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

Abstract

The present invention discloses a five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor, which relates to the technical field of permanent magnet motors. The motor includes an outer stator, an outer stator armature winding, an intermediate rotor, intermediate rotor permanent magnets, an inner stator, an inner stator armature winding, and a rotating shaft. The motor realizes multiple operating modes of the motor through the flexible control of the inner and outer stator windings, meeting the requirements of different driving conditions of electric vehicles. By making full use of multiple pairs of air-gap magnetic density harmonics inside and outside, the torque output capacity and power factor of the motor are improved. The motor also has a certain safety redundancy. When problems occur in the inner stator winding or the outer stator winding, it only needs to disconnect the circuits of all the inner stator windings or the outer stator windings, and only supply power to the normal winding circuits, and the motor can operate normally. Compared with ordinary three-phase motors, this motor can achieve a larger power output and has a fault tolerance function at the same time.

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 achieve breakthrough progress in battery technology in the short term, the optimization of the 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 conditions, 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:

[0006] A five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor adopts an inner and outer double-stator and an intermediate single-rotor structure, and 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:

[0007] 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;

[0008] The tooth grooves of the outer stator and the tooth grooves of the inner stator serve as the field modulation units of the motor, and the number of both is 20;

[0009] The outer stator armature winding and the inner stator armature winding, 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;

[0010] 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.

[0011] Further, 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:

[0012]

[0013] Among them, 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.

[0014] Further, under the modulation of the permanent magnet magnetomotive force, the expression of the Fourier decomposition of the permeance of the outer stator and inner stator teeth is:

[0015]

[0016] Among them 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 permeance of the inner stator teeth, is the l amplitude of the component of the number of inner stator teeth, angle between the center lines of the inner and outer stator teeth.

[0017] Further, the air-gap magnetic density in the air gaps of 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 outer stator teeth, and the expression is:

[0018] ,

[0019] Among them 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 air-gap magnetic densities of the inner and outer stators is For the opposite poles, the harmonic of the air-gap magnetic density of the outer stator is For the opposite poles, the harmonic of the air-gap magnetic density of the inner stator is For the opposite poles.

[0020] Furthermore, the functional expressions of the outer stator armature winding and the inner stator armature winding are:

[0021]

[0022] 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.

[0023] Furthermore, the expressions of the no-load magnetic flux linkage of the outer stator armature winding and the inner stator armature winding are:

[0024]

[0025] 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.

[0026] Furthermore, 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 linkage, and its expression is:

[0027]

[0028] 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.

[0029] Furthermore, the amplitude expressions of the no-load back electromotive force generated by the outer stator armature winding and the inner stator armature winding are:

[0030]

[0031] Among them 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.

[0032] 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:

[0033]

[0034] Among them 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.

[0035] Furthermore, the outer stator and the inner stator are respectively provided with electrical ports.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] The five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by the present invention can realize various operation modes of the motor through flexible control of its inner and outer stator windings, meeting the requirements of different driving conditions of electric vehicles.

[0038] The five-phase fault-tolerant double-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.

[0039] The five-phase fault-tolerant double-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.

[0040] The five-phase fault-tolerant double-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.

[0041] For the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by the present invention, when the magnetic fields are the same and the armature currents are equal in magnitude, the motor can generate a greater power and torque output compared with a conventional three-phase permanent magnet motor.

[0042] In summary, the present invention provides a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor, which uses the inner and outer electrical ports of the double stator to achieve cooperative excitation and multi-mode operation of the motor. It can not only achieve a higher torque density and power density, but also realize different driving conditions, and at the same time has a high safety redundancy performance and fault tolerance performance, providing technical support for the drive application of new energy electric vehicles and having high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

[0044] Figure 1 It is a schematic structural diagram of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0045] Figure 2 It is a waveform diagram of the speed, current, back electromotive force, and torque of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention when operating at high speed and low torque.

[0046] Figure 3 It is a waveform diagram of the speed, current, back electromotive force, and torque of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention when operating at low speed and high torque.

