基于递推最小二乘法的变压器参数辨识

Identification of Transformer Parameter based on Least Square Method

提出一种变压器漏电抗的识别方法,该方法无需改变变压器低压侧的电流互感器配置,无需测量绕组电流,直接利用低压侧线电流,在分相列写回路方程的基础上,消去低压侧绕组环流的影响,利用递推最小二乘法识别漏电抗,解决了Y/Δ接线方式下三相变压器的漏电抗计算问题.讨论T型等效电路模型中漏电抗参数的可辩识性和算法的误差,给出一种提高识别算法准确性的改进方案,并对方案进行了验证.EMTP仿真结果表明,该算法能够正确识别各相的漏电抗,具有良好的应用前景.

This paper proposes an approach to identifying transformer＇s leakage resistance.Without changing current transformers＇ configuration of transformer low voltage side and without measuring winding current,the influence of winding current of low voltage side is eliminated by directly using the current of side line based on equivalent circuit equation.Leakage resistance is identified by adopting least square method,thus solving the problem of calculating leakage resistance of three-phase transformers under the mode of Y/Δ connection.This paper also discusses the way to identify leakage resistance parameters in the model of T equivalent circuit and algorithmic errors.A scheme which can improve the accuracy of identification is provided and is then verified by EMTP simulation.The result shows that this algorithm can identify leakage resistance of various phases with prosperous future for application.