Range extender generator for 30000-turn electric aircraft

Abstract

The invention discloses a range extender generator for a 30000-turn electric aircraft, which adopts a mode that an inner rotor has 18 slots, 10 poles and five sections of rotor iron core skewed slot magnetic steel is radially inserted, and has the excellent performances of symmetrical magnetomotive force waveform, high winding coefficient, low torque pulsation and cogging torque and no end ring current. The motor adopts a centralized winding, winding oil cooling and shell water cooling mode, and is suitable for a generator for a range extender of an electric aircraft.

Description

[Technical field]

[0001] The invention belongs to the technical field of motors, and in particular relates to a 30,000-rpm range extender generator for electric aircraft. [Background technology]

[0002] As the low-altitude economy develops faster and faster, electric propulsion aircraft have higher and higher requirements for extending their range. The current range of eVTOL aircraft is limited by the weight of the battery pack that can be installed, and the range is generally less than 200 kilometers. The use of a range extender can extend the range.

[0003] Therefore, it is necessary to provide a new 30,000-rpm range extender generator for electric aircraft to solve the above technical problems. [Summary of the invention]

[0004] The main purpose of the present invention is to provide a 30,000 rpm range extender generator for electric aircraft, which has the excellent performance of symmetrical magnetomotive force waveform, high winding coefficient, low torque pulsation and cogging torque, and no end circulation.

[0005] The present invention achieves the above-mentioned object through the following technical solutions: a 30,000-rpm range extender generator for electric aircraft, comprising a stator and a rotor arranged inside the stator; the stator comprises a stator core and a winding, the inner wall of the stator core is provided with a plurality of stator slots at equal angles along its own circumference, and each of the stator slots is provided with the winding; the rotor comprises a rotor core and a magnetic steel group, the outer wall of the rotor core is provided with a plurality of accommodating cavities at equal angles along its own circumference, and each of the accommodating cavities is provided with a group of magnetic steel groups; the characteristics are:

[0006] The number of the stator slots is 18, and the number of the magnetic steel groups is 10, forming an 18-slot 10-pole matching structure;

[0007] The winding adopts concentrated winding;

[0008] The stator core has an outer diameter D1=262 mm and an inner diameter D2=182 mm;

[0009] The outer diameter D3 of the rotor core is 177 mm, and the inner diameter D4 is 138 mm;

[0010] The air gap between the stator and the rotor is L1=2.5 mm;

[0011] The slot width L2 of the stator slot is 6 mm, the slot depth L3 is 27 mm, the slot tip angle θ1 is 40°, and the stator slot is a parallel slot with a parallel slot width L4 of 11 mm;

[0012] The rotor adopts five-stage pole tilting treatment, and the pole tilting treatment angles are: -1.714°, -0.857°, 0°, 0.857°, and 1.714°.

[0013] Furthermore, a stator tooth is formed between two adjacent stator slots, and the air gap is formed between the inner wall of the stator tooth and the outer wall of the magnetic steel group.

[0014] Furthermore, the pole arc angle θ2 = 152°.

[0015] Furthermore, the group of magnetic steel groups forms a pole, and the pole includes 20 magnetic steels.

[0016] Furthermore, the thickness L5 of the magnetic steel in the magnetic steel group is 5.5 mm, and the magnetic steel is inserted into the accommodating cavity in a radial insertion manner.

[0017] Furthermore, the magnetic steel adopts 52UH NdFeB magnetic steel with a remanence of 1.46T and a maximum operating temperature of 180°C.

[0018] Furthermore, the winding is made of corona-resistant polyimide copper flat wire with a temperature resistance grade of 240° C., and a single wire is wound with 6 turns.

[0019] Furthermore, the filling rate of the stator slots is 89.06%.

[0020] Furthermore, the stator slot is provided with insulating paper for isolating the inner wall of the stator slot from the winding; the insulating paper is made of DuPont Nomex T410 aramid insulating paper with a thickness of 0.25 mm; the gap of the winding in the stator slot is filled with insulating varnish, and the insulating varnish is made of VX4201 unsaturated polyester imide resin.

[0021] Furthermore, the stator core and the rotor core are formed by stacking silicon steel sheets, the stator core uses 0.1mm thick JFE10JNX900 silicon steel sheets, the rotor core uses 0.25mm thick 25WY900 high yield strength silicon steel sheets, the core stacking height of the stator core and the rotor core is 50mm, and the stacking coefficient is 0.97.

