Study on breakdown characteristics of BOPP film under multi-frequency field strength

In this paper, the typical engineering application scenario simulation model of BOPP film is established, and the typical operating voltage waveform characteristics are obtained by simulation analysis. Based on this, the breakdown field strength test platform of the film under AC and DC composite voltage is established, and the breakdown field strength of typical size metallized film under different harmonic content and different harmonic times is measured. The test results show that the breakdown field strength peak of the metallized film is basically the same as that under pure DC voltage when the number of DC superimposed harmonics is not more than 5 times and the harmonic voltage is not more than 600 Vrms. Therefore, when designing BOPP film insulation, the peak operating voltage can be equivalent to pure DC voltage. Insulation design also needs to consider the overvoltage multiple requirements and insulation safety margin of the capacitor.