CN111327174A - Coreless long stator permanent magnet linear synchronous motor - Google Patents
Coreless long stator permanent magnet linear synchronous motor Download PDFInfo
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- CN111327174A CN111327174A CN202010187518.6A CN202010187518A CN111327174A CN 111327174 A CN111327174 A CN 111327174A CN 202010187518 A CN202010187518 A CN 202010187518A CN 111327174 A CN111327174 A CN 111327174A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
- H02K41/02—Linear motors; Sectional motors
- H02K41/03—Synchronous motors; Motors moving step by step; Reluctance motors
- H02K41/031—Synchronous motors; Motors moving step by step; Reluctance motors of the permanent magnet type
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
- H02K2201/03—Machines characterised by aspects of the air-gap between rotor and stator
Abstract
A coreless long stator permanent magnet linear synchronous motor comprises a long primary, an air gap and a permanent magnet pole. The long stator is composed of three-phase or multi-phase windings and is fixed in a winding fixing device made of non-magnetic conductive and non-conductive materials. The short secondary is a permanent magnetic pole and is opposite to the long primary winding, and an air gap of the motor is arranged between the long primary and the permanent magnetic secondary. The long primary winding is formed by winding a flat cable, the secondary permanent magnetic pole adopts a Halbach permanent magnetic array which is in an unequal-height structure, the permanent magnetic array is placed in a sleeve made of a non-magnetic conducting material, and a plurality of magnetic blocks with similar magnetizing directions are placed in the same sleeve cavity to be fixed. The long primary winding, the air gap and the permanent magnet magnetic pole form the coreless long stator permanent magnet linear synchronous motor. The coreless long-stator permanent magnet linear synchronous motor can effectively improve the thrust density.
Description
Technical Field
The invention relates to a permanent magnet linear motor, in particular to an ironless permanent magnet linear synchronous motor with long primary and short secondary for linear driving.
Background
A linear motor is a transmission device that directly converts electric energy into mechanical energy for linear motion without any intermediate conversion mechanism. The linear motor can be used in any application where linear drive is required.
The permanent magnet linear synchronous motor has the main advantages that the permanent magnet is adopted as the magnetic pole, the magnet exciting coil is omitted, the electric excitation is not needed, the efficiency of the motor can be improved, and the temperature rise is reduced. And the structure is simple, the structure is firm and durable, and high-speed and high-acceleration linear driving can be realized. However, a large normal suction force is generated between the primary and the secondary of the single-side permanent magnet linear synchronous motor with an iron core, and in some application occasions, for example, when the single-side permanent magnet linear synchronous motor is used for driving a magnetic suspension train, the normal suction force causes large interference to the magnetic suspension force and can increase the energy requirement of the magnetic suspension system, and the normal suction force needs to be avoided. In order to avoid the normal suction force generated between the primary iron core and the secondary iron core, an ironless permanent magnet linear motor is required.
Compared with a motor with an iron core, the iron-core-free motor has the main problems that the electromagnetic air gap of the motor is large, the magnetic conductance of a magnetic circuit is small, the magnetic leakage is large, high excitation magnetic potential is needed, the energy density of the motor is low, and therefore the thrust density is also low. On the other hand, because the permanent magnetic pole is a rotor, in order to improve the excitation magnetic potential, more permanent magnets are needed, so that the dead weight of the rotor is increased, and the thrust weight ratio of the motor is as follows: the thrust/permanent magnet weight is low. For example, in The article "investment of Single-ended iron Linear Synchronous Motor Based on Permanent Magnet Synchronous Motor Used for medical speed motors" (The 11th International Symposium on Linear motors for industrial Applications (LDIA 2017)), The thrust-weight ratio of The Single-Sided iron-coreless long stator Permanent Magnet Linear Synchronous Motor developed for medium-speed Maglev trains is only 13.82N/kg, The thrust density is very low, and The weight of The vehicle-mounted Permanent Magnet reaches more than 400 kg.
The thrust-weight ratio is a key index for measuring or comparing the performance of the long-stator permanent magnet linear synchronous motor for linear driving. The improvement of the power density and the thrust-weight ratio of the coreless motor is one of the keys for improving the performance of the motor.
