一种求解环网无功问题的状态估计方法

State Estimation Method for Solving Reactive Power Problem in Looped Networks

输电网存在大量环形结构,无功测量精度较低且时常出现不良测量数据,加权最小二乘状态估计方法易受残差污染影响,难以满足状态估计合格率考核的要求。基于正常测点的概念,建立考虑测量设备自身不确定度的测点评价函数,用来评价测点正常与否。并以异常测点数量最小为优化目标,考虑系统实际约束和潮流约束,建立新的状态估计模型,对比残差分析的不良数据辨识方法在求解速度和精度上具有显著优势。基于某市实际输电网模型和遥测遥信数据进行算例分析。计算结果表明方法提高了状态估计测点合格率指标,证明了方法的有效性。

Due to large amounts of circular structures existing in the power transmission network,low accuracy of reactive measurement and its frequent bad measured data,the weighted least squares state estimation method is so vulnerable to residual pollution that it can hardly pass the examination on state estimation qualification rate.Based on the conception of normal measuring point,a measuring point evaluation function was established in this paper,considering the uncertainty of the measuring equipment,in order to judge whether a measuring point is normal or not.Furthermore,a new state estimation model was set up under consideration of actual system constraint and power flow constraint,taking the minimal number of abnormal points as the optimization objective.Compared with bad data identification method used for residual analysis,the proposed approach had significant advantages in the respect of solution efficiency and accuracy.Analysis of an actual transmission network model as well as its telemetering and telesignalization data in a certain city indicated that the indexes for the qualification rate of state estimation measuring point were improved and the validity of the proposed approach was verified.