Project title: Research and Development of PD Based, On-Line Motor Insulation Condition Monitoring System
The PhD study focuses on developing insulation condition monitoring system for Medium Voltage Motors served as cooling water pumps at nuclear power station. I used Fractal based Partial Discharge (PD) recognition technique to carry out the insulation fault recognition. In practical situation, the phase information of Phase-Resolved PD (PRPD) pattern is lost which increases the recognition difficulty. The proposed method used a Polar PD pattern (circular format of PRPD) to solve this problem. Fractal theory is an image processing technique and capable of distinguishing double-source PD defects. I did both laboratory experimental work and on-site test at several EDF nuclear power stations. Three PD geometries are designed in laboratory. Based on them, both single-PD defects and double-PD detects are tested and the proposed algorithm are validated. Then the proposed algorithm is applied to on-site test data. The recognition rate for single-PD defect can be over 94% and double-PD detects over 84%.