Aircraft electric propulsion system and wing distributed electric propeller propulsion aircraft

Abstract

The embodiment of the specification discloses an aircraft electric propulsion system, the system comprises a power generation subsystem, a power distribution subsystem and a propulsion subsystem, the power generation subsystem comprises a turboshaft engine and a generator; the turboshaft engine is arranged at the tail part of the aircraft and is used for driving the generator to generate electricity; wherein a fan of the turboshaft engine is used for sucking low-speed air of a fuselage boundary layer into the turboshaft engine; the power distribution subsystem is used for distributing power to the propulsion subsystem, and the propulsion subsystem drives an aircraft; wherein the electric power comprises electric power from a power generation subsystem.

Description

Technical Field

[0001] The present application relates to the field of aircraft aerodynamic layout design and power architecture technology, and in particular to aircraft electric propulsion systems and wing-distributed electric propeller-propelled aircraft. Background Art

[0002] While air transportation provides a fast and convenient way of travel, it also brings serious pollution problems. In response to this challenge, the aviation industry has carried out a lot of technological innovation research and proposed a variety of emission reduction solutions. The integrated design of the aircraft fuselage and engine is an advanced aerodynamic optimization design technology and one of the ways to improve fuel efficiency. Currently, combined with the development of hybrid aircraft and electric propulsion technology, boundary layer ingestion (BLI-boundary layer ingestion) and distributed propulsion (DP-distributed propulsion) technology are important ways to improve the propulsion efficiency of the entire aircraft.

[0003] Among them, BLI technology can improve propulsion efficiency, reduce aircraft wake loss and speed loss, and reduce propulsion power consumption under the same thrust. At the same time, it can reasonably organize the airflow composition of the entire aircraft and realize potential aerodynamic benefits. Distributed propulsion can improve the equivalent bypass ratio of the entire aircraft, thereby improving the propulsion efficiency of the entire aircraft.

[0004] In the prior art, the propulsion system usually includes two turbofan engines installed under the wing, wherein part of the shaft power of the two turbofan engines is used to drive the generator. At the same time, the propulsion system combines boundary layer intake technology to deliver a part of the slower air in the boundary layer of the fuselage and / or wing to the electric ducted fan driven by electric energy at the tail of the fuselage and / or wing, thereby reducing resistance and improving the efficiency of the entire aircraft by re-stimulating the boundary layer air flow downstream of the aircraft. The electric ducted fan usually circles the fuselage axis to obtain the maximum benefit of the entire aircraft. Part of the shaft power of the turbofan engine (i.e., part of the turbine electric solution) generates electricity as the energy supply end of the electric propulsion system, and the other part of the shaft power is used as a traditional solution to provide thrust to the engine's ducted fan. However, since the slower boundary layer airflow entering the turbofan jet engine has an uneven velocity distribution, this will cause the inlet airflow of the electric ducted fan to be distorted. Summary of the invention

[0005] The embodiments of this specification provide an aircraft electric propulsion system and a wing-distributed electric propeller-propelled aircraft, which are used to solve the technical problem of how to improve the propulsion efficiency of the aircraft.

[0006] The embodiment of this specification provides an aircraft electric propulsion system, the system comprising a power generation subsystem, a power distribution subsystem and a propulsion subsystem, the power generation subsystem comprising a turboshaft engine and a generator;

[0007] The turboshaft engine is arranged at the tail of the aircraft and is used to drive the generator to generate electricity; wherein the fan of the turboshaft engine is used to draw low-speed air in the boundary layer of the fuselage into the turboshaft engine;

[0008] The power distribution subsystem is used to distribute electric power to the propulsion subsystem, and the propulsion subsystem drives the aircraft; wherein the electric power includes electric power from the power generation subsystem.

[0009] Optionally, there are two turboshaft engines, which are respectively installed on both sides of the tail of the aircraft, and each turboshaft engine drives a generator.

