Stator composite type double-mechanical-port permanent magnet motor

Abstract

The invention belongs to the field of motors, and discloses a stator composite type double-mechanical-port permanent magnet motor. The double-mechanical-port permanent magnet motor comprises a first armature stator, a first rotor, a composite stator and a second rotor which are coaxially arranged in sequence, and an axial air gap is formed between every two adjacent components. The composite stator comprises an excitation stator and a second armature stator which are distributed in the extending direction from the first armature stator to the second rotor. The current of the armature windings in the first armature stator and the second armature stator is controlled, so that the double-mechanical-port permanent magnet motor operates in a first armature stator independent driving mode, a second armature stator independent driving mode and a first armature stator and second armature stator combined driving mode. The composite stator serves as an excitation unit and an armature unit, so that the utilization rate of the permanent magnets and the power density of the permanent magnet motor are effectively improved. The three motor driving modes can be matched with different speed and load operation conditions, and multi-mode operation of the motor is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of motors, and in particular relates to a stator composite dual-mechanical port permanent magnet motor and a torque distribution method thereof. Background Art

[0002] With the increasing severity of air pollution and the increasing scarcity of oil resources, zero-pollution electric vehicles are gradually entering the market. As a key component of electric vehicles, the selection of automotive drive motors has become the key to improving the performance of electric vehicles. Axial permanent magnet motors not only inherit many advantages of permanent magnet motors such as high power density and high torque density, but also have the advantages of compact structure and high utilization rate of silicon steel sheets of axial motors. They are particularly suitable for the field of new energy vehicles with large torque requirements.

[0003] However, most of the vehicle drive motors currently studied are single-motor systems. In order to consider extreme operating conditions such as climbing and high speed, the motor size is often chosen to be larger. In actual processes, the motors often operate at low speed and low load, which greatly reduces the efficiency of the motor and causes a lot of energy waste.

[0004] At present, a type of dual-rotor motor uses a two-layer rotor structure to achieve dual mechanical port output. It has a compact structure and high integration. Compared with traditional permanent magnet motors, the total torque value of the combined internal and external motors is greatly increased and the efficiency of the motor is also effectively improved. However, this type of motor shares the same stator, which inevitably leads to coupling of the magnetic circuit on the stator side, thereby affecting the independent operation ability of the internal and external motors. Summary of the invention

[0005] The purpose of the present invention is to at least partially solve the above-mentioned technical problems, and aims to provide a stator composite dual mechanical port permanent magnet motor and a torque distribution method thereof, which can not only improve the power density of the permanent magnet motor, but also realize the multi-mode operation of the permanent magnet motor and meet various operating conditions in the field of new energy vehicles.

[0006] In a first aspect of the present invention, a dual mechanical port permanent magnet motor is provided, the dual mechanical port permanent magnet motor comprising:

[0007] Four components, namely, a first armature stator, a first rotor, a composite stator and a second rotor, are coaxially arranged in sequence, and an axial air gap is provided between two adjacent components;

[0008] The composite stator includes an excitation stator and a second armature stator distributed in a direction extending from the first armature stator to the second rotor,

[0009] By controlling the current of the armature windings in the first armature stator and the second armature stator, the dual mechanical port permanent magnet motor operates in three modes: a first armature stator independent drive mode, a second armature stator independent drive mode, and a first armature stator and second armature stator combined drive mode.

[0010] In some embodiments of the present invention, when the operating environment of the dual mechanical port permanent magnet motor is a medium speed and medium load condition, in the first armature stator independent drive mode, the medium speed is greater than half of the rated speed of the dual mechanical port permanent magnet motor and less than the rated speed, and the medium load is less than 1.5 times the reference torque of the dual mechanical port permanent magnet motor and greater than half of the reference torque.

[0011] In some embodiments of the present invention, when the operating environment of the dual mechanical port permanent magnet motor is a high speed and light load condition, in the second armature stator independent drive mode, the high speed is greater than the rated speed of the dual mechanical port permanent magnet motor, and the light load is less than half of the reference torque of the dual mechanical port permanent magnet motor.

[0012] In some embodiments of the present invention, when the operating environment of the dual mechanical port permanent magnet motor is a low speed, high load condition, in the first armature-stator and the second armature-stator combined drive mode, the low speed is less than half of the rated speed of the dual mechanical port permanent magnet motor, and the high load is greater than 1.5 times the reference torque of the dual mechanical port permanent magnet motor.

[0013] In some embodiments of the present invention, the excitation stator is annular and includes m excitation cores and m NdFeB permanent magnet blocks, and the excitation core is a fan-shaped magnetic conductive block;

[0014] The NdFeB permanent magnet block is in the shape of a spoke and is embedded in the excitation core along the circumferential direction, wherein m is an integer greater than or equal to 3;

[0015] The width of the axial air gap is 0.5-1 mm.

[0016] In some embodiments of the present invention, the second armature stator includes a second armature tooth and a second armature winding wound on the second armature tooth, the second armature tooth is close to the excitation core, the second armature tooth has a radial outer end surface flush with the outer end surface of the excitation core and a radial inner end surface flush with the inner end surface of the excitation core, and the radial symmetry center line of the sector-shaped conductive magnetic block of the excitation core and the radial symmetry center line of the second armature tooth are on the same axial vertical plane.

[0017] In some embodiments of the present invention, the magnetization direction of the NdFeB permanent magnet block is tangential magnetization, and the magnetization directions of the circumferentially adjacent NdFeB permanent magnet blocks are opposite;

[0018] The pole arc width α of the NdFeB permanent magnet block, the excitation core, and the second armature tooth o , α p , α i With α o <α i <α p .

[0019] In some embodiments of the present invention, the first armature stator comprises:

[0020] A first stator armature core, the first stator armature core comprising a first armature yoke, first armature teeth and excitation teeth, wherein the first armature teeth and the excitation teeth are equal in number and are alternately arranged along a circumferential direction on the first armature yoke; and

[0021] The first stator winding includes a first armature winding wound on the first armature tooth and an excitation winding wound on the excitation tooth.

[0022] In some embodiments of the present invention, the first rotor is composed of k salient pole magnetic conductive blocks, the k salient pole magnetic conductive blocks are circumferentially separated and arranged equidistantly, and two adjacent magnetic conductive blocks are connected by non-magnetic conductive materials, wherein k is an integer greater than 3;

[0023] The second rotor includes a rotor yoke in an annular shape and j salient pole rotor teeth protruding from the rotor yoke, wherein the outer end surface of the salient pole rotor tooth is flush with the outer end surface of the rotor yoke, and the inner end surface of the salient pole rotor tooth is flush with the inner end surface of the rotor yoke, wherein j is an integer greater than 3.

[0024] In some embodiments of the present invention, the permanent magnetic flux path generated by the NdFeB permanent magnets in the composite stator includes a permanent magnetic flux path a and a permanent magnetic flux path b, wherein

[0025] The path of the permanent magnetic flux path a is as follows: starting from the NdFeB permanent magnet block, passing through the excitation core, the first rotor, the first armature tooth, the first armature yoke, the excitation tooth, the first rotor, the excitation core, and finally returning to the NdFeB permanent magnet block;

[0026] The path of the permanent magnet flux path b is as follows: starting from the NdFeB permanent magnet block, it passes through the excitation core, the second armature tooth, the salient pole rotor tooth, the rotor yoke, the salient pole rotor tooth, the second armature tooth, the excitation core and finally returns to the NdFeB permanent magnet block.

[0027] In a second aspect of the present invention, a torque distribution method for the above-mentioned dual mechanical port permanent magnet motor is provided, and the torque distribution method comprises:

[0028] A three-phase alternating current is applied to the first armature winding in the first armature stator separately, and the three-phase alternating current interacts with the outer air gap magnetic field, so that the first rotor outputs torque and is in a first armature stator independent driving mode;

[0029] A three-phase alternating current is applied to the second armature winding in the second armature stator separately, and the three-phase alternating current interacts with the inner air gap magnetic field, so that the second rotor outputs torque and is in a second armature stator independent driving mode;

[0030] By applying three-phase alternating current to the first armature winding and the second armature winding at the same time, the three-phase alternating current passed into the first armature winding and the second armature winding interact with the outer air gap magnetic field and the inner air gap magnetic field respectively, so that the output torque of the first rotor and the second rotor are superimposed and are in the first armature stator and the second armature stator combined driving mode.

[0031] In some embodiments of the present invention, the rated speed of the dual mechanical port permanent magnet motor is n rated , rated current is i qrated , reference torque T ref for ψ pm1 is the permanent magnet excitation flux of the first stator; k is the number of salient pole magnetic blocks in the first rotor, which is an integer greater than or equal to 3.

[0032] In some embodiments of the present invention, the operating condition of the dual mechanical port permanent magnet motor is high speed n>n rated , small load T<0.5T ref The dual mechanical port permanent magnet motor operates in the second armature stator independent drive mode.

[0033] In some embodiments of the present invention, the output torques of the first rotor and the second rotor are respectively The output torque T of the dual mechanical port permanent magnet motor e It can be expressed as:

[0034]

[0035] In the formula, ψ pm2 is the permanent magnet excitation flux of the second stator, i q2 is the quadrature-axis current passed through the second armature winding 4 - 4 , j is the number of salient-pole rotor teeth of the second rotor, and is an integer greater than 3.

[0036] The AC and DC axis currents flowing through the first armature winding in the first rotor are represented by i d1 =i q1 =0,

[0037] The AC and DC axis currents flowing through the second armature winding in the second rotor are expressed as j is the number of salient pole rotor teeth of the second rotor, an integer greater than 3, ψ pm2 is the permanent magnet excitation flux of the second stator.

[0038] In some embodiments of the present invention, the operating condition of the dual mechanical port permanent magnet motor is medium speed 0.5n rated <n<n rated , medium load 0.5T ref <T<1.5T ref When the dual mechanical port permanent magnet motor operates in the first armature stator independent drive mode.

[0039] In some embodiments of the present invention, the output torques of the first rotor and the second rotor are respectively Output torque T of permanent magnet motor e It can be expressed as

[0040]

[0041] In the formula, ψ pm1 is the first stator permanent magnet excitation flux, L f is the inductance of the first stator excitation winding, i f is the DC current flowing into the first stator excitation winding, i q1 is the quadrature-axis current passed through the first armature winding, k is the number of salient-pole magnetic blocks in the first rotor, and is an integer greater than or equal to 3.

[0042] The motor output torque T e Lower than the reference torque T ref When the first armature winding is connected to the AC and DC axis current, the AC and DC axis currents are expressed as

[0043] The AC and DC axis currents flowing through the second armature winding are represented by i d2 =i q2 =0;

[0044] The motor output torque T e Higher than the reference torque T ref When the first armature winding is connected to the AC and DC axis current, the AC and DC axis currents are expressed as

[0045] The excitation current passed through the excitation winding is expressed as

[0046] The AC and DC axis currents flowing through the second armature winding are represented by i d2 =i q2 =0.

[0047] In some embodiments of the present invention, the operating environment of the dual mechanical port permanent magnet motor is low speed n<0.5n rated , Large load T>1.5T ref When the condition is met, the dual mechanical port permanent magnet motor operates in a first armature-stator and a second armature-stator combined driving mode.

[0048] In some embodiments of the present invention, the total output torque of the first rotor and the second rotor is

[0049]

[0050] In some embodiments of the present invention, the control target is to minimize the total copper loss of the motor, and the optimal torque distribution strategy for the first rotor and the second rotor is:

[0051] In some embodiments of the present invention, the AC and DC axis currents passed through the first armature winding under the optimal torque distribution strategy are expressed as: The AC and DC axis currents flowing through the second armature winding are expressed as

[0052] A stator composite dual mechanical port permanent magnet motor and a torque distribution method thereof according to an embodiment of the present invention have at least one of the following advantages:

[0053] 1. The dual mechanical port permanent magnet motor of the present invention utilizes the composite stator characteristics and is matched with a dual rotor structure. By controlling the current of the armature windings of the first armature stator and the second armature stator respectively, the output power of the dual mechanical ports can be distributed, thereby meeting different working conditions and making the output efficiency and output torque of the permanent magnet motor reach the optimal value.

[0054] 2. The first rotor and the second rotor in the dual mechanical port permanent magnet motor of the present invention are not provided with permanent magnets and windings, thereby avoiding the difficulty in heat dissipation of the rotor windings that may be caused by the rotor excitation type motor and the demagnetization problem that may be caused by the permanent magnets on the rotor side at high temperatures, thereby improving the reliability of the permanent magnet motor.

[0055] 3. The permanent magnetic flux generated by the composite stator NdFeB permanent magnet block shared by the first armature stator and the second armature stator in the dual mechanical port permanent magnet motor of the present invention effectively improves the permanent magnet utilization rate of this type of motor and reduces the leakage flux at the end of the permanent magnet.

[0056] 4. In the dual mechanical port permanent magnet motor of the present invention, excitation teeth are added to the first stator. By passing current through the excitation winding, the magnetic field of the motor can be weakened, thereby compensating for the defect that the magnetic field of the permanent magnet motor cannot be adjusted; when the inner stator permanent magnet loses magnetism, the existence of the excitation winding can establish an air gap magnetic field to ensure the normal operation of the motor.

[0057] 5. The dual mechanical port permanent magnet motor of the present invention can change the operating mode of the motor by changing the armature current applied by the first and second armature windings, thereby meeting the requirements of different working conditions, so that the motor output torque and efficiency are optimized. At the same time, by adding an excitation winding, the air gap magnetic field of the motor can be adjusted, thereby enhancing the weak magnetic capability and torque output capability of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of the preferred embodiments in conjunction with the accompanying drawings, in which:

[0059] Figure 1 It is an exploded schematic diagram of a stator composite type dual mechanical port permanent magnet motor according to an embodiment of the present invention;

[0060] Figure 2 for Figure 1 A schematic diagram of the structure of the first armature stator;

[0061] Figure 3 for Figure 1 A schematic diagram of the structure of the first armature winding and the excitation winding;

[0062] Figure 4 for Figure 1 Schematic diagram of the structure of the composite stator;

[0063] Figure 5 for Figure 1 A schematic diagram of the structure of the second rotor;

[0064] Figure 6 for Figure 1 The magnetic circuit schematic diagram of the stator composite type dual mechanical port permanent magnet motor is shown. DETAILED DESCRIPTION

[0065] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0066] See also Figure 1 , shows a dual mechanical port permanent magnet motor, for example a stator composite type, according to an embodiment of the present invention.

[0067] The permanent magnet motor mainly includes four components: a first armature stator 10, a first rotor 3, a composite stator 4, and a second rotor 5. The first armature stator 1, the first rotor 3, the composite stator 4, and the second rotor 5 are coaxially arranged and arranged in the order of the first armature stator 1, the first rotor 3, the composite stator 4, and the second rotor 5. Each component is placed axially but not close to each other, and an axial air gap is left between two adjacent components. According to actual needs, the width of the axial air gap ranges from 0.5 to 1 mm.

[0068] See also Figure 2 The first armature stator 1 includes a first stator armature core and a first stator winding 2, wherein the first stator armature core includes three components: a first armature yoke 1-3, a first armature tooth 1-1, and an excitation tooth 1-2. Specifically, the number of the first armature teeth 1-1 and the excitation teeth 1-2 is equal, and the specific number can be set as needed. The two are staggered along the circumference on the first armature yoke 1-3.

[0069] See also Figure 3 The first stator winding includes two parts: a first armature winding 2-1 and an excitation winding 2-2; the first armature winding 2-1 is wound on the first armature tooth 1-1; the excitation winding 2-2 is wound on the excitation tooth 1-2.

[0070] Return to see Figure 1 The first rotor 3 is composed of k salient pole magnetic conductive blocks, and the k salient pole magnetic conductive blocks are circumferentially separated and arranged equidistantly, and two adjacent magnetic conductive blocks are connected by non-magnetic conductive materials.

[0071] See also Figure 4 The composite stator 4 is composed of two layers extending from the first armature stator to the second rotor. The first layer is an excitation stator, which is annular and includes an excitation core 4-1 and a NdFeB permanent magnet block 4-2. The excitation core 4-1 is composed of m sector-shaped magnetic conductive blocks. There are m NdFeB permanent magnet blocks 4-2, where m is an integer greater than 3, and the shape is spoke-shaped and embedded in the excitation core 4-1 along the circumferential direction.

[0072] The second layer structure of the composite stator 4 is a second armature stator, including a second armature tooth 4-3 and a second armature winding 4-4, wherein the second armature winding 4-4 ​​is wound on the second armature tooth 4-3; the second armature tooth 4-3 is arranged closely to the excitation core 4-1, and its radial outer end face is flush with the outer end face of the excitation core 4-1, and its radial inner end face is flush with the inner end face of the excitation core 4-1; the radial symmetry center line of the sector-shaped conductive magnetic block and the radial symmetry center line of the second armature tooth 4-3 are on the same axial vertical plane.

[0073] The magnetization direction of the NdFeB permanent magnet block 4-2 is tangential magnetization, and the magnetization directions of two adjacent NdFeB permanent magnet blocks 4-2 along the circumferential direction are opposite; the pole arc width α of the NdFeB permanent magnet block 4-2, the excitation core 4-1, and the second armature tooth 4-3 is o , α p , α i With α o <α i <α p .

[0074] See also Figure 5 The second rotor 5 includes a rotor yoke 5-2 and j salient pole rotor teeth 5-1 protruding from the rotor yoke, wherein the outer end surface of the salient pole rotor tooth 5-1 is flush with the outer end surface of the rotor yoke 5-2, and the inner end surface of the salient pole rotor tooth 5-1 is flush with the inner end surface of the rotor yoke 5-2; the rotor yoke 5-2 is in a circular ring shape.

[0075] In some embodiments, the control current passed through the first armature winding 2-1 is a three-phase alternating current; the control current passed through the excitation winding 2-2 is a direct current. By adjusting the magnitude and polarity of the direct current, the magnetic field of the motor can be weakened, thereby changing the torque output capacity and speed regulation range of the permanent magnet motor.

[0076] Specifically, see Figure 6 , the permanent magnetic flux paths generated by the NdFeB permanent magnet 4-2 of the first layer structure have two paths: permanent magnetic flux a and permanent magnetic flux b, wherein the path of permanent magnetic flux a is as follows: starting from the NdFeB permanent magnet block 4-2, it passes through the excitation core 4-1, the first rotor 3, the first armature tooth 1-1, the first armature yoke 1-3, the excitation tooth 1-2, the first rotor 3, the excitation core 4-1 and finally returns to the NdFeB permanent magnet block 4-2. The path of permanent magnetic flux b is as follows: starting from the NdFeB permanent magnet block 4-2, it passes through the excitation core 4-1, the second armature tooth 4-3, the salient pole rotor tooth 5-1, the rotor yoke 5-2, the salient pole rotor tooth 5-1, the second armature tooth 4-3, the excitation core 4-1 and finally returns to the NdFeB permanent magnet block 4-2.

[0077] Specifically, when the first armature winding 2-1 is added with three-phase alternating current alone, the interaction between the three-phase alternating current and the outer air gap magnetic field can enable the first rotor 3 to output torque; when the second armature winding 4-4 ​​is added with three-phase alternating current alone, the interaction between the three-phase alternating current and the inner air gap magnetic field can enable the second rotor 5 to output torque; when the first armature winding 2-1 and the second armature winding 4-4 ​​are simultaneously supplied with three-phase alternating current, the three-phase currents supplied to the first and second armature windings 2-1 and 4-4 interact with the inner and outer air gap magnetic fields respectively, and the first and second rotors 1 and 5 are connected through planetary gears, so that the motor output torque values ​​can be superimposed, thereby greatly improving the motor output torque capacity.

[0078] In another aspect of the present invention, a torque distribution method for a stator-compound dual-mechanical-port permanent magnet motor is provided. The permanent magnet motor mainly operates in the following three modes.

[0079] 1) Mode 1: Second armature stator independent drive mode

[0080] When the operating environment of the drive motor is high speed and light load, the stator composite dual mechanical port permanent magnet motor operates in the second armature stator independent drive mode. In this mode, only the second armature stator operates alone, and only the three-phase alternating current is applied to the second armature winding 4-4. Since the salient pole ratio of the permanent magnet motor is small, i d = 0 control to achieve the torque output of the permanent magnet motor. The output torques of the first rotor 1 and the second rotor 5 are respectively

[0081]

[0082] At this time, the output torque T of the permanent magnet motor e It can be expressed as

[0083]

[0084] In the formula, ψ pm2 is the permanent magnet excitation flux of the second stator 5, i q2 is the quadrature-axis current passed through the second armature winding 4 - 4 , j is the number of the salient-pole rotor teeth 5 - 1 of the second rotor 5 , and is an integer greater than 3.

[0085] According to formula (2), the AC and DC axis currents flowing through the first armature winding 2-1 and the second armature winding 4-4 ​​of the permanent magnet motor can be expressed as:

[0086]

[0087] 2) Mode 2: First armature stator independent drive mode

[0088] When the operating environment of the drive motor is medium speed and medium load, the stator composite dual mechanical port permanent magnet motor operates in the first armature stator independent drive mode. In this mode, only the first armature stator operates alone, and only the three-phase alternating current is applied to the first armature winding 2-1, and the direct current is passed through the excitation winding to assist in magnetic regulation. The output torques of the first rotor 1 and the second rotor 5 are respectively

[0089]

[0090] The output torque T of the permanent magnet motor e It can be expressed as

[0091]

[0092] In the formula, ψ pm1 is the first stator permanent magnet excitation flux, L f is the inductance of the first stator excitation winding, i f is the DC current flowing into the first stator excitation winding, i q1 is the quadrature-axis current passed through the first armature winding 2-1, k is the number of salient-pole magnetic blocks in the first rotor, and is an integer greater than or equal to 3.

[0093] Reference torque value T ref It can be expressed as

[0094]

[0095] According to formula (5), the AC and DC axis currents flowing through the first armature winding 2-1 and the second armature winding 4-4 ​​of the motor can be expressed as

[0096]

[0097] In the formula, i qrated is the rated q-axis current value of the first armature winding. q1 The quadrature axis current introduced into the first armature winding 2-1 reaches the rated current value i qrated When the output torque of the permanent magnet motor still fails to meet the required load requirement, it is necessary to inject additional DC current into the excitation winding, and the current size is shown in formula (8).

[0098] 3) Mode 3: Combined drive mode of the first armature stator and the second armature stator

[0099] When the operating environment of the drive motor is low speed and high load, the stator composite dual mechanical port permanent magnet motor operates in the first and second armature stator combined drive mode. In this mode, the first and second armature stators operate in coordination, and three-phase alternating current is applied to the first armature winding and the second armature winding. The output torque T of the motor e It can be expressed as

[0100]

[0101] In order to maximize the torque under the unit current of the motor, the minimum total copper loss of the motor is selected as the control target.

