Pole-variable permanent magnet machine
By alternating high and low coercivity permanent magnets in the motor and using an electronic controller to adjust the magnetization direction, the problem of low efficiency in adjusting torque and rotation speed of electric motors is solved, and flexible gear ratio changes in the propulsion system of motor vehicles are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GM GLOBAL TECHNOLOGY OPERATIONS LLC
- Filing Date
- 2024-12-06
- Publication Date
- 2026-04-10
AI Technical Summary
Existing electric motors suffer from inefficiency and lack of flexibility in adjusting torque and rotational speed, especially in propulsion systems of motor vehicles, where it is difficult to achieve effective gear ratio changes.
A variable pole radial flux motor is adopted. By alternately arranging high coercivity and low coercivity permanent magnets in the rotor, and using an electronic controller to adjust the direct axis current to change the magnetization direction of the low coercivity magnets, the number of magnetic poles can be dynamically adjusted to achieve the regulation of torque and rotation speed.
It achieves efficient torque and speed regulation of the motor under different load conditions, and can dynamically change the gear ratio in motor vehicles, improving the system's flexibility and efficiency.
Smart Images
Figure CN121840948A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a machine with a variable pole internal permanent magnet. Background Technology
[0002] An electric motor is a machine that converts electrical energy into mechanical energy. Electric motors can be configured as either alternating current (AC) or direct current (DC). The operation of an electric motor is based on the electromagnetic interaction between the rotor's magnetic field and the stator's magnetic field. The torque of an electric motor is typically generated through a flux linkage between the electromagnetic fields of the rotor's magnetic poles and the stator's electromagnetic field.
[0003] Electric motors are generally classified into two types based on the direction of the magnetic field—axial flux motors and radial flux motors. Electric motors can be synchronous and brushless, using permanent magnets as the poles for field excitation. Brushless radial flux motors can be configured as internal permanent magnet (IPM) or surface-mount permanent magnet (SPM) machines. IPMs have permanent magnets embedded and distributed within the rotor core, while SPMs have permanent magnets arranged on the rotor surface. Summary of the Invention
[0004] One aspect of this disclosure is a variable-pole radial flux motor, comprising a stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface, and a rotor mounted within the stator and configured to rotate relative to the stator about a rotation axis. The rotor includes a rotor core defined by an outer surface of the rotor, the rotor core establishing an air gap between the rotor and the stator. The rotor also includes N poles, each pole having at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux. The N / 2 number of poles includes relatively high coercivity magnets resistant to changes in magnetization direction, and the N / 2 number of poles includes relatively low coercivity magnets having a variable magnetization direction. The poles with relatively high coercivity magnets and the poles with relatively low coercivity magnets are arranged in an alternating sequence around the rotor core. The magnetization direction of the relatively low coercivity magnets is via a direct-axis current (i) to the relatively low coercivity magnet. d The application of this technology changes the number of magnetic poles operating in the motor.
[0005] Another aspect of this disclosure is a torque regulation system, which includes a variable pole radial flux motor and an electronic controller configured to regulate the operation of the variable pole radial flux motor. The electronic controller is configured to transmit a direct-axis current (i) to a relatively low coercivity magnet. d The application of this technology changes the magnetization direction of relatively low coercivity magnets, thereby changing the number of magnetic poles in the motor.
[0006] Another aspect of this disclosure is a motorized vehicle employing a torque regulation system for vehicle (or "vehicle") propulsion. In this embodiment, the electronic controller is configured to generate an effective gear ratio change during propulsion by altering the number of magnetic poles in the motor.
[0007] The electronic controller can be configured to transmit a positive direct-axis current (i) to a relatively low coercivity magnet. d The application of this technology reverses the magnetization direction of a relatively low coercivity magnet from that of a relatively high coercivity magnet, thereby reducing the number of magnetic poles operating in the motor from N to N / 2.
[0008] The electronic controller can be configured to transmit a reverse direct-axis current (i) to a relatively low coercivity magnet. d The application of this technology returns the magnetization direction of relatively low coercivity magnets to the alignment with the magnetization direction of relatively high coercivity magnets, thereby increasing the number of magnetic poles operating in the motor from N / 2 to N.
[0009] The electronic controller can be configured to change the magnetization direction of a relatively low coercivity magnet based on a predetermined torque output from the motor.
[0010] The electronic controller can be configured to change the magnetization direction of a relatively low coercivity magnet based on a predetermined rotational speed of the motor.
