Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/30—Windings characterised by the insulating material
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/32—Windings characterised by the shape, form or construction of the insulation
  • H02K3/34—Windings characterised by the shape, form or construction of the insulation between conductors or between conductor and core, e.g. slot insulation
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/32—Windings characterised by the shape, form or construction of the insulation
  • H02K3/40—Windings characterised by the shape, form or construction of the insulation for high voltage, e.g. affording protection against corona discharges
• • 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

Definitions

• the present invention relates to a rotary electric machine stator that includes: a stator core that has slots; and stator coils that are wound around parts of a stator core so as to be inserted in the slots.
• stator of a rotary electric machine a structure is available that a stator core in which a groove that is referred to as a slot and extends in a radial direction is provided at plural parts in a circumferential direction; and stator coils that are wound around the plural parts of the stator core in the circumferential direction so as to be inserted in two slots that are spaced from each other in the circumferential direction are provided and the stator coils are wound on the stator core by distributed winding or concentrated winding.
• JP 2008-236924 A discloses a coil that constitutes a stator.
• the coil is made by covering a coil conductor that is formed by winding a wire conductor with an electric field relaxation layer, and then coating slot straight portions of the coil that are disposed in the slot of the stator core with an insulation layer and coating coil end portions that are disposed in a coil end with another insulation layer, and finally coating them again with an electric field relaxation layer.
• the slot straight portion and the coil end portion are designed to be different in the thickness or in the material type of the insulation layer from each other.
• the thickness of the insulation layer of the slot straight portions is determined such that a partial discharge inception voltage (PDIV) of the slot straight portion is higher than the peak voltage to ground during the operation of the rotary electric machine.
• the thickness of the insulation layer of the coil end portions is determined such that a PDIV of the coil end portion is higher than the peak interphase voltage during the operation of the rotary electric machine.
• a voltage due to generation of a steep surge voltage that is higher than the normal voltage that occurs when the motor is driven by an alternating current is concentrated, triggered by On-Off operation and the like of a switching element of an inverter, and thus the applied voltage to the specific coil may increase.
• enhancing the speed of switching is intended to reduce inverter losses, and therefore the surge voltage tends to increase.
• the specific coil and another coil of the same phase as that of the specific coil are adjacent to each other in the same slot, the potential difference between adjacent coils increases due to the effect of the aforementioned surge voltage.
• an insulating paper is provided in the slot to separate the coils of the same phase; however, it may cause reduction of the coil space factor in the slot or increase of slot length and the size of the rotary electric machine.
• a space referred to as a slot tip gap that is provided to an inner end of the stator in a radial direction in the slot is reduced, and a copper eddy current loss may increase.
• the present invention provides a rotary electric machine stator, with which it is possible to effectively suppress the partial discharge between coils even in a case where parts of different coils are placed in the same slot in the rotary electric machine stator.
• a rotary electric machine stator includes: a stator core that has a plurality of slots; and a plurality of stator coils that are wound on a plurality of parts of the stator core so as to be inserted in the plurality of slots and are connected in series, in which the plurality of stator coils include a first coil that has a first insulating layer with a first dielectric constant and a second coil that has a second insulating layer with a second dielectric constant lower than the first dielectric constant, the plurality of slots include a reference slot in which the first coil is inserted, and an input terminal side slot, in which an input terminal side stator coil that is one of the stator coils and that is connected on an input terminal side with respect to the first coil in terms of an order of series connection, is inserted, and at least part of the stator coils that are inserted in the input terminal side slot include the second coil.
• the plurality of stator coils include a first coil that has a first insulating layer with a first dielectric constant
• the input terminal side stator coil that is the second coil, and a neutral point side stator coil that is one of the stator coils and that is connected on a neutral point side with respect to the second coil in terms of the order of the series connection may be inserted in the input terminal side slot.
• the neutral point side stator coil may have an insulating layer with a dielectric constant lower than the first dielectric constant of the first insulating layer.
• the "insulating layer with a dielectric constant lower than the first dielectric constant of the first insulating layer” may be the same as the second insulating layer or the insulating layer with a dielectric constant different from that of the second insulating layer (the same also applies to the entire specification and the claims).
• the second coil and the input terminal side stator coil may be inserted in the input terminal side slot.
• each of the stator coils is formed in a coil shape and include a conductor coil unit that has a placed-in-slot section that is provided at each end of the coil unit in a width direction with a predetermined unit coil spacing provided between the placed-in-slot sections
• the plurality of stator coils include at least one loop of a coil unit ring that is constructed by connecting ends of a plurality of the conductor coil units of the same phase in an annular shape
• the conductor coil unit includes a one coil end portion that is disposed on one end side in an axial direction of the stator core, the one coil end portion has: two slot passing sections that can pass through corresponding two of the slots in the axial direction when the coil unit ring is fitted into the stator core from one axial end side of the stator core in the axial direction by inserting the placed-in-slot sections of the conductor coil unit into the corresponding two of the slots; and an inside connecting
• each of the stator coils includes a conductor segment coil that is constructed by joining a plurality of conductor segments in a coil shape, each of which includes, at its two ends, two parallel legs respectively having the placed-in-slot sections and that are inserted into the stator core from one axial side to the other axial side of the stator core so as to be aligned along a radial direction of the stator core in the two of the slots, the two of the slots being spaced from each other by a predetermined unit coil spacing;
• the plurality of stator coils include at least one loop of a segment ring section that is constructed by connecting ends of a plurality of the conductor segment coils of the same phase in an annular shape; and the placed-in-slot section that is provided in one of the conductor segment coils that is the second coil is inserted in the input terminal side slot, in which the placed-in-slot section that is provided to another conductor segment
• the second insulating layer may include an enamel resin that has a resin, in which polyimide and polyamide-imide are alloyed with each other, and the first insulating layer may include a material with a dielectric constant higher than the second dielectric constant of the second insulating layer.
