Design and simulation of a novel continuously variable-speed drivetrain for wind turbine

This paper presents a novel hydrodynamic pressure transmission (HPT) for continuously variable drive train in wind turbine applications. The HPT mainly comprises of the continuous velocity regulator (CVR), the gear speed-increasing mechanism and the electro-hydraulic system. By controlling the CVR in HPT, the wind turbine can easily capture the maximum wind power while keeping the output power frequency constant. The key components of HPT are modeled and the control strategy of variable speed constant frequency control achieved by the HPT is proposed in the paper. The control performances of HPT are then verified and confirmed in a simulation set-up of a 25kW full-scaled wind turbine. Moreover, the HPT has high control reliability and precision, relatively high transmission efficiency, compact structure, and may be especially suitable for megawatt-scale wind turbine applications.