Vertical Ground Electrode Fault Detection Using Surface Wave Time Domain Reflectometry (SW-TDR) Excited with a Horn Launcher

Vertical Ground Electrode Fault Detection Using Surface Wave Time Domain Reflectometry (SW-TDR) Excited with a Horn Launcher

연구 분야: Verification

학회: 2023 URSI International Symposium on Electromagnetic Theory (EMTS)

A grounding network is an integral part of an electrical power substation. It protects expensive equipment and provides safety to workers. This paper presents a Surface Wave (SW) Time Domain Reflectometry (TDR) technique for grounding network health integrity monitoring by detecting faults in vertical grounding electrodes. In SW-TDR, a fast rise-time pulse is applied using a horn launcher into the grounding electrode. The injected pulse travels along the electrode in the form of a transverse magnetic (TM) propagating mode and is reflected at any impedance mismatch, such as a break-point in the electrode. By investigating the reflected signal waveform, the mismatch location and severity can be identified. Theoretical expressions and simulation of the fields of the surface wave guided by a single electrode in a lossy media is presented. A single electrode system with a conical horn launcher is designed and analyzed using full wave electromagnetic simulation to evaluate the wide-band input impedance and then TDR response as obtained by applying FFT. The results show that the SW-TDR is capable of detecting break-points in a grounding electrode for a system bandwidth of 300 MHz.