Points of difference
The Windflow 500 wind turbine is a unique design for the next generation of wind turbine. Four points of difference compared to other wind turbines, especially mulit-MW three-bladed turbines: two-bladed pitch teetering, torque limiting gearbox, 500 kW and synchronous generator.
Two-bladed pitch teetering:
The Windflow two-bladed design uniquely allows the turbine blades to teeter on a hinge. This teetering motion is linked to an asymmetric pitching mechanism of the turbine blades. Uneven wind gusts are passively absorbed thus reducing the fatigue loads throughout the turbine. This results in reductions in turbine weight and cost and an increase in turbine reliability.
Torque limiting gearbox:
With the aid of active pitch control, the turbine blades and hub deliver the gearbox with near-constant speed of rotation, via the low speed shaft. The high speed shaft from the gearbox driving the synchronised synchronous generator requires a constant speed of rotation. So, the small variations in hub speed (caused by potentially damaging wind gusts) are absorbed by a hydraulic pump on a second output from the gearbox. The torque limiting gearbox is patented in several countries.
500 kW:
The 500 kW turbine is a direct competitor to 3-bladed multi-mega watt turbines. On a per megawatt installed basis, the smaller, 500 kW turbine allows for easier transportation, more straight-forward installation and reduced environmental and visual impact. These advantages are accentuated in typical New Zealand conditions where the wind resource is extreme, access is often limited and sites can be ecologically sensitive.
Synchronous generator:
Due to the constant input from the Torque Limiting Gearbox, the Windflow turbine is able to utilise a synchronous generator, synchronised directly with the grid without the aid of costly and unreliable power electronics. As well as reducing costs and increasing reliability, this feature allows for easier connection to the grid.