[0010] Optionally, the power generation subsystem further includes a rectifier, which is used to convert the alternating current generated by the generator into high-voltage direct current, and the power from the power generation subsystem is the high-voltage direct current.

[0011] Optionally, the system further comprises a frequency conversion device, which is used to convert direct current from the power distribution subsystem into alternating current and provide the converted alternating current to the propulsion subsystem.

[0012] Optionally, the system further includes an energy storage subsystem, and the electricity includes electricity from the energy storage subsystem.

[0013] Optionally, the energy storage subsystem includes a lithium battery pack; wherein the power generation subsystem is used to provide steady-state power, and the lithium battery is used to provide / absorb transient power;

[0014] or,

[0015] The energy storage subsystem includes a lithium battery pack. When the SOC of the lithium battery reaches a preset condition, the power generation subsystem supplies power to the lithium battery.

[0016] Optionally, the power distribution subsystem includes an electric energy management system, and the electric energy management system is used to distribute electricity according to an electric energy distribution strategy.

[0017] Optionally, the propulsion device includes a motor and a propeller; the motor is used to convert electrical energy into mechanical energy, drive the propeller to rotate, and provide thrust for the aircraft.

[0018] An embodiment of the present specification provides a wing-distributed electric propeller-propelled aircraft, wherein the aircraft includes any of the above-described aircraft electric propulsion systems.

[0019] Optionally, the aircraft further includes a thermal management system, which is used to manage the heat dissipation and / or air-conditioning system of the aircraft, and the thermal management system draws power from the power generation subsystem.

[0020] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0021] The power architecture scheme of extracting electric energy from the turboshaft engine at the tail of the fuselage includes installing the turboshaft engine at the tail of the aircraft and utilizing the boundary layer airflow at the tail of the fuselage to draw the low-speed air in the boundary layer of the fuselage into the turboshaft engine. This can effectively improve the working efficiency of the turboshaft engine, thereby improving the power generation efficiency of the power generation subsystem and the propulsion efficiency of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings required for use in the embodiments of this specification or the prior art description are briefly described below. Obviously, the following only describes the drawings required for use in some embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0023] Figure 1 It is a schematic diagram of the engine high pressure shaft power extraction in the first embodiment of this specification.

[0024] Figure 2 Schematic diagram of the component layout of the electric propulsion system in the first embodiment of this specification.

[0025] Figure 3 It is a schematic diagram of the installation and aerodynamic layout of the turboshaft engine in the first embodiment of this specification.

[0026] Figure 4 It is a schematic diagram of energy flow of the electric propulsion system in the first embodiment of this specification.

[0027] Figure 5 It is a schematic diagram of the architecture of the electric propulsion system in the first embodiment of this specification.

[0028] Figure 6 It is a schematic diagram of the information interaction relationship between the power management system and other components in the first embodiment of this specification.

[0029] In the figure: 1, turboshaft engine; 2, generator set; 3, rectifier; 4, switchboard box; 5, inverter; 6, motor; 7, electric propulsion propeller; 8, lithium battery pack; 9, thermal management system (TMS); 10, cables; 11, wingtip propeller. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments involved in the specific implementation methods are only part of the embodiments of this application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the specific implementation methods without making creative work should belong to the scope of protection of this application.

[0031] The first embodiment of the present specification (hereinafter referred to as “Embodiment 1”) provides an aircraft electric propulsion system, which can provide thrust for the aircraft.

[0032] The aircraft electric propulsion system provided in Example 1 includes a power generation subsystem (or power generation system), a power distribution subsystem and a propulsion subsystem (or propulsion motor system), wherein the power generation subsystem includes a turboshaft engine and a generator.

[0033] The turboshaft engine is arranged at the tail of the aircraft and is used to drive the generator to generate electricity; wherein the fan of the turboshaft engine is used to suck the low-speed air of the fuselage boundary layer into the turboshaft engine.

[0034] The power distribution subsystem is used to distribute electric power to the propulsion subsystem, and the propulsion subsystem drives the aircraft; wherein the electric power includes electric power from the power generation subsystem.

