Permanent magnet motor construction method based on armature winding construction model

Abstract

The invention discloses a permanent magnet motor construction method based on an armature winding construction model, and belongs to the field of permanent magnet motors, the method combines motor electromagnetic performance requirements and corresponding air gap flux density harmonic characteristics, analyzes armature harmonic characteristics required by electromechanical energy conversion, and reversely deduces a specific armature winding structure; an armature unit construction model with guiding significance is provided, and the electromechanical energy conversion capability of armature harmonic waves is fully exerted; under application occasions of multi-working harmonic waves or multi-electric port integration and the like, the motor constructed by the method has an armature unit structure with unequal turns, irregular distribution or multiple groups of windings, the armature unit can generate armature harmonic waves with specific times, amplitudes and phases, odd-numbered and even-numbered armature harmonic waves can be simultaneously generated in one set of windings, and the armature unit structure is simple in structure and convenient to operate. And meanwhile, electromechanical energy conversion is participated.

Description

Technical Field

[0001] The present invention belongs to the field of permanent magnet motors, and more specifically, relates to a permanent magnet motor construction method based on an armature winding construction model. Background Art

[0002] Permanent magnet motors, as actuators of electric drive systems, are widely used in high-end equipment such as high-end CNC machine tools, new energy power generation, and aerospace. In recent years, with the improvement of performance requirements for high-end equipment and the rapid expansion of the application field of electrified equipment, higher and higher requirements have been placed on the performance indicators of permanent magnet motors, such as volume, weight, power quality, etc.

[0003] Traditional permanent magnet synchronous motors work based on single magnetic flux density harmonics, and the armature winding only uses a single harmonic to participate in the output of average torque. The structure of the vernier permanent magnet motor is similar to that of the permanent magnet synchronous motor, but it is based on the principle of magnetic field modulation and uses two working magnetic fields to convert electromechanical energy to generate torque. Studies have shown that under the same electromagnetic load level, its torque density can reach nearly twice that of the permanent magnet synchronous motor. At present, when designing conventional permanent magnet motors and vernier permanent magnet motors, the windings are wound in the stator slots, and the windings must be designed according to the pole slot matching and the traditional phase splitting method. This results in the solidification of the armature harmonic components of the permanent magnet motor, and it is difficult to generate armature harmonics with a specific pole pair number, phase, and amplitude, which cannot meet the performance requirements of high torque quality or specific applications. Summary of the invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a permanent magnet motor construction method based on the armature winding construction model, which can solve the problems in the prior art such as the solidification of the harmonic components of the permanent magnet motor armature, difficulty in directional control, difficulty in achieving motor structure innovation, torque performance improvement, and multi-electric port integration.

[0005] To achieve the above object, according to a first aspect of the present invention, a permanent magnet motor construction method based on an armature winding construction model is provided, comprising:

[0006] According to the harmonic order and phase of each harmonic required by the permanent magnet motor to be constructed to meet the target electromagnetic performance requirements, N w '(θ s ) or G w (θ s ) is adjusted, and the phase or amplitude of the target subharmonic in N is adjusted according to the adjusted w '(θ s ) or G w (θ s ) respectively obtain the coil structure and spatial distribution characteristics of the A-phase winding of the permanent magnet motor to be constructed; according to the symmetry of the three-phase winding, obtain the coil structure and spatial distribution characteristics of the B-phase and C-phase windings of the permanent magnet motor to be constructed;

[0007] Among them, θ s N is any mechanical angle rotated counterclockwise from the central axis of a basic unit model of the A-phase winding as the original axis in the circumferential direction. w '(θ s ) is the armature basic unit function of the A-phase winding, which is used to characterize the coil structure of the A-phase winding, wherein the coil structure includes the span and number of turns of the coil, θ y is the span, N c is the number of turns, v is the harmonic order;

[0008] G w (θ s ) is the spatial constructor of the A-phase winding, which is used to characterize the spatial distribution characteristics of the A-phase winding, wherein the spatial distribution characteristics include the position of the coil in space and the series connection mode between the coils, G w (θ s ) includes one or more impulse functions, the spatial angle of each impulse function represents the position of a group of coils in space, and the amplitude of the impulse function is positive, indicating that the current flow direction of the coil is to generate a magnetomotive force from the rotor to the stator under the right-hand rule, otherwise the current flow direction of the coil is to generate a magnetomotive force from the stator to the rotor under the right-hand rule, and the coils with the same current flow direction are connected in forward series, and the coils with different current flow directions are connected in reverse series;

[0009] To N w '(θ s ) to adjust the phase of a harmonic in the system, including:

[0010] If it is necessary to invert the vth harmonic, and the number of "zero points" greater than v and closest to v is 2k / (θ y ), then θ y Increase to β1θ y ; or, if it is necessary to invert the vth harmonic, and the number of "zero points" that are smaller than v and closest to v is 2k / (θ y ), then θ y Narrowing to β2θ y ; The "zero point" number is the harmonic number with an amplitude of 0;

[0011] For G w (θ s ) to adjust the phase of a harmonic in the system, including:

[0012] If the phase of the harmonic v needs to be changed by ε, then G w (θ s )’s spatial angle translation ε / v.

