The significance of detecting partial discharge
Conventional non-withstand voltage and withstand voltage tests are difficult to detect insulation defects such as partial discharge.
Partial discharge will lead to a vicious cycle of insulation deterioration and defects in power equipment, and in severe cases, it may even cause insulation accidents.
Detecting partial discharge can prevent sudden insulation damage accidents in power equipment during operation.
A Comparison of Electromagnetic Measurement and Sound Measurement
Electromagnetic measurement method
It is relatively sensitive to the change rate of the pulse and is more suitable for internal discharge in the medium.
It is not sensitive to surface discharge on bushings, terminals and insulators with lower discharge spectra; it is susceptible to external electromagnetic interference; it can precisely locate, but the resolution is not high, mainly due to the limitation of equipment accuracy.
The attenuation of the transmission process is relatively small.
Acoustic measurement method
It is relatively sensitive to the type of medium and is suitable for detecting air medium discharge.
It is more suitable for detecting surface discharges on bushings, terminals and insulators.
Susceptible to interference from mechanical vibrations on site;
The positioning accuracy is affected by internal reflection, refraction and other phenomena, but the requirements for equipment accuracy are relatively low.
The attenuation in the transmission process is significant.
Partial discharge detection strategy
The sole application of a certain detection method has certain limitations and cannot comprehensively, objectively and truly reflect the operational status of the inspected equipment. Sometimes, it may even lead to misjudgment.
Only by comprehensively applying various detection methods and conducting professional analysis of the test data through relevant software can the most objective assessment of the equipment’s operating condition be achieved, thereby enabling reasonable decisions to be made.
The combined acoustic and electrical test is the better choice for partial discharge detection of switch cabinets.
Post time: Mar-17-2026