Hybrid excited axial brushless motor and power generation method thereof

Abstract

Provided in the present invention are a hybrid excited axial brushless motor and a power generation method thereof. The hybrid excited axial brushless motor comprises a housing and a rotating shaft rotatably fixed in the housing. Seven parts, i.e. a first exciter stator, a first magnetic shunt ring rotor, a first permanent magnet rotor, an armature stator, a second permanent magnet rotor, a second magnetic shunt ring rotor and a second exciter stator are successively mounted in the housing in the axial direction, air gaps being provided between every two adjacent parts. The first permanent magnet rotor and the second permanent magnet rotor are symmetrically arranged and are both rotatably fixed to the rotating shaft; the first magnetic shunt ring rotor and the second magnetic shunt ring rotor are symmetrically arranged and are both fixedly connected to the rotating shaft; the first exciter stator and the second exciter stator are symmetrically arranged and are both fixedly connected to the housing. By means of an armature stator support, the armature stator is fixedly connected to the housing. The present invention achieves brushless hybrid excitation, and increases the power density and the power generation capacity of motors.

Description

A hybrid excitation axial brushless motor and power generation method thereof Technical Field

[0001] The present invention relates to the technical field of axial motors, and in particular to a hybrid excitation axial brushless motor and a power generation method thereof. Background Art

[0002] With the increasing energy crisis and environmental awareness, the scale of hybrid vehicles, hybrid drones and wind power generation has gradually increased. Due to its own advantages, hybrid excitation axial flux motors are becoming more and more widely used in hybrid drive and wind power generation fields, but their low power factor and efficiency problems have also become prominent.

[0003] First, the rotor in a hybrid-excitation axial flux motor currently typically uses a single rotor structure, such as a wound rotor, a squirrel cage rotor, or a permanent magnet rotor. Axial induction motors using a single wound rotor or squirrel cage rotor have low efficiency and power factor. Furthermore, wound rotors require brushes and slip rings, reducing operational reliability. Permanent magnet synchronous motors using a single permanent magnet rotor have an unadjustable magnetic field, making them incapable of flexible magnetic field adjustment under varying speed conditions.

[0004] Secondly, the hybrid excitation axial flux motor structures in the existing technology are mostly flux switching motors and brushed induction motors. Because flux switching motors generally use a salient pole structure, and the permanent magnets and armature windings in the motor are both located on the stator side, the permanent magnets and armature windings compete for space, limiting the space utilization and torque density of the hybrid excitation axial flux switching motor. Hybrid excitation axial brushed induction motors, whether using permanent magnet excitation or direct current for hybrid excitation, although the motor efficiency is improved, the motor structure is too complex.

[0005] In addition, existing hybrid excitation axial flux motors usually have axial unbalanced magnetic pull, which causes large vibrations during motor operation.

[0006] In summary, the power density and torque density of hybrid-excitation axial flux motors still need to be further improved. The challenge of achieving brushless AC excitation remains unresolved. Furthermore, existing permanent magnet brushless motors also face challenges in magnetic field regulation and power generation efficiency. These issues all impact the motor's power factor and efficiency.

[0007] Summary of the Invention

[0008] To solve the problems existing in the background technology, the present invention proposes a hybrid excitation axial brushless motor, comprising a housing and a rotating shaft rotatably fixed in the housing, wherein seven components, namely a first excitation stator, a first magnetic ring rotor, a first permanent magnet rotor, an armature stator, a second permanent magnet rotor, a second magnetic ring rotor and a second excitation stator, are installed in sequence along the axial direction in the housing, with an air gap provided between each adjacent component, the first permanent magnet rotor and the second permanent magnet rotor are symmetrically arranged and both are rotatably fixed to the rotating shaft, the first magnetic ring rotor and the second magnetic ring rotor are symmetrically arranged and both are fixedly connected to the rotating shaft, the first excitation stator and the second excitation stator are symmetrically arranged and both are fixedly connected to the housing, and the armature stator is fixedly connected to the housing via an armature stator bracket;

[0009] The number of magnetic poles of the first excitation stator and the second excitation stator is p, and the number of magnetic poles of the armature stator is q; the first magnetic tuning ring rotor and the second magnetic tuning ring rotor both include magnetic resistance units, and the number of magnetic resistance units is p+q; p and q are both integers, and p and q are not equal.

[0010] Preferably, the first excitation stator and the second excitation stator are both annular and have slots, and the first excitation stator and the second excitation stator are respectively embedded with the first excitation stator winding and the second excitation stator winding in the slots, and the first excitation stator winding and the second excitation stator winding form a magnetic field with a pole number p when energized.

[0011] Preferably, the first permanent magnet rotor and the second permanent magnet rotor both include a permanent magnet rotor disk and a plurality of permanent magnets, the permanent magnets are evenly distributed on the circumference of one side of the permanent magnet rotor disk, the permanent magnets are all axially magnetized neodymium iron boron and are placed at intervals according to the magnetization polarity N and S, and the number of permanent magnet poles is q.

[0012] Preferably, the first magnetic tuning ring rotor and the second magnetic tuning ring rotor also include a magnetic tuning ring rotor disk, and the magnetic resistance unit includes a plurality of magnetic conductive blocks and a plurality of non-magnetic conductive blocks, the magnetic conductive blocks and the non-magnetic conductive blocks are installed on the magnetic tuning ring rotor disk, and the magnetic conductive blocks and the non-magnetic conductive blocks are alternately arranged along the magnetic tuning ring rotor disk.

[0013] Preferably, the armature stator includes a stator core, a magnetic separator, a first armature stator winding and a second armature stator winding. The stator core is slotted on both sides, and the first armature stator winding and the second armature stator winding are respectively installed in the slots on both sides of the stator core. When the first armature stator winding and the second armature stator winding are energized, a magnetic field with a pole number p will be formed. The magnetic separator is arranged on the stator core between the first armature stator winding and the second armature stator winding.

[0014] Preferably, the first armature stator winding and the second armature stator winding located in the stator core slots are both AC windings, and the magnetic fields generated by the first armature stator winding and the second armature stator winding are uncoupled, and the magnetic spacer disk is made of non-magnetic material.

[0015] Preferably, the first permanent magnet rotor and the second permanent magnet rotor are rotatably fixed on the rotating shaft via permanent magnet rotor bearings respectively.

[0016] A method for generating electricity using a hybrid excitation axial brushless motor:

[0017] The first excitation stator, the first magnetic ring rotor, the first permanent magnet rotor and the first armature stator winding form a first working unit, and the second excitation stator, the second magnetic ring rotor, the second permanent magnet rotor and the second armature stator winding form a second working unit. The first working unit and the second working unit operate simultaneously and have the same operating principle.

[0018] Taking the first working unit as an example, the external power component drives the rotating shaft to rotate, and the rotating shaft drives the first magnetic tuning ring rotor to rotate. At this time, the number of pole pairs of the AC magnetic field generated by the AC excitation current passing through the first excitation stator winding is p. The magnetic field is modulated by the first magnetic tuning ring rotor to modulate the p-pole and q-pole magnetic fields. The modulated q-pole magnetic field interacts with the first armature stator winding, and a q-pole AC electromotive force is induced in the first armature stator winding; at the same time, the first permanent magnet rotor is forced to rotate in the changing magnetic field, and the rotating first permanent magnet rotor cuts the modulated AC magnetic field, which will also induce a q-pole AC electromotive force in the first armature stator winding.

[0019] The beneficial effects of the present invention are:

[0020] 1. The first excitation stator, the second excitation stator, the first magnetic tuning ring rotor and the second magnetic tuning ring rotor structure adopted in the present invention realize the brushless design of the hybrid excitation axial motor of the present invention, solve the technical problem that the brushes and slip rings of the AC brush motor will generate sparks, and the sparks will cause the motor to have poor reliability and high failure rate, thereby improving the stable operation capability of the motor.

[0021] 2. The present invention is symmetrical about the armature stator in overall structure, balancing the axial magnetic pull of the stator and rotor, thereby achieving the purpose of reducing vibration and noise.

[0022] 3. The present invention adopts a hybrid excitation structure of the same axial AC and permanent magnet excitation. The first excitation stator and the second excitation stator are AC excitation, the first permanent magnet rotor and the second permanent magnet rotor are permanent magnet excitation, and the armature stator includes two independent armature stator windings, which is equivalent to the performance of two brushless axial motors combined, significantly improving the motor power density and power generation.

[0023] 4. The AC and permanent magnet hybrid excitation of the present invention improves the operating efficiency of the motor and also improves the flexibility of magnetic field regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic diagram of the overall structure of the present invention;

[0025] FIG2 is a schematic diagram of the armature stator structure of the present invention;

[0026] FIG3 is a schematic diagram of the structure of the excitation stator of the present invention;

[0027] FIG4 is a schematic diagram of the structure of the permanent magnet rotor of the present invention;

[0028] FIG5 is a schematic diagram of the structure of the magnetic ring rotor of the present invention;

[0029] FIG6 is a schematic diagram of the overall structure of Example 2 of the present invention;

[0030] FIG7 is a schematic diagram of the overall structure of Example 3 of the present invention.

[0031] Reference numerals in the figure: 1, housing; 2, first end cover; 3, first excitation stator; 4, first excitation stator winding; 5, first magnetic ring rotor; 6, first permanent magnet rotor; 7, second end cover; 8, second excitation stator; 9, second excitation stator winding; 10, permanent magnet rotor bearing; 11, second magnetic ring rotor; 12, second permanent magnet rotor; 13, permanent magnet; 14, armature stator; 15, magnetic spacer; 16, Armature stator bracket; 17. Rotating shaft bearing; 18. Rotating shaft; 19. First armature stator winding; 20. Second armature stator winding; 21. Permanent magnet rotor disk; 22. Magnetic ring rotor disk; 23. Reluctance unit; 24. Magnetic conductive block; 25. Non-magnetic conductive block; 26. Armature stator rectifier inverter device; 27. Excitation stator rectifier inverter device; 28. Battery; 29. ​​Dual PWM converter; 30. Power grid. DETAILED DESCRIPTION

[0032] In order to make the present invention clearer and more understandable, the technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the given embodiments are only two implementation methods and do not represent all embodiments.

[0033] Example 1:

[0034] In conjunction with Figures 1-6, the present invention proposes a hybrid excitation axial brushless motor, comprising a housing 1 and a rotating shaft 18 rotatably fixed in the housing 1. Specifically, a first end cover 2 and a second end cover 7 are provided at both ends of the housing 1. One end of the rotating shaft 18 is rotatably connected to the first end cover 2 through a rotating shaft bearing 17, and the other end of the rotating shaft 18 is rotatably connected to the second end cover 7 through another rotating shaft bearing 17. The housing 1 is provided with a first excitation stator 3, a first magnetic ring rotor 5, a first permanent magnet rotor 6, an armature stator 14, a second permanent magnet stator 15, and a second excitation stator 16. The rotor 12, the second magnetic ring rotor 11, and the second excitation stator 8 are seven components, with air gaps between adjacent components. The first permanent magnet rotor 6 and the second permanent magnet rotor 12 are symmetrically arranged and both are rotatably fixed to the rotating shaft 18. The first magnetic ring rotor 5 and the second magnetic ring rotor 11 are symmetrically arranged and both are fixedly connected to the rotating shaft 18. The first excitation stator 3 and the second excitation stator 8 are symmetrically arranged and both are fixedly connected to the housing 1. The armature stator 14 is fixedly connected to the housing 1 via the armature stator bracket 16.

[0035] The number of magnetic poles of the first excitation stator 3 and the second excitation stator 8 is p, and the number of magnetic poles of the armature stator 14 is q; the first magnetic tuning ring rotor 5 and the second magnetic tuning ring rotor 11 both include magnetic resistance units 23, and the number of magnetic resistance units 23 is p+q; p and q are both integers, and p and q are not equal.

[0036] The center lines of the eight components, namely, the rotating shaft 18 , the first excitation stator 3 , the first magnetic ring rotor 5 , the first permanent magnet rotor 6 , the armature stator 14 , the second permanent magnet rotor 12 , the second magnetic ring rotor 11 and the second excitation stator, are on the same straight line.

[0037] Specifically, the first excitation stator 3 and the second excitation stator 8 are both annular and have slots. The first excitation stator 3 and the second excitation stator 8 respectively have the first excitation stator winding 4 and the second excitation stator winding 9 embedded in the slots. When the first excitation stator winding 4 and the second excitation stator winding 9 are energized, a magnetic field with a pole number p is formed.

[0038] Specifically, the first permanent magnet rotor 6 and the second permanent magnet rotor 12 each include a permanent magnet rotor disk 21 and a plurality of permanent magnets 13. The permanent magnets 13 are evenly distributed on the circumference of one side of the permanent magnet rotor disk 21. The permanent magnets 13 are all axially magnetized neodymium iron boron and are spaced apart according to the magnetization polarity N and S. The number of poles of the permanent magnets 13 is q.

[0039] Specifically, the first magnetic tuning ring rotor 5 and the second magnetic tuning ring rotor 11 also include a magnetic tuning ring rotor disk 22, and the magnetic resistance unit 23 includes a plurality of magnetic conductive blocks 24 and a plurality of non-magnetic conductive blocks 25. The magnetic conductive blocks 24 and the non-magnetic conductive blocks 25 are installed on the magnetic tuning ring rotor disk 22, and the magnetic conductive blocks 24 and the non-magnetic conductive blocks 24 are alternately arranged along the magnetic tuning ring rotor disk 22.

[0040] Specifically, the armature stator 14 includes a stator core, a magnetic isolation disk 15, a first armature stator winding 19 and a second armature stator winding 20. The stator core is slotted on both sides, and the first armature stator winding 19 and the second armature stator winding 20 are respectively installed in the slots on both sides of the stator core. When the first armature stator winding 19 and the second armature stator winding 20 are energized, a magnetic field with a pole number p will be formed. The magnetic isolation disk 15 is arranged on the stator core between the first armature stator winding 19 and the second armature stator winding 20.

[0041] Specifically, the first armature stator winding 19 and the second armature stator winding 20 located in the stator core slots are both AC windings, and the magnetic fields generated by the first armature stator winding 19 and the second armature stator winding 20 are not coupled, and the magnetic separator 15 is made of non-magnetic material.

[0042] Specifically, the first permanent magnet rotor 6 and the second permanent magnet rotor 12 are respectively rotatably fixed on the rotating shaft 18 through the permanent magnet rotor bearings 10 , and can freely rotate around the rotating shaft 18 through the permanent magnet rotor bearings 10 .

[0043] A hybrid excitation axial brushless motor power generation method: the first excitation stator 4, the first magnetic ring rotor 5, the first permanent magnet rotor 6 and the first armature stator winding 19 form a first working unit, and the second excitation stator 8, the second magnetic ring rotor 11, the second permanent magnet rotor 12 and the second armature stator winding 20 form a second working unit. The first working unit and the second working unit operate simultaneously and have the same operating principle.

[0044] Taking the first working unit as an example, the external power component drives the rotating shaft 18 to rotate. The external power component is a driving device such as an internal combustion engine or a wind turbine. The rotating shaft 18 drives the first magnetic tuning ring rotor 5 to rotate. At this time, the number of pole pairs of the AC magnetic field generated by the AC excitation current passing through the first excitation stator winding 4 is p. The magnetic field is modulated by the first magnetic tuning ring rotor 5 to modulate the p-pole and q-pole magnetic fields. The modulated q-pole magnetic field interacts with the first armature stator winding 19, and a q-pole AC electromotive force is induced in the first armature stator winding 19; at the same time, the first permanent magnet rotor 6 is forced to rotate in the changing magnetic field, and the rotating first permanent magnet rotor 6 cuts the modulated AC magnetic field, which will also induce a q-pole AC electromotive force in the first armature stator winding 19.

[0045] Example 2:

[0046] In conjunction with Figure 6, taking the first working unit as an example, when the hybrid excitation axial brushless motor is used as a hybrid drive system for power generation, the first armature stator winding 19 is connected to the battery 28 through the armature stator rectifier inverter device 26, and the first excitation stator winding 4 is connected to the battery 28 through the excitation stator rectifier inverter device 27. When the motor shaft 18 is subjected to the driving torque of the external power components of the prime mover, the current in the excitation stator rectifier inverter device 27 can be adjusted to ensure that the first armature stator winding 19 outputs AC power.

[0047] The external motive force driving torque and the current in the first excitation stator 3 cooperate with each other to ensure that the first armature stator winding 19 can output a stable electromotive force.

[0048] Example 3:

[0049] In conjunction with Figure 7, taking the first working unit as an example, when the hybrid excitation axial brushless motor is operated as a variable speed constant frequency wind power generator, the first armature stator winding 19 is directly connected to the power grid 30, and the first excitation stator winding 4 is connected to the power grid 30 through a dual PWM converter 29. In order to ensure variable speed constant frequency operation, when the wind speed changes and the generator speed changes, the frequency of the current of the first excitation stator winding 4 can be controlled to keep the frequency of the first armature stator winding 19 constant. Specifically, when the generator speed is less than the synchronous speed, that is, it is in a subsynchronous state, the direction of the rotating magnetic field generated by the first excitation stator 3 is the same as the direction of the speed. At this time, the first excitation stator 3 absorbs slip power from the power grid 30 through the dual PWM inverter 29; when the generator speed is greater than the synchronous speed, that is, it is in a supersynchronous state, the direction of the rotating magnetic field generated by the first excitation stator 3 is opposite to the direction of the speed. At this time, the first excitation stator winding 4 feeds slip power to the power grid 30 through the dual PWM inverter 29; when the generator speed is equal to the synchronous speed, that is, it is in a synchronous state, at this time, the dual PWM inverter 29 provides DC excitation to the first excitation stator 3, which is equivalent to the operation of a synchronous generator. In the above three operating states, the excitation method of the first excitation stator 3 is to realize brushless doubly fed excitation after magnetic modulation by the first magnetic modulation ring rotor 5.

[0050] It can be seen that when the wind turbine is connected to the grid, the present invention can realize brushless double-fed variable speed constant frequency power generation.

[0051] The above embodiments merely illustrate the basic principles and features of the present invention and are not intended to be limiting. It should be understood that various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and such changes and modifications are intended to fall within the scope of the present invention as claimed. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hybrid excitation axial brushless motor, comprising a housing (1) and a rotating shaft (18) rotatably fixed in the housing (1), characterized in that: The casing (1) is provided with seven components, namely, a first excitation stator (3), a first magnetic ring rotor (5), a first permanent magnet rotor (6), an armature stator (14), a second permanent magnet rotor (12), a second magnetic ring rotor (11) and a second excitation stator (8), in sequence along the axial direction. An air gap is provided between two adjacent components. The first permanent magnet rotor (6) and the second permanent magnet rotor (12) are symmetrically arranged and both are rotatably fixed on the rotating shaft (18). The first magnetic ring rotor (5) and the second magnetic ring rotor (11) are symmetrically arranged and both are fixedly connected to the rotating shaft (18). The first excitation stator (3) and the second excitation stator (8) are symmetrically arranged and both are fixedly connected to the casing (1). The armature stator (14) is fixedly connected to the casing (1) via an armature stator bracket (16). The number of magnetic poles of the first excitation stator (3) and the second excitation stator (8) is p, and the number of magnetic poles of the armature stator (14) is q; the first magnetic regulating ring rotor (5) and the second magnetic regulating ring rotor (11) both include magnetic resistance units (23), and the number of magnetic resistance units (23) is p+q; p and q are both integers, and p and q are not equal.

2. The hybrid excitation axial brushless motor according to claim 1, characterized in that: The first excitation stator (3) and the second excitation stator (8) are both annular and have slots, and the first excitation stator (3) and the second excitation stator (8) respectively have a first excitation stator winding (4) and a second excitation stator winding (9) embedded in the slots, and the first excitation stator winding (4) and the second excitation stator winding (9) form a magnetic field with a pole number p when energized.

3. The hybrid excitation axial brushless motor according to claim 1, characterized in that: The first permanent magnet rotor (6) and the second permanent magnet rotor (12) both comprise a permanent magnet rotor disk (21) and a plurality of permanent magnets (13), wherein the permanent magnets (13) are evenly distributed on the circumference of one side of the permanent magnet rotor disk (21), and the permanent magnets (13) are all axially magnetized neodymium iron boron and are spaced apart according to magnetization polarities N and S, and the number of poles of the permanent magnets (13) is q.

4. The hybrid excitation axial brushless motor according to claim 1, characterized in that: The first magnetic tuning ring rotor (5) and the second magnetic tuning ring rotor (11) both further comprise a magnetic tuning ring rotor disk (22); the magnetic resistance unit (23) comprises a plurality of magnetic conductive blocks (24) and a plurality of non-magnetic conductive blocks (25); the magnetic conductive blocks (24) and the non-magnetic conductive blocks (25) are mounted on the magnetic tuning ring rotor disk (22); and the magnetic conductive blocks (24) and the non-magnetic conductive blocks (25) are alternately arranged along the magnetic tuning ring rotor disk (22).

5. The hybrid excitation axial brushless motor according to claim 1, characterized in that: The armature stator (14) comprises a stator core, a magnetic separator (15), a first armature stator winding (19) and a second armature stator winding (20); the stator core has slots on both sides; the first armature stator winding (19) and the second armature stator winding (20) are respectively installed in the slots on both sides of the stator core; the first armature stator winding (19) and the second armature stator winding (20) form a magnetic field with a pole number of p when energized; the magnetic separator (15) is arranged on the stator core between the first armature stator winding (19) and the second armature stator winding (20).

6. The hybrid excitation axial brushless motor according to claim 5, characterized in that: The first armature stator winding (19) and the second armature stator winding (20) located in the stator core slot are both AC windings, and the magnetic fields generated by the first armature stator winding (19) and the second armature stator winding (20) are not coupled, and the magnetic separator (15) is made of non-magnetic material.

7. The hybrid excitation axial brushless motor according to claim 1, characterized in that: The first permanent magnet rotor (6) and the second permanent magnet rotor (12) are rotatably fixed on the rotating shaft (18) via permanent magnet rotor bearings (10) respectively.

8. A method for generating electricity using a hybrid excitation axial brushless motor, characterized in that: The first excitation stator winding (4), the first magnetic ring rotor (5), the first permanent magnet rotor (6) and the first armature stator winding (19) form a first working unit, and the second excitation stator (8), the second magnetic ring rotor (11), the second permanent magnet rotor (12) and the second armature stator winding (20) form a second working unit, and the first working unit and the second working unit work simultaneously and have the same operating principle; Taking the first working unit as an example, the external power component drives the rotating shaft to rotate, and the rotating shaft (8) drives the first magnetic ring rotor (5) rotates, at this time, the number of pole pairs of the AC magnetic field generated by the AC excitation current passing through the first excitation stator winding (4) is p, and the magnetic field is modulated by the first magnetic modulation ring rotor (5), and the p-pole and q-pole magnetic fields are modulated. The modulated q-pole magnetic field interacts with the first armature stator winding (19), and a q-pole AC electromotive force is induced in the first armature stator winding (19); at the same time, the first permanent magnet rotor (6) is forced to rotate in the changing magnetic field, and the rotating first permanent magnet rotor (6) cuts the modulated AC magnetic field, and also induces a q-pole AC electromotive force in the first armature stator winding (19).

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