Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/20—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium
  • H02K5/203—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium specially adapted for liquids, e.g. cooling jackets

Definitions

• the present invention relates to the field of rotating electrical machines, in particular the cooling of rotating electrical machines.
• It relates more particularly to the cooling of a closed rotary electrical machine with synchronous reluctance.
• a rotating electrical machine conventionally comprises a fixed part, the stator, and a rotatable part, the rotor, arranged coaxially one inside the other.
• the rotor is generally housed inside the stator which carries electrical windings generating a rotating magnetic field for rotating the rotor.
• the rotor typically comprises a body formed of a stack of sheets, and placed on a rotating shaft. These sheets include housings for permanent magnets or coils forming magnetic poles at the periphery of the rotor. Magnets may appear on the surface of the rotor or be completely integrated within the rotor.
• the rotor may comprise permanent magnets housed inside flow barriers carried by this rotor, these flow barriers being typically empty spaces. It is also called synchro-reluctant machine assisted by permanent magnets.
• the main sources of heat in an electrical machine are the windings, and in particular the coil heads, on the stator side, and the magnets and the shaft on the rotor side.
• the stator winding is also sensitive to temperature rise: the higher the winding temperature, the lower the electrical conductivity of the copper and the service life of the winding.
• FIG. 1 illustrates a stator water cooling system of an electric machine according to the prior art.
• the electric machine 1 comprises active parts of the electric machine 2 (stator 6 and rotor 7), and a cooling system.
• the cooling system comprises a channel 8 in which circulates a coolant (here water), an outer casing 3 of the cooling system, an inlet 4 of the coolant and an outlet 5 of the coolant.
• the coolant circulation channel 8 comprises a coil 9 illustrated in FIG. 2.
• the coil 9 comprises a plurality of juxtaposed turns of constant passage section. For this coil 9, the inlet 4 of the coolant and the outlet 5 of the coolant are not located at the ends of the coil 9. This results in zones 10, in which the coolant circulates little or no, which causes poor efficiency of the cooling system in the zones 10 (little heat exchange in the zones 10).
• a general objective of the invention is to provide efficient cooling of a closed rotary electrical machine, in particular of a synchronous reluctance closed rotary electrical machine, also known as synchro-reluctant, in order to guarantee performance and efficiency.
• a closed rotary electrical machine in particular of a synchronous reluctance closed rotary electrical machine, also known as synchro-reluctant
• IP high protection rating
• the present invention aims to improve the cooling of an electric machine, more specifically the cooling of the outer portion of the stator.
• the present invention relates to a rotating electrical machine comprising a rotor, a stator and a cooling device.
• the cooling device comprises a circulation channel of a heat transfer liquid.
• the channel includes substantially circumferential areas, wherein the channel is subdivided into a plurality of passages.
• the channel further comprises substantially helical zones in which the channel is not subdivided.
• the subdivision of the channel makes it possible to increase the exchange surface (and thus the efficiency of the cooling system), but also the speed of the fluid locally, increasing the convective coefficients.
• the helical zones without subdivision make it possible to limit the losses of load. Thus, it is possible to maintain a good performance of the electric machine.
• the present invention relates to a rotating electrical machine comprising a stator disposed in a housing, a rotor arranged within said stator, and a cooling device of the outer portion of said stator, said cooling device being substantially cylindrical and said cooling device comprising a circulation channel of a heat transfer fluid arranged around said stator.
• Said circulation channel of said coolant comprises at least one substantially circumferential zone, wherein said channel is subdivided into several passages, and at least one substantially helical zone, wherein said heat transfer fluid circulation channel is not subdivided.
• said cooling device comprises an inlet and an outlet of said heat transfer fluid connected to said heat transfer fluid circulation channel, said inlet and said outlet being arranged at the ends of said heat transfer fluid circulation channel.
• said cooling device comprises an inlet and an outlet of said heat transfer fluid connected to said channel, said inlet and said outlet being arranged on a generatrix of said cylinder formed by said cooling device.
• said at least one substantially helical zone is aligned with said inlet and said outlet of said heat transfer fluid.
