In terms of locating the source of partial discharge, transient earth voltage (TEV) detection is well recognised to have advantages over electrical methods. A variety of sensors are suitable for on-line PD testing of outdoor equipment, including ultra-high frequency (UHF) and radio frequency (RF) antenna, transient earth voltage (TEV) sensors, acoustic emission (AE) sensors and high frequency current transformers (HFCT). Among these, UHF, TEV and AE are usually adopted to detect PD activity and to determine the partial discharge (PD) location. These three detection methods display similar response to PD activity. The main characteristic shown is multi-oscillation and gradual attenuation.
- PD pulses
- transient earth voltage detection