State Observer for the Fourth-Order Model of a Salient Pole Synchronous Generator with Stator Losses and Partial Input Measurements

In this paper we study the question of how to reconstruct the state of a power system using Phasor Measurement Units. In our previous research we proved that this question has an affirmative answer imposing some rather strict structural assumptions: namely, neglecting the generator rotors saliency and assuming that the stator resistance of the synchronous generator is zero. It was shown in simulations that the performance of the proposed observer was sensitive to these assumptions, observing a transient quality degradation for realistic simulations not imposing these assumptions. Moreover, it was assumed in our previous work that the mechanical power and the field voltage are available for measurement, a scenario that is not always feasible. In this paper we accomplish two ambitious objectives with our new observer. First, we dot not impose the simplifying assumptions on the generator model. Secondly, we consider the more realistic scenario where only mechanical power is available for measurement. That is, we solve a problem of state reconstruction of a nonlinear system with partially known input measurements - that is well-known to be a very challenging task. Realistic simulation results illustrates the good performance of the proposed observer.