配电变压器用漆包铜、铝扁绕组线高温蠕变行为研究

Research on High Temperature Creep Behavior of Polyesterimide Enamelled Rectangular Copper and Aluminum Winding Wires for Power Transformers

本研究对180级聚酯亚胺漆包铜扁绕组线(QZYB⁃2/180)和180级聚酯亚胺漆包铝扁绕组线(QZYB⁃2/180L)在不同温度和耐受应力条件下的蠕变行为进行了分析。蠕变试验结果表明,当蠕变试验温度为160℃时,通过对铜/铝扁绕组线的耐受应力、蠕变阶段、表面形貌、导体尺寸和电气性能的对比研究可以得到如下结论:①在蠕变试验温度为160℃时,铝扁绕组线的耐受应力明显低于铜扁绕组线;②在蠕变试验温度为160℃、耐受应力为35 MPa条件下,铝扁绕组线的蠕变行为比铜扁绕组线明显;③导体尺寸测试结果表明,相同试验条件下,铝扁绕组线试样截面尺寸收缩比铜扁绕组线试样明显;④直流电阻率计算结果表明,相同试验条件下,铝扁绕组线试样导电性能劣化比铜扁绕组线明显。由此可以推测出,在相同蠕变试验条件下,铝扁绕组线的抗蠕变性能明显劣于铜扁绕组线。

An experimental study on creep behavior of polyesterimide enamelled rectangular copper winding wire(QZYB⁃2/180)and aluminum winding wire(QZYB⁃2/180L)used in the dry⁃type power transformers was presented.The comparison of creep properties and electrical properties of copper and aluminum wires are investigated.The study on stress of creep curves shows that when the creep temperature is 160℃,the creep stress of aluminum wire is lower than copper wire.When the creep temperature is 160℃and the creep stress is 35 MPa,the creep resistance of copper wire is better than aluminum wire.The analysis of conductor dimension after creep test shows that the shrinkage of sectional dimensions of aluminum wire is larger than copper wire at the same creep test condition.The calculation of DC electrical resistivity proves that the deterioration of electrical conductivity of aluminum wire is more evident compared with copper wire at the same creep test condition.The study on creep behavior of polyesterimide enamelled rectangular copper and aluminum winding wires proves that the creep resistance of copper wire is better than aluminum wire at the same creep test condition.