Design and Application of Corona Current Measurement System under High-Voltage Direct-Current Environment

Transmission line corona characteristic research is one of the key technologies in high-voltage direct current (HVDC) transmission project in our country. In order to analyze conductor corona discharge characteristic under HVDC environment, a corona current measurement system is developed. In this paper, based on the finite-element method, the structure of the measuring equipment is determined. The anti-interference technology of the measuring equipment is researched and applied for accurate measurement. Research results show that, the measurement system is immune to the effects from the external electromagnetic environment and can measure corona current accurately. The corona current signal collected by optical fiber communication technology is safe and reliable. The measurement system can be used to measure the wide frequency band corona current. Corona current of the positive pole is bigger than of negative pole with the same voltage grade, and this measurement system can be used to research conductor corona characteristic.