On the Simultaneous Estimation of Dynamic and Algebraic States in Power Networks via State Observer

This paper considers the problem of estimating the dynamic and algebraic states in transmission power networks. Specifically, we leverage a linearized, differential-algebraic equation (DAE) of power networks—also called descriptor system models—consisting generator’s dynamics, stator’s algebraic constraints, generator’s complex power, and the network’s complex power balance equations. The DAE is then combined together with a phasor measurement unit-based measurement model, which assumes that bus voltages and line currents are measured, to produce a semi-explicit linear DAE which is exploited to design a linear DAE observer to estimate the dynamic and algebraic states of power networks. Numerical simulations are performed using the IEEE 9-bus transmission system to analyze the performance of the proposed observer in estimating generators’ internal states and unmeasured bus voltages subject to both Gaussian and non-Gaussian noise.