Application of wavelets to identify faults during impulse tests

Impulse tests are conducted on a transformer to reasonably demonstrate that the transformer could withstand voltage surges arising from lightning or switching. There have been several studies on the application of wavelets to identify faults during impulse testing. Most of these studies have utilized simulated waveforms in which the fault is introduced by a suitable mathematical model. In our previous publications, we have demonstrated the limitations of wavelets to detect faults using experimental work based on a model transformer and a low voltage impulse generator. In this paper we have used a new technique to simulate such faults on an actual transformer coil using a 50 kV impulse generator. This paper presents preliminary results of this research work.