Superiority of partial discharge characteristics of cross-linked polyethylene nanocomposites over microcomposites for electrical insulation application

Partial discharge (PD) study is considered as an effective tool to evaluate the condition of electrical insulation. The PD test results for cross-linked polyethylene (XLPE)/silica microcomposite (30, 40, 50 wt%) and nanocomposite (1, 2, 3, 4, 5, 10 wt%) samples in comparison to virgin (0 wt%) samples is presented. It has been found that nanocomposite samples have lower PD formation, higher discharge inception voltage (DIV) as well as breakdown voltage as compared with virgin and microcomposite samples. From the results, it has been observed that XLPE/silica nano 5 wt% sample exhibits the lowest PD formation, the highest breakdown voltage and DIV. The breakdown resulted due to PD is shown using oscilloscope waveforms and optical microscopic images. Improvement in results is ascribed to decreased interparticle distance between two adjacent nanofillers and increased interactions at the area between nanofiller-polymer matrix. The possible mechanism for the improved results is proposed using plausible explanation.