Application of Heat Pipe Technology on Averaging Temperature of UHV Converter Valve-Side Bushing

As a critical component of UHV converter transformer, the converter valve-side bushing plays a vital role in connecting HVAC and HVDC systems. Due to the poor radial heat dissipation of the UHV converter valve-side bushing, the overall temperature and electric field distribution are incredibly uneven, especially under the condition of high ambient temperature and heavy load. To improve the temperature distribution and transmission capacity of the UHV converter valve-side bushing, we proposed the heat pipe method of averaging temperature, whose main principle is to realize superconductivity by using the phase-change effect of working medium. An electro-thermal-fluid coupled simulation model considering phase-change effect is established for a +/- 500 kV converter valve-side bushing. Corresponding electric field distribution and temperature distribution are obtained under conditions of different carrying current. The results show that the conductor structure of the UHV converter valve-side bushing perfectly conforms to the structure of the heat pipe. Besides, the application of heat pipe technology can significantly reduce the hot spot temperature, average the axial temperature, and increase the current-carrying capacity of the UHV converter valve-side bushing.