New Wind Turbine Pitch System from Moog


At the WINDPOWER 2011 conference, Moog Industrial Group—a division of Moog Inc.—unveiled a new electric pitch system that offers wind turbine operators higher performance, reliability, additional safety, and lower maintenance costs to address key challenges faced by wind turbine manufacturers and operators. The Moog wind turbine pitch system is equipped with Moog’s new AC synchronous electromagnetic brushless servo motor, which meets the requirements of onshore and offshore wind turbines. The pitch systems also include Moog’s pitch servo drive and backup systems.

Pitch control systems are responsible for the precise positioning of blades, which enable wind turbines to operate at optimum speeds to ensure the highest availability and safety. The harsh conditions that turbines operate in require the pitch system and its components to face, among other things, low and unsteady wind speeds and ambient operating temperatures ranging from -30° C up to +50° C (-22 to +122° F).

“Striking a fine balance between parameters like performance, reliability, safety, and costs are key challenges facing wind turbine OEMs and operators,” says Mauro Gnecco, business development manager, wind energy. “When compared with conventional DC pitch systems, the AC brushless technology is designed to be a very high performance system with lower maintenance costs.”

“A key challenge for wind turbine manufacturers is the selection of a motion control supplier who is capable of providing a pitch control system that maximizes reliability and minimizes mechanical complexity,” according to Sal Spada, research director at ARC Advisory Group. “Pitch control systems combined with synchronous servo motors harness advanced technologies that deliver reliable and consistent performance enabling wind turbine manufacturers and operators to maximize productivity and ROI.”

Moog designed its new wind turbine pitch servo motor to withstand extreme temperatures, vibrations, and humidity. When coupled with the associated Moog wind turbine pitch servo drive, the motor has a very high peak power density and also has the capability to be controlled in sensorless mode, which enables the servo drive to control the motor in situations where position information is lost from the servo motor’s encoder or resolver.

Moog built its pitch servo motors to meet the requirements of corrosion class C5M (according to DIN 12944 standards) and with wind-proof connector technology. The motor is suitable for Hot Climate Versions (HCV) as well as Cold Climate Versions (CCV) in both onshore and offshore environments. For more information please visit