Power Electronics for Renewable Energy Systems, Transportation and Industrial Applications

Chapter 8Controllability Analysis of Renewable Energy Systems

Hossein Karimi-Davijani and Olorunfemi Ojo

Department of Electrical and Computer Engineering/Center for Energy Systems Research, Tennessee Technological University, Tennessee, USA

8.1 Introduction

In recent years, there has been an accelerated development in renewable energy sources, such as photovoltaic (PV) and wind energy, to meet the increasing energy demands of growing populations. Most installed wind turbines are variable speed turbines, actuating doubly fed induction or synchronous generators in the kilowatt and megawatt ranges [1–3]. As many of the large wind turbines are located offshore, there is a need for robust machine and converter technologies that will require little maintenance. Since doubly fed induction and synchronous machines use brushes and commutators, which require frequent maintenance and replacement, new electric machine structures to replace wind generators are under investigation. The interior permanent magnet (IPM) machine is one such machine, with a considerable potential for wind power generation. This is because brushes and commutators are not required and there is no field winding copper loss since the excitation of permanent magnet is buried in the rotor. The IPM also offers better efficiency compared to other machines, although it is more expensive.

It is anticipated that microgrid systems consisting of many renewable energy sources, including IPM generators, serving autonomous ...