Five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor

Abstract

The invention discloses a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor, and relates to the technical field of permanent magnet motors. The motor comprises an outer stator, an outer stator armature winding, an intermediate rotor, an intermediate rotor permanent magnet, an inner stator, an inner stator armature winding and a rotating shaft. Through flexible control of the inner stator winding and the outer stator winding, multiple operation modes of the motor are realized, and the requirements of different driving working conditions of the electric vehicle are met. By fully utilizing multiple pairs of inner and outer air gap flux density harmonics, the torque output capability and the power factor of the motor are improved. In addition, the motor also has certain safety redundancy, when the inner stator windings or the outer stator windings go wrong, only all loops of the inner stator windings or the outer stator windings need to be disconnected, only the normal winding loop is powered, and the motor can operate normally. Compared with a common three-phase motor, the motor can realize higher power output and has a fault tolerance function.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet motors, and particularly to a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor. Background Art

[0002] New energy electric vehicles are being increasingly widely used in the global transportation field due to their significant advantages of low carbon and environmental protection. However, problems such as insufficient charging infrastructure and limited endurance of current electric vehicles still remain the main bottlenecks restricting the rapid development of this industry. Especially against the background that it is difficult to make breakthrough progress in battery technology in the short term, the optimization of drive motor control performance is particularly important. It has become the key to improving the overall performance of the electric vehicle drive system and directly determines the power performance and energy efficiency level of new energy vehicles.

[0003] During the actual road driving process, electric vehicles face complex and variable working condition requirements, including but not limited to various operating states such as smooth starting, emergency braking, heavy-load climbing, high-speed cruising, and frequent acceleration and deceleration. This diversity poses a severe challenge to the design of drive motors. Therefore, the design of modern electric vehicle drive motors not only needs to continuously improve the two core indicators of torque density and power density, but also must fully consider the special requirements under different driving conditions to achieve the optimization of dynamic performance. At the same time, to ensure driving safety, the design of drive motors also needs to have high safety redundancy performance and fault tolerance ability to ensure that basic operating functions can still be maintained under extreme working conditions or sudden failures. Summary of the Invention

[0004] The purpose of the present invention is to provide a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor, which can not only achieve high torque density and power density, but also adapt to different driving conditions, and at the same time has high safety redundancy performance and fault tolerance performance.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: A five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor, adopting an inner and outer double-stator and an intermediate single-rotor structure, includes an outer stator, an outer stator armature winding, an intermediate rotor, an intermediate rotor permanent magnet, an inner stator, an inner stator armature winding, and a rotating shaft, wherein: The intermediate rotor permanent magnet serves as the excitation unit of the motor, with 22 pairs of poles, and its structure adopts a V-V structure; The tooth grooves of the outer stator and the tooth grooves of the inner stator serve as the magnetic field modulation units of the motor, and the number of both is 20; The outer stator armature winding and the inner stator armature winding serve as the armature units of the motor, are respectively distributed in the tooth grooves of the outer stator and the inner stator, and are designed according to the 5-phase 2-pole magnetic field distribution; The number of pole pairs of the armature unit is equal to the difference between the number of pole pairs of the excitation unit and the number of pole pairs of the magnetic field modulation unit.

[0006] Further, the initial permanent magnet magnetomotive force of the intermediate rotor permanent magnet is subjected to Fourier decomposition, and the expression for the permanent magnet magnetomotive force of the intermediate rotor permanent magnet is obtained as: ; where is the amplitude of the component of the j-th pair of poles in the permanent magnet magnetomotive force, is the number of pole pairs of the intermediate rotor permanent magnet, is the position angle of the intermediate rotor, is the angular velocity of the intermediate rotor, t is the time.

[0007] Further, under the modulation action of the permanent magnet magnetomotive force, the expressions for the Fourier decomposition of the permeance of the outer stator teeth and the inner stator teeth are: ; where is the permeance function of the outer stator teeth, is the constant component in the permeance of the outer stator teeth, is the amplitude of the component of the k-th pair of poles in the permeance of the outer stator teeth, is the number of teeth of the outer stator, is the permeance function of the inner stator teeth, is the constant component in the permeance of the inner stator teeth, is the amplitude of the component of the l-th pair of poles in the permeance of the inner stator teeth, is the number of teeth of the inner stator, is the angle between the center lines of the inner and outer stator teeth.

[0008] Further, the air-gap magnetic flux density in the air gaps between the outer stator and the inner stator is obtained by multiplying the initial permanent magnet magnetomotive force of the intermediate rotor permanent magnet by the permeance of the inner stator and the outer stator teeth, and the expression is: , where is the air-gap magnetic flux density of the outer stator, is the air-gap magnetic flux density of the inner stator. Through the modulation action of the inner and outer stator teeth on the initial permanent magnet magnetomotive force, the main air-gap magnetic flux density in the inner and outer stator air-gap magnetic flux densities is pairs of poles, the harmonic of the outer stator air-gap magnetic flux density is pairs of poles, and the harmonic of the inner stator air-gap magnetic flux density is pairs of poles.

[0009] Further, the functional expressions of the outer stator armature winding and the inner stator armature winding are: ; where is the function of the outer stator armature winding, is the function of the inner stator armature winding, is the number of turns of the outer stator armature winding, is the number of turns of the inner stator armature winding, n is the harmonic order in the winding function.

[0010] Furthermore, the expressions for the no-load magnetic fluxes of the outer stator armature winding and the inner stator armature winding are: ; where is the magnetic flux of the outer stator armature winding, is the winding factor of the outer stator armature winding, is the inner diameter of the outer stator, is the length of the motor shaft; is the magnetic flux of the inner stator armature winding, is the winding factor of the inner stator armature winding, is the outer diameter of the inner stator, l is a multiple of the number of slots of the inner stator.

[0011] Furthermore, the no-load back electromotive forces induced in the outer stator armature winding and the inner stator armature winding are obtained by differentiating the no-load magnetic fluxes, and their expressions are: ; where e 0 ( t ) is the no-load back electromotive force induced in the outer stator armature winding, e i ( t ) is the no-load back electromotive force induced in the inner stator armature winding, k w is the winding factor of the winding.

[0012] Furthermore, the expressions for the amplitudes of the no-load back electromotive forces generated by the outer stator armature winding and the inner stator armature winding are: ; where is the amplitude of the no-load back electromotive force generated by the outer stator armature winding, is the amplitude of the no-load back electromotive force generated by the inner stator armature winding, F 1 is the fundamental magnetomotive force.

[0013] Furthermore, the expression for the average torque of the electromagnetic torque generated by the outer stator armature winding and the inner stator armature winding is: ; where is the average torque of the electromagnetic torque generated by the outer stator armature winding, is the amplitude of the phase current flowing through the outer stator armature winding, is the average torque of the electromagnetic torque generated by the inner stator armature winding, is the amplitude of the phase current flowing through the inner stator armature winding, P oe is the electromagnetic power generated by the outer stator armature winding, P ie is the electromagnetic power generated by the inner stator armature winding.

[0014] Furthermore, the outer stator and the inner stator are respectively provided with electrical ports.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by the present invention can realize multiple operating modes of the motor through flexible control of its inner and outer stator windings, meeting the requirements of different driving conditions of electric vehicles; The five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by the present invention improves the torque output ability and power factor of the motor by making full use of multiple pairs of air-gap magnetic density harmonics inside and outside; The five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by the present invention has a certain safety redundancy. When a problem occurs in the inner stator winding or the outer stator winding, only the circuits of all the inner stator windings or the outer stator windings need to be disconnected, and only the normal winding circuits are powered, and the motor can operate normally; The five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by the present invention has a fault tolerance function. When one phase, two phases or three phases of the inner stator winding or the outer stator winding fail, the inner stator or the outer stator of the motor can still continue to work through the fault tolerance control strategy; The five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by the present invention can generate a greater power and torque output compared with a common three-phase permanent magnet motor when the magnetic field is the same and the armature current magnitude is equal.

[0016] In summary, the present invention proposes a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor, which realizes the coordinated excitation and multi-mode operation of the motor by using two electrical ports inside and outside the dual stator. It can not only achieve a higher torque density and power density, but also realize different driving conditions. At the same time, it has a high safety redundancy performance and a fault tolerance performance, providing a technical guarantee for the drive application of new energy electric vehicles and having a high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for use in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other accompanying drawings can also be obtained based on these drawings.

[0018] Figure 1 Schematic diagram of the structure of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0019] Figure 2 Speed, current, back electromotive force, and torque waveform diagrams of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention operating at high speed and small torque.

[0020] Figure 3 Speed, current, back electromotive force, and torque waveform diagrams of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention operating at low speed and large torque.

[0021] Figure 4 Inner stator air-gap magnetic density waveform diagram of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0022] Figure 5 Outer stator air-gap magnetic density waveform diagram of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0023] Figure 6 Harmonic distribution diagram of the inner stator air-gap magnetic density of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0024] Figure 7 Harmonic distribution diagram of the outer stator air-gap magnetic density of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0025] Figure 8 Speed, current, back electromotive force, and torque waveform diagrams of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor with the inner stator winding powered and the outer stator winding disconnected provided by an embodiment of the present invention.

[0026] Figure 9 Speed, current, back electromotive force, and torque waveform diagrams of a five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor with the inner stator winding disconnected and the outer stator winding powered provided by an embodiment of the present invention.

[0027] Figure 10The speed, current, back electromotive force, and torque waveform diagrams when the C-phase winding of the outer stator of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by the invention embodiment is disconnected and the other phases are powered normally.

[0028] Figure 11 The speed, current, back electromotive force, and torque waveform diagrams when the A-phase and B-phase windings of the inner stator of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by the invention embodiment are disconnected and the other phases are powered normally.

[0029] Figure 12 The power and torque outputs of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by the invention embodiment and a common three-phase permanent magnet motor when the magnetic fields are the same and the armature currents are equal in magnitude. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present application.

[0031] The core of the present application is to propose a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor, which can not only achieve high torque density and power density, but also can achieve different driving conditions, and at the same time has high safety redundancy performance and fault tolerance performance.

[0032] In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0033] Figure 1 The structural schematic diagram of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by the invention embodiment is as Figure 1 shown. The five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor includes: an outer stator 1, an outer stator armature winding 2, an intermediate rotor 3, an intermediate rotor permanent magnet 4, an inner stator 5, an inner stator armature winding 6, and a rotating shaft 7.

[0034] The motor adopts an inner and outer double-stator and single-rotor structure in the middle. The number of teeth and slots of the outer stator 1 and the inner stator 5 are both 20, and the number of pole pairs of the intermediate rotor permanent magnet 4 is 22 pairs of poles.

[0035] Armature windings are distributed in the slots of the outer stator and the inner stator of the motor. The armature windings are designed according to the 5-phase 4-pole magnetic field distribution, as Figure 1As shown, the A-phase of the outer stator winding is designed with a layout structure of A1+ and A1-, A2+ and A2-, A3+ and A3-, A4+ and A4- to generate a 4-pole magnetic field. The other phases of the outer stator armature winding and the inner stator armature winding are designed with a layout structure as shown in Figure 1 to generate a 4-pole magnetic field.

[0036] The structure of the intermediate rotor permanent magnet 4 of the motor adopts a V-V structure with good magnetic flux concentrating effect, as shown in Figure 1 Four adjacent rotor permanent magnets are arranged in an approximate V-V structure. The design of the V-structure permanent magnet makes the magnetic lines of force concentrate in the V-shaped structure, thereby enhancing the magnetic flux density in the working air gap. Specifically, through the change of the geometric shape and the proper arrangement of the permanent magnet and the magnetic conductor in the V-shaped structure, more magnetic lines of force are gathered into the working air gap, reducing the magnetic leakage phenomenon, and thus improving the utilization rate of the magnetic field.

[0037] The armature unit of the motor is the inner stator armature winding 6 and the outer stator armature winding 2, and the number of pole pairs of the armature unit is 2.

[0038] The excitation unit of the motor is the intermediate rotor permanent magnet 4, and the number of pole pairs of the excitation unit is 22. The number of pole pairs in the excitation unit cannot be too large or too small. The larger the number of pole pairs, the more permanent magnet materials are required, and the higher the design cost. The smaller the number of pole pairs, the less permanent magnet materials are required, and the relative magnetic field strength inside the motor is smaller, and the output torque is smaller.

[0039] The initial permanent magnet magnetomotive force of the intermediate rotor permanent magnet is subjected to Fourier decomposition, and the expression of the permanent magnet magnetomotive force of the intermediate rotor permanent magnet is obtained as: ; where is the amplitude of the component of the j-th pair of poles in the permanent magnet magnetomotive force, is the number of pole pairs of the intermediate rotor permanent magnet, is the position angle of the intermediate rotor, is the angular velocity of the intermediate rotor, t is the time.

[0040] The magnetic field modulation unit of the motor is the inner stator teeth and the outer stator teeth. Under the modulation of the permanent magnet magnetomotive force, the expressions of the Fourier decomposition of the permeance of the outer stator teeth and the inner stator teeth are: ; where is the permeance function of the outer stator teeth, is the constant component in the permeance of the outer stator teeth, is the amplitude of the component of the k-th pair of poles in the permeance of the outer stator teeth, is the number of outer stator teeth, is the permeance function of the inner stator teeth, is the constant component in the magnetic permeance of the inner stator teeth, is the amplitude of the l - th pair of poles component in the magnetic permeance of the inner stator teeth, is the number of inner stator teeth, is the angle between the center lines of the inner and outer stator teeth.

[0041] Furthermore, multiplying the initial permanent - magnet magnetomotive force of the intermediate rotor permanent magnet by the magnetic permeance of the inner stator and outer stator teeth can obtain the air - gap magnetic density in the air - gaps of the outer stator and inner stator. The expression is: ; where is the air - gap magnetic density of the outer stator, is the air - gap magnetic density of the inner stator. Through the modulation of the initial permanent - magnet magnetomotive force by the inner and outer stator teeth, the main air - gap magnetic density in the inner and outer stator air - gap magnetic densities is pairs of poles, the harmonic of the outer stator air - gap magnetic density is pairs of poles, and the harmonic of the inner stator air - gap magnetic density is pairs of poles.

[0042] When the number of permanent - magnet pole pairs is 22 and the number of inner and outer stator slots is 20, the main air - gap magnetic density in the air - gap magnetic density is 22 pairs of poles, and the main harmonics of the air - gap magnetic density are 2 and 42 pairs of poles.

[0043] The armature unit of the motor is the inner - stator armature winding and the outer - stator armature winding. Through reasonable winding design, effective air - gap magnetic density can be extracted, generating good electromagnetic performance of the motor. The functional expressions of the outer - stator armature winding and the inner - stator armature winding of the five - phase fault - tolerant double - stator magnetic - field - modulation permanent - magnet synchronous motor of the present invention are: ; where is the outer - stator armature - winding function, is the inner - stator armature - winding function, is the number of turns of the outer - stator armature winding, is the number of turns of the inner - stator armature winding, n is the harmonic order in the winding function.

[0044] Furthermore, the expressions for the no - load magnetic flux linkages of the outer - stator armature winding and the inner - stator armature winding are: ; where is the magnetic flux linkage of the outer - stator armature winding, is the winding factor of the outer - stator armature winding, is the inner diameter of the outer stator, is the length of the motor shaft; is the magnetic flux linkage of the inner - stator armature winding, is the winding factor of the inner stator armature winding, is the outer diameter of the inner stator, l is a multiple of the number of slots in the inner stator.

[0045] The no-load back electromotive force induced by the outer stator armature winding and the inner stator armature winding is obtained by differentiating the no-load magnetic flux, and its expression is: ; where e 0 ( t ) is the no-load back electromotive force induced by the outer stator armature winding, e i ( t ) is the no-load back electromotive force induced by the inner stator armature winding, k w is the winding factor of the winding.

[0046] It can be seen from this that the periods of the no-load magnetic flux and the no-load back electromotive force of the motor are only related to jP m ω r When the angular velocity of the motor rotor ω r is a constant, and the magnetic field modulation motor mainly uses the fundamental wave of the permanent magnet magnetomotive force with j = 1 for modulation, then jP m ω r is a fixed value, and the same initial permanent magnet harmonic generates the same time period of the air-gap magnetic density harmonic with the pole pair number of P m , P m -N ost , P m +N ost This means that although there are a large number of and rich air-gap magnetic density harmonics in the air gap of the motor, the same modulated spatial air-gap magnetic density harmonics can generate the no-load magnetic flux and the no-load back electromotive force harmonics with the same frequency, thereby improving the utilization rate of the motor harmonics.

[0047] When the harmonic of the permanent magnet magnetomotive force with j = 1 generates the main no-load back electromotive force, the amplitude expressions of the no-load back electromotive force generated by the outer stator armature winding and the inner stator armature winding are: ; where is the amplitude of the no-load back electromotive force generated by the outer stator armature winding, is the amplitude of the no-load back electromotive force generated by the inner stator armature winding, F1 is the fundamental magnetomotive force.

[0048] When sinusoidal currents are applied to the inner and outer stator windings, electromagnetic torques are generated in both the inner and outer stator armature windings. The total torque of the five-phase fault-tolerant dual-stator field-modulated permanent magnet synchronous motor of the present invention is equal to the sum of the electromagnetic torques generated by the inner stator armature winding and the outer stator armature winding. The expressions for the average torques of the electromagnetic torques generated by the outer stator armature winding and the inner stator armature winding are as follows: ; where is the average torque of the electromagnetic torque generated by the outer stator armature winding, is the amplitude of the phase current flowing through the outer stator armature winding, is the average torque of the electromagnetic torque generated by the inner stator armature winding, is the amplitude of the phase current flowing through the inner stator armature winding, P oe is the electromagnetic power generated by the outer stator armature winding, P ie is the electromagnetic power generated by the inner stator armature winding.

[0049] It can be seen from the above formula that the five-phase fault-tolerant dual-stator field-modulated permanent magnet synchronous motor of the present invention makes full use of the inner and outer multiple pairs of air-gap magnetic density harmonics, improving the torque output ability of the motor.

[0050] The pole-slot combination of the motor conforms to the field modulation principle, and the satisfied relationship is that the number of pole pairs of the armature unit is equal to the difference between the number of pole pairs of the excitation unit and the number of pole pairs of the field modulation unit. In addition, integrating the winding distribution theory in the design of permanent magnet motors, the number of pole pairs of the armature unit, the number of pole pairs of the excitation unit, and the number of pole pairs of the field modulation unit of the three-phase field-modulated permanent magnet motor can be selected as 2, 14, 12; 3, 21, 18; 4, 28, 24. The number of pole pairs of the armature unit, the number of pole pairs of the excitation unit, and the number of pole pairs of the field modulation unit of the five-phase field-modulated permanent magnet motor are selected as 2, 22, 20. The number of pole pairs of the armature unit, the number of pole pairs of the excitation unit, and the number of pole pairs of the field modulation unit of the six-phase field-modulated permanent magnet motor are selected as 2, 26, 24. After repeated experiments, the present invention preferably selects a five-phase field-modulated permanent magnet motor, and the number of pole pairs of the armature unit, the number of pole pairs of the excitation unit, and the number of pole pairs of the field modulation unit are 2, 22, 20.

