基于超定线性方程组模型的电网GIC计算方法研究

Research on algorithm of GIC based on overdetermined linear equations model

为提高电网地磁感应电流(Geomagnetically Induced Current)GIC的计算精度,提出了基于超定线性方程组模型的电网GIC计算方法。该方法充分利用已测量到的GIC数据,将实测数据建立的附加方程与理论计算模型结合起来对GIC进行计算和评估。推导了回路电流法和节点电压法的超定线性方程组模型,并使用最小二乘法对所得到的超定线性方程组数学模型进行求解从而得到流过变压器中性点的GIC。通过六网孔网络阻抗模型的算例对此方法进行了验证,并与传统模型方法的计算结果进行了比较,比较结果证明此方法简单实用,精度较高,更加切近实际,尤其在受现实条件限制而无法获取准确原始数据的条件下,更能体现出此方法的优越性。

To improve the accuracy of the calculation results of GIC,this paper presents an assessing method of GIC based on overdetermined linear equation model,which makes full use of the measured GIC data and combines the equations established from the measured data with the theoretical calculation model;it derives the overdetermind linear equations model about mesh impedance method and nodal admittance method and solves the overdetermind linear equations with least square method to get the GIC in the neutral of transformers.The method is shown and verified by an example of six meshes impedance model,and compared with traditional model and method.The results demonstrate this method is simple,practical and high reliability and it is more excellent especially on the condition of lacking of accurate raw data.