[0022] Furthermore, a cooling shell is provided on the outer periphery of the stator, and a first cooling medium circulates in the cooling shell; an inner retaining ring is provided on the inner side of the rotor, and a cooling cavity that encloses the stator and the rotor is formed between the inner retaining ring and the cooling shell, and the upper and lower ends of the cooling cavity are sealed by end covers; a second cooling medium circulates in the cooling cavity.

[0023] Furthermore, the outer circumference of the rotor is provided with a sheath to prevent the magnetic steel from flying out, the sheath is made of carbon fiber, and the thickness of the carbon fiber sheath is 1.5 mm.

[0024] Compared with the prior art, the beneficial effects of the 30,000-rpm range extender generator for electric aircraft of the present invention are: by optimizing the design in the main aspects such as motor material selection, magnetic steel arrangement method, skewed pole processing method, winding form, etc., it is applied to electric propulsion aircraft; the inner rotor 18 slots, 10 poles, five-segment rotor core skewed slot magnetic steel is radially inserted, and it has excellent performances of symmetrical magnetomotive force waveform, high winding coefficient, low torque pulsation and cogging torque, and no end circulation; the motor adopts centralized winding, winding oil cooling, and shell water cooling. The power generation voltage is 762.6V, the current is 400A, the stack height is 50mm, the electromagnetic part weighs 14.79Kg, the motor weighs about 24Kg, the generator power is 305.04KVA, and the generator power density is as high as 12.71KVA / kg.

Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of a horizontal cross-sectional structure of an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the structure of the winding in the stator slot in an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of a local structure in an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the longitudinal cross-sectional structure of an embodiment of the present invention;

[0029] Figure 5 This is a magnetomotive force waveform diagram of an embodiment of the present invention using an 18-slot 10-pole matching method;

[0030] Figure 6 This is a BH curve diagram of the 25WY900 high yield strength silicon steel sheet (0.25 mm) according to the embodiment of the present invention;

[0031] Figure 7 This is a BH curve diagram of JFE10JNX900 silicon steel sheet (0.1 mm) according to an embodiment of the present invention;

[0032] Figure 8 This is an information diagram of the remanence, coercive force, and square coefficient Hk / Hcj of N52UH magnetic steel in an embodiment of the present invention;

[0033] Fig. 9 Schematic diagram of electromagnetic simulation input conditions under 30,000 rpm power in an embodiment of the present invention;

[0034] Fig.10This is an electromagnetic simulation data diagram under 30000 rpm power in an embodiment of the present invention;

[0035] Fig.11 This is a cloud diagram of magnetic induction density at 30,000 rpm in an embodiment of the present invention;

[0036] Fig.12 This is a diagram of the magnetic induction intensity of each part under a power of 30,000 rpm in an embodiment of the present invention;

[0037] Fig.13 This is a loss distribution diagram obtained by simulation under 30,000 rpm power in an embodiment of the present invention;

[0038] Fig.14 This is a torque curve diagram obtained by simulation under 30000 rpm electric power in an embodiment of the present invention;

[0039] Fig.15 This is an efficiency MAP diagram obtained by simulation under 30,000 rpm power in an embodiment of the present invention;

[0040] Fig.16 This is a diagram of thermal simulation results at 30,000 rpm of electrical power in an embodiment of the present invention;

[0041] Figure 17-18 They are respectively a stress cloud diagram and a simulation result of the rotor strength simulation in an embodiment of the present invention;

[0042] Fig.19 This is a simulation result diagram of the cogging torque and torque ripple when the 30000 rpm electric power is turned on in the embodiment of the present invention;

[0043] Fig. 20 This is a 2D spectrum of the time-dominant stator radial harmonics of an embodiment of the present invention;

[0044] Fig.21 A Campbell sound pressure field spectrum diagram according to an embodiment of the present invention;

[0045] Fig. 22 It is a schematic diagram of stator radial stress data-space 1D of an embodiment of the present invention;

[0046] Fig.23 This is a radial wiring diagram of a stator according to an embodiment of the present invention;

[0047] Figure 24-25 They are respectively a phase current curve and a power generation voltage curve diagram of an embodiment of the present invention;