• the first insulating layer may include an enamel resin that contains polyamide-imide
• the second insulating layer may include an enamel resin that contains polyimide
• At least part of the stator coils that are inserted in the input terminal side slot may have the second insulating layer or another insulating layer that has a resin in which filler is mixed.
• the rotary electric machine stator According to the present invention, even if the second coil and another coil are placed in the input terminal side slot where the voltage of the conductor of the coil to be inserted tends to be higher than that of the conductor of the coil to be inserted in the reference slot, a sufficiently high partial discharge inception voltage is ensured between the coils.
• the plurality of stator coils also include the first coil that has the first insulating layer with the first dielectric constant higher than the second dielectric constant, and therefore the cost does not increase excessively. Furthermore, there is no need to provide the insulating paper in the input terminal side slot in order to increase the aforementioned partial discharge inception voltage. Therefore, even if parts of different coils are inserted in the same slot, the partial discharge between the coils in the slot is suppressed more effectively.
• FIG. 1 is a perspective view that shows a rotary electric machine stator of a first embodiment according to the present invention
• FIG. 2 is a schematic perspective view that shows one conductor coil unit that constitutes the stator of FIG. 1;
• FIG. 3 is a schematic perspective view that shows only a coil unit ring that is removed from the rotary electric machine stator of FIG. 1 and where conductor coil units of one phase that is a U-phase are connected;
• FIG. 4 is a schematic diagram that illustrates an arrangement manner in which a first loop element and a fourth loop element of the coil unit ring of U-phase in FIG. 3 are placed in a stator core;
• FIG. 5 is a schematic diagram that illustrates an arrangement manner in which a second loop element and a third loop element of the coil unit ring of U-phase in FIG. 3 are placed in a stator core;
• FIG. 6A is a diagram that shows part of a connecting condition of the coil unit ring of U-phase in FIG. 3;
• FIG. 6B is a diagram that shows the rest of the connecting condition of the coil unit ring of U-phase in FIG. 3;
• FIG. 7 is a circumferentially partial, schematic perspective view that shows a state where the conductor coil unit of the first loop element of the coil unit ring of U-phase in FIG. 3 is wound on the stator core;
• FIG. 8 is a circumferentially partial, enlarged perspective view of FIG. 1, showing a partial cross section, that shows a state where parts of the conductor coil units are placed in the slots;
• FIG. 9A is a diagram that shows the stator in FIG. 8 in an extended state in the right and left circumferential direction in order to illustrate a first example, in which the dielectric constant of the conductor coil unit that is inserted in a reference slot is made different from that of the coil unit that is inserted in an input terminal side slot;
• FIG. 9B is a diagram that corresponds to FIG. 9A in order to illustrate first another example, in which the dielectric constant of the conductor coil unit that is inserted in a reference slot is made different from that of the coil unit that is inserted in an input terminal side slot;
• FIG. 9C is a diagram that corresponds to FIG. 9B in order to illustrate another first example, in which the dielectric constant of the conductor coil unit that is inserted in a reference slot is made different from that of the coil unit that is inserted in an input terminal side slot;
• FIG. 10 is a perspective view that shows a rotary electric machine stator of a second embodiment according to the present invention.
• FIG. 11 is a perspective view that shows one conductor segment that constitutes a segment ring section that is disposed in the stator of FIG. 10;
• FIG. 12 is a schematic perspective view that shows a manner in which the segment ring section of one phase that is U-phase is wound on the stator core in the stator of FIG. 10;
• FIG. 13 is a diagram that shows the segment ring section of U-phase that is removed from the rotary electric machine stator of FIG. 12;
• FIG. 14 is a diagram that shows a first loop element that is removed from the segment ring section of FIG. 13;
• FIG. 15 is a schematic diagram that illustrates an arrangement manner in which a first loop element of the segment ring section of FIG. 13 is placed in a stator core;
• FIG. 16 is a schematic diagram that illustrates an arrangement manner in which a second loop element of the segment ring section of FIG. 13 is placed in a stator core;
• FIG. 17 shows diagrams that illustrate two examples of cases where a durability compensating method for the rotary electric machine is changed in accordance with changes in elevation and motor temperature in an embodiment according to the present invention.
• a rotary electric machine stator (hereinafter merely referred to as a "stator") of the present embodiment is used to form a rotary electric machine such as an electric motor and a generator.
• the stator 10 includes a annular stator core 14 that has slots 12 at parts of an inner periphery in a circumferential direction, and coil unit rings 18, 20, and 22 of multiple phases that are three phases of U-phase, V-phase, and W-phase and that are formed by windings wound on the stator core 14 at multiple portions by distributed winding so as to be inserted in the slots 12.
• each of the coil unit rings 18, 20, and 22 of respective phases includes conductor coil units 16 that are a plurality of stator coils having placed-in-slot sections that are respectively inserted in the slots 12.
• a rotor (not shown) that is fixed to a rotating shaft is disposed inside the stator 10 in the radial direction, and a radial type rotary electric machine is formed by opposing the stator 10 and the rotor to each other in the radial direction.
• each coil unit 16 includes: placed-in-slot sections 24 that are respectively inserted in two slots 12 (FIG. 1) separated in the circumferential direction of the stator core 14 (FIG. 1); and two coil ends 26 and 28, and the coil unit 16 has an overall shape of a coil shape.
• the stator 10 of the present embodiment is a so-called "concentric unit coil winding type," and the coil unit rings 18, 20, and 22 of respective phases are formed by providing plural coil units 16 in each of which a coil wire that is constituted of a conductor line covered with an insulating layer is formed into a coil shape and by connecting the coil units 16 to form at least one loop (four loops in the case of the present embodiment) in the circumferential direction of the stator core 14.
• parts with reference symbols "u”, "v”, and "w” indicate the U-phase, the V-phase, and the W-phase, respectively.
