Fast computation of electro-thermal coupling field of ± 400 kV converter transformer valve side bushing based on proper orthogonal decomposition method

• Electro-thermal fields of bushing under different operating conditions are computed. • Adding the steady state results in the snapshot can effectively reduce the error. • Reduced-order model improve computational efficiency ensuring computation accuracy. The digital twin technology plays a crucial role in enabling the intelligent operation and maintenance of power equipment, as well as facilitating the digital transformation of the power industry. High voltage (HV) converter transformer valve side bushing is a critical equipment in high voltage direct current (HVDC) transmission projects and the coupling effect of its multi-physical fields determine the operation state of the equipment. Therefore, there is an immediate necessity to develop key digital twin technology for HV bushings, allowing for real-time monitoring of multiple physical field to support their reliable operation. The paper adopts the finite element method to construct a model for electro-thermal coupling field of the converter transformer valve side bushing. By solving electro-thermal coupling finite element equations, snapshots are obtained and electro-thermal coupling field of the bushing is efficiently computed using singular value decomposition and proper orthogonal decomposition (POD). The results demonstrate that electro-thermal coupling field distribution obtained through the reduced-order model closely matches that computed by commercial software, significantly reducing the required computation time. This research validates the effectiveness of utilizing POD for fast computation and real-time simulation of electro-thermal coupling field of HV converter transformer valve side bushings.