基于多物理场耦合的非晶合金变压器短路特性分析

非晶合金变压器具有显著的节能优势,但是抗短路能力不足。针对在实际试验研究中非晶合金变压器绕组短路系列故障设置困难问题,本文基于电磁场-结构力场-温度场的瞬态多物理场耦合理论,建立变压器有限元三维模型。仿真了低压侧出口三相短路条件下非晶合金变压器矩形绕组的短路特性,研究了非晶合金变压器发生短路时温度剧烈升高所带来的热应力对绕组形变的影响。并对单独电磁力作用和电磁力热应力耦合作用下的绕组应力和形变进行了对比,计算结果表明热效应会对变压器形变产生较大影响,造成矩形绕组多处严重变形损坏。短路温升是变压器变形损坏不可忽略的因素,同时也是提升变压器抗短路能力中需要重点考虑的问题。

Analysis of Short-circuit Characteristics of Amorphous Alloy Transformer Based on Multi-physical Field Coupling

Amorphous alloy transformer has significant advantages in energy saving, but its short-circuit resistance is insufficient. In order to solve the problem that it is difficult to set up a series of short-circuit faults of amorphous transformer windings in the actual experimental research, based on the transient multi physical field coupling method of electromagnetic field structure force field temperature field, a three-dimensional finite element model of the transformer is established, and the three-phase short-circuit condition of the amorphous alloy transformer is simulated For the first time, the influence of thermal stress on the winding deformation caused by the sharp rise of temperature when three-phase short circuit occurs in amorphous alloy transformer is studied. The winding stress and deformation under the action of electromagnetic force alone and electromagnetic force thermal stress coupling are compared. The calculation results show that the thermal effect has a great influence on the transformer deformation, and the transformer deformation damage is not obvious At the same time, it is also an important problem to be considered in improving the anti short circuit ability of transformer.