Spoke type permanent magnet synchronous motor and magnetizing device thereof

Abstract

The present application discloses a Spoke-type permanent magnet synchronous motor and its magnetizing device. The motor comprises a stator and a rotor, wherein the rotor comprises a rotor core, permanent magnets, a support structure, a spacer, and an additional coil. The rotor core comprises a plurality of core units, wherein the permanent magnets are arranged in the gap between two adjacent core units, the support structure is arranged in the space surrounded by the rotor core, the spacer is connected between the support structure and the core units, and the additional coil is wound around the spacer. The additional coil has a reuse end, a magnetizing end, and a heating end. The reuse end and the magnetizing end are the head end and the tail end of the additional coil, respectively, and the heating end is located between the reuse end and the magnetizing end. When the reuse end and the heating end are connected to the magnetizing device, the additional coil can heat the permanent magnet under the action of the magnetizing device. When the reuse end and the magnetizing end are connected to the magnetizing device, the additional coil can magnetize the permanent magnet under the action of the magnetizing device. Through the above arrangement, the magnetizing efficiency of the permanent magnet synchronous motor is improved.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a Spoke-type permanent magnet synchronous motor and a magnetizing device thereof. Background Art

[0002] A Spoke-type permanent magnet synchronous motor consists of a rotor and a stator. The stator houses an armature winding, while the rotor comprises a rotor core and permanent magnets embedded within the core. The permanent magnets are arranged within the rotor core in a pattern similar to wheel spokes, directing the rotor's magnetic field lines radially. A notable feature of the Spoke-type permanent magnet synchronous motor is that the permanent magnets of two adjacent poles contribute magnetic flux to the air gap. This increases the air gap flux density, torque density, and material utilization. Due to its high efficiency, high power density, and ability to meet low-speed operation requirements, it is gradually replacing conventional brushed DC motors.

[0003] In existing technology, to assemble a rotor and stator, the rotor must first be magnetized. Once magnetization is complete, the rotor is installed within the stator. However, this assembly method creates electromagnetic forces between the permanent magnets and other motor components, hindering rotor assembly. This is particularly true during the assembly of large, spoke-type permanent magnet synchronous motors, where electromagnetic forces between the rotor and stator significantly increase the difficulty of rotor assembly.

[0004] Considering a post-assembly magnetization process where the motor is assembled first and then the permanent magnets are magnetized, if additional coils are placed around the rotor permanent magnets, the non-magnetized permanent magnets can be combined with the rotor core to form the rotor. The rotor is then installed in the stator, and the additional coils are energized, so that the magnetic field generated by the additional coil current magnetizes the rotor permanent magnets. However, because the permanent magnets of a Spoke-type permanent magnet synchronous motor are distributed in a spoke-like pattern on the rotor, the structure between adjacent permanent magnets is compact, making it difficult to place additional coils around the permanent magnets. Furthermore, for large Spoke-type permanent magnet synchronous motors, the magnetic field strength required to magnetize the permanent magnets is relatively high, and conventional magnetizing devices cannot meet the magnetization requirements of the permanent magnets, which may lead to the problem of permanent magnet magnetization not being saturated. Summary of the Invention

[0005] In order to address the deficiencies of the prior art, the purpose of this application is to provide a Spoke-type permanent magnet synchronous motor and a magnetizing device thereof, which can improve the magnetizing efficiency of the permanent magnet while ensuring the performance of the motor.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a Spoke-type permanent magnet synchronous motor, which includes a stator and a rotor, the rotor being arranged in a space surrounded by the stator and capable of rotating relative to the stator around its rotation axis; the rotor including a rotor core, a permanent magnet, a support structure, a pad and an additional coil, the rotor core including a plurality of core units, the plurality of core units being arranged at intervals around the rotation axis, the permanent magnet being arranged in the gap between two adjacent core units, the support structure being arranged in the space surrounded by the rotor core, the pad being connected between the support structure and the core units, each pad being connected to a core unit, the additional coil being wound around the pad, the additional coil having a reuse end, a magnetizing end and a heating end, the reuse end and the magnetizing end being the head end and the tail end of the additional coil respectively, and the heating end being located between the reuse end and the magnetizing end; the additional coil being capable of being connected to a magnetizing device, and when the reuse end and the heating end are connected to the magnetizing device, the additional coil being capable of heating the permanent magnet under the action of the magnetizing device; when the reuse end and the magnetizing end are connected to the magnetizing device, the additional coil being capable of magnetizing the permanent magnet under the action of the magnetizing device.

[0008] In some possible implementations, N consecutive additional coils can be interconnected to form an additional winding, which leads to a multiplexing end, a magnetizing end and a heating end, where N is a natural number greater than or equal to 2; when the multiplexing end and the heating end of the additional winding are connected to the magnetizing device, the additional winding is used to receive the alternating current generated by the magnetizing device, and the permanent magnet generates an alternating magnetic field under the action of the alternating current flowing through the additional winding, and the permanent magnet is eddy current heated under the alternating magnetic field.

[0009] In some possible implementations, M continuous permanent magnets can be divided into a magnetization group. When magnetizing the magnetization group, the number of permanent magnets in the magnetization group and the number of additional coils constituting the additional winding satisfy the following relationship: NM=1;

[0010] Where N represents the number of additional coils constituting the additional winding, and M represents the number of permanent magnets.

[0011] In some possible implementations, the pad includes a first part and a second part, the first part is pressed against the iron core unit, and the second part is pressed against the supporting structure, the additional coil includes a first part coil and a second part coil that are connected, the first part coil is wound on the surface of the first part, and the second part coil is wound on the surface of the second part, the multiplexing end is connected to the first part coil and connected to the head end of the first part coil; the heating end is connected to the first part coil and connected to the tail end of the first part coil; the magnetizing end is connected to the second part coil.

[0012] In some possible implementations, when viewed along the extension direction of the rotation axis, the spacer is T-shaped, and the spacer is at least partially located between the additional coil and the permanent magnet.

