非晶合金变压器矩形绕组辐向抗短路能力的校核模型

Check model of radial short-circuit withstand ability for amorphous alloy transformer rectangular winding

基于分枝型失稳理论,建立了非晶合金变压器矩形绕组辐向抗短路能力的有限元校核模型.通过压曲分析可以得到矩形结构线圈的极限压缩力及不同压缩力作用下的压曲模态.对几起非晶合金变压器内绕组的辐向短路耐受能力进行了校核,实验证明了所提计算模型的合理性.与此同时,对影响矩形线圈辐向抗短路能力的因素进行了研究.研究结果表明:撑条的最大间距是防止绕组局部屈曲的最关键因素,绕组内部多处的撑条处于完全失效的支撑状态是导致非晶合金变压器辐向短路强度不足的原因之一;变压器的辐向极限载荷与导线辐向厚度的三次方近似成正比,因此增加导线的辐向厚度对提高非晶合金变压器矩形绕组抗短路能力的效果较明显.

The finite element check model of the radial short-circuit withstand ability of amorphous alloy transformer rectangular winding is built based on the bifurcation instability theory. The buckling analytical method is employed to calculate the buckling critical loads and buckling modes under different compression forces of rectangular winding. The short-circuit withstand capability of several amorphous alloy transformer windings are checked, and the validity of the proposed computational model is proved. At the same time, the influence factors of radial short-circuit withstand ability of rectangular winding are studied. The results show that the maximal spacing of the spacers is the most important factor to prevent the winding from local buckling. A state of complete failure of many inner winding spacers is one of the reasons leading to the shortage of the radial withstand short-circuit ability of amorphous alloy transformer. The transformer radial limit load is approximately proportional to the cube of the thickness of the wire, so the short-circuit withstand ability of rectangular winding can be effectively improved by increasing the radial thickness of the wire.