Wound-field type rotary electric machine

Abstract

To reduce an eddy current loss in a first winding part to be at a stator side between the first winding part and a second winding part which constitute a field winding.SOLUTION: In a wound-field type rotary electric machine, a rotor 60 comprises a rotor core 61 including a main pole part 62, which is provided for each magnetic pole, and a field winding 70 which is wound around the main pole part 62. The field winding 70 includes a series connection body of a first winding part 71a and a second winding part 71b, and the winding parts 71a and 71b are wound around each main pole part 62 while positioning the first winding part 71a radially outside and positioning the second winding part 71b radially inside. The first winding part 71a is connected in series to a capacitor, thereby constituting a series resonance circuit. The second winding part 71b is connected in parallel to a capacitor, thereby constituting a parallel resonance circuit. Volume resistivity of a conductor material of the first winding part 71a is larger than volume resistivity of a conductor material of the second winding part 71b.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The disclosure in this specification relates to a wound field type rotating electric machine. [Background technology]

[0002] As an example of this type of wound field type rotating electric machine, a rotating electric machine described in Patent Document 1 is known. In this rotating electric machine, a field winding is wound around the main pole portion (magnetic salient pole portion) of each magnetic pole arranged in the circumferential direction of a rotor, and a field current is induced in the field winding by a harmonic current flowing through a winding (stator winding) of a stator arranged opposite the rotor. The field winding has a first winding portion and a second winding portion connected in series, and these winding portions are wound around the main pole portion with the first winding portion on the side closer to the stator and the second winding portion on the side farther from the stator in the radial direction, and a series resonant circuit is formed by the first winding portion and a capacitor, and a parallel resonant circuit is formed by the second winding portion and a capacitor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-54064 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the wound-field type rotating electric machine having the above configuration, the first winding is arranged on the side closer to the stator and the second winding is arranged on the side farther from the stator, so there is a concern that eddy current loss will occur in the first winding due to linkage of leakage flux of high-frequency excitation magnetic flux from the stator. If eddy current loss occurs in the first winding, the temperature of the first winding will become relatively high. Therefore, there is a concern that inconveniences such as limiting the current flowing through the first winding will occur.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a wound field type rotating electric machine that can reduce eddy current loss in the first winding portion, which is on the stator side, of the first and second winding portions that constitute the field winding. [Means for solving the problem]

[0006] The present disclosure relates to a stator having stator windings; a rotor having a rotor core having main pole portions provided for the magnetic poles arranged in the circumferential direction and projecting in the radial direction, and a field winding wound around the main pole portions, A wound-field type rotating electric machine in which a high-frequency current for inducing a field current in the field winding flows in the stator winding, the field winding has a first winding portion and a second winding portion connected in series, and the first winding portion is wound around each of the main pole portions in a radial direction such that the first winding portion is closer to the stator and the second winding portion is farther from the stator; the first winding portion is connected in series to a capacitor to form a series resonant circuit, and the second winding portion is connected in parallel to the capacitor to form a parallel resonant circuit, The volume resistivity of a conductive material of the first winding portion is greater than the volume resistivity of a conductive material of the second winding portion.

[0007] In a rotor of a wound-field type rotating electric machine, a configuration is conceivable in which a first winding section and a second winding section are connected in series as a field winding, and a series resonant circuit and a parallel resonant circuit are formed by each of these winding sections and a capacitor, and the first winding section is arranged on the side closer to the stator and the second winding section is arranged on the side farther from the stator in the radial direction. In this case, there is a concern that eddy current loss will occur in the first winding section, which is closer to the stator, due to linkage of leakage flux of high-frequency excitation magnetic flux from the stator. In consideration of this point, the volume resistivity of the conductor material of the first winding section is made larger than the volume resistivity of the conductor material of the second winding section. This makes it possible to reduce the effect of leakage flux in the first winding section. As a result, it is possible to reduce eddy current loss in the first winding section, which is on the stator side of the first and second winding sections that constitute the field winding. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an overall configuration diagram of a control system for a rotating electric machine. [Diagram 2] FIG. 2 is a diagram showing an inverter and its peripheral configuration. [Diagram 3] FIG. [Figure 4] FIG. 4 is a diagram showing an electric circuit provided in the rotor. [Diagram 5] FIG. 2 is a perspective view showing the overall configuration of a rotor. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 4 is an exploded perspective view of a winding unit in the rotor main portion. [Figure 9] FIG. [Figure 10] FIG. 3 is a cross-sectional view showing a schematic diagram of each conductive wire of a first winding portion and a second winding portion. [Figure 11] FIG. 4 is a schematic diagram showing a state in which windings are wound around each main pole of a rotor core. [Figure 12] FIG. 4 is a perspective view showing a configuration regarding connections of coil bodies in each winding portion. [Figure 13] Rotor electrical circuit diagram. [Figure 14] Cross-sectional view of a conductor. [Figure 15] FIG. 4 is a vertical cross-sectional view showing a state in which the conductor ends of the coil body are joined together in the part holder. [Figure 16] FIG. 3 is a cross-sectional view showing a schematic diagram of each conductive wire of a first winding portion and a second winding portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotating electric machine according to an embodiment of the present disclosure will now be described with reference to the drawings.

