Romax to help design drivetrain

The US Energy Department (DOE) has selected Romax Technology as lead mechanical engineer in a consortium that will develop an innovative wind turbine drivetrain design.

The $3m project is directed by DOE’s National Renewable Energy Laboratory in Golden, Colorado, near Denver.

The project was developed with the brief of studying advanced drivetrain technology that can be scaled for large turbines and ultimately reduce the cost of wind energy.

Romax is contributing its mechanical engineering and wind turbine expertise to a consortium which includes NREL, DNV, DOE's Oak Ridge National Laboratory, GE Wind and Vattenfall Windpower.

The Romax gearbox design will consist of a single, planetary stage that reduces part numbers by eliminating higher speed gear stages, and investigates the use of planet journal bearings for minimizing planet stage size.

The team's concept will scale to ratings as high as 10MW whilst maintaining the lowest possible costs.

Romax's involvement in the project started in 2011 when it was selected to be part of an NREL team that competed against six other groups to conduct a study of advanced drivetrain technologies. The team was one of only two awarded funding for a follow-on phase to build a prototype and demonstrate commercialisation of the technology.

The drivetrain will be tested in the NREL's 2.5MW dynamometer and will utilise the NREL's newly commissioned Controllable Grid Interface (CGI) to replicate the loads wind turbines undergo in the field," says Christopher Halse, Romax engineering manager in the US.

"There have been reliability concerns with traditional high speed gearbox designs resulting from the impacts of large and unpredictable loads imparted on the gears and bearings.  These types of loads are caused both by the wind acting on the rotor and by utility faults to the wind turbine gearbox through the generator,” according to NREL.

“It is these factors we are striving to address and through the consortium we have every confidence that all the parties involved will play a significant role in improving the drivetrain's overall reliability," it adds.