| 摘要 |
PURPOSE:To suppress increase of DC current at the time of restarting a BPP by delivering a firing phase pulse for suppressing the DC current based on an interruption signal from a phase control pattern generating circuit for intermediate failure upon receiving an intermediate failure signal from the counterpart end. CONSTITUTION:The protective system for AC/DC converter employs interlocking protection (BPP restart) in which a converter is not stopped in the case of a light failure (intermediate failure) in an AC system but bypath pair operation is effected and a normal operation is reset upon release of failure. Upon receiving an intermediate failure signal 29A from the counterpart end, a phase control circuit 19A delivers a firing phase pulse 24A for suppressing the DC current based on an interruption signal from a phase control pattern generating circuit 30A for intermediate failure. Consequently, the DC current can be suppressed below the overcurrent withstanding capacity of the converter at the time of restarting the BPP. |
