Understanding of XLPE Cable System Commissioning using Partial Discharge Measurements during AC HV Tests

This paper is based on the work done by Altanova Group, India, and describes the process and procedures used in a Partial Discharge (PD) investigation on a cable circuit during the AC withstand test. The paper focuses on the two most common approaches employed, namely, soak tests and resonant tests. In the latter case, the paper describes two approaches to performing the measurements and the relative benefits of each. De-noising the acquired data using T-F map analysis is also described, and real-world examples are given in the two case studies. These detail EHV resonant tests, one performed where all the accessories were monitored simultaneously and another where each accessory was tested in turn before relocating the PD monitoring equipment to the next location. In both cases, the application of T-F maps shows how different PD sources, such as external corona, can be identified and hence segregated.