Axial-radial flux motor and control method, power control system and vehicle

Abstract

The application discloses an axial-radial coupled flux motor and a control method, a power control system and a vehicle. The control method comprises the following steps: at least one axial flux motor and at least one radial flux motor are coaxially arranged on a rotating shaft in a shell; an actual rotating speed of the rotating shaft is n, a working rotating speed boundary point n c and a transition rotating speed n t are obtained; when n c -n t , the axial flux motor is set to a main driving mode, the radial flux motor is set to a driving mode, an idle mode or a power generation mode to provide sufficient torque required by a load at the actual rotating speed, and the axial flux motor is always kept in a high-efficiency interval; when n c +n t , the radial flux motor is set to the main driving mode, the axial flux motor is set to the driving mode, the idle mode or the power generation mode to provide sufficient torque required by the load at the actual rotating speed, and the radial flux motor is always kept in the high-efficiency interval. The axial-radial coupled flux motor has small rotational inertia, strong power and certain fault tolerance.

Description

Technical Field

[0001] This invention belongs to the field of vehicle drive technology, specifically, it relates to a control method for an axially and radially coupled flux motor. This invention also relates to an axially and radially coupled flux motor controlled using the above-described control method, and a power control system and vehicle including the axially and radially coupled flux motor. Background Technology

[0002] The electric motor is the core component of an electric vehicle. Based on the vehicle's battery status and overall power requirements, the powertrain converts electrical energy from onboard energy storage or generation devices into mechanical energy. This energy is then transmitted to the drive wheels via a transmission system. During braking, some of the mechanical energy is converted back into electrical energy and fed back to the energy storage device. Currently, a commonly used integrated multi-motor drive structure integrates two radial flux motors within a housing to improve vehicle power; however, this design suffers from drawbacks such as large size and weight.

[0003] Furthermore, when an electric motor is used to drive a vehicle, the speed range varies greatly, resulting in significant torque variations. Existing multi-motor drive structures integrating two radial motors, in order to achieve higher overall efficiency, configure the high-efficiency range as the medium-speed range. Therefore, efficiency is low in the low-speed range, and insufficient driving torque is prone to occur in the high-speed range. To address the insufficient torque issue in the high-speed range, high-performance electric vehicles connect the motor output to a multi-speed gearbox for power output, such as the Porsche Taycan. Because the electric motor's speed is much higher than that of an internal combustion engine, such a matching multi-speed gearbox is very expensive and cannot be widely adopted.

[0004] To overcome the above-mentioned shortcomings and reduce the size and weight of integrated multi-motor systems, the most common approach is to integrate axial flux motors and / or radial flux motors. However, these systems generally suffer from complex manufacturing processes and magnetic circuits, high costs, and low control efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a control method for an axially and radially coupled flux motor to maintain high-efficiency motor operation.

[0006] Another object of the present invention is to provide an axially and radially coupled flux motor controlled by the above-described control method.

[0007] Another object of the present invention is to provide a power control system and a vehicle including the above-described axially and radially coupled flux motor.

[0008] To achieve the above objectives, the control method for the axially and radially coupled flux motor of the present invention includes the following steps:

[0009] At least one axial flux motor and at least one radial flux motor are separately and coaxially mounted on a rotating shaft inside the housing;

[0010] The actual rotational speed of the shaft is n; obtain the working speed dividing point n. c and transition speed n t ;

[0011] When n≤n c - n t When the axial flux motor is set to main drive mode and the radial flux motor is set to drive mode, idle mode or generator mode, it provides sufficient torque required by the load at the actual speed, so that the axial flux motor always stays in the high efficiency range.

[0012] When n≥n c + n t When the radial flux motor is set to main drive mode and the axial flux motor is set to drive mode, idle mode or generator mode, it provides sufficient torque required by the load at the actual speed, so that the radial flux motor always stays in the high efficiency range.

[0013] In the control method described above, the desired torque is T. ref When the working point (n, T) ref When the axial flux motor is in the first region of highest efficiency, the radial flux motor is set to idle mode.

[0014] The above control method, wherein, when the operating point (n, T) ref When the axial flux motor is in the second region where increasing torque can improve efficiency, the radial flux motor is set to power generation mode, and an appropriate amount of reverse torque is applied to the shaft.

[0015] The above control method, wherein, when the operating point (n, T) ref When the axial flux motor is in the third region where reducing torque can improve efficiency, the radial flux motor is set to drive mode, and an appropriate amount of positive torque is applied to the shaft.

[0016] The above control method, wherein, when the operating point (n, T) ref When the axial flux motor is in the fourth region where the maximum torque cannot be reached, the radial flux motor is set to drive mode to provide the remaining desired torque.

[0017] The above control method, wherein, when the operating point (n, T) ref When the radial flux motor is in the fifth region where it has the highest efficiency, the axial flux motor is set to idle mode.