[0013] To N w '(θs ) to adjust the amplitude of a certain harmonic in the equation, including:

[0014] When v is in the interval [4k / (θ y ), (4k+2) / (θ y )], then θ y Increase to δ1θ y , thus changing the amplitude of the vth harmonic from sin(vθ y / π)N c / v increases to sin(vδ1θ y / π)N c / v; y Zooming down to δ2θ y , so that n w '(v) amplitude The amplitude of the harmonic v is given by sin(vθ y / π)N c / v is reduced to sin(vδ2θ y / π)N c / v;

[0015] When v is in the interval [(4k-2) / (θ y ), 4k / (θ y )], then θ y Zooming down to δ1θ y , thus changing the amplitude of the vth harmonic from sin(vθ y / π)N c / v increases to sin(vδ1θ y / π)N c / v; y Increase to δ2θ y , thus changing the amplitude of the vth harmonic from sin(vθ y / π)N c / v is reduced to sin(vδ2θ y / π)N c / v;

[0016] For G w (θ s ) to adjust the amplitude of a certain harmonic in the equation, including:

[0017] If it is necessary to change the amplitude of the harmonic v from g w (v)cos(vθ g ) becomes g w (v)cos(vθ g +vΔθ g ), then G w (θ s )Translation Δθ g ; g w (v) is Gw (θ s )’s frequency domain function.

[0018] According to a second aspect of the present invention, there is provided an electronic device, comprising: a computer-readable storage medium and a processor;

[0019] The computer-readable storage medium is used to store executable instructions;

[0020] The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the method as described in the first aspect.

[0021] According to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a processor to execute the method as described in the first aspect.

[0022] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0023] The method provided by the present invention combines the electromagnetic performance requirements of the motor and the corresponding air gap magnetic flux harmonic characteristics, analyzes the armature harmonic characteristics required for electromechanical energy conversion, and reversely deduces the specific armature winding structure, proposes an armature unit construction model with guiding significance, and gives full play to the electromechanical energy conversion capability of the armature harmonics; in application scenarios such as multiple working harmonics or multi-electric port integration, the motor constructed by this method has an armature unit structure with unequal turns, irregular distribution or multiple groups of windings (with different currents passing through), and the armature unit can generate armature harmonics of specific order, amplitude and phase, and can simultaneously generate odd and even armature harmonics in a set of windings, and simultaneously participate in electromechanical energy conversion.

[0024] As a preferred solution, the method provided by the present invention, after obtaining the armature winding structure, also optimizes the stator core structure in which the irregular armature winding is embedded, and the main teeth are alternately arranged in width and narrowness. The narrower main teeth provide a larger slot space for the winding coil, thereby improving the slot fill rate of the winding coil.

[0025] As a preferred solution, the method provided by the present invention arranges auxiliary teeth next to the main teeth to ensure that the slot width of the slot where the coil is located does not exceed the slot width threshold, thereby avoiding serious magnetic leakage caused by too large a slot width. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A flowchart of a permanent magnet motor construction method based on an armature unit construction model provided by an embodiment of the present invention;

[0027] Figure 2 The embodiment of the present invention provides w (θs ) Schematic diagram of the spatial angle of translation ε / v;

[0028] Figure 3 An armature harmonic control and armature unit construction method based on a construction model provided in an embodiment of the present invention;

[0029] Figure 4 A schematic diagram of the structure of an armature unit provided in an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of the modulation unit structure provided by an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of the overall structure of a stator provided by a permanent magnet motor of the structure provided in an embodiment of the present invention;

[0032] Figure 7 A schematic diagram of the overall structure of a rotor provided by a permanent magnet motor of the structure provided in an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the overall structure of a permanent magnet motor provided in an embodiment of the present invention.

[0034] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0035] 1 is the winding, 2 is the stator, 3 is the rotor, 4 is the permanent magnet array, 5 is the rotating shaft, and 6 is the modulation unit. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] The embodiment of the present invention provides a permanent magnet motor construction method based on an armature winding construction model, such as Figure 1 As shown, including:

[0038] According to the harmonic order and phase of each harmonic required by the permanent magnet motor to be constructed to meet the target electromagnetic performance requirements, N w '(θ s ) or G w (θ s ) is adjusted, and the phase or amplitude of the target subharmonic in N is adjusted according to the adjusted w '(θ s ) or G w (θs ) respectively obtain the coil structure and spatial distribution characteristics of the A-phase winding of the permanent magnet motor to be constructed; according to the symmetry of the three-phase winding, obtain the coil structure and spatial distribution characteristics of the B-phase and C-phase windings of the permanent magnet motor to be constructed.

[0039] The permanent magnet motor to be constructed comprises an armature unit, a permanent magnet array and a modulation unit.

[0040] The following is an explanation of the construction process of the armature winding structure model:

[0041] 1) The armature unit construction model is proposed, which includes the basic unit model, i.e., a single set of coils, and the spatial construction model, i.e., the spatial position of the coil in the circumferential direction [0,2π] and the direction of the central axis, and the armature unit function N is obtained. w (θ s ) and the basic unit function N w '(θ s ), space constructor G w (θ s ), where θ s is the circumferential spatial position of the armature unit of the A-phase winding in the stationary coordinate system. The specific meaning is: assuming that the central axis of a basic unit model of the A-phase winding is the original axis (i.e., the reference axis) in the circumferential direction, any mechanical angle θ rotated counterclockwise from the original axis s Defined as the spatial position in the circumferential direction, the armature unit function of the A-phase winding is:

[0042] N w (θ s )=N' w (θ s )*G w (θ s ) (1)

