Chapter 11. POLYPHASE CIRCUITS
THE LEARNING GOALS FOR THIS CHAPTER ARE:
Know the characteristics of a balanced, three-phase circuit
Know the basic wye and delta three-phase connections
Know how to calculate voltage and currents in balanced, three-phase circuits
Know how to calculate complex power in balanced, three-phase circuits
Wind Farms Turning a former waste site into a reliable source of renewable energy seems like a great idea—a real "win-win" for energy and the environment. Denmark has done just that with its Middelgrunden Wind Farm on a natural reef east of the Copenhagen harbor. Established in 2000 as the world's largest offshore wind farm, it consists of 20 turbines with a total rated power of 40 Megawatts. For more than 200 years, the reef had been a dumping site for harbor sludge and other contaminated waste. Today, airline travelers flying into Copenhagen from the north can view the visual impact of this renewable energy source as a recognizable tribute to Danish ingenuity.
Denmark has more than 6200 wind turbines producing an estimated 89 million kilowatt-hours of electricity each year. One of Denmark's largest industries, wind turbine manufacturing has a considerable export market worldwide. The environmental impact of wind farms is remarkable—avoiding tons of chemical pollution that would occur from conventional energy sources.
Renewable power generated by wind farms—despite ...