[0018] The above control method, wherein, when the operating point (n, T) refWhen the radial flux motor is in the sixth region where increasing torque can improve efficiency, the axial flux motor is set to power generation mode, and an appropriate amount of reverse torque is applied to the shaft.

[0019] The above control method, wherein, when the operating point (n, T) ref When the radial flux motor is located in the seventh region where the torque efficiency remains basically unchanged, the axial flux motor is set to idle mode.

[0020] The above control method, wherein, when the operating point (n, T) ref When the radial flux motor is located in the eighth region where the maximum torque cannot be reached, the axial flux motor is set to drive mode to provide the remaining desired torque.

[0021] The above control method, wherein, when n∈(n c - n t , n c + n t When n gradually increases within this range, the torque provided by the axial flux motor gradually decreases, while the torque provided by the radial flux motor gradually increases, thus smoothly switching the power from the axial flux motor to the radial flux motor; when n gradually decreases within this range, the torque provided by the radial flux motor gradually decreases, while the torque provided by the axial flux motor gradually increases, thus smoothly switching the power from the radial flux motor to the axial flux motor.

[0022] The present invention also provides an axially and radially coupled flux motor controlled by the above-described control method for an axially and radially coupled flux motor.

[0023] The aforementioned axially and radially coupled flux motor further includes a planetary gear mechanism connected to the end of the rotating shaft.

[0024] The aforementioned axial-radial coupled flux motor, wherein the radial flux motor is one of a permanent magnet synchronous motor, an induction asynchronous motor, and a reluctance synchronous motor; and the axial flux motor is one of a permanent magnet synchronous motor and a reluctance synchronous motor.

[0025] The power control system of the present invention includes a controller and an axial-radial coupled flux motor as described above, wherein the controller independently controls the axial flux motor and the radial flux motor.

[0026] The vehicle of the present invention includes wheels, a vehicle body, and the aforementioned power control system connecting the vehicle body and the wheels.

[0027] The beneficial effects of this invention are that the axial-radial coupled flux motor and its control method combine the advantages of both axial and radial flux motors, resulting in low rotational inertia, high integration, and strong power. Furthermore, it can effectively recover braking energy, achieving high energy utilization efficiency and possessing a certain degree of fault tolerance.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Attached Figure Description

[0029] Figure 1A This is a cross-sectional view of an axially and radially coupled flux motor according to an embodiment of the present invention. The cross-section passes through the motor's rotation axis. The motor contains two axial flux motors and one radial flux motor, all of which are permanent magnet synchronous motors.

[0030] Figure 1B This is an exploded view of an axially and radially coupled flux motor according to an embodiment of the present invention. The explosion direction is the motor axis. The motor contains two axial flux motors and one radial flux motor, all of which are permanent magnet synchronous motors.

[0031] Figure 2A This is a cross-sectional view of an axially and radially coupled flux motor according to an embodiment of the present invention. The cross-section passes through the motor's rotation axis. The motor contains two axial flux motors and one radial flux motor, wherein the axial flux motors are permanent magnet synchronous motors and the radial flux motors are induction asynchronous motors.

[0032] Figure 2B This is an exploded view of an axially and radially coupled flux motor according to an embodiment of the present invention. The explosion direction is the motor axis. The motor contains two axial flux motors and one radial flux motor. The axial flux motors are permanent magnet synchronous motors, and the radial flux motors are induction asynchronous motors.

[0033] Figure 3A This is a cross-sectional view of an axially and radially coupled flux motor according to an embodiment of the present invention. The cross-section passes through the motor's rotation axis. The motor contains one axial flux motor and two radial flux motors, all of which are permanent magnet synchronous motors.

[0034] Figure 3B This is an exploded view of an axially and radially coupled flux motor according to an embodiment of the present invention. The explosion direction is the motor axis. The motor contains one axial flux motor and two radial flux motors, all of which are permanent magnet synchronous motors.

[0035] Figure 4 This is a cross-sectional view of an axially and radially coupled flux motor according to an embodiment of the present invention. The cross-section passes through the motor's rotation axis, and the motor contains a planetary gear mechanism.

[0036] Figure 5 This is a schematic diagram of a power control system in an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram of a power control system in an embodiment of the present invention, which includes an internal combustion engine.

[0038] Figure 7 This is a schematic diagram of a vehicle structure in an embodiment of the present invention.

[0039] Figure 8 An efficiency map of an embodiment of an axial flux motor;

[0040] Figure 9 An efficiency map of one embodiment of a radial flux motor;

[0041] Figure 10 This is a flowchart illustrating the control method of the axially and radially coupled flux motor of the present invention.

