A simulation BEM data mapping method and system for tandem double-wind-wheel wind turbine

Abstract

The application discloses a BEM data mapping method and system for simulation of a tandem double-wind-wheel wind turbine, and the BEM data mapping method comprises the following steps: obtaining front and rear wind-wheel blade profile data and obtaining an incoming wind speed; taking the incoming wind speed and a real-time wind-wheel rotating speed as indexes, and taking the front and rear wind-wheel blade profile data as a basis to look up a double-wind-wheel BEM wind speed-torque mapping table generated in advance; and outputting front and rear wind-wheel prime mover mechanical torques. The method is used for simulating the output mechanical torques of the front and rear wind-wheel prime movers of the tandem double-wind-wheel wind turbine in the running process of the tandem double-wind-wheel wind turbine under different incoming wind speeds, and is an important technical link for accurate simulation of the tandem double-wind-wheel wind turbine.

Description

Technical Field

[0001] The present invention relates to the field of wind turbine blade design, and in particular to a BEM data mapping method and system for simulating a tandem dual-rotor wind turbine generator set. Background Art

[0002] The calculation model based on blade element momentum theory, consisting of a set of algebraic equations, is widely used in wind turbine blade design. The basic starting point of blade element theory is to divide the rotor blade into numerous microsegments along its span, called blade elements. Assuming that the flow through each blade element is non-interfering, meaning that the blade element can be considered a two-dimensional airfoil, the forces and moments acting on the rotor can be calculated by integrating the forces and moments acting on each blade element along its span.

[0003] In the simulation of typical wind turbines, formulas based on conventional wind turbine mathematical models are often used to calculate the prime mover's mechanical torque for the front and rear rotors based on inflow wind speed data. Currently, no patents exist for using torque mapping based on the BEM method to derive rotor torque.

[0004] For tandem twin-rotor wind turbines, there is no mature solution for obtaining the wind rotor torque using torque mapping based on the BEM method. The BEM data mapping method for tandem twin-rotor wind turbine simulation is currently a blank area.

[0005] Disadvantages of existing technical solutions:

[0006] 1. The calculation method based on the formula of the conventional wind turbine mathematical model is a theoretical calculation. The simulation is quite different from the actual situation, and it cannot adapt to the actual data of different wind turbine blade types.

[0007] 2. Since there is no universal torque output mathematical model for tandem twin-rotor wind turbines, existing technical solutions cannot be applied to tandem twin-rotor wind turbines. Summary of the Invention

[0008] Aiming at the simulation equivalence of a tandem twin-rotor wind turbine, the present invention provides a BEM data mapping method and system for the simulation of a tandem twin-rotor wind turbine. The method is used to simulate the output mechanical torque of the front and rear wind wheel prime movers during the operation of the tandem twin-rotor wind turbine under different inflow wind speeds, and is an important technical link for the accurate simulation of the tandem twin-rotor wind turbine.

[0009] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0010] A BEM data mapping method for simulating a tandem twin-rotor wind turbine generator system includes the following steps:

[0011] Obtain the front and rear wind wheel blade data and the inflow wind speed;

[0012] Using the inflow wind speed and the real-time wind rotor speed as indexes, searching a pre-generated dual-rotor BEM wind speed-torque mapping table based on the front and rear wind rotor blade profile data;

[0013] Output the mechanical torque of the front and rear wind wheel prime movers.

[0014] As a further improvement of the present invention, the method for producing the pre-generated dual-rotor BEM wind speed-torque mapping table comprises the following steps:

[0015] Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds; based on the rear wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the rear wind rotor at different wind speeds;

[0016] At each inflow wind speed, the front wind rotor output mechanical power Pmf and the front wind rotor output mechanical torque Tmf are calculated based on the front wind rotor optimal speed wf and the front wind rotor optimal wind energy utilization coefficient Cpf value; the rear wind rotor output mechanical power Pmb and the rear wind rotor output mechanical torque Tmb are calculated based on the rear wind rotor optimal speed wb and the rear wind rotor optimal wind energy utilization coefficient Cpb value;

[0017] The output mechanical torques of the front and rear wind rotors calculated for each inflow wind speed are combined to generate a dual-rotor BEM wind speed-torque mapping table.

[0018] As a further improvement of the present invention, the front wind wheel output mechanical power Pmf=Pvind×front wind wheel optimal wind energy utilization coefficient Cpf; the front wind wheel output mechanical torque Tmf=Pmf / front wind wheel optimal speed wf.

[0019] As a further improvement of the present invention, the rear wind wheel output mechanical power Pmb=Pvind×rear wind wheel optimal wind energy utilization coefficient Cpb; the rear wind wheel output mechanical torque Tmb=Pmb / rear wind wheel optimal speed wb.

[0020] As a further improvement of the present invention, if the inflow wind speed is not in the horizontal coordinate of the dual-rotor BEM wind speed-torque mapping table, the mechanical torque of the front and rear wind wheel prime movers is output according to the linear interpolation algorithm based on the two adjacent wind speed indexes in the dual-rotor BEM wind speed-torque mapping table.

[0021] A BEM data mapping system for simulating a tandem twin-rotor wind turbine generator system, comprising:

[0022] An acquisition module is used to obtain the front and rear wind wheel blade data and the inflow wind speed;

[0023] A calculation module is configured to use the inflow wind speed and the real-time wind rotor speed as indexes to search a pre-generated dual-rotor BEM wind speed-torque mapping table based on the front and rear wind rotor blade profile data;

[0024] The output module is used to output the mechanical torque of the front and rear wind wheel prime movers.

[0025] Preferably, the method for producing the pre-generated dual-rotor BEM wind speed-torque mapping table in the calculation module includes:

[0026] Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds; based on the rear wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the rear wind rotor at different wind speeds;

[0027] At each inflow wind speed, the front wind rotor output mechanical power Pmf and the front wind rotor output mechanical torque Tmf are calculated based on the front wind rotor optimal speed wf and the front wind rotor optimal wind energy utilization coefficient Cpf value; the rear wind rotor output mechanical power Pmb and the rear wind rotor output mechanical torque Tmb are calculated based on the rear wind rotor optimal speed wb and the rear wind rotor optimal wind energy utilization coefficient Cpb value;

[0028] The output mechanical torques of the front and rear wind rotors calculated for each inflow wind speed are combined to generate a dual-rotor BEM wind speed-torque mapping table.

[0029] Preferably, the calculation module is also used to output the mechanical torque of the front and rear wind wheel prime movers according to the linear interpolation algorithm based on the two adjacent wind speed indexes in the dual wind wheel BEM wind speed-torque mapping table if the inflow wind speed is not in the horizontal coordinate of the dual wind wheel BEM wind speed-torque mapping table.

[0030] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the BEM data mapping method for simulating a tandem twin-rotor wind turbine are implemented.

[0031] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a BEM data mapping method for simulating a tandem twin-rotor wind turbine generator set.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention aims at simulating the equivalence of a tandem twin-rotor wind turbine set. Through a pre-generated twin-rotor BEM wind speed-torque mapping table, it is only necessary to obtain the front and rear rotor blade data and the inflow wind speed. That is, the output mechanical torque of the front and rear rotor prime movers during the operation of the tandem twin-rotor wind turbine set under different inflow wind speeds can be simulated, and the simulation can be performed quickly and realistically, thereby improving the authenticity of the simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings:

[0035] Figure 1 This is a flow chart of a BEM data mapping method for simulating a tandem twin-rotor wind turbine generator system according to a preferred embodiment of the present invention;

[0036] Figure 2 Flowchart of the BEM data mapping method for tandem twin-rotor wind turbine simulation;

[0037] Figure 3 This is a schematic diagram of the BEM data mapping system structure for simulating a tandem twin-rotor wind turbine generator system according to a preferred embodiment of the present invention;

[0038] Figure 4 Schematic diagram of the input and output connections of the BEM data mapping system for tandem twin-rotor wind turbine simulation;

[0039] Figure 5 This is a schematic diagram of the structure of an electronic device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0041] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] Tandem dual-rotor wind turbine: Based on the traditional wind turbine, a rotating wind rotor is added on the opposite side of the back of the wind turbine to absorb the remaining wind energy after the wind passes through the front wind rotor.

