DC partial discharge detection and analysis techniques

This paper describes partial discharge (PD) detection systems being developed at Honeywell Federal Manufacturing & Technologies (FM&T) for use during in-process and final acceptance production-level DC hi-pot cable testing. The goal of this testing is to identify potential problems in cables during early stages of production as well as to assess insulation deterioration and aging in units removed from inventory for inspection. The test systems described employ partial discharge and leakage current detection circuits, high-resolution data acquisition systems, and data analysis and pulse characterizations algorithms. A novel low-noise amplification and detection circuit is presented along with data demonstrating a significant improvement in signal quality over earlier systems. Preliminary design concepts of research into the feasibility of using these data analysis techniques and finite element analysis (FEA) models to determine the nature of insulation defects based on the partial discharge signature are also presented.