The Study of the Nanosecond pulse method to Detect Winding Deformation of Power Transformer

Winding deformation is one of the most common faults of power transformers. It may cause partial discharge, even leads to insulation breakdown. Winding deformation also may cause the decreasing of mechanical properties of winding. The study of high sensitive detection method has important significance for detecting minimal change of transformer winding. So authors propose utilizing the nanosecond pulse method to detect winding deformation. Through computer simulations, the parameters of the nanosecond pulse is studied intensively in this paper. By means of analysis, a impulse that has a wave front 5 ns ± 30% and impulse width 50 ns ± 30% has been defined as signal source. To verify the effectiveness of the method, a testing power transformer was detected with the way of the nanosecond pulse. Testing results may reflected winding deformation very well. At the same time, the repeatability is good at the frequency range from 0 to 80 MHz..