Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
  • H02K21/02—Details
  • H02K21/04—Windings on magnets for additional excitation ; Windings and magnets for additional excitation
  • H02K21/042—Windings on magnets for additional excitation ; Windings and magnets for additional excitation with permanent magnets and field winding both rotating
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
  • H02K21/02—Details
  • H02K21/04—Windings on magnets for additional excitation ; Windings and magnets for additional excitation

Definitions

• the invention relates to a rotary double excitation electric machine allowing a modular flux reduction, that is to say a control of the power supplied by the machine not necessarily maximum.
• This rotary electrical machine can be an alternator or an alternator-starter for a motor vehicle.
• the invention finds applications in all fields requiring the generation of electricity and, in particular, in the automotive field for generating electricity to the on-board network of vehicles with thermal engine or hybrid vehicles.
• Single-phase or multi-phase alternators and alternator-starters of conventional motor vehicles include, as described for example in document EP-0515 259, a stator inside which rotates a claw rotor provided with an excitation winding. powered by brushes in contact with two slip rings provided on a projecting part of the rotor shaft. The brushes are connected to a voltage regulator controlling the voltage of the excitation winding.
• the electrical supply to the rotor excitation winding makes it possible to magnetize the rotor and create magnetic fluxes which pass around the strands of the armature winding housed in the notches of the magnetic structure body which the stator presents. These magnetic fluxes generate an induced current in the induced winding of the stator and therefore an electrical power in the machine.
• the power produced is zero when the electric current in the excitation winding is zero, but the power level that can provide such a machine is limited by its electromagnetic design.
• Rotating electrical machines make it possible to solve the problems of the techniques mentioned above.
• These machines described for example in document US-A-563605, comprise rotors comprising both permanent magnets and excitation coils or coils.
• the permanent magnets are said to be surface since they are installed circumferentially at the outer periphery of the rotor to produce a radial flux.
• Such rotors, installed on machines having high numbers of poles make it possible to increase the yields obtained with the preceding machines. They also make it possible to reduce, or even cancel, the magnetic flux produced by the magnets and, consequently, the power produced by the machine.
• the electric machine can supply the electric power only necessary for the on-board motor vehicle network.
• the current delivered is controlled, using switching means, at the level of the excitation windings.
• switching means make it possible to selectively reverse the direction of excitation of the windings in order to reduce or cancel the flux of the magnets.
• These switching means consist of a semiconductor switching bridge, called an H-bridge.
• Such an H-bridge has the disadvantage of being expensive.
• FIGS. 1a to 1b show an embodiment of a mixed rotor 200 described in document EP-A-0 942 510 and comprising at its outer periphery surface permanent magnets with radial flux.
• This rotor here of annular shape, comprises twelve poles 1 to 12, including three poles with permanent magnets 1, 5 and 9, three poles with windings or excitation coils 3, 7 and 11 and six poles with reluctance 2, 4, 6, 8, 10 and 12.
• the reluctance poles are the intermediate poles through which circulate the magnetic fluxes emitted by the magnets and / or the poles with excitation windings.
• These poles with excitation windings are each delimited by two notches in each of which is housed a wire, for example a copper wire, wound around the pole concerned for formation of the excitation winding with the interposition of an insulator.
• These salient poles here each have at their outer periphery an enlarged head for forming retaining shoulders for the associated excitation winding.
• the poles with permanent magnets are delimited circumferentially at each of their circumferential ends by a shallow empty notch.
• the poles with permanent magnets each comprise at least one circumferentially oblong-shaped housing for mounting a permanent magnet.
• the magnets are surface-mounted and are located in the vicinity of the external periphery of the rotor to produce a radial magnetic flux.
• the reluctance poles each advantageously have at their outer periphery a circumferential projection directed towards the pole with adjacent excitation winding to radially retain the excitation winding.
• Two reluctance poles are installed on either side of a permanent magnet pole, while an excitation winding pole is located between two consecutive reluctance poles.
• poles with excitation windings will be referred to below. after also wound poles and permanent magnet poles magnet poles.
• the wound poles When they are not excited or activated by the passage of an electric current, the wound poles react like reluctance poles, i.e. they have no effect on the direction of the magnetic flux emitted by permanent magnets.
• the magnetic polarities observed in the rotor are those noted in FIG. 1a, namely S (South) for the magnet poles and N (North) for the other poles.
• each magnet produces two magnetic fluxes F3 which are each divided into two magnetic fluxes F1 and F2 towards, on the one hand, the reluctance poles 2, 4, 6, 8, 10 and 12 and on the other hand, towards the wound poles 3 - 7 and 11 which are not excited and behave like reluctance poles.
• the rotary electrical machine comprises a polyphase stator provided with a body made of magnetic material, also called a carcass, provided with notches, preferably semi-closed at the internal periphery of the stator , which receive the strands of the armature windings that comprise the stator.
• notches are separated from each other by teeth, also called poles.
• the aforementioned flows F1 to F3 pass through the teeth of the stator, a small air gap existing between the stator and the rotor.
• the calibration is determined as a function of the magnets and, more precisely, of the size, type, number and location of the magnets in the machine.
• Calibration (called Ibase below) is the level of basic power that the machine can provide only with permanent magnets, that is to say when the windings are not energized. Such a machine can provide, for example, in alternator mode, a basic current of 45 amps.
• the total electric power supplied by the machine increases compared to the power supplied by the magnets alone. If the magnets provide alone, for example an intensity of 45 amperes, then the total intensity supplied by the machine will be for example 90 amperes.
• defluxing This characteristic which consists in being able to control the power supplied by the machine, is called defluxing.
• This defluxing can be controlled as a function of the speed of rotation of the rotor.
• the magnetic flux produced at the level of the rotor can either be reduced markedly, or be canceled completely, according to the values and direction of the currents supplied to the excitation windings of the rotor.
• These machines can therefore produce a power which can vary between a base power, produced by the magnets alone and a maximum power produced by the magnets and the coils.
• the power produced can vary between a zero or almost zero value and a maximum value, it is two values being located on either side of the base power produced by magnets alone.
• the choice of the number of magnets becomes an important criterion in order to be able to provide the basic power which the application needs, at the average speed of rotation of the desired machine, without injecting current. in the excitation coils in order to optimize the yield.
• the object of the invention is precisely to remedy, in a simple and economical manner, the problems described above.
• An object of the invention is to propose rotor structures with double excitation whose base power produced is modular.
• the rotor comprises poles with permanent magnets and poles with excitation windings, placed so as to produce a particular elementary pattern which can be reproduced several times on the rotor.
• the number of magnets and the number of excitation coils as well as their respective locations and the number of elementary patterns can be modified as a function of the desired base power in the machine.
• the invention relates to a rotary electrical machine comprising a rotor having a body made of magnetic material, a stator surrounding the rotor, the stator comprising at least one armature winding, housed in notches made in the magnetic body that presents the stator, and the rotor being provided with means for selectively establishing closed magnetic circuits passing around the armature winding, these means including:
• - permanent excitation magnets capable of establishing magnetic fluxes having, in the direction of movement of the rotor, components of opposite directions, and - excitation coils housed in notches of the rotor, adapted to be excited and to generate magnetic flux components opposing the magnetic fluxes generated in the magnets.
• the machine of the invention is characterized in that the number (Na) of permanent magnets and the number (Nb) of excitation coils as well as the arrangement of the coils and magnets with respect to each other form a pattern elementary, this elementary pattern being able to be repeated a number (Nme) of times, these numbers Na of magnets, Nb of coils and Nme of elementary patterns being modifiable as a function, on the one hand, of a desired basic intensity in the machine, this basic intensity being determined when the windings are not energized and, on the other hand, of a desired modulation intensity in the machine, this modulation intensity being determined when the windings are energized.
• Preferred, but not limiting, aspects of the machine according to the invention are as follows: - Na is greater than or equal to 1, Nb is greater than or equal to 1, Nme is greater than or equal to 1 and the torque of number Na, Nb is different from 1, 1.
• the Na magnets of the same elementary pattern are arranged to generate a radial magnetic flux.
• At least two consecutive magnets are separated by at least one reluctance pole.
• At least two consecutive wound poles are separated by at least one reluctance pole.
• At least one coiled pole and a magnet are separated by at least one reluctance pole.
• At least two consecutive elementary patterns Between at least two consecutive elementary patterns, a succession of at least a pair of North-South or South-North poles created by at least one magnet is inserted. - At least one magnet interposed between two consecutive elementary patterns is of different polarity from the at least one magnet belonging to at least one elementary pattern.
• the modulation intensity (Imod) is included in an interval between -Ib and + lb, where Ib is the maximum magnetic intensity provided by the Nb coils.
• FIG. 1a to 1b are schematic cross-sectional views of an example of a twelve-pole machine according to the prior art respectively in a state of non-excitation of the excitation windings and in a state of excitation of the windings.
• - Figure 2 is a schematic cross-sectional view of a first embodiment of a twelve-pole machine according to the invention.
• FIG. 3 is a view similar to Figure 2 for a second embodiment of a twelve-pole machine according to the invention.
• - Figure 4 schematically illustrates in developed form a variant embodiment of the invention of the rotor part of a machine according to FIG. 2.
• FIG. 5 schematically illustrates in developed form an alternative embodiment of the invention of the rotor part of a machine according to FIG. 3.
• N and S are used, as in Figures 1a and 1b, to designate a North Pole and a South Pole respectively.
• the invention relates to a rotating double excitation electric machine, in which it is possible to modulate the base power emitted by the magnets alone as well as the defluxing.
• the basic power is supplied by the permanent magnets alone, that is to say when the excitation coils or excitation coils are not electrically supplied.
• This basic power corresponds to the calibration of the machine. It depends on the number of magnets in the machine and also on the positioning of the magnets in the rotor (radial, orthoradial, etc.).
• the invention proposes to modulate the base power by playing on the number Na of magnets, the number Nb of windings and a number Nme of elementary patterns.
• Na is greater than or equal to 1
• Nb is greater than or equal to 1
• Nme is greater than or equal to 1
• the pair of numbers Na, Nb is other than 1.1.
• An elementary pattern is a set of magnets and coils associated with a particular order and distributed over all or part of the contour of the rotor.
• An elementary pattern can be repetitive, that is to say it can be associated with one or more other identical elementary patterns.
• An elementary pattern can also be associated with one or more other different elementary patterns.
• the base power varies depending on the number of Na magnets in each elementary pattern and of the number Nme of elementary patterns on the contour of the rotor.
• the modulation power called Imod, depends on the number of windings Nb and on the number Nme of elementary patterns present on the contour of the rotor.
• Imod depends on the number of windings Nb and on the number Nme of elementary patterns present on the contour of the rotor.
• the configuration of the rotor will be such that the negative or positive defluxing produced by the wound poles, or poles with excitation windings, will be partial or total.
• FIG. 2 shows an example of a rotor according to the invention.
• This rotor has twelve poles distributed in two elementary patterns, each elementary pattern comprising two magnet poles and a wound pole.
• the rotation shaft 15 is shown, of which the rotor is integral, having for this purpose a body made of magnetic material integral with this shaft.
• the elementary patterns me1 and me2 comprise a first permanent magnet pole 30, 24 followed by a first reluctance pole 31, 25, a second magnet pole 20, 26, a second reluctance pole 21, 27 d 'a wound pole 22, 28 and finally a third reluctance pole 23, 29.
• two magnets are separated by at least one reluctance pole.
• a wound pole and a magnet pole are separated by at least one reluctance pole.
• the first and second magnet poles are here identical and similar to the poles 1 of FIG. 1 a.
• the second and third reluctance poles are similar to poles 2 and 4 of Figure 1a so that the wound pole is similar to that of this Figure 1a.
• the first reluctance pole is delimited at its outer periphery circumferentially by two shallow empty notches of the type of those of FIG. 1a.
• the magnets are therefore oriented so as to provide here a north radial polarity.
• the polarities of the elementary pattern are: NSNSSS.
• the windings are positively excited, the following succession of magnetic poles is obtained: NSNSNS, the coiled pole passing from a South polarity to a North polarity.
• the defluxing is positive and the power supplied is greater than the base power supplied by the magnets alone.
• the two patterns me1 and me2 are identical, placed circumferentially one after the other.
• FIG. 2 represents a first embodiment of the invention in negative flux-reduction mode and in which the coils are activated by an excitation current flowing in the opposite direction.
• the wound poles remain South poles and generate a defluxing magnetic flux Fd which cancels part of the flux (Fs) emitted by the magnets closest to this wound pole.
• Such a machine will not carry out a total negative defluxing via the excitation coils and will advantageously find applications in which one very often uses about 2/3 of the maximum power of the machine corresponding to an almost zero excitation for this power. .
• FIG. 3 shows a second example of a rotor according to the invention.
• This rotor has twelve poles distributed in two identical elementary patterns me3 and me4, each comprising a magnet pole and two wound poles.
• the elementary patterns me3 and me4 first include a magnet pole 40, 46 followed by a first reluctance pole 41, 47, then a first wound pole 42, 48, a second reluctant pole 43, 49, a second wound pole 44, 50 and a third reluctant pole 45, 51.
• two wound poles are separated by at least one reluctance pole.
• a wound pole and a magnet pole are separated by at least one reluctance pole.
• the poles 40, 46 are similar to the poles 20, 30, 34, 26 of FIG. 2, while the reluctance poles are similar to those of FIG. 1a.
• the polarities of the elementary pattern are: NSSSSS-NSSSSS for a 12-pole rotor.
• your polarities become: NSNSNS and the machine provides a power greater than the base power supplied by the magnets alone.
• the number of Na magnets is less than the number of windings Nb.
• This exemplary embodiment illustrates another means of achieving partial negative defluxing when all the magnets can be completely subjected to the magnetic flux of the wound poles.
• the priming speed can be modified and by modulating the numbers Na of magnets, Nb of windings and Nme of patterns, the defluxing of the rotor is controlled.
• modulations can be made according to predefined criteria such as the type of engine to be powered, the number of electrical equipment and electrical consumers of the vehicle, the desired safeties (not overheating of the battery, etc.).
• modulations can also be made according to the size of the rotor. Indeed, in certain cases where the size of the rotor is limited, it is not possible to have, for example, sixteen poles but only twelve or even less; in this case it is interesting to have more magnets than coils or a particular distribution of magnets and coils, because a coil takes up more space than a magnet. On the other hand, a magnet has a higher cost price than a coil. Consequently, the more magnets are placed in an elementary pattern, the more the rotor has a high cost price.
• all the coils belonging to the same elementary pattern are not fed simultaneously, as shown for example in FIG. 3.
• one coil is fed on two.
• this defluxing being able to be total or partial.
• a succession of magnetic poles N-S or S-N created by at least one magnet for example having a radial effect as shown in FIGS. 4 and 5, is inserted.
• FIG. 4 illustrates a variant of FIG. 2 in which between the elementary patterns me1 and me2, constituted respectively by the poles 1 to 6 and 9 to 16, two South-North poles have been inserted at the level of the poles 7.8 and 15.16.
• me1 and me2 constituted respectively by the poles 1 to 6 and 9 to 16
• two South-North poles have been inserted at the level of the poles 7.8 and 15.16.
• the magnetic poles added between two elementary patterns must advantageously be arranged so as to obtain a succession of poles NSNSNS ... when the excitation current is positive so as to obtain a maximum power output.
