In this paper the observer design problem for a class of nonlinear port-Hamiltonian system is addressed. The class of nonlinear Hamiltonian system is based on the structure of energy function where it is possible to pull the state apart at measured and unmeasured states which generates two interconnected Hamiltonian systems. Exploiting the properties of the class of nonlinear Hamiltonian systems a reduced order observation scheme is proposed. Finally the observer design proposed in this paper is evaluated in a magnetic levitator in order to prove its the convergence properties, also it is comparing the observer convergence characteristics and the observer performance among the observation schemes that are reported in the literature.

This article addresses the design problem of observers for the oscillator, focusing on the nonlinearities present in the model, which arise from the product between components of the state vector. These nonlinearities are particularly interesting because they allow obtaining an error dynamics that can be used to study the convergence properties of the observation scheme. In this sense, the design of a full-order observer is proposed, which is characterized by being a replica of the original system, with the addition of a correction term. Additionally, a numerical evaluation of the presented results is performed.

The availability of excitation controllers to enhance transient stability has regained significant relevance in recent years, due to the unprecedented ongoing changes in power systems. Yet, the practical deployment of many reported control schemes is hampered by the fact that their implementation requires the measurement of the full state vector. Our main contribution is to address this fundamental obstacle by proposing an observer-based excitation controller using modern phasor measurement technology. For this purpose, a linear time-varying observer scheme for the generator frequency and the internal voltage is derived. This observer is then combined with a classical passivity-based excitation controller. Stability of the resulting nonlinear observer-based closed-loop system is shown by deriving an ISS-based separation principle. The performance of the proposed approach is demonstrated via simulation example.

This article introduces an energy-based approach for modeling water distribution networks with faults. The flow in each network pipeline is described by the rigid water column model (RWC), which can be obtained by assuming that the walls of the pipelines are rigid and the flow is incompressible. The key feature of the proposed approach is the modeling of the interactions of the network components (pipelines, faults, and sources), which is done through the use of the graph theory and from an energy point of view. Three examples are given: a pipeline with a partial blockage, a pipeline with a leak, and a pipeline with both faults. The models resulting from this approach can be used for the implementation of realtime applications, for example, for fault diagnosis or for control of valves and pumps in case of faults.

This paper establishes a design and performance comparison between two different estimation techniques in a Single Machine Infite Bus (SMIB) system, these techniques are the Extended Kalman Filter which is a classic estimator that has been used in the power systems for almost forty years and a nonlinear observer whose design is based on nonlinear mathematical model.