[0035] Preferably, there are two turboshaft engines, which are respectively installed on both sides of the tail of the aircraft, and each turboshaft engine converts the chemical energy of aviation kerosene into mechanical energy. The generator is used as a source of electric power required by the aircraft, and each turbine engine can drive a generator to generate electricity. The generator can be an internal rotor generator, and the type of the generator can be a permanent magnet synchronous generator.

[0036] Taking the aircraft as an example, a pair of high-pressure ratio turboshaft engines can be installed on both sides of the tail of the aircraft fuselage. Specifically, the turboshaft engine can be installed on the fuselage through a structural support system, and preferably the turboshaft engine is half-buried in the fuselage. According to the principle of BLI technology, the drag is reduced and the propulsion efficiency of the turboshaft engine is improved by re-stimulating the boundary layer air flow near the fuselage. Therefore, the embedded installation parameters of the turboshaft engine are related to the local fuselage boundary layer state. It is preferred that the length of the engine blade exposed outside the fuselage is 90% of the local boundary layer thickness. The formula for estimating the thickness of the local boundary layer is:

[0037]

[0038] Where δ is the boundary layer thickness, x is the distance between the engine fan inlet and the nose, Re x=ρVx / μ is the characteristic Reynolds number, ρ is the air density, V is the flight speed, μ is the air viscosity coefficient,

[0039] The fan of the turboshaft engine rotates around the central axis of the turboshaft engine, and the low-speed air in the boundary layer of the fuselage is sucked into the turboshaft engine through the fan to mix with the aviation fuel, burn, expand to do work, drive the turbine bearings, exhaust, and generate a part of the thrust. The turbine shaft of the turboshaft engine is mechanically connected to the corresponding generator, which is installed on the corresponding turboshaft engine nacelle accessory gearbox and draws electricity through the high-pressure shaft of the turbine engine. Specifically, the high-pressure shaft drives the central transmission mechanism, and then connects to the generator through the accessories to realize the conversion of the mechanical energy of the turbine engine into electrical energy, for example Figure 1 shown.

[0040] The parameters of the generator and the turboshaft engine may be, for example: the generator is preferably a high-power generator, the total power output level of the two generators is 12MW-20MW, and the speed range of the generator is 3300-5500RPM; the speed range of the turboshaft engine is 12000-20500RPM, its rated power density is not less than 10kw / Kg, the rated efficiency should be 95-98%, and it is cooled by lubricating oil.

[0041] The power distribution subsystem is used to manage and distribute power. The functions of the power distribution subsystem are: first, to provide the power required for the thrust of the aircraft; second, to provide the power required for other systems of the aircraft, such as avionics, hydraulic systems, etc.; third, to provide the power required for cabin air conditioning and cooling air after the APU is removed. Preferably, the power distribution subsystem can be a distribution panel box, which is installed in the rear electronic equipment EE compartment of the aircraft.

[0042] The power managed or configured by the distribution subsystem includes power from the power generation subsystem. The power from the power generation subsystem may include power generated by the above-mentioned generator, or the power from the power generation subsystem may refer to power generated by the above-mentioned generator and rectified. If the latter, the power generation subsystem may also include a rectifier, which is used to convert the alternating current generated by the generator into high-voltage direct current, and the power from the power generation subsystem is the high-voltage direct current converted by the rectifier. Preferably, the rectifier may be a rectifier, and the parameters of the rectifier are, for example: a rated output voltage of 1028VDC, a rated power density of not less than 18kw / Kg, a rated efficiency of 98-99%, and cooling by means of a propylene glycol-water mixture.

[0043] The aircraft electric propulsion system may further include an energy storage subsystem, and the electric power managed or configured by the power distribution subsystem may further include electric power from the energy storage subsystem.