Fig. 5 is a schematic structural diagram of a single-side coreless long-stator linear synchronous motor in the prior art. Figure 17 is a calculated field distribution for a prior art motor using an 8-module Halbach permanent magnet array, with only one turn of the armature winding of a circular conductor shown to facilitate visual inspection of the field distribution. The distance between the upper part of the conductor and the lower pole surface of the magnetic pole is an electromagnetic air gap. As can be seen from fig. 17, the magnetic field below the permanent magnet pole is divergent due to the coreless core, and the magnetic lines of force become gradually sparse, which indicates that the magnetic field decays rapidly as the distance from the lower side of the pole face increases. Fig. 18 is a graph of the magnetic induction B below the pole face of the permanent magnet pole as a function of distance, a decreasing graph, showing that the magnetic field decreases as the distance increases. As can be seen from fig. 18, the diameter of the circular armature conductor of the conventional motor is 20.4mm, the distance between the upper part of the conductor and the pole face is 25.3mm, B at the upper part of the circular armature conductor is 0.4136T, B at the lower part of the conductor is reduced to 0.3014T, and the magnetic induction B from top to bottom is reduced by 27%. This indicates that the magnetic induction B of the key chain conductor decreases with the increase in the conductor thickness due to the non-uniform magnetic field under the pole face, and the thrust also decreases, resulting in a lower energy conversion efficiency and a lower thrust density of the motor. Therefore, it is necessary to optimize the magnetic circuit structure and the armature conductor arrangement mode to improve the power density and the thrust-weight ratio of the motor.
Disclosure of Invention
In order to overcome the defects of the prior art and improve the thrust density and the thrust weight ratio of the coreless long-stator permanent magnet linear synchronous motor, the invention provides a single-side coreless long-stator permanent magnet linear synchronous motor. The invention improves the prior art from two aspects of permanent magnetic poles and stator winding distribution, effectively improves the air gap magnetic field, thereby improving the thrust density of the motor and improving the applicability of the coreless long stator permanent magnetic linear synchronous motor in linear driving.
The invention relates to a coreless long-stator permanent magnet linear synchronous motor which comprises a primary stage, a secondary stage and an air gap of a motor. The motor is in a long primary and short secondary structure, and the motor is in an iron-core-free structure, and the long primary and the short secondary do not contain ferromagnetic materials. The long primary three-phase or multi-phase armature winding of the motor is embedded in the winding fixing device to form a long stator of the motor. The winding fixture is made of a non-magnetically conductive, non-electrically conductive material, such as an epoxy material. The short secondary is a permanent magnetic pole, is made of permanent magnetic materials and adopts a Halbach permanent magnetic array arrangement structure. The magnetic blocks in the permanent magnet array are fixed through a sleeve, and the sleeve is made of non-magnetic materials such as aluminum alloy and non-magnetic stainless steel. The permanent magnet pole is a short mover. And an air gap of the motor is arranged between the long stator and the short rotor.
The long primary armature winding is three-phase or multi-phase and is in a flattened arrangement with armature conductors arrayed on the armature surface. The arrangement mode of the windings is a single-layer wave winding. The long primary armature winding is made of flat cables, the cable conductors are flat single-core conductors or flat two-core round conductors or multi-core round conductors, and the outer portions of the conductors are covered with insulating layers. The cable conductor material is copper, aluminum or other conductors.
The short secondary permanent magnetic pole adopts a Halbach permanent magnetic array structure.
In the Halbach permanent magnet array with the non-equal-height structure, the height of the magnet blocks magnetized along the oblique line direction is larger than the height of the magnet blocks magnetized along the transverse direction and the vertical direction.
A plurality of magnetic blocks with the same or similar magnetizing directions in the permanent magnet array are placed in the same fixed sleeve to be fixed. The sleeve is made of aluminum material, and can also be a cylindrical structure made of other non-magnetic materials such as non-magnetic stainless steel, epoxy, glass fiber reinforced plastic, wood and the like. The fixed sleeve is provided with the permanent magnets of the non-equal height Halbach permanent magnet array, the heights of the inner cavities of the fixed sleeve are equal, and the vacant part of the inner cavity of the sleeve provided with the magnet with the lower height is filled with filling blocks made of non-magnetic-conductive materials.
The magnetic block is sealed in the sleeve cavity by adopting the baffle plates made of non-magnetic materials at the two ends of the sleeve.
As can be seen from the calculation formula dF of the thrust dF of the current element Idl in the magnetic field, which is Idl × B, if the thrust of the motor is to be increased, the magnetic induction B at the armature conductor and the linear load I of the motor need to be increased, where dl is the length of the current element.
Compared with the coreless long stator permanent magnet linear synchronous motor in the prior art, the long stator armature winding is arranged in a flat mode, under the condition that the areas of the conductors are kept the same, the armature conductors in the motor in the prior art are flattened, the conductors are arranged on the surface of the armature, the electromagnetic air gap, namely the distance from the surface of the permanent magnet to the surface of the conductor is effectively reduced, the magnetic induction intensity B reaching all the positions of the armature conductors is made to be as large as possible, and the thrust is improved. The thrust density can be increased if the same volume or weight of permanent magnet material is used.
Compared with the Halbach permanent magnet array with the equal-height structure adopted by the motor in the prior art, the Halbach permanent magnet array with the unequal-height structure can obtain the air gap magnetic field with higher fundamental wave magnetic induction intensity and more sinusoidal waveform, and is also beneficial to improving the thrust density.
The invention puts several magnetic blocks with similar magnetizing directions into the same sleeve cavity for fixation, compared with the prior art that each magnetic block of the motor is put into one sleeve cavity, the invention reduces the quantity and the volume of the middle interval of the fixed sleeve, correspondingly increases the volume of the permanent magnetic block, is beneficial to improving the magnetic induction intensity of the air gap and reduces the cost of the permanent magnetic fixing device. The invention adopts three improved schemes to work together to improve the thrust density of the motor and improve the performance of the motor.
Drawings
Fig. 1 is a cross-sectional view of an embodiment 1 of the motor of the present invention, τ being the pole pitch;
FIG. 2 is a schematic diagram of a three-phase single-wave winding arrangement for a prior art motor and a motor of the present invention;
figure 3 is a Halbach permanent magnet pole figure of 8 modules per cycle for example 1 of the present invention;
FIG. 4 is a three-dimensional view of an aluminum sleeve of example 1 of the present invention;
FIG. 5 is a cross-sectional view of a prior art ironless long stator permanent magnet linear synchronous motor;
FIG. 6 is a view of a permanent magnet pole and sleeve of a prior art motor;
FIG. 7 is a three-dimensional view of a prior art motor and aluminum sleeve of embodiment 2 of the present invention;
FIG. 8 is a single round conductor cable of a prior art motor;
fig. 9 is a schematic view of a single core flat conductor cable of the present invention;
FIG. 10a is a schematic view of a flat type two-core round conductor cable according to example 1 of the present invention;
FIG. 10b is a schematic view of a flat three-core round conductor cable according to the present invention;
FIG. 10c is a schematic view of an arrangement of a flat multi-core round conductor cable according to the present invention, which uses 8 cores as an example;
FIG. 11 is a schematic diagram showing a comparison between a single-core round conductor cable and a flat type two-core conductor cable for a long stator winding;
FIG. 12 is a comparison of the calculated air gap field generated by a single core round conductor cable and a flat double core round conductor cable;
FIG. 13 is a comparison of thrust calculations for a motor using a single core round conductor cable and a flat dual core round conductor cable;
FIG. 14 is a comparison of thrust calculation results for a permanent magnet array and a flat dual-core round conductor cable motor using two magnet block mounting methods;
FIG. 15 is a schematic view of a non-contour Halbach permanent magnet array;
FIG. 16 is a calculation result of the influence of the height difference change of non-equal-height Halbach permanent magnet array magnetic blocks on the thrust of a motor, wherein the height difference change of the magnetic blocks d is in millimeters;
FIG. 17 is a field calculation graph of a prior art motor with 8 modules per cycle of Halbach array permanent magnet poles;
FIG. 18 is a graph of the variation of magnetic induction of a Halbach array permanent magnet pole of 8 modules per cycle with a negative Y coordinate for a prior art motor;
in the figure, 1 is a long primary of an ironless long stator permanent magnet linear synchronous motor, 2 is an air gap of the motor, and 3 is a short secondary. 11 long primary armature windings, 12 armature winding fixing devices, 13 single-core round conductors of motor cables in the prior art, 14 insulating layers of the motor cables in the prior art, 15 single-core flat conductors of the flat cables with the improved structures, 16 multi-core round conductors of the flat cables with the improved structures, 31 unit magnetic blocks of Halbach permanent magnetic poles, 32 magnetic block fixing sleeves, 33 filling blocks and 34 sleeve cavities.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
The coreless long-stator permanent magnet linear synchronous motor is of a long primary structure and a short secondary structure, and the long primary structure and the short secondary structure do not contain ferromagnetic materials. The long primary is embedded in the winding fixing device by three-phase or multi-phase armature winding to form the long stator of the motor. The winding fixture is made of a non-magnetically conductive, non-electrically conductive material, such as an epoxy material. The short secondary is made of permanent magnet material and adopts Halbach permanent magnet array form. The magnetic blocks in the permanent magnet array are fixed by sleeves, and the sleeves are made of non-magnetic materials such as aluminum alloy, non-magnetic stainless steel and the like. The permanent magnet pole is a short mover. And an air gap of the motor is arranged between the long stator and the short rotor.
The long primary armature windings may be three or more phases, the long primary armature windings being in a flattened arrangement with the armature conductors arrayed on the armature surface. The arrangement mode of the windings is a single-layer wave winding. The long primary armature winding is made of flat cables, each cable is composed of a flat single-core conductor, or two-core round conductors or multi-core round conductors which are arranged into a flat shape, and an outer insulating layer of the flat single-core conductor or the multi-core round conductors, and the cable conductor is made of copper, aluminum or other conductors.
Because the magnetic field generated by the permanent magnetic pole of the coreless motor is attenuated rapidly along with the increase of the distance, in order to improve the power density of the primary and the secondary and improve the thrust weight ratio, the primary conductor can adopt a strip conductor and is laid on the surface of the armature, so that the magnetic induction intensity B at the conductor is maximized. However, the width-to-height ratio a/b of the section of the strip conductor is large, so that the shaping difficulty of the end part of the winding is increased, great inconvenience is brought to the winding laying of a long stator motor, and the winding laying cost is increased greatly. The multi-core round conductor flat cable is most favorable in consideration of cost performance of a motor, so that when the number q of each phase slot of each pole is 1, only 1 cable is continuously laid for each phase, only 3 cables are used for three phases, a long stator armature winding can be wound, the long stator winding only needs to be firmly fixed, and technological treatment such as paint dipping is not needed. The long stator armature winding has the simplest manufacturing process and the lowest manufacturing cost. The width and height ratio of the multi-core round conductor flat cable and the core number of the conductors in the cable need to be optimally designed according to parameters of an air gap, a pole pitch, a vehicle speed, a winding fixing device and the like of a specific motor.
The invention adopts the round conductor with multiple cores and smaller cross section to manufacture the flat cable and winds the flat cable to manufacture the armature winding, thereby not only enabling the conductors in the armature winding to be positioned in the area with higher magnetic induction intensity, but also reducing the skin effect generated when the conductor with large cross section passes through alternating current, being beneficial to reducing the resistance loss of a stator and improving the efficiency of a motor, and the advantage can be fully embodied when the armature winding passes through higher frequency current.
The short rotor permanent magnetic poles adopt a Halbach permanent magnetic array structure, and the number of the magnetic blocks of each magnetic pole pitch tau is 2, 3, 4, … … n and the like. The magnetizing angle of each magnetic block is changed according to the principle that adjacent magnetic blocks have a difference of 2 pi/m in sequence, wherein m is the number of magnetic blocks in each pair of poles, namely each period, and m is 2 n. In principle, the larger the number of magnetic blocks under one pole pitch is, the better the sine shape of the generated air gap magnetic field is, and the smaller the leakage magnetic field is. However, in terms of magnetic pole manufacturing process, the more the number of magnetic blocks per pole pitch is, the more difficult the manufacturing process is, so the requirement of air gap magnetic field and the manufacturing cost need to be comprehensively considered for selecting the value of n. From the viewpoint of cost performance, the array of n-4 is most often used.
In the Halbach permanent magnetic array with the non-equal-height structure, the height of the magnetic blocks magnetized along the oblique line direction is larger than that of the magnetic blocks magnetized along the transverse direction and the vertical direction.
The permanent magnet array is fixed by an aluminum sleeve, and can also be fixed by a cylindrical structure made of other non-magnetic materials such as non-magnetic stainless steel, epoxy, glass fiber reinforced plastic, wood and the like. Several magnetic blocks with similar or same magnetizing directions are put into the same sleeve cavity for fixing.
The height of the inner cavity of the fixed sleeve made of the non-magnetic material is equal, and the vacant part of the inner cavity of the sleeve filled with the magnetic blocks with lower height is filled with the filling block made of the non-magnetic material.
The magnetic block is sealed in the sleeve cavity by adopting the baffle plates made of non-magnetic materials at the two ends of the sleeve.
Example 1
The long primary 1 of the motor of the invention is formed by a three-phase armature winding 11 embedded in a winding fixture 12. The long primary 1 of the machine is also referred to as the long stator. The winding fixture 12 is made of an epoxy material, although other non-magnetic, non-conductive materials may be used. The short secondary 3 is a permanent magnetic pole, is made of permanent magnetic materials and adopts a Halbach permanent magnetic array structure. The short secondary 3 is also called a short mover. The magnetic blocks 31 in the permanent magnet array are fixed by sleeves 32, and the sleeves 32 are made of aluminum alloy. The permanent magnet pole is a short mover 3. An air gap 2 of the motor is arranged between the long stator 1 and the short rotor 3.
The long primary armature winding 11 is three-phase, the long primary winding is in a flattened arrangement, and the armature conductors are arranged on the armature surface. The long primary armature winding 11 is made of a flat type two-core round conductor cable, as shown in fig. 10 a. The flat cable with multiple round conductors can be used under the condition of keeping the conductor area of the cable the same. Fig. 10b is a schematic structural view of a three-core round conductor flat cable, and fig. 10c is a schematic structural view of an 8-core round conductor flat cable.
Simulation calculation results show that when the armature winding is manufactured by adopting the flat cable, the conductors of the windings of all phases are made into a belt shape and are fully paved on the surface of the armature, so that the performance of the motor cannot be optimized, and the winding is inconvenient to pave and manufacture. The optimized calculation shows that when the ratio of the width a to the height b of the conductor of the flat cable is between 2 and 5, the harmonic content of the magnetic field generated by the conductor is small, the fundamental wave value of the magnetic induction intensity is maximum, and therefore the ratio of the width a to the height b of the conductor in the flat cable is in the range of 2-5.
The flat cable is manufactured by adopting the multi-core small-section conductor, so that the skin-collecting effect generated when the large-section conductor passes through alternating current can be reduced, and the resistance loss of the stator is effectively reduced. On the other hand, the cable made of the small-section conductor is softer, and the process difficulty in winding the armature winding can be reduced.
The cable conductor material of the long primary armature winding 11 is aluminum, but other conductor materials may be used. The arrangement of the windings is a single layer wave winding as shown in fig. 2. In this embodiment, the number q of slots per pole and phase is 1, and q may have other values, for example, q is 2.
The permanent magnet pole of this embodiment is shown in fig. 3. The permanent magnet magnetic pole is a short rotor, and adopts a structure of a Halbach permanent magnet array, and the embodiment adopts a Halbach array with 8 modules per period, that is, the number n of magnetic blocks of each pole pitch τ is 4. According to the constitution principle of Halbach array, the magnetizing angles of adjacent magnetic blocks in the array are changed by 45 degrees in sequence.
As shown in fig. 3, the permanent magnet array is secured using an aluminum sleeve 32, the aluminum sleeve 32 being shown in fig. 4. As shown in FIG. 3, three magnetic blocks 31 with magnetization directions of 45 °, 0 ° and-45 ° can be fixed in the same sleeve cavity 34, and another magnetic block 31 with magnetization direction of 90 ° can be fixed in another sleeve cavity 34. The other magnetic blocks are fixed in the same way.
In the Halbach permanent magnet array with the non-equal-height structure, the height of the magnet blocks magnetized along the oblique line direction is larger than the height of the magnet blocks magnetized along the transverse direction and the vertical direction. The inner cavities of the magnetic block fixing aluminum sleeves 32 are the same in height, and the vacant parts of the inner cavities of the sleeves filled with the magnetic blocks with lower heights are filled with filling blocks 33 made of non-magnetic materials.
The magnetic block 31 is enclosed in the sleeve cavity 34 by the baffle made of non-magnetic material at the two ends of the sleeve 32.
Compared with the motor in the prior art, the embodiment of the invention is improved in three aspects:
the improvement is as follows: the three-phase winding of the long stator adopts a flat double-core round conductor cable to replace a single-core round conductor cable of the motor in the prior art.
The prior art motor is shown in fig. 5, the armature winding 11 adopts a single core round cable made of a single core round conductor 13, and as shown in fig. 8, the outer part of the single core round cable made of the single core round conductor 13 is an insulating layer 14. The armature windings 11 are placed in the slots of the long stator winding fixture 12.
Fig. 11 is a comparison schematic diagram of cables of a long stator armature winding, wherein a single-core round conductor cable of a motor in the prior art is arranged on the left side of fig. 11, a flat double-core round conductor cable of the motor in the invention is arranged on the right side of the motor in the prior art, the conductor areas of the two cables are the same, and the thickness of the insulating layer 14 is the same. Because of the coreless core, the magnetic induction B of the magnetic field generated by the permanent magnet is rapidly attenuated along with the increase of the length of the air gap. As can be seen from FIG. 11, when the mechanical air gap H is the same, the single-core round cable made of the single-core round conductor 13 is adopted, and the distance from the lower surface of the conductor to the lower pole surface of the permanent magnet is H1(ii) a And the distance between the lower surface of the conductor and the lower pole surface of the permanent magnet is reduced to be H2. As can be seen from fig. 18, the magnetic induction density at the lower part of the circular cable conductor of the prior art motor is 0.3014T. The magnetic induction intensity of the lower part of the flat cable double-core conductor is 0.3310T, the magnetic field is improved by about 10 percent, and the thrust weight ratio can be correspondingly improved. Therefore, the flat double-core cable is adopted, so that the armature conductor arrangement is more planar, the electromagnetic air gap is reduced, the air gap magnetic induction intensity B at the conductor is higher, and the thrust force and the thrust weight ratio of the motor can be improved.
The results of calculating the air gap magnetic field and the thrust generated by the single-core round conductor cable and the flat double-core cable by using the finite element method are shown in fig. 12 and 13. Fig. 12 shows that, under the same conductor area, the amplitudes of the air gap magnetic induction B generated by the flat twin-core cable and the single-core round conductor cable are 0.016T and 0.014T, respectively, and the fundamental wave amplitude of the air gap magnetic induction B is 0.013T and 0.012T, respectively, that is, by using the flat twin-core cable, the amplitude of the air gap magnetic induction B generated by the conductor is improved by 14%, and the improvement effect of the air gap magnetic induction B is obvious. In the permanent magnet synchronous motor, a no-load magnetic field generated by a permanent magnet and an armature reaction magnetic field generated by an armature conductor are subjected to vector synthesis to form an air gap synthetic magnetic field, and the two magnetic fields are increased, which means that the synthetic magnetic field is improved, so that the thrust density is improved.
Fig. 13 is a thrust calculation for a single core, prior art, flat twin core cable long stator winding motor of the present invention. The comparison shows that under the condition that the structural size of the permanent magnet is the same as the conductor area of the cable, the flat double-core cable is adopted to improve the thrust of the motor by 300N, the thrust density of the motor is improved by 4.72%, and the utilization rate of the permanent magnet is improved.
The second improvement is that: the Halbach permanent magnet array adopts a new installation scheme
As shown in fig. 6, the magnet 31 in the permanent magnet Halbach array structure of the motor in the prior art is fixed by using an aluminum sleeve 32, wherein an arrow represents a magnetizing direction of the permanent magnet, and the sleeve structure is shown in fig. 7. In order to enhance the air gap magnetic field, the invention proposes a new magnetic block assembly structure, as shown in fig. 3. Namely, three magnetic blocks 31 magnetized in the similar magnetizing directions of one polar distance tau, such as the directions of 45 degrees, 0 degrees and-45 degrees, are placed in the same sleeve cavity 34 to be fixed, another magnetic block 31 magnetized in the 90 degrees magnetizing direction is placed in another sleeve cavity 34 to be fixed, and the rest magnetic blocks are installed and fixed in the same way. Under the same polar distance, the use amount of permanent magnet materials can be increased by adopting the mounting method, the air gap magnetic field is improved, and the thrust density of the motor is improved. And the three magnetic blocks with similar magnetization directions are placed in the same sleeve cavity 34, so that the installation difficulty of the magnetic block 31 is reduced, and the three pieces of magnetic steel are mutually attracted essentially.
Fig. 14 shows a comparison of the thrust force calculation results for the permanent magnet array mounting of the present invention as shown in fig. 3 and the permanent magnet array mounting of the prior art as shown in fig. 6. Under the condition of adopting a flat double-core cable and equal-height permanent magnets, the thrust of the motor can reach 6.97kN, and is improved by about 600N, namely 9.43 percent compared with the thrust of 6.36kN of the motor in the prior art shown in figure 5.
The improvement is that: by using unequal-height permanent magnets
In order to further improve the thrust of the motor, the invention adopts an unequal height Halbach permanent magnet array as shown in figures 3 and 16. When the permanent magnet 31 is fixed by the aluminum sleeve 32, the magnet 31 with a lower height is placed in the sleeve cavity 34, a vacant part appears in the sleeve cavity, and the vacant part is filled by the filling block 33 made of non-magnetic conductive material, so that the magnet 31 is fixed firmly, as shown in fig. 3.
Simulation calculation shows that increasing the height of the obliquely magnetized permanent magnet can increase the fundamental wave magnetic induction intensity of the air gap and reduce the harmonic content in the air gap magnetic induction intensity. When the height h is 46mm, the unequal thickness height d is increased, and the waveform of the thrust of the motor, which is calculated by the finite element method and varies with d, is shown in fig. 16. The results of fig. 16 show that the average thrust of the motor can be increased by 50N for every 1mm increase in the height of the obliquely magnetized permanent magnet. If the thickness is increased by 4mm, the thrust of the motor can be increased to 7.15kN, namely 12.42%.
Therefore, after three improvement technologies are adopted, the thrust of the motor is improved by 12.42%, the self weight of the permanent magnet pole is basically unchanged, and the thrust weight ratio is also improved by 12.42%. The invention has good technical improvement effect.
Example 2
In order to reduce the difficulty of the manufacturing process of the long stator armature winding 11 of the motor, the long stator winding 11 in embodiment 2 of the present invention adopts a flat arrangement, that is, the flat cable shown in fig. 9 or fig. 10 is used to manufacture the armature winding 11; however, the permanent magnet Halbach array still adopts the prior art, i.e. the permanent magnets are equal in height, and only one unit magnet 32 is placed in each sleeve cavity 34, as shown in fig. 6. When a Halbach array with 8 modules in one cycle is used, one sleeve contains 4 sleeve cavities. The simulation calculation result shows that the thrust of the motor can be improved by 3.33% by adopting the improved scheme.
Example 3
The long stator armature winding 11 of embodiment 3 of the invention adopts a flat arrangement, namely the flat cable of fig. 9 or fig. 10 is adopted to manufacture the armature winding 11; the permanent magnet Halbach array still adopts equal-height permanent magnets, but the fixing mode of the magnetic block 31 adopts the second improvement of the invention, and adopts an aluminum sleeve 32 structure as shown in figure 4; the three magnetization directions are close: if the magnetic blocks 31 along the magnetizing directions of 45 degrees, 0 degrees and-45 degrees are placed into one sleeve cavity 34 to be fixed, the other magnetic block 31 along the magnetizing direction of 90 degrees is placed into the other sleeve cavity 34 to be fixed, and the rest magnetic blocks are fixed in the same way.
Claims (7)
1. A coreless long-stator permanent magnet linear synchronous motor comprises a long primary (1), an air gap (2) and a short secondary (3), and is characterized in that: the three-phase or multi-phase armature winding (11) of the long primary (1) is placed in a winding fixing device (12) to form the long primary (1) of the motor; the winding fixing device (12) is made of non-magnetic conductive and non-electric conductive materials; the short secondary (3) is a permanent magnetic pole and adopts a Halbach permanent magnetic array structure; the magnetic blocks (31) in the permanent magnet array are fixed by a sleeve (32); the permanent magnet is a short rotor; an air gap (2) of the motor is arranged between the long stator and the short rotor; the permanent magnet linear synchronous motor is of a coreless structure.
2. The coreless long stator permanent magnet linear synchronous motor of claim 1, wherein: the long primary armature winding (11) is three-phase or multi-phase and is arranged in a flattened mode, and the armature conductors are arranged on the surface of the armature in a single-layer wave winding mode.
3. The coreless long stator permanent magnet linear synchronous motor of claim 2, wherein: the long primary armature winding (11) is made of flat cables; the conductor of the cable is a flat single-core conductor (15), a two-core round conductor (16) or a multi-core round conductor which is arranged in a flat mode, and an insulating layer (14) is arranged outside the conductor.
4. A coreless long stator permanent magnet linear synchronous motor according to claim 3, wherein: the ratio range of the width a to the height b of the flat cable conductor is 2-5.
5. The coreless long stator permanent magnet linear synchronous motor of claim 1, wherein: in the Halbach permanent magnet array with the non-equal-height structure, the height of the magnetic blocks (31) magnetized along the oblique line direction is greater than the height of the magnetic blocks (31) magnetized along the transverse direction and the vertical direction.
6. The coreless long stator permanent magnet linear synchronous motor of claim 5, wherein: the magnetic block (31) is fixed by a sleeve (32), and the sleeve (32) is made of a non-magnetic-conductive material; several magnetic blocks (31) with similar or same magnetizing directions are placed in the same sleeve (32) for fixation, and the two ends of the sleeve are closed by baffle plates made of non-magnetic materials.
7. The coreless long stator permanent magnet linear synchronous motor of claim 6, wherein: the heights of the inner cavities of the sleeves (32) are the same, and the vacant parts of the sleeves provided with the magnetic blocks (31) with lower heights are filled with filling blocks (33) made of non-magnetic materials.
Priority Applications (1)
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112735731A (en) * | 2020-12-11 | 2021-04-30 | 山东省科学院自动化研究所 | Mounting sleeve structure and mounting method for Halbach permanent magnet array with irregular cross section and unequal thickness |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011067030A (en) * | 2009-09-18 | 2011-03-31 | Yaskawa Electric Corp | Field of linear motor, and linear motor with the same |
| CN207677614U (en) * | 2017-12-22 | 2018-07-31 | 西安交通大学 | A kind of magnetic-suspension linear motor |
| CN108649769A (en) * | 2018-05-28 | 2018-10-12 | 浙江大学 | A kind of coreless permanent magnet linear synchronous motor based on Double Layer Winding structure |
| CN208707510U (en) * | 2018-08-10 | 2019-04-05 | 北京九州动脉隧道技术有限公司 | A kind of structure of the linear motion actuator and magnetic suspension train |
| CN109698600A (en) * | 2018-12-10 | 2019-04-30 | 中国科学院电工研究所 | A kind of linear motor with auxiliary weak magnetic structure |
| WO2019121037A1 (en) * | 2017-12-20 | 2019-06-27 | Physik Instrumente (Pi) Gmbh & Co. Kg | Electric motor |
| CN110545023A (en) * | 2019-08-21 | 2019-12-06 | 同济大学 | Segmented coreless long-stator permanent magnet linear synchronous motor for rail transit |
-
2020
- 2020-03-17 CN CN202010187518.6A patent/CN111327174B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011067030A (en) * | 2009-09-18 | 2011-03-31 | Yaskawa Electric Corp | Field of linear motor, and linear motor with the same |
| WO2019121037A1 (en) * | 2017-12-20 | 2019-06-27 | Physik Instrumente (Pi) Gmbh & Co. Kg | Electric motor |
| CN207677614U (en) * | 2017-12-22 | 2018-07-31 | 西安交通大学 | A kind of magnetic-suspension linear motor |
| CN108649769A (en) * | 2018-05-28 | 2018-10-12 | 浙江大学 | A kind of coreless permanent magnet linear synchronous motor based on Double Layer Winding structure |
| CN208707510U (en) * | 2018-08-10 | 2019-04-05 | 北京九州动脉隧道技术有限公司 | A kind of structure of the linear motion actuator and magnetic suspension train |
| CN109698600A (en) * | 2018-12-10 | 2019-04-30 | 中国科学院电工研究所 | A kind of linear motor with auxiliary weak magnetic structure |
| CN110545023A (en) * | 2019-08-21 | 2019-12-06 | 同济大学 | Segmented coreless long-stator permanent magnet linear synchronous motor for rail transit |
Non-Patent Citations (2)
| Title |
|---|
| KE WANG 等: "Development of ironless Halbach permanent magnet linear synchronous motor for traction of a novel maglev vehicle", 《IEEE》 * |
| 杜玉梅，史黎明，金能强: "《混合励磁磁浮系统磁力分析》", 《研究与实验》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112735731A (en) * | 2020-12-11 | 2021-04-30 | 山东省科学院自动化研究所 | Mounting sleeve structure and mounting method for Halbach permanent magnet array with irregular cross section and unequal thickness |
| CN112735731B (en) * | 2020-12-11 | 2023-09-08 | 山东省科学院自动化研究所 | Method for mounting Halbach permanent magnet array with irregular cross section and unequal thickness |
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