Power electronics is an integral part of power processing and delivery from energy sources to utility supply and to power consumers. The demand for energy, especially in electrical form, continues to increase in order to improve living standards. Power electronics supports the efficient use of electric power.
Semiconductor devices are used as switches for power conversion and power processing, while solid-state electronics are used to efficiently control the amount of power and energy flow. Devices used in applications ranging from microwave ovens to high-voltage DC power transmission require higher efficiency and lower losses. New devices and power electronic systems are evolving to control power and energy even more effectively.
Power electronics already occupies an important place in modern technology and is revolutionizing the control of power and energy. As the voltage and current ratings and switching characteristics of power semiconductor devices continue to improve, their applications continue to expand in areas such as lamp control, powering motion control, factory automation, transportation, energy storage, multi-megawatt industrial drives, and power transmission and distribution.
The higher efficiency and tighter control capabilities of power electronics are becoming more attractive for motion control applications as they replace earlier electromechanical and electronic systems. Applications for power transmission and renewable energy include high-voltage direct current (VHDC) converter stations, flexible alternating current transmission systems (FACTS), static variation compensators, and energy storage. In power distribution, applications include dc-ac conversion, dynamic filters, frequency conversion, and custom power systems.
The Kyoto Protocol on the reduction of greenhouse gas emissions has led to a growing worldwide interest in renewable energy systems. Today, many renewable energy technologies are well developed, reliable, and cost competitive with conventional fuel generators. The cost of renewable energy technologies is are trending downward and are expected to decline further as demand and production increases. There are many renewable energy sources (RES), including biomass, solar, wind, mini-hydro, and tidal power.
However, this chapter will focus on solar PV and wind power because solar PV and wind power systems utilize advanced power electronics technology.
One of the advantages offered by renewable energy is the potential to provide sustainable electricity in areas not served by the conventional power grid. The need for power electronics is growing rapidly as the market for renewable energy technologies expands. The need for power electronics is rapidly increasing. Since most renewable energy technologies generate DC power, power electronics and controls are needed to convert DC power to AC power.