基于线性Lagrange插值法的变电站IED采样值接口方法

随着电子式互感器技术的发展和IEC 61850标准的推广，变电站间隔层智能设备的交流采样技术将由传统的对模拟信号A/D转换技术变革为以太网通信技术。为了不改变传统保护、测控装置算法，分析了采用线性Lagrange插值原理对合并单元输入的采样值进行数据抽取的方法，进行了误差分析，并分析了谐波信号对插值算法的影响。最后简要介绍了该方法在新型数字化变电站测控装置中的应用，经测试，精度满足要求。

A Sampled Values Interface Method for Substation IED Based on the Linear Lagrange Interpolation Algorithm

With the development of electronic transformers and the extensive utilization of the international standard IEC 61850, the sampled values technology in IED in the substation bay layer will be developed from A/D conversion of analog signals to Ethernet communication technology. In order to apply the traditional algorithms in lED in the substation automation system, the linear Lagrange interpolation algorithm for sampled values from the merging unit is studied. The error and the effect of the harmonic signal on the interpolation algorithm are analyzed. Finally, the application and test results of the novel digitalized measuring and control device using the linear Lagrange interpolation algorithm are briefly described. The accuracy is satisfactory.