Online Location Approach for Aged Segment of HVDC Cables Using Insertion Index Perturbation and Reflection Analysis

Due to the harsh operating environment, the issue of insulation aging of submarine cables in high-voltage direct current (HVDC) transmission systems has become prominent, and the location of aged cable segment is of great significance for maintenance. To solve this problem, the relationship between the incident and reflected signals within the cable with aged segment is analyzed, and a location approach based on reflection analysis is presented. Then, in response to the demand for online monitoring, a transient signal injection method based on insertion index perturbation is proposed, making the overall scheme able to be realized online. The effectiveness of the proposed scheme is proved by extensive simulations in PSCAD/EMTDC.