[0043] Among them, the basic unit function N w '(θ s ) is used to characterize the spatial distribution characteristics of the coil, N w '(θ s ) parameters include the span θ y and number of turns N c , so N w '(θ s ) can be specifically expressed as:

[0044]

[0045] Space constructor G w (θ s ) is composed of a single or multiple impulse functions, where a single impulse function is G w (θ s), its frequency domain function contains all harmonics from 0 to +∞, and the amplitude of each harmonic is 1. In permanent magnet motors, only one or several specific harmonics of the armature are usually required to participate in the electromechanical energy conversion process. Therefore, the minimum harmonic order of the armature is G w (θ s ) has a minimum number of repetition cycles T of the impulse function. One cycle contains n (1≤n≤T) impulse functions. The spatial angle where each impulse function is located represents the position of a group of coils in space. The absolute value of the impulse function amplitude in each cycle is the same as G. A positive impulse function amplitude indicates that the current flow direction of the coil is to generate a magnetomotive force from the rotor to the stator under the right-hand rule. Conversely, a negative impulse function amplitude indicates that the current flow direction of the coil is to generate a magnetomotive force from the stator to the rotor under the right-hand rule. The current flow direction describes the series connection between different coils, that is, coils with the same flow direction are connected in forward series, and coils with different flow directions are connected in reverse series.

[0046] 2) According to the Fourier transform characteristics, in the frequency domain, the armature unit frequency domain function n w (v) and the basic unit frequency domain function n w '(v) and spatial construction frequency domain function g w (v) Satisfy the rules in (2):

[0047] n w (v) = n' w (v)×g w (v) (2)

[0048] Where v is the harmonic order, n' w (v) Theoretically, it contains all harmonics, and g w (v) Contains only harmonics of specific orders.

[0049] 3) According to the motor performance requirements, the armature unit frequency domain function n is obtained w Then, the linearity, translation, and scalability of Fourier transform are used to adjust N separately or simultaneously. w '(θ s )、n w '(v) and G w (θ s ), g w (v) To achieve the phase and amplitude control of a certain harmonic of the armature operation, such as weakening the amplitude of a specific harmonic, adjusting the phase of a specific harmonic, etc., so as to achieve an ideal armature unit under the specified electromagnetic performance requirements. w (v) Harmonic composition.

[0050] To regulate the phase or amplitude of a certain armature operating harmonic, it can be discussed in the following specific cases:

[0051] (1) Regulating the harmonic phase

[0052] 1) Regulating N w ’(θ s )、n w ’(v)

[0053] According to formula (1), the expression of each harmonic can be derived as:

[0054]

[0055] It can be seen that n w ’(v) is a sine function, and its amplitude depends on N c / v, that is, N c only affects the amplitude of the harmonic and does not affect the phase characteristics of the harmonic. θ y will affect both the amplitude and phase of each harmonic. At this time, the harmonic order with an amplitude of 0, also known as the "zero point" order, is 2k / θ y (k = 0, 1, 2…), and the harmonic phases on both sides of the zero point are opposite.

[0056] Therefore, the scalability of the Fourier transform can be used to regulate N w ’(θ s ) to achieve the phase inversion of a certain harmonic in n w ’(v). For example, to change the phase of the v1th harmonic, 1) assume that the "zero point" order greater than v and closest to it is 2k / (θ y ). By stretching N w ’(θ s ) by β1 times (that is, θ y increases to β1θ y ), the "zero point" order is compressed to 2k / (β1θ y ), and 2k / (β1θ y ) < v. At this time, the vth harmonic is phase-inverted; 2) assume that the "zero point" order less than v and closest to it is 2k / (θ y ). By compressing N w ’(θ s ) by β2 times (that is, θ y is reduced to β2θ y ), the "zero point" order is stretched to 2k / (β2θ y ), and 2k / (β2θ y ) > v. At this time, the vth harmonic is phase-inverted.

[0057] 2) Regulating G w (θ s )、g w(v)

[0058] Known space constructor G w (θ s ) is composed of T (T ≥ 1) impulse function groups. The impulse function in a single cycle can be single or multiple. The frequency domain function g can be realized by using the linearity and translation of Fourier transform w (v) Phase change of specific harmonics. The specific method is as follows:

[0059] i. Translation: Assume G w (θ s ) has an initial phase of θ g , translated by Δθ in the stationary coordinate system g , then the initial phase becomes θ g +Δθ g According to the Fourier transform translation, the frequency domain function g w (v) The phase of each harmonic will change by vΔθ g For example, if we need to change the phase of the vth harmonic of the armature by ε, we can know from the above analysis that G w (θ s ) can be translated by the spatial angle of ε / v. w (θ s ) as an example, let G w (θ s )Translate the spatial angle of ε / v as Figure 2 shown.

[0060] ii. Linearity combined with translation: According to linearity, G w (θ s ) can be equivalent to ∑G wi (θ s ), where the maximum value of i is the number of impulse functions. However, for the convenience of calculation, G is usually w (θ s ) is equivalent to the linear sum of two or three spatial subconstructors, namely G w1 (θ s )+G w2 (θ s ) or G w1 (θ s )+G w2 (θ s )+G w3 (θ s ). Further, combined with the translation in i, each space subconstructor G wi (θ s ) can be used as the object of translation, that is, there are 2 to 3 design parameters for the control of harmonic phase. The more design parameters there are, the higher the degree of freedom for controlling the harmonic phase.

