Modeling and Measurement of Internal Partial Discharges in Voids Artificially Made within 3D-Printed Polylactic Acid (PLA) Block

A well-known symptom of the aging phenomenon in electrical insulations is partial discharge (PD) which can occur in all media. Internal PDs in solid dielectrics occur in air-filled voids which are difficult to eliminate thoroughly and may appear simply during the manufacturing process. Although much research on PD measurement for solid dielectrics has been conducted, the modeling of PD based on a priori experiment is not investigated sufficiently. In this paper, a finite element analysis (FEA) model for internal PD in an air-filled cylindrical void inside a solid dielectric (case 1) under 60 Hz sinusoidal voltage is developed. The experiments are conducted to provide a basis for the estimation of parameters in the FEA model. The findings, then, would be used to investigate the prediction of PD behavior in another case study (case 2). In each case, a cylindrical void was artificially made within a 3D-printed polylactic acid (PLA) block. Then, phase-resolved partial discharge (PRPD) patterns were measured for the mentioned samples. Using deterministic PD measurement data for case 1, an FEA model was developed. This model will help us understand and explain internal PD behavior for case 2 with another size of void and a different insulation size. The results show acceptable agreement between the predicted and the measured PD activities. An accurate prediction of PD behavior only through simulation is a cost-effective and time-efficient approach to assess the reliability of insulation systems.