High voltage direct current (HVDC) cross-linked polyethylene (XLPE) submarine cable factory joint is the key equipment for developing long-length cables and achieving long-distance

large-capacity flexible direct current transmission. This paper reviews the research status of HVDC XLPE submarine cable factory joints from the perspectives of development history

key preparation technologies

and testing methods. In particular

the influence of vulcanization processes on the properties of factory joints and the space charge measurement of full-size factory joints are analyzed. The key technical challenges that need to be addressed in the current research of HVDC XLPE submarine cable factory joints are proposed. The analysis shows that factory joints

with their excellent electrical and mechanical properties

have become the optimal choice for long-distance HVDC XLPE submarine cable transmission. Optimizing factory joint preparation processes

including vulcanization pressure and temperature

can improve the electrical properties of the factory joints. Additionally

advancing space charge measurement techniques for HVDC XLPE submarine cable factory joints

such as pulsed electro-acoustic (PEA) and thermal step methods (TSM)

is a key research direction. This study can provide a reference for the designing

manufacturing and testing of HVDC XLPE submarine cable factory joints.