一种新的三绕组自耦变压器的非线性建模

自耦变压器的精确建模在分析变压器运行于磁饱和区域的特性时至关重要。从单相三绕组自耦变压器的电磁关系入手,推导出折算到高压侧的三绕组自耦变压器的等效电路。给出模型中的线性绕组漏阻抗参数和非线性激磁阻抗参数的计算方法,并详细介绍了利用磁等值回路图得到激磁电抗非线性电感的方法。然后给出了利用JA磁滞模型编程实现非线性电感的方法。最后通过FORTRAN语言在PSCAD中搭建三绕组自耦变压器模型。仿真结果验证了所建模型能够准确地反映自耦变压器的非线性特性。

A new nonlinear model of three-winding autotransformer

The precise autotransformer model is crucial to analyze the characteristics of the transformer in the magnetic saturation region. In this paper, starting from the electromagnetic relationship of the single-phase three-winding autotransformer, the equivalent circuit of three-winding autotransformer converted to the high voltage side is derived. Then, the calculation method of linear winding leakage impedance parameter and nonlinear excitation impedance parameter is given. And the method of obtaining the nonlinear inductance of magnetizing reactance by using the magnetic equivalent circuit is introduced in detail. Then the method of using JA hysteresis model to realize the nonlinear inductance is given. Finally, a three-winding autotransformer model is built in PSCAD by FORTRAN language. The simulation results verify that the proposed model can accurately reflect the nonlinear characteristics of the autotransformer. This work is supported by National Natural Science Foundation of China (No. 51677068).