A distributed electric / generation integrated propulsion system based on shaftless rim magnetic suspension fan

Abstract

The application belongs to the field of aviation electric propulsion technology, and is an electric motor / generator integrated distributed propulsion system based on a shaftless rim magnetic suspension fan, which comprises a shaftless rim magnetic suspension fan (1), a turbo-generator (2), an integrated controller (3), a bidirectional inverter (4), a battery (5), and an airborne electrical equipment (6); the turbo-generator (2) and the battery (5) drive the distributed shaftless rim magnetic suspension fan (1) through the integrated controller (3) to provide thrust for the aircraft; the shaftless rim magnetic suspension fan (1) is compatible with two working modes of propulsion and power generation and can be converted to each other, the mechanical bearing is replaced by a magnetic suspension bearing, a ring rotor (8) configuration is adopted, the central hub is cancelled, and a permanent magnet synchronous motor and an electromagnetic bearing are compactly integrated; when the aircraft is cruising at high altitude, part of the distributed shaftless rim magnetic suspension fan (1) is adjusted to a high-altitude power generation mode through bidirectional flow airfoils (10), the maximum power point tracking algorithm in the integrated controller (3) is used to obtain the optimal wind energy utilization coefficient, and the maximum output power is charged to the battery (5). The electric motor / generator integrated distributed propulsion technical scheme based on the shaftless rim magnetic suspension fan will help to improve the aerodynamic characteristics of the aircraft, realize the multifunctional integration, integration and energy efficient utilization of the distributed electric propeller, and thus improve the endurance and multi-task adaptability of the aircraft.

Description

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[0001] The present application belongs to the field of aviation electric propulsion, more particularly, it relates to a distributed electric motor / generator integrated propulsion system based on a shaftless rim magnetic suspension fan. BACKGROUND

[0002] The development trend of energy saving, emission reduction, low carbon and environmental protection in the aviation industry is an important direction of future aviation power revolution, and distributed propulsion and energy recovery are important technical paths. Distributed propulsion can increase the equivalent bypass ratio, and the flexible propeller arrangement mode brought by it takes into account the vertical take-off and landing capability, further improving the take-off and landing performance of the aircraft. The successful application of energy recovery technology in electric vehicles proves the feasibility of further reducing carbon emissions. When the aircraft is flying in the high altitude, the huge wind energy in the high altitude provides the condition for realizing energy recovery.

[0003] In recent years, the gradually researched shaftless rim electric motor driving configuration provides a new idea for the future development of aviation electric propulsion system. The shaftless rim driving propulsion system integrates the propulsion device and the driving motor, compared with the traditional motor, shafting and propulsion device structure, not only cancels the traditional through-cabin propulsion shafting and sealing system, but also greatly reduces the transmission mechanism, thereby improving the efficiency and space utilization of the propulsion system.

[0004] Under the condition of equivalent propulsion power, increasing the speed of the motor can effectively reduce the weight of the motor. However, mechanical bearings generate a lot of heat at high speed, which not only reduces the service life of the motor, but also produces a lot of noise. Magnetic suspension bearing makes the motor rotor and stator have no mechanical contact, thereby avoiding severe mechanical wear at high speed. Therefore, magnetic suspension bearing is suitable for high-speed working conditions without lubrication, pollution, long service life and more than 10,000 revolutions.

[0005] Wind energy is called green energy, and wind speed increases significantly with altitude. The wind energy density in high altitude can reach several times or even dozens of times of that on the ground. The increase of wind speed reduces the wind sweeping area required for high-altitude wind power generation, and the wind power generation system can be miniaturized. Therefore, it is feasible to realize energy recovery by wind power generation during the cruising stage of the aircraft. The change of wind speed will cause the change of wind power generation efficiency. In order to maximize the utilization rate of wind energy, the generator conditions must be adjusted in real time according to the change of wind speed, so as to realize maximum power point tracking of wind power generation.