[0042] Among them, the attached reference numerals

[0043] 100 - Housing; 200 - First Axial Flux Motor

[0044] 210 - First axial flux motor stator; 211 - Axial stator back yoke

[0045] 212 - Axial stator winding; 220 - First axial flux motor rotor

[0046] 221-Axial rotor permanent magnet; 222-Axial rotor back yoke

[0047] 230-Axial air gap 300-Radial flux motor

[0048] 310 - Radial flux motor stator; 311 - Radial stator back yoke

[0049] 312 - Radial stator winding; 320 - Radial flux motor rotor

[0050] 321 - Radial rotor back yoke; 322 - Radial rotor permanent magnet

[0051] 330 - Radial air gap; 360 - Induction asynchronous motor rotor

[0052] 362-Excitation winding 400-Second axial flux motor

[0053] 410 - Stator of the second axial flux motor; 420 - Rotor of the second axial flux motor

[0054] 500-Shaft 600-First Radial Flux Motor

[0055] 700 - Axial flux motor; 800 - Second radial flux motor

[0056] 900 - Planetary gear mechanism; 910 - Sun gear

[0057] 920 - Planetary gear; 930 - External gear ring

[0058] 940-Planetary Carrier 1000-Axial and Radial Coupled Flux Motor

[0059] 2000-Controller 3000-Transmission

[0060] 4000 - Multi-function transmission; 5000 - Internal combustion engine

[0061] 6000-Power Control System; 7000-Transmission Mechanism

[0062] 7100 - Front axle driveshaft; 7200 - Front axle differential

[0063] 7300-Front Axle 8000-Wheel

[0064] 9000-Car Body

[0065] The first region where the axial flux motor achieves its highest efficiency.

[0066] The second region of 2-axial flux motors where increased torque improves efficiency.

[0067] The third region of 3-axial flux motors where reduced torque improves efficiency.

[0068] The fourth region where the maximum torque of the 4-axial flux motor cannot be reached.

[0069] 5- The fifth region where radial flux motors achieve the highest efficiency

[0070] 6-The sixth region of radial flux motors where increasing torque can improve efficiency.

[0071] 7-The seventh region of the radial flux motor where torque efficiency remains essentially unchanged.

[0072] The eighth region where the maximum torque of the 8-radial flux motor cannot be reached. Detailed Implementation

[0073] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the appended claims.

[0074] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. The same reference numerals in different drawings may identify the same or similar elements. Obviously, the embodiments described herein are only some embodiments of this invention, and not all embodiments.

[0075] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and appended claims of this invention, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0076] In this specification, references such as "an embodiment" or "a specific embodiment" mean that one or more embodiments of the invention include a particular feature, structure, or characteristic described in connection with that embodiment. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. In the various embodiments of the invention, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships. In this document, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0077] The axial-radial coupled flux motor and its control method of the present invention can be applied to various systems that include motors, such as passenger cars, commercial vehicles, special vehicles, ships, vessels, aircraft, etc.

[0078] The axial-radial coupled flux motor provided by the present invention includes a housing, a rotating shaft located within the housing, at least one axial flux motor, and at least one radial flux motor. The axial flux motor can generate axial flux, and the radial flux motor can generate radial flux. The axial flux motor, the radial flux motor, and the rotating shaft are arranged coaxially. The rotors of the axial flux motor and the radial flux motor are respectively fixedly connected to the rotating shaft. The stators of the axial flux motor and the radial flux motor are respectively fixedly connected to the housing. The housing provides axial and radial limiting for the rotating shaft.

[0079] The technical solution of the present invention will be described below with reference to the accompanying drawings, using an axially and radially coupled flux motor, a power control system, and a vehicle as examples.

[0080] Example 1

[0081] like Figure 1A and Figure 1B As shown, Figure 1A and Figure 1BThese are different views of an axially and radially coupled flux motor. In this embodiment, an axially and radially coupled flux motor includes a housing 100, a first axial flux motor 200, a second axial flux motor 400, a radial flux motor 300, and a rotating shaft 500. The first axial flux motor 200, the second axial flux motor 400, and the radial flux motor 300 are all arranged coaxially with the rotating shaft 500. Along the axial direction of the rotating shaft 500, they can be arranged in the following order: Arrangement 1: First axial flux motor stator 210, first axial flux motor rotor 220, radial flux motor 300, second axial flux motor rotor 420, second axial flux motor stator 410. Arrangement 2: First axial flux motor rotor 220, first axial flux motor stator 210, radial flux motor 300, second axial motor rotor 420, second axial flux motor stator 410. The third arrangement consists of a first axial flux motor rotor 220, a first axial flux motor stator 210, a radial flux motor 300, a second axial flux motor stator 410, and a second axial flux motor rotor 420. Figure 1A and Figure 1B Only the first arrangement order is shown in the image.

