Thermal Characteristic Simulation Study of Multicolumn Parallel Zinc Oxide Arresters Under Extreme Operating Conditions

The arrester plays an important role in the protection of the DC transmission system, and its thermal characteristics under different operating conditions greatly affect its performance. To study the thermal characteristics of multicolumn parallel arresters under extreme operating conditions in a DC system, considering the influence of SF6 fluid, the structural parameters of the ±500 kV Niu Cong DC transmission project were applied for this research. Firstly, a 3D model of the four-column parallel zinc oxide arrester installed on the neutral bus of the ±500 kV Niu Cong DC transmission project was built in ANSYS to analyze its thermal conduction. Then, the electromagnetic transient model of the Niu Cong DC transmission system was established in PSCAD to study the withstood energy of a four-column parallel zinc oxide arrester under 22 typical fault conditions in three operation modes. Based on the extreme operating conditions obtained, simulations of steady-state and transient thermal characteristics were performed considering the influence of SF6 fluid flow on the heat dissipation of the arrester. Finally, the field-test temperature test on the four-column parallel zinc oxide arrester was carried out to validate the effectiveness of the proposed simulation model and calculation method, with simulation data matching well with the field-test data. The results also conclude the thermal characteristics findings to reveal the thermal conduction of multicolumn arresters under extreme operating conditions.