215 / 2022-03-14 19:29:00

Evaluation of breakdown performance of polypropylene films under multiple stresses for DC capacitors

breakdown performance，,polypropylene films,thermal aging,DC superimposed harmonic voltages,DC superimposed pulse voltages

Purpose/Aim

The capacitors used for the converter valve hall have to bear a variety of stresses during operation, resulting in insulation deterioration and even capacitor failure. The evaluation of the breakdown performance of polypropylene (PP) films under complex working conditions is of great significance for comparing the properties of different modified films and guiding the means for regulating the properties of PP films.

Experimental/Modeling methods

After thermal treatment, the composition, thermal properties and breakdown strength of the modified samples are tested. The effects of DC superimposed harmonic voltages of different frequencies and amplitudes are studied. Moreover, the breakdown strength under DC superimposed pulse voltages with different amplitudes and accumulation times is focused on.

Results/discussion

Aging treatment and complex voltage waveform reduce the breakdown strength of PP film. The observations/findings are in-line with already existing results, confirming the negative effect of working conditions on insulation performances.

Conclusions

The experiment results confirm the effectiveness of the modification method based on nano-micro structure optimization under different applied stresses.