[0006] The present application combines the above technical background, and designs a distributed electric motor / generator integrated propulsion system based on a shaftless rim magnetic suspension fan for the shaftless rim electric propulsion configuration, including a distributed propulsion architecture, a compact shaftless rim magnetic suspension fan structure, an integrated bidirectional flow airfoil, and an improved maximum power point tracking algorithm, thereby realizing the multifunctional integration of distributed electric propellers, integration and high energy utilization. SUMMARY

[0007] In order to meet the development needs of green low-carbon, environmental protection and high efficiency of the aviation industry, and solve the problems of large fuel consumption and low energy utilization rate of traditional aviation propulsion, the application provides an electric / generation integrated distributed propulsion system based on shaftless rim magnetic suspension fan, wherein the electric / generation integration enables the magnetic suspension fan to switch between the functions of propeller and high-altitude wind power generator, serving as a propulsion unit and realizing the recycling of part of the high-altitude wind energy, further improving the energy utilization efficiency and reducing energy consumption; the distributed propeller improves the aerodynamic characteristics of the aircraft, improves the propulsion efficiency, and improves the safety performance and mission capability of the aircraft; the shaftless rim driving structure with electromagnetic bearing helps to realize high speed and lightweight of the supporting structure; the bidirectional flow airfoil (10) compatible with propulsion and power generation capacity does not affect the fan efficiency in the electric / generation integrated strategy, realizing the multi-functionality of the fan airfoil; the maximum power point tracking algorithm combined with the best tip speed ratio method and the hill climbing search method ensures the tracking speed and tracking accuracy, and further improves the wind energy utilization rate during power generation.

[0008] In order to achieve the above-mentioned purpose, the application provides an electric / generation integrated distributed propulsion system based on shaftless rim magnetic suspension fan, comprising a shaftless rim magnetic suspension fan (1), a turbo generator (2), an integrated controller (3), a bidirectional inverter (4), a battery (5) and an airborne electrical equipment (6).

[0009] The electric / generation integrated distributed propulsion system based on shaftless rim magnetic suspension fan, characterized in that the distributed shaftless rim magnetic suspension fan (1) has two working modes of electric and generation, the turbo generator (2) and the battery (5) can supply power to the integrated controller (3), directly driving the distributed shaftless rim magnetic suspension fan (1) to generate thrust, and part of the shaftless rim magnetic suspension fan (1) is converted into a generator working mode in high-altitude cruising state, charging the battery (5) through the bidirectional inverter (4), thereby further improving the high-altitude wind energy utilization rate.

[0010] The shaftless rim magnetic suspension fan (1) is distributed and arranged as a propeller / generator, the safety and mission capability of the aircraft are improved through redundant propeller arrangement and power generation characteristics; the distributed magnetic suspension fan increases the equivalent bypass ratio, improves the efficiency of the propulsion system, and the shaftless rim magnetic suspension fan (1) installed at the wing tip can reduce the induced drag and improve the aerodynamic characteristics of the aircraft.

[0011] The shaftless rim magnetic suspension fan (1) is composed of a stator shell structure (7), a ring type rotor (8), an integrated fan blade group (9) and a bidirectional flow blade type (10), and uses a magnetic suspension bearing to replace a mechanical bearing, adopts the ring type rotor (8) configuration, reduces the size and weight of the shaft structure, reduces the propulsion resistance, helps to realize high speed and light weight of the supporting structure, and improves the efficiency of the propeller.

[0012] The integrated fan blade group (9) adopts the bidirectional flow blade type (10) compatible with propulsion and power generation capacity, and the integrated fan blade group (9) is integrally manufactured by 3D printing and assembled in the ring type rotor (8) by interference fit, thereby improving the processing workability of the propulsion system.

[0013] The maximum power point tracking algorithm jointly uses the best tip speed ratio method and the hill climbing search method, the best tip speed ratio method is used to calculate and track the best speed to obtain the maximum wind energy utilization coefficient when the wind speed change rate is small, and the hill climbing search method is used to realize the rapid tracking of the maximum wind energy utilization coefficient when the wind speed change rate is large, so as to ensure the tracking speed and accuracy of the algorithm, improve the wind energy utilization rate during power generation, maximize the energy recovery, and charge the storage battery (5) through the bidirectional inverter (4).

[0014] Preferably, the shaftless rim magnetic suspension fan (1) adopts distributed propulsion, improves the aerodynamic characteristics of the aircraft, and improves the efficiency of the propulsion system.

[0015] Preferably, the shaftless rim magnetic suspension fan (1) adopts the ring type rotor (8) configuration, the stator shell structure (7) and the ring type rotor (8) are designed by integrating the electromagnetic bearing and the motor, the size and weight of the shaft structure are reduced, the propulsion resistance is reduced, the high speed and light weight of the supporting structure are realized, and the efficiency of the propeller is improved; the magnetic suspension bearing reduces the friction loss, is suitable for high speed fan working condition, and improves the efficiency and power density of the propeller.

[0016] Preferably, the integrated fan blade group (9) adopts the bidirectional flow blade type (10) compatible with propulsion and power generation capacity, which does not affect the fan efficiency in the motor and generator integrated strategy, and realizes the multi-functionality of the fan blade type.

[0017] Preferably, the maximum power point tracking algorithm uses the best tip speed ratio method or the hill climbing search method according to different wind speed change rates, ensures the tracking speed and accuracy of the algorithm, and improves the utilization rate of high altitude wind energy when the shaftless rim magnetic suspension fan (1) is in the power generation working state.

[0018] Overall, compared with the existing aviation propulsion system, the present application can achieve the following gains:

[0019] 1. The application provides an electric / generation integrated distributed propulsion system based on a shaftless rim magnetic suspension fan, which improves the safety performance of an aircraft, improves the aerodynamic characteristics of the aircraft and improves the propulsion efficiency.

[0020] 2. The application provides an electric / generation integrated distributed propulsion system based on a shaftless rim magnetic suspension fan, which reduces the structural weight, improves the power density of the propeller and the propulsion efficiency through a shaftless rim driving structure and an electromagnetic bearing.

[0021] 3. The application provides an electric / generation integrated distributed propulsion system based on a shaftless rim magnetic suspension fan, which enables the magnetic suspension fan to switch between the propeller and the high-altitude wind power generator function through a specially designed bidirectional flow airfoil (10), realizes the recycling of part of the energy, improves the energy utilization efficiency and reduces the energy consumption.

[0022] 4. The application provides an electric / generation integrated distributed propulsion system based on a shaftless rim magnetic suspension fan, which uses the maximum power point tracking algorithm to jointly use the best tip speed ratio method and the hill climbing search method, ensures the tracking speed and tracking accuracy, and improves the wind energy utilization rate during power generation. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the application, the drawings in the embodiments are briefly introduced below, which are used together with the embodiments of the application to explain the application and do not constitute a limitation on the application.

[0024] Figure 1 is a schematic diagram of an electric / generation integrated distributed propulsion system based on a shaftless rim magnetic suspension fan provided by the embodiments.

[0025] Figure 2 is a schematic diagram of a shaftless rim magnetic suspension fan structure provided by the embodiments.

[0026] Figure 3 is a schematic diagram of an integrated bidirectional flow airfoil structure of a shaftless rim magnetic suspension fan provided by the embodiments.

[0027] Figure 4 is a flowchart of a maximum power point tracking algorithm in an integrated controller provided by the embodiments.

[0028] In the drawings, 1. shaftless rim magnetic suspension fan, 2. turbogenerator, 3. integrated controller, 4. bidirectional inverter, 5. battery, 6. on-board electrical equipment, 7. stator shell structure, 8. ring rotor, 9. integrated fan blade group, 10. bidirectional flow airfoil DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0030] Figure 1 The embodiment provides a distributed propulsion system based on an axisless rim magnetic suspension fan, which is an electric / generation integrated distributed propulsion system based on an axisless rim magnetic suspension fan, comprising an axisless rim magnetic suspension fan (1), a turboshaft generator (2), an integrated controller (3), a bidirectional inverter (4), a storage battery (5), and an airborne electrical equipment (6).

[0031] The axisless rim magnetic suspension fan (1), the integrated controller (3), the bidirectional inverter (4) and the storage battery (5) are bidirectionally connected in the form of electric power, the turboshaft generator (2) is unidirectionally connected to the integrated controller (3) in the form of electric power, and the storage battery (5) provides electric power for the airborne electrical equipment (6).

[0032] The integrated controller (3) can realize aircraft energy management, motor driving control in the axisless rim magnetic suspension fan and bus control.

