Power Electronics for Renewable Energy Systems, Transportation and Industrial Applications

Chapter 9Universal Operation of Small/Medium-Sized Renewable Energy Systems

Marco Liserre¹, Rosa A. Mastromauro² and Antonella Nagliero²

¹Christian-Albrechts-University of Kiel, Kaiserstr, Germany

²Department of Electrical and Information Engineering, Politecnico di Bari, Bari, Italy

9.1 Distributed Power Generation Systems

In recent years, the electrical power system (EPS) has been subject to a worldwide restructuring process. Indeed, deregulation and the advancement of technology have increased interconnection of distributed power generation units to the main grid. The constant growth of distributed power generation systems (DPGSs) presents an efficient and economical way of generating electric energy closer to the loads. Moreover, environmental concerns have encouraged governments and the scientific community to work together in order to maximize the use of renewable energy resources. The rating of DPGSs can vary between a few kilowatts to as much as 10 MW.

Various types of new distributed resources, such as microturbines, small hydro cells and fuel cells, in addition to the more traditional solar and wind power are creating significant new opportunities for the integration of DPGSs into the electricity grid. Voltage source converters (VSCs) employing pulse width modulation (PWM) techniques are often used to interface the DPGS to the grid [1 2].

One of the most important issues introduced by the growth of DPGS is the stand-alone operation mode. Improvements in power electronic ...