三绕组变压器低压绕组幅向短路力的计算方法

Calculation method of longitudinal short-circuit force in the low-voltage winding of three-winding transformer

阐述了低-中-高结构的三绕组电力变压器低压绕组幅向短路力的计算方法,即从磁势平衡原理出发,导出了求解该变压器最严重短路情况下低压绕组幅向力的计算模型,利用"场-路耦合"有限元方法计算了该模型的二维瞬态漏磁场,获得了低压绕组线饼的受力分布和瞬变曲线,并对受力最大的线饼进行了抗幅向失稳能力校核。该计算方法简化了传统计算电磁力复杂的计算过程,提高了计算精度。计算结果表明,该绕组具有足够的幅向机械强度,不会发生幅向变形、倒塌等破坏现象。

This paper introduces the calculation method of the longitudinal short - circuit force in the low - voltage winding of low - middle - high structure three - winding transformer, which deduces the calculation model of longitudinal short - circuit force of this transformer under the most serious circumstance. It also calculates the two - dimension transient leakage magnetic field of this model by ＂circuit - field couple＂ finite element method, and acquires the force distribution and transient curve of low - voltage winding and checks anti - longitudinal instability capability of the winding under the largest stress. This calculation method simplifies the process of the traditional complicated electromagnetic force calculation and enhances the calculation accuracy. Calculation results show that this winding has e- nough longitudinal mechanical strength which will not lead to damages, such as longitudinal distortion and collapse.