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Innovation application: Method and Device for Control of Operation of a Wind Energy Installation

Title Method and Device for Control of Operation of a Wind Energy Installation
Abstract

A new method and a device are developed for wind energy extraction. The device consists of a central rotor and several plane blades. The blades are fastened to the rotor and may change the orientation of their working surfaces relative to the direction of incoming wind flow. Each blade is fastened to the rotor with a cylindrical axial hinge, which a longitudinal axis is parallel to the rotor longitudinal axis. The axes of the blades have kinematic connection with the central rotor; therefore the blades rotate as the central rotor rotates about its axis. Optimal angular rotation frequency ratio between the rotor and any blade is equal to 2. The better efficiency of wind energy transformation is the main advantage of the proposed method.

Keywords Air flow, rotor, blade, blade orientation, wind energy installation
Authors Jānis Vība
Vitālijs Beresņevičs
Staņislavs Noskovs
Mārtiņš Irbe
Department (15300) Mehānikas institūts
Statistical Classification of Economic Activities, NACE 2 Electricity, gas, steam and air conditioning suppl
Description of the technology

The wind energy device is constructed by mounting of the rotor (1) athwart to the direction of the air flow V (Fig. 1), by fastening of at least one plane blade (2) to the rotor (1) and by changing of orientation of the blade working surface relative to air flow V during rotation of the rotor (1). During rotation of the rotor (1), each blade is turned on the angle α about the axis O2 parallel to the rotor longitudinal axis O1.

Fig. 1. Operation principle of the wind energy installation, where
1 – a rotor, 2 – a blade; O1 – an axis of the rotor, O2 – a rotation axis of the blade, V – velocity of a wind flow, R – resulting aerodynamic force of the wind flow, M – a torsional moment relative to the axis O1, φ – a turning angle of the rotor radius O1O2 relative to the direction of the wind flow, α – a turning angle of the blade working surface.

The angle α is considered as an optimal, if the resulting aerodynamic force R gives the maximal torsional moment M about the longitudinal axis O1 of the rotor (1), therefore the turning angle α of the blade should be calculated by the equation α = π/4 + 0.5φ, where φ is the turning angle of the rotor radius O1O2 relative to opposite direction of the incoming wind flow. In starting position (under the φ = 0) the blade (2) must be mounted under the angle α = π/4 relative to the direction of the air flow.

 

Fig. 2. The kinematic diagram of the device, where
1 – a rotor, 2 – a blade, 3 –belt transmission, 4 and 5 – pulleys, 6 – a tail.

The flat blade (2) is hinged to the rotor (1). Besides, the longitudinal axes O1 and O2 of the rotor and the blade are mutually parallel and kinematically connected each other with the belt transmission (3). The belt pulley (4) is attached to the blade (2), but the pulley (5) – to the rotor (1). The angular rotation frequency ratio between the rotor (1) and the blade (2) is 2. In this case the blade (2) makes one revolution, but the rotor (1) makes two whole revolutions, thus equation α = π/4 + 0.5φ is fulfilled.

The proposed device has the tail (6) fastened to the pulley (5) to follow changes of the air flow direction, The change of air flow direction causes turning of the tail (6) till it stands parallel to the air flow. The pulley (5) and the rotor (1) are also turned simultaneously, consequently the blade (2) takes the optimal orientation to the air flow in accordance with the equation α = π/4 + 0.5φ.

Applications This method can be used in design, research and manufacturing enterprises that are engaged in development, production and modernization of wind energy installation. The method allows to increase the efficiency of wind energy transformation and to raise the efficiency factor of a wind energy installation.
Advantages

The proposed method and the device for control of operation of a wind energy installation allows

  • to increase the efficiency of wind energy transformation and to raise the efficiency factor of the wind energy installation;
  • to simplify the practical use of the wind energy installation due to self-orientation property that allows to follow any changes of the wind flow direction.

The proposed method and the device can be also used for energy extraction from water flow (e.g., in the river with fast stream).

Technology Readiness Level Experimental proof of concept
Partnership offer • Commercial contracts for design, manufacturing and installation of wind energy equipment. • Technology transfer.
Number
  • 15038
Publikācijas
ID 58
Contact information email: santa.puskarjova@rtu.lv and ilmars.viksne@rtu.lv; phone number: +371 29373757 un +371 29187403