[0048] Fig.26 This is a stator linear wiring diagram of an embodiment of the present invention;

[0049] The numbers in the figure represent:

[0050] 100-30,000 rpm range extender generator for electric aircraft;

[0051] 1- stator, 11- stator core, 111- stator slot, 112- stator tooth, 113- insulating paper, 114- insulating paint, 12- winding; 2- rotor, 21- rotor core, 22- magnetic steel group; 3- cooling shell, 31- cooling channel; 4- inner retaining ring, 41- cooling cavity, 42- end cover. [Specific implementation method]

[0052] Embodiment 1:

[0053] Please refer to Figure 1-Figure 4 The present embodiment is a 30,000 rpm range extender generator 100 for an electric aircraft, which includes a stator 1, a rotor 2 disposed inside the stator 1, and a heat sink 3 disposed outside the stator 1.

[0054] The stator 1 includes a stator core 11 and a winding 12. The inner wall of the stator core 11 is provided with a plurality of stator slots 111 at equal angles along its own circumference, and a winding 12 is provided in each stator slot 111. A stator tooth 112 is formed between two adjacent stator slots 111. The outer diameter D1 of the stator core 11 is 262 mm, and the inner diameter D2 of the stator core 11 is 182 mm.

[0055] The rotor 2 includes a rotor core 21 and a magnetic steel group 22. The outer wall of the rotor core 21 is provided with a plurality of accommodating cavities (not shown) at equal angles along its own circumference, and each of the accommodating cavities is provided with a group of magnetic steel groups 22. The outer diameter D3 of the rotor core 21 is 177 mm, and the inner diameter D4 of the rotor core 21 is 138 mm.

[0056] The air gap width L1 between the stator 1 and the rotor 2 is 2.5 mm, that is, the distance between the outer wall of the magnetic steel group 22 and the inner wall of the stator core 11. The main cross-sectional shape of the stator slot 111 is rectangular, and a retracted notch is formed on the side close to the inner wall of the stator core 11. The retracted contour is a straight line, and its notch width L2=6 mm, the slot depth L3 of the stator slot 111 is 27 mm, and the inclination angle of the retracted contour, that is, the slot tip angle θ1=40°, the stator slot 111 is a parallel slot, and its parallel slot width L4=11 mm. The pole arc angle θ2=152°, the magnetic steel thickness L5=5.5 mm. The magnetic steel adopts 52UH neodymium iron boron magnetic steel, with a remanence of 1.46T and a maximum operating temperature of 180°C, and is inserted into the accommodating cavity by radial insertion.

[0057] The more slots there are in the stator slot 111, the lower the harmonic content of the motor will be, which can effectively reduce the additional loss, reduce the harmonic leakage reactance, and make the magnetic potential waveform closer to a sine wave, which is beneficial to increasing the motor torque. In addition, the total heat dissipation area of ​​the coil side in the slot is increased, which is beneficial to heat dissipation and reduces the temperature rise. The number of rotor slots should be designed to match the number of stator slots. If the slot matching is not properly selected, it may cause the motor to fail to start, vibrate and make noise, and generate additional losses and additional torque. In this embodiment, the motor adopts 18 slots and 10 poles. That is, the number of slots of the stator slot 111 on the stator core 11 is 18. The number of magnetic steel groups 22 on the outer wall of the rotor core 21 is 10 groups, forming 10 poles. Figure 5 The height of the magnetomotive force waveform of 18 slots and 10 poles is stacked up. Through the matching mode of 18 slots and 10 poles, the end circulation can be avoided and a higher winding coefficient can be achieved.

[0058] In this embodiment, each pole is composed of 20 magnetic steels. By using 20 segmented processing of the magnetic steel, the eddy current loss and heat generation of the magnetic steel during the operation of the motor can be effectively reduced. In this embodiment, the magnetic steel uses N52UH NdFeB magnetic steel. The remanence, coercive force, and square coefficient Hk / Hcj of N52UH NdFeB magnetic steel are as follows: Figure 8 As shown, from Figure 8 It can be seen that N52UH NdFeB magnet can be used for a long time in the range of 180℃, the square coefficient is greater than 0.95, and the remanence Br is 1.46T.

