Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
  • H02K3/28—Layout of windings or of connections between windings
• • 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
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/16—Stator cores with slots for windings
• • 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
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
  • H02K1/185—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures to outer stators
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K19/00—Synchronous motors or generators
  • H02K19/16—Synchronous generators
  • H02K19/34—Generators with two or more outputs
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/24—Casings; Enclosures; Supports specially adapted for suppression or reduction of noise or vibrations

Definitions

• Polyphase rotary electrical machine such as an alternator or alternator-starter, in particular for a motor vehicle.
• the invention relates to a polyphase rotary electrical machine such as an alternator or alternator-starter, in particular for a motor vehicle, of the type comprising, inside a casing, a stator surrounding a rotor, the stator comprising a three-phase winding in star and a three-phase triangle winding, the outputs of which are connected to rectifier bridges mounted in parallel between earth and the output terminal of the rotary electric machine, the two windings being received together in notches in the stator.
• These two three-phase windings, one connected in star, the other connected in triangle form a device of composite stator windings.
• the state of the art is thus limited to mentioning some specific positive effects which the device for composite stator windings provides.
• the object of the invention is to go further by proposing possibilities of optimizing the performance of a rotary electric machine as defined above, by virtue of the device of composite stator windings.
• the rotary electric machine according to the invention in which the ratio of the numbers of the turns of the star and triangle windings is chosen so that the number of turns of each winding are whole numbers, while maintaining the ratio of these numbers as close as possible to the value 3, is characterized in that the number of turns of the star winding and the number of turns of the triangle winding are 3 and 5 respectively.
• the diameter of the wire of the star winding is different from the diameter of the wire of the triangle winding and the ratio of the diameters is chosen so as to be close to the optimal ratio of 3 of the resistances of the windings, and the diameters of the windings of star and triangle stator are chosen to obtain a filling coefficient of the notches greater than 50%.
• the star winding is formed by two wires in parallel, advantageously wound in a distributed manner.
• the turns of the star winding of a stator notch are arranged at the notch opening, in a distributed manner, while the turns of the triangle winding are at the bottom of one notch.
• the number of magnets is less than the number of poles and the magnets are arranged symmetrically in the center of the rotor.
• FIG. 1 is an axial sectional view of a rotary electrical machine of the prior art
• - Figure 2 illustrates the electrical diagram of a rotary electrical machine whose stator winding comprises a three-phase star winding and a three-phase triangle winding, according to the prior art
• - Figure 3 is a sectional view, broken away, of the stator of a rotary electric machine according to one invention
• - Figure 4 is a perspective view of a rotor of a rotary electrical machine according to the invention
• FIG. 5 is a curve representing the thermal state T of the machine as a function of the ratio R of the numbers of the turns of the star and triangle windings.
• a rotary electrical machine is briefly described below, in this case an alternator here of the three-phase type, in particular for a motor vehicle with an internal combustion engine, of the state of the art, to which the invention is applicable.
• the alternator can be reversible and consist of an alternator-starter in particular for starting the engine of the vehicle.
• alternator mode When the machine operates in alternator mode it transforms mechanical energy into electrical energy like any alternator.
• electric motor mode in particular in starter mode to start the heat engine of the motor vehicle, it transforms electrical energy into mechanical energy.
• This machine essentially comprises a casing 1 and, inside thereof, a rotor 2 integral in rotation with a shaft 3 and a stator 4 which surrounds the rotor and comprises a body in the form of a pack of sheets provided notches, here of the semi-closed type, for the mounting of the stator windings forming on either side thereof a chignon indicated at 5.
• These windings here comprise a three-phase star winding and a three-phase winding in a triangle arranged as described below to form a composite stator winding device.
• the rotor is produced in the example shown in the form of a claw rotor, as described for example in documents TS 2002/0175589 A1 and EP 0 454 039 A1, comprising two pole wheels 7, 8 axially juxtaposed and each having a transverse flange provided at its outer periphery with teeth 9 of trapezoidal shape axially aligned towards the flange of the other pole wheel, the tooth of a pole wheel penetrating into the space existing between two adjacent teeth 9 of the other pole wheel, so that the teeth of the pole wheels are nested.
• An excitation winding 10 is located axially between the flanges and the pole wheels 7, 8.
• a rotor part in the form of a cylindrical core, which could be separate from the flanges or be in two parts each belonging to one of the flanges as shown in Figure 1
• the rotor of ferromagnetic material is magnetized and becomes an inductive rotor with the formation of magnetic poles at the teeth of the pole wheels.
• This inductor rotor creates an alternating induced current in the induced stator when the shaft 3 rotates.
• the rotor may have salient poles, as described for example in document WO 02/054566, and then comprises several excitation coils each wound around such a pole.
• the shaft 3 of the rotor 2 carries at its front end a pulley 12 belonging to a movement transmission device with at least one belt between the alternator and the heat engine of the motor vehicle, and at its rear end 13 connected slip rings by wire connections at the ends of the rotor excitation coil (s).
• Brushes belong to a brush holder shown generally at 14 and are arranged so as to rub on the slip rings.
• the brush holder is connected to a voltage regulator.
• the housing 1 is in two parts, namely a front bearing 16 adjacent to the pulley 12 and a rear bearing 17 carrying the brush holder, the voltage regulator and rectifier bridges described below.
• the bearings are hollow in shape and each have a central ball bearing 19 and 20 respectively for the rotational mounting of the shaft 2 of the rotor 3.
• the bearings are, in the machine shown, perforated to allow cooling of the alternator by air circulation.
• the rotor carries at least at one of its axial ends a fan intended to ensure this air circulation.
• a fan marked 23 is pre-seen on the front end face of the rotor and another fan 24, more powerful, on the rear face, each fan being provided with a plurality of blades indicated at 25 and 26
• the alternator can also be water cooled, the casing then being configured to include an appropriate water circulation channel.
• a rotary electrical machine of the type shown in FIG. 2 and to which the invention is applicable comprises a device for composite stator windings, which comprises, as shown in FIG.
• a three-phase star winding 28 and a winding three-phase triangle 29 whose outputs are connected to rectifier bridges 30 and 31 respectively comprising rectifier elements such as diodes 32 or MOSFET type transistors, especially when the machine is of the reversible type and consists of an alternator-starter as described for example in document FR A 2 745 445 (US A 6 002 219).
• each three-phase winding has three arms each consisting of a winding of a phase.
• the three-phase star winding has three arms connected in a star and therefore a common input and three outputs electrically connected to bridge 30.
• the three-phase winding in a triangle has three arms connected in a triangle, that is to say electrically connected in pairs at each of the vertices of the triangle, each vertex constituting an entry.
• the outputs of this three-phase winding are electrically connected to the bridge 31.
• the rectifier bridges are mounted in parallel between the ground and the continuous output terminal 33. These bridges are carried by the rear bearing 17 of the alternator as visible for example in FIG.
• the bridges are full-wave bridges of the Graetz type. These bridges make it possible in particular to rectify the alternating current produced in the windings of the stator in a direct current in particular for charging the battery of the motor vehicle.
• the number of turns of the triangle winding 29 is 3 times greater than the number of turns of the star winding 28.
• the ratio between the sections of the turns of the 1 ' triangle winding and the turns of the star winding is 1 / V3. Since the diagram of FIG. 2 is known, for example from French patent No. 2,737,063, it will not be described below in more detail.
• the turns of the star 28 and triangle 29 windings are arranged in the same notches denoted 35, the turns of the triangle winding being placed near the opening 36 of the notches, while the turns of the star winding 28 are placed at the bottom.
• the rotor 2 ( Figure 4) has eight teeth 9 per pole wheel and therefore eight pairs of poles. 48 notches are therefore provided in the stator body, that is to say half as many notches as in the solutions described in documents US 2002/0175589 A1 and EP 0 454 039 A1 mentioned above.
• the rotor can, depending on the applications, comprise 6, 7, 10 or 12 pairs of poles and the stator 36, 42, 60 or 72 pairs of poles.
• two notches for receiving the second and third arms of the winding respectively.
• each notch 35 comprises, in a known manner, a not referenced notch insulator for isolating the wires from the windings with respect to the stator body and that the opening 36 of each notch 35 is sufficiently wide to allow the wires of the windings to pass .
• This entry is in a known manner closed by a not referenced notch block.
• This wedge is advantageously elastic to exert a clamping action on the wires of the windings.
• the object of the invention is to improve rotary electrical machines of the type shown in FIGS. 1 and 2 by optimizing their performance, in particular by means of an appropriate configuration of the device for composite stator windings, and of additional constructive measures, as will be described below.
• the invention is essentially based on the discovery that the choice of the number of turns received in each notch of the stator, the star 28 and triangle 29 windings has a considerable impact on the performance of the machine.
• the number of turns must be as small as possible but that the ratio of the number of turns of the winding in a triangle relative to the number of turns the star winding must be as close as possible to the optimal value equal to ⁇ 3. Measurements made it possible to establish the characteristic curve represented in FIG.
• the abscissa thus carries different ratios or pairs of turns that can be envisaged as a function of the two conditions and taking into account that each number of turns must be an integer.
• the abscissa carries the possible ratios for numbers of turns of the star winding 2, 3, 4.
• the curve has the shape of a bell opening upwards, with a minimum value between the 5/3 and 7/4 ratios, where the ratio has the optimal value is ⁇ 3.
• the thermal degradation to the right of the value ⁇ 3 during the increase in the number of turns of the star winding is explained by the fact that the bun which then becomes large does not allow the cooling air to pass, which has could be measured as an increase in the stator iron temperature.
• To the left of the value ⁇ 3 the thermal degrades because for a number of turns of winding in star equal to 2, it is necessary to associate four turns of winding in triangle, which involves a report equal to 2 instead of the report optimal "v3.
• the filling coefficient of the notches is greater than or equal to 50%, and the diameter of the wires is as large as possible to ensure good ventilation of the buns.
• the positioning of the turns in the notches is easier for wires of a smaller diameter, it is planned to make the turns of the star winding with wires in parallel.
• the number of wires in parallel must be as low as possible to ensure good ventilation of the buns.
• a distributed winding consists of winding the wire in the notches of the stator body in a circumferential direction, then after a turn of the stator body to wind the wire in the notches of the stator body in the other circumferential sense.
• the triangle winding could be made with a 1.6 mm wire and the star winding with a 2 wire, 24 mm.
• the realization in parallel of the turns of the star winding could allow the use for the star winding wires and the triangle winding wires of wires of diameters of 1.6 mm and 1.7 mm respectively.
• the arrangement of the triangular winding wires near the opening 36 of the notches 35 and the star winding wires in the bottom of the notches ensures a good balance in electrical flow.
• a rotor having the configuration according to FIG. 4.
• This rotor comprises, in a manner known per se and for example described in the French Patent No. 2,784,248, interposed between two teeth 9 adjacent to the periphery of the stator such as the stator 2 according to FIG.
• a certain number of permanent magnets 38 by choosing the number of these magnets so that it is less than the number of poles of the rotor and that their arrangement is symmetrical with respect to the axis of the rotor.
• This arrangement of the invention is also applicable to rotors of the salient pole type.
• Figure 4 there are provided four pairs of magnets 38 for eight pairs of poles. It should be noted that it is also advantageous in the context of the invention to provide at the external periphery of the stator body, in the form of a sheet bundle, an elastic system for filtering vibrations, with a seal at the front.
• the invention provides, compared to the state of the art, multiple advantages, such as an improvement in the specific power, a reduction in the magnetic noise and the ripple rate. These advantages are obtained by the offset of 30 electrical degrees of the two star and triangle windings in the stator while respecting a ratio of the number of turns of "V3 and a resistance ratio of the windings of l /" V3.
• the machine is in Figure 1 to be air cooled by a front fan and a more powerful rear fan.
• the power of the machine can be further increased by using more efficient fans such as fans obtained by superposition of two elementary fans each comprising a series of blades as described for example in the document FR A 2 741 912 and as shown in the figure. 1 (rear fan).
• the wire diameter of the star winding is different from the wire diameter of the triangle winding.
• the star winding could be wound with two wires in hand and the triangle winding with one wire in hand.
• the star winding is wound in distributed corrugation and the wires used are round wires to improve the cooling of the stator chignon.
• the wire section is greater than or equal to 1.5 mm.
• windings of different axial height are provided at the buns.
• one of the windings preferably the one located in the vicinity of the bottoms of the notches, extends in axial projection relative to the other winding at each bun.
• the star winding is placed in the bottom of the notches.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Windings For Motors And Generators (AREA)
• Motor Or Generator Cooling System (AREA)
• Synchronous Machinery (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34355304

Family Applications (1)

Country Status (8)

Families Citing this family (16)

Citations (2)

Family Cites Families (14)

• 2003
  • 2003-09-05 FR FR0310545A patent/FR2861225B1/fr not_active Expired - Fee Related
• 2004
  • 2004-09-03 WO PCT/FR2004/002214 patent/WO2005029679A1/fr active Application Filing
  • 2004-09-03 KR KR1020067004630A patent/KR20060072138A/ko not_active Application Discontinuation
  • 2004-09-03 CN CNB2004800254426A patent/CN100530899C/zh not_active Expired - Fee Related
  • 2004-09-03 US US10/570,632 patent/US7531935B2/en not_active Expired - Fee Related
  • 2004-09-03 EP EP04787271A patent/EP1661230A1/de not_active Withdrawn
  • 2004-09-03 MX MXPA06002518A patent/MXPA06002518A/es unknown
  • 2004-09-03 JP JP2006525160A patent/JP4620666B2/ja not_active Expired - Fee Related

Patent Citations (2)

Non-Patent Citations (1)

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