JP2014176114A - Excitation type rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excitation type rotary electric machine capable of preventing output torque from being reduced when a coil temperature rises.SOLUTION: The excitation type rotary electric machine comprises: a rotor including first and second rotor cores which are disposed while axially opposing each other with an interval interposed therebetween in an axial direction; a plurality of first magnetic poles disposed in the first rotor core at predetermined intervals in a circumferential direction; a plurality of second magnetic poles disposed in the second rotor core at predetermined intervals in a circumferential direction and with a phase opposite to that of the first magnetic poles; a stator which is disposed at an outer diameter side of the rotor oppositely in a radial direction via an air gap, and has a stator coil to generate a rotational magnetic field for rotating the rotor; an excitation coil for exciting the first magnetic poles and the second magnetic poles; and a control device in which, when a temperature of one of the excitation coil and the stator coil is higher than a predetermined threshold value, the amount of electrification to one coil is decreased and the amount of electrification to the other coil is increased.

Description

  The present disclosure relates to an excitation-type rotating electrical machine.

  Conventionally, a rotor having first and second rotor cores arranged to face each other with a gap in the axial direction, and a stator that is arranged to face the outer diameter side of the rotor via an air gap and generates a rotating magnetic field that rotates the rotor. Is known (for example, see Patent Document 1).

  The stator has a stator core in which stator teeth protruding toward the axis center are provided at predetermined intervals in the circumferential direction. For example, a three-phase stator coil is wound around each stator tooth. When the stator coil of each phase is energized at an appropriate timing, a rotating magnetic field that rotates the rotor is generated.

  In addition, each of the pair of rotor cores is alternately arranged in the circumferential direction at the radial end, and a permanent magnet excitation magnetic pole excited by a permanent magnet, and a non-excitation permanent magnet non-excitation magnetic pole not excited by the permanent magnet, ,have. The permanent magnet exciting magnetic pole and the permanent magnet non-exciting magnetic pole are each arranged at a predetermined interval in the circumferential direction. The permanent magnet exciting magnetic pole of the first rotor core and the permanent magnet exciting magnetic pole of the second rotor core have opposite polarities. The permanent magnet excitation magnetic pole of the first rotor core and the permanent magnet non-excitation magnetic pole of the second rotor core are arranged to face each other with a gap in the axial direction, and the permanent magnet non-excitation magnetic pole of the first rotor core and the second rotor core The permanent magnet exciting magnetic poles are arranged to face each other with a gap in the axial direction. That is, the permanent magnet non-excited magnetic pole of the first rotor core and the permanent magnet non-excited magnetic pole of the second rotor core are arranged opposite to each other while being offset in the circumferential direction.

  The excitation-type rotating electrical machine includes an excitation coil that excites permanent magnet non-excitation magnetic poles. The amount of magnetic flux by the permanent magnet is substantially constant. When the exciting coil is energized, a magnetic flux is generated that weakens or strengthens the magnetic flux generated by the permanent magnet by exciting the non-excited magnetic pole of the permanent magnet. Therefore, according to the above-described excitation-type rotating electrical machine, the rotor can be appropriately rotated by the combined magnetic flux of the magnetic flux by the permanent magnet and the magnetic flux by the electromagnet using the exciting coil.

  Further, the temperature measured directly by the temperature measuring means with the temperature of the field winding is compared with a preset allowable temperature based on the burning temperature of the field winding determined in advance through experiments or the like, and the measured temperature is A control device for a synchronous generator that controls current supplied from an automatic voltage regulator to a field winding so as not to exceed an allowable temperature is known (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 08-251891 JP 2006-345584 A

  By the way, as described in Patent Document 2 described above, it is desirable that the energization amount of the coil is controlled so that the coil temperature does not exceed a predetermined upper limit value.

  In this regard, in the excitation-type rotating electrical machine as described in Patent Document 1, it is necessary to monitor the temperatures of both the stator coil and the excitation coil. At this time, for example, in the configuration in which the torque limit is activated when the coil temperature (the temperature of the stator coil or the temperature of the excitation coil) increases, there is a problem that the output torque of the excitation-type rotating electrical machine decreases when the torque limit is activated.

  Therefore, an object of the present disclosure is to provide an excitation-type rotating electrical machine that can suppress a decrease in output torque when the coil temperature increases.

