中文摘要：

以110/38.5/10.5 kV,63 000 kVA三绕组变压器为例,提出将限流电抗器与快速开关并联后串入变压器高压绕组的变阻抗变压器。建立Pscad短路仿真模型,发生短路故障时通过快速开关控制限流电抗器的投切实现限流;分析了变压器中压绕组出口三相对称短路时限流电抗器的限流效果。建立了变压器绕组轴向振动的“质量弹簧系统”,用以分析变压器绕组在轴向短路力作用下的轴向动态过程,可得绕组的动态位移、动态力、弯曲应力。基于二维轴对称磁—热—流耦合场有限元模型,计算变压器绕组温升。对比分析限流电抗器投入与否2种情况下短路动、热性能,结果表明：投入限流电抗器变压器可降低短路电动力冲击和短路温升,变阻抗变压器的动热性能均优于传统的变压器。

英文摘要：

Taking a transformer rated 110/38.5/10.5 kV and 63 000 kVA as an example, a reactor controlled by a paralleled high-speed switch is put forward to limit the short-circuit current. The reactor is in series with the high- voltage winding of transformer. A circuit model is established to analyze the transient short-circuit currents of the windings when the three-phase short-circuit fault occurs at the location of the termination of low-voltage winding. The dynamic force, displacement and bending stress of variable impedance transformer are analyzed based on the mass-spring system. A magnetic-thermal-fluid coupled model is applied to calculate the temperature rise of the transformer windings at the short-circuit operation. The research method is applied to energy-saving transformer and the short-circuit mechanical stability and the transient temperature distribution of current-limiting reactor in- putting or not are calculated. The results show that the mechanical stability and transient temperature distribution of energy-saving transformers is superior to the traditional transformer.