INTENSIFICATION OF PARTIAL DISCHARGES IN THE POLYMER INSULATION OF POWER CABLES UNDER THE INFLUENCE OF HIGHER HARMONICS AND THE FORMS OF GAS MICROINCLUSIONS

The factors affecting the intensification of partial discharges in gas microinclusions in polymer insulation of power cables are described. Such factors include the amplitude, frequency, and shape of the power supply voltage, as well as the size, shape, and orientation in the electric field of the microinclusion. Mathematical modeling shows the dependence of the field strength inside the microinclusion on its shape in the context of the possibility of reaching the gas breakdown field strength for the initiation of a partial discharge. It has been experimentally demonstrated that an increase in pulsations of the direct rectified voltage increases the intensity of partial discharges in the dielectric. It should be noted that the effects of higher harmonics on the insulation of power cables are additional to the effects of sinusoidal operating modes, and the appearance of harmonics during cable testing and development of recommendations for their operating modes is currently not regulated. References 12, figures 3.