HIGH-VOLTAGE PROTECTION APPARATUS FOR CIRCUIT SYSTEM

摘要

A high-voltage protection apparatus for a circuit system, comprising: a self-locking circuit unit (42), a capacitive over-voltage detection circuit unit (46), a timing control circuit unit (44) and a logical operation circuit unit (48), wherein when the time at which an alternating-current input unit of the circuit system is in three-phase zero-off exceeds a pre-determined time or an input voltage of the alternating-current input unit exceeds a first pre-determined voltage, the self-locking circuit unit generates a first signal (b) for controlling the switching off of a main relay of the circuit system; the timing control circuit unit generates a second signal under the trigger of the first signal; the capacitive over-voltage detection circuit unit generates a detection signal (c) for indicating whether a capacitive voltage of the circuit system exceeds a second pre-determined voltage; and the logical operation circuit unit performs a logical operation on the second signal and the detection signal, so as to obtain a third signal for controlling the switching off and switching on of an auxiliary relay of the circuit system.