Optimal placement of PMUs considering logical topology of communication medium power system observability

Abstract

A phasor measurement unit (PMU) has a unique ability of providing synchronized phasor measurements of voltage and currents. This ability distinguishes it from all other metering devices. It has been perceived that PMUs hold the capability of revolutionizing the way of power system monitoring and control. However, high per unit cost and challenges related to its communication system has made its judicial placement in an electric grid a significant issue. Therefore, in present work various issues regarding PMU placement are considered. First, Linear programming approach is utilized to find out optimal PMU locations in the given system. Since, PMU installation costs also comprises of PMU communication infrastructure. Therefore, a novel method is employed to find out feasible communication network structure for the given system. The data generated by a PMU needs a reliable and stable communication network. Generally, fiber – optic cables due their high channel capacity, low latency and immunity to electromagnetic interference have become the choice for PMU communication. Therefore, fiber optical communication is considered as communication medium in present work. In this thesis, it is assumed that the fiber – optic network runs parallel to the electric power network. Constant growth and uncertain nature of power system causes problem of congestion. Further, propagation delay associated with optical fibers is also a recent topic of concern. Hence, in order to optimize the congestion and the propagation delay, a logical topology is generally developed for the optical fiber networks. This thesis presents a mathematical formulation based on integer linear programming for logical topology designing. The feasibility of the proposed formulations is checked by applying it on few IEEE systems. Results so obtained, establishes the feasibility of methodology. Present thesis has considered different PMU placement and infrastructure issues independently, which will benefit planning utilities.