[0033] The distributed axisless rim magnetic suspension fan (1) has two working modes of electric driving and power generation, can be driven by the integrated controller (3) to generate thrust, is partially converted into a generator working mode in a high-altitude cruising state, and charges the storage battery (5) via the bidirectional inverter (4), so that the high-altitude wind energy utilization rate is further improved.

[0034] The axisless rim magnetic suspension fan (1) is distributedly arranged as a propeller / generator, a high-power and large-diameter magnetic suspension fan installed at a wing tip is a main propulsion device, a low-power and small-diameter magnetic suspension fan installed on a wing considers propulsion and power generation, the safety of an aircraft is improved through redundant propulsion and power generation capacity, the equivalent bypass ratio is increased, and the propulsion system efficiency is improved.

[0035] The turboshaft generator (2) is designed by integrating a turboshaft engine and a generator, the generator is connected with a power shaft of the turboshaft engine in a mechanical form, the conversion from fuel internal energy to mechanical energy to electric energy is completed, the fuel utilization rate and the system power density are improved.

[0036] Figure 2 The axisless rim magnetic suspension fan (1) provided by the embodiment is composed of a stator shell structure (7), a ring-shaped rotor (8), an integrated fan blade group (9) and a bidirectional flow airfoil (10), and highly integrates the functions of a magnetic suspension bearing and a permanent magnet synchronous motor.

[0037] Replace the mechanical bearing with the magnetic suspension bearing, the radial magnetic suspension bearing is arranged on both sides of the winding of the permanent magnet synchronous motor, the control performance of the radial magnetic bearing is improved, the axial size of the thruster is effectively reduced, and the friction loss and noise of the high-speed rotor are reduced.

[0038] The ring rotor (8) configuration is adopted, the hub is cancelled, the shaft structure size and weight are reduced, the propulsion resistance is reduced, high speed and light weight of the supporting structure are realized, and the propeller efficiency is improved.

[0039] Figure 3 The embodiment provides an integrated blade of the shaftless rim magnetic suspension fan, the bidirectional flow airfoil (10) uses a leaf type interpolation fusion method, the upper airfoil of NACA4412 suitable for power generation is fused to the lower airfoil of NACA2412 suitable for propulsion, so that the bidirectional flow airfoil has the characteristics of the two airfoils, and the integrated bidirectional flow airfoil of the motor / generator is compatible.

[0040] The bidirectional flow airfoil (10) is stressed on the upper airfoil during propulsion, and the wind acts on the lower airfoil during power generation, so that the fan blade maintains high efficiency in the two working conditions by fusing the upper and lower airfoil airfoils with different functions.

[0041] The integrated fan blade group (9) adopts the bidirectional flow airfoil (10) compatible with the propulsion and power generation capacity, is integrally manufactured by 3D printing, and is assembled in the ring rotor (8) in interference fit, and the machining process of the propulsion system is improved.

[0042] Figure 4 The maximum power point tracking algorithm used in the embodiment combines the optimal tip speed ratio tracking method and the hill climbing search method.

[0043] The optimal tip speed ratio control calculates the optimal speed of the generator at the moment through real-time wind speed and optimal tip speed ratio, and adjusts the speed of the motor in real time to achieve the optimal speed by using double closed loop control, so that the maximum power point tracking is realized, and the optimal wind energy utilization coefficient is obtained.

[0044] The hill climbing search method searches for the optimal speed by simulating the application of a small disturbance to the generator speed, so that the generator works at the maximum power point and the optimal wind energy utilization coefficient is obtained; the hill climbing search method used in the application selects a suitable step length for disturbance application based on the slope of the P-w curve, when the change of power exceeds a certain threshold or the slope of the curve is less than a certain value, it is considered that the maximum power point is reached, and the disturbance is stopped, when the calculated step length is greater than the set maximum step length, the amplitude is limited, and the electrical equipment is protected.

[0045] The switching of the optimal tip speed ratio method and the hill climbing search method is determined by the change rate of the current wind speed. When the change rate of the wind speed is small, the optimal tip speed ratio method is adopted; when the change rate of the wind speed is large, the hill climbing search method is switched, so as to ensure the tracking speed and tracking accuracy, improve the wind energy utilization rate of the shaftless rim magnetic suspension fan during power generation, maximize the energy recovery, and charge the storage battery (5) through the bidirectional inverter (4).

