简答题The electricity used by the substation is generally () A、380/220 v. B、Three-phase four-wire system C、Neutral point directly grounded D、One or more transformers are used to supply power according to the importance of the substation简答题In a half-circuit breaker connection, when the bus fails, the power supply influence range is ( ). A、Does not affect the power supply B、Affects only a loop power supply C、All power D、Only short time power outages, before the repair can pour brake quickly restore power to the circuit operation