Can We Predict the Partial Discharge Inception Voltage in Electrical Asset Components Operating at Variable Pressure? An Innovative Answer

Estimating and measuring the partial discharge inception voltage, PDIV, in electrified transportation asset components is inevitable in order to evaluate both insulation system design and component reliability during operation. Variable pressure during operation complicates partial discharge assessment, since partial discharge inception voltage, as well as PD magnitude and repetition rate, depend on pressure. This paper deals with the validation of the new, approximate (heuristic) model for partial discharge inception voltage estimation at variable pressure. Applying the model first to a simple insulation system geometry, and then to a real component of an electrified transportation electrical asset, that is, an electric motor supplied by AC voltage. It is shown that based on a single PD measurement performed, e.g., at standard atmospheric pressure, SAP, prediction of PDIV at lower (or higher) pressure levels can be achieved successfully. The model is validated by an innovative analytics software which enables automatic extraction, from each PD measurement, of the information about the type of defect generating PD, that is, whether internal to insulation or on its surface.