| 摘要 |
PURPOSE:To prevent short-circuit between taps by providing a commutation switch in series to a main contact bulb and connecting an impedance element in paprallel to such commutation switch. CONSTITUTION:A commutation switch KA and an impedance element ZA are connected in parallel and a main contact vacuum bulb HA and resistance contact bulb WA are connected in series to such elements. The commutation switch KB and impedance element ZA are connected in parallel and the main contact vacuum bulb HB and resistance contact bulb WB are connected in series to such elements. When the arc is extended in the bulb HA, the switch KA opens before the bulb WA opens, following the bulb HA and commutates a current to the circuit of element ZA. This current is detected by a current detector CA and abnormal condition of bulb HA can be detected. Thereby, the tap changer can be checked under the on-load condition and short-circuit between taps can be prevented. |
