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.