• the channel is subdivided into two passages.
• said passages of a circumferential zone have a substantially identical section and are substantially parallel to each other.
• said channel and said passages are delimited by ribs formed on an inner casing of said cooling device.
• said cooling device comprises an outer casing having a smooth tubular shape.
• said channel comprises between two and six circumferential zones, preferably three or four circumferential zones.
• said cooling device has a length substantially equal to the axial length of the body of said stator.
• said heat transfer fluid comprises water.
• said electrical machine is of the synchronous reluctance type.
• Figure 1 already described, illustrates an electric machine equipped with a cooling system according to the prior art.
• Figure 2 already described, illustrates a coil of a cooling system of an electric machine according to the prior art.
• FIG. 3 illustrates an electric machine equipped with a cooling system according to one embodiment of the invention.
• FIG. 4 illustrates, in sectional view, an electric machine equipped with a cooling system according to one embodiment of the invention.
• FIG. 5 illustrates an external casing of a cooling device according to one embodiment of the invention.
• the present invention relates to a rotating electrical machine, preferably a synchronous reluctance machine.
• the electric machine comprises:
• the stator may comprise a stator body supporting magnetic flux generators such as windings, a rotor arranged within the stator, preferably the rotor is arranged coaxially with the stator, the rotor comprises magnetic flux generators such as magnets,
• the cooling device is arranged around the stator, the cooling device comprises a circulation channel for a heat transfer fluid, in particular a heat-transfer liquid, for example water, to cool the stator.
• a heat transfer fluid in particular a heat-transfer liquid, for example water
• stator windings
• rotor magnets
• flux generators make it possible to generate a magnetic field that makes it possible to rotate the rotor in association with the magnetic field generated by the magnets and / or the rotor coils.
• the stator body and the rotor body can be made by a stack of sheets.
• the channel of the cooling device comprises at least one substantially circumferential zone, wherein said channel is subdivided into several passages.
• Circumferential zone is understood to mean an area in which the coolant circulates in a substantially circumferential direction of the cooling device.
• the heat exchange surface is increased thanks to the subdivisions, which causes an increase in the efficiency of the cooling device.
• the heat transfer fluid velocity is increased, which improves the convective coefficients for the heat exchange.
• the channel of the cooling device comprises at least one substantially helical zone, in which said channel is not subdivided.
• Helical zone means an area in which the heat transfer fluid circulates in a substantially helical direction, that is to say a direction inclined with respect to the circumferential direction.
• the channel comprises an alternation of circumferential zones and helical zones to form the channel; the helical zones connect the circumferential zones.
• the coolant circulates successively in passages of small section in a circumferential direction, then in a channel of greater section in a direction inclined relative to the circumferential direction.
• the cooling device may comprise an inlet and an outlet of the coolant. The inlet and the outlet are connected to the circulation channel of the coolant.
• the inlet and outlet of the coolant can be arranged at both ends of the channel; there is no portion of the channel without circulation of the liquid unlike the prior art of Figure 2. With this configuration, the coolant can circulate throughout the channel. In this way, there is a better efficiency of the cooling device, and all the available exchange surface is used.
• the inlet and the outlet of the coolant are aligned on a generatrix of the cylinder formed by the cooling device.
• the inlet and outlet of the heat transfer fluid are arranged on one side of the electrical machine, which facilitates the connection, and limits the bulk.
• At least one helical zone can be aligned with the inlet and outlet of the coolant.
• all the helicoidal zones can be aligned with the inlet and the outlet of the coolant.
• the inlet and the outlet are located on a helical zone, and in this way, the channel is inclined as soon as the heat transfer fluid arrives.
• the helical zones can be located on this generator.
• the channel is subdivided into two passages.
• the channel is subdivided into three or four passages.
• the passages have an identical section and are parallel to each other.
• the channel and the passages may be delimited by ribs formed on an internal casing of the cooling device.
• the inner casing of the cooling device has a substantially cylindrical shape, with ribs arranged on its outer surface and directed towards the outside of the electric machine. In the circumferential zones, the ribs are substantially circumferential, and in the helical zones, the ribs are substantially helical.
• the cooling device may comprise an outer casing having a smooth tubular shape.
• the outer casing of the cooling device does not include any specific relief to form the channel.
• the inner and outer casings of the cooling device may be provided with means for fixing one to the other (for example by screwing, threading, etc.) and with sealing means. (for example by O-rings), so as to close the cooling device in a sealed manner.
• the channel may comprise between two and six circumferential zones.
• the channel may comprise three or four circumferential zones.
• the number of circumferential zones is greater than the number of helical zones to limit the pressure drops.
• the cooling device may have a length substantially equal to the axial length of the stator body.
• the electric machine can be of any type.
• the electrical machine according to the invention can be a synchronous reluctance closed rotary electrical machine, also called a synchronous-reluctant, in particular a synchronous reluctance closed rotary electrical machine, having a high protection index "IP" in accordance with the standard EN 60529, typically an IP67 degree of protection.
• IP protection index
• FIG. 3 illustrates, schematically and in a nonlimiting manner, an electric machine 1 according to one embodiment of the invention.
• Figure 3 is a three-dimensional view of the electric machine 1 without outer casing of the cooling device.
• the electric machine 1 comprises an inner casing 1 1 of the cooling device, a front flange 15 and a rear flange 16, inside which are arranged the rotor and the stator.
• the inner casing 1 1 of the cooling device, the front flange 15 and the rear flange 16 are sealed.
• the inner casing 1 1 of the cooling device has substantially a cylindrical shape, and comprises a channel 8, an inlet 4 of the coolant, and an outlet 5 of the fluid coolant.
• the inlet 4 and the outlet 5 of the coolant are arranged on a generatrix of the inner casing 1 1 of the cooling device.
• the channel 8 consists of circumferential zones and helicoidal zones 12.
• the helical zones 12 are arranged on the generatrix of the inner casing 1 1 of the cooling device which connects the inlet 4 and the outlet 5 of the coolant.
• the channel 8 is subdivided into two passages 13.
• the channel 8 is not subdivided.
• the channel 8 and the passages 13 are delimited by ribs 14 formed on the inner casing 1 1 of the cooling device.
• FIG. 4 illustrates, schematically and in a nonlimiting manner, an electric machine 1 according to the embodiment of FIG. 3.
• FIG. 4 illustrates, schematically and in a nonlimiting manner, an electric machine 1 according to the embodiment of FIG. 3.
• FIG. 4 illustrates, schematically and in a nonlimiting manner, an electric machine 1 according to the embodiment of FIG. 3.
• FIG. 4 illustrates, schematically and
• the electrical machine 1 comprises a stator 6, a rotor 7 arranged coaxially within the stator 6, a cooling device arranged around the stator 6, a front flange 15 and a rear flange 16.
• the inner casing 11 of the device the front flange 15 and the rear flange 16 are sealed.
• the inner casing 1 1 and the two flanges 15 and 16 can be fixed by means of screws.
• the substantially cylindrical cooling device comprises an inner casing 1 1, a channel, an outer casing 19, an inlet 4 of the coolant, an outlet 5 of the coolant.
• the channel consists of helical zones 12 (not subdivided) and circumferential zones, in which the channel is subdivided into two passages 13.
• the helical zones 12 are located in the upper part of the electrical machine, between the inlet 4 and the outlet 5 of the coolant.
• the cooling device allows heat exchange on an exchange surface 17 (shaded area) which covers the body of the stator 6 and the coil heads 18 of the stator 6. This exchange surface 17 allows in particular the cooling of the cylinder head external 20 of the stator 6, which comprises the windings.
• Figure 5 illustrates, schematically and without limitation, an outer casing 19 for a cooling device of an electric machine according to the embodiment of Figures 3 and 4.
• the outer casing 19 has substantially a tubular shape.
• the outer casing 19 of the cooling device comprises a smooth inner surface 23, that is to say without specific relief.
• the outer casing 19 of the cooling device comprises two orifices 21 and 22.
• the orifice 21 is provided for the inlet of the coolant
• the orifice 22 is provided for the outlet of the coolant.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Cooling System (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=60923592

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (8)

• 2017
  • 2017-08-24 FR FR1757858A patent/FR3070558B1/fr active Active
• 2018
  • 2018-07-06 WO PCT/EP2018/068390 patent/WO2019037930A1/fr unknown
  • 2018-07-06 CN CN201880054574.3A patent/CN111247724A/zh active Pending
  • 2018-07-06 EP EP18735330.5A patent/EP3673566A1/de not_active Withdrawn

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