| 摘要 |
PURPOSE:To suppress the excitation throw-in current regardless of the throw-in timing of a breaker by exciting the winding of a receiving transformer from secondary side with an active filter before throwing in the breaker on the power source side of the receiving transformer, and generating a magnetic flux having phase lag of 90 deg. behind system voltage in an iron core. CONSTITUTION:When a receiving transformer 1 is thrown in, the DC capacitor of an active filter 2 is charged first, and then a breaker 2A is closed, and the active filter 2 is connected to the secondary side of the receiving transformer 1. On the other hand, system voltage Vs is detected with a voltage detector 3, and is taken in a control circuit 2B, and the voltage VACF of the same phase as the system voltage is generated in the active filter 2, and is applied to the secondary side of the receiving transformer 1, and a magnetic flux having phase lag of 90 deg. behind the system voltage is generated in the iron core. Next, the agreement of the phases between the system voltage Vs and the voltage VACF of the active filter 2 is detected with a phase comparator 6, and a throw-in permission signal is given to the breaker 1A. |
