The Electrical and Thermal Multi-Physical Field Simulation of HVDC

Abstract

With the rapid development of HVDC transmission technology in China, commutation technology is becoming more and more localized. As the core equipment of the converter station, operation status of the converter valve tower is directly related to the safe and stable operation of the converter station. The valve tower structure of converter station is complex and precise. The electrothermal performance of valve tower under high voltage and high current operation environment is the focus of the engineering designers. In this paper, the three-dimensional electric field simulation model for converter station valve tower is established. The distribution of electric field on valve tower and fittings surface is obtained under operation conditions, and the distance of key discharge path is calculated by flashover checking. Considering eddy current heating under high current conditions, the temperature distribution on complex fittings surface of valve tower is checked and calculated. On the basis of the simulation of electrothermal physical field, the field test of ±500kV valve hall is carried out by using the ultraviolet imager and infrared thermal imager. The results show that the temperature and electric field are the hottest points in the simulation results under the actual operating conditions, which coincide with the field observation position, and prove the validity of the simulation calculation of electrothermal physical field. Based on this, the discharge path of valve hall is checked by electric field using theoretical formula. The research results of paper have certain theoretical guidance value for operation and maintenance of valve hall of converter station, especially for the overheating of valve tower after the capacity of HVDC transmission line is increased, which provides better visual theoretical checking calculation method.