[0013] In some possible implementations, when viewed along the radial direction of the rotor, the additional coil between two adjacent spacers overlaps with the permanent magnet.

[0014] In the second aspect, the present application also provides a magnetizing device, which is applied to any one of the Spoke-type permanent magnet synchronous motors in the first aspect. The magnetizing device includes a charging circuit, a heating energy storage circuit, a magnetizing energy storage circuit and a discharge circuit. The charging circuit is used to generate current. The heating energy storage circuit is connected to the charging circuit and is used to receive the current generated by the self-charging circuit. The magnetizing energy storage circuit is connected to the charging circuit and is used to receive the current generated by the self-charging circuit. The magnetizing energy storage circuit is connected to the heating energy storage circuit in parallel. The discharge circuit is connected to the heating energy storage circuit and the magnetizing energy storage circuit. The discharge circuit can be connected to an additional coil. The discharge circuit is used to control the heating energy storage circuit and the additional coil to be turned on, and to form an alternating current in the additional coil to perform eddy current heating on the permanent magnet corresponding to the additional coil, or to control the magnetizing energy storage circuit and the additional coil to be turned on to magnetize the permanent magnet.

[0015] In some possible implementations, the heating energy storage circuit includes a first energy storage capacitor that provides current flowing through the additional coil when eddy current heating is performed on the permanent magnet; and the magnetizing energy storage circuit includes a second energy storage capacitor that provides current flowing through the additional coil when magnetizing the permanent magnet. The capacity of the first energy storage capacitor is greater than that of the second energy storage capacitor, and the charging voltage amplitude of the first energy storage capacitor is lower than the charging voltage amplitude of the second energy storage capacitor.

[0016] In some possible implementations, the discharge circuit includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube. The first end of the first switching tube is coupled to the first end of the third switching tube, and the first end of the first switching tube is also coupled to the connection node of the heating energy storage circuit and the magnetizing energy storage circuit; the second end of the second switching tube is coupled to the second end of the fourth switching tube, and the second end of the second switching tube is also coupled to the connection node of the heating energy storage circuit and the magnetizing energy storage circuit; the second end of the first switching tube is coupled to the first end of the second switching tube, and the second end of the third switching tube is coupled to the first end of the fourth switching tube; wherein the second end of the first switching tube and the second end of the third switching tube are used to connect to an additional coil.

[0017] During the assembly process of the Spoke-type permanent magnet synchronous motor provided in the present application, the non-magnetic permanent magnet can be first combined with the rotor core, and then the rotor can be assembled into the space formed by the stator to avoid the electromagnetic force between the permanent magnet and other motor components affecting the rotor assembly. By winding an additional coil on the pad and connecting it to an external magnetizing device, before magnetizing the permanent magnet, the current generated by the magnetizing device is received by the reuse end and the heating end of the additional coil to heat the permanent magnet, and the current generated by the magnetizing device is received by the reuse end and the magnetizing end of the additional coil to magnetize the heated permanent magnet. On the one hand, the difficulty of combining the rotor and the stator is reduced, and on the other hand, the magnetization efficiency of the permanent magnet is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a partial structural diagram of a Spoke-type permanent magnet synchronous motor in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of a winding method of an additional coil of a Spoke-type permanent magnet synchronous motor in an embodiment of the present application;

[0020] Figure 3 This is a relationship diagram between the magnetic energy product and magnetic field strength at different temperatures of the permanent magnet in the Spoke type permanent magnet synchronous motor in an embodiment of the present application;

[0021] Figure 4 This is a schematic structural diagram of the additional winding of the Spoke-type permanent magnet synchronous motor in an embodiment of the present application;

[0022] Figure 5 This is a magnetization flow chart of a Spoke-type permanent magnet synchronous motor in an embodiment of the present application;

[0023] Figure 6 This is a schematic diagram of a magnetizing device in an embodiment of the present application;

[0024] Figure 7 This is a circuit diagram of a magnetizing device in an embodiment of the present application;

[0025] Figure 8 This is a waveform diagram of the current and voltage of the additional winding during heating in an embodiment of the present application;

[0026] Figure 9 This is a waveform diagram of the additional winding current and the voltage of the second energy storage capacitor during magnetization in an embodiment of the present application;

[0027] Figure 10 This is a flowchart of the working process of the magnetizing device when magnetizing a Spoke type permanent magnet synchronous motor in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation of the present application will be clearly and completely described below in conjunction with the drawings in the implementation of the present application.

[0029] It should be noted that the words “first”, “second” and similar terms used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as “one” or “a” do not indicate a quantity limitation, but rather indicate the existence of at least one. “Multiple” or “several” means at least two. Words such as “include” or “comprise” mean that the elements or objects appearing before “include” or “comprises” cover the elements or objects listed after “include” or “comprises” and their equivalents, and do not exclude other elements or objects. Words such as “connected” or “connected” and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0030] like Figure 1 As shown, the present application provides a Spoke-type permanent magnet synchronous motor 100, hereinafter referred to as motor 100, which includes a housing 11, a stator 12, and a rotor 13. The housing 11 forms the main frame of the motor 100 and is capable of supporting the stator 12 and the rotor 13. The stator 12 is fixed in the housing 11 and is distributed in an annular or fan-shaped manner. A first installation space 101 is formed around the stator 12. The rotor 13 is disposed in the first installation space 101 and is connected to the housing 11. The rotor 13 can rotate relative to the stator 12 around its rotation axis.

[0031] Specifically, the stator 12 includes a stator core 121 and a plurality of armature windings 122. The stator core 121 is fixed to the housing 11. A plurality of mounting grooves 123 are evenly opened on the inner circumference of the stator core 121. The plurality of armature windings 122 are embedded in the plurality of mounting grooves 123 and are fixedly connected to the stator core 121. When the armature windings 122 are energized, a rotating magnetic field can be generated. The rotating magnetic field interacts with the rotor 13 to form a driving torque, thereby driving the rotor to rotate.

[0032] The rotor 13 includes permanent magnets 131, a rotor core 132, a support structure 133, a spacer 134, and an additional coil 135. The rotor core 132 comprises a plurality of core units 1321, which are spaced apart around the rotation axis, with gaps formed between adjacent core units 1321. The permanent magnets 131 are positioned in the gaps between any two adjacent core units 1321. The core units 1321 on either side of the permanent magnets 131 limit the position of the permanent magnets 131 in the tangential direction of the rotor 13.

[0033] The rotor core 132 defines a second installation space 102, within which the support structure 133 and the spacer 134 are disposed. A rotating shaft (not shown) extends through the support structure 133. The axis of the rotating shaft serves as the rotational axis of the rotor 13 and serves as the power output shaft for the motor 100. The rotating shaft is fixedly connected to the support structure 133, and the rotor core 132 is fixed to the outer wall of the support structure 133. When power is supplied to the armature winding 122, the permanent magnets 131, under the action of the rotating magnetic field, drive the rotating shaft to rotate along its circumferential direction.

[0034] The spacers 134 are connected between the support structure 133 and the core units 1321, with each spacer 134 corresponding to one core unit 1321. As will be appreciated, each spacer 134 corresponds to one permanent magnet 131. The spacers 134 serve as mounting supports for the additional coils 135, which are wound around the spacers 134. The spacers 134 are made of insulating, non-magnetic material, providing magnetic isolation during motor operation to prevent degradation of motor performance.

[0035] The additional coil 135 has a multiplexing end 1351 , a magnetizing end 1352 and a heating end 1353 . The multiplexing end 1351 and the magnetizing end 1352 are the head end and the tail end of the additional coil 135 respectively. The heating end 1353 is located between the multiplexing end 1351 and the magnetizing end 1352 .

[0036] The additional coil 135 can be connected to the magnetizing device. When the multiplexing end 1351 and the heating end 1353 are connected to the magnetizing device, the additional coil 135 can heat the permanent magnet 131 under the action of the magnetizing device; when the multiplexing end 1351 and the magnetizing end 1352 are connected to the magnetizing device, the additional coil 135 can magnetize the permanent magnet 131 under the action of the magnetizing device.

[0037] Through the above arrangement, the non-magnetic permanent magnet 131 can be first combined with the rotor core 132, and then the rotor 13 can be assembled into the first installation space 101 formed by the stator, thereby preventing the electromagnetic force between the permanent magnet 131 and other motor components from affecting the assembly of the rotor 13. By winding the additional coil 135 around the spacer 134 and connecting it to an external magnetizing device, before magnetizing the permanent magnet 131, the current generated by the magnetizing device is received by the reuse end 1351 and the heating end 1353 of the additional coil 135 to heat the permanent magnet 131. The current generated by the magnetizing device is then received by the reuse end 1351 and the magnetizing end 1352 of the additional coil 135 to magnetize the heated permanent magnet 131. On the one hand, this reduces the difficulty of combining the rotor 13 and the stator 12, and on the other hand, it improves the magnetization efficiency of the permanent magnet 131.

[0038] like Figure 2As shown, in some possible implementations, the spacer 134 includes a first portion 1341 and a second portion 1342. The first portion 1341 is tightly against the core unit 1321, and the second portion 1342 is tightly against the support structure 133. The additional coil 135 includes a first partial coil 1354 and a second partial coil 1355 connected to each other. The first partial coil 1354 is wound on the surface of the first portion 1341, and the second partial coil 1355 is wound on the surface of the second portion 1342. The reuse end 1351 is connected to the first partial coil 1354 and is connected to the head end of the first partial coil 1354. The heating end 1353 is connected to the first partial coil 1354 and is connected to the tail end of the first partial coil 1354. The magnetizing end 1352 is connected to the second partial coil 1355.

[0039] In some embodiments, the first partial coil 1354 is configured as a single-layer coil structure. The second partial coil 1355 has the same number of layers as the first partial coil 1354 and is wound in the same manner. The multiplexing end 1351 is connected to the head end of the first partial coil 1354, the heating end 1353 is connected to the tail end of the first partial coil 1354, and the magnetizing end 1352 is connected to the tail end of the second partial coil 1355.

[0040] In some embodiments, at least two layers of coil structures are stacked in the first coil section 1354, with the head ends of each layer of coil structures overlapping, and the tail end of the coil structure of the previous layer closer to the first portion 1341 is connected to the head end of the coil structure of the next layer farther from the first portion 1341. The number of coil layers in the second coil section 1355 is the same as that in the first coil section 1354, and the coil structures are wound in the same manner.

[0041] Optionally, the number of layers of the coil structures in the first partial coil 1354 and the second partial coil 1355 may be different.

[0042] like Figure 2 As shown, for example, the additional coil 135 uses 4mm*1.7mm flat copper wire, and the first part coil 1354 and the second part coil 1355 are arranged in a two-layer coil structure in a stacked form. The additional coil 135 has 28 turns of copper wire. Figure 2The number 1 in the figure represents the first turn of copper wire wound on pad 134, the number 2 represents the second turn of copper wire wound on pad 134, and the number 8 represents the eighth turn of copper wire wound on pad 134. The eighth turn of copper wire is wound outside the first turn of copper wire and connected to the first turn of copper wire. It can be understood that the number 28 represents the 28th turn of copper wire wound on pad 134. The 28th turn of copper wire is wound around the 21st turn of copper wire and connected to the 21st turn of copper wire. The reuse end 1351 is connected to the first turn of copper wire, the magnetization end 1352 is connected to the 28th turn of copper wire, and the heating end 1353 is connected to the 14th turn of copper wire.

[0043] It should be noted that when eddy current heating is performed on the permanent magnet 131, since the support structure 133 is usually a conductive steel plate, when eddy current heating is performed on the permanent magnet 131, the current of the additional coil 135 only flows through the portion away from the support structure 133, such as Figure 2 The 1st to 8th turns of copper wire shown in the figure make the energy consumed during eddy current heating be concentrated on the permanent magnet 131 .

[0044] In some possible implementations, the additional coils 135 wound on two adjacent pads 134 are connected in parallel, that is, the multiplexing ends 1351 of the additional coils 135 on two adjacent pads 134 are connected, the heating ends 1353 of the additional coils 135 on two adjacent pads 134 are connected, and the magnetizing ends 1352 of the additional coils 135 on two adjacent pads 134 are connected.

[0045] It should be noted that the additional coil 135 has two winding methods. When observed radially inward along the rotor 13, the clockwise winding method is defined as right-hand winding, and the counterclockwise winding method is called left-hand winding. The two additional coils 135 wound on adjacent pads 134 adopt different winding methods, so that the magnetic fields generated by the two adjacent additional coils 135 with the same voltage are opposite.

[0046] In some possible implementations, N consecutive additional coils 135 are connected to each other in parallel to form an additional winding, and the additional winding leads to a multiplexing end, a magnetizing end and a heating end, where N is a natural number greater than or equal to 2; when the multiplexing end and the heating end of the additional winding are connected to the magnetizing device, the additional winding is used to receive the alternating current generated by the magnetizing device, or the additional winding generates an alternating current under the alternating voltage provided by the magnetizing device, and the permanent magnet 131 generates an alternating magnetic field under the action of the alternating current flowing through the additional winding, and the permanent magnet 131 is eddy current heated under the alternating magnetic field.

[0047] For example, when multiple additional coils 135 are connected to form an additional winding, the multiplexing ends 1351 of the multiple additional coils 135 can be connected and led out to form the multiplexing end of the additional winding; the magnetizing ends 1352 of the multiple additional coils 135 can be connected and led out to form the magnetizing end of the additional winding; and the heating ends 1353 of the multiple additional coils 135 can be connected and led out to form the heating end of the additional winding.

[0048] In the specific magnetization process, the reuse end and the heating end of the additional winding are first connected to the magnetization device, so that the additional winding generates an alternating current under the alternating voltage provided by the magnetization device. The permanent magnet 131 generates an alternating magnetic field under the action of the alternating current flowing through the additional winding. The permanent magnet 131 will produce hysteresis loss and eddy current loss. The eddy current loss is mainly dissipated in the form of heat energy, thereby realizing eddy current heating of the permanent magnet 131.

[0049] After heating the permanent magnet 131, the additional winding's reuse and magnetization terminals are connected to a magnetizing device, causing the additional winding to generate a pulsed current under the high voltage provided by the magnetizing device, thereby magnetizing the permanent magnet 131. After heating, the magnetic domains of the permanent magnet 131 become less able to resist magnetization or re-magnetization. At high temperatures, the anisotropy constant of the magnetic domains decreases, making it easier for the permanent magnet 131 to overcome the internal anisotropy field and magnetize. Consequently, the external magnetizing field intensity required for the magnetic energy product of the permanent magnet 131 to reach saturation is lower.

[0050] The above arrangement, on the one hand, improves the connection efficiency between the additional winding's reused end, heating end, and magnetizing end and the external magnetizing device by changing the connection state between the additional winding's reused end, heating end, and magnetizing end to heat or magnetize the permanent magnet 131. Furthermore, by interconnecting multiple additional coils 135 to form an additional winding, multiple permanent magnets 131 can be heated or magnetized simultaneously, thereby improving the magnetization efficiency of the permanent magnets 131. Furthermore, the permanent magnets 131 exhibit higher magnetic properties when magnetized after the motor 100 is assembled.

[0051] like Figure 3 As shown, in the embodiment of the present application, at a temperature of 293K, the external magnetizing magnetic field strength required for the magnetization saturation of the permanent magnet 131 reaches 1200kA / m. As the temperature increases, the external magnetizing magnetic field strength required for the magnetization saturation of the permanent magnet 131 decreases. At a temperature of 353K, the external magnetizing magnetic field strength required for the magnetization saturation of the permanent magnet 131 only reaches 800kA / m. It can be seen that eddy current heating can significantly reduce the requirements for the magnetization pulse current, thereby improving the magnetization efficiency of the permanent magnet 131.

[0052] In some possible implementations, M consecutive permanent magnets 131 can be divided into a magnetizing group. When the magnetizing group is magnetized, the number of permanent magnets 131 in the magnetizing group and the number of additional coils 135 constituting the additional winding satisfy the following relationship: NM=1; where N represents the number of additional coils 135 constituting the additional winding, and M represents the number of permanent magnets.

[0053] Furthermore, at least two permanent magnets 131 are spaced between two adjacent magnetizing groups. The permanent magnets 131 between the two adjacent magnetizing groups are defined as spaced permanent magnets. After magnetizing each magnetizing group, the spaced permanent magnets are magnetized respectively.

[0054] Since the permanent magnets 131 are demagnetized by the external magnetic field after being heated, it is necessary to analyze the possible demagnetization effect of the magnetic field of the additional coil 135 corresponding to the unmagnetized permanent magnet 131 on the magnetized permanent magnet 131. It has been verified that when there are at least two permanent magnets between two adjacent magnetization groups, there is almost no mutual demagnetization effect between the magnetization of the two magnetization groups.

[0055] Exemplarily, three consecutive permanent magnets 131 are divided into a magnetization group, and the magnetization direction required for magnetization of any permanent magnet 131 in the magnetization group is consistent with the direction of the magnetic field generated by the additional winding corresponding to the magnetization group in the permanent magnet 131. Taking into account the mutual influence of the permanent magnets 131 in multiple magnetization groups during magnetization, there should be at least two permanent magnets 131 between two consecutive magnetization groups. Since the magnetization of multiple magnetization groups is completed circumferentially and then the magnetization of the spaced permanent magnets 131 is supplemented, the number of spaced permanent magnets 131 is consistent with the number of permanent magnets 131 in the magnetization group, which can achieve the purpose of reducing the number of magnetization times. Among them, the spaced permanent magnets 131 between two consecutive magnetization groups can be magnetized as a magnetization group during the supplementary magnetization process.