[0059] In this embodiment, the outer periphery of the rotor 2 is provided with a sheath made of carbon fiber, and the thickness of the carbon fiber sheath is 1.5 mm. During the high-speed rotation of the motor, the provided carbon fiber sheath can prevent the magnetic steel from flying out. Moreover, the carbon fiber sheath has ultra-high strength and rigidity, which can provide good protection for the rotor 2, and will not increase the dead weight of the motor, thus realizing a lightweight design; the carbon fiber sheath has a high thermal conductivity, which can quickly dissipate heat and avoid overheating. At the same time, the thermal expansion coefficient of the carbon fiber sheath is small, and will not be deformed due to temperature changes, thus ensuring the stable performance of the motor in various working environments.

[0060] To ensure sufficient starting torque, the current density cannot be too small, while too large a current density will increase the slip rate, increase rotor resistance loss, reduce efficiency, and increase heat generation. In this embodiment, the winding 12 is wound in the form of a centralized single winding, and is wound with a temperature-resistant grade of 240°C corona-resistant polyimide copper flat wire. The centralized winding is wound with 6 turns per wire. The centralized winding can effectively reduce the end height, thereby reducing the copper loss and heat generation when the motor is running.

[0061] The filling rate of the stator slot 111 is 89.06% (including insulating paper). If the slot filling rate is too large, the winding will not be able to go into the slot; if the slot filling rate is too small, the slot utilization rate is too low, which is not conducive to the heat dissipation of the winding. In this embodiment, the filling rate of the stator slot 111 is designed to be 89.06%, which, together with the subsequent design of the size of the stator slot 111, not only ensures the feasibility of winding copper flat wire, but also has good heat dissipation performance.

[0062] The insulating paper 113 in the stator slot 111 is DuPont Nomex T410 aramid insulating paper with a thickness of 0.25 mm. The gap between the winding 12 and the stator slot 111 is filled with insulating varnish 114 , and the insulating varnish 114 uses VX4201 unsaturated polyester imide resin as the filling material of the stator slot 111 .

[0063] The rotor 2 is subjected to a pole tilting treatment, specifically a five-stage pole tilting treatment, with angles of -1.714°, -0.857°, 0°, 0.857°, and 1.714°. By adopting a segmented pole tilting treatment with a set angle on the rotor, the torque pulsation and cogging torque of the motor are reduced, and the vibration and noise of the motor are also reduced.

[0064] In this embodiment, the stator core 11 and the rotor core 21 are made of laminated silicon steel sheets, wherein the stator core 11 is made of 0.1mm thick JFE10JNX900 silicon steel sheets, and the rotor core 21 is made of 0.25mm thick 25WY900 high yield strength silicon steel sheets. The core stacking height of the stator core 11 and the rotor core 21 is 50mm, and the stacking coefficient is 0.97. Figure 6-Figure 7 , Figure 6 The BH curve of 25WY900 high yield strength silicon steel sheet (0.25mm) reflects the relationship between the magnetic induction intensity and the magnetic field intensity of 25WY900 high yield strength silicon steel sheet during the magnetization process. It can be seen from the figure that the saturation point is 1.95T; Figure 7 The BH curve of JFE10JNX900 silicon steel sheet (0.1mm) reflects the relationship between the magnetic induction intensity and the magnetic field intensity of JFE10JNX900 silicon steel sheet during the magnetization process. It can be seen from the figure that the saturation point is greater than 2.1T (curve not extrapolated).

[0065] A cooling shell 3 is arranged on the periphery of the stator 1, and the cooling shell 3 is arranged around the periphery of the stator 1. A cooling channel 31 is formed inside the cooling shell 3. A first cooling medium, such as cooling water, circulates in the cooling channel 31. Other first cooling media can also be used according to actual conditions, which is not limited here.

[0066] An inner retaining ring 4 is provided on the inner side of the rotor 2, and a cooling cavity 41 is formed between the inner retaining ring 4 and the cooling shell 3 to enclose the stator 1 and the rotor 2. The upper and lower ends of the cooling cavity 41 are sealed by end covers 42. A second cooling medium, such as ATF cooling oil, circulates in the cooling cavity 41. Other second cooling media can also be used according to actual conditions, which is not limited here.

