With a focus on harvesting the greatest amount of energy from wind power, it is easy to jump to conclusions that turbine manufacturers are turning to permanent magnet generators (PMG) as their best response to better annual energy production (AEP). Yet, is that all that stands behind the selection of this technology? Jussi Vanhanen, Director of Marketing and Sales, shares his recent discussions with wind turbine manufacturers.
“It is an undeniable fact that PMGs have been proven to be the best technology available today to increase annual wind turbine energy production and has grown in popularity due to its contribution to AEP performance,” Jussi says.
PMGs ensure fewer failures as there are no moving parts subject to wear, and PMG-based turbines require significantly less maintenance. Additionally, PMGs excel at efficiency, demonstrating higher efficiency rates at partial loads where they spend the greatest number of their operating hours. This results in their proven higher efficiency curves. In an independent study by NextWind’s Rain Byars, PMGs result in 1.4-6.9% more energy on a consistent basis per year, depending on the wind class. And this advantage becomes clearer at lower wind speeds because they are able to add more power to AEP rates when operating at partial loads.
“Today’s turbine manufacturers, however, first select the type of converter that is easiest to connect to the grid,” Jussi explains. “As more wind power is connected to the grid, the assurance of stable, high quality energy takes precedence over energy generation.”
Full-power converters (FPC) already include features such as reactive power generation and low voltage ride-through (LVRT). These inherent benefits help FPCs fulfill the world’s strictest grid code requirements, including the German BDEW 2008. Low flicker, electrical noise emission and total harmonic distortion (THD) also add to the final quality that FPCs feed into the grid.
“When FPCs are the main driver, then it’s simply natural for turbine manufacturers to choose PMGs to create an optimum drive train,” Jussi summarizes.
Fact or fiction? Now with the recent shift in focus from generating more wind power electricity to connecting with stability and quality, it’s fiction to believe that PMGs alone are the driver to the new technology choice of wind turbine manufacturers. Some turbine manufacturers want FPCs to assure grid connectivity and then they complement their selection with PMGs to reach the highest AEP.
This story is featured in Switching on Frequently 04/2012.
Go to newsletter