[0102]

[0103] According to formula (10), the Lagrange equation is constructed

[0104]

[0105] For the Lagrange equation (11) with respect to id1 ,i q1 ,i d2 ,i q2 ,λ respectively, we can get

[0106]

[0107] By solving equation (12), we can get i d1 ,i q1 ,i d2 ,i q2 The relationship

[0108]

[0109] Substituting equation (13) into equation (9) can obtain the optimal torque distribution strategy:

[0110]

[0111] Under this torque distribution strategy, the AC and DC axis current i of the first armature winding 2-1 is d1 ,i q1 , the AC and DC axis current i of the second armature winding 4-4 d2 ,i q2 They can be expressed as

[0112]

[0113] A stator composite dual mechanical port permanent magnet motor and a torque distribution method thereof according to an embodiment of the present invention have at least one of the following advantages:

[0114] 1. The dual mechanical port permanent magnet motor of the present invention utilizes the composite stator characteristics and is matched with a dual rotor structure. By controlling the current of the armature windings of the first armature stator and the second armature stator respectively, the output power of the dual mechanical ports can be distributed, thereby meeting different working conditions and making the output efficiency and output torque of the permanent magnet motor reach the optimal value.

[0115] 2. The first rotor and the second rotor in the dual mechanical port permanent magnet motor of the present invention are not provided with permanent magnets and windings, thereby avoiding the difficulty in heat dissipation of the rotor windings that may be caused by the rotor excitation type motor and the demagnetization problem that may be caused by the permanent magnets on the rotor side at high temperatures, thereby improving the reliability of the permanent magnet motor.

[0116] 3. The permanent magnetic flux generated by the composite stator NdFeB permanent magnet block shared by the first armature stator and the second armature stator in the dual mechanical port permanent magnet motor of the present invention effectively improves the permanent magnet utilization rate of this type of motor and reduces the leakage flux at the end of the permanent magnet.

[0117] 4. In the dual mechanical port permanent magnet motor of the present invention, excitation teeth are added to the first stator. By passing current through the excitation winding, the magnetic field of the motor can be weakened, thereby compensating for the defect that the magnetic field of the permanent magnet motor cannot be adjusted; when the inner stator permanent magnet loses magnetism, the existence of the excitation winding can establish an air gap magnetic field to ensure the normal operation of the motor.

[0118] 5. The dual mechanical port permanent magnet motor of the present invention can change the operating mode of the motor by changing the armature current applied by the first and second armature windings, thereby meeting the requirements of different working conditions, so that the motor output torque and efficiency are optimized. At the same time, by adding an excitation winding, the air gap magnetic field of the motor can be adjusted, thereby enhancing the weak magnetic capability and torque output capability of the motor.

[0119] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A stator composite dual mechanical port permanent magnet motor, characterized in that: The dual mechanical port permanent magnet motor comprises: Four components, namely, a first armature stator, a first rotor, a composite stator and a second rotor, are coaxially arranged in sequence, and an axial air gap is provided between two adjacent components; The composite stator includes an excitation stator and a second armature stator distributed in a direction extending from the first armature stator to the second rotor, By controlling the current of the armature windings in the first armature stator and the second armature stator, the dual mechanical port permanent magnet motor operates in three modes: a first armature stator independent drive mode, a second armature stator independent drive mode, and a first armature stator and second armature stator combined drive mode.

2. The dual mechanical port permanent magnet motor according to claim 1, characterized in that: When the operating environment of the dual mechanical port permanent magnet motor is a medium speed and medium load condition, in the first armature stator independent drive mode, the medium speed is greater than half of the rated speed of the dual mechanical port permanent magnet motor and less than the rated speed, and the medium load is less than 1.5 times the reference torque of the dual mechanical port permanent magnet motor and greater than half of the reference torque.

