This paper proposes a method for determining the phase where partial discharges (PD) occur based on a high-frequency equivalent circuit model of the cable. The high-frequency current transformer (HFCT) is employed for signal measurement. Since the PD singles are propagated as a travelling wave along the power cable, the HFCT can be used to detect electricity signal and determine where PD sources are taken place from the transmission lines. The conventional observations of PD signals via oscilloscopes are affected by capacitive effect (i.e., cross-talk). Measuring the polarity of the waveform can improve the accuracy of PD source determination which can be identified by an equivalent circuit model. From simulation and measurement results, the polarity of the waveform in the phase where PD occurs is just the inverse of the signal waveforms in other two phases. Furthermore, the crest value of the waveform, estimation of the power spectral density and average power are used to verify this new approach. Finally, the proposed approach can accurately determine the phase location of PD sources in the field under high noise environment.
|Number of pages||12|
|Journal||International Transactions on Electrical Energy Systems|
|Publication status||Published - 2013 Jan 1|
All Science Journal Classification (ASJC) codes
- Modelling and Simulation
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering