Rotor, adjustable flux permanent magnet synchronous motor and working method thereof

Abstract

The application provides a rotor, an adjustable flux type permanent magnet synchronous motor and a working method thereof. The adjustable flux type permanent magnet synchronous motor comprises a stator and a rotor, the rotor is rotatably installed in a containing cavity of the stator, the stator comprises a stator core and a stator winding, the stator winding is wound on the stator core, the rotor comprises a rotor core and a rotating shaft, and the rotor core is installed on the rotating shaft; a plurality of tooth portions are arranged on the outer periphery of the rotor core, a magnet mounting groove is arranged on each tooth portion, a permanent magnet is installed in the magnet mounting groove, and the magnetic pole directions of two adjacent permanent magnets are oppositely arranged; a group of rotor windings are wound on the outer periphery of each tooth portion; the motor further comprises a rotor winding power supply assembly, and the rotor winding power supply assembly supplies power to the rotor winding. The method is applied to the motor. The adjustable flux type permanent magnet synchronous motor can adjust the magnetic flux.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of permanent magnet synchronous motor, in particular, it relates to a rotor of adjustable flux type permanent magnet synchronous motor, and further relates to an adjustable flux type permanent magnet synchronous motor, and further relates to a working method of the adjustable flux type permanent magnet synchronous motor. BACKGROUND

[0002] The permanent magnet synchronous motor has simple structure, low loss and high power factor, compared with the electrically excited motor, because there is no brush, commutator and other devices, no reactive excitation current is needed, so the stator current and resistance loss are small, the efficiency is higher, the excitation torque is larger, and the controllability is better.

[0003] The permanent magnet synchronous motor is excited by the permanent magnet of the rotor, with the increase of the rotating speed, the motor voltage gradually reaches the voltage limit that can be output by the inverter, at this time, in order to continue to increase the rotating speed, the size and phase of the stator current need to be adjusted to increase the direct-axis demagnetizing current to equivalent to the field weakening, so as to improve the rotating speed. The field weakening capacity of the motor is mainly related to the direct-axis reactance and back electromotive force, but the permanent magnet is connected in series in the direct-axis magnetic circuit, so the direct-axis magnetic circuit generally has large magnetic resistance and small field weakening capacity, and when the motor back electromotive force is large, the maximum rotating speed of the motor will also be reduced. Therefore, the method of adjusting the size and phase of the stator current to increase the direct-axis demagnetizing current to equivalent to the field weakening to improve the rotating speed often needs larger current and increases the energy consumption.

[0004] Therefore, it is necessary to consider a more optimal structure of the permanent magnet synchronous motor. SUMMARY

[0005] The first object of the present application is to provide an adjustable flux type permanent magnet synchronous motor with adjustable flux.

[0006] The second object of the present application is to provide a rotor of the adjustable flux type permanent magnet synchronous motor with adjustable flux.

[0007] The third object of the present application is to provide a working method of the adjustable flux type permanent magnet synchronous motor with adjustable flux, improved low-speed load capacity and improved high-speed rotating speed range.

[0008] In order to achieve the above-mentioned first object, the adjustable flux type permanent magnet synchronous motor provided by the application comprises a stator and a rotor, the rotor is rotatably installed in a containing cavity of the stator, the stator comprises a stator core and a stator winding, the stator winding is wound on the stator core, the rotor comprises a rotor core and a rotating shaft, and the rotor core is installed on the rotating shaft; a plurality of tooth portions are arranged on the outer periphery of the rotor core, a magnet installation slot is arranged on each tooth portion, a permanent magnet is installed in the magnet installation slot, and the magnetic pole directions of two adjacent permanent magnets are oppositely arranged; a group of rotor windings are wound on the outer periphery of each tooth portion; and the motor further comprises a rotor winding power supply assembly, which supplies power to the rotor windings.

[0009] As can be seen from the above scheme, the adjustable flux type permanent magnet synchronous motor of the application can adjust the magnetic flux by increasing the windings around the permanent magnets of the rotor, and can generate magnetic fields with the same or opposite magnetic pole directions of the permanent magnets through the windings, thereby playing a role in adjusting the magnetic flux, and both the low-speed load-carrying capacity and the operating speed range can be greatly expanded.

[0010] In a further scheme, the rotor winding power supply assembly comprises an induction coil assembly, a power supply coil assembly and a power supply control circuit, the rotor winding is electrically connected with the induction coil assembly, the power supply coil assembly is electrically connected with the power supply control circuit, and the power supply coil assembly supplies power to the induction coil assembly.

[0011] As can be seen from the above scheme, the rotor winding power supply assembly supplies power through the induction coil assembly and the power supply coil assembly, and does not need a brush, thereby improving the reliability of the motor and making the maintenance more convenient.

[0012] In a further scheme, the induction coil assembly comprises a first coil fixing plate and at least two induction coils, the first coil fixing plate is coaxially installed with the rotating shaft and rotates coaxially, and all the induction coils are arranged on the first coil fixing plate along the circumferential direction of the rotating shaft.

[0013] As can be seen from the above scheme, the induction coil assembly is provided with the first coil fixing plate and at least two induction coils, and the first coil fixing plate is coaxially installed with the rotating shaft and rotates coaxially, thereby ensuring the stability of the induction coils when the rotor rotates.

[0014] In a further scheme, the number of the induction coils is the same as the number of the rotor windings, and one induction coil corresponds to one rotor winding.

[0015] As can be seen from the above scheme, the number of the induction coils is the same as the number of the rotor windings, thereby facilitating one-to-one corresponding control of the current directions of the rotor windings.

[0016] In a further scheme, the number of the induction coils is half of the number of the rotor windings; two adjacent rotor windings are connected in series, and the magnetic pole directions of the two series-connected rotor windings are opposite.

[0017] Therefore, when the number of the induction coils is half of the number of the rotor windings, the adjacent two rotor windings can be connected in series, and the magnetic pole directions of the two series-connected rotor windings are opposite, so that the two windings can be controlled by one induction coil, thereby reducing the number of the induction coils and saving space.

[0018] In a further aspect, the power coil assembly includes a second coil fixing plate and at least two power coils, the second coil fixing plate is coaxially installed with the rotating shaft, and all the power coils are arranged on the second coil fixing plate along the circumferential direction of the rotating shaft.

[0019] Therefore, the power coil assembly is provided with the second coil fixing plate and the at least two power coils, the second coil fixing plate is coaxially installed with the rotating shaft, and all the power coils are arranged on the second coil fixing plate along the circumferential direction of the rotating shaft, so that the power coil assembly in rotation can be conveniently powered.

[0020] In a further aspect, the number of the power coils is equal to the number of the induction coils in the induction coil assembly.

[0021] Therefore, the number of the power coils is equal to the number of the induction coils in the induction coil assembly, so that the power coils can be conveniently powered at the same time.

[0022] In a further aspect, the power coil assembly is installed on the front end cover or the rear end cover of the motor.

[0023] Therefore, the power coil assembly is installed on the front end cover or the rear end cover of the motor, and can be installed as needed.

[0024] In a further aspect, the permanent magnets are installed on the rotor core in a radial or tangential manner.

[0025] Therefore, the permanent magnets can be installed on the rotor core in a radial or tangential manner, and can be set according to the application scenario.

[0026] In order to achieve the above-mentioned second purpose, the rotor of the adjustable flux type permanent magnet synchronous motor provided by the present application includes a rotor core and a rotating shaft, the rotor core is installed on the rotating shaft; the outer periphery of the rotor core is provided with a plurality of tooth portions, each tooth portion is provided with a magnet mounting groove, a permanent magnet is installed in the magnet mounting groove, and the magnetic pole directions of adjacent two permanent magnets are oppositely arranged; and a group of rotor windings is wound on the outer periphery of each tooth portion.

[0027] In order to achieve the above-mentioned third purpose, the working method of the adjustable flux type permanent magnet synchronous motor provided by the present application includes: obtaining the rotating speed of the rotor; when the rotating speed of the rotor is in a preset low speed range, controlling the rotor windings to generate a magnetic field with the same magnetic pole direction as that of the corresponding permanent magnet; and when the rotating speed of the rotor is in a preset high speed range, controlling the rotor windings to generate a magnetic field with the opposite magnetic pole direction to that of the corresponding permanent magnet.

[0028] From the above scheme, the adjustable flux permanent magnet synchronous motor of the present application can generate the same or opposite magnetic field of the magnetic pole direction of the permanent magnet through the winding by adding the winding around the permanent magnet of the rotor, so as to play the role of adjusting the magnetic flux. At low speed, the induced coil current generates the magnetic field in the same direction of the permanent magnet, increases the electromagnetic torque, at high speed, the induced coil current generates the magnetic field in the opposite direction of the permanent magnet, weakens the magnetic field generated by the permanent magnet, so as to reduce the back electromotive force, obtain higher speed range, so as to realize the effect of improving the low speed load carrying capacity and greatly expanding the running speed range. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the structure sectional view of the first embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0030] Figure 2 is the installation structure diagram of the rotor, rotor winding power supply assembly and rear end cover in the first embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0031] Figure 3 is the installation structure diagram of the rotor and the induction coil assembly in the first embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0032] Figure 4 is the structure diagram of the induction coil assembly in the first embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0033] Figure 5 is the structure diagram of the power supply coil assembly in the first embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0034] Figure 6 is the installation structure diagram of the rotor and the induction coil assembly in the second embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0035] Figure 7 is the structure sectional view of the third embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0036] Figure 8 is the installation structure diagram of the permanent magnet in the rotor core in the fourth embodiment of the adjustable flux permanent magnet synchronous motor of the present application.

[0037] The present application is further described below in combination with the drawings and embodiments. DETAILED DESCRIPTION

[0038] The first embodiment of the adjustable flux permanent magnet synchronous motor:

[0039] As Figure 1As shown, in the embodiment, the adjustable flux permanent magnet synchronous motor comprises a shell 1, a stator 2, a rotor 3 and a rotor winding power supply assembly 4, the stator 2 and the rotor 3 are installed in the shell 1. The rotor 3 is rotatably installed in the accommodating cavity of the stator 2.

[0040] The stator 2 comprises a stator core 21 and a stator winding 22, the stator winding 22 is wound on the stator core 21. The stator core 21 is made of silicon steel sheets, and the stator winding 22 is wound on the stator core 21 through a skeleton (not shown), and the winding of the stator winding 22 on the stator core 21 is a technology known to those skilled in the art, which will not be described here.

[0041] Referring to Figure 2 and Figure 3 , the rotor 3 comprises a rotor core 31 and a rotating shaft 32, the rotor core 31 is installed on the rotating shaft 32. The outer periphery of the rotor core 31 is provided with a plurality of tooth portions 311, and each tooth portion 311 is provided with a magnet mounting groove 312 on the side facing the rotating shaft 32, and a permanent magnet 33 is installed in the magnet mounting groove 312, and the magnetic pole directions of adjacent two permanent magnets 33 are oppositely arranged. The outer periphery of each tooth portion 311 is wound with a set of rotor windings 313, and the rotor winding power supply assembly 4 supplies power to the rotor windings 313. The number of tooth portions 311 is even, and the number of tooth portions 311 can be set as required, and in the embodiment, the number of tooth portions 311 is 10. The permanent magnets 33 are installed on the rotor core 31 in a radial manner.

[0042] The rotor winding power supply assembly 4 comprises an induction coil assembly 41, a power supply coil assembly 42 and a power supply control circuit (not shown), the rotor windings 313 are electrically connected with the induction coil assembly 41, the power supply coil assembly 42 and the power supply control circuit are electrically connected, and the power supply coil assembly 42 supplies power to the induction coil assembly 41. In the embodiment, the induction coil assembly 41 is installed on the rotating shaft 32, and the power supply coil assembly 42 is installed on the rear end cover 11 of the shell 1.

[0043] Referring to Figure 4 , in the embodiment, the induction coil assembly 41 comprises a first coil fixing plate 411 and at least two induction coils 412, the first coil fixing plate 411 is coaxially installed and coaxially rotated with the rotating shaft 32, all the induction coils 412 are arranged on the first coil fixing plate 411 along the circumference of the rotating shaft 32, and there is a gap between adjacent two induction coils 412. In the embodiment, a first rotating shaft hole 413 is arranged in the central region of the first coil fixing plate 411, and the rotating shaft 32 penetrates through the first rotating shaft hole 413, so that the first coil fixing plate 411 is installed on the rotating shaft 32.

[0044] The number of the induction coils 412 is half of the number of the rotor windings 313, two adjacent rotor windings 313 are connected in series, and the magnetic pole directions generated by the two rotor windings 313 connected in series are opposite. In the embodiment, the number of the induction coils 412 is 5, the number of the rotor windings 313 is 10, the positive poles of two adjacent rotor windings 313 are electrically connected to the first output end of the corresponding induction coil 412, and the negative poles of the two adjacent rotor windings 313 are electrically connected to the second output end of the corresponding induction coil 412.

[0045] Referring to Figure 5 In the embodiment, the power supply coil assembly 42 includes a second coil fixing plate 421 and at least two power supply coils 422. The second coil fixing plate 421 is coaxially installed with the rotating shaft 32, and all the power supply coils 422 are arranged on the second coil fixing plate 421 along the circumferential direction of the rotating shaft 32, and there is a gap between two adjacent power supply coils 422. The number of the power supply coils 422 is equal to the number of the induction coils 412 in the induction coil assembly 41. The area of the power supply coil 422 is greater than the area of the induction coil 412.

[0046] In order to better understand the present application, the working method of the adjustable flux permanent magnet synchronous motor is described below.

[0047] In the working process of the adjustable flux permanent magnet synchronous motor of the embodiment, first, the rotating speed of the rotor 3 is obtained. When the motor works, the motor control circuit (not shown) supplies power to the stator winding 22 to generate a magnetic field. Under the joint action of the stator winding 22 and the permanent magnet 33, the rotor 3 rotates at a set rotating speed. By reading the rotating speed parameter of the rotor 3, the current rotating speed of the rotor 3 can be determined.

[0048] After the rotating speed of the rotor 3 is obtained, when the rotating speed of the rotor 3 is in a preset low speed range, the rotor winding 313 generates a magnetic field with the same magnetic pole direction as the corresponding permanent magnet 33. The preset low speed range is set according to experimental data. When the rotor 3 rotates at a low speed, the magnetic energy generated by the stator winding 22 is weak, and thus the load carrying capacity is weak. At this time, the current direction of the power supply coil 422 in the power supply coil assembly 42 is controlled by the power supply control circuit, so as to control the current direction of the induction coil 412, so that the magnetic field generated by the induction coil 412 has the same magnetic pole direction as the magnetic pole direction of the permanent magnet 33 around which the rotor winding 313 is wound, thereby further increasing the magnetic energy, increasing the motor torque, and improving the load carrying capacity.

[0049] In addition, after the speed of the rotor 3 is obtained, when the speed of the rotor 3 is in a preset high speed range, the rotor winding 313 is controlled to generate a magnetic field opposite to the magnetic pole direction of the corresponding permanent magnet 33. The preset high speed range is set in advance according to experimental data. When the rotor 3 rotates at a high speed, due to the presence of the permanent magnet 33, the stator winding 22 moves in a cutting magnetic induction line, thereby causing a high counter electromotive force in the stator winding 22, which requires a high voltage to drive the stator winding 22 to reach a preset speed. At this time, the power supply control circuit controls the current direction of the power supply coil 422 in the power supply coil assembly 42, so that the magnetic field generated by the induction coil 412 is opposite to the magnetic pole direction of the permanent magnet 33 around which the rotor winding 313 is wound, thereby weakening the magnetic flux generated by the permanent magnet 33 and reducing the counter electromotive force, without affecting the current of the stator winding 22, and a higher speed range can be obtained.

[0050] It should be noted that the rotor winding power supply assembly 4 can also supply power to the rotor winding 313 in the form of a brush. The structure of the brush power supply is a known technology in the art, and will not be described here.

[0051] Second embodiment of the adjustable flux permanent magnet synchronous motor:

[0052] The adjustable flux permanent magnet synchronous motor of the present embodiment is different from the first embodiment only in the number of induction coils. Only the difference will be described below, and the reference numerals are used in the first embodiment.

[0053] Referring to Figure 6 , the number of induction coils 412 is the same as the number of rotor windings 313, and one induction coil 412 supplies power to one rotor winding 313. In the present embodiment, the number of induction coils 412 and the number of rotor windings 313 are both 10.

[0054] Third embodiment of the adjustable flux permanent magnet synchronous motor:

[0055] The adjustable flux permanent magnet synchronous motor of the present embodiment is different from the first embodiment only in the installation position of the power supply coil assembly. Only the difference will be described below, and the reference numerals are used in the first embodiment.

[0056] Referring to Figure 7 , in the present embodiment, the power supply coil assembly 42 is installed on the front end cover 12 of the housing 1.

[0057] Fourth embodiment of the adjustable flux permanent magnet synchronous motor:

[0058] The adjustable flux permanent magnet synchronous motor of the present embodiment is different from the first embodiment only in the installation position of the permanent magnet. Only the difference will be described below, and the reference numerals are used in the first embodiment.

[0059] Referring to Figure 8 The permanent magnet 33 is tangentially mounted on the rotor core 31.

[0060] From the above, the adjustable magnetic flux type permanent magnet synchronous motor can produce the same or opposite magnetic field with the magnetic pole direction of the permanent magnet 33 through the winding around the permanent magnet 33 of the rotor 3, so as to play the role of adjusting the magnetic flux, which can improve the low-speed load capacity and greatly expand the operating speed range.

[0061] It should be noted that the above is only the preferred embodiment of the present application, but the design concept of the application is not limited to this, and any non-essential modification of the application made by using this concept also falls within the protection scope of the application.

