| 摘要 |
PURPOSE:To facilitate the diagnosis of the deterioration in the insulation of a coil by providing an electrode for detecting the deterioration in the insulation between a main insulating layer around a stator coil and a semiconductive protection layer which makes contact with the slot wall of a core through an insulating layer at the protection layer side. CONSTITUTION:A stator coil 1 is inserted into the slot 3 of a stator core 2, and a hole is covered with a wedge 4. The coil 1 is formed by laminating a main insulating layer 6, an electrode 8 for detecting the deterioration in the insulation, an electrode insulating layer 9 and a conductive protection layer 7 around a coil conductor 5. Lead wirings 10 are led from the electrode 8 to the exterior. The insulation deteriorating state is inspected by connecting a megger and a withstand tester between the terminal of the wirings 10 and the terminal of the coil conductor 5, not shown. Tan delta can be always measured by the current which flows through the electrode 8 during the operation. The state of the deteriorated insulation can be readily discriminated without disassembling a stator coil. |
