What detection techniques can be used for partial discharge?

When detecting partial discharge in high-voltage switchgear, it would be easier if we could perform on-site operations without interfering with the power supply. The most practical method revolves around detecting different RF signals.
The combination of sensors ensures easy identification of different types of partial discharges. Partial discharge generates transient ground voltage (TEV) - high-frequency electromagnetic pulses. The TEV signal passes through the inner surface of the switchgear and escapes to the outside through openings (such as gaskets) in metal products. By placing the TEV sensor outside the switchgear to measure these pulses, partial discharge activity can be detected.
The TEV method is particularly effective in detecting internal partial discharge. The acoustic emissions generated by partial discharge activities are usually at frequencies that are too high in the human ear, namely ultrasound. As partial discharge deteriorates, the frequency sometimes decreases to an audible range. When there is an air path between the source and microphone, using an onboard ultrasonic microphone is the most sensitive method for detecting PD. Contact type ultrasonic sensors can be used for sealed chambers.
The ultrasonic method is particularly effective in detecting surface partial discharge and corona partial discharge.
Understand partial discharge monitoring
High voltage switchgear and cable failures may result in millions of repairs, replacements, and fines. However, most faults do not occur at once - they can be predicted through warning signals, especially partial discharge (PD).