[0051] In specific implementation, for the five-phase fault-tolerant dual-stator field-modulated permanent magnet synchronous motor, by flexibly controlling its inner and outer stator armature windings, multiple operating modes of the motor can be realized to meet the requirements of different driving conditions of electric vehicles. The motor of the present invention utilizes the two electrical ports of the dual stator, the inner and the outer, to achieve cooperative excitation and multi-mode operation of the motor.

[0052] As Figure 2 shown, when the armature windings of the inner stator and the outer stator simultaneously carry an armature current of 5 A, the motor speed is controlled at 1500 revolutions per minute, and the average torque output of the motor is 64 N·m. This operating condition corresponds to the situation where the vehicle is running at a constant speed on a straight road at high speed with low torque. The current, back electromotive force, speed, and torque waveform diagrams of the motor of the present invention are as Figure 2 shown.

[0053] As Figure 3 shown, when the armature windings of the inner stator and the outer stator simultaneously carry an armature current of 15 A, the motor speed is controlled at 500 revolutions per minute, and the average torque output of the motor is 154 N·m. This operating condition corresponds to the situation where the vehicle is running at low speed with high torque when going uphill. The current, back electromotive force, speed, and torque waveform diagrams of the motor of the present invention are as Figure 3 shown.

[0054] In a specific implementation, for the five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor, by making full use of multiple pairs of air-gap magnetic density harmonics of the inner and outer stators, the torque output capacity and power factor of the motor are improved.

[0055] As Figure 4 shown, when the armature windings of the inner stator and the outer stator simultaneously carry an armature current of 5 A, the motor speed is controlled at 1500 revolutions per minute, and the magnitude of the air-gap magnetic density of the inner stator is less than 2 T, indicating that there is no saturation in the air-gap of the inner stator, verifying that the inner stator part of the designed motor is not prone to magnetic saturation and meeting the magnetic saturation design index of the motor.

[0056] As Figure 5 shown, when the armature windings of the inner stator and the outer stator simultaneously carry an armature current of 5 A, the motor speed is controlled at 1500 revolutions per minute, and the magnitude of the air-gap magnetic density of the outer stator is less than 2 T, indicating that there is no saturation in the air-gap of the outer stator, verifying that the outer stator part of the designed motor is not prone to magnetic saturation and meeting the magnetic saturation design index of the motor.

[0057] As Figure 6 shown, when the number of pole pairs of the middle rotor permanent magnet is 22 and the number of teeth and slots of the inner stator is 20, the main air-gap magnetic density in the air-gap magnetic density of the inner stator is 22 pole pairs, and the other air-gap magnetic density harmonics are mainly 2 and 42 pole pairs, verifying that this field modulation motor can make full use of multiple pairs of air-gap magnetic density harmonics of the inner stator, thereby improving the torque output capacity of the motor.

[0058] As Figure 7As shown, when the number of pole pairs of the intermediate rotor permanent magnet is 22 pairs of poles and the number of stator slots of the outer stator is 20, the main air-gap magnetic density in the outer stator air-gap magnetic density is 22 pairs of poles, and the other air-gap magnetic density harmonics are mainly 2 and 42 pairs of poles, verifying that the magnetic field modulation motor can make full use of the multi-pair air-gap magnetic density harmonics of the outer stator, thereby improving the torque output ability of the motor.

[0059] In a specific implementation, the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor has a certain safety redundancy. When there is a problem with the inner stator armature winding or the outer stator armature winding, it only needs to disconnect the circuits of all the inner stator armature windings or the outer stator armature windings, and only supply power to the normal winding circuits, and the motor can operate normally.

[0060] As Figure 8 shown, when the inner stator armature winding passes through a current of 5 A and the outer stator armature winding circuit is disconnected, the motor operates at 1500 revolutions per minute, and the average torque output of the motor is 33 N·m. This working condition corresponds to the high-speed and low-torque working condition of the vehicle when the double-stator magnetic field modulation permanent magnet synchronous motor only has the inner stator working.

[0061] As Figure 9 shown, when the inner stator armature winding circuit is disconnected and the outer stator armature winding passes through a current of 5 A, the motor operates at 1500 revolutions per minute, and the average torque output of the motor is 35 N·m. This working condition corresponds to the high-speed and low-torque working condition of the vehicle when the double-stator magnetic field modulation permanent magnet synchronous motor only has the outer stator working.

[0062] In a specific implementation, the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor has a fault tolerance function. When one phase, two phases or three phases of the inner stator winding or the outer stator winding have faults, through the fault tolerance control strategy, the inner stator or the outer stator of the motor can still continue to work.

[0063] As Figure 10 shown, when the outer stator C-phase winding is disconnected and the other phase windings all pass through a current of 5 A, all phases of the inner stator armature winding pass through a current of 5 A, the motor operates at 1500 revolutions per minute, and the average torque output of the motor is 58 N·m. This working condition corresponds to the high-speed and low-torque working condition of the vehicle when the double-stator magnetic field modulation permanent magnet synchronous motor has an outer stator single-phase winding fault and the outer stator and the inner stator work simultaneously.

[0064] As Figure 11 shown, when the inner stator A-phase and B-phase windings are disconnected and the other phase windings all pass through a current of 5 A, all phases of the outer stator armature winding pass through a current of 5 A, the motor operates at 1500 revolutions per minute, and the average torque output of the motor is 52 N·m. This working condition corresponds to the high-speed and low-torque working condition of the vehicle when the double-stator magnetic field modulation permanent magnet synchronous motor has an inner stator two-phase winding fault and the outer stator and the inner stator work simultaneously.

[0065] In a specific implementation, for the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor, when the magnetic field is the same and the armature current magnitude is equal, the motor can generate a greater power and torque output compared to a conventional three-phase permanent magnet motor.

[0066] As Figure 12 shown, when the armature currents of both the inner stator armature winding and the outer stator armature winding of the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor flow through 5 A, the motor speed is controlled at 1500 revolutions per minute, the average torque output of the motor is 64 N·m, and the power output of the motor is 10 kW; while the average torque output of a conventional three-phase permanent magnet motor is 48 N·m, and the power output of the motor is 7.5 kW. (a) is the average torque waveform output by the conventional three-phase permanent magnet motor, (b) is the power waveform output by the conventional three-phase permanent magnet motor, (c) is the average torque waveform output by the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor, and (d) is the power waveform output by the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor.

[0067] The above has introduced in detail the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by this application. The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor, characterized in that: The invention adopts an inner and outer double stator and an intermediate single rotor structure, comprising an outer stator (1), an outer stator armature winding (2), an intermediate rotor (3), an intermediate rotor permanent magnet (4), an inner stator (5), an inner stator armature winding (6) and a rotating shaft (7), wherein: The intermediate rotor permanent magnet (4) serves as an excitation unit of the motor, has 22 pairs of poles, and adopts a VV structure; The tooth slots of the outer stator (1) and the tooth slots of the inner stator (5) serve as magnetic field modulation units of the motor, and the number of the tooth slots is 20; The outer stator armature winding (2) and the inner stator armature winding (6) serve as the armature units of the motor, are respectively distributed in the tooth slots of the outer stator (1) and the inner stator (5), and are designed according to a five-phase two-pole magnetic field distribution; The number of pole pairs of the armature unit is equal to the difference between the number of pole pairs of the excitation unit and the number of pole pairs of the magnetic field modulation unit.

2. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 1, characterized in that: The initial permanent magnet magnetomotive force of the intermediate rotor permanent magnet (4) is subjected to Fourier decomposition, and the expression of the permanent magnet magnetomotive force of the intermediate rotor permanent magnet (4) is obtained as follows: in, is the amplitude of the j-th pole component in the permanent magnet magnetomotive force, is the number of pole pairs of the intermediate rotor permanent magnet, is the intermediate rotor position angle, is the intermediate rotor angular velocity, t For time.

3. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 2, characterized in that: Under the modulation of the permanent magnet magnetomotive force, the Fourier decomposition expression of the magnetic permeance of the outer stator (1) and the inner stator (5) teeth is: in is the permeance function of the outer stator tooth, is the constant component in the outer stator tooth permeability, is the amplitude of the component of the kth pair of poles in the outer stator tooth permeance, is the number of outer stator teeth, is the permeance function of the inner stator tooth, is the constant component in the inner stator tooth permeability, is the amplitude of the component of the first pair of poles in the inner stator tooth permeability, is the number of inner stator teeth, The angle between the center lines of the inner and outer stator teeth.

4. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 3 is characterized in that: The air gap magnetic flux density in the air gap between the outer stator (1) and the inner stator (5) is obtained by multiplying the initial permanent magnet magnetomotive force of the intermediate rotor permanent magnet (4) by the magnetic permeance of the teeth of the inner stator (5) and the outer stator (1), and the expression is: ， in is the air gap flux density of the outer stator, is the air gap flux density of the inner stator. Through the modulation of the initial permanent magnet magnetomotive force by the inner and outer stator teeth, the main air gap flux density in the inner and outer stator air gap flux density is Pole-to-pole, outer stator air gap magnetic flux harmonic is Pole to pole, the inner stator air gap magnetic flux harmonic is Antipodes.

5. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 4, characterized in that: The functional expressions of the outer stator armature winding (2) and the inner stator armature winding (6) are: in is the outer stator armature winding function, is the inner stator armature winding function, is the number of turns of the outer stator armature winding, is the number of turns of the inner stator armature winding, n is the number of harmonics in the winding function.

6. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 5, characterized in that: The no-load flux of the outer stator armature winding (2) and the inner stator armature winding (6) is expressed as: in is the flux linkage of the outer stator armature winding, is the winding factor of the outer stator armature winding, is the inner diameter of the outer stator, is the motor shaft length; is the inner stator armature winding flux, is the winding factor of the inner stator armature winding, is the inner stator outer diameter, l It is a multiple of the number of internal stator slots.

7. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 6, characterized in that: The no-load back electromotive force induced by the outer stator armature winding (2) and the inner stator armature winding (6) is obtained by taking the derivative of the no-load flux linkage, and its expression is: in e 0( t ) is the no-load back electromotive force induced by the outer stator armature winding, e i ( t ) is the no-load back electromotive force induced by the inner stator armature winding, k w is the winding factor of the winding.

8. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 7, characterized in that: The amplitude expression of the no-load back electromotive force generated by the outer stator armature winding (2) and the inner stator armature winding (6) is: in is the amplitude of the no-load back electromotive force generated by the outer stator armature winding, is the amplitude of the no-load back electromotive force generated by the inner stator armature winding, F 1 is the fundamental magnetomotive force.

9. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 8, characterized in that: The expression for the average torque of the electromagnetic torque generated by the outer stator armature winding (2) and the inner stator armature winding (6) is: in is the average torque of the electromagnetic torque generated by the outer stator armature winding, is the amplitude of the phase current flowing through the outer stator armature winding, is the average torque of the electromagnetic torque generated by the inner stator armature winding, is the amplitude of the phase current flowing through the inner stator armature winding, P oe is the electromagnetic power generated by the outer stator armature winding, P ie It is the electromagnetic power generated by the inner stator armature winding.

10. The five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor according to claim 1, characterized in that: The outer stator (1) and the inner stator (5) are respectively provided with electrical ports.

Images