[0010] First, a control system including a rotating electric machine will be described with reference to Fig. 1. The control system includes a DC power supply 10, an inverter 20, a control device 30, and a rotating electric machine 40. The rotating electric machine 40 is a wound-field type synchronous machine. For example, the rotating electric machine 40, the inverter 20, and the control device 30 may be configured as a mechanically and electrically integrated drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 may each be configured with a respective component.

[0011] The rotating electric machine 40 includes a housing 41, and a stator 50 and a rotor 60 housed in the housing 41. The rotating electric machine 40 of this embodiment is an inner rotor type rotating electric machine in which the rotor 60 is disposed radially inside the stator 50. The stator 50 includes a stator core 51 and a stator winding 52. The stator winding 52 is made of, for example, copper wire, and includes U-, V-, and W-phase windings 52U, 52V, and 52W disposed with an electrical angle of 120° from each other. The rotor 60 includes a rotor core 61 and a field winding 70. A rotating shaft 32 is assembled in a central hole of the rotor core 61. The rotating shaft 32 is rotatably supported by the housing 41 by bearings 42 and 43.

[0012] As shown in FIG. 2, the inverter 20 includes a series connection of upper arm switches SUp, SVp, SWp of U, V, and W phases and lower arm switches SUn, SVn, SWn of U, V, and W phases. First ends of U, V, and W phase windings 52U, 52V, and 52W are connected to the connection points of the upper arm switches SUp, SVp, and SWp and the lower arm switches SUn, SVn, and SWn in each phase. Second ends of the U, V, and W phase windings 52U, 52V, and 52W are connected at the neutral point. That is, in this embodiment, the stator winding 52 is star-connected. However, the stator winding 52 may be delta-connected. In this embodiment, each switch SUp to SWn is an IGBT. A freewheel diode is connected in inverse parallel to each switch SUp to SWn.

[0013] The collectors of the upper arm switches SUp, SVp, SWp of each phase are connected to the positive terminal of the DC power supply 10. The emitters of the lower arm switches SUn, SVn, SWn of each phase are connected to the negative terminal of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0014] Next, the stator 50 and the rotor 60 will be described with reference to FIG.

[0015] The stator 50 and the rotor 60 are both arranged coaxially with the rotating shaft 32. In the following description, the direction in which the rotating shaft 32 extends is referred to as the axial direction, the direction extending radially from the center of the rotating shaft 32 is referred to as the radial direction, and the direction extending circumferentially around the rotating shaft 32 is referred to as the circumferential direction.

[0016] The stator core 51 is made of laminated steel plates made of soft magnetic material, and has an annular back yoke 51a and a plurality of teeth 51b protruding radially inward from the back yoke 51a. A plurality of slots 54 are formed between adjacent teeth 51b arranged in the circumferential direction. The stator winding 52 is formed by accommodating the phase windings of each phase in a predetermined order in each of these slots 54. For example, the stator 50 may have a segment coil structure using a plurality of conductor segments. However, the structure of the stator winding 52 is arbitrary.

[0017] The rotor core 61 is made of a soft magnetic material, for example, laminated steel plates. The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 protruding radially outward from the cylindrical portion 61a. A field winding 70 is wound around the main pole portions 62 by concentrated winding. In this embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction.

[0018] The field winding 70 includes a first winding portion 71a and a second winding portion 71b. The first winding portion 71a is wound on the radially outer side of each main pole portion 62, and the second winding portion 71b is wound on the radially inner side of the first winding portion 71a. In terms of the relationship with the stator 50, the first winding portion 71a is wound on the side closer to the stator 50 in the radial direction, and the second winding portion 71b is wound on the side farther from the stator 50. In each main pole portion 62, the winding directions of the first winding portion 71a and the second winding portion 71b are the same. In addition, among the main pole portions 62 adjacent in the circumferential direction, the winding directions of the winding portions 71a and 71b wound on one side are opposite to the winding directions of the winding portions 71a and 71b wound on the other side. Therefore, the magnetization directions of the main pole portions 62 adjacent in the circumferential direction are opposite to each other. In the rotor 60, the main pole portions 62 of the rotor core 61 and the field windings 70 wound around the main pole portions 62 form a plurality of magnetic poles (field poles) arranged in the circumferential direction.

[0019] 4 shows an electric circuit on the rotor 60 side including the winding parts 71a, 71b wound around the main pole part 62. The first winding part 71a and the second winding part 71b are connected in series, and a capacitor part CC consisting of a plurality of first capacitors 91 is connected in parallel to the second winding part 71b. The capacitor part CC is configured as a parallel connection of a plurality of first capacitors 91. A second capacitor 92 is connected in parallel to the series connection of the first winding part 71a and the second winding part 71b. The second capacitor 92 is provided for noise suppression. The first capacitor 91 and the second capacitor 92 are, for example, multilayer ceramic capacitors and have the same configuration.

[0020] A diode 93 is connected as a rectifying element between both ends of the series-connected body consisting of the windings 71a and 71b. That is, a first end of the first winding 71a is connected to the cathode of the diode 93, and a first end of the second winding 71b is connected to the second end of the first winding 71a. An anode of the diode 93 is connected to the second end of the second winding 71b.

[0021] In this embodiment, the first winding portion 71a, the first capacitor 91, and the diode 93 form a series resonant circuit, and the second winding portion 71b and the first capacitor 91 form a parallel resonant circuit. In this case, the first winding portion 71a is connected in series to the first capacitor 91, and the second winding portion 71b is connected in parallel to the first capacitor 91. If the first resonant frequency, which is the resonant frequency of the series resonant circuit, is f1 and the second resonant frequency, which is the resonant frequency of the parallel resonant circuit, is f2, these resonant frequencies f1 and f2 are expressed by the following formulas (1) and (2). L1 is the inductance of the first winding portion 71a, L2 is the inductance of the second winding portion 71b, and C is the capacitance of the first capacitor 91. f1=1 / (2π√(L1×C)) …(1) f2=1 / (2π√(L2×C)) …(2) When a high-frequency excitation current flows through the stator winding 52, a fluctuation occurs in the magnetic circuit including the stator core 51 and the rotor core 61 due to the high-frequency component of the main magnetic flux. The fluctuation in the main magnetic flux generates an induced voltage in each of the winding parts 71a, 71b, and a current is induced in each of the winding parts 71a, 71b. At this time, if an induced voltage of the same polarity occurs in each of the winding parts 71a, 71b, the induced currents in the winding parts 71a, 71b are not offset, and the induced current increases. The current flowing through each of the winding parts 71a, 71b is rectified in one direction by the diode 93. As a result, a field current flows through the field winding 70 in the direction rectified by the diode 93, and the field winding 70 is excited.

[0022] Returning to the explanation of Fig. 2, the control device 30 is mainly configured with a microcomputer (corresponding to a computer), and the microcomputer has a CPU. The control device 30 generates drive signals that turn on and off each of the switches SUp to SWn that configure the inverter 20. In detail, the control device 30 generates drive signals that turn on and off each of the switches SUp to SWn in order to convert the DC power output from the DC power source 10 into AC power and supply it to the U-, V-, and W-phase windings 52U, 52V, and 52W, and supplies the generated drive signals to the gates of each of the switches SUp to SWn.

[0023] The control device 30 turns on and off each of the switches SUp to SWn so that a composite current of a fundamental current and a high-frequency excitation current flows through each of the phase windings 52U, 52V, 52W. The fundamental current is a current that mainly generates torque in the rotating electric machine 40. The high-frequency excitation current is a high-frequency current with a higher frequency than the fundamental current, and is a current that mainly excites the field winding 70. It is also possible to use a harmonic current as the high-frequency current. The phase currents flowing through the phase windings 52U, 52V, 52W are shifted by 120° in electrical angle.

[0024] Next, a more detailed description will be given of the configuration of the rotor 60. Fig. 5 is a perspective view showing the overall configuration of the rotor 60, Fig. 6 is an exploded perspective view of the rotor 60, and Fig. 7 is a vertical cross-sectional view of the rotor 60.

[0025] The rotor 60 is broadly divided into a rotor main part 101, a circuit module 102 provided at one of both axial ends of the rotor main part 101, and coil end covers 103, 104 as circular members attached to one and the other axial ends of the rotor main part 101. The rotor main part 101 includes the rotor core 61 and the field winding 70 as described in Fig. 3, and the rotating shaft 32 is attached to the central hole of the rotor core 61. The field winding 70 is made up of a plurality of winding units 110 arranged in a line in the circumferential direction.

[0026] The circuit module 102 is fixed to the rotating shaft 32 with the rotating shaft 32 inserted into the hollow portion. The circuit module 102 is provided at a position axially facing the coil end portion of the field winding 70. The circuit module 102 is an electric circuit section including the capacitors 91, 92 and diode 93 described in Fig. 4, as well as bus bars that electrically connect these elements.

[0027] Fig. 8 is an exploded perspective view of the winding unit 110 in the rotor main part 101, and Fig. 9 is a cross-sectional view showing the cross-sectional structure of a portion of the rotor main part 101. The rotor main part 101 has a plurality of winding units 110 provided for each magnetic pole of the rotor 60. Each winding unit 110 is formed in an annular shape with the axial direction as the longitudinal direction, and is assembled to the rotor core 61 with the main pole part 62 of the rotor core 61 inserted into the hollow part.

[0028] The winding unit 110 has a first coil module 111 that is radially outward and a second coil module 112 that is radially inward when attached to the main pole portion 62. The first coil module 111 is a coil module that corresponds to the first winding portion 71a, and the second coil module 112 is a coil module that corresponds to the second winding portion 71b.

[0029] The first coil module 111 has an annular coil body 121 formed by multiple windings of a conductive wire made of a rectangular wire in the circumferential and radial directions of the rotor 60, and a thin plate-like insulator 122 provided integrally with the coil body 121. The insulator 122 has a portion that extends in the circumferential direction and covers the radially outer and inner sides of the coil body 121, and a portion that extends in the radial direction and covers the hollow part of the coil body 121. In other words, the coil body 121 is insulated and coated with the insulator 122 at the radially inner and outer parts and at the inner peripheral part facing the main pole 62.

[0030] The second coil module 112 has an annular coil body 123 formed by multiple windings of a conductive wire made of a rectangular wire in the circumferential and radial directions of the rotor 60, and a thin plate-like insulator 124 provided integrally with the coil body 123. The insulator 124 has a portion that extends in the circumferential direction and covers the radially outer and inner sides of the coil body 123, and a portion that extends in the radial direction and covers the hollow part of the coil body 123. In other words, the coil body 123 is insulated and coated with the insulator 124 at the radially inner and outer parts and at the inner peripheral part facing the main pole 62.

[0031] The coil bodies 121, 123 are configured as, for example, α-wound coils, and are air-core coils in which the conductor material is wound in multiple layers in the overlapping direction (rotor circumferential direction) and in two layers in the extending direction of the hollow part (rotor radial direction). In this embodiment, a rectangular conductor wire with a conductor cross section having long and short sides is used as the conductor material of the coil bodies 121, 123. The coil bodies 121, 123 are wound in a direction in which the long side parts overlap in multiple layers due to the turns of the conductor material. The rectangular wire is composed of a conductor made of aluminum or the like and an insulating layer covering the conductor.

[0032] In the first coil module 111, two conductor ends 125 are drawn out in the axial direction from one coil body 121. In the second coil module 112, a total of six conductor ends 126 are drawn out in the axial direction from three coil bodies 123 arranged radially.

[0033] As shown in FIG. 9, in the first coil module 111, the conductor is wound in two layers in the radial direction, and in the second coil module 112, the conductor is wound in six layers in the radial direction. As for the coil bodies 121 and 123, in the first coil module 111, one coil body 121 is provided in the radial direction, and in the second coil module 112, three coil bodies 123 are provided side by side in the radial direction. In this case, the number of turns of the second winding portion 71b in each main pole portion 62 is greater than the number of turns of the first winding portion 71a. Note that in each coil module 111 and 112, the number of turns in the circumferential direction (in other words, the number of rows of the conductor in the circumferential direction) is different, and the number of turns is greater on the radially outer side than on the radially inner side. This improves the space factor of the field winding 70.

[0034] Furthermore, holding plates 127, 128 are provided between the main pole portions 62 of the rotor core 61 in the rotor main section 101 to hold the first coil module 111 and the second coil module 112 in an assembled state when the first coil module 111 and the second coil module 112 are assembled to the main pole portions 62. The holding plate 127 is attached to the radial outside of the first coil module 111, and the holding plate 128 is attached between the first coil module 111 and the second coil module 112.

[0035] As shown in Fig. 6, the rotor 60 has a coil end ring 81 that is attached to an axial end of the winding unit 110. As shown in Fig. 7, the coil end ring 81 is disposed between the coil end portion of the first coil module 111 and the coil end portion of the second coil module 112 in the radial direction, and is sandwiched between the retaining plate 128 and the coil end cover 103 in the axial direction.

[0036] In the present embodiment, in the rotor 60 of the wound field type, the windings 71a and 71b of the field winding 70 and the first capacitor 91 form a series resonant circuit and a parallel resonant circuit, and the number of turns of the second winding 71b on the radially inner side is greater than the number of turns of the first winding 71a on the radially outer side. In this case, by making the number of turns of the second winding 71b greater than that of the first winding 71a, the inductance of the second winding 71b increases, and the field current can be increased. Here, in the configuration in which the number of turns of the second winding 71b is greater than that of the first winding 71a, the current value (effective current value) of the second winding 71b becomes smaller than the current value of the first winding 71a. In other words, the current that can be passed through the second winding 71b only needs to be smaller than that of the first winding 71a.

[0037] In consideration of this point, in this embodiment, the conductor cross-sectional area of ​​the conductor wire used in the second winding portion 71b is made smaller than the conductor cross-sectional area of ​​the conductor wire used in the first winding portion 71a. Below, characteristics of the winding structure of the field winding 70 will be described.

[0038] Fig. 10 is a cross-sectional view showing the conductor wires C1, C2 of the first winding portion 71a and the second winding portion 71b. Fig. 10 shows one each of the coil body 121 of the first winding portion 71a and the coil body 123 of the second winding portion 71b wound around the main pole portion 62, with the up-down direction in the figure being the radial direction and the left-right direction in the figure being the circumferential direction.

[0039] As shown in FIG. 10, the conductor wire C1 of the coil body 121 (first winding portion 71a) and the conductor wire C2 of the coil body 123 (second winding portion 71b) have different cross-sectional areas, i.e., conductor cross-sectional areas, and the conductor cross-sectional area of ​​the conductor wire C2 is smaller than that of the conductor wire C1. More specifically, when the length dimensions of the long side and short side of the conductor wire C1 are D1 and D2, and the length dimensions of the long side and short side of the conductor wire C2 are D3 and D4, the relationship of these length dimensions is D1=D3 and D2>D4. In other words, the conductor wire C2 has the same length dimension of the long side and a smaller length dimension of the short side than that of the conductor wire C1. In this case, it is possible to increase the number of turns in the second winding portion 71b compared to the case where conductor wires with the same conductor cross-sectional area are used in the first winding portion 71a and the second winding portion 71b.

[0040] 9, in the rotor core 61, the space between the circumferentially adjacent main pole portions 62 is a winding space for the conductor wire, and when viewed in the radial direction, the winding space is relatively narrower on the radially inner side. In this regard, since the conductor cross-sectional area of ​​the conductor wire C2 of the second winding portion 71b is smaller than the conductor cross-sectional area of ​​the conductor wire C1 of the first winding portion 71a, the number of turns of the conductor wire C2 can be ensured even in the relatively narrow winding space.

[0041] FIG. 11 is a schematic diagram showing a state in which each winding portion 71a, 71b is wound around each main pole portion 62 of the rotor core 61. In FIG. 11, two conductor layers on the radially outer side are defined as the first winding portion 71a, and four conductor layers on the radially inner side are defined as the second winding portion 71b. The first winding portion 71a is configured by assembling coil bodies 121 to each of the main pole portions 62 arranged in the circumferential direction, and connecting the coil bodies 121 in series. Here, the coil bodies 121 constituting the first winding portion 71a are sequentially designated C11, C12, C13, ... C18 in the clockwise direction, and the coil bodies C11 to C18 are connected in series with each other adjacent to each other in the circumferential direction to form the first winding portion 71a.

[0042] The second winding portion 71b is configured by assembling two coil bodies 123 to each of the main pole parts 62 arranged in the circumferential direction, and connecting the coil bodies 123 in series. Here, the coil bodies 123 of the second winding portion 71b adjacent to the first winding portion 71a are sequentially designated as C21, C22, C23, ... C28, and the coil bodies 123 radially inside are sequentially designated as C31, C32, C33, ... C38. The second winding portion 71b is configured by connecting one end of the series-connected body of the coil bodies C21 to C28 to one end of the series-connected body of the coil bodies C31 to C38. In FIG. 11, for convenience of explanation, two coil bodies 123 are assembled to each main pole part 62, but the same applies when three or more coil bodies are assembled to each main pole part 62.

[0043] Fig. 12 is a perspective view showing a configuration relating to the connection of the coil bodies 121, 123 in each winding portion 71a, 71b in the rotor 60. Fig. 12 shows a state in which the circuit module 102 is assembled to one axial side of the rotor main portion 101.

[0044] The circuit module 102 includes a component holder 130 that holds the above-mentioned capacitors 91, 92 and diode 93. The component holder 130 is made of an electrically insulating material such as synthetic resin. The component holder 130 includes a main body 131 that has an annular shape, and a plurality of conductor fixing portions 132 that extend radially outward from the main body 131 in the radial direction. Although not shown in FIG. 12 because it is covered by the resin molded portion 105, the main body 131 has the capacitors 91, 92 and diode 93 arranged in a line at positions that form an annular shape surrounding the rotating shaft 32.

[0045] The component holder 130 is provided with eight conductor wire fixing portions 132, the same number as the main pole portions 62. Each conductor wire fixing portion 132 is formed with a plurality of insertion holes 133 penetrating in the axial direction. Conductor wire ends 125, 126 extending from the coil bodies 121, 123 of each winding portion 71a, 71b are inserted into each of these insertion holes 133, and the conductor wire ends 125, 126 inserted into the conductor wire ends 125, 126 are joined to each other by welding or the like.

[0046] Of the eight conductor wire fixing portions 132, three conductor wire fixing portions 132A, 132B, and 132C shown in FIG. 12 will be described in detail.

[0047] In the conductor fixing portion 132A, the coil bodies 121, 123 arranged in four rows in the radial direction are connected to each other in the same row. Specifically, in the conductor fixing portion 132A, in the connection portion X1, the conductor ends 125 of the coil bodies 121 adjacent in the circumferential direction are inserted into the insertion holes 133 one by one, and the conductor ends 125 are connected to each other. In addition, in the connection portions X2 to X4, the conductor ends 126 of the coil bodies 123 adjacent in the circumferential direction are inserted into the insertion holes 133 one by one, and the conductor ends 126 are connected to each other. In the connection portion X5, bus bars 141, 142 for connection to the first capacitor 91 are connected.

[0048] At the connection parts X1 to X4, i.e., the portions where the conductor ends 125 or 126 of the coil bodies 121 and 123 are connected to each other, the coil bodies 121 and 123 are connected by welding or the like with the long sides of the conductor material, which is a rectangular wire, joined to each other. In this case, a larger joint surface can be secured compared to a configuration in which the short sides of the conductor material are joined to each other. Therefore, an appropriate connection can be achieved in terms of both strength and conductivity.

[0049] In the conductor fixing portion 132A, the conductor ends 126 of the coil bodies 123 are connected to each other at three connection portions X2 to X4. That is, in the second winding portion 71b, the conductor ends 126 are connected to each other at the same number of points as the number of coil bodies 123 arranged in the circumferential direction. Here, if the conductor cross-sectional area of ​​the conductor material C2 of the coil body 123 is made smaller than that of the conductor material C1 of the coil body 121, and the radial width dimension of the conductor material C2 in the second winding portion 71b is made smaller than that of the conductor material C1, the number of coil bodies 123 arranged in the radial direction increases, and the number of connection points connecting the coil bodies 123 to each other increases. In this regard, in the present embodiment, the circumferential width dimension of the conductor material C2 is made smaller than that of the conductor material C1 as a configuration for reducing the cross-sectional area of ​​the conductor material C2, so that the number of coil bodies 123 arranged in the radial direction does not increase. This suppresses a decrease in workability due to an increase in the number of connection points between the coil bodies 123.

