| 摘要 |
PURPOSE:To achieve reliable high speed throw-in operation without producing excitation surge, by synchronizing voltage induced in a main throw-in winding of transformer with the voltage of a main throw-in circuit then throwing the main throw-in winding into the main throw-in circuit. CONSTITUTION:A circuit breaker 9 is thrown in so as to detect voltage and phase of a mail throw-in circuit 2 through PD3. Then a stand-by circuit breaker 13 is thrown in with output voltage from a reverse conversion element 7 being maintained at a sufficiently low level. Thereafter, voltage across ternary winding 1C of a transformer 1 is detected through PT16, and a control element 8 is operated such that the voltage induced in the primary winding 1A has same magnitude and phase as those of the voltage across a main throw-in winding detected through PD3. Transient exciting current is detected through CT17 and a main throw-in circuit breaker 10 is thrown in at a time point when the transient exciting current is settled to steady exciting current corresponding to applying voltage. Finally, the stand-by circuit breaker 13 is opened to complete full throw-in operation of the transformer 1. |