• the coil unit rings 18, 20, and 22 of respective phases have, as shown in FIG. 2, plural coil units 16 each of which is one unit coil in which the coil wire is formed into the coil shape so as to have the placed-in-slot sections 24 that are provided at two end portions in a width direction (right and left direction of FIG. 2) with a unit coil spacing Dl in which the spacing between two slots 12 (FIG. 1) separated in the circumferential direction of the stator core 14 (FIG. 1) is determined to be constant in advance.
• the coil unit rings 18, 20, and 22 of respective phases (FIG. 1) are formed by connecting the coil units 16 in an annular shape and are disposed in the stator core 14 shown in FIG. 1.
• the stator core 14 is constituted of a dust core that is formed by a pressure forming of magnetic powder, a laminated body of metal plate such as a magnetic steel sheet, or the like.
• An arrangement of the coil unit rings 18, 20, and 22 is described next with reference to FIG. 3 through FIG. 7 by using the coil unit ring 18 of U-phase as a representative example.
• FIG. 3 is a schematic perspective view that shows only the coil unit ring
• the coil unit ring 18 that is removed from the rotary electric machine stator of FIG. 1 and where stator coils of one phase that is a U-phase are connected.
• the coil unit ring 18 is formed by connecting a plurality of loops (four loops in the example shown in the drawing), in each of which four coil units 16 each having a width of a predetermined unit coil spacing Dl (FIG. 2) in the circumferential direction are connected in an annular shape.
• basic form of the coil unit rings 20 and 22 of V-phase and W-phase (FIG. 1) is the same as that of the coil unit ring 18 of U-phase.
• the coil unit ring 18 of U-phase is formed of sixteen coil units 16 in which the coil wire that is constituted of the conductor line covered with the insulating layer is formed into the coil shape. That is, four coil units 16 that are connected into the annular shape to form one loop are constructed as the first loop element, and then, in the similar manner, four coil units 16 that are connected into the annular shape in the same direction as that of the first loop element are constructed as the second loop element, four coil units 16 that are connected into the annular shape in an opposite direction to that of the first and the second loop elements are constructed as the third loop element, and four coil units 16 that are connected into the annular shape in the same direction as that of the third loop element are constructed as the fourth loop element at the end.
• the coil unit ring 18 is formed by connecting the first through the fourth loop elements at their ends.
• the slots 12 (FIG. 1) in which the first loop element is placed are the same as the slots 12 in which the fourth loop element is placed, and the slots 12 in which the second loop element is placed are the same as the slots 12 in which the third loop element is placed; however, the slots 12 in which the first and the fourth loop elements are placed and the slots 12 in which the second and the third loop elements are placed are shifted from each other by one slot in the circumferential direction.
• FIG 4 is a schematic diagram that illustrates an arrangement manner in which the first loop element 30 and the fourth loop element 36 of the coil unit ring 18 of U-phase in FIG. 3 are placed in the stator core 14.
• FIG. 5 is a schematic diagram that illustrates an arrangement manner in which the second loop element 32 and the third loop element 34 of the coil unit ring 18 of U-phase in FIG. 3 are placed in the stator core 14.
• FIG 4 and FIG 5 show plan views of the stator core 14 and the coil units 16 on the outside of the stator core 14.
• Reference symbols Ul, U2, through U16 in FIG. 4 and FIG. 5 are coil numbers for identification of the sixteen coil units 16, where a winding start of the coil unit ring 18 of U-phase is a coil unit Ul that is a first unit coil, and a winding end is a coil unit U16 that is a sixteenth unit coil.
• the stator core 14 is formed of forty eight slots 12; however, slot numbers are given only to the slots that are necessary for explanation. In the description below, the slot numbers are indicated with a reference symbol S.
• each coil unit 16 is placed in two slots 12 that are separated from each other in the circumferential direction so that the coil unit 16 spans several slots 12. These two slots 12 are spaced by the predetermined unit coil spacing Dl.
• the coil unit Ul is a winding start of the coil unit ring 18 (FIG. 3), positioned on a power line side of the rotary electric machine, and connected to an input terminal side (IN side).
• the coil unit Ul is formed in a coil shape by winding plural turns (five turns, for example) of the coil wire between the slots S7 and S13.
• the winding start is connected to the input terminal (IN) side and wound in the slots 12 in the coil shape so as to be directed from an outer periphery side to an inner periphery side in the inner periphery side of the stator core 14, for example.
• the coil unit Ul is then connected to the coil unit U2 that is spaced in the circumferential direction at the winding end. That is, the coil unit U2 is formed by extending the wire from the slot S13 at the winding end of the coil unit Ul to the slot S19 that is spaced by the unit coil spacing Dl and winding plural turns of the coil wire between the slots S19 and S25 that are spaced from each other by the unit coil spacing Dl to form the coil shape. Successively, the aforementioned processes are repeated to form the coil units Ul through U4, and thus the first loop element 30 is formed.
• the number of turns of each of the coil units Ul through U4 is the same (this also applies in the following description).
• the coil unit U5 is shifted by one slot from the coil unit Ul and formed into the coil shape by winding plural turns of the coil wire between the slots S8 and S14.
• the winding end of the coil unit U5 is then connected to the coil unit U6. That is, the coil unit U6 is formed by extending the wire from the slot S14 at the winding end of the coil unit U5 to the slot S20 that is spaced by the unit coil spacing Dl and winding plural turns of the coil wire between the slots S20 and S26 that are spaced from each other by the unit coil spacing Dl to form the coil shape.
• the aforementioned processes are repeated to form the coil units U5 through U8, and thus the second loop element 32 is formed.
• the winding end of the second loop element 32 is connected to the coil unit U9 of the third loop element 34 shown in FIG. 5 on the outermost periphery side of the stator core 14.
• the coil unit U9 is formed into the coil shape by winding plural turns of the coil wire between the slots S44 and S38 so as to be shifted by one pitch with respect to the coil unit U8 of the second loop element 32.
• the winding end of the coil unit U9 is then connected to the coil unit U10.
