A Comparative Performance Analysis of Counter-Rotating Dual-Rotor Wind Turbines with Speed-Adding Increasers

Abstract

Increasing the efficiency of wind power conversion into electricity poses major challenges to researchers and developers of wind turbines, who are striving for new solutions that can ensure better use of local wind potential in terms of both feasibility and affordability. The paper proposes a novel concept of wind systems with counter-rotating wind rotors that can integrate either conventional or counter-rotating electric generators, by means of the same differential planetary speed increaser, aiming at providing a comparative analysis of the energy performance of counter-rotating wind turbines with counter-rotating vs. conventional electric generators. To this end, a generalized analytical model for angular speeds and torques has been developed, which can be customized for both system configurations. Three numerical simulation scenarios have been contrasted: (a) a scenario with identical wind rotors in both systems, (b) a scenario with the secondary wind rotors being identical in the two applications, but different from the primary rotors, and (c) a scenario with different secondary rotors in the two wind turbines. The results have shown that the wind systems with counter-rotating generator are more efficient and have a higher amplification ratio, compared to systems with conventional generators. In addition, the analyzed wind system with a counter-rotating generator displays better energy performance with low values for output power and ratio of input speeds, whereas the wind turbine with a conventional generator proves to be more efficient in the high-value range of the above-mentioned parameters.

Study on aerodynamic performance of mine air duct horizontal axis wind turbine based on breeze power generation

“…The aerodynamic characteristics on ducted wind turbines with different airfoils are selected and analyzed to verify | 13 the reliability of airfoil selection in the design stage. In this paper, three airfoils BW3, SG6043, A18 with similar airfoil structure to NACA5505 are selected from the "low speed airfoil data summary" to design the airfoil of ducted wind turbine, select the air duct with the same structure, and design and optimize the optimal angle of attack, chord length and other parameters of the airfoil.…”

“…The results show that in the urban environment, compared with the isolated VAWT under low wind speed, the dual VAWT configuration has less effect on the power output of VAWT, but this effect improves slightly with the increase of rotor robustness. Saulescu et al 13 presented a new concept of wind power system. The wind power system has a reverse rotating wind rotor, which can integrate traditional or reverse rotating generators through the same differential planetary speed increaser.…”

Synergetic-PI controller based on genetic algorithm for DPC-PWM strategy of a multi-rotor wind power system

“…These types can be divided into two types: single-rotor WEs [6][7][8] and multi-rotor WEs [9,10]. Whereas the multi-rotor WE is a development of the single-rotor WE in order to increase the value of torque and mechanical energy required to rotate the generator [11]. In addition, the use of multi-rotor WEs leads to a reduction in the area of wind farms and overcomes the winds generated by turbines in wind farms [12].…”

“…253 254 where, S(t) is the surface (S=X*-X).The PI controller can be expressed by the transformation function represented in equation(11).…”

Dynamic Analysis of a Single-Rotor Wind Turbine with Counter-Rotating Electric Generator under Variable Wind Speed

“…Aiming to improve the performance of the electric generators for wind turbines, a counter-rotating generator with permanent magnets for built environment applications is proposed and analysed in [34][35][36]; the counter-rotating generator is proved to have a higher efficiency than the conventional one, with a low starting torque, it is compact and scalable.…”