Online Partial Discharge Monitoring and Failure Analysis Case Study of a 275 kV Oil Filled Cable Termination

This paper describes the process for online partial discharge monitoring of 275 kV oil filled cable terminations to inform dynamic operational decision making and replacement projects. It will cover six months of online partial discharge monitoring and correlation of results to operational data, network events and weather conditions. The paper will also outline results from a forensic dissection of the terminations in order to identify the source of the defects detected by the online partial discharge monitoring system and inform subsequent severity calculations. The business case for online monitoring will also be discussed as well as the advantages and challenges of online monitoring in transmission level voltage environments.