• the coil unit U10 is formed by extending the wire from the slot S38 at the winding end of the coil unit U9 to the slot S32 that is spaced by the unit coil spacing Dl and winding plural turns of the coil wire between the slots S32 and S26 that are spaced from each other with the unit coil spacing Dl to form the coil shape. Successively, the aforementioned processes are repeated to form the coil units U9 through U12, and thus the third loop element 34 is formed.
• the winding end of the third loop element 34 is connected to the coil unit U13 of the fourth loop element 36 shown in FIG. 4 on the outermost periphery side of the stator core 14.
• the coil unit U13 is formed into the coil shape by winding plural turns of the coil wire between the slots S43 and S37 so as to be shifted by one pitch with respect to the coil unit U4 of the first loop element 30.
• the winding end of the coil unit U13 is then connected to the coil unit U14.
• the coil unit U14 is formed by extending the wire from the slot S37 at the winding end of the coil unit U13 to the slot S31 that is spaced by the unit coil spacing Dl and winding plural turns of the coil wire between the slots S31 and S25 that are spaced from each other by the unit coil spacing Dl to form the coil shape. Successively, the aforementioned processes are repeated to form the coil units U13 through U16, and thus the fourth loop element 36 is formed.
• the winding end of the coil unit U16 is drawn out at the outermost periphery side of the stator core 14 and connected to a neutral point of the rotary electric machine that is a junction between the coil unit rings 20 and 22 of V-phase and W-phase (FIG. 1).
• the winding end of the coil unit U16 is indicated by OUT (neutral point).
• the coil unit ring 18 of U-phase is described as above, the coil unit rings 20 and 22 of V-phase and W-phase are similarly constructed.
• the slots 12 in which the coil unit ring 20 of V-phase is placed are shifted by two slots in the circumferential direction
• the slots 12 in which the coil unit ring 22 of W-phase is placed are shifted by two more slots in the circumferential direction.
• each of the coil unit rings 18, 20, and 22 of respective phases may be a ring that includes at least one loop and that is constructed by arranging the coil unit Ul and then the coil unit U2, with the coil units 16 of the other phase interposed therebetween, and sequentially U3, U4, through U16 in the similar manner and connecting ends of the coil units of the same phase in an annular shape.
• an arrangement relation in the radial direction between the first loop element 30 and the fourth loop element 36 shown in FIG. 4 and an arrangement relation in the radial direction between the second loop element 32 and the third loop element 34 shown in FIG. 5 may be reversed.
• an arrangement order of the coil units 16 in the circumferential direction can be different from that of the example in the drawings.
• FIG. 6A and FIG. 6B are diagrams that show connection conditions including the slots 12 where the coil units Ul, U2 through U16 are placed in the stator core 14 depending on such a winding manner, and the reference numerals given to the 3 ⁇ 4 inner periphery of the stator core 14 correspond to the slot numbers SI, S2 through S48.
• FIG. 6 A corresponds to FIG. 4
• FIG. 6B corresponds to FIG. 5.
• Reference symbols P and Q in FIG. 6A and FIG. 6B denote that corresponding terminals Ps and Qs are connected respectively.
• Reference numerals in circles in FIG. 6A and FIG. 6B denote each turn of the coil units 16 by the same number.
• the coil units 16, of which two coil units are placed in one slot 12 are arranged so that the turns of the other coil unit 16 are alternately placed in the slot 12 with respect to the radial direction of the stator core 14 (hereinafter, in the case that merely "radial direction" is referred, it indicates the radial direction of the stator core 14).
• the turns of two coil units 16 that are placed in each slot 12 are placed so that plural turns of one coil unit 16 are arranged adjacently in the radial direction, and next to the turns in the radial direction, the other plural turns of one coil unit 16 are arranged adjacently in the radial direction.
• each coil unit 16 includes a one coil end portion 26 that is disposed on one end in the axial direction (upper end of FIG. 2) of the coil unit rings 18, 20, and 22 (FIG. 1).
• the one coil end portion 26 has: slot passing sections 38 and 40 that can pass two corresponding slots 12 in the axial direction when the placed-in-slot sections 24 that are provided at two end portions of each coil unit 16 in the width direction and inserted in plural corresponding slots 12 (FIG. 1) are inserted to fit the coil unit rings 18, 20, and 22 from one axial end side (lower end side of FIG. 1) of the stator core 14 (FIG.
• each connection 44 is provided to extend radially outward with respect to the stator core 14 at the other axial end side of the coil unit rings 18, 20, and 22 that protrude from the one axial end side of the stator core 14.
• the coil unit rings 18, 20, and 22 of plural phases, each formed of coil units 16, are fitted, as shown in FIG. 1, from one axial end side of the stator core 14 (lower side in FIG. 1) in the axial direction (to the upper side in FIG. 1) in the state where the coil unit rings 18, 20, and 22 are assembled into an annular shape.
• the one coil end portions 26 that are provided in the coil unit rings 18, 20, and 22 of respective phases pass through the slot 12 or are positioned on the radially inner side with respect to the inner periphery of the stator core 14, and therefore the fitting of the coil unit rings 18, 20, and 22 is not impeded.
• FIG. 1 the coil unit rings 18, 20, and 22 of plural phases, each formed of coil units 16, are fitted, as shown in FIG. 1, from one axial end side of the stator core 14 (lower side in FIG. 1) in the axial direction (to the upper side in FIG. 1) in the state where the coil unit rings 18, 20, and 22 are assembled into an annular shape.
• FIG. 7 is a circumferentially partial, schematic perspective view that shows a state where the coil unit 16 of the first loop element 30 of the coil unit ring 18 of U-phase in FIG. 3 is wound on the stator core 14.
• the coil units 16 are wound twice in the slot 12 for simplifying the illustration.
• Arrows in FIG. 7 show the direction of current flow at one moment.
• the slot passing sections 38 and 40 that are provided in the one coil end portion 26 align in the radial direction or the axial direction of the corresponding slots 12, and therefore the slot passing sections 38 and 40 can pass through the slots 12 in the axial direction during the fitting into the stator core 14.
