| 摘要 |
PURPOSE:To promptly disconnect a synchronous phase modifier front a power system before the synchronous phase modifier becomes a load to the power system when a field loss occurs due to the abnormality of an exciting system, etc., by providing a trip circuit which disconnects the synchronous phase modifier from the power system when a lagged-phase reactive power detector and stronger excitation detector operate. CONSTITUTION:When the exciting device 6 of a synchronous phase modifier 1 becomes defective and a field loss takes place in the phase modifier 1, the reactive power of the modifier 1 abruptly changes from an advanced-phase area to a lagged-phase area. Then, since the reactive voltage of the phase modifier 1 enters the lagged-phase area, a lagged-phase reactive power detector 13 is started and a trip circuit 14 discriminates (201) the abnormality of the phase modifier 1 front the output 111 of a stronger excitation detector 11 and the output 131 of the detector 13. Therefore, the emergency stop sequence of the phase modifier 1 which is not shown in the figure operates and promptly disconnects (202) the phase modifier 1 from the power system. |