[0067] In order to verify that the motor designed in this embodiment has excellent performance, a thermal simulation test and an electromagnetic simulation test were performed on the motor, and the tests are as follows:

[0068] (1) Electromagnetic simulation under 30,000 rpm forwarding:

[0069] Input conditions for electromagnetic simulation: generating voltage 762.6V, generating current 400A (rms), maximum motor speed 30000rpm; electromagnetic simulation software is Ansys Motor-CAD, using Maxwell tensor method to simulate the motor electromagnetically, air gap segmentation number of layers is 5, scanning angle is 360°, electromagnetic wire, stator, rotor segmentation length is system default; electromagnetic performance of the motor under generating voltage 762.6V and generating current 400A is simulated. The lead angle is set to 40°, winding copper wire temperature is set to 175℃, magnetic steel is set to 155℃, shaft temperature is set to 105℃, maximum speed is 30000rpm, iron loss coefficient Ka is 2.2; electrical load, electric density, and thermal load are: 77.73A / mm, 18.02A / mm respectively. 2 、1400.67A 2 / mm 3 After thermal equilibrium, the maximum winding temperature is 180°C, the magnetic steel temperature is 78°C, and the simulation conditions are input as follows: Fig. 9 shown.

[0070] The electromagnetic simulation results under 30,000 rpm are as follows: Fig.10 As shown, the simulation results show that the minimum power generation torque is 108.01Nm, the maximum efficiency is 97.745%, and the total loss is 6601.5W.

[0071] The magnetic induction density cloud diagram under 30,000 rpm current is as follows Fig.11 As shown, the magnetic induction intensity of each part is Fig.12 As shown, the simulation results show that: the maximum magnetic induction intensity is located at the tooth part at this time, the maximum is 1.778T, the average magnetic induction intensity of the air gap is 0.6219T, and the maximum magnetic induction intensity of the air gap is 1.453T.

[0072] The loss distribution obtained by simulation under 30000 RT power supply is as follows Fig.13 shown.

[0073] The torque curve obtained by simulation under 30000 rpm is as follows: Fig.14 As shown, the simulation results show that the minimum torque required for 30,000 rpm power generation is 91.07 Nm, and the power generation efficiency is 97.745%.

[0074] The efficiency MAP obtained by simulation under 30,000 forward power supply is as follows: Fig.15 As shown, the simulation results of the efficiency MAP at peak power show that when the speed is in the range of 7000rpm to 30000rpm, the motor efficiency is greater than 97%.

[0075] (2) 30,000-transfer thermal simulation:

[0076] The inlet temperature of cooling water in cooling shell 3 is 55℃, the water flow is 30L / min, the inlet temperature of ATF oil for spray cooling of winding in cooling cavity 41 is 65℃, the ATF oil flow is 24L / min; the electric load, electric density and heat load are 77.73A / mm, 18.02A / mm respectively. 2 、1400.67A 2 / mm 3 After thermal balance, the maximum temperature of the winding is 180℃ and the magnetic steel is 78℃.

[0077] The thermal simulation results under 30000 forwards are as follows Fig.16 As shown, the simulation results show that: in steady state, the winding temperature is up to 180°C, the magnetic steel temperature is 78°C, the carbon fiber sheath temperature of the rotor 2 is 91°C, the casing temperature is about 71°C, and the stator core 11 tooth temperature is about 150°C.

[0078] (3) Rotor strength simulation:

[0079] The rotor strength simulation results are as follows: Figure 17-18 As shown, Fig.17 This is the stress cloud diagram of rotor strength simulation. Fig.18 This is the rotor strength simulation result. The results show that at 30,000 rpm, the rotor is far from reaching the yield point of 950 MPa of 25WY900 material, and the actual maximum stress is only 721 MPa.

[0080] (4)NVH performance test: The simulation results of cogging torque and torque ripple at 30,000 rpm are as follows: Fig.19 As shown, the simulation results show that with the five-segment rotor skew treatment, the torque pulsation is 2.242% and the cogging torque is only 0.034Nm.

[0081] (5) Time-dominated stator radial harmonic 2D spectrum, such as Fig. 20 As shown, from the harmonic 2D spectrum of the stator radial force, the peaks are round and smooth, avoiding the problem of howling when the motor is running.