[0047] Figure 4 It is an air-gap magnetic flux density waveform diagram of the inner stator of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0048] Figure 5 It is an air-gap magnetic flux density waveform diagram of the outer stator of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0049] Figure 6 It is a harmonic distribution diagram of the air-gap magnetic flux density of the inner stator of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0050] Figure 7 It is a harmonic distribution diagram of the air-gap magnetic flux density of the outer stator of a five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0051] Figure 8 The speed, current, back electromotive force, and torque waveform diagrams of the inner stator winding powered and the outer stator winding disconnected for a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0052] Figure 9 The speed, current, back electromotive force, and torque waveform diagrams of the inner stator winding disconnected and the outer stator winding powered for a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention.

[0053] Figure 10 The speed, current, back electromotive force, and torque waveform diagrams when the C-phase winding of the outer stator of a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by an embodiment of the invention is disconnected and the other phases are normally powered.

[0054] 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 dual-stator field modulation permanent magnet synchronous motor provided by an embodiment of the invention are disconnected and the other phases are normally powered.

[0055] Figure 12 The power and torque outputs of a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by an embodiment of the invention and a common three-phase permanent magnet motor when the magnetic fields are the same and the armature current magnitudes are equal. Specific embodiments

[0056] 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 shall fall within the protection scope of the present application.

[0057] The core of the present application is to propose a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor, which can not only achieve a 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.

[0058] In order to enable those skilled in the art to better understand the solutions of the present application, the present application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0059] Figure 1 The structural schematic diagram of a five-phase fault-tolerant dual-stator field modulation permanent magnet synchronous motor provided by an embodiment of the present invention, as Figure 1As shown in the figure, the five-phase fault-tolerant double-stator magnetic 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.

[0060] The motor adopts a structure of an inner and outer double-stator and a single intermediate rotor. The number of slots of the outer stator 1 and the inner stator 5 is 20, and the number of pole pairs of the intermediate rotor permanent magnet 4 is 22 pairs of poles.

[0061] 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 1 shown, the A-phase of the outer stator winding is designed according to the arrangement 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 according to the arrangement structure as Figure 1 shown to be able to generate a 4-pole magnetic field.

[0062] The structure of the intermediate rotor permanent magnet 4 of the motor adopts a V-V structure with good magnetic flux concentrating effect. As Figure 1 shown, four adjacent rotor permanent magnets are arranged according to an approximate V-V structure. The design of the V-structure permanent magnet makes the magnetic field lines concentrate in the V-shaped structure, thereby enhancing the magnetic flux density of 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 field lines are gathered into the working air gap, reducing the magnetic leakage phenomenon, and thus improving the utilization rate of the magnetic field.

[0063] 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.

[0064] 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. If the number of pole pairs is smaller, the amount of permanent magnet materials required is less, the magnetic field strength inside the motor is relatively smaller, and the output torque is smaller.

[0065] Performing Fourier decomposition on the initial permanent magnet magnetic motive force of the intermediate rotor permanent magnet, the expression of the permanent magnet magnetic motive force of the intermediate rotor permanent magnet is obtained as:

[0066]

[0067] where, is the amplitude of the component of the j-th pair of poles in the permanent magnet magnetic motive 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, tis time.

[0068] The magnetic field modulation unit of the motor is the inner stator tooth grooves and the outer stator tooth grooves. Under the modulation of the permanent magnet magnetomotive force, the expression of the Fourier decomposition of the permeance of the outer stator and inner stator teeth is:

[0069]

[0070] 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 k - th pair of pole components 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 permeance of the inner stator teeth, is the l amplitude of the component of the number of inner stator teeth, angle between the center lines of the inner and outer stator teeth.

[0071] Furthermore, multiplying the initial permanent magnet magnetomotive force of the intermediate rotor permanent magnet by the 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:

[0072] ,

[0073] 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 - gaps 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.

[0074] 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.

[0075] 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 to produce 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:

[0076]

[0077] 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.

[0078] Furthermore, the expressions for the no-load magnetic fluxes of the outer stator armature winding and the inner stator armature winding are:

[0079]

[0080] 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.

[0081] 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:

[0082]

[0083] where e 0 ( t ) is the no-load back electromotive force induced in the outer stator armature winding, e i ([[]]END]] t ) is the no-load back electromotive force induced in the inner stator armature winding, k w is the winding factor of the winding.

[0084] It can be seen 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 ω r of the motor rotor 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 a pole pair number of P m , P m -Nost , P m +N ost The time periods of the air-gap magnetic flux density harmonics are the same. This means that although there are a large number of rich air-gap magnetic flux density harmonics in the motor air gap, the spatially air-gap magnetic flux density harmonics with the same modulation can generate no-load magnetic link and no-load back electromotive force harmonics with the same frequency, thereby improving the utilization rate of motor harmonics.

[0085] When the permanent magnet magnetomotive force harmonic 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:

[0086]

[0087] 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.

[0088] 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 double-stator field modulation 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:

[0089]

[0090] 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.

[0091] It can be seen from the above formula that the five-phase fault-tolerant double-stator field modulation permanent magnet synchronous motor of the present invention makes full use of the inner and outer multiple pairs of air-gap magnetic flux density harmonics and improves the torque output ability of the motor.

[0092] The pole-slot combination of the motor conforms to the magnetic field modulation principle, and the relationship satisfied 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 magnetic field modulation unit. In addition, combining 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 magnetic field modulation unit of the three-phase magnetic field modulation 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 magnetic field modulation unit of the five-phase magnetic field modulation 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 magnetic field modulation unit of the six-phase magnetic field modulation permanent magnet motor are selected as 2, 26, 24. After repeated experiments, the present invention preferably selects a five-phase magnetic field modulation 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 magnetic field modulation unit are 2, 22, 20.

[0093] In a specific implementation, for the five-phase fault-tolerant dual-stator magnetic field modulation 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 inner and outer stators to achieve cooperative excitation and multi-mode operation of the motor.

[0094] As Figure 2 shown, when the armature currents of the inner stator armature winding and the outer stator armature winding both flow through 5 A, the motor speed is controlled at 1500 revolutions per minute, and the average torque output by the motor is 64 N·m. This operating condition corresponds to the situation of the vehicle running at a constant speed with high speed and low torque on a straight road. The current, back electromotive force, speed, and torque waveform diagrams of the motor of the present invention are as Figure 2 shown.

[0095] As Figure 3 shown, when the armature currents of the inner stator armature winding and the outer stator armature winding both flow through 15 A, the motor speed is controlled at 500 revolutions per minute, and the average torque output by the motor is 154 N·m. This operating condition corresponds to the situation of the vehicle running with low speed and 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.

[0096] In a specific implementation, for the five-phase fault-tolerant dual-stator magnetic 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 ability and power factor of the motor can be improved.

[0097] As Figure 4As shown, the armature current of 5 A flows through both the inner stator armature winding and the outer stator armature winding. The motor speed is controlled at 1500 revolutions per minute, and the magnitude of the air-gap magnetic flux 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.

[0098] As Figure 5 shown, the armature current of 5 A flows through both the inner stator armature winding and the outer stator armature winding. The motor speed is controlled at 1500 revolutions per minute, and the magnitude of the air-gap magnetic flux 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.

[0099] 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 flux density in the air-gap magnetic flux density of the inner stator is 22 pole pairs, and the other air-gap magnetic flux density harmonics are mainly 2 and 42 pole pairs, verifying that the magnetic field modulation motor can make full use of multiple pairs of air-gap magnetic flux density harmonics of the inner stator, thereby improving the torque output ability of the motor.

[0100] As Figure 7 shown, when the number of pole pairs of the middle rotor permanent magnet is 22 and the number of teeth and slots of the outer stator is 20, the main air-gap magnetic flux density in the air-gap magnetic flux density of the outer stator is 22 pole pairs, and the other air-gap magnetic flux density harmonics are mainly 2 and 42 pole pairs, verifying that the magnetic field modulation motor can make full use of multiple pairs of air-gap magnetic flux density harmonics of the outer stator, thereby improving the torque output ability of the motor.

[0101] In specific implementation, the five-phase fault-tolerant dual-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, only the circuits of all the inner stator armature windings or the outer stator armature windings need to be disconnected, and only the normal winding circuits are powered, and the motor can operate normally.

[0102] 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 only the inner stator of the dual-stator magnetic field modulation permanent magnet synchronous motor is working.

[0103] 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 only the outer stator of the dual-stator magnetic field modulation permanent magnet synchronous motor is working.

[0104] In a specific implementation, the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor has a fault-tolerant 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 operate through the fault-tolerant control strategy.

[0105] As Figure 10 shown, when the outer stator phase C winding is disconnected and 5 A current flows through the other phase windings, 5 A current flows through all phases of the inner stator armature winding. The motor operates at 1500 revolutions per minute, and the average torque output of the motor is 58 N·m. This operating condition corresponds to the high-speed and low-torque operating condition of the vehicle when the outer stator single-phase winding of the double-stator magnetic field modulation permanent magnet synchronous motor fails and both the outer stator and the inner stator are working.

[0106] As Figure 11 shown, when the inner stator phases A and B windings are disconnected and 5 A current flows through the other phase windings, 5 A current flows through all phases of the outer stator armature winding. The motor operates at 1500 revolutions per minute, and the average torque output of the motor is 52 N·m. This operating condition corresponds to the high-speed and low-torque operating condition of the vehicle when the inner stator two-phase windings of the double-stator magnetic field modulation permanent magnet synchronous motor fail and both the outer stator and the inner stator are working.

[0107] In a specific implementation, for the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor, when the magnetic field is the same and the armature current magnitude is equal, the motor can produce a greater power and torque output compared to a conventional three-phase permanent magnet motor.

[0108] As Figure 12 shown, when 5 A armature current flows through both the inner stator armature winding and the outer stator armature winding of the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor, 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 output waveform of the conventional three-phase permanent magnet motor, (b) is the power output waveform of the conventional three-phase permanent magnet motor, (c) is the average torque output waveform of the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor, and (d) is the power output waveform of the five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor.

[0109] The above has introduced in detail the five-phase fault-tolerant dual-stator magnetic field modulation permanent magnet synchronous motor provided by the present application. The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts between the various embodiments, reference can be made to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and reference can be made to the description in the method part for the relevant parts. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor, characterized in that Adopt an inner and outer double-stator and an intermediate single-rotor structure, including 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), where: The intermediate rotor permanent magnet (4) 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 (1) and the inner stator (5) serve as the magnetic field modulation units of the motor, and their numbers are both 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 grooves of the outer stator (1) and the inner stator (5), and are designed according to the 5-phase 2-pair-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; 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: Among them, 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; Under the modulation of the permanent magnet magnetomotive force, the expressions of the Fourier decomposition of the permeance of the teeth of the outer stator (1) and the inner stator (5) are: wherein 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 k-th pair of pole components 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 permeance of the inner stator teeth, is the l amplitude of the pair of pole components in the 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.

2. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 1, wherein The air-gap magnetic density in the air gaps of 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 permeance of the teeth of the inner stator (5) and the outer stator (1), and the expression is: ， Among them 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 teeth of the inner and outer stators, the main air-gap magnetic density in the air-gap magnetic densities of the inner and outer stators is pole pairs, the air-gap magnetic density harmonics of the outer stator are pole pairs, and the air-gap magnetic density harmonics of the inner stator are pole pairs.

3. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 2, wherein The functional expressions of the outer stator armature winding (2) and the inner stator armature winding (6) are: wherein 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.

4. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 3, characterized in that The expressions of the no-load magnetic flux linkage of the outer stator armature winding (2) and the inner stator armature winding (6) are: Among them 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.

5. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 4, 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 differentiating the no-load magnetic flux linkage, and its expression is: Among them 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.

6. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 5, characterized in that, The amplitude expressions of the no-load back electromotive force generated by the outer stator armature winding (2) and the inner stator armature winding (6) are: wherein 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.

7. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 6, characterized in that, The expression of the average torque of the electromagnetic torque generated by the outer stator armature winding (2) and the inner stator armature winding (6) is: Among them 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.

8. The five-phase fault-tolerant double-stator magnetic field modulation permanent magnet synchronous motor according to claim 1, wherein The outer stator (1) and the inner stator (5) are respectively provided with electrical ports.

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