[0011] The coercivity of each relatively high coercivity magnet can be greater than or equal to 1000 kA / m, and the coercivity of each relatively low coercivity magnet can be less than or equal to 520 kA / m.
[0012] The rotor core may include a plurality of adjacent rotor laminations arranged along the axis of rotation. In this embodiment, complete magnetization of each relatively low coercivity magnet can be achieved at a flux density less than the saturation flux density in the rotor laminations.
[0013] Magnetic poles with relatively high coercivity and magnetic poles with relatively low coercivity can be arranged in a spatially or dimensionally asymmetrical configuration.
[0014] Each magnetic pole may include multiple permanent magnets and is defined by a U-shape, characterized by a flat portion generated by at least one of the constituent permanent magnets.
[0015] In another embodiment, each magnetic pole may include a plurality of permanent magnets and is defined by a Δ shape having a flat portion arranged close to an air gap.
[0016] In another embodiment, each magnetic pole may include multiple permanent magnets and be defined by a V-shape.
[0017] The torque regulation system may additionally include a multi-phase inverter regulated by an electronic controller to generate a direct-axis current (i) of at least 1 millisecond. d Direct-axis current (i) d It can be greater than the peak current at the maximum output torque of the motor and up to 3 times it.
[0018] The present invention also discloses the following technical solutions:
[0019] Option 1. A torque regulation system, the torque regulation system comprising:
[0020] A variable pole radial flux motor, comprising:
[0021] A stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface; and
[0022] A rotor, mounted within the stator and configured to rotate relative to the stator about a rotation axis, wherein the rotor comprises:
[0023] A rotor core, defined by an outer surface of a rotor, establishes an air gap between the rotor and the stator;
[0024] N magnetic poles, each of which has at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux;
[0025] in:
[0026] The number of N / 2 magnetic poles comprises relatively high coercivity magnets that resist changes in magnetization direction;
[0027] The number of magnetic poles, N / 2 in number, comprises relatively low coercivity magnets with variable magnetization directions; and
[0028] The magnetic poles having the relatively high coercivity magnets and the magnetic poles having the relatively low coercivity magnets are arranged in an alternating sequence around the rotor core; and
[0029] An electronic controller configured to regulate the operation of the variable pole radial flux motor, and via a direct-axis current (i) to the relatively low coercivity magnet. d The application of this technology changes the magnetization direction of the relatively low coercivity magnet, thereby changing the number of magnetic poles operating in the motor.
[0030] Option 2. The torque regulation system according to Option 1, wherein the electronic controller is configured to transmit a positive direct-axis current (i) to the relatively low coercivity magnet. dThe application of this method reverses the magnetization direction of the relatively low coercivity magnet from that of the relatively high coercivity magnet, thereby reducing the number of magnetic poles operating in the motor from N to N / 2.
[0031] Option 3. The torque adjustment system according to Option 2, wherein the electronic controller is configured to transmit a reverse direct-axis current (i) to the relatively low coercivity magnet. d The application of this method returns the magnetization direction of the relatively low coercivity magnet to the alignment with the magnetization direction of the relatively high coercivity magnet, thereby increasing the number of magnetic poles operating in the motor from N / 2 to N.
[0032] Option 4. The torque adjustment system according to Option 1, wherein the electronic controller is configured to change the magnetization direction of the relatively low coercivity magnet based on a predetermined torque output of the motor.
[0033] Option 5. The torque adjustment system according to Option 1, wherein the electronic controller is configured to change the magnetization direction of the relatively low coercivity magnet based on a predetermined rotational speed of the motor.
[0034] Option 6. The torque adjustment system according to Option 1, wherein the coercivity of each relatively high coercivity magnet is greater than or equal to 1000 kA / m, and the coercivity of each relatively low coercivity magnet is less than or equal to 520 kA / m.
[0035] Option 7. The torque adjustment system according to Option 1, wherein:
[0036] The rotor core includes a plurality of adjacent rotor laminations arranged along the axis of rotation; and
[0037] The complete magnetization of the relatively low coercivity magnet is achieved at a flux density lower than that required for the rotor laminations to saturate.
[0038] Option 8. The variable pole radial flux motor according to Option 1, wherein the magnetic pole having the relatively high coercivity magnet and the magnetic pole having the relatively low coercivity magnet are asymmetrically configured.