Claims

1. An adjustable flux permanent magnet synchronous motor, comprising a stator and a rotor, wherein the rotor is rotatably mounted within a cavity of the stator, the stator comprising a stator core and stator windings wound on the stator core, and the rotor comprising a rotor core and a shaft, the rotor core being mounted on the shaft; characterized in that: The outer periphery of the rotor core is provided with multiple teeth, each tooth is provided with a magnet mounting slot, a permanent magnet is installed in the magnet mounting slot, and the magnetic poles of two adjacent permanent magnets are arranged in opposite directions. Each of the teeth has a set of rotor windings wound around its outer periphery; The motor also includes a rotor winding power supply assembly, which supplies power to the rotor winding; When the rotor speed is within a preset low speed range, the rotor winding generates a magnetic field with the same magnetic pole direction as the corresponding permanent magnet. When the rotor speed is within a preset high-speed range, the rotor winding generates a magnetic field opposite to the direction of the magnetic pole of the corresponding permanent magnet.

2. The adjustable flux permanent magnet synchronous motor according to claim 1, characterized in that: The rotor winding power supply assembly includes an induction coil assembly, a power supply coil assembly, and a power supply control circuit. The rotor winding is electrically connected to the induction coil assembly, and the power supply coil assembly is electrically connected to the power supply control circuit. The power supply coil assembly supplies power to the induction coil assembly.

3. The adjustable flux permanent magnet synchronous motor according to claim 2, characterized in that: The induction coil assembly includes a first coil fixing plate and at least two induction coils. The first coil fixing plate is coaxially mounted and rotates with the rotating shaft. All the induction coils are arranged on the first coil fixing plate along the circumference of the rotating shaft.

4. The adjustable flux permanent magnet synchronous motor according to claim 3, characterized in that: The number of induction coils is the same as the number of rotor windings, and one induction coil supplies power to one rotor winding.

5. The adjustable flux permanent magnet synchronous motor according to claim 3, characterized in that: The number of induction coils is half the number of rotor windings; Two adjacent rotor windings are connected in series, and the magnetic poles generated by the two rotor windings connected in series are in opposite directions.

6. The adjustable flux permanent magnet synchronous motor according to any one of claims 2 to 5, characterized in that: The power supply coil assembly includes a second coil fixing plate and at least two power supply coils. The second coil fixing plate is coaxially mounted with the rotating shaft, and all the power supply coils are arranged on the second coil fixing plate along the circumference of the rotating shaft.

7. The adjustable flux permanent magnet synchronous motor according to claim 6, characterized in that: The number of power supply coils is equal to the number of induction coils in the induction coil assembly.

8. The adjustable flux permanent magnet synchronous motor according to claim 6, characterized in that: The power supply coil assembly is mounted on the front or rear cover of the motor.

9. The adjustable flux permanent magnet synchronous motor according to any one of claims 1 to 5, characterized in that: The permanent magnet is mounted radially or tangentially on the rotor core.

10. A rotor for an adjustable flux permanent magnet synchronous motor, comprising a rotor core and a shaft, wherein the rotor core is mounted on the shaft; characterized in that: The outer periphery of the rotor core is provided with multiple teeth, each tooth is provided with a magnet mounting slot, a permanent magnet is installed in the magnet mounting slot, and the magnetic poles of two adjacent permanent magnets are arranged in opposite directions. Each of the teeth has a set of rotor windings wound around its outer periphery; When the rotor speed is within a preset low speed range, the rotor winding generates a magnetic field with the same magnetic pole direction as the corresponding permanent magnet. When the rotor speed is within a preset high-speed range, the rotor winding generates a magnetic field opposite to the direction of the magnetic pole of the corresponding permanent magnet.

11. A method for operating an adjustable flux permanent magnet synchronous motor, the motor comprising a stator and a rotor, the rotor being rotatably mounted within a cavity of the stator, the stator comprising a stator core and stator windings wound on the stator core, the rotor comprising a rotor core and a shaft, the rotor core being mounted on the shaft; characterized in that: The outer periphery of the rotor core is provided with multiple teeth, each tooth is provided with a magnet mounting slot, and a permanent magnet is installed in the magnet mounting slot. The magnetic poles of two adjacent permanent magnets are arranged in opposite directions. A set of rotor windings is wound around the outer periphery of each tooth. The motor also includes a rotor winding power supply assembly, which supplies power to the rotor windings. The method includes: Obtain the rotational speed of the rotor; When the rotor speed is within a preset low speed range, the rotor winding is controlled to generate a magnetic field with the same magnetic pole direction as the corresponding permanent magnet. When the rotor speed is within a preset high-speed range, the rotor winding is controlled to generate a magnetic field opposite to the magnetic pole direction of the corresponding permanent magnet.

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