[0082] The first axial flux motor rotor 220, the second axial flux motor rotor 420, and the radial flux motor rotor 320 are fixedly connected to the shaft 500, and the connection method can be a tight fit, a keyed connection, or a spline connection. The first axial flux motor stator 210, the second axial flux motor stator 410, and the radial flux motor stator 310 are all fixedly connected to the housing 100, and the connection method can be a tight fit, bolt fixing, or riveting. The first axial flux motor stator 210 and the second axial flux motor stator 410 are connected to the shaft 500 through bearings to achieve radial support and relative rotation along the axial direction.

[0083] The first axial flux motor rotor 220 consists of an axial rotor permanent magnet 221 and an axial rotor back yoke 222. The axial rotor permanent magnet 221 is uniformly arranged and fixed to one side of the axial rotor back yoke 222 along the circumferential direction. The first axial flux motor stator 210 consists of an axial stator back yoke 211 that can be wound with wires and multiple axial stator windings 212 uniformly arranged along the circumferential direction. An axial air gap 230 exists between the first axial flux motor rotor 220 and the first axial flux motor stator 210. The magnetic flux generated by the axial rotor permanent magnet 221 enters the first axial flux motor stator 210 through the axial air gap 230, forming axial magnetic flux. This magnetic flux generates torque through interaction with the magnetic field generated by the axial stator windings 212, and this torque is ultimately transmitted to the rotating shaft 500 through the first axial flux motor rotor 220. The second axial flux motor 400 has the same structure and torque transmission method as the first axial flux motor 200.

[0084] The radial flux motor rotor 320 consists of radial rotor permanent magnets 322 and a radial rotor back yoke 321. The radial rotor permanent magnets 322 are evenly distributed along the circumference and are fixed to the surface of the radial rotor back yoke 321 or embedded inside the radial rotor back yoke 321. Figure 1A and Figure 1B Only the case where the radial rotor permanent magnet 322 is embedded inside the radial rotor back yoke 321 is shown. The radial flux motor stator 310 is arranged around the radial flux motor rotor 320 and consists of a radial stator back yoke 311 on which wires can be wound and multiple radial stator windings 312 evenly arranged in the circumferential direction. There is a radial air gap 330 between the radial motor rotor 320 and the radial motor stator 310. The magnetic flux generated by the radial rotor permanent magnet 322 enters the radial flux motor stator 310 through the radial air gap 330, forming radial flux. This flux generates torque by interacting with the magnetic field generated by the radial stator windings 312, and this torque is ultimately transmitted to the rotating shaft 500 through the radial flux motor rotor 320.

[0085] Furthermore, the axial rotor permanent magnet 221 and the radial rotor permanent magnet 322 are composed of high-performance permanent magnet materials, such as neodymium iron boron and rare earth cobalt, to achieve high magnetic flux density output.

[0086] Furthermore, the axial stator back yoke 211, axial rotor back yoke 222, radial stator back yoke 311, and radial rotor back yoke 321 are all or partly made of materials with good magnetic permeability and are processed into a configuration that is not easy to form eddy currents, such as silicon steel sheet laminations.

[0087] Example 2

[0088] like Figure 2A and Figure 2B As shown, Figure 2A and Figure 2B These are different views of a radially coupled flux motor along the same axis. The main difference between Embodiment 2 and Embodiment 1 is that the radial flux motor 300 is an induction asynchronous motor. The rotor 360 of the radial flux induction asynchronous motor consists of three or more sets of excitation windings 362. Magnetic flux is generated by passing alternating current through the excitation windings 362, and this flux interacts with the magnetic field generated by the radial stator windings 312 on the stator 310 of the radial flux motor to produce torque. The connection method between the rotor 360 of the radial flux induction asynchronous motor and the shaft 500 is the same as the connection method between the rotor 320 of the radial flux motor and the shaft 500 described in Embodiment 1.

[0089] Example 3

[0090] like Figure 3A and Figure 3B As shown, Figure 3A and Figure 3BThese are different views of the same axially and radially coupled flux motor. In this embodiment, an axially and radially coupled flux motor includes a housing 100, a first radial flux motor 600, a second radial flux motor 800, an axial flux motor 700, and a rotating shaft 500. The axial flux motor 700 and the radial flux motors (600 and 800) are all coaxially arranged with the rotating shaft 500. Along the axial direction of the rotating shaft, the arrangement sequence is: first radial flux motor 600, axial flux motor 700, and second radial flux motor 800. The connection method and operation mode of each motor with the rotating shaft 500 are the same as described in Embodiment 1.

