Variable speed drives promote wind power in urban areas

Paul Boughton
ABB has helped wind power generation experts quietrevolution ltd to develop an innovative wind turbine that promises to capture wind power in areas never before exploited.

Architects, developers and local councils are already showing strong interest in the company’s QR5, a vertical axis wind turbine designed to operate in urban areas, where wind speeds are lower and wind directions change frequently. Its helical design ensures it is robust and able to deal with even turbulent winds. It also eliminates virtually all noise and vibration.

At five metres high and three metres in diameter, the turbine is compact and easy to integrate and with just one moving part, maintenance can be limited to an annual inspection. It is designed for mounting on buildings to generate some of the power load and reduce consumption from the grid.

The wind turbine turns an ABB permanent magnet motor which is linked to an ABB industrial drive acting in regenerative mode to provide the energy conversion and regenerate power back into the grid.

Permanent magnet motors are synchronous machines, designed to drive low speed applications directly, without a gearbox. The motors are designed exclusively for frequency converter supply.  ABB industrial drives are available with permanent magnet motor software to integrate with these motors.

The ABB industrial drive offers a number of benefits to the QR5, including the ability to motor to correct speeds to enhance wind turbine efficiencies very quickly, for example, during wind gusts.

Richard Cochrane, quietrevolution’s founder and chief technical officer, says: “The sensorless control of the permanent magnet generators is a key benefit to the turbine application because of its simplicity and low cost. The drive allows us to switch seamlessly from regeneration to drawing power, as well as giving accurate speed control. This produces the maximum amount of energy from gusty and turbulent winds which are prevalent in urban environments.”

The ABB industrial drives used in the application feature direct torque control (DTC) technology. Says Cochrane: “DTC is crucial in the operation of the turbine as it allows us to effectively vary the rotor speed to optimise performance at any given wind speed.”

Meeting the requirements for connection to the grid, the drive also comes as a complete package with everything required for the application already installed on the drive, including an active supply unit, LCL line filter and charging circuitry. Cochrane adds: “Another useful feature of the ABB drive is the simple communications protocols, which are a cost-effective way to control and report on the performance of the system via our web interface.”

For more information, visit www.abb.com