Chapter 1 - Introduction

Abstract

Power systems have been undergoing a great transformation for the past several decades. Although they have been operated with very few changes since their inception in the early 20th century, recent developments in the communication and control domain, as well as the renewable energy revolution, made it inevitable to implement a wide-scale modernization in power systems. This would not only include how the measurements are made or transmitted to control centers but also how power is essentially generated and injected into the systems. Distributed generators, which are smaller than traditional synchronous generators, cause stability issues that are related to their relatively smaller inertia. Automatic generation control schemes that have been operating seamlessly for decades with large-scale synchronous generators cannot accommodate distributed generators without significant changes in control approaches. Furthermore, such distributed generators are almost always embedded in distribution networks, which are initially designed to accommodate loads. Until the introduction of distributed generators, it has been the common practice to have a clear distinction between generation, transmission, and distribution or consumption of electrical energy in the grid.