电力变压器绕组电动力的分析计算

利用有限元算法分析了三相电力变压器绕组各线匝在不同运行模式下电动力引起振动。在“磁—路”耦合模型中 ,电路参数的不同取值对应于变压器的不同运行模式———空载、常态和短路。分析结果表明 ,内绕组在径向受到压力 ,外绕组在径向受到张力 ,内、外绕组轴向电动力比径向力小很多 ,而相邻线饼或线匝间存在相互挤压力。尤其在短路条件下 ,巨大的电动力将使变压器线圈产生变形 ,其局部或整体受到破坏 ,最后导致变压器发生故障。

COMPUTATION OF ELECTRODYNAMIC FORCE ON WINDINGS OF POWER TRANSFORMER

Based on finite element method (FEM), the vibration of power transformer windings caused by electrodynamic force is analyzed. The magnetic electric coupling model with different parameters corresponds to the different operation modes -- no load, full load and short circuit. The computation results illustrate that there exists press force in radial direction of inner winding, and extension force in radial direction of outer winding. There is little electrodynamic force in axis direction of both inner and outer windings. Moreover, there exists pushing force between adjacent pies or turn of windings. Especially, the enormous short circuit electrodynamic force will make the windings distorted, damaging part or whole winding, resulting in the fault of transformer.