基于电磁–机械耦合原理的变压器三相不平衡运行绕组振动模–态特征

Mode-state Characteristics of Three-phase Unbalanced Operation Winding Vibration of Transformer Based on Electromagnetic Mechanical Coupling Principle

针对变压器三相不平衡运行所造成的绕组不平衡受力振动问题,研究变压器在不同运行模-态下的绕组电流、内部漏磁及振动特性。基于电磁原理建立变压器模-态分析状态方程,通过电磁-机械耦合求解绕组振动加速度,在此基础上构建变压器三维有限元仿真模型。仿真分析不同运行模-态下端口电流、磁密分布以及受力振动,研究变压器电磁参数与绕组振动特性的变化及其对应关系。搭建动模实验平台,测量在不同条件下绕组电流及振动加速度。对变压器不平衡运行的研究结果表明,20%不平衡度条件下,不平衡相绕组受力及振动加速度可增加1倍,三相绕组的不平衡振动加速度相差约2倍,严重危害变压器内部结构的稳定性。

Aiming at the vibration of unbalanced winding caused by transformer’s three-phase unbalanced operation, this paper mainly studies the winding current, internal magnetic flux leakage and vibration characteristics of transformer under different operation modes. Mode-state analysis state equation was established based on electromagnetic principle, and the vibration acceleration of winding was calculated through electromagnetic-mechanical coupling. On this basis, the three-dimensional finite element simulation model of transformer was built. The port current, magnetic density distribution and vibration characteristics of transformer under different operation modes were simulated. Meanwhile, the variation characteristics and corresponding relationship between electromagnetic parameters and winding vibration were studied. A dynamic model test platform was established to measure the winding current and vibration acceleration under different conditions. The results show that under the condition of 20% unbalance factor, the force and vibration acceleration of unbalanced winding can be doubled, and the difference of vibration acceleration among different windings caused by unbalanced operation is about 2 times, which seriously endangers the stability of transformer structure.