[0039] Option 9. The torque adjustment system according to Option 1, wherein each magnetic pole comprises a plurality of permanent magnets and is defined by a U-shape, the U-shape being characterized by a flat portion generated by at least one of the constituent permanent magnets.
[0040] Option 10. The torque adjustment system according to Option 1, wherein each magnetic pole comprises a plurality of permanent magnets and is defined by a Δ shape having a flat portion arranged close to the air gap.
[0041] Option 11. A motor vehicle, the motor vehicle comprising:
[0042] A variable-pole radial flux motor, configured to generate torque and operable to provide an effective gear ratio change for propulsion of the motorized vehicle, the variable-pole radial flux motor comprising:
[0043] A stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface; and
[0044] A rotor, mounted within the stator and configured to rotate relative to the stator about a rotation axis, wherein the rotor comprises:
[0045] A rotor core, defined by an outer surface of a rotor, establishes an air gap between the rotor and the stator;
[0046] N magnetic poles, each of which has at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux;
[0047] in:
[0048] The number of N / 2 magnetic poles comprises relatively high coercivity magnets that resist changes in magnetization direction;
[0049] The number of magnetic poles, N / 2 in number, comprises relatively low coercivity magnets with variable magnetization directions; and
[0050] The magnetic poles having the relatively high coercivity magnets and the magnetic poles having the relatively low coercivity magnets are arranged in an alternating sequence around the rotor core; and
[0051] An electronic controller configured to regulate the operation of the variable pole radial flux motor, and via a direct-axis current (i) to the relatively low coercivity magnet. d The application of this technology alters the magnetization direction of the relatively low coercivity magnet, thereby changing the number of magnetic poles operating in the motor and producing the change in the effective gear ratio during propulsion.
[0052] Option 12. The motor vehicle according to Option 11, wherein the electronic controller is configured to transmit a positive direct-axis current (i) to the relatively low coercivity magnet. d The application of this method reverses the magnetization direction of the relatively low coercivity magnet from that of the relatively high coercivity magnet, thereby reducing the number of magnetic poles operating in the motor from N to N / 2.
[0053] Option 13. The motor vehicle according to Option 12, wherein the electronic controller is configured to transmit a reverse direct-axis current (i) to the relatively low coercivity magnet. d The application of this method returns the magnetization direction of the relatively low coercivity magnet to the alignment with the magnetization direction of the relatively high coercivity magnet, thereby increasing the number of magnetic poles operating in the motor from N / 2 to N.
[0054] Option 14. The motor vehicle according to Option 11, wherein the electronic controller is configured to change the magnetization direction of the relatively low coercivity magnet based on a predetermined torque output of the motor.
[0055] Option 15. The motor vehicle according to Option 11, wherein the electronic controller is configured to change the magnetization direction of the relatively low coercivity magnet based on a predetermined rotational speed of the motor.
[0056] Option 16. The motor vehicle according to Option 11, wherein the coercivity of each relatively high coercivity magnet is greater than or equal to 1000 kA / m, and the coercivity of each relatively low coercivity magnet is less than or equal to 520 kA / m.
[0057] Option 17. The motor vehicle according to Option 11, wherein:
[0058] The rotor core includes a plurality of adjacent rotor laminations arranged along the axis of rotation; and
[0059] The complete magnetization of the relatively low coercivity magnet is achieved at a flux density lower than that required for the rotor laminations to saturate.
[0060] Option 18. The motor vehicle according to Option 11, wherein the magnetic pole having the relatively high coercivity magnet and the magnetic pole having the relatively low coercivity magnet are in an asymmetrical configuration.
[0061] Option 19. The motor vehicle according to Option 11, wherein each magnetic pole comprises a plurality of permanent magnets and is defined by a U-shape, the U-shape being characterized by a flat portion generated by at least one of the constituent permanent magnets.
[0062] Option 20. A variable pole radial flux motor, the variable pole radial flux motor comprising:
[0063] A stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface; and
[0064] A rotor, mounted within the stator and configured to rotate relative to the stator about a rotation axis, wherein the rotor comprises:
[0065] A rotor core, defined by an outer surface of a rotor, establishes an air gap between the rotor and the stator;
[0066] N magnetic poles, each of which has at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux;
[0067] in:
[0068] The number of N / 2 magnetic poles comprises relatively high coercivity magnets that resist changes in magnetization direction;
[0069] The number of magnetic poles, N / 2 in number, comprises relatively low coercivity magnets with variable magnetization directions; and
[0070] The magnetic poles having the relatively high coercivity magnets and the magnetic poles having the relatively low coercivity magnets are arranged in an alternating sequence around the rotor core; and
[0071] via the direct-axis current (i) to the relatively low coercivity magnet d The application of this technology alters the magnetization direction of the relatively low coercivity magnet, which in turn changes the number of magnetic poles operating in the motor.
