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EP-4735756-A1 - DYNAMIC TORQUE BALANCING MECHANISM IN COUNTER-ROTATING DUAL-ROTOR WIND TURBINES

EP4735756A1EP 4735756 A1EP4735756 A1EP 4735756A1EP-4735756-A1

Abstract

The invention is a blade control and torque balancing mechanism (100) developed for use in dual-rotor wind turbines, characterized by a generator (101) with a rotor and stator connected to two separate shafts, allowing them to rotate in opposite directions. The generator (101) includes two covers and an outer shell with bearing housings and circlip slots. It also features a servomotor (105) linked to a lead screw (108) to adjust angles based on active torque measurement and a decision mechanism; a lead screw (108) that moves forward and backward through the servomotor (105); a torque meter (106) connected to the shafts exiting from the generator (101) rotor and stator to measure the torque generated by the front and rear turbine blades (114); a connection arm (110) that moves along the lead screw (108), allowing the shaft (117) to rotate with the turbine blades (114); an elliptical triangular connection apparatus (111) with bearing and circlip holes for mounting the shaft (117) and servomotor (105), designed to rotate synchronously with the turbine blades (114) and to adjust blade angles by moving with the connection arm (110) back and forth; and a blade connection apparatus (118) positioned on the shaft (117) to adjusting the desired angle actively changing the angle of the turbine blades (114).

Inventors

  • BOLAT, Fevzi Çakmak
  • ÖZBEK, Kadir
  • GEL , Kadir
  • ERTÜRK, ERCAN
  • S VR O LU, Selim

Assignees

  • Kocaeli universitesi
  • Piri Reis Universitesi
  • Abant Izzet Baysal Universitesi Rektorlugu

Dates

Publication Date
20260506
Application Date
20241016

Claims (10)

  1. 1. A blade control and torque balancing mechanism (100) developed for use in dualrotor wind turbines, characterized by comprising; a generator (101) consisting of two covers and an outer shell, containing bearing housings and circlip slots inside, allowing the rotor and stator connected to two different shafts to rotate in opposite directions; - a servomotor (105) connected to a lead screw (108) for changing angles based on active torque measurement and decision mechanism; - the lead screw (108) moved forward and backward by the servomotor (105); - a torque meter (106) connected to the shafts exiting the generator (101 ) rotor and stator for measuring the torque from the front and rear turbine blades (114); - a connection arm (110) that moves along the lead screw (108), allowing a shaft (117) to rotate with the turbine blades (114); - a triangular connection apparatus (111) that elliptical edges on which the connection arms (110) are connected, containing bearing and circlip holes for mounting the shaft (117) and servomotor (105) inside, enabling synchronous rotation with the turbine blades (114) and moving with the forward and backward movement of the connection arm (110) to adjust the angles of the turbine blades (114); - a blade movement connection apparatus (118) positioned on the shaft (117) for adjusting the desired angle by actively changing the angle of the turbine blades (114).
  2. 2. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a slip ring (102) connected to the cables exiting from the generator (101) and movement.
  3. 3. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a generator connection supports (116) for mounting and securing the generator (101) on the base plate.
  4. 4. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a coupling (104) connected on one side to the torque meter (106) and on the other to the shaft (117) from the generator (101 ) rotor and stator.
  5. 5. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; an adjustable torque meter connection apparatus (115) for securing the torque meters (106).
  6. 6. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a blade connection part (113) positioned at the end of the shaft (117) to allowing movement of the turbine blades (114), on which bearing holes for the shafts (117) and holes for securing the shaft (117).
  7. 7. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a bearing (103) that connects the turbine blades (114) to the blade connection part (113).
  8. 8. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a fixed bearing (107) for securing the lead screw (108) to the base plate.
  9. 9. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a lead screw connection apparatus (109) for transmitting the movement of the lead screw (108) to the turbine blades (114).
  10. 10. The blade control and torque balancing mechanism (100) according to Claim 1 , characterized by comprising; a blade control apparatus (112) connected to the triangular connection part (111).

