加权最小二乘状态估计量测权值计算的实用方法

分析了实际系统中直接影响加权最小二乘状态估计量测权值的因素,基于量测精度等级及满量程提出了设置量测权值的实用化方法,展示了实际系统中典型量测权值的标幺化数值,可以看出不同电压等级功率量测权值的差别以及电压幅值量测和功率量测权值之间的关系。使用文中方法计算得到的量测权值能更准确地反映量测精度,从而能够提高状态估计结果的准确性,模拟算例和实际工程应用验证了所述方法的有效性。文中还分析说明了计算两种派生量测权值的方法以及选取零注入量测权值的原则。

Practical Method for Calculating Measurement Weights in Weighted Least Square State Estimation

This paper analyzes the affecting factors of measurement weight and addresses a practical way to calculate the default weights based on the information of measurement precision grade and full scale. Typical per-unit weight values from actual systems are illustrated to show the great difference between power measurement at different voltage levels and the relationship between power measurement and voltage measurement. As the proposed method is based on available information that can well represent the precision of measurement, more appropriate weights can be generated and hence higher state estimation precision. The effectiveness of the proposed method is verified by simulated case studies. Furthermore, the method for calculating the weights of two kinds of combined measurement and the principles of setting proper weights for zero-injection measurement are briefly treated.