Design Of 100kV Impulse Breakdown Test System And Investigation Of Breakdown Properties XLPE/MMT Nanocomposites

Polymer nanocomposites is based on polymer and its dispersed phase at least dispersed in matrix in one dimension with (1-100nm) nanometer scale. Compared with the traditional composites, the physical and chemical properties of polymer nanocomposites are much better and some special properties can be obtained due to nano-effect and the interaction between nano-dispersed phase and matrix at the interface, which provides the possibility to prepare high-performance and mlti-functional composites of a new generation.To meet the requirement of impulse breakdown test of film samples, a low energy single stage high voltage impulse generator was developed, and extinction of gap arc and discharging current across the gap were determined. To postpone arc extinction, bypass capacitor across the gap was proposed. Based on fundamental theory, the waveforms with arc extinction at the peak and the tail were given, the improvement of bypass capacitor on waveform was analyzed and optical value of bypass capacitor in different conditions was determined. According to experimental results, the low energy single stage high voltage impulse generator can provide 1.2/50μs standard lightening waveform with aptitude of 100kV, which meets the meet the requirement of impulse breakdown test of film samples.Based on the low energy single stage high voltage impulse generator we developed and the test transformer, negative impulse breakdown and AC breakdown tests of XLPE and XLPE/MMT were carried out, and the breakdown test results were statistically analyzed with Weibull distribution. By comparing the effects of different styles of MMT and the content of MMT on composites, the improvement of breakdown strength of composites were clarified compared with polymer matrix. The result of breakdown tests shows that the breakdown strength of composites with MMT treated by intercalation agent was higher than any other composite systems. By analyzing the effect of MMT content on breakdown strength of composites, it was found that the breakdown strength of composites reached the peak with MMT content with 1%. Compared with polymer matrix, the enhancement of impulse breakdown strength and AC breakdown strength reached 1.9% and 12.55% respectively.