三相负载不平衡对变压器振动特性的影响研究

三相负载不平衡是配网中较为常见的问题。为研究三相负载不平衡工况下配电变压器振动特性，本文理论分析了铁芯和绕组振动特性及绕组振动传播特性；利用有限元软件分析了三相负载不平衡前后铁芯磁感应强度及绕组电磁力变化情况；搭建了变压器振动测式平台，分别采集变压器在三相不同位置单相带额定负载、两相带额定负载工况下的振动信号。研究结果表明：三相负载不平衡工况下铁芯中磁通密度基本不变，负载不平衡不会对变压器振动信号高频分量产生影响；不同位置的绕组振动对同一振动测试点影响程度不一样；三相负载不平衡程度相同，不平衡相发生的位置不同，对同一测点的影响程度不一样

Influence of three phase imbalance on vibration characteristics of transformer

Three-phase load imbalance is a relatively common problem in distribution network. In order to study the vibration characteristics of distribution transformer under three-phase unbalance condition, this paper theoretically analyzes the vibration characteristics of iron core and winding and the vibration propagation characteristics of winding, uses finite element software to study the variation of magnetic induction intensity and winding electromagnetic force when three-phase load balance and unbanlance. Meanwhile, a transformer vibration measuring platform is set up to collect vibration signals of transformer under rated load of single-phase and two-phase at different positions of three-phase. The results show that the flux density in the core is basically unchanged under the condition of three-phase load unbalance, and the load unbalance will not affect the high-frequency component of transformer vibration signal. The unbalance degree of the three-phase load is the same, and the influence degree of the unbalance phase on the same vibration measuring point is different under different locations.