[0044] Preferably, the energy storage subsystem includes a lithium battery pack (the energy storage subsystem may also be referred to as a lithium battery system), and the power from the energy storage subsystem includes power from the lithium battery pack. The power generation subsystem is used to provide steady-state power, and the lithium battery is used to provide / absorb transient power. After the lithium batteries are grouped, the parameters of the lithium battery pack are, for example: the energy density is not less than 600-800Wh / kg.

[0045] The energy storage subsystem may also include some accessories of the lithium battery pack, such as a converter and a heat sink, which are not limited to the first embodiment.

[0046] The aircraft electric propulsion system may also include a fuel cell (or fuel cell system), and the power managed or configured by the power distribution subsystem may also include power from the fuel cell, wherein the fuel cell is used to provide steady-state power.

[0047] Preferably, the power distribution subsystem may include an electric energy management system (or energy management system), which is used to distribute electricity according to the electric energy distribution strategy. Among them, the above-mentioned distribution panel box may belong to the electric energy management system, and the electric energy management system may also include an electric energy management controller. Specifically, the electric energy management system obtains the status of power equipment such as generators, lithium battery packs, fuel cells, and propulsion motors through the electric energy management controller, and sends electric power distribution instructions and propulsion motor control instructions to the electric energy management controller; obtains the status of the turboshaft engine through the engine control system, and sends the thrust instructions required to be provided to the engine controller of the turboshaft engine to control the working state of the turboshaft engine.

[0048] Specific power distribution strategies include:

[0049] 1) During the taxiing-in and taxiing-out phases of the aircraft, the energy storage subsystem is independently powered to provide taxiing thrust.

[0050] 2) During the takeoff, climb, cruise and approach phases of the aircraft, the power generation subsystem and the energy storage subsystem jointly provide the required thrust, and switch and redistribute the energy sources according to the thrust requirements of the entire aircraft.

[0051] 3) During the descent phase, the power generation subsystem charges the energy storage subsystem in the air to provide energy for the next ground electric gliding.

[0052] Preferably, when the SOC (State of Charge: the available state of the remaining charge in the battery) of the lithium battery reaches a preset condition (for example, the SOC of the lithium battery is lower than a preset value), the power generation subsystem and / or the fuel cell supplies power to the lithium battery.

[0053] The aircraft electric propulsion system may also include a frequency conversion device, which is used to convert the direct current from the power distribution subsystem into alternating current and provide the converted alternating current to the propulsion subsystem. Preferably, the frequency conversion device may be a frequency converter (or motor controller), which is installed in the mid-front EE compartment. The parameters of the frequency converter are, for example: the rated input voltage is 1028VDC, the rated power density is not less than 20kw / Kg, the rated efficiency is 98-99%, and the cooling is performed by means of a propylene glycol-water mixture.

[0054] In the first embodiment, the propulsion subsystem may include a motor (or propulsion motor) and a propeller. The motor converts electrical energy into mechanical energy (ie, the propulsion work of the aircraft), drives the propeller to rotate, and provides thrust for the aircraft.

[0055] The electric energy received by the motor can come from the above-mentioned frequency conversion device. Preferably, the motor is installed on the leading edge of the wing of the aircraft. The parameters of the motor are, for example: the speed range is 3300-5500RPM, the rated power density is not less than 10kw / Kg, the rated efficiency is 95-98%, and it is cooled by lubricating oil / deionized water (water+propylene glycol).

[0056] The propeller (or electric propulsion propeller) is connected to the motor or motor reducer, and rotates under the drive of the motor or motor reducer to provide the thrust required by the aircraft. The parameters of the propeller are as follows: the speed range is 3000-3500RPM.

[0057] In the first embodiment, the design parameters of the aircraft electric propulsion system include power transmission efficiency, battery energy ratio to the total aircraft energy, and component power density.

[0058] Among them, the power transmission efficiency η Tr The expression of is as follows (1):

[0059] η Tr =η G *η R *η PL *η C *η M (1)

[0060] In formula (1): G is the overall generator efficiency, η R is the efficiency of the rectifier, η PL is the efficiency of the power distribution device, η C is the frequency conversion device controller efficiency, η M is the overall motor efficiency.

