| 摘要 |
PURPOSE:To make self-troubleshooting in a short time and to increase the system reliability, by detecting the voltage between electrodes of main and auxiliary SCRs, in the process that the harged electrode of a commutating capacitor charged with a prescribed polarity is inverted with an auxiliary SCR. CONSTITUTION:A semiconductor DC circuit breaker 3 is constituted by connecting a commutation circuit consisting of a commutation capacitor 12, reactor 13 and auxiliary SCR14, in parallel with a main SCR11 supplying main current. A commutating capacitor 12 is charged, a voltage across an auxiliary SCR14 is detected with a detection circuit 21, by taking into consideration the charging time determined with the capacitance of the commutation capacitor 12 and a resistance of the charging circuit 16, and if any failure is present, the SCR14 is triggered and the voltage across electrodes after the polarity inversion is detected, and if normal, the voltage across the main SCR11 is detected at a detection circuit 22, allowing to troubleshoot the semiconductor circuit breaker after and before the start of system operation from each detection signal. |
