New magnetic sensor for partial discharges measurement applied to HVDC constraints inside GIS


Partial discharges (PD) measurement is the most common way to detect and identify defects for Medium/High Voltage equipment. Inside a Gas Insulated Substation, conventional method and ultra-high frequency (UHF) are usually used to measure PD inside the equipment. Recently, a new PD measurement sensor namely magnetic sensor is proposed, based on current induction. It might be the compromise between conventional and UHF measurement.

The aims of this work were to study its behaviour and to compare its performances with other measuring methods. Two different defects (protrusion and floating-moving particle) were placed inside a real size GIS under HVDC constraints. Magnetic sensors were placed successively at several locations. UHF and conventional measurements were used as references. The impact of perturbations, external corona and earthing disturbance currents, on the performance of the different sensors was studied.

The sensitivity of the magnetic measurement system is quite high at least 5 pC, with a smaller dependence on location than UHF sensor (distance, angle, presence of spacer …). Magnetic sensor measurement is slightly more sensitive to external corona and earthing current. The patterns given by magnetic sensor are quite similar with the ones given by the other measurements methods.

Matthieu DALSTEIN, Thanh Vu-Cong,
Christian M Escurra, Armando Rodrigo-Mor, Frank Jacquier, Alain Girodet

Presented at ISH 2023