Inner stator W-type modular magnetic field modulation hybrid excitation motor

Abstract

The invention provides an inner stator W-shaped modular magnetic field modulation hybrid excitation motor, which is used for solving the technical problem that the existing hybrid excitation motor cannot adjust the magnetic field. The motor comprises an outer rotor and a modular stator which are sequentially arranged from outside to inside in the diameter direction, and an air gap is formed between the outer rotor and the modular stator; a winding is arranged in the middle of the modular stator, and armature current and direct-current bias current are introduced into the winding; a plurality of virtual slots are formed in the middle of the outer circumference of the modular stator, a plurality of virtual teeth are generated between the adjacent virtual slots and between the outermost virtual slot and the edge of the modular stator, and permanent magnets are arranged in the virtual slots. According to the invention, the modularized stator and the magnetic field modulation hybrid excitation motor are combined, so that the torque density is improved, and the flexible adjustment of the air-gap magnetic field can be realized at the same time; meanwhile, the stator space contradiction can be relieved, the demagnetization risk of the permanent magnet is reduced, the magnetism adjusting efficiency is improved, and the motor loss is reduced.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet motor design, and relates to the technical field of magnetic field modulation hybrid excitation motor, and particularly to a modular magnetic field modulation hybrid excitation motor. Background Technology

[0002] Hybrid excitation motors combine the advantages of both permanent magnet and electric excitation methods. They utilize high-performance permanent magnets as the primary magnetic field source, and the magnetic field is controlled by adjusting the magnitude and direction of the DC current in the excitation winding. This type of motor retains the high torque density of permanent magnet motors and, through flexible adjustment of the excitation current, adapts to various operating conditions, ensuring efficient and energy-saving operation across a wide range of operating conditions.

[0003] Modular stators have a good suppression effect on low-order harmonics generated by the armature magnetic field. For example, invention patents with application numbers 202110283979.8 and 202311462882.9 disclose a low-harmonic-loss stator modular magnetic field modulation motor and a modulation-enhanced low-harmonic-loss stator modular double-sided excitation motor, respectively. Both invention patents include a modular stator, rotor, windings, permanent magnets embedded in the stator teeth and permanent magnets on the rotor. The armature windings are wound in the stator slots. Both motors can suppress low-order harmonics, reduce losses, and improve motor efficiency. However, neither motor can be magnetically tuned.

[0004] Furthermore, from the perspective of motor control, the presence of armature windings and field windings in the motor does not significantly increase the burden on the inverter. However, from the perspective of motor design, the existence of two sets of windings increases the competition for space within the motor.

[0005] The performance of permanent magnets is greatly affected by temperature. Excessively high temperatures inside the motor can cause irreversible demagnetization of the permanent magnets, leading to safety accidents. Although my country has relatively high reserves of rare earth resources, the raw material for permanent magnets, they are still very scarce compared to reserves of other metals. Therefore, permanent magnets are relatively expensive. Summary of the Invention

[0006] To address the technical problem that existing hybrid excitation motors cannot adjust their magnetic field, this invention proposes an internal stator W-type modular magnetic field modulation hybrid excitation motor. Based on the angle of hybrid excitation, the motor can achieve magnetic field adjustment. It integrates a modular stator, integrated windings, and low permanent magnet usage, making it suitable for fields such as electric vehicles, rail transit, and ship propulsion.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A stator modular magnetic field modulation hybrid excitation motor includes, from the inside out, a modular stator, windings, armature teeth, permanent magnets, virtual teeth, virtual slots, rotor salient poles, and an outer rotor, wherein the modular stator and the outer rotor are separated by an air gap.

[0008] A W-type modular magnetic field modulation hybrid excitation motor with an inner stator includes an outer rotor and a modular stator arranged sequentially from the outside to the inside along the diameter direction, with an air gap between the outer rotor and the modular stator; a winding is provided in the middle of the modular stator, through which armature current and DC bias current are passed; multiple virtual slots are provided in the middle of the outer circumference of the modular stator, and multiple virtual teeth are generated between adjacent virtual slots and between the outermost virtual slot and the edge of the modular stator, with permanent magnets provided in the virtual slots.

[0009] Preferably, the inner wall of the outer rotor is provided with a plurality of rotor salient poles evenly distributed, and the permanent magnets are disposed on both sides of the dummy slot, with the permanent magnets and rotor salient poles being disposed opposite each other.

[0010] Preferably, the modular stator consists of six identical W-shaped sub-modules, which are evenly distributed along the circumference; gaps are provided between adjacent W-shaped sub-modules.

[0011] Preferably, the air gap is achieved by filling it with a non-magnetic material or by directly fixing it to the housing through a mechanical structure.

[0012] Preferably, each W-type submodule includes at least two armature teeth, which include two side armature teeth and a middle armature tooth. The winding is wound on the middle armature tooth. At least two dummy slots are opened on the side of the outer circumference of the middle armature tooth near the air gap. The dummy teeth and the two side armature teeth together provide a magnetic circuit for the permanent magnet excitation source and the DC excitation source.

[0013] Preferably, the structures of the two armature teeth and the middle armature tooth are different, and the shape of the two armature teeth is half the shape of the middle armature tooth.

[0014] Preferably, the spacing between each W-type submodule is uniform and non-uniform, and each W-type submodule has two slots for placing the windings, forming three armature teeth.

[0015] Preferably, the permanent magnet is magnetized radially or parallelly, and the permanent magnets in adjacent W-shaped sub-modules are magnetized in opposite directions, pointing towards the center and away from the center, respectively. The winding adopts a single-layer integrated winding, which is wound on the middle armature tooth of the W-shaped submodule. The integrated winding combines the excitation winding and the armature winding together. The integrated winding contains both alternating current to generate a rotating magnetic field and DC bias current for magnetic field regulation of the motor.

[0016] Preferably, the number of permanent magnet pole pairs in the modular stator is . Ppm The number of stator slots for placing integrated windings is N s The number of salient poles of the rotor is equal to the number of teeth of the outer rotor. N r The corresponding armature winding pole pair number kP a , k For positive integers, the relationship between the three is as follows: in, GCD Number of stator slots N s The greatest common divisor function of the rotor salient pole number.

[0017] Preferably, the modular stator adopts a similar slot pole matching design; The permanent magnet is made of neodymium iron boron magnetic material, and the core of the modular stator and outer rotor is made of stacked high-permeability silicon steel sheets; The winding is divided into two star-connected three-phase modules according to the phase sequence. Three-phase AC current and DC bias current are passed through the winding, and the neutral points of the two three-phase modules are connected together to establish a return path for the zero-sequence current. Due to the presence of the DC bias current, the motor generates an adjustable excitation magnetic field. The current in each coil of the winding is expressed as: in, i A1 , i B1 , i C1 , i A2 , i B2 and i C2 These represent the current flowing through the two three-phase modules, respectively. I ac , I dc , These represent the amplitude of the alternating current, the DC bias current, and the electric angular velocity, respectively. t For a specific moment; Zero-sequence current through Clarke transformation matrix i 0 and DC bias current I dc The following relationship exists between them: in, , These represent the DC current components for magnetization and magnetization weakening, respectively. The DC bias current is adjusted accordingly. I dc Achieving adjustable magnetic field.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The permanent magnet excitation source and the excitation excitation source of the present invention are modulated by the stator and rotor. The magnetic field lines of the two excitation sources are directed along the magnetic flux path generated by the stator and rotor combination. The magnetic conductive material and non-magnetic conductive material in the magnetic flux path work together to guide the permanent magnet magnetic field and the excitation magnetic field to close along a specific path, thereby realizing the modulation of the permanent magnet excitation source and the excitation excitation source by the stator and rotor. Abundant working harmonics are formed in the air gap magnetic field. The main working harmonics in the air gap magnetic field interact with the armature magnetic field harmonics through the magnetic field modulation principle to jointly generate electromagnetic torque. Under the action of the excitation excitation source, the motor magnetic field can be effectively regulated and controlled.

[0019] This invention combines a modular stator with a magnetic field modulation hybrid excitation motor to form an inner stator W-type modular magnetic field modulation hybrid excitation motor. The permanent magnet magnetomotive force and the electrically excited magnetomotive force are combined, which can improve the torque density while realizing flexible adjustment of the air gap magnetic field. At the same time, this structure can alleviate the space contradiction of the stator, reduce the risk of permanent magnet demagnetization, improve the magnetization efficiency, and reduce motor loss.

[0020] This invention is based on the principle of magnetic field modulation. By modulating the number of gear teeth and rotor poles, the initial magnetomotive force of the motor can be modulated into many air gap harmonic magnetic fields with different numbers of pole pairs and different rotational speeds. Furthermore, by utilizing the ratio effect of the magnetic gears that control the rotational speed of the harmonic magnetic field, the motor's utilization of the air gap harmonic magnetic field can be enhanced, thereby achieving a torque increase effect. Torque is generated through electromagnetic energy conversion in the air gap, which improves torque density. Since the DC component in the integrated winding serves as the excitation source, the motor's magnetic field regulation capability is improved. This invention enables the motor to maintain high torque density while simultaneously emphasizing magnetic capability.

[0021] This invention achieves high torque density and strong magnetic adjustment capability while reducing the amount of permanent magnets, which is of great significance. Designing the rotor of the motor on the periphery, it has a larger heat dissipation surface area in direct contact with the external environment, resulting in better heat dissipation. Furthermore, the modular stators can be made of highly thermally conductive non-magnetic materials or directly mechanically fixed with air gaps, allowing for more effective heat dissipation inside the motor. This improved heat dissipation extends the motor's service life.

[0022] The beneficial effects of adopting the above technical solution in this invention are: 1. The present invention employs an integrated winding, in which both alternating current generates a rotating magnetic field to provide torque, and a DC bias current is present for the magnetic field regulation of the motor. A stable magnetic field is generated through DC to optimize and regulate the overall magnetic field distribution.

[0023] 2. The present invention adopts a modular stator and places permanent magnets and windings in the middle armature teeth, which can give the magnetic lines of force generated by the two magnetic sources the same main magnetic flux path, so that the motor has effective magnetic adjustment capability.

[0024] 3. The modular stator of this invention can effectively reduce the stator weight of the motor. At the same time, since the modular stator has a large low-order harmonic reluctance, it has a good suppression effect on the low-order harmonics of the medium and long magnetic circuit generated by the armature magnetic field. Under the premise of ensuring high torque density and magnetic adjustment capability, it effectively reduces the overall weight and loss of the motor.

[0025] 4. The integrated winding of this invention combines the excitation winding and armature winding into one set of windings. By adopting a concentrated winding form, the winding end length can be effectively reduced, torque ripple can be reduced, and copper loss can be reduced, thereby improving the motor operating efficiency; it also simplifies the electromagnetic coupling design and meets the requirements for high power density and high efficiency.

[0026] 5. This invention combines the advantages of permanent magnets and electric excitation, exhibiting excellent field weakening and speed-enhancing capabilities, as well as wide speed adjustment range. The air gap magnetic field can be flexibly controlled by adjusting the electric excitation current, offering advantages such as a wide constant power range, low torque fluctuation, and strong overload capacity. The high torque density and high fault tolerance of this invention make it suitable for various complex operating conditions. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the motor according to an embodiment of the present invention.

[0029] Figure 2 This is a diagram showing the distribution of the armature reaction magnetic field in this invention.

[0030] Figure 3 This is a flux linkage curve of the motor under different excitation states in an embodiment of the present invention.

[0031] Figure 4 This is a magnetic field distribution diagram at a typical location under magnetization of the motor excitation source in an embodiment of the present invention.

[0032] Figure 5 This is a magnetic field line distribution diagram at a typical location under magnetic field weakening of the motor excitation source in an embodiment of the present invention.

[0033] Figure 6 This is a graph showing the no-load back EMF of the motor under different excitation states in an embodiment of the present invention.

[0034] Figure 7 This is a graph showing the output torque of the motor under different excitation states in an embodiment of the present invention.

[0035] In the diagram, the following numbers are used: 1 represents the modular stator; 2 represents the winding; 3 represents the armature tooth; 4 represents the permanent magnet; 5 represents the virtual tooth; 6 represents the virtual slot; 7 represents the rotor salient pole; and 8 represents the outer rotor. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1 like Figure 1As shown, a W-type modular magnetic field modulation hybrid excitation motor with an inner stator includes an outer rotor 8 and a modular stator 1. An air gap exists between the outer rotor 8 and the modular stator 1. Magnetic lines of force from the permanent magnet and excitation magnetic fields on the stator pass through the air gap to the rotor and finally return to the stator, forming a closed magnetic circuit. During this process, the rotor cuts the magnetic lines of force to generate electromagnetic torque and prevents the rotor from rubbing against and colliding with the stator during high-speed rotation. Without the air gap, the outer rotor 8 would directly contact the stator core, causing a short circuit in the magnetic circuit, preventing the conversion of electromagnetic energy into mechanical energy. The circular outer rotor 8 is positioned on the outer side of the modular stator 1. Multiple evenly distributed rotor salient poles 7 are provided on the inner wall of the outer rotor 8. The outer rotor 8 has only a simple salient pole structure, reducing the difficulty of rotor manufacturing and maintenance. This structure also increases the heat dissipation area, which is beneficial for dissipating internal heat and improving heat dissipation. A winding 2 is located in the middle of the modular stator 1. Armature current and DC bias current are passed through the winding 2, which respectively generate the armature magnetic field and the DC excitation magnetic field. Multiple virtual slots 6 are provided in the middle of the outer circumference of the modular stator 1. Multiple virtual teeth 5 are generated between adjacent virtual slots 6 and between the outermost virtual slot 6 and the edge of the modular stator 1. Permanent magnets 4 are placed in the virtual slots 6, which are positioned on both sides of the virtual slots 6. The virtual teeth 5 are used to generate a permanent magnet magnetic field. The permanent magnets 4 provide a magnetic flux path for the magnetic lines of force between the permanent magnet magnetic field and the DC excitation magnetic field, thereby allowing for flexible adjustment of the magnetic field. Both the permanent magnets 4 and the windings 2 are located on the modular stator 1, strengthening the coupling between the permanent magnet magnetic field and the DC excitation magnetic field and enhancing the magnetic field regulation effect of the motor.

[0038] The modular stator 1 consists of six identical W-shaped sub-modules, evenly distributed around the circumference enclosed by the outer rotor 8. The spatial mechanical angles between the W-shaped sub-modules differ by 60°. Too many sub-modules increase the complexity of the internal magnetic circuit, leading to discontinuities and leakage paths. Too few sub-modules result in excessively large distances between permanent magnets, causing highly uneven spatial distribution of the air gap magnetic field. Fewer sub-modules typically mean fewer stator slots, reducing winding utilization and resulting in lower back electromotive force, thus limiting the motor's output capacity. Adjacent W-shaped sub-modules are filled with non-magnetic material or directly fixed to the housing via mechanical structures. Non-magnetic materials (such as thermally conductive epoxy resin) are used to fill the gaps between sub-modules through injection molding / casting processes, while direct mechanical fixing is achieved by independently installing each sub-module using a precision housing structure (slots / threads). Each W-shaped submodule is separated by an air gap, forcing the magnetic flux generated by the permanent magnet 4 and the DC excitation to pass more concentratedly through the air gap at the tip of each tooth into the rotor, rather than short-circuiting in adjacent submodules. This significantly reduces magnetic leakage, enhances the magnetic field modulation effect, improves the utilization rate of the permanent magnet, and increases the air gap magnetic flux density and torque density. Furthermore, the air gap between the submodules improves the motor's heat dissipation. The air gap achieves magnetic field modulation of the permanent magnet magnetic field and the DC excitation magnetic field through strong spatial magnetic permeability changes. After modulation, both interact with the armature magnetic field to efficiently generate electromagnetic torque.

[0039] Each W-shaped submodule contains three (or n indivual, n ≥2) Armature teeth 3, which include two armature teeth on both sides and a middle armature tooth. Winding 2 is wound around the middle armature tooth, enhancing the coupling between the DC excitation magnetic field and the permanent magnet magnetic field in winding 2, and improving the motor's magnetic adjustment capability. Three (or...) are opened on the outer circumference of the middle armature tooth near the air gap. m indivual, m ≥2) Virtual slot 6 generates four virtual teeth 5. The virtual teeth 5, together with the armature teeth on both sides, provide the magnetic circuit for the permanent magnet excitation source and the DC excitation source. The permanent magnet 4 is embedded in the virtual slot 6. The permanent magnet 4 is magnetized radially. The magnetization directions of the permanent magnet 4 in adjacent W-shaped sub-modules are opposite, pointing towards the center and away from the center, respectively, so that the magnetic field lines of the permanent magnet field and the DC excitation field are consistent. At the same time, the permanent magnet 4 can be magnetized in parallel, with the same direction as radial magnetization, and the effect is the same. The armature teeth on both sides and the middle armature tooth have different structures. The armature teeth on both sides are half the shape of the middle armature tooth, which reduces the manufacturing difficulty of the sub-module. Moreover, the armature teeth on both sides do not need to be slotted, further reducing the manufacturing difficulty of the sub-module.

[0040] The spacing between the various W-type submodules can be either uniform or non-uniform. The non-uniform spacing performs better than the uniform spacing because the non-uniform spacing creates an asymmetrical magnetic permeability distribution, which selectively amplifies the main operating harmonics of the motor. Each W-type submodule has two slots for the stator windings 2, thus forming three armature teeth 3. This enhances the coupling between the DC excitation magnetic field and the permanent magnet magnetic field in the windings, improves the motor's magnetic adjustment capability, and reduces the manufacturing difficulty of the submodules.

[0041] The stator winding 2 adopts a single-layer integrated winding, wound on the middle armature tooth of the W-shaped submodule. The integrated winding combines the excitation winding and the armature winding. This integrated winding can be used as an armature winding to generate the armature magnetic field, or as an excitation winding to generate the excitation magnetic field by passing a DC bias current. The integrated winding contains both alternating current to generate a rotating magnetic field and DC bias current for motor magnetic field regulation, generating a stable magnetic field through DC to optimize and regulate the overall magnetic field distribution.

[0042] The number of permanent magnet pole pairs of modular stator 1 is P pm The number of stator slots for placing integrated windings is N s The number of salient poles of the rotor is 7, which is the number of teeth of the outer rotor 8. N r This corresponds to the number of pole pairs of the armature winding. kP a , k For positive integers, the relationship between the three is as follows: in, GCD Number of stator slots N s The greatest common divisor function of the rotor salient pole number.

[0043] The modulation effect of rotor pole number on the permanent magnet magnetic field and DC excitation magnetic field is essentially achieved by using spatial magnetic permeability to modulate the air gap magnetic field, generating a wealth of harmonics. According to the magnetic gear ratio effect, the winding pole number will be matched with the main operating harmonics at low speed and high torque, thus realizing the utilization of the air gap magnetic field.

[0044] The modular stator 1 adopts a similar slot pole matching design, specifically: number of stator slots N s With the number of permanent magnet pole pairs P pm The ratio typically satisfies a near-integer value, ensuring excellent electromagnetic performance and low cogging torque. The modular stator 1's segmented structure creates electromagnetic isolation, reducing electromagnetic interference, leakage flux, and eddy current losses between W-type submodules, thus lowering motor losses and improving operating efficiency. Its main magnetic path is provided by the armature teeth and rotor salient poles 7 of each W-type submodule. Due to the non-uniform air gap between the W-type submodules, the magnetic lines of force on the main magnetic path of each W-type submodule do not interfere with each other, thereby reducing the impact of the modular stator 1 on the motor's operating harmonic magnetic circuit.

[0045] The permanent magnet 4 is made of neodymium iron boron magnetic material, and the core of the modular stator 1 and the outer rotor 8 is made of high permeability silicon steel sheets. The silicon steel sheet stacked core provides a low magnetic reluctance closed path, reduces magnetic leakage, reduces the iron loss of the motor, and improves the heat dissipation performance of the motor.

[0046] Winding 2 is divided into two three-phase modules according to phase sequence. The winding uses two star-connected three-phase modules, each controlled by an independent inverter. Three-phase AC current and DC bias current are supplied to winding 2, and the neutral points of the two three-phase modules are connected together to establish a return path for the zero-sequence current. The presence of the DC bias current generates an adjustable excitation magnetic field in the motor, achieving the effect of magnetization. The current in each coil of winding 2 can be expressed as: in, i A1 , i B1 , i C1 , i A2 , i B2 andi C2 These represent the current flowing through the two three-phase modules, respectively. I ac , I dc , These represent the amplitude of the alternating current, the DC bias current, and the electric angular velocity, respectively. t At time t. Using the Clarke transform matrix, the zero-sequence current... i 0 and DC bias current I dc The following relationship exists between them: in, , These represent the DC current components for magnetization and magnetization weakening, respectively. Zero-sequence current. i 0 and I dc Proportional, by adjusting the DC bias current I dc Achieving adjustable magnetic field.

[0047] The modular stator 1 has a large harmonic reluctance to the low-order harmonics generated by the armature magnetic field, and has a good suppression effect on the low-order harmonics of the long magnetic circuit generated by the concentrated winding structure of the motor, effectively reducing motor losses.

[0048] Example 2 like Figure 1As shown, an internal stator W-type modular magnetic field modulation hybrid excitation motor is disclosed. The modular stator 1 consists of six identical W-type sub-modules. Each W-type sub-module has two slots for accommodating integrated windings 2, thus forming three armature teeth 3. The armature teeth 3 include two side armature teeth and a middle armature tooth. The two side armature teeth have the same structure and are not slotted. The side armature teeth and the middle armature tooth have different structures, each being half the shape of the middle armature tooth. This design can reduce the manufacturing difficulty of the sub-modules without affecting the motor performance. By opening three virtual slots 6 on the side of the middle armature tooth near the air gap, four virtual teeth 5 are generated, and permanent magnets 4 are embedded in the virtual slots 5. The magnetization direction adopts radial excitation with directions away from the center and towards the center. The virtual teeth 5, together with the two side armature teeth, provide magnetic circuits for the permanent magnet excitation source and the DC excitation source, and enhance the magnetic field modulation effect of the motor. The integrated winding 2 adopts a single-layer concentrated winding. The six coils are divided into two three-phase modules according to the phase sequence. The winding adopts two star-connected three-phase modules. Three-phase AC current and DC current are simultaneously passed through the winding 2, and the neutral points of the two three-phase modules are connected together to establish a return path for the zero-sequence current. Due to the presence of the DC excitation source, the excitation magnetic field of the motor is adjustable, achieving the effect of magnetic modulation. The outer rotor 8 is only a simple rotor salient pole structure. In order to achieve a symmetrical distribution of the three phases of the winding, the number of rotor salient poles can be any integer other than a multiple of the number of phases, so as to meet the magnetic field modulation effect and generate effective working harmonics that interact with the armature magnetic field harmonics, ensuring the motor's torque output and magnetic modulation capability.

