油浸纸板分布对±500 kV换流变压器饼式绕组温升的影响分析

摘要

油浸纸板在变压器中除支撑、绝缘作用外,还为油流散热提供导向通道,其分布位置直接影响换流变压器的温度分布及热点位置.分析了油浸纸板分布位置不同对换流变压器内部温度的影响,以一台±500 kV换流变压器为例,首先基于磁场仿真模型计算得到了铁心和绕组损耗;再以绕组损耗为热源,采用Fluent模拟了换流变压器内部散热的热流耦合过程,得到了流体场和温度场分布;并将软件仿真结果与经验公式结果对比,验证了软件仿真结果的合理性.最后通过改变导向分区、角环对数,探讨理想的纸板放置位置,从而得到更均匀分布的温度场.经分析,合理的导向分区与角环分布可以明显降低热点;并使温度分布更加均匀.分析结果可为变压器设计提供分析和指导;同时进一步讨论换流变压器中理想的油浸纸板位置.%Oil-impregnated pressboard which supports windings,has insulation function, and provides the fine oil-way for insulation oil,can affect temperature field directly in convert transformer.Taking the ±500 kV convert transformer as an example, the location of pressboard which has influence on temperature field was analyzed and discussed.Firstly,the losses of the core and windings were calculated based on the magnetic model.Secondly, with the magnetic field and winding losses as the heat sources,the Fluent was used to simulate the heat flow cou-pling process and the fluid and thermal field is obtained,then the verifications of the simulation results were con-ducted by the comparison between the empirical formula results and the software simulation results.Finally, the factors influencing the temperature field such as guided partition number and ring number were analyzed.The result can guide to design the transformer,and be helpful to get the perfect location of pressboard.