| 摘要 |
PROBLEM TO BE SOLVED: To provide an on-load tap changer that is free from occurrence of insulation breakdown even when being in a current carrying state before and after a switching behavior and is excellent in reliability.SOLUTION: A movable contactor M1, a current-limiting resistor R1, a protection switch RS1, and a first resistance vacuum valve W1 are sequentially connected to a tap T2 in series. Further, a movable contactor M2, a current-limiting resistor R2, a protection switch RS2, and a second resistance vacuum valve W2 are sequentially connected to a tap T3 in series. The resistance vacuum valves W1 and W2 are connected to a neutral point N. The resistance vacuum valves W1 and W2 perform connection and disconnection of the current-limiting resistors R1 and R2 to and from the neutral point N. The protection switches RS1 and RS2 connect the resistance vacuum valves W1 and W2 that are in non-current carrying states to a circuit before a switching behavior of a change-over switch S and disconnect the resistance vacuum valves W1 and W2 that are in current carrying states from the circuit after the switching behavior of the change-over switch S. |
