Simulated State Estimation Base On Phasor Measurement In Power System

With the gradual development of national economy, the scale of power system is rapidly increased accordingly, the framework and running way of power system are trending complexity. The Energy Management System (EMS) is the need of trend and state estimation (SE) is regarded as an essential part of Energy Management System (EMS). The algorithm of SE is related to the speed and precision of calculating directly. For a large-scale power system, the conventional state estimation methods have reached a stage in which substantial improvements in either speed or numerical robustness are unlikely. So we must open up new SE methods to adapt to the development of future power systems. With the gradual development of the GPS-based Phasor Measurement Units (PMU), they probably will be the one of main trend in the future because the model of SE based on PMU has obvious advantages over the centralized control for the large-scale interconnected system. Following aspects and works are done in this paper:The power system state estimation, the application and the present status of power system state estimation are discussed. The model of the power system state estimation is generalized. Some conventional power system state estimation are introduced and compared.The phasor measurement technology based on GPS is introduced briefly. The function of phasor measurement technology in the state estimation is also focused and studied, and how to add these phasor measurements into state estimation is introduced .This paper also introduce briefly that the application model of SE based on PMU in power system.Model of the hybrid state estimation based on phasor measurements are built.This model of algorithm in this paper that based on phasor measurements build a hybrid SE algorithm, which includes both nonlinear and linear SE: the algorithm, that not only enoughly use the voltage phasor of nodes with PMUs ,but also utilize efficiently PMU current phasor measurements is presented the improved algorithm.A hybrid SE in this paper is transforming the branch current phasors to the correlative node's voltage phasors, then current measurements can be utilizedefficiently in the nonlinear SE.The models and system are simulated byMATLAB in this paper. The results denote that the model of state estimation isefficient.