Improvement of the PEA system with High Spatial Resolution at High-Temperature Measurement

Abstrtlct- Partial disdlarge (PD) associated with higher voltages in inverter-driven moton has become a problem; one of the reduction eauses of PD-ineeption voltage is said to be the spaee &:barge that aecumulates in the winding eoating material, especially at high temperatures, and it is neeessary to investigate this aeeumnlation ebaraeteristie. However, the typieal thickness of the eoating material of the windings used in electrie vehides is about 30 p.m, maldng it dUDeult to measure the spaec charge distribution with the usual PEA (pulse electrostatie stress) method, wbieh has a spatial resolution of about 10 pm. In the present study, a thin P(VDF-TrFE) piezoelectric sensor was formed directly onto a ground eledrode deposited on both sides of sapphire glass, whieh is said to have good acoustie propagation Characteristics, by the spin eoating method, and used to obtain a po1ition resolution of about 2.5 11m at 80 degrees C. The resolution was sueeessfully improved signifieandy.