设备和控制设备型式试验有效性的扩展指南
High-voltage switchgear and controlgear. Guidance for the extension of validity of type tests of AC metal and solid-insulation enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV