Effects of temperature gradient on transient electric field under DC voltage reversal

Temperature gradient through the cable thickness occurs due to Joule heat arising from the electric current in the HV cable conductor, which tends to affect the injection and migration of charge. Consequently, based on the pulsed electroacoustic (PEA) method, space charge accumulation and maximal transient electric field distortion were studied under different temperature gradient during applied 50 kV/mm DC stress together with the applied voltage reversal. The experimental results show that the maximal steady-state electric field appears near the low temperature electrode when temperature gradient and DC stress are imposed upon simultaneously. However, the maximal transient electric field appears near the high temperature electrode when temperature gradient and voltage reversal are imposed upon.