[0061] G w (θ s )=G w1 (θ s )+G w2 (θ s ) as an example, assuming G w1 (θ s ), G w2 (θ s ) are θ g1 and θ g2 For example, if the phase of the v1 harmonic needs to be changed by ε1 and the phase of the v2 harmonic needs to be changed by ε2, then G w1 (θ s ), G w2 (θ s ) of the translation phase Δθ g1 , Δθ g2 Satisfies condition (4). It can be seen that if the number of harmonics of the directional control phase is n ≥ 2, the number of subspace constructors will not be less than n.

[0062]

[0063] 3) Simultaneous regulation of N w '(θ s )、n w '(v) and G w (θ s ), g w (v)

[0064] According to the conclusions in 1) and 2), regulating N w '(θ s )、n w '(v) Mainly use the scalability of Fourier transform to control G w (θ s ), g w (v) mainly uses the translation of Fourier transform (linearity combined with translation mainly relies on translation to adjust the phase). Therefore, when the number of harmonics to be regulated increases and the phase requirements increase, methods 1) and 2) can be combined to simultaneously regulate N w '(θ s )、n w '(v) and G w (θ s ), g w (v) The specific rules are the same as the above method.

[0065] If the number of harmonics that need to be controlled is n ≥ 4, then K ≥ 2n. If v1, v2, …, v KThe phases of the subharmonics change one by one ε1, ε2, ..., ε K , then N w1 '(θ s ), N w2 '(θ s ),…,N wK '(θ s ) y β1θ y1 , β2θ y2 , ..., β K θ yK , and satisfy the relationship:

[0066]

[0067] sgn is a custom function used to reflect n w1 '、n w2 ', ..., n wK 'Harmonic phase, n w '>0, sgn(n w ')=0,n w '<0, sgn(n w ')=π.

[0068] (2) Controlling harmonic amplitude

[0069] 1) Regulation of N w '(θ s )、n w '(v)

[0070] From formula (3), we can know that n w The magnitude of '(v) also depends on N c / v and sin(vθ y / π). On the one hand, changing N c The amplitude of all harmonics will be changed to the same extent. On the other hand, the scalability of Fourier transform can be used to control N w '(θ s ) can achieve n w '(v) Control of the amplitude of a certain harmonic.

[0071] For example, when v is in the interval [4k / (θ y ), (4k+2) / (θ y )], by stretching N w '(θ s )δ1 times (that is, θ y Increase to δ1θ y ), at this time n w '(v) will increase in magnitude to sin(v1δ1θ y / π)Nc / v; by compressing N w '(θ s )δ2 times (that is, θ y Zooming down to δ2θ y ), at this time n w '(v) will be reduced to sin(vδ2θ y / π)N c / v.

[0072] For example, when v is in the interval [(4k-2) / (θ y ), 4k / (θ y )], by compressing N w '(θ s )δ1 times (that is, θ y Zooming down to δ1θ y ), at this time n w '(v) will increase in magnitude to sin(vδ1θ y / π)N c / v; by stretching N w '(θ s )δ2 times (that is, θ y Increase to δ2θ y ), at this time n w '(v) will be reduced to sin(vδ2θ y / π)N c / v.

[0073] 2) Regulation of G w (θ s ), g w (v)

[0074] Known space constructor G w (θ s ) is composed of T (T ≥ 1) impulse function groups. The impulse function in a single cycle can be single or multiple, and the absolute value of the amplitude is the same as G. Using the linearity and translation of Fourier transform, the frequency domain function g can be realized w (v) Changes in the amplitude of harmonics of a specific order.

[0075] The specific method is as follows:

[0076] According to linearity, G w (θ s ) can be equivalent to ∑G wi (θ s ), where the maximum value of i is the number of impulse functions. For the convenience of calculation, G is usually w (θ s ) is equivalent to the linear sum of two or three spatial subconstructors, namely G w1 (θs )+G w2 (θ s ) or G w1 (θ s )+G w2 (θ s )+G w3 (θ s ), the absolute value of the amplitude of the impulse function of each subspace constructor is G1, G2…Gi. At this time, each space subconstructor G wi (θ s ) can be used as the object of translation, that is, there are 4 to 6 design parameters for the regulation of the armature harmonic amplitude. The more design parameters there are, the higher the degree of freedom for regulating the harmonic amplitude.

[0077] Assume G w (θ s ) is 0, with G w (θ s )=G w1 (θ s )+G w2 (θ s ) as an example. Among them, G w1 (θ s ) has an initial phase of θ g1 , G w2 (θ s ) has an initial phase of θ g2 , then g w The harmonic amplitude of (v) is equal to g w1 (v)cos(vθ g1 )+g w2 (v)cos(vθ g2 ). Assume G w1 (θ s )Translation Δθ g1 , the initial phase becomes θ g1 +Δθ g1 According to the Fourier transform translation, the frequency domain function g w1 (v) The phase of each harmonic will change by vΔθ g1 Assume G w2 (θ s )Translation Δθ g2 , the initial phase becomes θ g2 +Δθ g2 , frequency domain function g w2 (v) The phase of each harmonic will change by vΔθ g2 At this time g w The harmonic amplitude of (v) is equal to g w1 (v)cos(vθ g1 +vΔθ g1 )+gw2 (v)cos(vθ g2 +vΔθ g2 ), at the same time, G w1 (θ s ) and G w2 (θ s ) can also be adjusted. Under the premise that the total number of turns of each phase winding remains unchanged, the condition of |G1+ΔG1|+|G2+ΔG2| remaining unchanged must be observed.

[0078] For example, if the amplitude of the armature harmonics v1 to v4 needs to be changed by α1 to α4, then G w1 (θ s ), G w2 (θ s ) of the translation phase Δθ g1 , Δθ g2 , the amplitude G1, G2 changes ΔG1, ΔG2 satisfy condition (5). It can be seen that if the number of harmonics of the directional control amplitude n ≥ 4, the number of subspace constructors is not less than 2n.

[0079]

[0080] 3) Simultaneous regulation of N w '(θ s )、n w '(v) and G w (θ s ), g w (v)

[0081] According to the conclusions in 1) and 2), regulating N w '(θ s )、n w '(v) Mainly use the scalability of Fourier transform to control G w (θ s ), g w (v) mainly uses the linearity of Fourier transform. Therefore, when the number of harmonics to be regulated increases and the amplitude requirements increase, methods 1) and 2) can be combined to simultaneously regulate N w '(θ s )、n w '(v) and G w (θ s ), g w (v) The specific rules are the same as the above method.

[0082] If the number of harmonics whose amplitude needs to be regulated is n≥4, then K≥2n. If v1, v2, …, v K The amplitudes of the subharmonics change one by one, α1, α2, ..., α K , then Nw1 '(θ s ), N w2 '(θ s ),…,N wK '(θ s ) y β1θ y1 , β2θ y2 , ..., β K θ yK , and satisfy the relationship:

[0083]

[0084] Among them, G1, G2, …, G K G w1 (θ s ), G w2 (θ s ),…,G wK (θ s )’s amplitude.

[0085] Finally, the new N w '(θ s ) and G w (θ s ), combined with formula (1), the ideal armature unit function N is derived w (θ s ). Since N w '(θ s ) and G w (θ s ) correspond to the exact coil structure and distribution characteristics, so the N w (θ s ) also has a directly corresponding armature unit structure.

[0086] The permanent magnet motor includes a coaxially sleeved rotor, a stator, a winding, a rotating shaft and a permanent magnet array, wherein the stator and the winding are formed by the permanent magnet motor construction method based on the armature unit construction model as described above; the modulation unit is integrated with the iron core wound by the armature to form a stator structure, an air gap is formed between the permanent magnet array and the stator, and the permanent magnet array is radially magnetized and adjacent permanent magnets are magnetized in opposite directions.

[0087] Preferably, after obtaining the coil structure and spatial distribution characteristics of each phase winding of the permanent magnet motor to be constructed, the method further includes:

[0088] According to the coil structure and spatial distribution characteristics of each phase winding, the width of the tooth portion of the tooth slot structure where the winding is located is designed to provide winding space for the coil.

[0089] By optimizing the width of the tooth portion of the tooth slot structure where the winding is located, a larger slot space is provided for the coil, thereby improving the slot fill rate of the winding coil.

[0090] Preferably, after optimizing the width of the tooth portion of the tooth slot structure where the winding is located, the method further includes:

[0091] By setting auxiliary teeth next to the main teeth, the slot width of the coil slot is ensured not to exceed the slot width threshold, thereby avoiding serious magnetic leakage caused by too large slot width. The slot width threshold can be set based on experience, such as 3°.

[0092] The method provided by the present invention is further described below with a specific example. Figure 3-7 shown.

[0093] Operation S1 : determining the order of working harmonics and the phase of each harmonic required by the permanent magnet motor to be constructed according to the working principle of the motor.

[0094] The interaction between the permanent magnet and the modulation unit produces magnetic flux harmonics, and the magnetic flux harmonic order v and amplitude B can be obtained. v , initial phase φ v , the rotation direction sgn1(v) is defined as formula (6). According to the electromechanical energy conversion mechanism, the order of the armature working harmonic is the same as the order of the magnetic flux harmonic v, and the rotation direction is also the same as the rotation direction of the magnetic flux harmonic sgn1(v). Combined with the amplitude of the armature harmonic n v and the initial phase θ v , the analytical expression of the motor fundamental back EMF e1 with respect to the above parameters can be calculated, as shown in equation (7). If the pole pair number is defined as 1 as the fundamental wave, then the vth armature harmonic corresponds to the armature harmonic with v pole pairs.

[0095]

[0096] Among them, P pm and P m Represents the number of pole pairs of the permanent magnet array and the modulation unit respectively. Counterclockwise is designated as the positive rotation direction, sgn = +1; clockwise is designated as the negative rotation direction, sgn = -1.

[0097]

[0098] Among them, D g is the diameter corresponding to the motor air gap; L is the effective shaft length of the motor; Ω is the mechanical rotation angular velocity of the rotor; t is the time.

[0099] From formula (7), we can see that if we want to obtain the maximum back-EMF amplitude E1, the initial phase θ of each working harmonic v and φ vThe difference is the same and the maximum value is π / 2. At this time, E1 can be expressed as:

[0100]

[0101] When the motor saturation is ignored, the relationship between the motor average torque T and the back electromotive force amplitude E1 satisfies the relationship of formula (5), so E1 can be used to reflect the size of the average torque.

[0102]

[0103] Among them, I m Indicates the current amplitude passing through the phase winding.

