The DIRECTWIND turbine feeds generator power into the grid by means of a modern ‘back-to-back’ type full-converter system. This converter contains a number of programmable functions like a capability to limit output during night hours and a noise reduction measure. Built-in grid-fault-ride-through technology is available on demand.

All advanced grid features combined turn the DIRECTWIND into a perfect choice for solitary applications, weak grids, high-turbulence sites, and demanding locations where specific environmental demands have to be met. The combination of advanced control features and proven wind technology makes the DIRECTWIND also a first-class choice with regard to energy yield and overall return on investment.

Direct Drive technology

EWT’s pitch controlled variable speed models wind turbine, combines advanced technology with mechanical simplicity and superior systems reliability. Heart of this proven direct drive turbine is a long-lasting slow rotating EWT-design multi-pole ring generator.

This reliable drive solution with a track record of over 200 operational units worldwide, replaces a complex high-speed geared drive train common in most competitor wind turbines.

A large single main bearing carries both the rotor assembly and generator rotor, and reduces the number of rotating components even further. And the load-optimised ‘monocoque type’ main chassis enables easy service access to essential rotor hub internals like rotor blade pitch drives and battery back-up units.

Light components, high reliability, reduced maintenance and excellent energy yield ensure an optimal return on investment.

We look forward to show you what our DIRECTWIND systems can offer in terms of
minimised Costs of Energy during a twenty-year operational period.

Blade design

The blades were designed by Stevin Laboratories of Delft University in the Netherlands. A 12° twist is built in to the blade to keep the angle of attack constant over the length of the blade. The blades are manufactured using a glass fibre reinforced epoxy.

Directwind Management System

Control System Overview

EWT’s state-of-the-art control system ensures maximum up-time for your turbine by integrating Bachmann Electronic’s M1 PLC running EWT proprietary software and tried and trusted sensing and actuation hardware.

Three PLC units, main controller in the Towerbase, remote IO in the nacelle and pitch controller in the rotor make up the brains of the control system. Fibre optic connection up the tower ensures reliable and immediate response times, while the reliable CANopen bus protocol secures communication between the nacelle and rotor.

Pitch Control and Safety

Currently EWT’s pitch control system uses a VSD-controlled DC motor to swivel each blade independently, controlled by the pitch control PLC. Safety backup is provided by batteries (one per blade providing triple redundancy) which are directly connected to the DC motor terminals in case of VSD or PLC failure or power loss. The turbine will not start up if the safety system is not functioning and during operation the safety system is monitored continuously and automatically tested on a regular basis.

EWT is developing a supercapacitor system to replace the batteries of the safety system, to further improve reliability and longevity of this crucial component, extending its resilience to harsh temperatures and electrical and mechanical loads, and dramatically reducing maintenance.

In conjunction with one of our partners, we have also developed a closed loop AC motor pitch control system which will be installed on our 2MW prototype, affording greater cost-effectiveness in terms of turbine components and maintenance, as well as increased blade controllability. All the aforementioned safety features are still present, or equivalents thereof added to the design, ensuring the same triple redundancy to ensure the safety of man and machine.

Operator Interface: DWMS and DMS 2.0

The Directwind Management System provides monitoring, control and statistical analysis from within the turbine or from the comfort of your office.

DMS 2.0 is a brand new OPC-based HMI (replacing DWMS) operating on a Microsoft Windows platform that facilitates remote and local monitoring, control and statistical analysis to a high level of efficiency, giving operators and engineers the perfect interface with their machines. User access is controlled and logged, and park owners will enjoy unparalleled confidence in the management of their wind parks.

Also in the pipeline is a mobile/PDA version of the software to give instant access to wind parks and turbines from almost anywhere in the world.

EWT products

EWT’s main volume product is the 900 kW series, a pitch controlled variable speed wind turbine that combines continuous market driven innovation with proven state-of-the-art wind technology. From a wind technology track record perspective the 900 kW model builds on more than ten years operational experience with our 750 kW turbine series. This turbine type boasts a track record of over 300 units operating in many different wind climates and regions spread across Europe, Asia and North America.

The medium size product range (600 – 1000 kW) has so far been the key company target market segment. As a new addition to our current product range EWT has launched its new 2.0 MW Direct Drive turbine.