[0046] The above examples are only used to clearly illustrate the technology and characteristics of the present application, so that those skilled in the art can easily understand and implement it, and are not used to limit the present application. Any modification, equivalent replacement and improvement made without departing from the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An electric / generation integrated distributed propulsion system based on shaftless rim magnetic levitation fan, characterized in that, The application relates to a distributed shaftless magnetic suspension fan (1), a turbo generator (2), an integrated controller (3), a bidirectional inverter (4), a storage battery (5) and airborne electrical equipment (6); the turbo generator (2) and the storage battery (5) drive the distributed shaftless magnetic suspension fan (1) through the integrated controller (3) to provide thrust for an aircraft; the shaftless magnetic suspension fan (1) is compatible with two working modes of propulsion and power generation and can be converted between the two working modes; mechanical bearings are replaced by magnetic suspension bearings; a ring-shaped rotor (8) configuration is adopted; a central hub is cancelled; and a permanent magnet synchronous motor and an electromagnetic bearing are compactly integrated; when the aircraft is cruising at a high altitude, part of the distributed shaftless magnetic suspension fan (1) is adjusted into a high-altitude power generation mode through bidirectional flow airfoils (10); the maximum power point tracking algorithm in the integrated controller (3) is used to obtain an optimal wind energy utilization coefficient; and the maximum output power is charged to the storage battery (5) to maximize the output power. The shaftless magnetic suspension fan (1) is composed of a stator shell structure (7), a ring-shaped rotor (8), an integrated fan blade group (9) and bidirectional flow airfoils (10). The integrated controller (3) adopts the maximum power point tracking algorithm in the power generation state of the shaftless magnetic suspension fan (1), and the best tip speed ratio method and the hill climbing search method are jointly used; when the wind speed change rate is small, the best tip speed ratio method is used to calculate and track the optimal rotating speed to obtain the maximum wind energy utilization coefficient; and when the wind speed change rate is large, the hill climbing search method is used to realize the rapid tracking of the maximum wind energy utilization coefficient. Radial magnetic suspension bearings are arranged on both sides of the winding of the permanent magnet synchronous motor. The optimal tip speed ratio control calculates the optimal rotating speed of the generator at the moment through the real-time wind speed and the optimal tip speed ratio, and the rotating speed of the motor is adjusted in real time to reach the optimal value by using double closed-loop control, so that the maximum power point tracking is realized, and the optimal wind energy utilization coefficient is obtained. The hill climbing search method searches for the optimal rotating speed by simulating the application of a slight disturbance to the rotating speed of the generator, so that the generator works at the maximum power point and the optimal wind energy utilization coefficient is obtained; the hill climbing search method is used, a suitable step is selected based on the slope of the P-w curve to apply the disturbance, when the change of the power exceeds a certain threshold value or the slope of the curve is less than a certain value, it is considered that the maximum power point is reached, and the disturbance is stopped, and when the calculated step is greater than the set maximum step, the step is limited, and the electrical equipment is protected.

2. The electric / generation integrated distributed propulsion system based on the shaftless rim magnetic levitation fan according to claim 1, characterized in that, The distributed shaftless magnetic suspension fan (1) has two working modes of motor driving and power generation; the turbo generator (2) and the storage battery (5) can supply power to the integrated controller (3) to directly drive the distributed shaftless magnetic suspension fan (1) to generate thrust; part of the shaftless magnetic suspension fan (1) is converted into a generator working mode in the high-altitude cruising state, and the bidirectional inverter (4) is used to charge the storage battery (5), so that the high-altitude wind energy utilization rate is further improved.

3. The electric / generator integrated distributed propulsion system based on the shaftless rim magnetic levitation fan according to claim 1, characterized in that, The integrated fan blade group (9) adopts the bidirectional flow airfoil (10) compatible with the propulsion and power generation capacity, is integrally manufactured by 3D printing, is assembled in the ring-shaped rotor (8) in interference fit, and the machining process of the propulsion system is improved.

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