Polypropylene foil response to voltage impulses

Electrical insulating materials used in the electric power engineering are exposed to various overvoltage phenomena during operation. Effects of voltage impulses with various front time on the breakdown voltage of the biaxially oriented polypropylene foil were studied. The front time of the test voltage impulses used in the experiment imitates atmospheric overvoltage phenomena in laboratory conditions. It is shown that the change of the front time of the test voltage impulses have no significant impact on the breakdown voltage of the tested biaxially oriented polypropylene foil. Statistical analysis shows that the measured values of breakdown voltage have a normal distribution.