Comparison of different methods for optimal placement of PMUs

Comparison of different methods for optimal placement of PMUs

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Comparison of Different Methods for Optimal Placement of PMUs A. M. Almutairi, Student Member, IEEE and J. V. Milanovi±, Senior Member, IEEE Abstract — The paper compares three different methods for optimal placement of PMUs. The objective of the placement methods is to provide the maximum observability information of the electromechanical modes of interest. The first method is based on the observability factor analysis, the second on the sequential orthogonalization algorithm and the third combines coherency identification technique with the observability factor analysis. The methods are illustrated on the New England test system and assessed by applying a wide-area controller (WAC) for damping electromechanical oscillations in the system. The WAC is designed in each case based on using different PMU placement method. The effectiveness of the controller in damping critical electromechanical modes in the system is assessed using both, small disturbance and transient stability analysis. Index Terms — coherency, phasor measurement unit (PMU), optimal PMU placement, observability, orthogonalization, wide- area control. I. INTRODUCTION t has been shown in the past e.g., [1], that when using remote (global) signals for a wide-area controller (WAC) the damping of the interarea modes can be highly improved. For such controllers, synchronized measurements at system buses are taken and supplied by Phasor Measurement Units (PMUs) . Due to the costs associated with the installations of PMUs, e.g., communication infrastructure costs, unit cost, installation cost, etc., their number should be minimized. In addition, by minimizing the number of the supplied measurements (input signals) to the WAC the complexity of controller is also reduced. The installed PMUs nevertheless should provide maximum observability of the system modes of interest, e.g. lightly damped or interarea modes. Therefore, the candidate locations for the PMU placement should be optimally selected to minimize the number of units installed to ensure sufficient supply of synchronous information about the modes of interest. In this paper three methods for optimal placement of PMUs are reviewed and compared. The objective of the three methods is to minimize number of placed PMUs while maximizing amount of information supplied by them. The information of concern here is the observability of the system electromechanical modes of interest. The approach of the first compared method is based on the observability factor (OF) A. The authors are with the School of Electrical and Electronic Engineering, The University of Manchester, PO Box 88, Manchester, M60 1QD, UK. (e- mail: a.almutairi@postgrad.manchester.ac.uk, milanovic@manchester.ac.uk). analysis [2]. The second method is based on the Sequential Orthogonalization (SO) algorithm introduced in [3]. The third method is a coherency identification technique combined with the OFs analysis. The methods are illustrated on the New England test system. Results of each placement method are used to design a wide-area controller. The closed-loop systems
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

Comparison of different methods for optimal placement of PMUs

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online