Preliminary study on partial discharge detection technology for HV switch cabinets, part 2: acousto-optic and electromagnetic composite sensing

Rapid and accurate detection of partial discharge (PD) of metal enclosed AC switchgear (HV switch cabinet for short) is of great significance for safe operation of the power grid and high reliability of power supply. The existing methods such as transient earth voltage (TEV), ultra-high frequency (UHF) and acoustic emission (AE) methods still have shortcomings, and the optical pulse method has not been applied yet. Additionally, due to mutual independence, heavy workload, low efficiency and measurement limitations of testing equipment, as well as the single criterion of signal source, technicians have great doubts about whether there are insulation defects in the interior of switchgear cabinets. Therefore, in this paper, an integrated composite sensor for HV switchgear cabinet is designed and its installation method is given. The preliminary experimental study in the laboratory shows that the designed sensor can measure ultrasonic, optical pulse, transient ground voltage and UHF signals at the same time, which provides a new research direction for the effective detection of partial discharge signals of high voltage switchgear cabinets.