Abstract
A novel online technique for monitoring the insulation condition of ac machine stator windings is proposed in this paper. The concept is to measure the differential leakage currents of each phase winding from the terminal box in a noninvasive manner to assess the insulation condition during motor operation. The conventional differential CTs used for phase fault protection can be replaced with high performance current sensors to measure the leakage current with higher accuracy. Indicators for insulation condition such as the capacitance and dissipation factor are calculated based on the measurements to provide a low cost solution for online insulation condition assessment. A simplified online insulation system model is derived for analysis and interpretation of the measured data. Experimental results on a 15-hp induction motor under simulated insulation degradation conditions show that the proposed technique is a very sensitive method capable of detecting incipient signs of insulation degradation.
| Original language | English |
|---|---|
| Pages (from-to) | 737-745 |
| Number of pages | 9 |
| Journal | IEEE Transactions on Energy Conversion |
| Volume | 20 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2005 Dec |
Keywords
- AC machines
- Dielectric losses
- Fault diagnosis
- Insulation testing
- Leakage currents
- Monitoring
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering