基于相量量测的等式约束二阶段状态估计模型

利用PMU的量测信息实现系统的动态可观测，考虑PMU数据刷新时间快的特点，在R.F.Nuqui的动态监测模型的基础上建立了适合静态估计的基于等式约束二阶段估计模型。该模型将PMU和SCADA的量测数据共同用于非线性估计，采用零注入节点功率作为等式约束条件来提高估计精度，然后对非线性估计的结果和PMU的支路电流相量进行线性估计。模拟了当系统某节点负荷持续变化时，利用等效导纳法对非线性区域节点状态量进行估计,最后采用IEEE 14和57节点系统算例对提出的模型进行了验证。

Equality Constraints Two-Step State Estimation Model Based on Phasor Measurements

To make power system dynamically observable by use of the information measured by phasor measurement units (PMUs), on the basis of R.F.Nuqui’s dynamic monitoring model an equality constraint based two-step state estimation (SE) model that is suitable to static SE is established, in which the property of high PMU data updating speed is considered. In this model the measured data from PMUs and SCADA are adopted together in nonlinear SE in which the zero injection nodal power is taken as the equality constraints to improve estimation accuracy, than linear SE is carried out based on the results of above-mentioned nonlinear SE and branch current phasor measured by PMUs. A situation is simulated in which the nodal state quantity in nonlinear region is estimated by means of equivalent admittance while the nodal load of a certain bus continuously varies. The proposed model is verified by IEEE 14-bus system and IEEE 57-bus system, simulation results show that by use of the proposed model the accuracy of SE is improved.