According to one aspect of the present disclosure, a rotor having first and second rotor cores arranged to face each other in the axial direction with a gap in the axial direction;
A plurality of first magnetic poles arranged at predetermined intervals in the circumferential direction on the first rotor core;
A plurality of second magnetic poles disposed at a predetermined interval in the circumferential direction in the second rotor core and disposed in a phase opposite to the first magnetic pole;
A stator that is radially opposed to the outer diameter side of the rotor via an air gap, and has a stator coil that generates a rotating magnetic field that rotates the rotor;
An exciting coil for exciting the first magnetic pole and the second magnetic pole;
An excitation device including a controller that reduces an energization amount to the one coil and increases an energization amount to the other coil when the temperature of one of the excitation coil and the stator coil is higher than a predetermined threshold value. A rotating electric machine is provided.

  According to the present disclosure, an excitation-type rotating electrical machine that can suppress a decrease in output torque when the coil temperature increases can be obtained.

It is a perspective view showing the structure of the excitation type rotary electric machine 10 by one Example. It is sectional drawing at the time of cut | disconnecting the excitation type rotary electric machine 10 by one Example in the plane containing an axial centerline. It is sectional drawing at the time of cut | disconnecting the excitation type rotary electric machine 10 by one Example by III-III shown in FIG. It is sectional drawing when the excitation type rotary electric machine 10 by one Example is cut | disconnected by IV-IV shown in FIG. It is a block block diagram of the control apparatus 100 of the excitation type rotary electric machine 10 of a present Example. It is a block block diagram of the torque control part 116 of the control apparatus 100 of the excitation type rotary electric machine 10 of a present Example. 5 is a flowchart showing an example of processing executed by a torque control unit 116. It is a figure which shows the time-sequential waveform which shows an example of the restriction | limiting of a torque command value, and a relationship between stator coil temperature and exciting coil temperature. It is a figure which shows the time-sequential waveform which shows an example of the relationship between excitation current command value Idr * and a three-phase coil current command value, stator coil temperature, and excitation coil temperature. FIG. 9 is a diagram showing a time-series waveform according to a comparative example as a comparison with FIG. 8. 7 is a flowchart illustrating an example of processing of a torque limiting unit 145. 4 is a block diagram illustrating an example of an excitation current correction unit 144. FIG.

  Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing the structure of an excitation-type rotating electrical machine 10 according to one embodiment. FIG. 1 shows an excitation-type rotating electrical machine 10 with a part cut. FIG. 2 is a cross-sectional view of the excitation-type rotating electrical machine 10 according to the present embodiment cut along a plane including the axis center line. FIG. 3 shows a cross-sectional view of the excitation-type rotating electrical machine 10 of the present embodiment taken along the line III-III shown in FIG. FIG. 4 shows a cross-sectional view of the excitation-type rotating electrical machine 10 of the present embodiment taken along IV-IV shown in FIG.

  In this embodiment, the excitation-type rotating electrical machine 10 adjusts the torque for rotating the rotor around the stator by the combined magnetic flux of the magnetic flux by the permanent magnet and the magnetic flux by the electromagnet using the exciting coil, and appropriately rotates the rotor. It is a hybrid excitation type rotating electrical machine that can be used. The excitation-type rotating electrical machine 10 may be applied to, for example, an AC motor for driving a vehicle used in a hybrid vehicle or an electric vehicle, but may be used for any other purpose. .

  The excitation-type rotating electrical machine 10 includes a rotor 12 that can rotate around an axis, and a stator 14 that generates a rotating magnetic field that rotates the rotor 12. The rotor 12 is rotatably supported by the case 20 via bearings 16 and 18 at both axial ends. The stator 14 is disposed on the outer diameter side of the rotor 12 and is fixed to the case 20. The rotor 12 and the stator 14 oppose each other via an air gap 22 having a predetermined length in the radial direction.

  The stator 14 has a stator core 24 and a stator coil 28. The stator core 24 is formed in a hollow cylindrical shape. A stator tooth 26 is formed on the inner peripheral surface of the stator core 24. The stator teeth 26 protrude inward in the radial direction of the stator core 24, that is, toward the axial center. A plurality of stator teeth 26 (for example, 12 or 18) are provided in the circumferential direction on the inner circumferential surface of the stator core 24, and are provided at equal intervals along the circumferential direction.

  A status lot 27 is formed between the stator teeth 26 adjacent in the circumferential direction. That is, stator teeth 26 and status lots 27 are alternately formed on the stator core 24 in the circumferential direction. A stator coil 28 is wound around each stator tooth 26. That is, the stator coil 28 is wound around each stator tooth 26. A plurality of stator coils 28 (for example, 12 or 18) are provided in the circumferential direction on the inner circumferential surface of the stator core 24, and are provided at equal intervals along the circumferential direction. Each stator coil 28 constitutes one of a U-phase coil, a V-phase coil, and a W-phase coil when the excitation-type rotating electrical machine 10 is applied to, for example, a three-phase AC motor.

  The stator core 24 is divided in the axial direction, and includes a first stator core 30, a second stator core 32, and a third stator core 34. The first to third stator cores 30 to 34 are each formed in a hollow cylindrical shape and are arranged in the axial direction. The first and third stator cores 30 and 34 are disposed at both ends in the axial direction. The second stator core 32 is disposed at the center in the axial direction. The second stator core 32 is sandwiched between the first stator core 30 and the third stator core 34 in the axial direction, and is fixed to the end surfaces near the center in the axial direction of the first and third stator cores 30 and 34 by adhesion or the like.

  The first to third stator cores 30 to 34 have substantially the same inner diameter and the same outer diameter. Each of the first to third stator cores 30 to 34 has an annular back yoke portion and a stator tooth portion that protrudes from the inner peripheral surface of the back yoke portion constituting the stator tooth 26 toward the axial center. And consist of In each of the first to third stator cores 30 to 34, the back yoke portion and the stator teeth portion may be formed integrally with each other, but may be provided separately from each other. The stator coil 28 is formed so as to penetrate the first to third stator cores 30 to 34 in the axial direction in the status lot 27 between the stator teeth 26 aligned in the circumferential direction.

  Each of the first and third stator cores 30 and 34 is a magnetic steel sheet core formed by laminating a plurality of insulating coated steel sheets in the axial direction. The second stator core 32 is a dust core formed of a soft magnetic material such as iron, specifically, a material obtained by compression-molding a soft magnetic powder coated with an insulating coating. The magnetic resistance in the axial direction of the second stator core 32 is smaller than the magnetic resistance in the axial direction of the first and third stator cores 30 and 34.

  A thin cylindrical yoke 36 is provided on the outer diameter side of the stator core 24. The yoke 36 is formed so as to cover the entire outer circumference of the first to third stator cores 30 to 34, and supports the first to third stator cores 30 to 34. Like the second stator core 32, the yoke 36 is a dust core formed of a material obtained by compression-molding an insulating-coated soft magnetic powder. The magnetic resistance in the axial direction of the yoke 36 is smaller than the magnetic resistance in the axial direction of the first and third stator cores 30 and 34. The yoke 36 and the second stator core 32 may be formed integrally with each other. The yoke 36 is bonded and fixed to the outer diameter surfaces of the first stator core 30 and the third stator core 34. The first stator core 30 and the third stator core 34 are magnetically coupled to each other via the yoke 36 and the second stator core 32.

  The stator core 24 has an attachment portion 38 that protrudes to the outer diameter side for attaching and fixing the stator 14 to the case 20. The attachment portion 38 is formed of a plurality of electromagnetic steel plates laminated in the axial direction. The attachment portion 38 includes an attachment portion 38a formed integrally with the first stator core 30, an attachment portion 38b formed integrally with the third stator core 34, and an attachment portion 38c sandwiched between both attachment portions 38a, 38b. Have. The attachment portion 38 c is disposed on the outer diameter side of the second stator core 32. Note that the attachment portion 38c may be formed integrally with the second stator core 32 instead of being formed by a plurality of electromagnetic steel plates laminated in the axial direction. A plurality of (for example, three) mounting portions 38 are provided in the circumferential direction. The attachment portion 38 is provided with a through hole 40 penetrating in the axial direction. The stator 14 is fixed to the case 20 by fastening a bolt 42 that passes through the through hole 40 of the attachment portion 38 to the case 20.

  The rotor 12 is disposed on the inner diameter side of the stator 14. The rotor 12 includes a shaft 50 and a rotor core 52. The shaft 50 extends in the axial direction, and extends from the axial end of the stator 14 at both axial ends. The shaft 50 only needs to extend from the axial end of the stator 14 at least on one side in the axial direction. The shaft 50 is made of a material having a predetermined iron loss, specifically, carbon steel such as S45C. The rotor core 52 has an outer diameter side rotor core 54 that is disposed on the outer diameter side of the shaft 50 and supported by the shaft 50. The outer diameter side rotor core 54 is formed in a hollow cylindrical shape, and is fixed to the outer diameter surface of the shaft 50.

  The outer diameter side rotor core 54 is divided in the axial direction, and includes a first outer diameter side rotor core 56 and a second outer diameter side rotor core 58. The first and second outer diameter side rotor cores 56 and 58 are each formed in a hollow cylindrical shape, and are disposed on the outer diameter side of the shaft 50 and supported by the shaft 50. The first and second outer-diameter-side rotor cores 56 and 58 are each formed by laminating a plurality of insulating coated steel sheets in the axial direction. The first outer diameter side rotor core 56 and the second outer diameter side rotor core 58 are separated from each other with an annular gap 60 in the axial direction. The gap 60 is formed to have substantially the same size (width) from the inner diameter side portion to the outer diameter side portion of the first and second outer diameter side rotor cores 56 and 58.

  The outer diameter surface of the first outer diameter side rotor core 56 faces the inner diameter surface of the first stator core 30 in the radial direction. That is, the outer diameter surface of the first outer diameter side rotor core 56 and the inner diameter surface of the first stator core 30 are opposed to each other in the radial direction. Further, the outer diameter surface of the second outer diameter side rotor core 58 faces the inner diameter surface of the third stator core 34 in the radial direction. That is, the outer diameter surface of the second outer diameter side rotor core 58 and the inner diameter surface of the third stator core 34 are opposed to each other in the radial direction. The gap 60 faces the inner diameter surface of the second stator core 32 and is provided on the inner diameter side of the second stator core 32.

  A rotor tooth 62 is formed on the outer periphery of the first outer diameter side rotor core 56. The rotor teeth 62 protrude outward in the radial direction of the first outer diameter side rotor core 56. A plurality of (for example, six) rotor teeth 62 are provided in the circumferential direction on the outer peripheral surface of the first outer diameter side rotor core 56, and are provided at equal intervals along the circumferential direction.

  Permanent magnets 64 are attached between the rotor teeth 62 adjacent to each other in the circumferential direction so as to be adjacent to the rotor teeth 62. The permanent magnet 64 is disposed on the outer diameter side of the first outer diameter side rotor core 56. The permanent magnet 64 is, for example, a ferrite magnet. A plurality of permanent magnets 64 (for example, six) are provided in the circumferential direction, and are provided at regular intervals along the circumferential direction. Each permanent magnet 64 has a predetermined width (angle) in the circumferential direction and a predetermined thickness in the radial direction. Each permanent magnet 64 is magnetized to a predetermined polarity (for example, the outer diameter side is an N pole and the inner diameter side is an S pole).

  The outer diameter side end surface of the permanent magnet 64 and the outer diameter side end surface of the rotor teeth 62 are formed at substantially the same distance from the axis center. The outer diameter side end surface of the permanent magnet 64 may be positioned slightly radially inward from the outer diameter side end surface of the rotor teeth 62. The first outer diameter side rotor core 56 has a permanent magnet excitation magnetic pole excited by the permanent magnet 64 and a non-excitation permanent magnet non-excitation magnetic pole that is not excited by the permanent magnet 64. This permanent magnet non-excitation magnetic pole is formed in the rotor teeth 62. These permanent magnet excitation magnetic poles and permanent magnet non-excitation magnetic poles are alternately arranged in the circumferential direction. The first outer diameter side rotor core 56 has magnetic poles having different polarities at every predetermined angle, and has a predetermined number (for example, 12) of poles in the circumferential direction by permanent magnet excitation magnetic poles and permanent magnet non-excitation magnetic poles. ing.

  A rotor tooth 66 is formed on the outer periphery of the second outer diameter side rotor core 58. The rotor teeth 66 protrude outward in the radial direction of the second outer diameter side rotor core 58. A plurality of (for example, six) rotor teeth 66 are provided in the circumferential direction on the outer peripheral surface of the second outer diameter side rotor core 58, and are provided at equal intervals along the circumferential direction.