[0049] In the radial direction, a 0.5mm air gap exists between the modular stator 1 and the outer rotor 8. Both the outer rotor 8 and the modular stator 1 are made of stacked high-permeability DW540 silicon steel sheets. The permanent magnet 4 is placed in the dummy slot 6 of the modular stator 1, using a radial magnetization method, and the magnetization directions of the permanent magnets between adjacent W-shaped sub-modules are opposite. The permanent magnet area of ​​this invention is 230mm². 2 Given this permanent magnet area, the motor's output torque indicates that the motor has a high utilization rate of the permanent magnet.

[0050] In this embodiment, an integrated winding is used, which combines alternating current to generate a rotating magnetic field and provide torque, with a DC bias current for regulating the motor's magnetic field. This DC bias current generates a stable magnetic field, optimizing and adjusting the overall magnetic field distribution. The integrated windings all employ a concentrated winding configuration, effectively reducing winding end length, lowering copper losses, and thus improving motor operating efficiency.

[0051] The results were obtained through finite element analysis. Figures 2-7 . Figure 2 This is a magnetic field diagram of the motor under no-load and magnetized states according to an embodiment of the present invention. Figure 2It can be seen that under the magnetization condition, the magnetic lines of the permanent magnet field and the DC excitation field are normally superimposed, and there is no magnetic leakage. Furthermore, the main magnetic circuit of the magnetic lines of force is closed only on their respective sub-modules, which further reduces magnetic leakage and increases the torque of the motor. Figure 3 The flux linkage curves of the motor under different excitation states in embodiments of the present invention are obtained by... Figure 3 It can be seen that when the motor is under conditions of increasing and decreasing magnetism, the increase and decrease of magnetic flux can be effectively controlled. Figure 4 This is the magnetic field line distribution at a typical location under magnetization of the motor excitation source in an embodiment of the present invention. Figure 4 It can be seen that under the magnetization condition, the magnetic flux paths of the permanent magnet magnetic field lines and the DC excitation magnetic field lines are exactly the same, and the two magnetic field lines are superimposed, thus achieving the magnetization effect. Figure 5 This is the magnetic field line distribution at a typical location under field weakening of the motor excitation source in an embodiment of the present invention. Figure 5 It can be seen that under the condition of magnetic field weakening, the magnetic flux lines of the permanent magnet field and the magnetic flux lines of the DC excitation field have the same magnetic flux path, but opposite direction, thus achieving the effect of magnetic field weakening. Figure 6 To illustrate the no-load back EMF of the motor under different excitation states in embodiments of the present invention, through... Figure 6 It can be seen that the amplitude of the motor's no-load back EMF increases and decreases under strong and weak magnetic conditions, respectively, indicating the effectiveness of the motor's magnetic adjustment. Figure 7 To determine the output torque of the motor under different excitation states in embodiments of the present invention, through... Figure 7 It can be observed that under magnetizing conditions, the motor's output torque increases significantly. Under weakening conditions, the motor's output torque decreases significantly. For example... Figures 2-7 As shown, the motor of the present invention can adjust the magnetic flux, no-load back EMF and output torque of the motor by adjusting the DC excitation source, so that it has good dynamic performance.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A W-type modular magnetic field modulation hybrid excitation motor with an inner stator, characterized in that, It includes an outer rotor (8) and a modular stator (1) arranged sequentially from the outside to the inside along the diameter direction. An air gap is provided between the outer rotor (8) and the modular stator (1). A winding (2) is provided in the middle of the modular stator (1). An armature current and a DC bias current are passed through the winding (2). A plurality of virtual slots (6) are provided in the middle of the outer circumference of the modular stator (1). A plurality of virtual teeth (5) are generated between adjacent virtual slots (6) and between the outermost virtual slot (6) and the edge of the modular stator (1). A permanent magnet (4) is provided in the virtual slot (6).

2. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 1, characterized in that, The inner wall of the outer rotor (8) is provided with a plurality of rotor salient poles (7) evenly distributed. The permanent magnet (4) is arranged on both sides of the virtual slot (6), and the permanent magnet (4) is arranged opposite to the rotor salient poles (7).

3. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 1 or 2, characterized in that, The modular stator (1) consists of six identical W-shaped sub-modules, which are evenly distributed along the circumference; gaps are provided between adjacent W-shaped sub-modules.

4. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 3, characterized in that, The air gap is achieved by filling it with non-magnetic material or by directly fixing it to the casing through a mechanical structure.

5. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 3, characterized in that, Each W-type submodule contains at least two armature teeth (3). The armature teeth (3) include two side armature teeth and a middle armature tooth. The winding (2) is wound on the middle armature tooth. At least two virtual slots (6) are opened on the side of the outer circumference of the middle armature tooth near the air gap. The virtual teeth (5) together with the side armature teeth provide a magnetic circuit for the permanent magnet excitation source and the DC excitation source.

6. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 5, characterized in that, The armature teeth on both sides and the middle armature tooth have different structures, and the shape of the armature teeth on both sides is half the shape of the middle armature tooth.

7. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 5 or 6, characterized in that, The spacing between each W-type submodule is uniform and non-uniform. Each W-type submodule has two slots for placing the winding (2), forming three armature teeth (3).

8. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 5 or 6, characterized in that, The permanent magnet (4) is magnetized radially or parallelly. The magnetization directions of the permanent magnets (4) in adjacent W-shaped sub-modules are opposite, pointing towards the center and away from the center, respectively. The winding (2) adopts a single-layer integrated winding. The integrated winding is wound on the middle armature tooth of the W-type sub-module. The integrated winding brings together the excitation winding and the armature winding. The integrated winding contains both AC current to generate a rotating magnetic field and DC bias current for the magnetic field regulation of the motor.

9. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 8, characterized in that, The number of permanent magnet pole pairs of the modular stator (1) is P pm The number of stator slots for placing integrated windings is N s The number of salient poles of the rotor is equal to the number of teeth of the outer rotor (8). N r The corresponding armature winding pole pair number kP a , k For positive integers, the relationship between the three is as follows: in, GCD Number of stator slots N s The greatest common divisor function of the rotor salient pole number.

10. The W-type modular magnetic field modulation hybrid excitation motor with inner stator according to claim 9, characterized in that, The modular stator (1) adopts a similar slot pole matching design; The permanent magnet (4) is made of neodymium iron boron magnetic material, and the core of the modular stator (1) and the outer rotor (8) is made of stacked high permeability silicon steel sheets; The winding (2) is divided into two star-connected three-phase modules according to the phase sequence. Three-phase AC current and DC bias current are passed into the winding (2), and the neutral points of the two three-phase modules are connected together to establish the return path of the zero-sequence current. Due to the presence of the DC bias current, the motor generates an adjustable excitation magnetic field. The current in each coil of the winding (2) is expressed as follows: in, i A1 , i B1 , i C1 , i A2 , i B2 and i C2 These represent the current flowing through the two three-phase modules, respectively. I ac , I dc , These represent the amplitude of the alternating current, the DC bias current, and the electric angular velocity, respectively. t For a specific moment; Zero-sequence current through Clarke transformation matrix i 0 and DC bias current I dc The following relationship exists between them: in, , These represent the DC current components for magnetization and magnetization weakening, respectively. The DC bias current is adjusted accordingly. I dc Achieving adjustable magnetic field.

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