[0091] The axial flux motor, radial flux motor, shaft, and housing components described in Examples 1 to 3 can all be manufactured individually and then assembled, effectively reducing production difficulty and costs. In the axial-radial coupled flux motors described in Examples 1 to 3, the windings of all internal motors are not interconnected, and the magnetic flux does not affect each other. Even if a single axial or radial flux motor fails, the remaining axial or radial flux motors can still operate normally, thus possessing a certain degree of fault tolerance. The axial-radial coupled flux motors described in Examples 1 to 3 also have the advantage of combining the advantages of axial and radial flux motors, resulting in low rotational inertia, high integration, and strong power.

[0092] Example 4

[0093] like Figure 4 As shown, in this embodiment, an axially and radially coupled flux motor, in addition to a housing 100, an axial flux motor, a radial flux motor, and a rotating shaft 500, also includes a planetary gear mechanism 900. The sun gears 910 of the axial flux motor, the radial flux motor, and the planetary gear mechanism 900 are all coaxially arranged with the rotating shaft 500, and the axial flux motor and the radial flux motor are arranged on the same side of the planetary gear mechanism along the axial direction. The axial flux motor and the radial flux motor can use the types and arrangements described in Embodiments 1, 2, and 3, or other types and arrangements. The rotating shaft 500 is fixedly connected to the sun gear 910 of the planetary gear mechanism 900, which can be achieved using a tight fit, a single key connection, or a spline connection. The outer gear ring 930 of the planetary gear mechanism 900 is fixedly connected to the housing 100, and the connection method can be a tight fit, bolt fixing, or riveting. The planet carrier 940 of the planetary gear mechanism 900 is connected to an external load.

[0094] The sun gear 910 of the planetary gear mechanism 900 rotates at the same speed as the shaft 500, and the planet carrier 940 rotates at the same speed as the planet gear 920, with the planet carrier 940 rotating in the same direction as the shaft 500. Through the reduction speed of the planetary gear mechanism 900, the motor torque is amplified by 3-10 times. The reduction ratio is calculated using the formula: Reduction ratio = (Number of teeth on the sun gear + Number of teeth on the planet gears) / Number of teeth on the planet gears.

[0095] The beneficial effect of this embodiment is that the planetary reduction mechanism and the motor are located in the same housing and share the fixing mechanism with the vehicle body, thus reducing the overall volume and weight, and reducing the distance of power transmission from the motor to the reducer and the loss during power transmission.

[0096] Example 5

[0097] like Figure 5 As shown, in one embodiment, the power control system includes a controller 2000, an axially and radially coupled flux motor 1000, and a transmission 3000. The controller 2000 includes at least two sets of drive units, capable of driving the axial flux motor and the radial flux motor independently. The controller 2000 independently controls the current frequency and / or amplitude and / or phase of the axial flux motor windings, and the current frequency and / or amplitude and / or phase of the radial flux motor windings, to change the drive torque or speed. The controller 2000 is connected to the axially and radially coupled flux motor 1000 via a cable for transmitting signals and drive current. The axially and radially coupled flux motor 1000 is mechanically driven by the transmission 3000, including but not limited to shaft drive, belt drive, and gear train drive. The transmission 3000 may have one or more reduction ratios. The transmission 3000 is connected to the mechanism to be driven, thereby transmitting the power generated by the axially and radially coupled flux motor 1000 to the mechanism.

[0098] Example 6

[0099] like Figure 6As shown, in one embodiment, the power control system includes an internal combustion engine 5000, a controller 2000, an axially and radially coupled flux motor 1000, and a multi-function transmission 4000. The connection between the controller 2000 and the axially and radially coupled flux motor 1000 is the same as described in Embodiment 5, and the connection between the axially and radially coupled flux motor 1000 and the multi-function transmission 4000 is the same as the connection between the axially and radially coupled flux motor 1000 and the transmission 3000 described in Embodiment 5. The internal combustion engine 5000 and the multi-function transmission 4000 are connected by mechanical transmission, including but not limited to shaft transmission, belt transmission, and pulley transmission. The difference between the multi-function transmission 4000 and the transmission 3000 in Embodiment 5 is that the multi-function transmission 4000, in addition to its gear-changing function, also has the function of switching power sources. The multi-function transmission 4000 is connected to the mechanism that needs to be driven, thereby transmitting the power generated by the axially and radially coupled flux motor 1000 and the internal combustion engine 5000 to the mechanism that needs to be driven.

[0100] Example 7

[0101] like Figure 7 As shown, in one embodiment, the vehicle includes a body 9000, wheels 8000, a transmission mechanism 7000, and a power control system 6000. The wheels 8000, transmission mechanism 7000, and power control system 6000 are mounted on the body 9000, and the power control system 6000 is connected to the wheels 8000 via the transmission mechanism 7000. The transmission mechanism 7000 transmits the mechanical energy generated by the power control system 6000 to the wheels 8000, thereby causing the vehicle to move.

