Observers for a special class of bilinear systems: design, analysis, and application

This paper presents full and reduced order observation strategies for a subclass of systems that are bilinear in the immeasurable states. Lyapunov analysis is carried out to derive the conditions for convergence of the observed states for all strategies. The full order observer is then utilized in the problem of bus voltage regulation effected by a STATCOM acting as a controlled reactive current source. Simulations results are presented to show efficacy of the observation strategy integrated with the nonlinear STATCOM controller with regard to bus voltage regulation in the presence of disturbances in load and uncertainty in system frequency.