Experimental-Based model for Turn-to-Turn PDIV Prediction Dependent on Temperature

Abstract

Turn-to-turn insulation partial discharge inception voltage (PDIV) plays a crucial role in the design of the insulation system of inverter-fed motors for the automotive sector. This paper presents a turn-to-turn PDIV estimation model as a function of temperature, insulation thickness, and its relative permittivity for round and rectangular conductors. The model addresses constraints identified in other published methodologies, in that it does not require FEM simulation, experimental results as reference data, and γ or Schuman's constant adjustment. The model was validated with over 100 experimental self-measurements and literature results. For almost half of these, the PDIV value was estimated with an error of less than or equal to 5%, and the 87% of the estimated values did not exceed an error of 12%. This figure is in good agreement with other literature models. The maximum error obtained was 18%, however this can be attributed to the assumption of unknown insulation thickness and ambient relative humidity condition differences during experiments. By employing the model, coil winding designers or wire manufacturers can quickly and effectively estimate turn-to-turn PDIV at the required operational temperature for round and rectangular conductors.