Deterioration diagnosis for insulators of high-voltage induction motors used in compressors by the optical sensor

摘要

Optical diagnosis for aged insulators of high-voltage induction motors used in compressors have been studied. The values of reflective absorbance at different wavelengths, 635nm and 830nm, are used as a diagnostic parameter. We found that the reflective absorbance correlates with the glass transition temperature (Tg,DMA) of the insulators, the correlation coefficient being about 0.95. The Tg,DMA of insulators is one of the most important parameter to evaluate the life of materials. In this diagnosis, the degree of deterioration of the insulators can be calculated quantitatively using the diagnostic master curve, which is obtained from accelerated heating experiments.