[0050] On the other hand, in the conductor fixing portion 132B, the coil bodies 121, 123 in each row are connected to each other in different rows (lane change connection) and to each of the capacitors 91, 92 and the diode 93 via a bus bar. Specifically, in the conductor fixing portion 132B, at a connection portion Y1, the conductor end portion 125 of the coil body 121 of the first winding portion 71a, one end of the bus bar 143 for the second capacitor 92, and an end of the bus bar 144 for connecting the cathode of the diode 93 are connected. The connection at this connection portion Y1 corresponds to the connection at the connection point A1 in the circuit diagram of FIG. 13. Also, at a connection portion Y2, the conductor end portion 125 of the coil body 121 of the first winding portion 71a, the conductor end portion 126 of the coil body 123 of the second winding portion 71b, and an end of the bus bar 142 for the first capacitor 91 are connected. The connection at the connection point Y2 corresponds to the connection at the connection point A2 in the circuit diagram of FIG.

[0051] At the connection portion Y2, the conductor ends 125, 126 of the coil bodies 121, 123 are connected in a state where the conductor materials C1, C2 (see FIG. 10) having different conductor cross-sectional areas are joined together. Specifically, the conductor materials C1, C2 of the coil bodies 121, 123 are connected by welding or the like in a state where their long sides are joined together. In this case, although the conductor materials C1, C2 of the coil bodies 121, 123 have different conductor cross-sectional areas, the conductor material C2 of the coil body 123 has the same length dimension of the long side as the conductor material C1 of the coil body 121, and therefore a sufficient joint surface between them can be secured.

[0052] At the connection points Y3 and Y4, the conductor ends 126 of the coil bodies 123 in different rows are connected to each other. At the connection point Y5, bus bars 143 and 145 for connection to the second capacitor 92 are connected.

[0053] In conductor fixing portion 132C, at connection point Z1, conductor end portion 126 of coil body 123 of second winding portion 71b, an end of bus bar 146 common to capacitors 91, 92, and an end of bus bar 147 for connecting the anode of diode 93 are connected. The connection at connection point Z1 corresponds to the connection at connection point A3 in the circuit diagram of FIG.

[0054] At least one of the conductor wires C1, C2 of the first winding portion 71a and the second winding portion 71b may be a bundled wire (divided wire) formed by bundling a plurality of wires.

[0055] Specifically, as shown in FIG. 14(a), the conductor C1 is composed of a plurality of wires 151 and an outer covering portion 152 that covers each of the wires 151 from the outer periphery. As shown in FIG. 14(b), the conductor C2 is composed of a plurality of wires 151 and an outer covering portion 152 that covers each of the wires 151 from the outer periphery. The conductors C1 and C2 are both composed of the same wires 151, but have different cross sections due to the difference in the number of wires 151. The wires 151 may be coated conductors having a conductor and an insulating covering that covers the conductor. The conductors C1 and C2 may be composed of different wires 151 from each other. For example, the cross section of the wires 151 of the conductor C1 may be larger than the cross section of the wires 151 of the conductor C2. The wires 151 are rectangular in cross section, but may be round. The conductive wires C1 and C2 may be a stranded wire in which a plurality of wires 151 are twisted together.

[0056] In the rotating electric machine 40, a high-frequency current corresponding to the excitation frequency flows through the field winding 70 of the rotor 60, and therefore each of the winding portions 71a, 71b is likely to be affected by the skin effect. In this regard, by making the conductor wires C1, C2 of each of the winding portions 71a, 71b into a bundled wire in which a plurality of strands 151 are bundled, that is, a divided wire in which the conductor cross section is divided into a plurality of parts, the influence of the skin effect in each of the winding portions 71a, 71b can be reduced.

[0057] Furthermore, in the field winding 70, the first winding portion 71a on the radially outer side is closer to the stator 50, and the second winding portion 71b on the radially inner side is farther from the stator 50, and there is a concern that eddy current loss will occur in the first winding portion 71a due to linkage of leakage flux of high-frequency excitation magnetic flux from the stator 50. As a countermeasure, it is advisable to make the volume resistivity of the conductor material of the first winding portion 71a larger than the volume resistivity of the conductor material of the second winding portion 71b.

[0058] Specifically, for example, the conductor material of the first winding portion 71a (coil body 121) is aluminum, and the conductor material of the second winding portion 71b (coil body 123) is copper. It is also possible to use CNT (carbon nanotube) as the conductor material of the first winding portion 71a and copper as the conductor material of the second winding portion 71b. This reduces the influence of leakage flux in the first winding portion 71a, making it possible to reduce eddy current loss. In addition, the wire materials of the winding portions 71a and 71b are different from each other, and the second winding portion 71b, which is relatively less influenced by leakage flux, is made of a material with low electrical resistance, so that a decrease in current in the second winding portion 71b is suppressed.

[0059] When the first winding portion 71a is made of aluminum wire and the second winding portion 71b is made of copper wire, the conductor material of the first winding portion 71a has a higher volume resistivity and a lower specific gravity than the conductor material of the second winding portion 71b. This makes it possible to reduce eddy current loss caused by leakage flux from the stator 50 in the first winding portion 71a on the radial outside (stator 50 side) as well as to reduce centrifugal force during rotor rotation.

[0060] If the first winding portion 71a and the second winding portion 71b are made of different materials, there is a concern that galvanic corrosion may occur due to moisture adhering to the joints between them. In view of this, it is preferable that the joints between the conductive wires in the first winding portion 71a and the second winding portion 71b are covered with an insulating material.