[0056] like Figure 4 As shown, when observed along the axial direction of the rotor 13, taking three continuous permanent magnets 131 as an example, the three permanent magnets 131 continuously distributed along the circumference of the rotor 13 are respectively defined as a first permanent magnet 1311, a second permanent magnet 1312 and a third permanent magnet 1313; when observed along the axial direction of the rotor 13, the four additional coils 135 continuously distributed along the circumference of the rotor 13 are respectively defined as a first additional coil 135a, a second additional coil 135b, a third additional coil 135c and a fourth additional coil 135d.

[0057] If the second permanent magnet 1312 is eddy-current heated, the first permanent magnet 1311 and the third permanent magnet 1313 can also generate an alternating magnetic field, so that the first permanent magnet 1311 and the third permanent magnet 1313 are heated, thereby reducing the external magnetizing magnetic field intensity required for magnetizing the first permanent magnet 1311 and the third permanent magnet 1313.

[0058] If the second permanent magnet 1312 is magnetized, the first permanent magnet 1311 and the third permanent magnet 1313 can be magnetized because the direction of the magnetic field generated by the second additional coil 135b and the third additional coil 135c corresponding to the second permanent magnet 1312 is consistent with the required magnetization direction of the first permanent magnet 1311 and the third permanent magnet 1313.

[0059] In some possible implementations, an eddy current shield (not shown) can be installed in the air gap between the rotor 13 and the stator 12. The shield is a non-magnetic aluminum plate with a sector-shaped cross-section. Eddy currents generated by the shield during magnetization can be used to enhance or adjust the external magnetic field through the magnetic effect of the eddy currents, thereby magnetizing the permanent magnets 131 and improving the magnetic saturation rate and heating efficiency of the permanent magnets 131.

[0060] In some possible implementations, when viewed along the axial direction of the rotor 13, the spacer 134 is T-shaped, and is at least partially located between the additional coil 135 and the permanent magnet 131. The spacer 134 and the permanent magnet 131 are arranged correspondingly, that is, the permanent magnet 131 is located at a symmetrical position between the two spacers 134.

[0061] For example, to ensure that the pad 134 can still play a magnetic isolation role under normal operation of the motor 100 and ensure the strength of the magnetizing magnetic field during magnetization, the pad 134 is made of Teflon material that is non-magnetic, has low electrical conductivity and high strength.

[0062] During assembly of motor 100, additional coil 135 is first secured to spacer 134 and cured with epoxy resin to enhance the strength of additional coil 135 and spacer 134. Rotor core 132 is then assembled with permanent magnet 131. Alternatively, additional coil 135 can be secured to spacer 134 by dipping or dripping paint, thereby enhancing the mechanical strength of additional coil 135.

[0063] In some possible implementations, when viewed along the radial direction of the rotor 13 , the additional coil 135 between two adjacent spacers 134 overlaps with the permanent magnet 131 .

[0064] It should be noted that any permanent magnet 131 corresponds to two adjacent additional coils 135, and when viewed radially along the rotor 13, any permanent magnet 131 is located symmetrically with respect to the corresponding two additional coils 135. Furthermore, because adjacent additional coils 135 utilize different winding methods, the currents flowing through these two additional coils 135 in opposite directions when viewed axially along the rotor 13.

[0065] That is, when any permanent magnet 131 is heated, the two permanent magnets 131 adjacent to it can also be heated; when any permanent magnet 131 is magnetized, the magnetization effects of the two permanent magnets 131 adjacent to it can be positively affected.

[0066] like Figure 5 As shown, the present application also provides a magnetizing method for the motor 100, which specifically includes the following steps:

[0067] Step S101: connecting the reuse end and the heating end of the additional winding corresponding to the magnetizing group to the magnetizing device respectively, so as to perform eddy current heating on the permanent magnets in the magnetizing group.

[0068] Step S102: connecting the reuse end and the magnetization end of the additional winding corresponding to the magnetization group to the magnetization device respectively, and magnetizing the permanent magnets in the magnetization group.

[0069] Step S103: heating and magnetizing the next magnetization group with at least two permanent magnets between them.

[0070] Step S104: eddy current heating and magnetization of the spaced permanent magnets.

[0071] like Figure 6 As shown, as an implementation, the present application further provides a magnetizing device 200 for use with the motor 100. The magnetizing device 200 includes a charging circuit 21, a heating energy storage circuit 22, a magnetizing energy storage circuit 23, and a discharge circuit 24. The charging circuit 21 is configured to generate current. The heating energy storage circuit 22 is connected to the charging circuit 21 and configured to receive the current generated by the charging circuit 21. The magnetizing energy storage circuit 23 is connected to the charging circuit 21 and is connected in parallel with the heating energy storage circuit 22. The magnetizing energy storage circuit 23 is configured to receive the current generated by the charging circuit 21. The discharge circuit 24 is connected to the heating energy storage circuit 22 and the magnetizing energy storage circuit 23 respectively. The discharge circuit 24 can be connected to the additional winding. The discharge circuit 24 is used to control the conduction between the heating energy storage circuit 22 and the additional winding, and to form an alternating current in the additional winding to heat the permanent magnet 131 corresponding to the additional winding 135; the discharge circuit 24 is also used to control the conduction between the magnetizing energy storage circuit 23 and the additional winding 135 to magnetize the permanent magnet 131.

[0072] Through the above arrangement, the magnetizing device 200 integrates the heating function and the magnetizing function, thereby avoiding the need to replace the magnetizing device 200 after heating the permanent magnet 131 , thereby reducing the time required for magnetizing the permanent magnet 131 .