[0072] The foregoing features and advantages, as well as other features and advantages of this disclosure, will become apparent from the following detailed description of the embodiments and preferred modes described herein for carrying out the purposes of the disclosure, when taken in conjunction with the accompanying drawings and claims. Attached Figure Description
[0073] Figure 1 This is a schematic diagram of a motor vehicle according to the present disclosure, which employs a power system using a variable-pole radial flux motor that provides propulsion for the vehicle.
[0074] Figure 2 The components described herein are part of a torque regulation system. Figure 1 The diagram shows a schematic close-up partial cross-sectional perspective view of a variable pole radial flux motor.
[0075] Figure 3 According to embodiments of this disclosure Figure 2 The schematic front view of the variable pole radial flux motor shown in the figure depicts magnetic poles with alternating high coercivity magnets and low coercivity magnets arranged in a V-shape.
[0076] Figure 4 According to another embodiment of this disclosure Figure 2The schematic front view of the variable pole radial flux motor shown in the figure depicts alternating high coercivity magnets and low coercivity magnets arranged in a U-shape.
[0077] Figure 5 According to another embodiment of this disclosure Figure 2 The schematic front view of another embodiment of the variable pole radial flux motor shown in the figure depicts alternating high coercivity magnets and low coercivity magnets arranged in a Δ shape.
[0078] Figure 6 According to another embodiment of this disclosure Figure 2 The schematic front view of another embodiment of the variable pole radial flux motor shown in the figure depicts alternating high coercivity magnets and low coercivity magnets with an asymmetrical spoke arrangement, wherein the magnets in the alternating poles have different spacings.
[0079] Figure 7 According to another embodiment of this disclosure Figure 2 The schematic front view of another embodiment of the variable pole radial flux motor shown in the figure depicts alternating high coercivity magnets and low coercivity magnets with a symmetrical spoke arrangement, the magnets in the alternating poles having different sizes. Detailed Implementation
[0080] The embodiments of this disclosure as described herein are intended to be illustrative. Other embodiments may take various or alternative forms. Additionally, the drawings are generally schematic and do not need to be drawn to scale. Some features may be exaggerated or reduced to illustrate details of particular parts. Therefore, the details of the specific structures and functions disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to perform this disclosure in various ways.
[0081] Certain terms may be used for reference only in the following description and are therefore not intended to be limiting. For example, terms such as “above” and “below” refer to direction in the accompanying drawings with reference. Words such as “front,” “rear,” “front part,” “rear part,” “left,” “right,” “rear,” “side,” “upward,” “downward,” “top,” and “bottom” describe the orientation and / or position of a part or element within a consistent but arbitrary frame of reference, which is determined by reference to the text describing the part or element under discussion and the associated drawings. Furthermore, terms such as “first,” “second,” “third,” etc., may be used to describe individual parts. As defined by the appended claims, such terms may include the words specifically mentioned above, their derivatives, and words with similar meanings, and are used descriptively with reference to the drawings and do not constitute a limitation on the scope of this disclosure.
[0082] refer to Figure 1 The present invention depicts a motor vehicle 10 having a power system 12. The motor vehicle 10 may include, but is not limited to, commercial vehicles, engineering vehicles, passenger vehicles, aircraft, ships, trains, or the like. It is also contemplated that the motor vehicle 10 may be a mobile platform such as an aircraft, an all-terrain vehicle (ATV), a ship, a personal mobile device, a robot, or the like for performing the purposes of this disclosure. The power system 12 includes a motor depicted as an electric generator and configured to generate a first power source torque T1 (in...). Figure 1 The first power source 14 (as shown in the middle diagram) is used to propel the motor vehicle 10 relative to the road surface via driven wheels 16. The electric generator 14 is configured as a radial flux electric motor, the magnetic flux is generated perpendicular to the axis of rotation of the motor, and the air gap between the rotor and stator of the machine is arranged concentrically with the axis of rotation.