[0044] BEM Method: Blade Element (BEM) theory is a mathematical model commonly used in science and industry. It is not only applicable to wind turbine blade design, but also can be used to evaluate wind turbine performance (both during and after design). The BEM method refers to the use of a comprehensive theoretical model to design blades, determine rotor geometry (rotor diameter, aerodynamic airfoil, chord length, pitch angle, and twist angle), estimate blade forces, determine rotor shaft torque and output power, and evaluate rotor performance over a wide wind speed range.

[0045] like Figure 1 As shown, the present invention provides a BEM data mapping method for simulating a tandem twin-rotor wind turbine generator system, comprising the following steps:

[0046] Obtain the front and rear wind wheel blade data and the inflow wind speed;

[0047] Using the inflow wind speed and the real-time wind rotor speed as indexes, searching a pre-generated dual-rotor BEM wind speed-torque mapping table based on the front and rear wind rotor blade profile data;

[0048] Output the mechanical torque of the front and rear wind wheel prime movers.

[0049] The method for producing the pre-generated dual-rotor BEM wind speed-torque mapping table comprises the following steps:

[0050] Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds; based on the rear wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the front wind rotor at different wind speeds;

[0051] At each inflow wind speed, the front wind rotor output mechanical power Pmf and the front wind rotor output mechanical torque Tmf are calculated based on the front wind rotor optimal speed wf and the front wind rotor optimal wind energy utilization coefficient Cpf value; the rear wind rotor output mechanical power Pmb and the rear wind rotor output mechanical torque Tmb are calculated based on the rear wind rotor optimal speed wb and the rear wind rotor optimal wind energy utilization coefficient Cpb value;

[0052] The output mechanical torques of the front and rear wind rotors calculated for each inflow wind speed are combined to generate a dual-rotor BEM wind speed-torque mapping table.

[0053] The present invention aims at simulating the equivalence of a tandem twin-rotor wind turbine set. By using a pre-generated twin-rotor BEM wind speed-torque mapping table, the output mechanical torque of the front and rear wind wheel prime movers of the tandem twin-rotor wind turbine set during operation under different inflow wind speeds is simulated. The simulation can be performed quickly and realistically, thereby improving the authenticity of the simulation.

[0054] like Figure 2 The BEM data mapping method for tandem twin-rotor wind turbine simulation includes the following steps:

[0055] 1. Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds. The specific BEM calculation method does not fall within the scope of this patent and will not be introduced in detail;

[0056] 2. Based on the blade profile data of the rear wind rotor, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the front wind rotor at different wind speeds. The specific BEM calculation method does not fall within the scope of this patent and will not be introduced in detail;

[0057] 3. At each inflow wind speed, the front wind rotor output mechanical power Pmf and the front wind rotor output mechanical torque Tmf are calculated based on the front wind rotor optimal speed wf and Cpf value;

[0058] 4. At each inflow wind speed, the rear wind wheel output mechanical power Pmb and rear wind wheel output mechanical torque Tmb are calculated based on the rear wind wheel optimal speed wb and Cpb value;

[0059] 5. Combine the front and rear rotor output mechanical torques calculated for each inflow wind speed to generate a dual-rotor BEM wind speed-torque mapping table;

[0060] 6. In the dual-rotor simulation system, use the simulation system inflow wind speed vwind as the index to search the dual-rotor BEM wind speed-torque mapping table and output the mechanical torque of the front and rear wind wheel prime movers;

[0061] 7. If vwind is not in the horizontal coordinate of the mapping table, the mechanical torque of the front and rear wind wheel prime movers is output based on the linear interpolation algorithm using the two adjacent wind speed indexes in the mapping table.

