Abstract: In view of the problems of difficult periodic state control and low operation and inspection efficiency of substation equipment, based on the digital twin theory, a digital model and system based on the operation and and maintenance of real substation equipment is constructed. Firstly, the digital twins, which can reflect the real state of three kinds of equipment, namely converter transformer, condenser and GIS, are set up on the information layer. Secondly, the substation equipment of digital twins is analyzed with the historical big data of converter transformer, condenser and GIS, and then the next state of the substation state is predicted according to the collected state data, operation and inspection data of substation for realizing the data fusion of the physical layer and information layer in the actual substation of substation equipment. Lastly, the substation equipment operation and maintenance are considered as the experimental objects, the embedded information and physical fusion system is used to integrate and synchronize the operation and inspection data of substation equipment, forming the final digital twin framework system of substation equipment operation and inspection. Research shows that digital twin technology can improve the intelligent degree of substation equipment operation and inspection, and provide theoretical support for future substation construction. 

Key words: digital twin, substation equipment, physical space, virtual space