Controller design with model identification approach in wide area power system

• Published in: IET generation, transmission & distribution Vol. 8; no. 8; pp. 1430 - 1443
• Main Authors: Kishor, Nand, Haarla, Liisa, Turunen, Jukka, Larsson, Mats, Mohanty, Soumya R
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.08.2014; Institution of Engineering and Technology; The Institution of Engineering & Technology
• Subjects: Applied sciences; BPS; centralised controller; Coherence; coherent generator; Coherent generators; complex stability radius; control system synthesis; Control systems; Design engineering; Disturbances. Regulation. Protection; Electric power generation; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Exact sciences and technology; feed supplementary control signal; fixed‐order controller design; H2 control; H2 norm; H∞ control; H∞ norm; input controllable variable; instrumental variable; integrated measurement‐based control; large electric power system; least‐square; local controller; local conventionally tuned power system stabiliser; Mathematical models; Miscellaneous; model identification approach; model‐based control; mutual information theory; Norms; Operation. Load control. Reliability; participation factor; Power networks and lines; power system control; power system identification; power system measurement; power system stability; Regulation and control; spectral abscissa; speed deviation difference; Stability; state‐space methods; state‐space two‐input two‐output model; stochastic processes; subspace state‐space based generalised Poisson moment function; synchronous measurement data; WAMS level model; wide area monitoring systems; wide area power system; power system measurement; state-space two-input two-output model; BPS; H2 control; wide area monitoring systems; centralised controller; H∞ control; model-based control; model identification approach; coherent generator; mutual information theory; power system identification; large electric power system; participation factor; subspace state-space based generalised Poisson moment function; stochastic processes; integrated measurement-based control; spectral abscissa; wide area power system; input controllable variable; feed supplementary control signal; power system stability; instrumental variable; synchronous measurement data; control system synthesis; WAMS level model; H∞ norm; least-square; fixed-order controller design; local controller; local conventionally tuned power system stabiliser; complex stability radius; speed deviation difference; power system control; H2 norm; state-space methods; H infinite optimization; MIMO system; Stabilizator; Input signal; Control system; Subspace method; Power system stability; Control synthesis; State space; Varying speed; Power system measurement; Model matching; Electrical network; Decentralized system; Least squares method; Electric power; On line processing; System identification; Mutual information; Large scale system; Information theory
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2013.0167

Using wide area monitoring systems (WAMS) offers a possibility for an integrated measurement-based and model-based control, which suits to the operation of large electric power system (EPS), along with online analysis. This study presents studies on fixed-order controller design through model identification approach with use of synchronous measurement data. Firstly, in the study, the coherent generator in each area of large EPS is determined by the mutual information theory. Then, state-space two-input two-output model is identified for the generator that has highest participation factor and thus referred as coherent generator. The model identification algorithms; least-square, instrumental variable and subspace state-space based generalised Poisson moment function are used. Next, WAMS level model is identified between the input controllable variable and speed deviation difference of coherent generator of each area. Finally, a local controller (decentralised) in each coherent area and a centralised controller at WAMS level between two coherent areas are designed by optimisation of the several design functions; H∞ norm, H2 norm, spectral abscissa and complex stability radius, as much as possible. These controllers feed supplementary control signal in addition to one fed by local conventionally tuned power system stabiliser. The centralised controller at WAMS level is demonstrated to stabilise the speed deviations of each generator between any two areas in the large EPS. The study is investigated with different input signal variables; ΔVref, ΔPm excited by different pattern of disturbances.