Improving the reliability and energy production of large wind turbine with a digital hydrostatic drivetrain

Feng Wang, Jincheng Chen, Bing Xu, Kim A. Stelson

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


Gearbox failure is one of the major factors causing the increased downtime in modern wind turbines. This increases the turbine maintenance cost and therefore the turbine cost of energy. A hydrostatic transmission not only improves the turbine reliability through its “soft” transmission, but also eliminates the use of power converter through its continuous variable transmission function. A hydrostatic wind turbine usually employs a fixed displacement pump to drive a variable displacement motor. The variable displacement motor runs at partial displacement when the wind speed is below the rated wind speed, leading to low drivetrain efficiency. Moreover, large variable displacement motors for large utility wind turbine are not commercially available. Therefore in this paper a digital hydrostatic transmission solution for large utility wind turbine has been proposed. The large variable displacement motor was replaced by combining several fixed displacement motors and a small variable displacement motor with some digital encoding scheme. Two encoding schemes have been proposed for digital hydrostatic transmission. The modeling and design of the digital hydrostatic wind turbine were presented. A hydrostatic wind turbine control based on kw2 control law has been proposed. A dynamic simulation model of the digital hydrostatic wind turbine has been developed. The proposed digital hydrostatic drive solution has been compared with a conventional hydrostatic solution in a commercial 2.5 MW wind turbine. Simulation studies verified the feasibility and the engineering practice of the proposed digital hydrostatic drive solution.

Original languageEnglish (US)
Article number113309
JournalApplied Energy
StatePublished - Oct 1 2019

Bibliographical note

Publisher Copyright:
© 2019


  • Digital hydrostatic drive
  • Hydrostatic transmission
  • Hydrostatic wind turbine
  • Large utility wind turbine


Dive into the research topics of 'Improving the reliability and energy production of large wind turbine with a digital hydrostatic drivetrain'. Together they form a unique fingerprint.

Cite this