| 摘要 |
PURPOSE:To obtain an interelectrode dielectric breakdown voltage of a circuit breaker under operation in opening state at plural points, by applying one shot of impulse voltage with a >=10ms long trailing edge once after the breaker is opened. CONSTITUTION:To obtain a >10ms long trailing edge, at an impulse voltage generating device 10, the values of a neutral point resistance 17 and a trail edge adjusting resistance 19 are made large, and the device 10 is provided with a charging switch 15, and after an capacitor 16 is charged up to a specific voltage, the opening point of the switch 15 is made different. When electrodes start parting at time T1 and a impulse voltage with a >=10ms long trailing edge is applied at time T2, an interelectrode dielectric breakdown occurs at point P1. If a discharging circuit is oscillatory, a discharging current is oscillatory and a current zero point is obtained. Then, a circuit breaker 3 obtains dielectric recovery and the voltage is applied again from the generating device for the impulse voltage with the long trailing edge to apply a voltage shown by point S2 to the breaker, causing a dielectric breakdown shown by point P2. Then, dielectric breakdowns occur similarly as shown by points P3-P6 to obtain plural measurement points by applying one shot of the impulse voltage. |
