Motion Technologies CRADA CRD-03-130: Assessing the Potential of a Mechanical Continuously Variable Transmission

This report summarizes the results of a cooperative research and development agreement (CRADA) between the National Renewable Energy Laboratory (NREL) and Motion Technologies LLC. The purpose of the CRADA is to assess the usefulness of a continuously variable transmission (CVT) for wind turbine applications. The CVT considered is capable of rapid ratio changes and may be directly applicable tovariable speed wind turbine designs. This approach potentially offers a less expensive mechanical alternative to the use of power electronics (PE) currently used in large and small machines for variable speed operation. According to Motion Technologies, the CVT is the first continuously variable transmission that is scalable to the torque capacities required in large wind turbine applications.The CVT technology was examined for potential economic and performance benefits when integrated into conventional wind turbine designs. This report is the first step in assessing the practicality of using CVT technology in variable speed wind turbines.