[0073] like Figure 7As shown, in some possible implementations, the heating energy storage circuit 22 includes a first energy storage capacitor C1. When eddy current heating is performed on the permanent magnet 131, the first energy storage capacitor C1 provides a current flowing through the additional coil 135. The magnetization energy storage circuit 23 includes a second energy storage capacitor C2. When magnetizing the permanent magnet 131, the second energy storage capacitor C2 provides a current flowing through the additional coil 135. The capacity of the first energy storage capacitor C1 is greater than that of the second energy storage capacitor C2, and the charging voltage amplitude of the first energy storage capacitor C1 is lower than the charging voltage amplitude of the second energy storage capacitor C2.

[0074] In an embodiment of the present application, the charging circuit 21 includes a charging switch S1 , a first end of the charging switch S1 is coupled to an external power supply, and a second end of the charging switch S1 is coupled to a connection node between the heating energy storage circuit 22 and the magnetizing energy storage circuit 23 .

[0075] The heating energy storage circuit 22 includes a first energy storage switch S2. The second end of the first energy storage switch S2 is coupled to the second end of the charging switch S1. The second end of the first energy storage switch S2 is also coupled to the connection node between the heating energy storage circuit 22 and the magnetizing energy storage circuit 23. The first end of the first energy storage switch S2 is coupled to the first energy storage capacitor C1. If both the charging switch S1 and the first energy storage switch S2 are closed, the first energy storage capacitor C1 can be charged from an external power source. If the charging switch S1 is open and the first energy storage switch S2 is closed, the first energy storage capacitor C1 can provide additional winding energy for eddy current heating.

[0076] The magnetizing energy storage circuit 23 includes a second energy storage switch S3. The second end of the second energy storage switch S3 is coupled to the second end of the charging switch S1. The second end of the second energy storage switch S3 is also coupled to the connection node between the heating energy storage circuit 22 and the magnetizing energy storage circuit 23. The first end of the second energy storage switch S3 is coupled to the second energy storage capacitor C2. If both the charging switch S1 and the second energy storage switch S3 are closed, the second energy storage capacitor C2 can be charged by an external power source. If the charging switch S1 is open and the second energy storage switch S3 is closed, the second energy storage capacitor C2 can provide additional winding energy for magnetization.

[0077] In some possible implementations, the first energy storage capacitor C1 and the second energy storage capacitor C2 are both unipolar capacitors. Unipolar capacitors have a large capacity, which can reduce the charging frequency of the magnetizing device 200 and improve the magnetizing efficiency.

[0078] In some possible implementations, the discharge circuit 24 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, and a fourth switch tube Q4. The first end of the first switch tube Q1 is coupled to the first end of the third switch tube Q3, and the first end of the first switch tube Q1 is also coupled to the connection node of the heating energy storage circuit 22 and the magnetizing energy storage circuit 23; the second end of the second switch tube Q2 is coupled to the second end of the fourth switch tube Q4, and the second end of the second switch tube Q2 is also coupled to the connection node of the heating energy storage circuit 22 and the magnetizing energy storage circuit 23; the second end of the first switch tube Q1 is coupled to the first end of the second switch tube Q2, and the second end of the third switch tube Q3 is coupled to the first end of the fourth switch tube Q4; wherein the second end of the first switch tube Q1 and the second end of the third switch tube Q3 are used to connect to the additional winding.

[0079] In an embodiment of the present application, one end of the additional winding is coupled to the second end of the first switch tube Q1 and the first end of the second switch tube Q2, and the other end of the additional winding is coupled to the second end of the third switch tube Q3 and the first end of the fourth switch tube Q4.

[0080] If the magnetizing device 200 is used to heat the permanent magnet 131, the first switch tube Q1 and the fourth switch tube Q4 are first controlled to be turned on, and the current has the following first flow process: the current flows out from the positive electrode of the first energy storage capacitor C1, flows through the first end of the first switch tube Q1, the second end of the first switch tube Q1, the additional winding, the first end of the fourth switch tube Q4, and the second end of the fourth switch tube Q4, and flows out from the second end of the fourth switch tube Q4 to the negative electrode of the first energy storage capacitor C1.

[0081] The first and fourth switches Q1 and Q4 are then turned off, while the third and second switches Q3 and Q2 are turned on. Due to the current-maintaining effect of the additional winding's inductance, current does not actually flow immediately through the second and third switches Q2 and Q3. Instead, the current undergoes the following brief second flow process: the current flows from the negative electrode of the first energy storage capacitor C1, passes through the freewheeling diode D2, the additional winding, and the freewheeling diode D3, and finally flows out through the freewheeling diode D3 to the positive electrode of the first energy storage capacitor C1, charging the first energy storage capacitor C1 and completing energy recovery from the additional winding. The first and second flow processes together constitute the first heating process.

[0082] Due to the voltage of the first energy storage capacitor C1, the current in the additional winding quickly decays. At this time, the second switch tube Q2 and the third switch tube Q3 are still on. The current has the following third flow process: it flows out from the positive electrode of the first energy storage capacitor C1, flows through the first end of the third switch tube Q3, the second end of the third switch tube Q3, the additional winding, the first end of the second switch tube Q2, and the second end of the second switch tube Q2, and flows out from the second end of the second switch tube Q2 to the negative electrode of the first energy storage capacitor C1.

[0083] The second and third switches Q2 and Q3 are then turned off, while the first and fourth switches Q1 and Q4 are turned on. Due to the current-maintaining effect of the additional winding's inductance, current does not actually flow immediately through the first and fourth switches Q1 and Q4. Instead, the current undergoes the following brief fourth flow process: Current flows from the negative electrode of the first energy storage capacitor C1, passes through the freewheeling diode D4, the additional winding, and the freewheeling diode D1, and finally flows out through the freewheeling diode D1 to the positive electrode of the first energy storage capacitor C1, charging the first energy storage capacitor C1 and completing energy recovery from the additional winding. The third and fourth flow processes constitute the second heating process.