[0061] The total energy efficiency of the aircraft η Ov The expression of is as follows (2):

[0062] ηOv =η th *η Tr *η P =P req / P supply =F N *V / (P batt +P fuel ) (2)

[0063] In formula (2): th is the conversion efficiency of all turboshaft engines, η P is the propulsion efficiency of all thrusters, P req is the required power of the entire aircraft, P supply is the power that the entire aircraft can provide, P batt is the power that the lithium battery pack can provide, P fuel is the power that the fuel can provide, F N is the thrust required for the aircraft, and V is the flight speed of the aircraft.

[0064] Power from fuel P fuel The expression is as follows:

[0065] P fuel =m fuel *FHV;

[0066] Among them, m fuel is the fuel flow rate, and FHV is the calorific value of the fuel.

[0067] The expression for the proportion of electrical energy to the total propulsion energy of the aircraft is as follows:

[0068] Θ=P SUPPLY_Elec / P tot

[0069] Among them, P SUPPLY_Elec is the power provided by the electric energy, P tot is the total propulsion power.

[0070] Some technical indicators of the aircraft electric propulsion system can be shown in Table 1 below (Table 1 is only an example):

[0071]

[0072] Table 1

[0073] Combine the following Figures 2 to 5 Taking a conventional cylindrical-wing aircraft as an example, the content of the first embodiment is further described:

[0074] refer to Figure 2 A pair of high-pressure ratio turboshaft engines 1 (i.e., core engines, such as Figure 3 As shown), recorded as the left engine and the right engine ("left" and "right" here are only used to distinguish the engines, and are not used to limit the specific position or direction, nor are they used to limit the first embodiment). Each turboshaft engine 1 is connected to a generator, and the two generators form a generator set 2. Each generator is connected to a rectifier 3, and the rectifier 3 and the lithium battery pack 8 are connected to the distribution panel box 4, and the distribution panel box 4 is connected to the inverter 5. Among them, the rectifier 3, the lithium battery pack 8, the distribution panel box 4, and the inverter 5 can be arranged in sequence along the center axis direction of the aircraft fuselage or along the direction from the tail to the nose.

[0075] A plurality of motors 6 are installed on the wings on both sides of the aircraft, and the frequency converter 5 is connected to each motor 6. The plurality of motors 6 on a single wing are sequentially arranged and distributed along the extension direction of the wing, and adjacent motors 6 are spaced a certain distance apart, and each motor 6 is connected to an electric propeller 7, that is, the electric propellers 7 on both sides of the fuselage are also distributedly arranged.

[0076] The above components can be connected in a suitable manner, for example, the turboshaft engine 1 and the generator can be mechanically connected, and some components can be connected by high-voltage cables 10 to transmit current or high-voltage current. The specific connection method is not limited to the first embodiment.

[0077] refer to Figure 4 and Figure 5 In actual application, the two turboshaft engines 1 and the generator set 2 installed at the tail of the fuselage are used to generate all the electrical energy required by the whole aircraft. At the same time, the boundary layer airflow at the tail of the fuselage can improve the propulsion efficiency of the turboshaft engine 1. The rectifier 3 is used to convert the alternating current generated by the generator into high-voltage direct current, thereby improving the power transmission efficiency of the whole aircraft.

[0078] The lithium battery pack 8 is used to provide auxiliary power for the aircraft. The switchboard box 4 is used to secondary distribute the DC power converted by the rectifier 3 and the DC power generated by the lithium battery pack 8 for use by the whole machine. The frequency converter 5 receives the high-voltage DC power distributed by the switchboard box 4, converts the high-voltage DC power into AC power, and provides the AC power to each motor 6. The motor 6 converts the electrical energy into mechanical energy, drives the electric propeller 7 to rotate, and the electric propeller 7 provides the propulsion power of the aircraft.

