The Windrive project

The Windrive project aims to further develop a Brushless Doubly-Fed Induction Generator (Brushless DFIG) technology for widespread implementation in wind power generation, moving it from being a promising and proven concept, demonstrated on small scales, to an optimized industrial-scale machine for multi-megawatt wind turbine applications. This will have a range of impacts – growth in sales and jobs for the SMEs collaborating in the project, knock-on benefits through the supply chain and substantial environmental and social benefits through a more cost-effective and reliable wind power sector.


The wind industry is growing rapidly. In 2009, the EU adopted a wide-ranging package on climate change with a target for a 20% in emissions of Green House Gases by 2020, compared with 1990 levels, a 20% increase in the share of renewables in the energy mix, and a 20% cut in energy consumption. To achieve this, there will be a significant dependence on the generation of energy using wind turbines and, accordingly, wind turbines are increasingly being deployed in large numbers.


However, the reliability and cost-effectiveness of wind turbines still need major improvement to make wind power competitive with conventional power plants. This is particularly important for the growth of offshore wind power generation.


The proposed medium-speed drivetrain incorporates the following components:

  • Medium-speed Brushless DFIG, excluding brush-gear and slip-rings, known to be the highest failure rate components in the generator;
  • Partially (typically a third) rated converter;
  • Two-stage gearbox, excluding the third high-speed stage, known to be the highest failure rate part of the gearbox.

A recent study performed by an independent wind energy consultant shows that the whole balance of life saving as percentage of drivetrain (i.e. generator, converter and gearbox) capital costs can be more than 83%.


The technology is proven in concept on small scales, including a 20 kW prototype wind turbine and most recently, a 250 kW prototype generator on test bed. However, there is a lack of an industrial size machine to prove the technology on real size. Further, engaging with the market is difficult without a real size prototype.


20 kW wind turbine fitted with Brushless DFIG generator
250 kW Brushless DFIG on test

This project will study several aspects of the Brushless DFIG including its design, operation, control and grid connection with an aim to optimize and improve its performance for multi-MW wind turbines. Further, its integration into a wind turbine drivetrain and optimization on a system-level will be carried out. A 3 MW medium-speed Brushless DFIG drivetrain system will be designed and its design, modelling and analysis will be documented in a comprehensive report which can be used by the SME partners during the exploitation phase which will follow the completion of the project.


Brushless DFIG design procedure

The project has nine distinct objectives:


  1. Achieve an overall optimization of the Brushless DFIG design with respect to its manufacturing costs, size, weight and performance.
  2. Achieve optimized control and operation of the Brushless DFIG within a wind turbine.
  3. Establish a grid-friendly system design compatible with recent grid codes of EU countries.
  4. Establish industrial low-cost, reliable mechanical and electrical integration of the Brushless DFIG within a wind turbine with improved components.
  5. Establish industrialized design, construction and operation of the Brushless DFIG drivetrain.
  6. Achieve a quantified assessment of reliability and economics of the Brushless DFIG drivetrain.
  7. Establish a complete design of a 3 MW medium-speed Brushless DFIG drivetrain, ready to be built and tested during the follow-on exploitation phase.
  8. Establish a portfolio of IP in the form of patents and knowhow related to the design and operation of the Brushless DFIG drivetrain, to be exploited by the SME partners.
  9. Disseminate the project’s finding across the wind generation sector in the EU in order to facilitate the wider societal impacts offered by this technology.

Simulations of drivetrain dynamic response

    Simulation of 3-stage gearbox and conventional DFIG

Simulation of 3-stage gearbox and conventional DFIG

    Simulation of 2-stage gearbox and Brushless DFIG

Simulation of 2-stage gearbox and Brushless DFIG