Simulation Study on Partial Discharge Production of XLPE Cable Considering Temperature

Partial discharge of cables is an important factor that causes cable insulation breakdown and affects cable service life. Partial discharge emission and partial discharge propagation process are the parts that must be considered in the study of partial discharge. The author found that the existing numerical calculation of partial discharge emission only considers the influence of field strength and voltage, but the temperature also has an important influence on the escape and emission of charge. Therefore, this paper proposes a calculation model of partial discharge emission considering the effects of temperature and field strength. Through simulation, the temperature of the cable in normal operation is 324.16 $\mathrm{K}\sim 327.64$ K. Since the field strength at the tip defect is inextricably related to the shape and size of the defect, this paper studies the field strength distortion of various size defects, and the maximum distortion field strength value is $1.62\times 10^{9}\mathrm{V}/\mathrm{m}$, and then the obtained temperature and field strength values were brought into the calculation model of partial discharge emission. It was found that the magnitude of current density at room temperature and operating temperature was 10
³
orders of magnitude different. The current density difference caused by the field strength is 10
¹
orders of magnitude, so as to obtain accurate cable partial discharge current density, which provides support for the research of cable partial discharge fine propagation model.