Description

DYNAMIC TORQUE BALANCING MECHANISM IN COUNTER-ROTATING DUAL-ROTOR WIND TURBINES Technical Field The invention relates to a blade control and torque balancing mechanism that includes an algorithm capable of minimizing the torque difference generated by the front and rear rotors by instantaneously measuring the torque values produced by the generator rotor and stator through an active control method. State of the Art A counter-rotating dual-rotor wind turbine is designed to convert wind energy into electrical energy more efficiently. In this turbine, the two rotors rotate in opposite directions, which increases aerodynamic efficiency and enables the turbine to perform optimally across a wider range of wind speeds. This counter-rotational movement allows the rotors to capture wind flow more effectively, resulting in higher energy production efficiency. Compared to traditional single-rotor turbines, this design generates less mechanical stress and vibration, thereby reducing maintenance costs and extending the turbine's lifespan. This technology is particularly preferred in projects aiming to maximize energy yield from wind power. Studies in the literature indicate that counter-rotating dual-rotor wind turbines are more efficient than both single-rotor wind turbines and dual-rotor wind turbines with rotors rotating in the same direction. There are various methods for connecting the rotors to the generator in a counterrotating dual-rotor wind turbine. One such method involves combining the motion of the two counter-rotating rotors using a planetary gear, which is then connected to the generator’s shaft via a single shaft. In this way, the planetary gear makes it possible to combine the movement of both rotors. However, in this design, the stator remains stationary while the rotor rotates. The main disadvantage of this method is the mechanical losses that occur within the gearbox, which diminish the advantages inherent to dual-rotor wind turbines. In single-rotor wind turbines, the stator of the generator is fixed, and the rotor of the wind turbine is connected to the generator’s rotor. The electromechanical force generated within the generator is resisted by the body of the wind turbine, as the stator is fixed to the turbine body. In dual-rotor wind turbines, the front rotor captures part of the energy from the wind, thereby decreasing the wind speed that reaches the rear rotor. Consequently, the rear rotor receives a reduced wind speed with partially depleted energy. When connected to a load, the electromechanical force generated within the generator is resisted by the rear rotor. If the rear rotor cannot produce sufficient aerodynamic torque, this electromechanical force forces the rear rotor to come to a halt. When the rear rotor stops, the system essentially functions as a single-rotor turbine, negating the benefits of a dual-rotor design. In small wind turbines, the blade pitch angles are generally fixed, meaning that the blades are attached to the rotor without any mechanism to alter the blade angles. In studies using a similar design, it has been observed that the rear rotor stops at certain wind speeds, reducing the dual-rotor turbine to a single-rotor operation and thus rendering it ineffective. In the literature, attempts have been made to create a stable system by varying parameters such as blade profiles, blade pitch angles, and chord lengths on both the front and rear rotors. However, in dual-rotor systems with fixed blade angles, it has not been possible for the blades to continue rotating at variable speeds. Similar issues have been encountered in different designs developed by researchers, where the rear rotor was observed to stop at certain wind speeds and blade angles. Many studies have implemented gear systems, which not only increase noise levels but also reduce the efficiency of the wind turbine. The rotor and stator of the wind turbine are attached to two different shafts: one shaft is connected to the front blade group, and the other to the rear blade group. The primary challenge in dual-rotor wind turbines lies in ensuring continuous operation at varying wind speeds. Some systems operate by manually adjusting the blade angles of the front and rear blades for a fixed wind speed. However, in variable wind speeds, the system must be completely stopped, the blade angles readjusted, and then restarted, which renders the practical application of dual-rotor wind turbines infeasible. In conclusion, the necessity of a dynamic torque balancing mechanism in counter-rotating dualrotor wind turbines has become evident, as it addresses the disadvantages present in the existing technology. The inadequacy of current solutions has made advancements in this technical field essential. Summary of the Invention The present invention relates to a blade control and torque balancing mechanism that, by employing an active control method, includes an algorithm capable of minimizing the torque difference generate