  Permanent magnets 68 are attached adjacent to the rotor teeth 66 between the rotor teeth 66 adjacent to each other in the circumferential direction. The permanent magnet 68 is disposed on the outer diameter side of the second outer diameter side rotor core 58. The permanent magnet 68 is, for example, a ferrite magnet. A plurality (for example, six) of permanent magnets 68 are provided in the circumferential direction, and are provided at regular intervals along the circumferential direction. Each permanent magnet 68 has a predetermined width (angle) in the circumferential direction and a predetermined thickness in the radial direction. Each permanent magnet 68 is magnetized to a predetermined polarity (for example, the outer diameter side is an S pole and the inner diameter side is an N pole) different from the polarity of the permanent magnet 64. That is, the permanent magnet 68 and the permanent magnet 64 have opposite polarities.

  The outer diameter side end surface of the permanent magnet 68 and the outer diameter side end surface of the rotor teeth 66 are formed at positions that are substantially the same distance from the center of the shaft. The outer diameter side end face of the permanent magnet 68 may be positioned slightly radially inward from the outer diameter side end face of the rotor teeth 66. The second outer diameter side rotor core 58 has a permanent magnet excitation magnetic pole excited by the permanent magnet 68 and a non-excitation permanent magnet non-excitation magnetic pole that is not excited by the permanent magnet 68. This permanent magnet non-excitation magnetic pole is formed in the rotor tooth 66. These permanent magnet excitation magnetic poles and permanent magnet non-excitation magnetic poles are alternately arranged in the circumferential direction. The second outer diameter side rotor core 58 has magnetic poles having different polarities for each predetermined angle, and has the same number of poles as the first outer diameter side rotor core 56 in the circumferential direction by the permanent magnet excitation magnetic pole and the permanent magnet non-excitation magnetic pole. It has a number (for example, 12) of poles.

  The permanent magnet exciting magnetic pole of the first outer diameter side rotor core 56 and the permanent magnet non-exciting magnetic pole of the second outer diameter side rotor core 58 are arranged to face each other through the gap 60 in the axial direction. That is, the permanent magnet 64 of the first outer diameter side rotor core 56 and the rotor teeth 66 of the second outer diameter side rotor core 58 are arranged to face each other via the gap 60 in the axial direction. Further, the permanent magnet non-excitation magnetic pole of the first outer diameter side rotor core 56 and the permanent magnet excitation magnetic pole of the second outer diameter side rotor core 58 are arranged to face each other via the gap 60 in the axial direction. That is, the rotor teeth 62 of the first outer diameter side rotor core 56 and the permanent magnets 68 of the second outer diameter side rotor core 58 are arranged to face each other via the gap 60 in the axial direction. The permanent magnet exciting magnetic poles of the first and second outer diameter side rotor cores 56, 58 are arranged in opposite phases in the circumferential direction, and the permanent magnet non-exciting magnetic poles are arranged in opposite phases in the circumferential direction. Has been.

  In the gap 60, that is, between the first outer diameter side rotor core 56 and the second outer diameter side rotor core 58, there is an exciting coil 70 for exciting the permanent magnet non-exciting magnetic poles of the rotor teeth 62, 66. Has been placed. The exciting coil 70 is made of an electric wire such as a copper wire and fills almost the entire area of the gap 60. The exciting coil 70 is formed in an annular shape around the shaft 50 and is toroidally wound. The exciting coil 70 is formed so that the axial thickness in each part in the radial direction is substantially uniform. The exciting coil 70 is disposed on the outer diameter side of the shaft 50 and is disposed on the inner diameter side of the second stator core 32, and faces the second stator core 32 in the radial direction.

  The exciting coil 70 is fixed to the stator 14 (specifically, the second stator core 32 of the stator core 24). The excitation coil 70 is fixed to the stator 14 using a holding member 71. The holding member 71 is a clip member made of a resin or the like formed in a U-shaped cross section or a U-shaped cross section so that the annular excitation coil 70 can be held from the inner diameter side, and in the circumferential direction around the shaft 50. A plurality are provided.

  As a method for fixing the exciting coil 70 to the stator 14, the exciting coil 70 may be directly fixed to the first to third stator cores 30 to 34, for example, the first stator core 30 and the third stator core 34. The exciting coil 70 may be fixed to the stator 14 by making a hole in the axial end face facing each other or the inner diameter face of the second stator core 32 and hooking the holding member 71 through the hole.

  As shown in FIG. 1, the lead wire 77 of the exciting coil 70 passes through the slot between the stator teeth 26 of the stator core 24 of the stator 14 so as to pass through in the axial direction. And connected to a control device 100 described later. A direct current is supplied to the exciting coil 70 via a control device 100 from a direct current power source (for example, a vehicle-mounted battery). When a direct current is supplied to the exciting coil 70, a magnetic flux that penetrates the inner diameter side (axial center side) of the exciting coil 70 in the axial direction is generated. This amount of magnetic flux has a magnitude corresponding to the direct current supplied to the exciting coil 70.