[0079] The power transmission of the whole machine can be carried out through the cable 10.

[0080] refer to Figure 5, two generators provide 1028V high-voltage DC power, combined with fuel cells and lithium batteries to provide auxiliary power supply, and four channel power supplies are concentrated in the high-voltage DC power distribution system (including distribution panel box and inverter) to power each motor. Among them, the power generation subsystem and fuel cell system provide steady-state power, and the lithium battery system provides / absorbs transient power. When the lithium battery SOC in the lithium battery pack is low, for example, lower than the preset value, the power generation subsystem and fuel cell system can charge the lithium battery.

[0081] The power management system can exchange information with other systems. Specific cross-linking instructions include Figure 6 shown.

[0082] Embodiment 1 can achieve the following beneficial effects:

[0083] The power architecture scheme of extracting electric energy from the turboshaft engine at the tail of the fuselage includes installing the turboshaft engine at the tail of the aircraft and utilizing the boundary layer airflow at the tail of the fuselage to draw the low-speed air in the boundary layer of the fuselage into the turboshaft engine. This can effectively improve the working efficiency of the turboshaft engine, thereby improving the power generation efficiency of the power generation subsystem and the propulsion efficiency of the aircraft.

[0084] In particular, the first embodiment uses two turboshaft engines with air intakes on both sides of the tail of the fuselage, realizing an aerodynamic layout of air intakes on both sides of the tail of the fuselage based on the BLI technology, actively inhaling the boundary layer of the fuselage, which can reduce the fuselage resistance of the aircraft, improve the propulsion efficiency of the aircraft, and reduce the consumption of aviation fuel. In addition, the use of two turboshaft engines improves the redundancy of power and reduces the difficulty of designing the power system.

[0085] Multiple distributed all-electric propellers are installed on the wings. When some power units (including a single motor and / or a single propeller) fail, other power units can still provide thrust for the aircraft, thereby improving the safety of the aircraft.

[0086] Through the scheme of the first embodiment, high voltage direct current, such as 1024V high voltage direct current, can be provided and transmitted, and the power transmission efficiency from the generator to the propulsion motor is not less than 90%-94%, thereby improving the power transmission efficiency of the entire aircraft. In addition, the overall power density of the aircraft electric propulsion system (excluding lithium batteries and thermal management systems, which will be described below) is not less than 1.2-1.8kW / kg.

[0087] Through the mutual coordination of power generation subsystem, distribution subsystem, energy storage subsystem, etc., and following the power distribution strategy, the energy system of the entire machine can be aggregated and redistributed to improve the efficiency of power utilization.

[0088] Embodiment 1 has broad application prospects and can be applied to subsonic / high subsonic aircraft, including general aviation, regional and single-aisle low-subsonic passenger aircraft, cargo aircraft, unmanned aerial vehicles and other types of aircraft, and can enhance the aircraft-propulsion integrated design capability.

[0089] The second embodiment of the present specification (hereinafter referred to as "Embodiment 2") provides a wing-distributed electric propeller-propelled aircraft, wherein the aircraft includes the aircraft electric propulsion system described in Embodiment 1.

[0090] A specific example of the second embodiment is as follows Figure 2 As shown, a combined aircraft solution of using double-sided air intakes at the rear of the fuselage (i.e., twin turboshaft engines) BLI technology + turboshaft engine power extraction (i.e., power drawn from the power generation subsystem) + distributed electric propeller propulsion installed on the wings is used on a traditional configuration aircraft.

[0091] In the second embodiment, the aircraft further comprises a thermal management system, which is used to manage the heat dissipation and / or air conditioning system of the aircraft, and the thermal management system draws power from the power generation subsystem.

