Optimization of electric thermal flow field in valve-side bushing of converter transformer based on capillary wick heat pipe

The valve side bushing of the converter transformer generates severe internal heat during operation, and the electric field distribution is extremely uneven. Under the action of high temperature and composite voltage, it further leads to electric field distortion. Given the excellent heat dissipation and temperature uniformity performance of capillary wick heat pipes, a heat dissipation technology was proposed for bushing with heat pipes. A multi-physics field simulation model of bushing with heat pipe was built based on COMSOL Multiphysics. The axial and radial temperature and electric field distribution of the capacitor core was analyzed. Further changing the parameters of the heat pipes and the type of bushing failure, the impact of different parameters of the heat pipes and the effectiveness of the heat pipe under bushing failure conditions was studied. The simulation results show that after the heat pipe is added, the maximum radial temperature and electric field inside the casing is decreased by 41. 06% and 30. 12%, respectively, and the axial temperature and electric field distribution becomes more even. The heat transfer performance of the heat pipe is the best when the working fluid of the heat pipe is deionized water and the porosity is 0. 75. Even if there is overheating in the bushing, the heat pipe can still lower the hot spot temperature and reduce electric field distortion. © 2024 Editorial Department of Electric Machines and Control. All rights reserved.