A Review on Condition Monitoring for XLPE-Insulated Subsea DC Dynamic Export Cables

Future floating wind power generation systems connected to high-voltage direct current (HVDC) transmission are expected to use dynamic direct current (DC) export cables to connect floating substations to the seabed. These cables will be permanently subjected to harsh marine conditions, raising concerns about their reliability. In this context, this article presents a comprehensive review and technical analysis of the currently available insulation condition monitoring (CM) techniques for cross-linked polyethylene (XLPE) cables, specifically evaluating their suitability for future DC dynamic export cables. The analyses indicate that the existing techniques are not entirely suitable for this application, particularly when it comes to online detection and location of water trees and partial discharges (PDs), which are expected to be the most significant and likely insulation degradation mechanisms in these cables. Therefore, this review seeks to inspire further research endeavors aimed at accelerating the development of DC dynamic export cable technology.