[0102] Figure 7 In the illustrated embodiment, the transmission system consists of a front axle driveshaft 7100, a front axle differential 7200, and a front axle 7300. The power transmission path shown in the figure is: power control system 6000 — front axle driveshaft 7100 — front axle differential 7200 — front axle 7300 — wheel 8000.

[0103] Vehicles can also be used Figure 7 Power transmission path 2 (not shown): Power control system 6000 — rear axle drive shaft — rear axle differential — rear axle — wheel 8000.

[0104] Vehicles can also be used Figure 7 The third power transmission path (not shown in the diagram) is as follows: Power is transmitted from the power control system 6000 to the transfer case, then distributed to the front and rear axles, and finally transmitted to each wheel.

[0105] Vehicles can also be used Figure 7 The fourth power transmission path (not shown in the diagram) is where the power control system 6000 directly outputs power to a single wheel.

[0106] Example 8

[0107] In this embodiment, the operating modes of the above-mentioned axial and radial coupled flux motors are described below.

[0108] Based on the characteristics of the two types of motors, combined with Figure 10 The high-efficiency operating range of the axial flux motor is configured as the low-speed range, and the high-efficiency operating range of the radial flux motor is configured as the high-speed range. These two speed ranges need to be seamlessly connected.

[0109] In the low-speed range, the axial flux motor is always in drive mode. When the load torque is small, the radial flux motor is in generator mode, thereby increasing the efficiency by increasing the output torque of the axial flux motor. The generator power is adjusted by changing the number of coils connected in the generator closed loop in the radial flux motor, with the goal of maximizing the overall system efficiency at the current speed. When the load torque itself is sufficient to make the axial flux motor operate at its maximum efficiency, the radial flux motor is in idle mode. When the load torque exceeds the maximum output torque of the axial flux motor, the radial flux motor is in drive mode to increase the overall drive torque.

[0110] Within the high-speed range, the radial flux motor is always in drive mode. When the load torque is low, the axial flux motor is in generator mode, thereby increasing the output torque of the radial flux motor to improve efficiency. The generator power is adjusted by changing the number of coils connected in the generator closed loop in the axial flux motor, with the goal of maximizing the overall system efficiency at the current speed. When the load torque itself is sufficient to bring the radial flux motor to its maximum efficiency, the axial flux motor is in idle mode. When the load torque exceeds the maximum output torque of the radial flux motor, the axial flux motor is in drive mode to increase the overall drive torque.

[0111] When switching between two working zones, the motor control algorithm achieves a smooth transition through delay, interpolation, and other methods.

[0112] The method for switching the motor between drive, idling, and power generation modes can employ existing technologies.

[0113] The overall efficiency of the system = (driving power + generating power) / power consumption.

[0114] The beneficial effect of this implementation is that the axial flux motor or radial flux motor in the drive mode always operates in the high-efficiency range, and the other axial flux motor or radial flux motor switches between drive, idle and power generation modes in a timely manner. This not only allows for timely energy recovery, but also timely replenishment of output torque. Therefore, in the working mode of this embodiment, the axial and radial coupled flux motor not only has high energy efficiency, but also strong driving capability.

[0115] In detail, axial motors and radial motors have different efficiency maps. Figure 8 and Figure 9 Efficiency maps of typical axial flux motors and radial flux motors suitable for electric vehicles are shown. Due to their different constructions, axial flux motors tend to achieve high efficiency at lower speeds, while radial flux motors tend to achieve high efficiency at higher speeds. Figure 8 As shown, 500-3000 RPM is the highest efficiency speed range for this axial flux motor, and 20-80 Nm is the highest efficiency torque range; Figure 9 As shown, the highest efficiency speed range for this radial flux motor is 2000-8000 RPM, and the highest efficiency torque range is 70-250 Nm.

[0116] In the low-speed range, the axial flux motor is always in the main drive mode, while the radial flux motor works in coordination by switching operating modes. In the high-speed range, the radial flux motor is always in the main drive mode, while the axial flux motor works in coordination by switching operating modes. When the main drive motor deviates from its high-efficiency range, the output torque of the main drive motor is adjusted by coordinating different operating modes of the other motor, such as idling, driving, and generating, so that the main drive motor operates in a higher-efficiency range, maximizing the overall efficiency of the axial and radial coupled flux motors, and ensuring sufficient torque output.

[0117] The efficiency of a motor is represented by contour lines on an efficiency map. As the operating point moves away from the region of highest efficiency, the motor's efficiency gradually decreases. For example... Figure 8 and Figure 9 In the illustrated embodiment, for an axially and radially coupled flux motor composed of the axial flux motor and the radial flux motor, the operating speed dividing point n can be defined. c Set to 2500 rpm. Furthermore, set (n... c - n t ,n c + n t The main drive motor switches over a transition range. In this case, the transition speed n t =500rmp.