• the connections 44 of two coil units 16 to be connected extend radially outward at a middle section in the circumferential direction between two coil units 16. As shown in FIG.
• input terminal lines 46u, 46v, and 46w that are provided in the coil unit rings 18 of respective phases extend radially outward with respect to the stator core 14.
• input terminals 48 that are provided at the ends of the input terminal lines 46u, 46v, and 46w are connected to output side terminals of respective phases of an inverter (not shown).
• FIG. 8 is a circumferentially partial, enlarged perspective view of FIG. 1, showing a partial cross section, that shows a state where parts of the coil units are placed in the slots.
• FIG 9A is a diagram that shows the stator in FIG. 8 in an extended state in the right and left circumferential direction in order to illustrate a first example, in which the dielectric constant of the coil unit that is inserted in a reference slot is made different from that of the coil unit that is inserted in an input terminal side slot.
• the stator 10 is constructed as described above, and therefore, as shown in FIG. 8 and FIG. 9A, the placed-in-slot sections 24 of the different coil units 16 are inserted in each slot 12 so as to align in the radial direction.
• FIG. 8 and FIG. 9A the placed-in-slot sections 24 of the different coil units 16 are inserted in each slot 12 so as to align in the radial direction.
• FIG 9A show the slots 12 of the aforementioned slot numbers S7 and S8.
• the placed-in-slot sections 24 of, of the coil units 16 that form the coil unit ring 18 of U-phase, the coil unit Ul of the first loop element 30 that is provided at the most input terminal side and the coil unit U16 of the fourth loop element 36 that is provided at the most neutral point side are inserted in the slot S7.
• the placed-in-slot sections 24 of, of the coil units 16 that form the coil unit ring 18 of U-phase, the coil unit U5 of the second loop element 32 and the coil unit U12 of the third loop element 34 are inserted in the slot S8.
• the placed-in-slot section 24 that is most likely to be applied with a high voltage when used is placed in the slot S7. That is, there is a possibility that the voltage due to the generation of surge voltage triggered by On-Off operation and the like of a switching element of the inverter is concentrated on the placed-in-slot section 24 in the slot S7 in which the coil unit Ul is disposed and thus the applied voltage may increase. Therefore, a potential difference between the adjacent coil units Ul and U16 in the slot S7 may increase. Furthermore, high voltage may be generated between the coil units Ul and U16 due to the effect of stray capacitance in the rotary electric machine.
• the coil unit Ul is also placed in the slot S13 that is not shown in FIG.
• the potential difference may similarly increase between the coil units Ul and U15 that are placed in the slot S13 (FIG. 4 and FIG. 6A).
• the aforementioned phenomenon may also occur in the coil units 16 of V-phase and W-phase. If the structure of the insulating layer that covers the surroundings of the placed-in-slot sections 24 of the coil units 16 that are placed in the slots 12 is not considered, in the case that the potential difference between the adjacent coil units 16 exceeds the partial discharge inception voltage (PDIV), an insulating section between the coil units 16 may be deteriorated by partial discharge.
• the present embodiment is devised as follows for the purpose of eliminating such disadvantages.
• the coil units 16 of respective phases include the coil unit Ul and the coil units U2 through U16 other than the coil unit Ul (hereinafter, described as "coil unit U5 etc.") as described above.
• the coil unit U5 etc. as a first coil has a first insulating layer 50 with a first dielectric constant ⁇ and covers around a conductor line 52 with the first insulating layer 50.
• the coil unit Ul as a second coil has a second insulating layer 54 with a second dielectric constant ⁇ 2 that is lower than the first dielectric constant ⁇ and covers around the conductor line 52 with the second insulating layer 54.
• the slots 12 include part of the slots, that is, slots S7 and S 13 that are the input terminal side slots in which the coil unit Ul is inserted (in the following description, referred to as the input terminal side slot S7) and the remaining slot S8 or the like (in the following description, referred to as the reference slot S8) that is a reference slot in which at least a part of the coil unit U5 is inserted.
• the coil unit Ul that is the input terminal side stator coil that is connected on the input terminal side with respect to the coil unit U5 etc. is inserted in the input terminal side slot S7.
• the coil units 16 that are inserted in the input terminal side slot S7, at least part of the coil units 16 includes the coil unit Ul that has the second insulating layer 54 of aforementioned low dielectric constant.
• the coil wire with its conductor line 52 covered with the second insulating layer 54 of low dielectric constant as described above is referred to as a "high PDIV line.”
• the second insulating layer 54 may include an enamel resin that has a resin, in which polyimide and polyamide-imide are alloyed with each other, and the first insulating layer 50 may include a material with the first dielectric constant ⁇ higher than the dielectric constant ⁇ 2 of the second insulating layer 54.
• the first insulating layer 50 may include an enamel resin that has polyamide-imide
• the second insulating layer 54 may include an enamel resin that has polyimide.
• the compositions of the first insulating layer 50 and the second insulating layer 54 are not limited to the above, and any materials can be used as long as there is a relation that the second dielectric constant ⁇ 2 of the second insulating layer 54 is lower than the first dielectric constant ⁇ of the first insulating layer 50.
• the first insulating layer 50 includes the enamel resin that has polyamide-imide
• any materials can be used for the second insulating layer 54 as long as the second insulating layer 54 has the second dielectric constant ⁇ 2 lower than the first dielectric constant ⁇ of the first insulating layer 50.
• the insulating layer with the relative dielectric constant ⁇ of 4 to 4.5 that is the first dielectric constant ⁇ is used as the first insulating layer 50
• the insulating layer with the relative dielectric constant ⁇ of about 3 to 3.5 that is the second dielectric constant ⁇ 2 can be used as the second insulating layer 54.
• the coil unit 16 that is a second coil having the second insulating layer 54 is the coil unit Ul only is described; however, plural coil units 16 that are, for example, the coil units U2, U3, and the like that are connected in the vicinity of the coil unit Ul may include the second insulating layer 54.