[0104] In this embodiment, the number of rotor permanent magnet pole pairs is taken as the single harmonic P pm =7 as an example, the initial phase is -π / 2, the modulation unit includes a constant term permeance and multiple permeance harmonics, mainly P m1 =3, P m2 =6, P m3 =9, P m4 =12, the initial phases of the constant permeance and each harmonic permeance are 0, π, π, π, 0 respectively, and the number of turns of the single-phase winding series coil is N s =200. According to the magnetic field modulation principle, the permanent magnet and the modulation unit will modulate to produce 1st, 2nd, 4th, 5th, and 7th magnetic density harmonics, and the initial phase φ v They are π / 2, -π / 2, π / 2, π / 2, -π / 2 respectively. According to formula (7), the armature operating harmonics are 1, 2, 4, 5, 7 harmonics, and the initial phase θ v They are 0, 0, 0, π, 0 respectively. It can be seen that the minimum order of the armature harmonic is 1 at this time, and the period number of the space constructor is T = 1. Generating armature harmonics of specific phases and odd and even orders in a set of windings at the same time is the special feature and difficulty of this embodiment.

[0105] The permanent magnet motor includes a stator 2 wound with a winding 1, a permanent magnet array 4, a rotor 3, a rotating shaft 6, and a modulation unit 7. Specifically, for example, the stator, the rotor, and the rotating shaft are coaxially sleeved from the outside to the inside, or the rotor, the rotating shaft, and the stator are coaxially sleeved from the outside to the inside. An air gap is formed between the rotor and the stator, and a permanent magnet array is embedded in the rotor near the air gap, and a modulation unit is arranged on the stator near the air gap. In this embodiment, Figure 6-Figure 8 The stator, rotor, and rotating shaft shown in the figure are coaxially arranged from the outside to the inside, a permanent magnet array is embedded on the rotor near the air gap surface, and a modulation unit is arranged on the stator near the air gap surface as an example to illustrate the specific operation process of the permanent magnet motor construction method based on the armature unit construction model.

[0106] Operation S2, based on the structural model of the armature unit, converts the design of the armature unit into the design of two elements: a basic unit model (a single set of coils) and a spatial structural model (the spatial distribution and axial direction of the coils). Figure 3 As shown in the figure, the proposed armature unit construction model shows that the armature unit structure is the result of the interaction between the basic unit and the spatial construction model, which is reflected in the analytical function as formula (1), that is, the armature unit function N w Equal to the basic unit function N' w With the space constructor G w According to the Fourier transform characteristics, the distribution of armature unit harmonics is equal to the basic unit function n' in the frequency domain w and the space constructor g w Therefore, by regulating the design n' w and g w By knowing the phase, amplitude and other characteristic parameters of the working subharmonics, the armature working harmonics designed in S1 can be obtained.

[0107] According to the linearity of Fourier transform, the armature unit function N w Can be equivalent to N' w1 *G w1 +N' w2 *G w2 ,like Figure 3 As shown. First, due to the space constructor G w The period number T is 1, and the subspace constructor G w1 and G w2 The number of cycles is also 1, and it consists of only a single impulse function with amplitudes G1 and G2 respectively. In this case, g w1 With g w2 will contain all harmonics. Assume g w1 With g w2 The initial phase is 0, the amplitude G1 = G2 = 1, then g w1 and g w2 The phase of each harmonic is the same, and the two coils are actually located at the same position in space. Assume N' w1 and N' w2 The initial span angle θ y1 ,θ y2 Equal to 60°, number of turns N c1 =N c2 =100, then n' w 1 and n' w2, the phase and amplitude of each harmonic are the same, and the phases of the 1st, 2nd, 4th, 5th, and 7th harmonics are 0, 0, 0, π, and π respectively. In order to generate the armature working harmonics that meet the requirements of S1, that is, to generate the 1st, 2nd, 4th, 5th, and 7th harmonics with phases of 0, 0, 0, π, π respectively, and the amplitudes of the 2nd and 4th harmonics are close to the initial values, it is necessary to simultaneously control n' w and g w , thereby achieving the regulation of harmonic phase and amplitude.

[0108] According to the design goal, n w1 '、n w2 ' and g w1 , g w2 The key parameters of satisfy formula (10). It is worth noting that sgn is a custom function used to reflect n w1 '、n w2 'The harmonic phase, that is, n w '>0, sgn(n w ')=0,n w '<0, sgn(n w ')=π.

[0109]

[0110] After solving equation (10), we get β1 = 1.31, Δθ g1 =0°、β2=0.69、Δθ g2 =180°, ΔG1=0.09, ΔG2=-0.09. The 5% in the last two formulas in formula (10) is because the amplitude of the 2nd and 4th harmonics should be close to the initial value by no less than 95%, otherwise the original main working harmonics (2nd and 4th) will be weakened.

[0111] In this embodiment, the corresponding armature basic unit spectrum is as follows: Figure 3 As shown. Among them, n' w1 and n' w2 The second and fourth harmonics of the wave have unchanged phases, and their amplitudes have opposite trends and similar degrees, thus maintaining the amplitude basically unchanged. w1 and n' w2 The amplitudes of the 1st, 5th, and 7th odd harmonics are significantly different, especially the 5th and 7th harmonic phase changes are π. Combined with the opposite phases of the odd harmonics of g1 and g2, n' w1 g w1 with n' w2 g w2 The sum of these will produce the 5th and 7th armature harmonics with significant amplitudes. Finally, n' w1 g w1 with n' w2 gw2 The sum is the armature unit frequency domain function n w , the working harmonic characteristics meet the requirements of S1, n' w1 , g w1 with n' w2 , g w2 The corresponding spatial domain function N' w1 , G w1 With N' w2 , G w2 The parameters of can be obtained by solving equation (10).