[0118] Assume that the actual speed of the motor during operation is n (in rpm), and the desired torque is T. ref (The unit is Nm), therefore the coordinates of the operating point on the efficiency map are (n, T) ref ).

[0119] When n≤n c - n t At this time, the axial flux motor is in the main drive mode.

[0120] Set the working point (n, T) ref Placed in Figure 8 The efficiency map of the axial flux motor is shown.

[0121] When the working point (n, T) ref When the axial flux motor is located in region 1 of the figure (i.e., the first region where the axial flux motor has the highest efficiency), it indicates that the axial flux motor is in the state of highest efficiency. At this time, the winding of the radial flux motor is disconnected from the external circuit, and the rotor of the radial flux motor is in the state of idling following the shaft.

[0122] When the working point (n, T) ref When the system is located in region 2 of the diagram (i.e., the second region where increasing the torque of the axial flux motor can improve efficiency), the axial flux motor is not at its highest efficiency at this speed when operating alone due to the relatively small desired torque. In this case, the radial flux motor is switched to generator mode, applying a reverse torque to the shaft. To ensure the shaft can output the desired torque, the axial flux motor will increase its torque, thereby improving its efficiency. In this operating mode, the overall system efficiency is maximized by adjusting the generator power of the radial flux motor.

[0123] When the working point (n, T) ref When the axial flux motor is located in region 3 of the diagram (i.e., the third region where reducing torque improves efficiency), it indicates that the axial flux motor is not operating at its highest efficiency at that speed when working alone due to the large desired torque. In this case, the radial flux motor is switched to drive mode, applying an appropriate amount of positive torque to the shaft. To ensure the shaft can output the desired torque, the axial flux motor will reduce its torque, thereby improving its efficiency. In this operating mode, by adjusting the supplementary torque provided by the radial flux motor, the overall system efficiency is maximized.

[0124] When the working point (n, T) ref When the value is located in region 4 of the figure (i.e., the fourth region where the maximum torque of the axial flux motor cannot be reached), it indicates that the axial flux motor alone is insufficient to provide the desired torque at this speed. At this time, the axial flux motor provides the maximum torque it can provide at this speed, and the radial flux motor is in drive mode and provides the remaining desired torque.

[0125] When n≥n c + n t At this time, the radial flux motor is in the main drive mode.

[0126] Set the working point (n, T) ref Placed in Figure 9 The efficiency map of the radial flux motor is shown.

[0127] When the working point (n, T) refWhen the radial flux motor is located in region 5 (the fifth region where the radial flux motor has the highest efficiency), it indicates that the radial flux motor is in the highest efficiency state. At this time, the winding of the axial flux motor is disconnected from the external circuit, and the rotor of the axial flux motor is in the state of free rotation following the shaft.

[0128] When the working point (n, T) ref When the radial flux motor is located in region 6 of the diagram (i.e., the sixth region where increasing the torque of the radial flux motor improves efficiency), it indicates that the radial flux motor is not operating at its highest efficiency at that speed due to the relatively small desired torque. In this case, the axial flux motor is switched to generator mode, applying a reverse torque to the shaft. To ensure the shaft can output the desired torque, the radial flux motor will also increase its torque, thereby improving its efficiency. In this operating mode, the overall system efficiency is maximized by adjusting the generator power of the axial flux motor.

[0129] When the working point (n, T) ref When the radial flux motor is located in region 7 of the figure (i.e., the seventh region where the torque efficiency of the radial flux motor remains basically unchanged), it indicates that the radial flux motor is in the highest efficiency state at that speed. At this time, the axial flux motor winding is disconnected from the external circuit, and the axial flux motor rotor is in the state of idling following the shaft.

[0130] When the working point (n, T) ref When the value is located in region 8 of the figure (i.e., the eighth region where the maximum torque of the radial flux motor cannot be reached), it indicates that the radial flux motor alone is insufficient to provide the desired torque at this speed. At this time, the radial flux motor provides the maximum torque it can provide at this speed, and the axial flux motor is in drive mode and provides the remaining desired torque.

[0131] When n∈(n c - n t , n c + n t When the rotational speed gradually increases within this range, the torque provided by the axial flux motor gradually decreases, while the torque provided by the radial flux motor gradually increases, thus smoothly switching the power from the axial flux motor to the radial flux motor. Conversely, when the rotational speed gradually decreases within this range, the torque provided by the radial flux motor gradually decreases, while the torque provided by the axial flux motor gradually increases, again smoothly switching the power from the radial flux motor to the axial flux motor. Power is not interrupted during this switching process.

[0132] The desired torque can come from the driver's operation; if the accelerator is pressed, it will give the controller a positive desired torque, and the deeper the accelerator is pressed, the greater the desired torque. It can also come from the upper-level controller of the autonomous / semi-autonomous vehicle.