[0062] Among them, the front wind wheel output mechanical power Pmf=Pvind×front wind wheel optimal wind energy utilization coefficient Cpf; the front wind wheel output mechanical torque Tmf=Pmf / front wind wheel optimal speed wf.

[0063] The rear wind wheel output mechanical power Pmb=Pvind×rear wind wheel optimal wind energy utilization coefficient Cpb; the rear wind wheel output mechanical torque Tmb=Pmb / rear wind wheel optimal speed wb.

[0064] like Figure 3 As shown, another object of the present invention is to provide a BEM data mapping system for simulating a tandem twin-rotor wind turbine, comprising:

[0065] An acquisition module is used to obtain the front and rear wind wheel blade data and the inflow wind speed;

[0066] A calculation module is configured to use the inflow wind speed and the real-time wind rotor speed as indexes to search a pre-generated dual-rotor BEM wind speed-torque mapping table based on the front and rear wind rotor blade profile data;

[0067] The output module is used to output the mechanical torque of the front and rear wind wheel prime movers.

[0068] like Figure 4 As shown. The BEM data mapping system for the simulation of a tandem twin-rotor wind turbine consists of two inputs and one output. The input is the 1-bit inflow wind speed vwind of the simulation system. The input is the 2-bit front and rear wind turbine blade data. The output is the mechanical torque Tmf and Tmb of the front and rear wind turbine prime movers. The BEM data mapping system for the simulation of a tandem twin-rotor wind turbine is Figure 1 The actual implementation system of the mapping method process.

[0069] The method for producing the pre-generated dual-rotor BEM wind speed-torque mapping table in the calculation module includes:

[0070] Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds; based on the rear wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the front wind rotor at different wind speeds;

[0071] At each incoming wind speed, the front wind wheel output mechanical power Pmf and the front wind wheel output mechanical torque Tmf are calculated according to the front wind wheel optimal rotating speed wf and the front wind wheel optimal wind energy utilization coefficient Cpf value; the rear wind wheel output mechanical power Pmb and the rear wind wheel output mechanical torque Tmb are calculated according to the rear wind wheel optimal rotating speed wb and the rear wind wheel optimal wind energy utilization coefficient Cpb value;

[0072] The front and rear wind wheel output mechanical torques calculated at each incoming wind speed are merged to generate a double wind wheel BEM wind speed-torque mapping table.

[0073] The calculation module is further configured to, if the incoming wind speed is not in the horizontal coordinates of the double wind wheel BEM wind speed-torque mapping table, output the front and rear wind wheel prime mover mechanical torques according to a linear interpolation algorithm based on the two nearest wind speed indexes in the double wind wheel BEM wind speed-torque mapping table.

[0074] As shown in Figure 5 The third object of the present application is to provide an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the BEM data mapping method for simulation of a tandem double wind wheel wind turbine when executing the computer program.

[0075] The BEM data mapping method for simulation of a tandem double wind wheel wind turbine includes the following steps:

[0076] Obtaining front and rear wind wheel airfoil data and an incoming wind speed;

[0077] Using the incoming wind speed and a real-time wind wheel rotating speed as indexes, the double wind wheel BEM wind speed-torque mapping table is searched based on the front and rear wind wheel airfoil data;

[0078] Outputting front and rear wind wheel prime mover mechanical torques.

[0079] The fourth object of the present application is to provide a computer readable storage medium storing a computer program, wherein the computer program implements the steps of the BEM data mapping method for simulation of a tandem double wind wheel wind turbine when executed by a processor.

[0080] The BEM data mapping method for simulation of a tandem double wind wheel wind turbine includes the following steps:

[0081] Obtaining front and rear wind wheel airfoil data and an incoming wind speed;

[0082] Using the incoming wind speed and a real-time wind wheel rotating speed as indexes, the double wind wheel BEM wind speed-torque mapping table is searched based on the front and rear wind wheel airfoil data;

[0083] Output the mechanical torque of the front and rear wind wheel prime movers.

