An efficient methodology of simultaneous three-phase withstand voltage and sensitive partial discharge testing of medium voltage power cables

Abstract

Withstand voltage tests and partial discharge (PD) measurement are widely accepted as indispensable techniques for assessing the insulation condition of power equipment. To reduce testing time, a favorable tool that can perform insulation tests simultaneously for three-core medium voltage (MV) power cables is urgently needed. This study aims to develop a high-efficiency solution for this purpose. The proposed methodology’s topology and operation principle are presented and illustrated, which can be used to conduct three-phase withstand voltage tests and sensitive PD measurement of MV cables simultaneously under different excitation voltages. Circuit analysis and parameter optimization are carried out to adapt the system to the application. Thus, the proposed methodology is implemented, and a prototype is built. A new method for achieving high sensitivity in screening PD pulses is proposed, and some experimental tests on a three-core MV power cable with artificial defects are performed to validate the effectiveness and practicality of the proposed methodology.