• the coil unit Ul that is the input terminal side stator coil that is connected on the input terminal side with respect to the coil unit U5 etc. as described above and the coil unit U16 (or U15) that is the neutral point side stator coil that is connected on the neutral point side with respect to the coil unit Ul are inserted in the input terminal side slot S7.
• the coil units 16 include the coil unit Ul and the coil unit U5 etc. that do not include the coil unit Ul, and the coil unit Ul has the second insulating layer 54 with the second dielectric constant ⁇ 2 lower than the first dielectric constant ⁇ of the first insulating layer 50 of the coil unit U5 etc.
• the slots 12 include the input terminal side slot S7 that is another than the reference slot S8 in which the coil unit U5 etc. are inserted and the coil unit Ul, which is the input terminal side stator coil that is connected on the input terminal side with respect to the coil unit U5 etc. is inserted in the input terminal side slot S7.
• the coil units 16 that are inserted in the input terminal side slot S7 at least part of the coil units 16 include the coil unit Ul, which is a second coil.
• the coil unit U16 (or U15)
• the partial discharge inception voltage between the coils Ul and U16 is sufficiently increased.
• the coil units 16 also include a number of the coil unit U5 etc. that include the first insulating layer 50 that has the first dielectric constant ⁇ higher than the second dielectric constant ⁇ 2, and therefore the cost does not increase excessively. Furthermore, there is no need to provide an insulating paper in the input terminal side slot S7 in order to increase the aforementioned partial discharge inception voltage. Therefore, even if part of the coil units 16 are inserted in the same slot 12, the partial discharge between the coil units 16 in the slot 12 can be suppressed more effectively. Although in FIG. 9 A, a gap is provided between the different coil units 16 in the slot 12, this gap may be made sufficiently small or eliminated.
• FIG. 9B is a diagram that corresponds to FIG. 9A in order to illustrate a first another example, in which the dielectric constant of the coil unit that is inserted in the reference slot is made different from that of the coil unit that is inserted in the input terminal side slot.
• the placed-in-slot section 24 of another coil unit U16 (or U15) is also placed in the input terminal side slot S7 in which the placed-in-slot section 24 of the coil unit Ul, which is a second coil, is placed.
• the coil unit U16 or U15 also has the second insulating layer 54 with the dielectric constant ⁇ 2 lower than the dielectric constant ⁇ of the first insulating layer 50.
• the partial discharge inception voltage between the coil unit Ul and the coil unit U16 or U15 can be sufficiently increased in the input terminal side slot S7, and therefore the partial discharge between the coil units 16 in the slot 12 is suppressed more effectively.
• the coil unit U16 or U15 may include a different insulating layer than the second insulating layer 54 as long as the coil unit U16 or U15 has the insulating layer with the lower dielectric constant than the dielectric constant ⁇ of the first insulating layer 50.
• FIG. 9C is a diagram that corresponds to FIG.
• the dielectric constant of the coil unit that is inserted in the reference slot is made different from that of the coil unit that is inserted in the input terminal side slot.
• the second insulating layer 54 is not provided in the coil unit Ul, and in the coil unit Ul, the coil wire is formed by covering the conductor line 52 with the first insulating layer 50 with a relatively higher dielectric constant.
• the coil unit U16 or U15 which is a second coil and is disposed in the input terminal side slot S7, in which the placed-in-slot section 24 of the coil unit Ul is placed, has the second insulating layer 54 with the second dielectric constant ⁇ 2 and the corresponding conductor line 52 is covered with the second insulating layer 54.
• the coil unit U16 or U15 is connected on the neutral point side with respect to the coil unit Ul.
• the coil unit U16 (or U15), which is a second coil, and the coil unit Ul, which is the input terminal side coil unit that is connected on the input terminal side with respect to the coil unit U5 etc., are inserted in the input terminal side slot S7.
• the coil unit Ul that is provided on the most input terminal side does not have the second insulating layer 54 with a low dielectric constant.
• the conductor line 52 is covered with the second insulating layer 54, the partial discharge inception voltage between the coil unit U16 or U15 and the input terminal side coil unit Ul is sufficiently increased in the input terminal side slot S7, and therefore the partial discharge between the coil units 16 in the slot 12 is suppressed more effectively.
• the stator 10A includes an annular stator core 14 that has a plurality of slots 12 at parts of an inner periphery in a circumferential direction, and segment ring sections 58, 60, and 62 of multiple phases that are U-phase, V-phase, and W-phase, the segment ring sections 58, 60, and 62 including coils wound on the stator core 14 by distributed winding.
• the structure of the stator core 14 is similar to that of the first embodiment described above.
• segment ring sections 58, 60, and 62 of respective phases are respectively formed such that conductor segment coils (hereinafter, merely referred to as “segment coils") 56 are connected in an annular shape and include a first loop element 64 (FIG. 15) and a second loop element 66 (FIG. 16) that are connected to each other.
• each segment coil 56 is formed by aligning plural conductor segments 68 of approximately U-shape shown in FIG. 11 and joining them into a coil shape.
• Each conductor segment 68 includes, at two end portions in the width direction (right and left direction in FIG. 11), two parallel legs 72 that have two placed-in-slot sections 70 that are respectively inserted in the slots 12 and a connecting section 74 that connects one ends of the legs 72.
• the stator 10A of the present embodiment is what is called a "segment coil winding type," and the segment ring sections 58, 60, and 62 of respective phases are formed by providing plural segment coils 56 (FIG. 10) in which a coil wire that is constituted of a conductor line covered with an insulating layer is formed in a coil shape and by connecting the segment coils 56 to form at least one loop (two loops in the case of the present embodiment) in the circumferential direction of the stator core 14.
• FIG. 10 parts with reference symbols "u”, "v”, and "w” indicate the U-phase, the V-phase, and the W-phase, respectively.
