Low Wind Speed Technology Phase I: Advanced Independent Pitch Control; Advanced Energy System, Inc.

In multi-MW (1MW and up) wind generation systems a variable speed - variable pitch (VS-VP) control technology is usually adopted to improve speed and torque characteristics and to obtain the optimal energy, which means to obtain the maximum power at low wind speed and the rated power at high wind speed. The power generated by an individual blade of the wind turbine changes considerably during rotation due for the change of wind speed in vertical direction, which decreases the angles of attack in the low blade positions and which leads to a reducing the generated energy. In the paper basing on BEM theory modification for none-homogenously fluid field and an optimization procedure is obtained an individual variable pitch control law as function of wind speed values and blades positions.

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Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.569-570.668 ◽

2013 ◽

Vol 569-570 ◽

pp. 668-675 ◽

Cited By ~ 2

Author(s):

P.D. Chougule ◽

S.R.K. Nielsen ◽

Biswajit Basu

Keyword(s):

Wind Speed ◽

Wind Turbines ◽

Pitch Angle ◽

Vertical Axis ◽

Power Coefficient ◽

Vertical Axis Wind Turbine ◽

Stream Tube ◽

Pitch Control ◽

Low Wind Speed ◽

Blade Pitch Angle

As Development of smallvertical axis wind turbines (VAWT) for urban use is becoming an interestingtopic both within industry and academia. However, there are few new designs ofvertical axis turbines which are customized for building integration. These aregetting importance because they operate at low rotational speed producing veryless noise during operation, although these are less efficient than HorizontalAxis Wind Turbines (HAWT). The efficiency of a VAWT has been significantlyimproved by H-Darrieus VAWT design based on double airfoil technology asdemonstrated by the authors in a previous publication. Further, it is well knowthat the variation of the blade pitch angle during the rotation improves thepower efficiency. A blade pitch variation is implemented by active blade pitchcontrol, which operates as per wind speed and position of the blade withrespect to the rotor. A double multiple stream tube method is used to determinethe performance of the H-Darrieus VAWT. The power coefficient is compared withthat of a fixed pitch and a variable pitch double airfoil blade VAWT. It isdemonstrated that an improvement in power coefficient by 20% is achieved andthe turbine could start at low wind speed

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Performance assessment of a balloon assisted micro airborne wind turbine system

Energy Harvesting and Systems ◽

10.1515/ehs-2021-0018 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Naveen Prakash Noronha ◽

Krishna Munishamaih

Keyword(s):

Wind Speed ◽

Wind Energy ◽

Wind Turbine ◽

Power Output ◽

Cost Effective ◽

Energy System ◽

Maximum Power ◽

Power Coefficient ◽

Average Wind Speed ◽

Low Wind Speed

Abstract This study intends to examine the performance of a balloon-assisted micro airborne wind turbine in a low wind speed location. The influence of the balloon separation gap on the airborne wind energy system (AWES) performance is also explored. A micro-AWES with a diameter of 3 m and a power output of 1 kW was fabricated and tested at 50, 100, 150, 200, and 250 m. Further, the optimum separation spacing of 13 m was maintained between the balloon and the ducted turbine to reduce balloon turbulence on the turbine. The airborne wind turbine achieved a maximum power output of 250 W at 250 m height while the average wind speed remained 6 m/s. The maximum power coefficient obtained was 0.25 while annual energy production (AEP) remained 1200 kWh. The low power coefficient is credited to the turbulence and drifting in the airborne system and the drag caused by the airborne structure. While a cost-effective commercial model of micro AWES is still being developed, the present work attempts to harvest wind energy at high elevations in low wind speed areas.

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