A Performance Comparison Study of Quasi-Dynamic State Estimation and Static State Estimation

Abstract

With the increasing number of installed phasor measurement units and other intelligent electronic devices, dynamic state estimation has become a possibility for power systems. This paper presents a comparative performance study between quasi-dynamic state estimation (QSE) and static state estimation (SSE). In this study, generators are modeled with governor, turbine, and exciter models, which capture the slow dynamics. The QSE adopts the full model of the generator incorporating the slow dynamics from the electromechanical transients in the rotor, control of the turbine, etc. SSE utilizes frequency domain models without dynamics, so it employs a simplified generator model. State estimation is applied to these two different modeling approaches, and an illustrative example is used to present the performance difference between these two state estimation methods. The results indicate that QSE is capable of providing more accurate information of the monitored system compared with SSE.