• FIG. 12 is a schematic perspective view that shows a manner in which the segment ring section 58 of one phase, U-phase, is wound on the stator core 14 in the stator 10A of FIG. 10.
• the segment ring sections 58, 60, and 62 of respective phases hereinafter, description is made of the segment ring section 58 of U-phase as a representative example
• eight segment coils 56 as unit coils each having a width of a predetermined unit coil spacing D2 (FIG.
• stator core 14 in the circumferential direction are wound on the stator core 14 so as to be connected in the annular shape to form one loop in the stator core 14 as a first loop element 64 and then, similar to the above manner, eight segment coils 56 are wound on the stator core 14 so as to be connected in the annular shape to form one loop in the stator core 14 as a second loop element 66, whereby the segment ring section 58 is constructed.
• the slots 12 in which the first loop element 64 is placed and the slots 12 in which the second loop element 66 is placed are shifted from each other by one slot in the circumferential direction.
• FIG. 13 is a diagram that shows the segment ring section 58 of U-phase that is removed from the rotary electric machine stator.
• a basic form of the segment ring sections 60 and 62 of V-phase and W-phase is similar to that of U-phase.
• the segment ring section 58 of U-phase is assembled from sixteen segment coils 56 as unit coils in which the coil wire is formed into the coil shape. Reference symbols CI, C2, through CI 6 that are indicated in FIG.
• a winding start of the segment ring section 58 of U-phase is a segment coil CI that is a first unit coil
• a winding end is a segment coil C16 that is a sixteenth unit coil.
• the segment coil C2 is placed adjacent to the segment coil CI, and sequentially the segment coils C3, C4 through C16 are placed in an adjacent manner to make two loops in the circumferential direction.
• the coil number is designated as "i”
• ith coil and (i+8)th coil are displaced from each other by one slot but placed such that the part of the coils overlap in the radial direction.
• FIG. 14 is a diagram that shows the first loop element 64 that is removed from the segment ring section 58 of FIG. 13.
• the first loop element 64 of the segment ring section 58 is formed by connecting eight segment coils 56 into an annular shape.
• Each segment coil 56 is formed of plural conductor segments 68.
• 9th through 16th segment coils 56 of the second loop element 66 are not illustrated; however, the basic form is the same as the shape of the first loop element 64 in FIG. 14, and placement position is displaced in the circumferential direction with respect to the first loop element 64.
• FIG. 15 is a schematic diagram that illustrates an arrangement manner in which the first loop element 64 of the segment ring section 58 of FIG. 13 is placed in the stator core 14.
• FIG. 16 is a schematic diagram that illustrates an arrangement manner in which the second loop element 66 of the segment ring section 58 of FIG. 13 is placed in the stator core 14. In FIG. 16, the first loop element 64 in FIG. 13 is not illustrated.
• FIG. 15 and FIG. 16 show a plan view of the stator core 14 and the segment coils 56 on the outside of the stator core 14.
• the segment coils 56 are wound on plural positions in the circumferential direction of the stator core 14 so as to span some of the slots 12 and to be inserted in two slots 12 that are separated from each other in the circumferential direction. These two slots 12 are spaced by the predetermined unit coil spacing D2.
• the segment coil CI is a winding start of the segment ring section 58 (FIG. 13) and connected to the input terminal side (IN side) that is a power line side of the rotary electric machine.
• the segment coil CI is formed in a coil shape by winding plural turns of the coil wire between the slots S4 and S10.
• the winding start is positioned in an outer periphery side of the stator core 14 that is the input terminal side and wound in the slots 12 in the coil shape so as to be directed from the outer periphery side to an inner periphery side.
• the segment coil CI is then connected to the segment coil C2 at the winding end. That is, the segment coil C2 is formed by extending the wire from the slot S10 at the winding end of the segment coil CI to the slot S16 that is spaced by the unit coil spacing D2 and winding plural turns of the coil wire between the slots S10 and S16 to form the coil shape. Successively, the aforementioned processes are repeated to form the segment coils CI through C8, and thus the first loop element 64 is formed.
• the winding end of the first loop element 64 is connected to the segment coil C9 of the second loop element 66 shown in FIG. 16 in the outermost periphery side of the stator core 14.
• the segment coil C9 is shifted by one slot from the segment coil CI and formed into the coil shape by winding plural turns of the coil wire between the slots S3 and S9.
• the segment coil C9 is then connected to the segment coil CIO at the winding end. That is, the segment coil CIO is formed by extending the wire from the slot S9 at the winding end of the segment coil C9 to the slot S15 that is spaced by the unit coil spacing D2 and winding plural turns of the coil wire between the slots S9 and S15 to form the coil shape. Successively, the aforementioned processes are repeated to form the segment coils C9 through C16, and thus the second loop element 66 is formed.
• the winding end of the segment coil CI 6 is drawn out of the outermost periphery side of the stator core 14 and connected to the neutral point of the rotary electric machine.
• the winding end of the segment coil C16 is indicated as OUT (neutral point).
• the slots 12 where the first loop element 64 and the second loop element 66 of the segment ring section 58 are placed are shifted in the circumferential direction.
• the segment ring section 58 of U-phase has been described above, the segment ring sections 60 and 62 of V-phase and W-phase are similarly constructed.
• the slots 12 where the segment ring section 60 of V-phase is placed are shifted by two slots in the circumferential direction
• the slots 12 where the segment ring section 62 of W-phase is placed are shifted by two more slots in the circumferential direction.
• each conductor segment 68 has two parallel legs 72 that are provided at the same spacing as the unit coil spacing D2 at both ends, and one ends of the legs 72 are connected by the connecting section 74.
• a tip end of one leg 72 of one conductor segment 68 and a tip end of the other side leg 72 of another conductor segment 68 that is adjacent to the aforementioned one conductor segment 68 in the radial direction are connected by welding or the like, and the above processes are repeated for each conductor segment 68.
• the segment coil 56 in a coil shape is formed.
