Study on performance of developed and industrial HFCT sensors

Partial discharge (PD) plays a paramount role in determining system reliability. Exact detection and measurement of PD occurrence play a crucial role in high voltage (HV) apparatus operation and maintenance. To find better and cheaper ways to detect PD existence, many sensors have been developed. The high frequency current transformer (HFCT) sensors which are connected to the HV apparatus directly are considered to measure more PD information than others. A simple PD measurement sensor using a combination of MnZn and NiZn ferrite cores has been developed and compared with an industrial HFCT sensor in this paper. Both of two HFCT sensors are used to detect the same PD signals. The PD series and single PD pulse from the two HFCT sensors are sampled at different sampling rates and compared in both time and frequency domains. The Fourier transform is used to generate the frequency spectrum of measured PD pulses. The analysis shows the developed HFCT sensor is effective yet simple compared with industrial HFCT sensor. It is more suitable for PD study in the laboratory environment.