A new micro-generating wind turbine for small businesses, farms and local communities
UK company 4Navitas Green Energy Solutions Ltd has successfully developed a vertical axis wind turbine (VAWT) which is set to revolutionise the worldwide onshore wind turbine market, currently dominated by horizontal axis wind turbines (HAWT).
The focus of the design concept was to avoid fatigue, an ongoing issue in HAWTs with wind coming from all directions, creating bearing and gearbox stress due to yaw/pitch requirements, ultimately leading to failure or the need for extensive maintenance prior to the 20-year recommended lifespan.
With the VAWT, there is no need for a blade pitch control system, and with power, electronics, motor and gearbox at ground level for easy maintenance, wear is considerably reduced and performance improved well beyond the 20-year predicted lifespan.
Fully integrated Siemens drive system
4Navitas worked with HMK & Siemens over a period of 18 months to refine the design and engineering of the wind turbine, and from this long-term collaboration a robust and efficient turbine with excellent power output has been developed. Drive, motor, coupling and gearbox use the Siemens integrated drive system (IDS) for best performance and extended life. Output is now rated at up to 75kW with plans for a 1-megawatt version already in the pipeline.
The 4Navitas VAWT houses a Siemens FZG helical bevel gear unit at its base, and the IE3 rated motor is close coupled with the gearbox. The shaft is supported by bearings down the mast so gearbox load and fatigue transfer is significantly reduced.
The power from the wind is controlled by a Siemens S7-1200 PLC and a Siemens Sinamics S120 system. The S120 harnesses the wind power, even in turbulent conditions, and by using Active Front End (AFE) technology connected and synchronised to the supply, transmits power back to the 415V 3-phase grid.