Apparatus and method for reducing asymmetric rotor loads in wind turbines during shutdown

US8240990B2 · kind B2 · utility

Assignee

• General Electric Company · US

Inventors

• Leonardo Cesar Kammer · Niskayuna, US
• Hubert Oing · Berlin, DE

Key dates

• Filing date: Dec 6, 2007
• Grant date: Aug 14, 2012
• Expiry date: Dec 27, 2031

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/72
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

An apparatus and method for reducing asymmetric rotor load in a wind turbine includes calculating a time delay for pitching each blade toward feather upon initiation of a shutdown condition. The blades with the larger blade angle begin moving toward feather with an initial pitch rate, while the blade with the smallest blade angle begins moving toward feather with a final pitch rate. Once all the blades have reached approximately an identical blade angle, the blades move simultaneously together to feather at the final pitch rate. By introducing the time delay for pitching the blades having higher blade angles at the final pitch rate, a simple, time-based correction of initial conditions during shutdown reduces the extreme loads on turbine components.