基于场路耦合法的换流变压器匝间短路故障研究

Research on Interturn Short-Circuit Fault of Converter Transformer Based on Field-Circuit Coupling Method

提出了一种考虑场路耦合的换流变压器匝间短路故障暂态过程仿真的方法,该方法可有效解决短路故障过程复杂的电磁问题,获得故障过程中线端及各绕组的短路电流波形。文中针对某一台换流变压器匝间短路实例开展了仿真计算,通过外部电路设置开关闭合时刻来模拟短路故障的发生,并结合系统参数和故障时刻的初相角,获得线端的故障电流波形。计算波形与实际故障录波波形基本吻合,证实了故障发展过程的假设,表明了所提方法适用于变压器匝间短路故障暂态过程的模拟。

A method to simulate the transient process of interturn short-circuit fault of converter transformer based on field-circuit coupling mthod is presented,which can effectively solve the complex electromagnetic problems in the process of short-circuit fault,and obtain the short-circuit current waveforms of line ends and windings in the process of fault.An interturn short circuit case in a converter transformer is used for simulation calculation,the occurrence of short circuit fault is simulated by setting the switch closing time in the external circuit,and the fault current waveform at the line end is obtained by combining the system parameters and the initial phase angle of the fault time.The calculated waveform is basically in agreement with the actual fault recording waveform,which verifies the hypothesis of fault development process and shows that the proposed method is applicable to the transient simulation of transformer interturn short-circuit fault.