温度对换流变压器绕组端部电场分布的影响研究

Influence of Temperature on the Electric Field Distribution of the Winding End in Converter Transformer

为研究温度对换流变压器绕组端部油纸复合绝缘系统电场分布的影响,首先测量获取了-40^+50℃范围变压器油和油浸纸板的相对介电常数、电导率;在此基础上利用有限元法研究了交流和直流试验电压作用下500 kV换流变压器端部电场分布的温度特性。研究结果表明:温度通过影响油纸绝缘的介电特性而影响换流变压器绕组端部电场分布特性;换流变压器的出厂试验需考虑实际运行条件下内部温度的变化范围做出适当的修正。

In order to grasp the electric field distribution of the oil-paper insulation structure in converter transform-er at different temperature,the dielectric properties of transformer oil and pressboard are measured at the tempera-ture range of-40^+50℃.In addition,for the 500 kV converter transformer,the temperature characteristics of elec-tric field at the end of the winding under AC test voltage and DC test voltage are studied by finite element analysis.The results show that temperature affects the electric field distribution at the end of the winding by affecting the di-electric properties of the oil-paper insulation.In consideration of the temperature variation in the actual operation,the factory test of the converter transformer needs to be corrected.