[0083] like Figure 1 As shown, the power system 12 may also include a second power source 20, such as an internal combustion engine configured to generate a second power source torque T2. Power sources 14 and 20 may work together to power the motor vehicle 10 and are operatively connected to the transmission assembly 22. The transmission assembly 22 may be configured to transmit the first and / or second power source torques T1, T2 to the final drive unit 24, which may in turn be connected to the driven wheels 16. The first power source 14 is an electric motor or electric motor, which may be mounted, for example, to the second power source 20, to the transmission assembly 22 (or incorporated into the transmission assembly 22), to the final drive unit 24, or as a separate component of the vehicle 10 structure. As shown, the motor vehicle 10 additionally includes a programmable electronic controller 26 configured to communicate via a high-voltage BUS 27 and control the power system 12 to generate a predetermined amount of power source torque (the sum of T1 and T2) and various other vehicle systems. The electronic controller 26 is mounted on the motor vehicle 10 and (operably in communication with the power sources 14 and 20) is a component of the torque regulation system 28. The motor vehicle 10 additionally includes an energy storage system 30, such as one or more batteries, configured to generate and store electrical energy for powering the power sources 14 and 20 and the electronic controller 26.
[0084] The electronic controller 26 may be a central processing unit (CPU) or powertrain control module (PCM) configured to receive data signals from various vehicle sensors and regulate the propulsion of the vehicle. The electronic controller 26 includes tangible and non-transient memory. The memory may be a recordable medium that participates in providing computer-readable data or processing instructions. Such media can take many forms, including but not limited to non-volatile and volatile media. Non-volatile media used by the electronic controller 26 may include, for example, optical discs or magnetic disks, and other persistent storage. The volatile media of the memory for each controller may include, for example, dynamic random access memory (DRAM) that can constitute main memory. Such instructions may be transmitted via one or more transmission media, including coaxial cables, copper wires, and optical fibers, including electrical wires, which may include system buses connected to the vehicle system.
[0085] The memory of the electronic controller 26 may also include floppy disks, hard disks, magnetic tapes, other magnetic media, CD-ROMs, DVDs, other optical media, etc. The electronic controller 26 may be equipped with a high-speed master clock, necessary analog-to-digital (A / D) and / or digital-to-analog (D / A) circuitry, input / output circuitry and devices (I / O), and appropriate signal conditioning and / or buffering circuitry. Algorithms required by or accessible to the electronic controller 26 (typically represented via digits 32) can be programmed in the controller, stored in memory, and executed automatically to provide the required functions, such as for operating the torque regulation system 28.
[0086] Figure 2 The overall cross-section of the electric motor 14 is shown, and it is configured as a variable-pole radial flux motor, which will be described in detail below. The electric motor 14 includes a rotatable fixed stator 34 having a generally cylindrical core 36 and winding slots 38. Also as... Figure 2 As illustrated in the diagram, the stator core 36 also has a radially inner stator core surface 36A. The electric motor 14 additionally includes a rotor 40 arranged on a shaft defining a rotation axis X and thus mounted for rotation within the stator 34. The stator 34 may include multi-phase AC windings or poles 38A arranged in winding slots 38, wherein the windings receive multi-phase AC from a power inverter (discussed below) to establish a rotating magnetic field that applies torque to the rotor 40. The stator windings 38A are generally contained within the winding slots 38, wherein the number of end turns of the winding extends beyond the limits of the cylindrical core 36 at axially opposed stator ends (first end 36-1 and second end 36-2).
[0087] The rotor 40 has a ferromagnetic rotor core 42. The rotor core 42 has axially opposed rotor core ends (first end 42-1 and second end 42-2) and is defined by a radially outer rotor surface 42A. An air gap 43 is also established between the stator 34 and its rotor outer surface 42A. Figure 2 (See diagram). The rotor core 40 may be made of a relatively soft magnetic material (such as laminated silicon steel or iron steel). The rotor 40 also includes N magnetic poles 44, each having at least one permanent magnet disposed in the rotor core 42 and configured to generate magnetic flux 46. In particular, the stacked rotor laminations 48 of the core 40 may include gaps forming an inner pocket 50 in which one or more permanent magnets are placed or embedded, the gaps collectively defining a particular magnetic pole 44. The variable pole radial flux motor 14 may be an internal permanent magnet (IPM) or surface-mount permanent magnet (SPM) synchronous machine, as understood by those skilled in the art.
