| 摘要 |
PURPOSE:To make it possible to measure the partial discharge generating position of a cable regardless of a joint part, by a method wherein the difference in operation start times of each switching clutch elements is measured and the operational order of each elements is determined. CONSTITUTION:When discharge is generated at the point B of a first phase cable 11, it is detected by capacitors C1, C2 and impedances Z1, Z2 attached to a terminal part. In this case, because a partial discharge pulse reaches the terminal of the cable 11 at first, a switching clutch element SCR1 is triggered and operated through an amplifier AMP1 and an absolute value circuit 13 to bring the output IN1 of a gate element EOR to L from H, IN2 to H and output to H and counted by a pulse counter 16 through the driving of an oscillator 15. In the next step, the partial pulse reaches the terminal of a cable 12 and, therefore, the oscillator 15 and the counter 16 are stopped. The calculation value of said counter 16 comes to the difference of partial discharge pulse arrival times between the cables 11, 12. Therefore, the clutch element is operated by the discharge pulse reaching at first and the measurement of time difference is enabled. |
