Power system state estimation is a process to find the bus voltage magnitudes and phase angles at every bus based on a given measurement set. The state estimation convergency is related to the sufficiency of the measurement set. Observability analysis actually tests this kind of problem and guarantees the state estimation accuracy. A new and useful algorithm is proposed and applied in this pape...

In order to more effectively cope with the real world problems of vagueness, imprecise and subjectivity, fuzzy event systems were proposed recently. In this paper, we investigate the controllability and the observability property of two systems that one of them has fuzzy variables and the other one has fuzzy coefficients and fuzzy variables (fully fuzzy system). Also, sufficient conditions for ...

In the linear control theory, the observability Popov-Belevitch-Hautus (PBH) test plays an important role in studying observability along with the observability rank condition and observability Gramian. The observability rank condition and observability Gramian have been extended to nonlinear systems and have found applications in the analysis of nonlinear systems. On the other hand, there is n...

This paper deals with observability of affine discrete-time asynchronous switched systems, that is affine switched systems whose switching times may be different from sampling instants. Two observability notions are studied: pathwise observability and mode observability. We show that there exist some sampling frequencies that preserve pathwise observability if any subsystem is observable. Neces...

We consider observability for a class of piecewise-affine hybrid systems without inputs. The aim is to give verifiable conditions for observability in terms of linear equations and inequalities. We first discuss a number of important concepts, such as discrete-event detectability and trajectory observability. We give sufficient conditions for observability, observability in infinitesimal time, ...

In this paper, an efficient and comprehensive hybrid intelligent technique for the optimal placement of phasor measurement units (PMUs) is proposed to minimize the number of PMU installation subjected to full network observability. Three main purposes of PMUs output synchronous measurements are monitoring, control, and protection of power system. We have combined Binary Imperialistic Competitio...

The observability of discrete time nonlinear systems is studied. Criteria of observability are given in terms of codistributions. This leads naturally to decompositions similar to the ones known in the continuous time case. Some observability properties of invertible systems are also investigated. In particular, it is shown that, under regularity hypotheses, the weaker notion of forward-backwar...

Relative observability has been introduced and studied in the framework of partially observed discrete-event systems as a condition stronger than observability, but weaker than normality. However, unlike observability, relative observability is closed under language unions, which makes it interesting for practical applications. In this paper, we investigate this notion in the framework of coord...

We investigate different concepts related to observability of linear constant coefficient differential-algebraic equations. Regularity, which, loosely speaking, guarantees existence and uniqueness of solutions for any inhomogeneity, is not required in this article. Concepts like impulse observability, observability at infinity, behavioral observability, strong and complete observability are des...

The observability of discrete linear time-varying (LTV) systems with normbounded parameter uncertainties is analysed in this paper. Like in continuous case (Chung, et al., 1999), the sufficient conditions, which ensure the observability of the uncertain system, are proposed. In discrete cases, reconstructibility is no longer equivalent to observability, which results in the different form of eq...