[0088] like Figure 3 As illustrated, N / 2 number of magnetic poles 44 include relatively high coercivity magnets 52-1 that can withstand external magnetic fields without being demagnetized; each of these poles is identified by the number 44-1. Additionally, other N / 2 number of magnetic poles 44 include relatively low coercivity magnets 52-2 that will be demagnetized by similar external magnetic fields; each of these poles is identified by the number 44-2. As shown, magnetic poles 44-1 and 44-2 are arranged in an alternating sequence around rotor core 40. Coercivity is typically measured in oersted or amperes per meter (A / m) and is indicated by "H". C The term "52-1" indicates that the coercivity of each relatively high coercivity magnet can be greater than or equal to 1000 kA / m, such as for a strong neodymium magnet. The coercivity of each relatively low coercivity magnet can be less than or equal to 520 kA / m, such as for ferrite or ferrite nitride magnets.
[0089] Electronic controller 26 is configured to regulate the rotational speed and torque output of variable pole radial flux motor 14. Specifically, electronic controller 26 is programmed via a specific algorithm 32 to change the magnetization direction of the relatively low coercivity magnet 52-2. The magnetization direction of the relatively low coercivity magnet 52-2 is determined by the stator winding 38A via the direct-axis (or d-axis) current (i) to the low coercivity magnet 52-2. d The application of this change alters the number of magnetic poles operating in the motor 14. The variable pole radial flux motor 14 can be configured such that full magnetization of each relatively low coercivity magnet 52-2 is achieved at a flux density 46 less than that required for saturation of the rotor laminations 48. This flux density relationship between the low coercivity magnets 52-2 and the rotor laminations 48 is designed to promote saturation of the rotor core 40 with flux 46 during pole switching in the motor 14.
[0090] As understood, in a rotating electrical machine, the d-axis and the quadrature axis (or q-axis) are two orthogonal axial components representing the directions of magnetic flux, current, and inductance. The d-axis is positioned in the direction of the magnetic flux of the permanent magnet poles and is electrically separated from the q-axis by 90 degrees. Typically, when the d-axis current (i... d When the current (i) is positive, the stator current generates a magnetomotive force (MMF) around the air gap, which enhances the d-axis magnetic flux. On the other hand, if the d-axis stator current (i) is positive, the stator current generates a magnetomotive force (MMF) around the air gap, which enhances the d-axis magnetic flux. d The field weakening control is set to a negative value (known as field weakening control), which allows the machine to operate above its base speed. In conventional motors, field weakening control helps achieve constant power at high speeds.
[0091] The electronic controller 26 can be configured to transmit a positive d-axis current (i) to a relatively low coercivity magnet 52-2. d The application of this method reverses the magnetization direction of the relatively low coercivity magnet 52-2 from its alignment with the magnetization direction of the relatively high coercivity magnet 52-1. The positive d-axis current (i...) d The application is configured to reversibly demagnetize the relatively low coercivity magnet 52-2 and magnetically strengthen the relatively high coercivity magnet 52-1, thereby reducing the number of magnetic poles 44 operating in the motor 14 from N to N / 2 and generating an N / 2 pole mode. The electronic controller 26 can also be configured to transmit a reverse d-axis current (i) to the relatively low coercivity magnet 52-2. d The application of this technology aligns the magnetization direction of the relatively low coercivity magnet 52-2 with that of the relatively high coercivity magnet 52-1. The reverse d-axis current (i...) d The application configuration is to remagnetize the relatively low coercivity magnet 52-2 and re-establish the original magnetization of the relatively high coercivity magnet 52-1, thereby increasing the number of magnetic poles operating in the motor from N / 2 to N and generating an N-pole mode.
[0092] The electronic controller 26 can be configured to influence pole switching based on the operating point of the motor 14, i.e., changing the magnetization direction of the relatively low coercivity magnet 52-2. The operating point of the motor 14 can be determined in response to parameters calculated from data detected by appropriate vehicle sensors (not shown) and / or from usage experience. A specific pole switching point can be defined, for example, by a predetermined output torque T1 programmed into the electronic controller 26. Similarly, the electronic controller 26 can be configured to influence pole switching based on a predetermined rotational speed of the motor 14.
