| 摘要 |
PURPOSE:To prevent the occurrence of an overvoltage and voltage waveform distortion in a power system provided with phase modifying equipment through a circuit breaker by preventing the occurrence of low-order harmonic resonance after an accident is eliminated. CONSTITUTION:When an undervoltage relay 19 detects the occurrence of an accident, a converter controlling protective device 20 stops an AC-DC converter 1 and, at the same time, a circuit breaker controller 22 is actuated and a phase modifying capacitor is set to a prescribed value. The setting value of the phase modifying capacitor is decided in advance at a level at which no low-order harmonic resonance takes place after the accident is eliminated by performing simulation. |
