A kind of low-loss low speed permanent magnet synchronous motor
Technical field
The present invention relates to a kind of motor, particularly a kind of low-loss low speed permanent magnet synchronous motor.
Background technology
Magneto has advantages such as life-span length, easy maintenance because of it, along with developing rapidly of electronic technology is applied in more and more widely, for example: technical fields such as wind power generation, hybrid vehicle, aviation, electronic equipment, mining.
Existing low-speed permanent-magnet synchronous generator or motor mainly are made up of stator, rotor, bearing and casing etc.Stator generally becomes stator core by the silicon steel sheet closed assembly, is stator winding in its core slots.Wherein stator winding generally all adopts distributed winding, and its existence long problem of complicacy, manufacturing cycle that rolls off the production line is because the coil-end minister causes stator copper loss high.In order to solve the distributed winding complicated problems that rolls off the production line; Also have in the prior art and adopt the magneto of concentrating winding configuration; For example: CN101227108A discloses a kind of polyphase synchronous machine of concentrated winding construction, and its armature winding is winding in the heterogeneous symmetric set.Yet, when this synchronous machine when the number of teeth more for a long time, the opposite or every coil winding-direction on m-1 tooth of the coil winding-direction on two adjacent core tooth of every phase is opposite, makes troubles to rule and wiring so undoubtedly.And the cogging torque height is the existing ubiquitous problem of low speed permanent magnet synchronous motor, particularly can have a strong impact on the motor runnability for slowspeed machine.
The rotor of existing low speed permanent magnet synchronous motor comprises rotor block and magnet steel, magnet steel surface-type, built-in and Lundell be installed.For rotor; If adopt the surface-type magnetic structure; Generally also need permanent magnet is carried out colligation or adds a non-permeability alloys steel sheath in the permanent magnet outside, the former used carbon fiber colligation material is the non-conductor of heat, is unfavorable for the rotor heat radiation; The used sheath of the latter is an electric conductor, can produce eddy current loss.In addition, the design of this colligation or sheath makes the effective air gap of motor increase, the increase of main magnetic circuit and magnetic leakage factor, thereby the exerting oneself and then can reduce efficiency of motor of utilance and motor of having reduced permanent magnetic material.Wherein permanent magnet generally is overall structure, and its eddy current loss is high.There are the problems referred to above in rotor and stator just because of existing permagnetic synchronous motor, not only influence the temperature rise that efficiency of motor is also aggravated motor, therefore in order to reduce electric machine temperature rise, the demagnetization of unlikely permanent magnet, to influence motor performance, need the configuration pressure cooling system.
Therefore, a kind ofly can reduce copper loss, simplify mounting process, reduce eddy current loss and then reduce the temperature rise motor, the permagnetic synchronous motor of raising the efficiency becomes the target that those skilled in the art pursue.
Summary of the invention
The objective of the invention is to solve existing permanent-magnetic synchronous motor stator copper loss height, big, the wiring complicated technology problem of cogging torque.
Another object of the present invention is to solve the inconvenient problem of stator winding rule of existing permagnetic synchronous motor.
Another purpose of the present invention is to solve the uneven high problem of the high loss of high order harmonic component electromotive force that causes of air gap between existing permanent-magnetic synchronous motor rotor permanent magnet and the stator.
Another purpose of the present invention is to solve existing permanent-magnetic synchronous motor rotor permanent magnet to have the high problem of eddy current loss.
The technical scheme that the present invention taked is: a kind of multipole permagnetic synchronous motor of low rotor loss, and it comprises rotor and stator, said stator comprises stator core and stator winding; It is characterized in that said motor utmost point groove mix proportion is 5: 6; The number of teeth of said stator core is S=2nm, and m is the number of phases, and n is the even number more than or equal to 2; Said stator winding is a polyphase windings, and every phase winding is made up of a coil unit at least; Said coil unit be by on adjacent two teeth around constituting to identical monodentate half winding; And the end of monodentate half winding on two teeth of said coil unit links to each other, and the lead-in wire of monodentate half winding on the two adjacent teeth of per two adjacent windings unit is all output or is all input.
As preferably, m adjacent in said stator winding coil unit constitutes a polyphase windings unit, n the polyphase windings unit of nm coil unit formation on the said 2nm tooth; A said polyphase windings unit or two, two above polyphase windings cell string, parallel connection or series-parallel connections constitute independently polyphase windings of at least one cover.
As preferably, said n polyphase windings unit constitutes n and overlaps independently polyphase windings, wherein n/2 cover even number polyphase windings parallel connection, the parallel connection of n/2 cover odd number polyphase windings; The perhaps polyphase windings parallel connection of 180 degree symmetric positions.
As preferably; Said i adjacent polyphase windings units in series constitutes one and overlaps independently polyphase windings; N polyphase windings unit constitutes n/i and overlaps independently polyphase windings, the wherein polyphase windings parallel connection of n/2i cover even number, the parallel connection of n/2i cover odd number polyphase windings, and i is the natural number of aliquot n.
As preferably, said n polyphase windings units in series constitutes one and overlaps independently polyphase windings.
In order to improve the rule wiring of stator winding, improve effect, the space width ratio of said stator core is 1, promptly groove width is identical with the facewidth.
Distribute in order to be beneficial to air-gap field, said rotor comprises permanent magnet, pole shoe and rotor block; Said pole shoe is circumferentially evenly arow setting at interval along the rotor block surface, and arow is provided with permanent magnet between the said adjacent columns pole shoe, and the two sides of said pole shoe are respectively equipped with the protuberance that is used to compress the both sides permanent magnet; Said permanent magnet is fixed on the said rotor block surface through the adjacent pole shoe in its both sides.
As preferably, the fixing of said pole shoe preferably established an installing hole and a fixing hole in pole shoe, and said installing hole is located at the center of said pole shoe with being parallel to rotor axial, and said fixing hole vertically connects setting towards said installing hole under said pole shoe.Can avoid hold-down screw exposed outside like this, particularly make the thickness of periphery of pole shoe even, make air gap even, help Distribution of Magnetic Field.
For the pole shoe convenient fixing, be preferably in and be provided with one in the installing hole of said pole shoe and extend axially the pole shoe fixed lever that connects axial pole shoe, said pole shoe fixed lever is fixed on said pole shoe on the said rotor block through screw.
Simultaneously, for permanent magnet fixation in the axial direction, as preferably, the outer face of permanent magnet is provided with the fixedly dististyle that is used for the axial restraint permanent magnet in said rotor block end, and said fixedly dististyle is fixed on the end of said pole shoe fixed lever; The said permanent magnet fixedly position of the corresponding pole shoe installing hole in upper end of dististyle has a v-shaped openings.
As preferably, the protuberance that said pole shoe is used for fixing permanent magnet is located at the two ends of the outer peripheral face of pole shoe.Thereby between adjacent pole shoe, form a mounting groove, permanent magnet can be inserted wherein easily.What wherein should explain is: the outer peripheral face of pole shoe of the present invention is meant: pole shoe is installed to the periphery that its outer surface of back forms on the rotor block.
In order further to improve DISTRIBUTION OF MAGNETIC FIELD, as preferably, the outer peripheral face of said pole shoe is outwards outstanding curved surface shape.
In order further to reduce eddy current loss, best said permanent magnet is the bonding formation of two-layer, two-layer above magnetic material.
The present invention is owing to adopt technique scheme, and motor utmost point groove mix proportion is 5: 6, can reduce by 6 subharmonic in the cogging torque, reduces cogging torque thus, improves the motor runnability; The stator winding of motor is symmetrical monodentate half winding, can reduce stator copper loss effectively, through changing the wiring direction of adjacent winding element; Make each monodentate half winding around to identical, when making, can coil unit of a coiling; And disposable being embedded on two teeth groove, reduced the wiring work between two and half windings, simplified mounting process; Therefore, the present invention compares with existing concentrated winding, makes wiring simpler, succinct; Improve the assembly efficiency of motor, shortened the making duration greatly, reduced production cost.Simultaneously; Each coil unit of the present invention is to be made up of half winding on two adjacent two teeth; A coil turn with respect to the full winding of monodentate reduces half, thereby reduces half with respect to the heat that winding on each tooth of the full winding of monodentate produces, and epitrochanterian eddy current loss also reduces greatly; Thus, improve efficiency of motor.
Further, the present invention has taken all factors into consideration cogging torque and the two aspect factors that make things convenient for rule of reducing, and the space width ratio of selection motor stator is 1, and rule is more prone to, and reaches the best optimization design.
Further, rotor according to the invention adopts the layout fixed structure of specific permanent magnet, and promptly the permanent magnet compartment of terrain is located at the surface of rotor block, and fixes through pole shoe, can improve Distribution of Magnetic Field thus, reduces eddy current loss.Simultaneously, owing to adopt monodentate half winding and permanent magnet pole shoe arrangement, compare with traditional permanent magnet surfaces formula, built-in and Lundell mounting means; Not only improve the magnet installation effectiveness, also improved the reliability of motor, and reduced the effective air gap between rotor; And make air gap even; Can effectively weaken the high order harmonic component electromotive force, suppress high order harmonic component, increase exerting oneself and corresponding raising efficiency of motor of motor.
Further, the present invention is divided into sandwich construction with permanent magnet, can further reduce eddy current loss, improves electric efficiency.
Further, the present invention is arcuation, makes that its thickness is more even the peripheral shape of pole shoe, effectively weakens the high order harmonic component electromotive force, helps improving the induced electromotive force waveform.
Stator winding of the present invention is selected the structure of monodentate half winding for use, and motor utmost point groove mix proportion is 5: 6, and cooperates the layout fixed structure of specific permanent magnet; And the structure of pole shoe, make the loss of rotor portion reduce by 50% with respect to full winding mode, cause the rotor loss of the 3MW generator that adopts technical scheme of the present invention to have only 17 kilowatts; Efficiency of motor is up to 97%; Also reduce electric machine temperature rise when reducing the wastage, need not to establish in addition forced cooling device, only depend on the natural draft cooling to get final product.
Description of drawings
Fig. 1 is the structural representation of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 2 is the rotor end-face partial schematic diagram of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 3 is the rotor local vertical view of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 4 is the structural representation of the epitrochanterian pole shoe of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 5 is the stator winding sketch map of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 6 is the stator winding sketch map of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 7 is the stator winding sketch map of the low-loss low speed permanent magnet synchronous motor of the present invention;
Fig. 8 is the stator winding sketch map of the low-loss low speed permanent magnet synchronous motor of the present invention.
Embodiment
Embodiment one, referring to Fig. 1, showed low-loss low speed permanent magnet synchronous motor of the present invention among the figure; It comprises rotor 100 and stator 200; Said stator 200 comprises casing 203, stator core 201 and stator winding 202, and rotor 100 comprises rotor block 101, rotating shaft 102, and said motor utmost point groove mix proportion is 5: 6; Wherein have in the stator core 201 48 teeth 2001,2002 ... 2048 (Fig. 2 shows), and rotor surface has 40 pairs of permanent magnets 112; Stator structure comprises stator core 201 and stator winding 202, in the present embodiment specifically referring to Fig. 2; Number of motor phases m is 3, has in the stator core 201 to be used for the nested tooth of coil 2001,2002,2003 ..., 2047,2048, the number of teeth is 48; S=2nm, n are 8; Every phase winding is made up of a coil unit, among the present invention, coil unit a1 be by on adjacent two teeth (for example: tooth 2001, tooth 2002) around constituting to identical monodentate half winding 1 and monodentate half winding 2; Coil unit b1 is made up of half winding 3 and half winding 4; Coil unit c8 is made up of half winding 47 and 48; Wherein each coil unit in two monodentates, half winding 1 and the end of half winding 2 be connected as a single entity, both are that a coiling forms when coiling, promptly each coil unit by two coilings form, in the same way, the terminal monodentate half winding tooth that links to each other constitutes; Thus; Have 24 coil units (a1, b1, c1, a2, b2, c2 on 48 each and every one teeth ..., a8, b8, c8).The lead-in wire of the monodentate half coil on the two adjacent teeth of per two adjacent windings unit is all input or is all output; Two and half windings 1,2 like coil unit a1; If 1 is input; 2 are output (connecing asterism), and the half adjacent winding 3 of then adjacent with it coil unit b1 is output) (connecing asterism), half winding 48 of adjacent with it coil unit a8 then is input (connecing lead end).Other coil units and the like.Each coil unit constitutes the phase in three phase windings, and every 3 adjacent coil units constitute a three-phase winding element; 24 coil units on 48 teeth constitute 8 three-phase winding elements (a1, b1, c1); (a2, b2, c2); (a8, b8, c8); A polyphase windings unit, perhaps two, two above polyphase windings cell string, parallel connection or series-parallel connections constitute independently polyphase windings of at least one cover.Concrete connecting mode in the present embodiment sees also Fig. 3.The space width ratio of stator core 201 is 1, and promptly the facewidth and groove width equate, is beneficial to coil and installs.
Referring to Fig. 3, provided a kind of concrete connected mode of 8 three-phase winding elements in the present embodiment, with 8 the three-phase winding elements (a1, b1, c1) among Fig. 1; (a2, b2, c2); (a8, b8, c8) constitutes independently three phase windings of a cover respectively, is: (A1, B1, C1), (A2, B2, C2); (A3, B3, C3); (A4, B4, C4) ... (A8, B8, C8).These 8 three phase windings independently, all parallel connection is used.Also wherein even number parallel connection, odd number are parallelly connected, i.e. three phase windings (A1, B1, C1), (A3, B3, C3), (A5, B5, C5), (A7, B7, C7) parallel connection; (A2, B2, C2); (A4, B4, C4) ... (A8, B8, C8) parallel connection is used respectively.The connected mode of present embodiment can make different independent three-phase systems work independently on the one hand, and when working simultaneously, wherein independently three phase windings inefficacy of a cover does not influence the continuation operation of complete machine.Adopt symmetric mode to connect and make shaft strength balanced, motor operates steadily.
Referring to Fig. 4, Fig. 4 is the partial schematic diagram of rotor, is provided with permanent magnet 112 and pole shoe 113 on rotor 100 surfaces.Referring to Fig. 4,5; Pole shoe 113 is circumferentially evenly arow settings at interval along rotor block 101 surface, referring to Fig. 6, are respectively equipped with outward extending protuberance 1131 in the both sides of the outer peripheral face of pole shoe 113; Thereby between adjacent pole shoe 113, form a passage, be used for inserting and fixed permanent magnet 112.Thus, permanent magnet 112 arows are fixed on the surface of rotor block 101.
Referring to Fig. 6; Wherein pole shoe 113 comprises an installing hole 1132 and a fixing hole 1133; Said installing hole 1132 is along being parallel to the center that rotor axial is located at pole shoe 113 with connecting; See from end face or cross section, the installing hole 1132 of pole shoe 113 be shaped as arch, said fixing hole 1133 is provided with towards said installing hole 1132 vertical perforations from the following of said pole shoe 113.In the present embodiment, fixing hole 1133 is the strip through hole that axially connects, and is more convenient for installing.Referring to Fig. 4,5, in the installing hole 1132 of said pole shoe 113, be provided with one and extend axially the pole shoe fixed lever 114 that connects axial pole shoe 113, pole shoe fixed lever 114 is fixed on said pole shoe 113 on the said rotor block 101 through screw 117.The outer face of permanent magnet 112 is provided with fixedly dististyle 115 in the end of rotor block 101; Be used for axial restraint permanent magnet 112; The both ends of pole shoe fixed lever 114 have the upwards stiff end 1145 of 90 ° of bendings, and fixedly dististyle 115 is fixed on the stiff end 1145 of pole shoe fixed lever 114; Fixedly the position of the corresponding pole shoe installing hole 1132 in the upper end of dististyle 115 has a v-shaped openings.The present invention is designed to through-hole form with the installing hole 1132 of pole shoe 113, and fixedly dististyle 115 has opening in the position of installing hole 1132, thereby is beneficial to ventilation and heat.
In order to prevent leakage field, between pole shoe 113, permanent magnet 112 and said rotor block 101, be provided with pole shoe insulator 116.
In order further to be beneficial to DISTRIBUTION OF MAGNETIC FIELD, the outer peripheral face of pole shoe 113 is outwards outstanding curved surface shape,
In the present embodiment, permanent magnet 112 is four layers of bonding formation of magnetic material, can reduce eddy current loss effectively thus, raises the efficiency.
The present invention is because motor utmost point groove mix proportion is 5: 6, and stator winding 202 adopts the half coil form, and permanent magnet 112 is fixing through pole shoe 113; Thereby can reduce stator winding caused loss in rotor greatly; And through pole shoe 113 can make DISTRIBUTION OF MAGNETIC FIELD evenly, reduce eddy current loss, can suppress high order harmonic component effectively, and the ad hoc structure of pole shoe 113 makes the rotor ventilation radiating effect better; Reduce the air gap between rotor and the stator simultaneously, improved electric efficiency.So motor of the present invention has the advantage that loss is low, temperature rise is low, efficient is high, need not to establish in addition cooling device.
Embodiment two; Referring to Fig. 7; Provided the different stator winding connected mode of showing among the Fig. 3 with embodiment one among the figure: with the first group of three-phase winding element (a1, b1, c1) in 8 three-phase winding elements and second group of three-phase winding element (a2, b2, c2) series connection, the 3rd group of three-phase winding element (a3, b3, c3) connected the 5th group and the 6th group of series connection with the 4th group of three-phase winding element (a4, b4, c4); The 7th group and the 8th group of series connection so constitute independently three phase windings of quadruplet.In conjunction with Fig. 2 and Fig. 7, with wherein first group be its connecting mode of example explanation.Clear in order to describe, with the left side one end of coil unit a1 be defined as head end, the right one end is defined as end, the adjacent end with a1 of coil unit b1 is that head end, the other end are terminal (following examples are identical) successively.The head end of coil unit a1 in the three-phase winding element (a1, b1, c1), the end of b1, the head end of c1 connect exit respectively, and the end of coil unit a1 connects the end of the coil unit a2 of three-phase winding element (a2, b2, c2); The head end of the head end line coil unit b2 of coil unit b1, the end of the terminal line coil unit c2 of coil unit c1 thus, constitutes independently three phase windings (A1, B1, C1), by that analogy, constitutes in addition three independently three phase windings (A2, B2, C2); (A3, B3, C3); (A4, B4, C4); 4 independently three phase windings can be parallel connection and use; Perhaps with three phase windings (A1, B1, C1) and three phase windings (A3, B3, C3) parallel connection, ((A4, B4, the C4) parallel connection of three phase windings (A2, B2, C2) and three phase windings.
Embodiment three; Referring to Fig. 8, provided among the figure with Fig. 3 of embodiment one and embodiment two Fig. 7 in the different stator winding connected mode of showing: with first, second, third and fourth group three-phase winding element (a1, b1, c1), (a2, b2, c2), (a3, b3, c3); (a4, b4, c4) polyphone is independently three phase windings (A1, B1, C1), with the 5th, six, seven, eight group of three-phase winding element (a5, b5, c5), (a6, b6, c6), (a7, b7, c7); (a8, b8, c8) polyphone is independently three phase windings (A2, B2, C2); (A1, B1, C1) is example with first three phase winding: the head end of the coil unit a1 in the three-phase winding element (a1, b1, c1), the end of b1, the head end of c1 connect exit respectively, and the end of a1 connects the end of the coil unit a2 of three-phase winding element (a2, b2, c2); The head end of the head end line coil unit b2 of coil unit b1, the end of the terminal line coil unit c2 of coil unit c1; The head end of the head end coil unit a3 of coil unit a2, the end of the terminal connecting coil unit b3 of coil unit b2, the head end of the head end connecting coil unit c3 of coil unit c2; The terminal connecting coil unit a4 of coil unit a3 is terminal; The head end of the head end connecting coil unit b4 of b3; The end of coil unit c3 connects the end of c4; The head end of the head end of coil unit a4, the end of b4, c4 connects asterism, constitutes independently three symmetrical monodentate half windings (A1, B1, C1) thus, and another independent three phase windings are identical with it.
Obviously, stator winding of the present invention is not limited to above-mentioned connected mode, can also all three-phase winding elements all be connected, and constitutes independently three phase windings.Can also change the number of teeth of motor stator, the number of pole-pairs of rotor, obtain more execution mode.It is 5: 6 that the present invention aims to provide a kind of motor utmost point groove mix proportion, and stator winding is monodentate half winding, and the space width ratio is 1, the multipole permagnetic synchronous motor of the low rotor loss through the pole shoe fixed permanent magnet.Those of ordinary skills understand, and under the situation of spirit that does not break away from claim and limited and scope, can make many modifications, variation or equivalence, all will fall within protection scope of the present invention.