为了有效地解决多绕组变压器建模复杂、复合短路阻抗计算时间长及多并联绕组间环流计算难等问题,结合由自感和互感描述的变压器等效电路模型,提出了一种基于等效单匝电感矩阵的多绕组变压器复合短路阻抗及多并联绕组间环流的求解方法。该方法通过等效单匝电感矩阵求解出所有两两绕组间的短路阻抗,并结合复合短路阻抗的定义和端口条件,在Matlab软件中编写相应的通用计算程序,可一次性求解出任一所需的复合短路阻抗及多并联绕组间的环流大小。最后,以某一实际12绕组变压器为例,采用所提方法对复合短路阻抗和环流进行了计算,并与试验结果进行了对比分析,结果表明,该方法能够准确地计算出各种短路工况条件下的复合短路阻抗及多并联绕组间的环流情况,可以满足工程设计的要求。
In order to solve the engineering problems,such as complex establishment of the multi-winding transformer model,long calculation time of composite short-circuit impedance and difficulties in calculation of the circulating current for parallel windings,a solution method for composite short-circuit impedance and circulating current in the parallel windings was proposed based on the equivalent single-turn inductance matrix and the equivalent circuit model of the transformer described by self-inductance and mutual inductance.In this method,all the short-circuit impedance between any two windings were computed by the equivalent single-turn inductance matrix.Combining the definition of composite short-circuit impedance with the ports' conditions,all concerned composite short-circuit impedance and the circulating currents could be calculated only once through compiling the corresponding general calculation procedure in Matlab.Finally,taking a twelve-winding transformer as an example,the results calculated by the proposed new method were compared with the testing ones,which indicates that the calculation results of composite short-circuit impedance can meet the engineering requirements.