提出一种基于复数域标幺化的配电网三相不对称快速分解状态估计算法。基于坐标变换的思想,引入基准相角进行复数域标幺化,对阻抗进行整体移相,减小R/X比值,弱化电压相角对有功、电压幅值对无功的影响,实现配电网状态估计的快速分解;根据网络特性,得出使得快速分解估计方法可靠收敛的最优基准相角的选取原则;为适应PQ快速分解状态估计模型,将电流幅值量测等效处理为功率量测。标准测试算例的仿真结果表明,所提快速分解状态估计方法在保证估计精度的同时,可改善配电网状态估计数值计算的稳定性,提高大规模配电网状态估计的在线计算速度。
A fast decoupled state-estimation algorithm based on complex normalization is proposed for threephase asymmetrical distribution network. Based on the coordinate transformation,an angle reference is introduced to implement the complex normalization for shifting the whole impedance phases to decrease the ratio of R/X,which weakens the effect of voltage phase-angle on the active power and the effect of voltage magnitude on the reactive power for the fast decoupling of distribution network state-estimation. The principle of optimal angle reference selection is obtained according to the network characteristics,which ensures the reliable convergence of the fast decoupled state-estimation algorithm. The current measurements are treated as the power measurements to fit for the PQ fast decoupled state-estimation model. Simulative results of standard test examples show that,the proposed algorithm improves the numerical computation stability of distribution network state estimation and enhances the online state estimation speed of large-scale distribution network,while guarantees the estimation precision.