[0093] like Figure 3-5As illustrated in the diagram, each magnetic pole 44 may include multiple permanent magnets 52. Relatively high coercivity magnetic poles 44-1 and relatively low coercivity magnetic poles 44-2 may have a symmetrical arrangement 54. In other words, the individual arrangement and size of the constituent permanent magnets in each pole 44 may be substantially the same. Specifically, as... Figure 4 As illustrated in the diagram, magnetic pole 44 can be defined by permanent magnets 52 arranged in a U-shape 56. This U-shape 56 can be characterized by a flat portion 56-1, which is generated by at least one of the permanent magnets 52 arranged distal to or away from the air gap 43. Alternatively, as... Figure 5 As shown in the diagram, the magnetic pole 44 can be defined by a permanent magnet 52 arranged in a Δ shape 58, the Δ shape 58 having a flat portion 58-1 arranged close to or near the air gap 43.
[0094] In another embodiment, such as Figure 3 As illustrated in the diagram, magnetic pole 44 can be defined by permanent magnets 52 arranged in a V-shape 60, wherein the opening of the V is arranged close to the air gap 43. In individual embodiments, relatively high coercivity magnetic poles 44-1 and relatively low coercivity magnetic poles 44-2 can have a spatially or dimensionally asymmetrical configuration 62 (in... Figure 6 (as illustrated in the diagrams), where the positioning or size of the independent permanent magnet 52 in the corresponding alternating poles differs from that of a similar magnet in an adjacent pole. This asymmetric configuration 62 can be employed to reduce the excitation force (i.e., the required d-axis stator current (i...)). d The amplitude of the amplitude is used to facilitate pole switching and optimize torque fluctuations in motor 14. For example... Figure 6 and 7 As shown in the diagram, the permanent magnets 52 in the alternating magnetic poles 44 can be arranged in a spoke pattern.
[0095] The torque regulation system 28 may include a dedicated, adapted multi-phase power inverter 64. Figure 2 (as shown in the diagram), it has an integrated power module and a system for supplying direct-axis current (i). d A switch is used to switch the stator winding to 38A for pole switching. The direct-axis current (i) required for pole switching is... d The peak AC current at the maximum output torque T1 of motor 14 can be greater than, and up to, three times, that of the motor. The multi-phase power inverter 64 can be configured to generate a direct-axis current (i) of at least 1 millisecond. dAnd regulated by electronic controller 26. For example, the inverter power module can be adjusted for 1-millisecond transient pole-switching operation at thermal impedance that is at least 10 times lower than the impedance required for typical 10-microsecond electric motor operation. This reduced impedance will allow inverter 64 to generate the necessary direct-axis current (i) for at least 1 millisecond without exceeding the thermal limits of its power switches. d (Up to 3 times the peak current of the maximum output torque T1).
[0096] In general, the variable-pole radial flux motor 14 employs relatively high coercivity magnets in half of its rotor poles and relatively low coercivity magnets in the remaining poles. The high and low coercivity magnets are arranged in an alternating sequence around the rotor core, and the magnetization direction of the low coercivity magnets is changed via the application of a direct-axis current to alter the number of operating poles, thereby producing variations in the motor's maximum rotational speed and torque output. Additionally, the variable-pole radial flux motor 14 can use an asymmetrical configuration of its high and low coercivity magnets, wherein the alternating magnets are either significantly spaced or of different sizes to facilitate pole switching. When used to propel motorized vehicles and managed by an electronic controller, this configuration of the motor allows for effective gear ratio changes during vehicle operation.
[0097] The detailed description and accompanying drawings or figures are supportive and descriptive of this disclosure, but the scope of this disclosure is defined only by the claims. Although the best mode and other embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. Furthermore, the features of the embodiments illustrated in the drawings or the various embodiments mentioned in this description need not be understood as embodiments independent of each other. Rather, it is possible that each feature described in one of the examples of embodiments may be combined with one or more other desirable features from other embodiments, resulting in other embodiments not described in words or with reference to the drawings. Accordingly, such other embodiments fall within the framework of the appended claims.
Claims
1. A torque regulation system, the torque regulation system comprising: A variable pole radial flux motor, comprising: A stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface; and A rotor, mounted within the stator and configured to rotate relative to the stator about a rotation axis, wherein the rotor comprises: A rotor core, defined by an outer surface of a rotor, establishes an air gap between the rotor and the stator; N magnetic poles, each of which has at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux; in: The number of N / 2 magnetic poles comprises relatively high coercivity magnets that resist changes in magnetization direction; The number of magnetic poles, N / 2 in number, comprises relatively low coercivity magnets with variable magnetization directions; and The magnetic poles having the relatively high coercivity magnets and the magnetic poles having the relatively low coercivity magnets are arranged in an alternating sequence around the rotor core; and An electronic controller configured to regulate the operation of the variable pole radial flux motor, and via a direct-axis current (i) to the relatively low coercivity magnet. d The application of this technology changes the magnetization direction of the relatively low coercivity magnet, thereby changing the number of magnetic poles operating in the motor.