• the segment coils 56 of respective phases include the segment coil CI and the segment coils C2 through CI 6 other than the segment coil CI (hereinafter, described as "segment coil C3 etc.") as described above.
• the segment coil C3 etc. which are first coils, each have a first insulating layer 50 (see FIG. 9A) with a first dielectric constant ⁇ and in the segment coil C3 etc., a conductor line is covered with the first insulating layer 50.
• the segment coil CI which is a second coil, has a second insulating layer 54 (see FIG. 9A) with a second dielectric constant ⁇ 2 that is lower than the first dielectric constant ⁇ and in the segment coil CI, the conductor line is covered with the second insulating layer 54.
• the slots 12 include slots S4 and SIO that are the input terminal side slots in which the segment coil CI is inserted (hereinafter, described as the input terminal side slot S4) and the remaining slot S16 etc. (hereinafter, described as the reference slot SI 6), which are reference slots in which at least part of the segment coil C3 etc. are inserted.
• the segment coil CI that is the input terminal side stator coil that is connected on the input terminal side with respect to the segment coil C3 etc. is inserted in the input terminal side slot S4.
• the segment coils 56 that are inserted in the input terminal side slot S4 at least part of the segment coils 56 include the segment coil CI that has the second insulating layer 54 with aforementioned low dielectric constant.
• the segment coils 56 include the segment coil CI and the segment coil C3 etc. other than the segment coil CI, and the segment coil CI has the second insulating layer 54 with the second dielectric constant ⁇ 2 lower than the first dielectric constant ⁇ of the first insulating layer 50 of the segment coil C3 etc.
• the slots 12 include the input terminal side slot S4 that is another than the reference slot S16 etc., in which the segment coil C3 etc. are inserted, and the segment coil CI, which is the input terminal side stator coil that is connected on the input terminal side with respect to the segment coil C3 etc. is inserted in the input terminal side slot S4.
• segment coils 56 that are inserted in the input terminal side slot S4
• at least part of the segment coils 56 include the segment coil CI.
• the segment coils 56 also include a number of the segment coil C3 etc. that include the first insulating layer 50 with the first dielectric constant ⁇ higher than the second dielectric constant ⁇ 2, and therefore the cost does not increase excessively. Furthermore, there is no need to provide an insulating paper in the input terminal side slot S4 in order to increase the aforementioned partial discharge inception voltage. Therefore, even if part of the segment coils 56 are inserted in the same slot 12, the partial discharge between the segment coils 56 in the slot 12 is suppressed more effectively.
• the second coil that has the second insulating layer 54 may include, in addition to the segment coil CI, one or more segment coils 56 that are the segment coil C2 etc. that are connected at a position(s) near the segment coil CI. Because each segment coil 56 is constructed by joining plural conductor segments 68, the dielectric constant of the insulating layer that constitutes part of the conductor segments 68 in the same segment coils 56 may be set lower than the dielectric constant of the insulating layer that constitutes the other conductor segments 68, to use the insulating layer with a lower dielectric constant between the parts in the same slot 12 only where the potential difference tends to occur in particular. In the present embodiment, similar to the case shown in FIG. 9B and FIG.
• part or all of at least part of the segment coils 56 among plural segment coils 56 that are placed in the input terminal side slot S4 may include the insulating layer with a relatively low dielectric constant.
• all segment coils 56 that are placed in the input terminal side S4 may include the insulating layer with a relatively lower dielectric constant than that of the insulating layer of the other segment coils 56 that are inserted in the reference slot S16 etc.
• Other structures and effects are similar to those of the first embodiment described above.
• At least part of the coil units 16 or the segment coils 56 that are inserted in part of the slots 12 that are input terminal side slots may be formed to include the second insulating layer 54 or another insulating layer that has the resin in which filler is mixed.
• the coil unit Ul may include the second insulating layer 54 that has the resin in which filler is mixed.
• the segment coil CI may include the second insulating layer 54 that has the resin in which filler is mixed.
• the insulating layer that is formed by mixing the filler may be provided not only to the coil that is disposed on the input terminal side but also to at least one or more other coils.
• the coil wire that has the insulating layer in which the filler is mixed in the resin as described above is called a "surge resistant wire".
• FIG. 17 shows diagrams that illustrate two examples of cases where a durability compensating method of the rotary electric machine is changed in response to changes in altitude and motor temperature in an embodiment according to the present invention.
• FIG. 17A shows how to change compensation of the durability of the stator between motor hardware compensation, namely the structure of the motor, and control compensation in response to the motor temperature that is the temperature of the rotary electric machine and the altitude.
• the motor hardware compensation means that the durability is compensated structurally other than controls of the rotary electric machine such as reduction of the drive voltage.
• the control compensation means that the durability is compensated through the controls of the rotary electric machine.
• the conventional motor hardware compensation took measures by providing the insulating paper to the part where high voltage is generated in the slot 12 (FIG. 1 and so on), for example.
• the first embodiment or the second embodiment described above it is possible to do without the insulating paper in the same motor hardware compensation region.
• control compensation region can be eliminated or made small as described above, there is no need to take measures using controls such as reducing the drive voltage so as to compensate the durability in a high-temperature environment or a high-altitude environment.
• performance improvement of the . rotary electric machine that includes the stator can be achieved, and improvement of dynamic performance of the vehicle such as an electric vehicle or a hybrid vehicle that uses the rotary electric machine as the drive motor can be achieved.
• stator coils of the concentric unit coil winding type and segment coil winding type have been described about the cases in which the present invention is applied to the stator coils of the concentric unit coil winding type and segment coil winding type; however, the present invention is not limited to those described above. While the case that the stator coil is wound on the stator core by distributed winding has been described above, the present invention can be carried out with a structure in which a plurality of stator coils are wound on the stator core by concentrated winding, for example.
• stator is not limited to the stator that constitutes a radial type rotary electric machine; the present invention can be carried out with a stator that is used in an axial type rotary electric machine, that is, a machine having a structure in which the stator and the rotor face each other in the axial direction.

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