[0133] The motor controller controls the direct-axis current Id and quadrature-axis current Iq output to the motor, using different amplitudes and ratios of the two to track the desired torque.

[0134] Vector control algorithms can be used to control the rotational speed and direction of the magnetic field by adjusting the direction and magnitude of the winding current according to the rotor speed, thereby adjusting the power generation and reverse torque, and achieving power generation in different rotation directions.

[0135] The overall system efficiency is calculated as (driving power + generating power) / power consumption.

[0136] Furthermore, the parameters of the control method can be calibrated at the factory, eliminating the need for user calibration. For motor systems with multiple axial flux motors and multiple radial flux motors, the aforementioned control modes can be achieved by controlling one or more of them.

[0137] Example 9

[0138] In this embodiment, the operating mode of an axially and radially coupled flux motor is described below.

[0139] When the vehicle is braking, one or more of the axial and radial flux motors in the axial-radial coupled flux motors are controlled to operate in energy recovery mode according to the braking force required. When the braking force demand cannot be met even when all axial and radial flux motors are in maximum energy recovery mode, the vehicle brakes are activated. The brakes only need to provide the total braking force required by the vehicle minus the braking force provided by the motors. The beneficial effect of this embodiment is that while the motors provide braking, they recover mechanical energy into electrical energy, extending the vehicle's range and reducing wear on the vehicle brakes.

[0140] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A control method for an axially and radially coupled flux motor, characterized in that, Includes the following steps: At least one axial flux motor and at least one radial flux motor are separately and coaxially mounted on a rotating shaft inside the housing; The actual rotational speed of the shaft is n; obtain the working speed dividing point n. c and transition speed n t ; When n≤n c - n t When the axial flux motor is set to main drive mode and the radial flux motor is set to drive mode, idle mode or generator mode, it provides sufficient torque required by the load at the actual speed, so that the axial flux motor always stays in the high efficiency range. When n≥n c + n t When the radial flux motor is set to main drive mode and the axial flux motor is set to drive mode, idle mode or generator mode, it provides sufficient torque required by the load at the actual speed, so that the radial flux motor always stays in the high efficiency range.

2. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the axial flux motor is in the first region of highest efficiency, the radial flux motor is set to idle mode.

3. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the axial flux motor is in the second region where increasing torque can improve efficiency, the radial flux motor is set to power generation mode, and an appropriate amount of reverse torque is applied to the shaft.

4. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the axial flux motor is in the third region where reducing torque can improve efficiency, the radial flux motor is set to drive mode, and an appropriate amount of positive torque is applied to the shaft.

5. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the axial flux motor is in the fourth region where the maximum torque cannot be reached, the radial flux motor is set to drive mode to provide the remaining desired torque.

6. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the radial flux motor is in the fifth region where it has the highest efficiency, the axial flux motor is set to idle mode.

7. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the radial flux motor is in the sixth region where increasing torque can improve efficiency, the axial flux motor is set to power generation mode, and an appropriate amount of reverse torque is applied to the shaft.

8. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the radial flux motor is located in the seventh region where the torque efficiency remains basically unchanged, the axial flux motor is set to idle mode.

9. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, The desired torque is T ref When the working point (n, T) ref When the radial flux motor is located in the eighth region where the maximum torque cannot be reached, the axial flux motor is set to drive mode to provide the remaining desired torque.

10. The control method for an axially and radially coupled flux motor according to claim 1, characterized in that, When n∈(n c -n t , n c + n t When n gradually increases within this range, the torque provided by the axial flux motor gradually decreases, while the torque provided by the radial flux motor gradually increases, so as to smoothly switch the power from the axial flux motor to the radial flux motor; when n gradually decreases within this range, the torque provided by the radial flux motor gradually decreases, while the torque provided by the axial flux motor gradually increases, so as to smoothly switch the power from the radial flux motor to the axial flux motor.

11. An axially and radially coupled flux motor controlled by the control method of the axially and radially coupled flux motor according to any one of claims 1 to 10.

12. The axially and radially coupled flux motor according to claim 11, characterized in that, It also includes a planetary gear mechanism connected to the end of the shaft.

13. The axially and radially coupled flux motor according to claim 11, characterized in that, The radial flux motor is one of a permanent magnet synchronous motor, an induction asynchronous motor, or a reluctance synchronous motor; the axial flux motor is one of a permanent magnet synchronous motor or a reluctance synchronous motor.

14. A power control system, characterized in that, It includes a controller and an axial-radial coupled flux motor as described in any one of claims 11-13, wherein the controller independently controls the axial flux motor and the radial flux motor.

15. A vehicle comprising wheels and a vehicle body, characterized in that, It also includes the power control system of claim 14 that connects the vehicle body and the wheels.

Images