Configuration Analysis and Design of a Wind Turbine With Hydrostatic Transmission System

Abstract

This paper presents a methodology for designing and dimensioning of hydrostatic transmission system (HTS) configurations for wind turbines. HTS provides an alternative method to the gearbox in wind power applications. It decouples the turbine and the generator such that the generator can be driven at synchronous speed regardless of wind speed variation. A comparison of different HTS configurations shows that the functionality and performance of the proposed system depends on proper dimensioning of hydraulic components and the circuit configuration. Practical constraints of wind turbine and hydraulic technologies are considered in the design to configure an industrial scale system. The design objectives include obtaining the maximum system efficiency at the rated and high efficiency at partial load. Different hydrostatic systems were designed and simulated to show potentials for improving the overall efficiency of wind power using HTS. It was shown that the larger swept area and moderate speed generator improve efficiency of hydrostatic drivetrain. Optimization of the entire HTSWT can improve output power from a HTSWT to an extent that its annual energy production (AEP) becomes closely equal to AEP of a geared WT.