Determining the dynamic insulation resistance of DC cables used in photovoltaic systems under operational conditions

This paper investigates the effects of DC and soil properties on the insulation resistance of cables used in the PV industry. Based on standardized experimental tests, the temperature-dependent conductivity was measured, and therefore the temperature-conductivity relationship for each cable type is extracted. Based on the Arrhenius equation, a mathematical model was developed. This model allowed the simulation of the cable insulation resistance based on the thermal properties of the insulation material, surrounding soil, and the current passing through the conductor. The simulation provided insights into the dynamic changes of the insulation resistance based on the parameters mentioned above.