Signal selection and latency compensation in wide area controlled power system

Abstract

This paper presents a new approach for selecting signals for the monitoring and control of power systems over a wide area. The approach solves the twin problems of locating Phasor Measurement Units for observability and placing dynamic controllers for controllability using distinct techniques. The selected signals are used as the input and output for the centralized wide-area controller. The paper proposes a technique based on Principal Component Analysis for coherency identification to select signals for observability, and a novel method of dimension reduction by Sequential Orthogonalisation to select signals for controllability. Additionally, the paper considers a simple damping controller circuit that takes inputs from wide-area signals to control inter-area oscillatory modes using conventional power system controllers. The proposed scheme is tested on the modified 39-bus New England Test System under a variety of operating conditions, and the results show a significant improvement in the damping performance of the system. To account for network latency in the wide-area control network that interconnects geographically and electrically distant areas, the paper proposes a novel technique called Unique Characteristic Recognition method to develop a customized Wide Area-based Oscillation Control Scheme for a specific network. Time-tested network latency compensation methods are employed in the proposed technique.