[0092] refer to Figure 4 The thermal management system 9 is used to uniformly plan the electrical components of the entire aircraft. As an example, the thermal management system 9 includes a fuel circulation subsystem, which uses fuel as the main heat sink. The fuel circulation subsystem connects the various components of the electric propulsion system. The fuel supplied from the wing fuel supply tank is transported to the corresponding subsystems or components of the aircraft electric propulsion system in sequence along the oil pipeline, such as the power distribution subsystem, the energy storage subsystem, and the motor in the propulsion subsystem. Part of the fuel is used to cool the corresponding subsystem or component, and the other part is passed through the booster pump, and after being pressurized, it is mixed with the fuel that has passed through the corresponding subsystem or component and absorbed heat, and then enters the turboshaft engine at the tail. In addition, the thermal management system 9 can allocate the fuel consumption according to the working state of the turboshaft engine. If the turboshaft engine works in a low thrust state, the excess fuel is mixed with the cold air of the environmental control system and then transported to the cabin. The overall power density of the thermal management system 9 is not less than 0.68-0.8kW / kg.

[0093] The environmental control system draws power from the power distribution subsystem, such as the high-voltage DC busbar in the distribution panel box, and provides 115V / 400Hz three-phase AC power through a DC-AC converter. The backup air supply provides the air flow required for starting the above-mentioned turboshaft engine and the air conditioning package through an electric compressor.

[0094] In addition, if Figure 2 As shown, a wingtip propeller 11 is installed at the wingtip of the aircraft wing to reduce the induced drag caused by the pressure difference between the upper and lower wingtips.

[0095] The contents not described in detail in the second embodiment may refer to the first embodiment. The second embodiment can achieve the same beneficial effects as the first embodiment, and the various embodiments may be used in combination.

[0096] The above is only an embodiment of this specification and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An aircraft electric propulsion system, characterized in that: The system includes a power generation subsystem, a power distribution subsystem and a propulsion subsystem, wherein the power generation subsystem includes a turboshaft engine and a generator; The turboshaft engine is arranged at the tail of the aircraft and is used to drive the generator to generate electricity; wherein the fan of the turboshaft engine is used to draw low-speed air in the boundary layer of the fuselage into the turboshaft engine; The power distribution subsystem is used to distribute electric power to the propulsion subsystem, and the propulsion subsystem drives the aircraft; wherein the electric power includes electric power from the power generation subsystem.

2. The system according to claim 1, characterized in that There are two turboshaft engines, which are respectively installed on both sides of the tail of the aircraft, and each turboshaft engine drives a generator.

3. The system according to claim 1, characterized in that The power generation subsystem further includes a rectifier, which is used to convert the alternating current generated by the generator into high-voltage direct current, and the power from the power generation subsystem is the high-voltage direct current.

4. The system according to claim 1, characterized in that The system further comprises a frequency conversion device for converting direct current from the power distribution subsystem into alternating current and providing the converted alternating current to the propulsion subsystem.

5. The system according to claim 1, wherein: The system further includes an energy storage subsystem, and the electric power includes electric power from the energy storage subsystem.

6. The system according to claim 5, characterized in that The energy storage subsystem includes a lithium battery pack; wherein the power generation subsystem is used to provide steady-state power, and the lithium battery is used to provide / absorb transient power; or, The energy storage subsystem includes a lithium battery pack. When the SOC of the lithium battery reaches a preset condition, the power generation subsystem supplies power to the lithium battery.

7. The system according to claim 1, characterized in that The power distribution subsystem includes an electric energy management system, which is used to distribute electricity according to an electric energy distribution strategy.

8. The system according to any one of claims 1 to 7, characterized in that The propulsion device includes a motor and a propeller; the motor is used to convert electrical energy into mechanical energy, drive the propeller to rotate, and provide thrust for the aircraft.

9. A wing-distributed electric propeller-propelled aircraft, characterized in that: The aircraft comprises an aircraft electric propulsion system according to any one of claims 1 to 7.

10. The aircraft according to claim 9, characterized in that The aircraft further comprises a thermal management system, which is used to manage the heat dissipation and / or air conditioning system of the aircraft, and the thermal management system draws power from the power generation subsystem.

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