Observability analysis and restoration for systems with conventional and phasor measurements

Korres, GN; Manousakis, NM

dc.contributor.author	Korres, GN	en
dc.contributor.author	Manousakis, NM	en
dc.date.accessioned	2014-03-01T11:47:07Z
dc.date.available	2014-03-01T11:47:07Z
dc.date.issued	2012	en
dc.identifier.issn	1430144X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/38087
dc.subject	Conventional measurements	en
dc.subject	Flow islands	en
dc.subject	Gram matrix	en
dc.subject	Observability analysis	en
dc.subject	Observability restoration	en
dc.subject	Phasor measurement units	en
dc.title	Observability analysis and restoration for systems with conventional and phasor measurements	en
heal.type	other	en
heal.identifier.primary	10.1002/etep.1684	en
heal.identifier.secondary	http://dx.doi.org/10.1002/etep.1684	en
heal.publicationDate	2012	en
heal.abstract	This paper presents an efficient and fast method, using topological and numerical procedures, for observability analysis in state estimation with phasor measurement units as well as conventional (SCADA) measurements. Power and current flow measurements are used to build topologically flow islands that, in turn, are used to construct a reduced network and an associated gain matrix. To build this reduced order gain matrix, boundary power injections, and voltage phasors at flow islands are considered. Observability checking is carried out analyzing the pivots encountered during the triangular factorization of the gain matrix, and the observable islands are identified in a noniterative manner, by performing back substitutions with its triangular factors. Additional measurements that will render the system barely observable are directly provided, using the triangular factors of a reduced Gram matrix associated with existing and candidate power injections and candidate phasor measurements at boundary buses of observable islands. The dimension of the gain and Gram matrix is equal to the number of flow islands and boundary measurements, respectively, which is relatively low even for very large systems, and that makes the proposed algorithms fast and computationally efficient. The IEEE 14 and 30-bus systems are used to illustrate the steps of the proposed algorithms. © 2012 John Wiley & Sons, Ltd.	en
heal.journalName	European Transactions on Electrical Power	en
dc.identifier.doi	10.1002/etep.1684	en