3. The dual mechanical port permanent magnet motor according to claim 1, characterized in that: When the operating environment of the dual mechanical port permanent magnet motor is high speed and light load conditions, in the second armature stator independent drive mode, the high speed is greater than the rated speed of the dual mechanical port permanent magnet motor, and the light load is less than half of the reference torque of the dual mechanical port permanent magnet motor.

4. The dual mechanical port permanent magnet motor according to claim 1, characterized in that: When the operating environment of the dual mechanical port permanent magnet motor is a low speed, high load condition, in the first armature-stator and the second armature-stator combined drive mode, the low speed is less than half of the rated speed of the dual mechanical port permanent magnet motor, and the high load is greater than 1.5 times the reference torque of the dual mechanical port permanent magnet motor.

5. The dual mechanical port permanent magnet motor according to claim 1, characterized in that: The excitation stator is annular and includes m excitation cores and m NdFeB permanent magnet blocks, wherein the excitation core is a fan-shaped magnetic conductive block; The NdFeB permanent magnet block is in the shape of a spoke and is embedded in the excitation core along the circumferential direction, wherein m is an integer greater than or equal to 3; The width of the axial air gap is 0.5-1 mm.

6. The dual mechanical port permanent magnet motor according to claim 5, characterized in that: The second armature stator includes a second armature tooth and a second armature winding wound on the second armature tooth. The second armature tooth is arranged closely to the excitation core. The second armature tooth has a radial outer end surface flush with the outer end surface of the excitation core and a radial inner end surface flush with the inner end surface of the excitation core. The radial symmetry center line of the sector-shaped conductive magnetic block of the excitation core and the radial symmetry center line of the second armature tooth are on the same axial vertical plane.

7. The dual mechanical port permanent magnet motor according to claim 6, characterized in that: The magnetization direction of the NdFeB permanent magnet block is tangential magnetization, and the magnetization directions of the adjacent NdFeB permanent magnet blocks along the circumferential direction are opposite; The pole arc width α of the NdFeB permanent magnet block, the excitation core, and the second armature tooth o , α p , α i With α o <α i <α p .

8. The dual mechanical port permanent magnet motor according to any one of claims 1 to 7, characterized in that: The first armature stator comprises: A first stator armature core, the first stator armature core comprising a first armature yoke, first armature teeth and excitation teeth, wherein the first armature teeth and the excitation teeth are equal in number and are alternately arranged along a circumferential direction on the first armature yoke; and The first stator winding comprises a first armature winding wound on the first armature tooth and an excitation winding wound on the excitation tooth, and the control current flowing into the excitation winding is a direct current.

9. The dual mechanical port permanent magnet motor according to claim 8, characterized in that: The first rotor is composed of k salient pole magnetic conductive blocks, the k salient pole magnetic conductive blocks are circumferentially separated and arranged equidistantly, and two adjacent magnetic conductive blocks are connected by non-magnetic conductive materials, wherein k is an integer greater than 3; The second rotor includes a rotor yoke in an annular shape and j salient pole rotor teeth protruding from the rotor yoke, wherein the outer end surface of the salient pole rotor tooth is flush with the outer end surface of the rotor yoke, and the inner end surface of the salient pole rotor tooth is flush with the inner end surface of the rotor yoke, wherein j is an integer greater than 3.

10. The dual mechanical port permanent magnet motor according to claim 9, characterized in that: The permanent magnetic flux path generated by the NdFeB permanent magnets in the composite stator includes a permanent magnetic flux path a and a permanent magnetic flux path b, wherein The path of the permanent magnetic flux path a is as follows: starting from the NdFeB permanent magnet block, passing through the excitation core, the first rotor, the first armature tooth, the first armature yoke, the excitation tooth, the first rotor, the excitation core, and finally returning to the NdFeB permanent magnet block; The path of the permanent magnet flux path b is as follows: starting from the NdFeB permanent magnet block, it passes through the excitation core, the second armature tooth, the salient pole rotor tooth, the rotor yoke, the salient pole rotor tooth, the second armature tooth, the excitation core and finally returns to the NdFeB permanent magnet block.

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