[0084] It should be noted that the direction of current flow formed by the additional winding during the first heating process is opposite to the direction of current flow during the second heating process. Therefore, the direction of the magnetic field generated during the first heating process is opposite to the direction of the magnetic field generated during the second heating process. Alternating the first heating process and the second heating process can enable the additional winding to generate an alternating current, thereby applying an alternating magnetic field to the permanent magnet 131, thereby realizing eddy current heating of the permanent magnet 131.

[0085] like Figure 8 The following are waveform diagrams of the current and voltage on the additional winding during the first and second heating processes in the embodiment of the present application, where T1 is the time stage of the first flow process, T2 is the time stage of the second flow process, T3 is the time stage of the third flow process, and T4 is the time stage of the fourth flow process. Since the first energy storage capacitor C1 in the embodiment of the present application adopts a unipolar capacitor and has a large capacity, the voltage of the first energy storage capacitor C1 does not drop substantially during multiple cycles consisting of a first heating process and a second heating process.

[0086] like Figure 7 As shown, in some possible implementations, if the magnetizing device 200 is used to magnetize the permanent magnet 131, the first switch Q1 and the fourth switch Q4 are controlled to be conductive, and the current has the following fifth flow process: the current flows out from the positive electrode of the second energy storage capacitor C2, flows sequentially through the first end of the first switch Q1, the second end of the first switch Q1, the additional winding, the first end of the fourth switch Q4, and the second end of the fourth switch Q4, and then flows out of the fourth switch Q4 from the second end of the fourth switch Q4 to the negative electrode of the second energy storage capacitor C2. This current is a unidirectional pulse current, so the additional winding applies a unidirectional pulse magnetic field to the permanent magnet 131 to magnetize the permanent magnet 131.

[0087] In the fifth flow process, the current decays when it reaches its peak value. When the current decays, it has little effect on the magnetization of the permanent magnet. However, some energy still remains in the additional winding, and it is considered to recover this energy.

[0088] The first switching tube Q1 and the fourth switching tube Q4 are controlled to be turned off. Due to the inductance effect of the additional winding maintaining the current, the current has the following sixth flow process: the current flows out from the negative electrode of the second energy storage capacitor C2, passes through the freewheeling diode D2, the additional winding, and the freewheeling diode D3 in sequence, and flows out from the freewheeling diode D3 to the positive electrode of the second energy storage capacitor C2, thereby charging the second energy storage capacitor C2 and completing energy recovery from the additional winding.

[0089] It should be noted that, in the fifth and sixth current flow processes, the current of the additional winding always flows in one direction, and the magnetic field applied by the additional winding to the permanent magnet 131 never alternates.

[0090] like Figure 9 As shown, it is a waveform diagram of the current of the additional winding and the voltage of the second energy storage capacitor C2 during the magnetization process in an embodiment of the present application, wherein T5 is the time stage of the current flowing through the additional winding in the fifth flow process, and T6 is the time stage of the current flowing through the additional winding in the sixth flow process.

[0091] Through the above arrangement, the energy of the first energy storage capacitor C1 and the second energy storage capacitor C2 is recovered, the charging time of the magnetizing device 200 is reduced, and the magnetizing efficiency of the motor 100 is improved.

[0092] In some possible implementations, the magnetizing device 200 includes a connection structure (not shown) composed of three metal plates that are not electrically connected to each other. One of the metal plates is connected to the reuse ends 1351 of the additional coils 135 , one is connected to the heating ends 1353 of the additional coils 135 , and one is connected to the magnetizing ends 1352 of the additional coils 135 .

[0093] Exemplarily, the metal plates are annular metal plates, with the outer diameter of the first annular metal plate being larger than that of the second annular metal plate, and the outer diameter of the second annular metal plate being larger than that of the third annular metal plate, such that the second annular metal plate is positioned within the first annular metal plate, and the third annular metal plate is positioned within the second annular metal plate. The first annular metal plate is connected to the multiplexing ends 1351 of the plurality of additional coils 135, the second annular metal plate is connected to the heating ends 1353 of the plurality of additional coils 135, and the third annular metal plate is connected to the magnetizing ends 1352 of the plurality of additional coils 135.

[0094] Through the above-mentioned arrangement, the connection structure can be connected to the multiplexing end 1351, heating end 1353 and magnetizing end 1352 of multiple additional coils 135. By means of metal bolt conduction, metal contact conduction, etc., the multiplexing end 1351, heating end 1353 and magnetizing end 1352 of these additional coils 135 can be respectively connected to the three annular metal plates. These additional coils 135 are connected in parallel to form the additional winding, and the external ports of the three metal plates are the multiplexing end, heating end and magnetizing end of the additional winding.

[0095] like Figure 10 As shown, in the embodiment of the present application, the magnetizing device is used to magnetize the motor 100, and the following steps are included:

[0096] Step S201 : charging the first energy storage capacitor C1 and the second energy storage capacitor C2 of the magnetizing device 200 .

[0097] Step S202: connecting the additional coils 135 corresponding to the set of permanent magnets 131 to be magnetized, setting the eddy current heating frequency, and performing eddy current heating on the set of permanent magnets 131 to be magnetized.

[0098] Step S203 : After eddy current heating a group of permanent magnets 131 to a desired temperature, magnetizing the group of permanent magnets 131 is performed.

[0099] Step S204: After magnetizing one group of permanent magnets 131, the magnetizing device 200 is disassembled and the voltage of the first energy storage capacitor C1 or the second energy storage capacitor C2 is checked to see if it drops to a specified threshold. If it drops to the specified threshold, it means that the energy of the energy storage capacitor is insufficient to complete the next heating or magnetization, and the first energy storage capacitor C1 and the second energy storage capacitor C2 need to be charged. If the voltage of the first energy storage capacitor C1 and the second energy storage capacitor C2 does not drop to the specified threshold, the additional coil 135 corresponding to the next group of permanent magnets 131 is connected to prepare for magnetization of the next group of permanent magnets 131.

[0100] The above steps are performed until all permanent magnets 131 are magnetized.