2. The torque adjustment system according to claim 1, wherein, The electronic controller is configured to receive a positive direct-axis current (i) via the relatively low coercivity magnet. d The application of this method reverses the magnetization direction of the relatively low coercivity magnet from that of the relatively high coercivity magnet, thereby reducing the number of magnetic poles operating in the motor from N to N / 2.
3. The torque adjustment system according to claim 2, wherein, The electronic controller is configured to receive a reverse direct-axis current (i) via the relatively low coercivity magnet. d The application of this method returns the magnetization direction of the relatively low coercivity magnet to the alignment with the magnetization direction of the relatively high coercivity magnet, thereby increasing the number of magnetic poles operating in the motor from N / 2 to N.
4. The torque adjustment system according to claim 1, wherein, The electronic controller is configured to change the magnetization direction of the relatively low coercivity magnet based on a predetermined torque output of the motor.
5. The torque adjustment system according to claim 1, wherein, The electronic controller is configured to change the magnetization direction of the relatively low coercivity magnet based on a predetermined rotational speed of the motor.
6. The torque adjustment system according to claim 1, wherein, The coercivity of each relatively high coercivity magnet is greater than or equal to 1000 kA / m, and the coercivity of each relatively low coercivity magnet is less than or equal to 520 kA / m.
7. The torque adjustment system according to claim 1, wherein: The rotor core includes a plurality of adjacent rotor laminations arranged along the axis of rotation; and The complete magnetization of the relatively low coercivity magnet is achieved at a flux density lower than that required for the rotor laminations to saturate.
8. The variable pole radial flux motor according to claim 1, wherein, The magnetic poles having the relatively high coercivity magnet and the magnetic poles having the relatively low coercivity magnet are arranged asymmetrically.
9. A motor vehicle, the motor vehicle comprising: A variable-pole radial flux motor, configured to generate torque and operable to provide an effective gear ratio change for propulsion of the motorized vehicle, the variable-pole radial flux motor comprising: A stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface; and A rotor, mounted within the stator and configured to rotate relative to the stator about a rotation axis, wherein the rotor comprises: A rotor core, defined by an outer surface of a rotor, establishes an air gap between the rotor and the stator; N magnetic poles, each of which has at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux; in: The number of N / 2 magnetic poles comprises relatively high coercivity magnets that resist changes in magnetization direction; The number of magnetic poles, N / 2 in number, comprises relatively low coercivity magnets with variable magnetization directions; and The magnetic poles having the relatively high coercivity magnets and the magnetic poles having the relatively low coercivity magnets are arranged in an alternating sequence around the rotor core; and An electronic controller configured to regulate the operation of the variable pole radial flux motor, and via a direct-axis current (i) to the relatively low coercivity magnet. d The application of this technology alters the magnetization direction of the relatively low coercivity magnet, thereby changing the number of magnetic poles operating in the motor and producing the change in the effective gear ratio during propulsion.
10. A variable pole radial flux motor, the variable pole radial flux motor comprising: A stator having a radially inner stator surface and stator windings disposed on the radially inner stator surface; as well as A rotor, mounted within the stator and configured to rotate relative to the stator about a rotation axis, wherein the rotor comprises: A rotor core, defined by an outer surface of a rotor, establishes an air gap between the rotor and the stator; N magnetic poles, each of which has at least one permanent magnet disposed in the rotor core and configured to generate magnetic flux; in: The number of N / 2 magnetic poles comprises relatively high coercivity magnets that resist changes in magnetization direction; The number of magnetic poles, N / 2 in number, comprises relatively low coercivity magnets with variable magnetization directions; and The magnetic poles having the relatively high coercivity magnets and the magnetic poles having the relatively low coercivity magnets are arranged in an alternating sequence around the rotor core; and via the direct-axis current (i) to the relatively low coercivity magnet d The application of this technology alters the magnetization direction of the relatively low coercivity magnet, which in turn changes the number of magnetic poles operating in the motor.