| 摘要 |
PURPOSE:To use a semiconductor switch in which a voltage between poles is twice or less as large as a system voltage. CONSTITUTION:An instantaneous voltage drop compensator 1 connected between a system A side and a non-utility generator G side uses a semiconductor switch SS in which a voltage between poles is twice or less as large as a circuit voltage, and connects in series with a breaker CB. When the system A side is instantaneously power interrupted to open the switch SS, the voltage between the poles is detected by a detecting.operator 2, a ratio to its time is measured, an open command is output from a sequencer 3 to the breaker CB by expecting a time delay until the breaker CB is actually opened so as not to exceed the voltage between the poles of the switch, thereby preventing damage of the switch SS having twice or less of the voltage between the poles as large as a circuit voltage. Then, complete opening of the breaker SS is detected, a close command is output to the switch SS for next connection. |