[0084] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0085] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0086] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A BEM data mapping method for simulating a tandem twin-rotor wind turbine generator system, characterized in that: The following steps are involved: Obtain the front and rear wind wheel blade data and the inflow wind speed; Using the inflow wind speed and the real-time wind rotor speed as indexes, searching a pre-generated dual-rotor BEM wind speed-torque mapping table based on the front and rear wind rotor blade profile data; Output the mechanical torque of the front and rear wind wheel prime movers; The method for producing the pre-generated dual-rotor BEM wind speed-torque mapping table comprises the following steps: Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds; based on the rear wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the rear wind rotor at different wind speeds; At each inflow wind speed, the front wind rotor output mechanical power Pmf and the front wind rotor output mechanical torque Tmf are calculated based on the front wind rotor optimal speed wf and the front wind rotor optimal wind energy utilization coefficient Cpf value; the rear wind rotor output mechanical power Pmb and the rear wind rotor output mechanical torque Tmb are calculated based on the rear wind rotor optimal speed wb and the rear wind rotor optimal wind energy utilization coefficient Cpb value; Combine the front and rear rotor output mechanical torques calculated for each inflow wind speed to generate a dual-rotor BEM wind speed-torque mapping table; The front wind wheel output mechanical power Pmf=Pvind×front wind wheel optimal wind energy utilization coefficient Cpf; the front wind wheel output mechanical torque Tmf=Pmf / front wind wheel optimal speed wf; The rear wind wheel output mechanical power Pmb=Pvind×the rear wind wheel optimal wind energy utilization coefficient Cpb; the rear wind wheel output mechanical torque Tmb=Pmb / the rear wind wheel optimal speed wb; If the inflow wind speed is not in the horizontal coordinate of the dual-rotor BEM wind speed-torque mapping table, the mechanical torque of the front and rear wind wheel prime movers is output according to the linear interpolation algorithm based on the two adjacent wind speed indexes in the dual-rotor BEM wind speed-torque mapping table.

2. A BEM data mapping system for simulating a tandem twin-rotor wind turbine, characterized in that: include: An acquisition module is used to obtain the front and rear wind wheel blade data and the inflow wind speed; A calculation module is configured to use the inflow wind speed and the real-time wind rotor speed as indexes to search a pre-generated dual-rotor BEM wind speed-torque mapping table based on the front and rear wind rotor blade profile data; Output module, used to output the mechanical torque of the front and rear wind wheel prime movers; The method for producing the pre-generated dual-rotor BEM wind speed-torque mapping table in the calculation module includes: Based on the front wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpf value of the front wind rotor at different wind speeds; based on the rear wind rotor blade data, the BEM method is used to calculate the optimal wind energy utilization coefficient Cpb value of the rear wind rotor at different wind speeds; At each inflow wind speed, the front wind rotor output mechanical power Pmf and the front wind rotor output mechanical torque Tmf are calculated based on the front wind rotor optimal speed wf and the front wind rotor optimal wind energy utilization coefficient Cpf value; the rear wind rotor output mechanical power Pmb and the rear wind rotor output mechanical torque Tmb are calculated based on the rear wind rotor optimal speed wb and the rear wind rotor optimal wind energy utilization coefficient Cpb value; Combine the front and rear rotor output mechanical torques calculated for each inflow wind speed to generate a dual-rotor BEM wind speed-torque mapping table; The calculation module is also used to output the mechanical torque of the front and rear wind wheel prime movers according to the linear interpolation algorithm based on the two adjacent wind speed indexes in the dual wind wheel BEM wind speed-torque mapping table if the inflow wind speed is not in the horizontal coordinate of the dual wind wheel BEM wind speed-torque mapping table.

3. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the BEM data mapping method for simulating a serial dual-rotor wind turbine set as claimed in claim 1 are implemented.

4. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the computer program implements the steps of the BEM data mapping method for simulating a tandem twin-rotor wind turbine set according to claim 1.

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