– 15 May 2014 –
During the first project months the technical specifications for the WINDUR turbine were set. Not all the specifications have been determined as some of them will be decided after a trial-and-error phase.
The following specifications are now final:
– Nominal power = 4 kW
– Maximum rotor speed = 250-350 rpm
– Rotor swept area = 10m²
– 3-bladed Darrieus type rotor
– Target cut-in wind speed < 3 m/s
The nominal power was set at 4 kW as one of the main purposes of the WINDUR turbine is roof top installation. For a 5 kW turbine a rotor swept area of around 15m² is necessary, which is a very high dimension for a wind turbine to be mounted on top of a building. Apart from that another very important aspect that should be considered when determining nominal power is the weight that building roof tops can withstand. This is generally set at 100kg/m².
When designing the rotor the general specifications will be taken into consideration, but also the structural behavior, weight and manufacturing cost. The goal is to optimize the aerodynamic performance by implementing different iterative design loops.
The turbine will also include a variable speed control system to maximize the energy yield under rapidly changing wind speeds. Since the purpose of the power electronics is to maximize the energy transfer from the wind turbine rotor to the grid, the selection of commercially available components and the power components design will mainly depend on the rotor design.