Technical Progress, Challenges and Prospects of HVDC Cable Accessories: A Review With Chinese Practice Insights

ABSTRACT With the development of deep‐sea wind power and large‐scale onshore clean energy, the global demand for higher voltage level DC cable power transmission technology has become increasingly urgent. This paper systematically reviews the technical advancements in high voltage direct current (HVDC) cable accessories, addressing design challenges of terminations and joints, insulation material performance, manufacturing processes for large‐scale components, standard frameworks and long‐term reliability. The core challenges in HVDC accessories are identified as conductivity matching of insulating materials, interface electric field regulation and multi‐field coupling reliability, requiring synergistic optimisation of electrical, thermal and mechanical behaviours through the modification of rubber materials, interfacial compatibility and multi‐physics field modelling. Silicon rubber and ethylene propylene diene monomer made in China have achieved electrical properties comparable to international standards, yet breakthroughs in tear resistance, process consistency and environmental sustainability remain critical. The injection moulding defect control and uniform moulding process of large rubber and epoxy parts demand further improvement. The standard system in China needs to be strengthened in terms of systematic certification and long‐term reliability evaluation. Future research should prioritise eco‐friendly material development, intelligent monitoring technologies and multi‐field coupling ageing life prediction to enhance the reliability of HVDC cable systems under extreme voltages and complex operational scenarios.