特高压直流分压器内部温度场结构优化设计

Optimized Design for HVDC Voltage Divider Internal Temperature Field

直流分压器是直流输电系统中不可缺少的主设备。目前直流阻容式分压器因结构和工作原理的原因,导致内部出现较大的温度梯度,影响了分压器的误差性能,同时增加了空心绝缘子发生污秽闪络的概率。针对±1 100 kV直流分压器的散热问题,文中进行了内部温度场的结构优化设计,同时在顶部增加散热结构,降低其温度梯度。最后利用Ansys Fluent软件对该结构设计进行温度场和热流场的仿真分析,结果表明:在27℃的环境温度下,与传统结构的直流分压器相比,在额定一次电流为2 m A,热流量为2.2 k W的情况下,其内部温度有明显的降低,最大温差可达到20 K。同时增加的散热翅片显著提高了分压器内部气体的循环流动,提高了散热的效率,优化后的结构满足散热的需求。

DC voltage divider is indispensable for DC power transmission system. Owing to its structure and principle, DC voltage divider has a great temperature gradient inside, which affect its error performance and increase the flashover probability of the hollow insulator. For the heat problem, this paper improves the structure of the ±1 100 kV DC voltage transformer＇s internal temperature field, while improving the cooling structure of the top, this design can lower its temperature gradient. Finally, Ansys Fluent is used to simulation the new design for the analysis of the temperature distribution and heat flux field, the results show that, in the case of the primary current is 2 m A and the heat flow is 2.2 k W, the new DC voltage divider internal temperature decreases significantly compared to the conventional structure at an ambient temperature of 27 ℃, the temperature difference can reach 20 K. The cooling structure of the top increases the gas flow inside the divider and improves the efficiency of the heat dissipation, this optimized design can meet the cooling requirement.