LOW VOLTAGE UNINTERRUPTIBLE SWITCHING METHOD FOR TRANSFORMER

摘要

PURPOSE:To provide a low voltage uninterruptible switching method requiring only one switchgear for switching the banks uninterruptibly. CONSTITUTION:A nonfuse breaker NFB is closed when the AC switch section 7 of a bypass circuit is opened, and the phase detecting circuit in a control circuit 8 detects phase rotation on input and output sides. Output voltage of an inverter circuit 5 is then converted to have same phase and magnitude as those of output terminal voltage. Subsequently, the AC switch section 7 is closed and the primary cut-out switch PC of bank B is opened thus feeding the loads in bank B with power from a switchgear S.