• FIG. 5 illustrates another exemplary embodiment of the variant produced from the embodiment of FIG. 3.
• me3 and me4 there is inserted between the two elementary patterns me3 and me4, at poles 7 and 8 and 15 and 16, two North-South magnetic poles.
• these magnets inserted between two elementary patterns can be of different polarity to the magnets belonging to the elementary patterns. Even two, the magnets interposed between the elementary patterns can also be of reverse polarities.
• a rotor with mixed excitation may comprise between at least one elementary pattern at least one North-South pole made by at least one magnet whose polarity and its position advantageously allows the electric machine to produce a maximum power during a flux removal. positive.
• a North-South pole interposed between at least one elementary pattern can be constituted by two contiguous magnets of opposite polarity.
• This arrangement constitutes a variant of the previously described intercalated north-south poles constituted by a magnet pole and a reluctance pole.
• the rotor 200 comprises a body of magnetic material provided, on the one hand, with notches for housing the excitation windings and, on the other hand, housings for the mounting permanent magnets.
• the notches are grouped in pairs to delimit the salient poles 22, 28, 42,43, 44,48, 49, 50 around which electrical wires, for example copper, are wound, to form the excitation windings.
• the rotor body is produced in the form of a packet of sheets perforated centrally for forced mounting on the shaft 15, advantageously knurled for this purpose.
• the aforementioned notches and housings are therefore easily produced by cutting.
• Passages are made below at least one magnet ( Figures 2 and 3) for passage of assembly members, such as tie rods, sheets.
• the excitation windings have an oblong shape axially. Note the presence of openings (not referenced) in the vicinity of the shaft 15 ( Figures 2 and 3) for channeling the magnetic fluxes and forming closed magnetic circuits also circulating in the stator of the machine described below.
• the housings of the magnets extend at the external periphery of the rotor and generally have a section of rectangular shape whose lengths are perpendicular to a radius of the rotor.
• the magnets advantageously have a shape complementary to their housings by being, as mentioned above, surface to generate radial magnetic fluxes.
• other arrangements can be provided to create radial magnetic fluxes.
• the rotary electrical machine comprises, as mentioned above, a stator 100 at least partially surrounding the rotor 200 and provided with a body 101 of magnetic material, for example in the form of a package of sheets.
• This stator 100 is advantageously polyphase and therefore comprises armature windings 103 mounted in notches 102 produced in its body 101. The notches
• teeth 104 which receive the magnetic flux emitted by the rotor and which passes through a small annular air gap present between the external periphery of the rotor and the internal periphery of the stator. It is for this reason that the magnetic fluxes have been represented by loops.
• Permanent magnets consist, for example, of ferrites or rare earths or a combination of the two.
• the electric machine is in one embodiment an alternator of a motor vehicle making it possible to transform mechanical energy into electrical energy, its stator being an induced stator and the rotor an inductive rotor.
• the alternator is reversible and is therefore configured to constitute an electric motor making it possible in particular to start the heat engine of the motor vehicle. This type of alternator is called an alternator-starter.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Permanent Magnet Type Synchronous Machine (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)
• Synchronous Machinery (AREA)

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• 2002
  • 2002-08-14 FR FR0210345A patent/FR2847087B1/fr not_active Expired - Fee Related
• 2003
  • 2003-08-13 MX MXPA05001704A patent/MXPA05001704A/es active IP Right Grant
  • 2003-08-13 JP JP2004528608A patent/JP2005536176A/ja active Pending
  • 2003-08-13 US US10/524,481 patent/US7701104B2/en not_active Expired - Fee Related
  • 2003-08-13 WO PCT/FR2003/002522 patent/WO2004017496A2/fr active Application Filing
  • 2003-08-13 KR KR1020057002357A patent/KR20050035881A/ko not_active Application Discontinuation
  • 2003-08-13 EP EP03758234A patent/EP1529334A2/fr not_active Withdrawn

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