Research and application of power cable insulation condition testing technology based on short-time AC oscillating wave excitation

Abstract

This paper proposes a short-time AC voltage (STAC)-based insulation testing method for power cable lines, addressing the critical issue of cable insulation damage caused by space charge accumulation under DC oscillating wave excitation and overcoming the limitation of excessively short peak duration in existing methods. Firstly, a modular STAC excitation power supply based on high-power DC-AC conversion is designed, with its basic principle and implementation details elaborated. By comparing the partial discharge (PD) characteristics of various typical discharge defects under STAC, DC oscillating wave, and power frequency voltage, it is verified that the proposed method exhibits superior power frequency equivalence compared to the traditional DC oscillating wave method.