[0101] Through the above arrangement, the magnetizing device 200 is used to complete the heating and magnetization of the permanent magnet 131 , without the need to frequently switch the equipment used for heating and magnetization, thereby improving the magnetization efficiency of the motor 100 .

[0102] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims appended to this application.

Claims

1. A Spoke-type permanent magnet synchronous motor, comprising: stator; a rotor disposed in a space surrounded by the stator and capable of rotating relative to the stator about its rotation axis; Characterized in that the rotor comprises: A rotor core, the rotor core comprising a plurality of core units, wherein the plurality of core units are arranged at intervals around the rotation axis; a permanent magnet, wherein the permanent magnet is arranged in a gap between two adjacent core units; a support structure, the support structure being arranged in a space surrounded by the rotor core; Spacers, the spacers being connected between the support structure and the core units, each of the spacers being connected to one core unit; an additional coil, the additional coil being wound around the pad, the additional coil having a reuse end, a magnetizing end, and a heating end, the reuse end and the magnetizing end being the head end and the tail end of the additional coil respectively, and the heating end being located between the reuse end and the magnetizing end; The additional coil can be connected to a magnetizing device. When the multiplexing end and the heating end are connected to the magnetizing device, the additional coil can heat the permanent magnet under the action of the magnetizing device; when the multiplexing end and the magnetizing end are connected to the magnetizing device, the additional coil can magnetize the permanent magnet under the action of the magnetizing device.

2. The Spoke type permanent magnet synchronous motor according to claim 1, characterized in that: N consecutive additional coils can be connected to each other to form an additional winding, and the additional winding leads to a multiplexing end, a magnetizing end, and a heating end, wherein N is a natural number greater than or equal to 2; When the multiplexing end and the heating end of the additional winding are connected to the magnetizing device, the additional winding is used to receive the alternating current generated by the magnetizing device. The permanent magnet generates an alternating magnetic field under the action of the alternating current flowing through the additional winding, and the permanent magnet performs eddy current heating under the alternating magnetic field.

3. The Spoke type permanent magnet synchronous motor according to claim 2, characterized in that: The continuous M permanent magnets can be divided into a magnetization group. When the magnetization group is magnetized, the number of the permanent magnets in the magnetization group and the number of the additional coils constituting the additional winding satisfy the following relationship: NM=1; Wherein, N represents the number of the additional coils constituting the additional winding, and M represents the number of the permanent magnets.

4. The Spoke type permanent magnet synchronous motor according to claim 3, characterized in that: There are at least two permanent magnets between two adjacent magnetization groups. The permanent magnets between two adjacent magnetization groups are defined as interval permanent magnets. After magnetizing each magnetization group, the interval permanent magnets are magnetized respectively.

5. The Spoke type permanent magnet synchronous motor according to claim 1, characterized in that: The spacer includes a first portion and a second portion, the first portion is tightly against the core unit, and the second portion is tightly against the support structure; the additional coil includes a first portion of coil and a second portion of coil connected to each other, the first portion of coil is wound on the surface of the first portion, and the second portion of coil is wound on the surface of the second portion; The multiplexing end is connected to the first portion of the coil and is connected to the head end of the first portion of the coil; the heating end is connected to the first portion of the coil and is connected to the tail end of the first portion of the coil; The magnetizing end is connected to the second portion of the coil.

6. The Spoke type permanent magnet synchronous motor according to claim 1, characterized in that: When viewed along the extension direction of the rotation axis, the spacer is T-shaped, and at least part of the spacer is located between the additional coil and the permanent magnet.

7. The Spoke type permanent magnet synchronous motor according to claim 1, characterized in that: When viewed along the radial direction of the rotor, the additional coil between two adjacent spacers overlaps with the permanent magnet.

8. A magnetizing device, applied to the Spoke type permanent magnet synchronous motor according to any one of claims 1 to 7, characterized in that: The magnetizing device comprises: a charging circuit, the charging circuit being configured to generate an electric current; a heating energy storage circuit, the heating energy storage circuit being connected to the charging circuit and configured to receive current generated by the charging circuit; a magnetizing energy storage circuit, the magnetizing energy storage circuit being connected to the charging circuit and configured to receive current generated by the charging circuit, the magnetizing energy storage circuit being connected in parallel with the heating energy storage circuit; A discharge circuit is connected to the heating energy storage circuit and the magnetizing energy storage circuit. The discharge circuit can be connected to an additional coil. The discharge circuit is used to control the heating energy storage circuit to be conductive with the additional coil and to form an alternating current in the additional coil to perform eddy current heating on the permanent magnet corresponding to the additional coil, or to control the magnetizing energy storage circuit to be conductive with the additional coil to magnetize the permanent magnet.

9. The magnetizing device according to claim 8, characterized in that: The heating energy storage circuit includes a first energy storage capacitor. When the permanent magnet is eddy-current heated, the first energy storage capacitor provides a current flowing through the additional coil. The magnetizing energy storage circuit includes a second energy storage capacitor. When the permanent magnet is magnetized, the second energy storage capacitor provides a current flowing through the additional coil. The capacity of the first energy storage capacitor is greater than the capacity of the second energy storage capacitor, and the charging voltage amplitude of the first energy storage capacitor is lower than the charging voltage amplitude of the second energy storage capacitor.

10. The magnetizing device according to claim 8, characterized in that: The discharge circuit includes a first switching tube, a second switching tube, a third switching tube and a fourth switching tube. The first end of the first switching tube is coupled to the first end of the third switching tube, and the first end of the first switching tube is also coupled to the connection node of the heating energy storage circuit and the magnetizing energy storage circuit; the second end of the second switching tube is coupled to the second end of the fourth switching tube, and the second end of the second switching tube is also coupled to the connection node of the heating energy storage circuit and the magnetizing energy storage circuit; the second end of the first switching tube is coupled to the first end of the second switching tube, and the second end of the third switching tube is coupled to the first end of the fourth switching tube; wherein the second end of the first switching tube and the second end of the third switching tube are used to connect the additional coil.

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