[0082] (6) Campbell sound pressure field spectrum, such as Fig.21As shown in the figure, the results show: at the spatial orders -8, -2, 4, and 10, corresponding to frequencies of about 3800 to 6300 Hz, there are abnormal NVH conditions, corresponding to speeds above 45,000 rpm, there is abnormal noise, and there may be resonance. The motor generating speed is 30,000 rpm (corresponding to 2500 Hz), avoiding the resonance point.

[0083] (7) Stator radial stress data, such as Fig. 22 shown.

[0084] (8) Stator radial wiring diagram as shown Fig.23 As shown, in this embodiment, the wiring is performed in a manner of two three-phase electric parallel connections.

[0085] (9) The phase current curve and the generation voltage curve are as follows: Fig.24 , 25 As shown in the figure, it can be seen that at 30,000 revolutions, the phase current peak is 565.6A and the generated voltage peak is 762.6V.

[0086] (10) Stator linear wiring diagram as shown Fig.26 shown.

[0087] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A 30,000-rpm range extender generator for electric aircraft, comprising a stator and a rotor arranged inside the stator; the stator comprises a stator core and a winding, the inner wall of the stator core is provided with a plurality of stator slots at equal angles along its own circumference, and each of the stator slots is provided with the winding; the rotor comprises a rotor core and a magnetic steel group, the outer wall of the rotor core is provided with a plurality of accommodating cavities at equal angles along its own circumference, and each of the accommodating cavities is provided with a group of magnetic steel groups; characterized in that: The number of the stator slots is 18, and the number of the magnetic steel groups is 10, forming an 18-slot 10-pole matching structure; The winding adopts concentrated winding; The stator core has an outer diameter D1=262 mm and an inner diameter D2=182 mm; The outer diameter D3 of the rotor core is 177 mm, and the inner diameter D4 is 138 mm; The air gap between the stator and the rotor is L1=2.5 mm; The slot width L2 of the stator slot is 6 mm, the slot depth L3 is 27 mm, the slot tip angle θ1 is 40°, and the stator slot is a parallel slot with a parallel slot width L4 of 11 mm; The rotor adopts five-stage pole tilting treatment, and the pole tilting treatment angles are: -1.714°, -0.857°, 0°, 0.857°, and 1.714°.

2. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: A stator tooth is formed between two adjacent stator slots, and the air gap is formed between the inner wall of the stator tooth and the outer wall of the magnetic steel group.

3. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: The pole arc angle θ2 = 152°.

4. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: The group of magnetic steels forms one pole, and the one pole includes 20 magnetic steels.

5. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 4, characterized in that: The thickness of the magnetic steel in the magnetic steel group is L5=5.5 mm, and the magnetic steel is inserted into the accommodating cavity in a radial insertion manner.

6. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 4, characterized in that: The magnetic steel adopts 52UH NdFeB magnetic steel with a remanence of 1.46T and a maximum operating temperature of 180°C.

7. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: The winding is made of corona-resistant polyimide copper flat wire with a temperature resistance grade of 240° C., and a single wire is wound with 6 turns.

8. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: The filling rate of the stator slot is 89.06%.

9. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: Insulating paper is provided in the stator slot to isolate the inner wall of the stator slot from the winding; the insulating paper is DuPont Nomex T410 aramid insulating paper with a thickness of 0.25 mm; the gap of the winding in the stator slot is filled with insulating varnish, and the insulating varnish is VX4201 unsaturated polyester imide resin.

10. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: The stator core and the rotor core are formed by stacking silicon steel sheets. The stator core uses 0.1mm thick JFE10JNX900 silicon steel sheets, and the rotor core uses 0.25mm thick 25WY900 high yield strength silicon steel sheets. The core stacking height of the stator core and the rotor core is 50mm, and the stacking coefficient is 0.

97.

11. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 1, characterized in that: A cooling shell is arranged on the outer periphery of the stator, and a first cooling medium circulates in the cooling shell; an inner retaining ring is arranged on the inner side of the rotor, and a cooling cavity enclosing the stator and the rotor is formed between the inner retaining ring and the cooling shell, and the upper and lower ends of the cooling cavity are sealed by end covers; a second cooling medium circulates in the cooling cavity.

12. The 30,000 rpm range extender generator for electric aircraft as claimed in claim 4, characterized in that: The outer circumference of the rotor is provided with a sheath to prevent the magnetic steel from flying out, the sheath is made of carbon fiber, and the thickness of the carbon fiber sheath is 1.5 mm.

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