[0061] 15 is a vertical cross-sectional view showing a state in which the conductor end 125 of the coil body 121 and the conductor end 126 of the coil body 123 are joined in the component holder 130 of the circuit module 102. In FIG. 15, the conductor ends 125, 126 of the coil bodies 121, 123 are inserted into the insertion holes 133 in the conductor fixing part 132 of the component holder 130, and are joined at their tip sides by welding or the like. A resin coating part 161 made of a resin material such as epoxy resin is formed so as to cover the joint part of the conductor ends 125, 126. The resin coating part 161 is preferably provided so as to cover the entire joint part of the conductor ends 125, 126, and a part of it is provided in a state in which it fits into the insertion hole 133 of the conductor fixing part 132. Resin coating portion 161 suppresses galvanic corrosion at the joint between first winding portion 71a and second winding portion 71b even if they are made of different materials.

[0062] In addition, the resin coating portion 161 may be provided not only at the joint between the conductor end 125 of the coil body 121 and the conductor end 126 of the coil body 123, but also at other joints, i.e., the joint between the conductor ends 125 of the coil body 121 and the joint between the conductor ends 126 of the coil body 123.

[0063] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0064] In the field winding 70, the volume resistivity of the conductor material of the first winding portion 71a is set to be greater than the volume resistivity of the conductor material of the second winding portion 71b. This reduces the effect of leakage flux in the first winding portion 71a. As a result, it is possible to reduce eddy current loss in the first winding portion 71a, which is on the stator 50 side of the winding portions 71a and 71b constituting the field winding 70.

[0065] In the field winding 70, the conductor material of the first winding portion 71a has a higher volume resistivity and a lower specific gravity than the conductor material of the second winding portion 71b. In other words, a high-resistance, lightweight material that is relatively high-resistance and lightweight is used as the conductor material of the first winding portion 71a on the radially outer side. This reduces eddy current loss in the first winding portion 71a and reduces the centrifugal force during rotor rotation.

[0066] In the rotating electric machine 40, a high-frequency current corresponding to the excitation frequency flows through the field winding 70 of the rotor 60, and therefore each of the winding portions 71a, 71b may be affected by the skin effect. In this regard, by using bundled wire as the conductor material for each of the winding portions 71a, 71b, the influence of the skin effect in each of the winding portions 71a, 71b can be reduced, and further loss suppression can be achieved.

[0067] If the first winding portion 71a and the second winding portion 71b of the field winding 70 are made of different materials, there is a concern that galvanic corrosion may occur due to moisture adhering to the joints. In consideration of this, the joints between the conductive wires in the first winding portion 71a and the second winding portion 71b are covered with an insulating material. This makes it possible to suppress galvanic corrosion at the joints even if the first winding portion 71a and the second winding portion 71b are made of different materials.

[0068] (Other embodiments) The above embodiment may be modified, for example, as follows.

[0069] Only one of the conductor wires C1, C2 of each of the winding portions 71a, 71b may be a bundled wire, or neither of the conductor wires C1, C2 may be a bundled wire.

[0070] FIG. 16 shows a configuration in which the conductor wire C1 of the first winding portion 71a is a bundled wire, and the conductor wire C2 of the second winding portion 71b is a solid wire instead of a bundled wire. In this case, the effect of reducing overcurrent loss can be enhanced in the first winding portion 71a, which is susceptible to leakage flux of high-frequency excitation magnetic flux from the stator 50. On the other hand, bundled wires are more likely to have variations in outer diameter dimensions than solid wires, and if the second winding portion 71b wound around the radially inner portion of the main pole portion 62 is a bundled wire, there is a concern that the winding of the conductor wire will be hindered due to dimensional variations in a relatively narrow space. In this regard, by making the second winding portion 71b a solid wire instead of a bundled wire, it is possible to suppress the occurrence of problems in the winding of the conductor wire.

[0071] In the above embodiment, the conductor cross-sectional area of ​​the conductor wire C2 of the second winding portion 71b is made smaller than the conductor cross-sectional area of ​​the conductor wire C1 of the first winding portion 71a by making the length dimension of the long side of the conductor wire C2 the same as that of the conductor wire C1 and making the length dimension of the short side smaller (see FIG. 10). However, this may be changed. For example, the conductor wire C2 may be configured so that the length dimension of the short side of the conductor wire C2 is the same as that of the conductor wire C1 and the length dimension of the long side is smaller. Or, the conductor wire C2 may be configured so that the length dimensions of the long side and the short side are smaller than those of the conductor wire C1.

[0072] In the above embodiment, the conductor material of each of the winding parts 71a, 71b is rectangular wire, but this may be changed. For example, the conductor material of one of the winding parts 71a, 71b may be rectangular wire and the conductor material of the other may be round wire. Alternatively, both conductor materials may be round wire.

[0073] In the above embodiment, the conductor ends of the coil bodies 121, 123 in each of the winding portions 71a, 71b are joined together by welding. However, this may be modified so that the conductor ends are joined together by crimping or bolting.

[0074] The winding portions 71a, 71b may be made of the same conductive material. Specifically, the conductive material of the winding portions 71a, 71b may be, for example, aluminum, copper, or CNT.