[0112] Operation S3, according to the armature basic unit function and space constructor obtained in S2, the corresponding coil structure and spatial distribution characteristics can be obtained, such as Figure 3 As shown. N' w1 *G w1 With N' w2 *G w2 The superposition sum corresponds to the forward series connection of two sets of coils, ultimately forming an armature unit structure that meets the requirements.

[0113] According to an embodiment of the present invention, the permanent magnet motor construction method further includes operation S4, optimizing the tooth width of the tooth slot structure where the winding is located, and the narrower main teeth provide a larger slot space for the winding coil, thereby improving the slot fill rate of the winding coil. At the same time, auxiliary teeth are arranged next to the main teeth to avoid serious magnetic leakage caused by too large a slot width. The final armature unit structure is as follows Figure 4 shown.

[0114] Figure 5 The modulation unit in the stator is integrated with the winding and its slot structure to form a stator structure, and the stator slot structure is optimized in detail to increase the output torque. The optimized structure is as follows: Figure 6 Further, the structure of the rotor and the permanent magnet array inside the rotor is as shown in Figure 7 As shown, the structure of the permanent magnet motor finally formed by nesting is as follows. Figure 8 It can be understood that this example is illustrated by a permanent magnet motor with an inner rotor and an outer stator, and the method provided by the present invention is also applicable to a permanent magnet motor with an inner stator and an outer rotor.

[0115] That is, if Figure 4-8 As shown, the permanent magnet motor includes a coaxially sleeved rotor 3, a stator 2, a rotating shaft 5 and a permanent magnet array 4. A modulation unit 6 is provided on the side of the stator 2 opposite to the rotor 3. The stator 2 and the winding 1 are formed as follows. Figure 1-Figure 2The permanent magnet motor construction method based on the armature unit construction model shown is formed; the permanent magnet array 4 is arranged opposite to the modulation unit 6, an air gap is formed between the two, the permanent magnet array 4 is radially magnetized and the magnetization directions of adjacent permanent magnets are opposite. The permanent magnet motor also includes a winding 1, which is wound around the stator teeth. The stator is composed of two groups of stator teeth of different widths alternating, and has a total of six auxiliary teeth.

[0116] In summary, the present invention establishes a structural model of the armature unit (winding and the iron core structure on which it is wound) of a permanent magnet motor, and on this basis proposes a method for controlling armature harmonics, the purpose of which is to construct a quantitative relationship between the armature unit structural parameters, spatial distribution characteristics, and characteristic parameters such as the armature harmonic order, phase, and amplitude; using air gap magnetic density as an intermediate quantity, deriving analytical expressions of performance parameters such as no-load back electromotive force and average torque with respect to armature harmonics, and solving the armature harmonic spectrum under specific electromagnetic performance targets; finally, according to the structural model of the armature unit, a directionally constructed armature unit structure that meets the performance requirements is constructed.

[0117] An embodiment of the present invention provides an electronic device, including: a computer-readable storage medium and a processor;

[0118] The computer-readable storage medium is used to store executable instructions;

[0119] The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the method described in any of the above embodiments.

[0120] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method described in any of the above embodiments.

[0121] An embodiment of the present invention provides a computer program product, including a computer program or instructions, and when the computer program or instructions are executed by a processor, the method described in any of the above embodiments is implemented.

