Electromagnetic transient interference measurement system of UHV Fixed Series Capacitors at high potential and EMI characterization

Abstract

Switch operation and bypass gap sparkover in Ultrahigh Voltage (UHV) Fixed Series Capacitors (FSC) produce fast on-platform transient overvoltage in primary side and couple into the protection and control system of secondary side. To understand the electromagnetic interference (EMI) characteristics of UHV FSC in both primary and secondary side, we focus on high-potential and on-platform primary-side overvoltage and secondary-side disturbance measurement on a life-size experimental platform. Firstly, we set up a Series Capacitors Electromagnetic Transient Interference Measurement System (SCEMS) and demonstrated its efficiency by a series of laboratory performance test. Secondly, by isolating disconnect switch of the UHV FSC experimental platform, the necessity and effectiveness of shielding for on-platform SCEMS was verified, and primary-side overvoltage and secondary-side disturbance were obtained. Lastly, characterization of EMI data in amplitude, time and frequency domain was analyzed, and statistical distribution of P-P (peak to peak) value described. The measurement system, SCEMS, and the high-potential measurement technique in UHV FSC, where applicable, are to extend to Series Capacitors (SC) at different voltage levels, regardless of fixed capacitors or controllable capacitors. Experimental data is suitable to use by designers and engineers in EMC solutions, insulation cooperation, and equipment arrangement optimization.