| 摘要 |
<P>PROBLEM TO BE SOLVED: To make the open power failure of an AC power supply, which has a comparatively long time, ranging from several seconds to about ten seconds, an object of compensation by using an electric double-layer capacitor for an inverter DC power supply in a countermeasure device against the instantaneous voltage drop. <P>SOLUTION: The countermeasure device against the instantaneous voltage drop/power failure includes a main thyristor switch 40, installed between an AC power supply 10 and a load 20; an injection transformer 50; and an inverter 70 connected to a secondary winding 52 and having a DC power supply 60, compensates the amount of the instantaneous voltage drop of the AC power supply, by the DC power supply 60 at the time of the occurrence of the instantaneous voltage drop of the AC power supply 10, and then compensates the amount corresponding to an AC power supply voltage by the DC power supply 60, at the occurrence of the open power failure of the AC power supply 10. This device also includes an auxiliary thyristor switch 80 on the AC power supply side of the main thyristor switch 40, and a control circuit 90, in which the auxiliary thyristor switch 80 is held in an off state, at the occurrence of the instantaneous voltage drop of the AC power supply 10, and the auxiliary thyristor switch 80 is turned on, at the occurrence of the open power failure of the AC power supply 10. <P>COPYRIGHT: (C)2009,JPO&INPIT |
