New type of pulse current sensors for on-line partial discharge monitoring

Pulse current sensors are widely used to extract partial discharge (PD) signals from transformers for on-line PD measurement, and excellent pulse current sensors can help the measuring system to enhance the anti-interference ability for on-line monitoring. Authors did experiments on three kinds of current sensors with their inner diameter 450 mm in order to detect pulse signals of transformer bushings. The sensors´ cores are individually air-core plastic pipe, ferrite bar and ferrite powder. Parameters of the sensors, including sensitivity and frequency band, are provided and analyzed in laboratory conditions. Finally, the large-scale current sensors of ferrite bar have been applied in a power transformer.