[0122] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A permanent magnet motor construction method based on an armature winding construction model, characterized in that: include: According to the harmonic order and phase of each harmonic required by the permanent magnet motor to be constructed to meet the target electromagnetic performance requirements, N w '(θ s ) or G w (θ s ) is adjusted, and the phase or amplitude of the target subharmonic in N is adjusted according to the adjusted w '(θ s ) or G w (θ s ) respectively obtain the coil structure and spatial distribution characteristics of the A-phase winding of the permanent magnet motor to be constructed; according to the symmetry of the three-phase winding, obtain the coil structure and spatial distribution characteristics of the B-phase and C-phase windings of the permanent magnet motor to be constructed; Among them, θ s N is any mechanical angle rotated counterclockwise from the central axis of a basic unit model of the A-phase winding as the original axis in the circumferential direction. w '(θ s ) is the armature basic unit function of the A-phase winding, which is used to characterize the coil structure of the A-phase winding, wherein the coil structure includes the span and number of turns of the coil, θ y is the span, N c is the number of turns, v is the harmonic order; G w (θ s ) is the spatial constructor of the A-phase winding, which is used to characterize the spatial distribution characteristics of the A-phase winding, wherein the spatial distribution characteristics include the position of the coil in space and the series connection mode between the coils, G w (θ s ) includes one or more impulse functions, the spatial angle of each impulse function represents the position of a group of coils in space, and the amplitude of the impulse function is positive, indicating that the current flow direction of the coil is to generate a magnetomotive force from the rotor to the stator under the right-hand rule, otherwise the current flow direction of the coil is to generate a magnetomotive force from the stator to the rotor under the right-hand rule, and the coils with the same current flow direction are connected in forward series, and the coils with different current flow directions are connected in reverse series; To N w '(θ s ) to adjust the phase of a harmonic in the system, including: If it is necessary to invert the vth harmonic, and the number of "zero points" greater than v and closest to v is 2k / (θ y ), then θ y Increase to β1θ y ; or, if it is necessary to invert the vth harmonic, and the "zero point" that is smaller than v and closest to v is 2k / (θ y ), then θ y Narrowing to β2θ y ; The "zero point" number is the harmonic number with an amplitude of 0; For G w (θ s ) to adjust the phase of a harmonic in the system, including: If the phase of the harmonic v needs to be changed by ε, then G w (θ s )’s spatial angle translation ε / v; To N w '(θ s ) to adjust the amplitude of a certain harmonic in the equation, including: When v is in the interval [4k / (θ y ), (4k+2) / (θ y )], then θ y Increase to δ1θ y , thus changing the amplitude of the vth harmonic from sin(vθ y / π)N c / v increases to sin(vδ1θ y / π)N c / v; y Zooming down to δ2θ y , so that n w '(v) amplitude The amplitude of the harmonic v is given by sin(vθ y / π)N c / v is reduced to sin(vδ2θ y / π)N c / v; When v is in the interval [(4k-2) / (θ y ), 4k / (θ y )], then θ y Zooming down to δ1θ y , thus changing the amplitude of the vth harmonic from sin(vθ y / π)N c / v increases to sin(vδ1θ y / π)N c / v; y Increase to δ2θ y , thus changing the amplitude of the vth harmonic from sin(vθ y / π)N c / v is reduced to sin(vδ2θ y / π)N c / v; For G w (θ s ) to adjust the amplitude of a certain harmonic in the equation, including: If it is necessary to change the amplitude of the harmonic v from g w (v)cos(vθ g ) becomes g w (v)cos(vθ g +vΔθ g ), then G w (θ s )Translation Δθ g ; g w (v) is G w (θ s )’s frequency domain function.

2. The method according to claim 1, characterized in that Also includes: If the phase or amplitude of multiple harmonics needs to be adjusted, N w '(θ s ) or G w (θ s ) is split into the linear sum of K subspace constructors and sub-armature basic unit functions, that is, let G w (θ s )=∑G wi (θ s ) or N w '(θ s )=∑N wi '(θ s ), to adjust the phase or amplitude of multiple harmonics respectively, i = 1, 2, …, K.

3. The method according to claim 2, characterized in that If the number of harmonics to be controlled is n ≥ 2, then K ≥ n. If v1, v2, ..., v K The phases of the subharmonics change one by one ε1, ε2, ..., ε K , then G w1 (θ s ), G w2 (θ s ),…,G wK (θ s ) of the translation phase Δθ g1 , Δθ g2 ,…,Δθ gK Satisfies the relationship:

4. The method according to claim 2, characterized in that If the number of harmonics whose amplitude needs to be regulated is n≥4, then K≥2n. If v1, v2, …, v K The amplitudes of the subharmonics change one by one, α1, α2, ..., α K , then G w1 (θ s ), G w2 (θ s ),…,G wK (θ s ) of the translation phase Δθ g1 , Δθ g2 ,…,Δθ gK , amplitude G1, G2, ..., G K , and the amplitude changes ΔG1, ΔG2, …, ΔG K Satisfies the relationship: Among them, θ y1 ,θ y2 ,…,θ yK are the spans of the 1st, 2nd, ..., Kth groups of coils, θ g1 ,θ g2 ,…,θ gK G w1 (θ s ), G w2 (θ s ),…,G wK (θ s )’s initial phase.

5. The method according to claim 2, characterized in that If the number of harmonics that need to be controlled is n ≥ 4, then K ≥ 2n. If v1, v2, …, v K The phases of the subharmonics change one by one ε1, ε2, ..., ε K , then N w1 '(θ s ), N w2 '(θ s ),…,N wK '(θ s ) y β1θ y1 , β2θ y2 , ..., β K θ yK , and satisfy the relationship: sgn is a custom function used to reflect n w1 '、n w2 ', ..., n wK 'Harmonic phase, n w '>0, sgn(n w ')=0,n w '<0, sgn(n w ')=π.

6. The method according to claim 2, characterized in that If the number of harmonics whose amplitude needs to be regulated is n≥4, then K≥2n. If v1, v2, …, v K The amplitudes of the subharmonics change one by one, α1, α2, ..., α K , then N w1 '(θ s ), N w2 '(θ s ),…,N wK '(θ s ) y β1θ y1 , β2θ y2 , ..., β K θ yK , and satisfy the relationship: Among them, G1, G2, …, G K G w1 (θ s ), G w2 (θ s ),…,G wK (θ s )’s amplitude.

7. The method according to claim 1, characterized in that After obtaining the coil structure and spatial distribution characteristics of each phase winding of the permanent magnet motor to be constructed, it also includes: According to the coil structure and spatial distribution characteristics of each phase winding, the width of the tooth portion of the tooth slot structure where the winding is located is designed to provide winding space for the coil.

8. The method according to claim 1, characterized in that After the optimization of the width of the tooth portion of the tooth slot structure where the winding is located, the method further includes: By arranging auxiliary teeth next to the main teeth, it is ensured that the slot width of the coil does not exceed the threshold.

9. An electronic device, characterized in that: include: A computer readable storage medium and a processor; The computer-readable storage medium is used to store executable instructions; The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method according to any one of claims 1 to 8.

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