Elaboration of Suitable Sensors for PD Measurents Within Different Motor Insulation Configurations at Short Voltage Rise Times

Paper in proceeding, 2026

The challenge to develop more reliable electric motor design solutions capable of operating under stresses induced by the recently introduced new semiconductor technologies increase constantly. This paper continues previous efforts to compare and elaborate methods to identify and quantify PD activities in different motor insulation configurations within highly challenging voltage stress. Approaches for making suitable sensors for on- and offline PD diagnostics are proposed. Specifically, an electrical method based on high-pass filter connection, two different current transformers as well as two antenna solutions are compared when utilized on two types of test objects. Their performance is discussed focusing on strengths, disadvantages and limitations. It is found that the method based on high pass filtering combined with the modified signal processing method has shown the best performance, however the introduced UHF solution performed well also for shielded motor geometry. The results constitute a solid base for insulation system diagnostics and sensor performance.