[0075] The rotating electric machine is not limited to an inner rotor type rotating electric machine, and may be an outer rotor type rotating electric machine. In an outer rotor type rotating electric machine, the stator 50 is disposed radially inward, and the rotor 60 is disposed radially outward. In this case, the main pole portion 62 protrudes radially inward from the annular yoke portion of the rotor core. In the field winding 70, the first winding portion 71a is preferably disposed radially inward (on the stator 50 side), and the second winding portion 71b is preferably disposed radially outward (opposite the stator side).

[0076] In the stator 50, the stator core may be a teeth-threaded core that does not have teeth.

[0077] The rotating electric machine is not limited to a rotating electric machine used as an in-vehicle main engine, but may be, for example, a rotating electric machine used as an ISG (Integrated Starter Generator) that serves as both a motor and a generator.

[0078] The moving object on which the rotating electric machine system is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. Furthermore, the rotating electric machine system is not limited to a system mounted on a moving object, but may be a stationary system.

[0079] The technical ideas extracted from the above-described embodiments will be described below. [Configuration 1] a stator (50) having a stator winding (52); a rotor (60) having a rotor core (61) having main pole portions (62) provided for each of the magnetic poles arranged in the circumferential direction and projecting in the radial direction, and a field winding (70) wound around the main pole portions, A wound-field type rotating electric machine (40) in which a high-frequency current for inducing a field current in the field winding flows in the stator winding, the field winding has a first winding portion (71a) and a second winding portion (71b) connected in series, and the first winding portion is wound around each of the main pole portions in a radial direction such that the first winding portion is closer to the stator and the second winding portion is farther from the stator; the first winding portion is connected in series to a capacitor (91) to form a series resonant circuit, and the second winding portion is connected in parallel to the capacitor to form a parallel resonant circuit, a volume resistivity of a conductor material of the first winding portion being greater than a volume resistivity of a conductor material of the second winding portion; [Configuration 2] a wound-field type rotating electric machine having an inner rotor structure in which the stator is disposed radially outside and the rotor is disposed radially inside, 2. The wound field type rotating electric machine according to configuration 1, wherein a conductor material of the first winding portion has a smaller specific gravity than a conductor material of the second winding portion. [Configuration 3] 3. The wound-field type rotating electric machine according to configuration 1 or 2, wherein the conductor material of at least one of the first winding portion and the second winding portion is a bundled wire formed by bundling a plurality of strands. [Configuration 4] a wound-field type rotating electric machine having an inner rotor structure in which the stator is disposed radially outside and the rotor is disposed radially inside, 3. The wound field type rotating electric machine according to configuration 1 or 2, wherein the conductor material of the first winding portion is a bundled wire formed by bundling a plurality of wires, and the conductor material of the second winding portion is not the bundled wire. [Configuration 5] the first winding portion and the second winding portion are electrically connected to each other by joining the respective conductive wires to each other, 5. The wound-field type rotating electric machine according to any one of configurations 1 to 4, wherein a joint between the conductive wires in the first winding portion and the second winding portion is covered with an insulating material. [Explanation of symbols]

[0080] 40... rotating electric machine, 50... stator, 52... stator winding, 60... rotor, 61... rotor core, 62... main pole portion, 70... field winding, 71a... first winding portion, 71b... second winding portion.

Claims

1. a stator (50) having stator windings (52); a rotor (60) having a rotor core (61) having main pole portions (62) provided for each magnetic pole arranged in the circumferential direction and protruding in the radial direction, and a field winding (70) wound around the main pole portions, A wound-field rotating electric machine (40) in which a high-frequency current for inducing a field current in the field winding flows through the stator winding, The field winding has a series connection of a first winding portion (71 a) and a second winding portion (71 b), and these winding portions are wound around the main pole portions with the first winding portion on the side closer to the stator and the second winding portion on the side farther from the stator in the radial direction, a volume resistivity of the conductor material of the first winding portion being greater than a volume resistivity of the conductor material of the second winding portion;

2. a wound-field rotating electric machine having an inner rotor structure in which the stator is disposed radially outward and the rotor is disposed radially inward, 2. The wound-field rotating electric machine according to claim 1, wherein the conductive material of said first winding portion has a specific gravity smaller than that of the conductive material of said second winding portion.

3. 3. The wound-field rotating electric machine according to claim 1, wherein the conductor material of at least one of the first winding portion and the second winding portion is a bundled wire formed by bundling a plurality of wires.

4. a wound-field rotating electric machine having an inner rotor structure in which the stator is disposed radially outward and the rotor is disposed radially inward, 3. The wound-field rotating electric machine according to claim 1, wherein the conductor material of said first winding portion is a bundled wire formed by bundling a plurality of wires, and the conductor material of said second winding portion is not said bundled wire.

5. the first winding portion and the second winding portion are electrically connected by joining the respective conductive wires to each other, 3. The wound-field rotating electric machine according to claim 1, wherein a joint between the conductors in said first winding portion and said second winding portion is covered with an insulating material.

6. A wound field type rotating electric motor as described in claim 1 or 2, wherein the second winding section has a greater number of turns than the first winding section.

7. A wound field type rotating electric motor as described in claim 1 or 2, wherein the conductor cross-sectional area of ​​the wire material used in the second winding section is smaller than that of the wire material used in the first winding section.

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