  The shaft 50 is formed in a hollow shape. The shaft 50 includes a large diameter cylindrical portion 72 having a relatively large diameter and small diameter cylindrical portions 74 and 76 having a relatively small diameter. The small diameter cylindrical portions 74 and 76 are provided at both axial ends. The large-diameter cylindrical portion 72 is provided at the center in the axial direction, and is sandwiched between small-diameter cylindrical portions 74 and 76 at both ends in the axial direction. The shaft 50 is supported by the case 20 via the bearings 16 and 18 in the small diameter cylindrical portions 74 and 76. The first and second outer-diameter-side rotor cores 56 and 58 are disposed on the outer-diameter side of the large-diameter cylindrical portion 72 and supported by the large-diameter cylindrical portion 72, and are arranged on the outer-diameter surface of the large-diameter cylindrical portion 72. It is fixed.

  The rotor core 52 has an inner diameter side rotor core 80 that is disposed on the inner diameter side of the shaft 50 and supported by the shaft 50. The inner diameter side rotor core 80 is disposed on the inner diameter side of the first outer diameter side rotor core 56 and the second outer diameter side rotor core 58 of the rotor core 52 and on the inner diameter side of the exciting coil 70. A hollow space 82 is formed in the large-diameter cylindrical portion 72 of the shaft 50. The inner diameter side rotor core 80 is accommodated in the hollow space 82 of the large diameter cylindrical portion 72, and is bonded and fixed to the inner diameter surface of the large diameter cylindrical portion 72. The inner diameter side rotor core 80 is formed of a soft magnetic material, specifically, a material obtained by compression molding a soft magnetic powder coated with an insulating coating. The inner diameter side rotor core 80 is formed of a material whose iron loss is smaller than that of the shaft 50.

  The inner diameter side rotor core 80 is divided in the circumferential direction, and includes a plurality of (for example, six) rotor core pieces 84 formed in a fan shape when viewed from the axial direction. The division in the circumferential direction of the inner diameter side rotor core 80 is performed at equal intervals (equal angles) in the circumferential direction, and the respective rotor core pieces 84 have the same shape. The number of divisions in the circumferential direction of the inner diameter side rotor core 80, that is, the number of rotor core pieces 84 is the number of poles of the first and second outer diameter side rotor cores 56, 58 in the outer diameter side rotor core 54 or a divisor of the number of poles. For example, when the number of poles is “12”, the number of divisions is “2”, “3”, “4”, “6”, or “12” (in FIG. 3 and FIG. 4, the number of divisions is “6”. ”).

  The division in the circumferential direction of the inner diameter side rotor core 80 is also performed by permanent magnets 64 alternately arranged in the circumferential direction in the axial centers of the rotor 12 and the shaft 50 and the first and second outer diameter side rotor cores 56 and 58 of the rotor 12. , 68 and the rotor teeth 62, 66 (that is, the permanent magnet excitation magnetic pole and the permanent magnet non-excitation magnetic pole) are performed on a line passing through the circumferential center of each of two or more of them. That is, each plane including the dividing surface in the circumferential direction of the inner diameter side rotor core 80 passes through the axial center of the rotor 12 or the shaft 50, and any of the permanent magnets 64 and 68 and the rotor teeth 62 and 66 (that is, the permanent magnets). Passes through the center in the circumferential direction of the excitation magnetic pole and permanent magnet non-excitation magnetic pole).

  Further, the inner diameter side rotor core 80 has notch holes 86 and 88 that are vacant in the axial direction at the axial end portion. The notches 86 and 88 are provided at both ends in the axial direction. The cutout holes 86 and 88 are formed in a tapered shape or a stepped shape so that the diameter decreases from the axial end surface to the axial center. The diameters of the axial end portions (the shallowest portion) of the cutout holes 86 and 88 substantially coincide with the inner diameter of the large-diameter cylindrical portion 72 of the shaft 50, and the axial center portions (the deepest portion) of the cutout holes 86 and 88. The diameter is a predetermined diameter. The inner diameter side rotor core 80 has a predetermined thickness in the radial direction at the axially central portion, and has a thickness smaller than the thickness of the axially central portion at each axial end portion. The radial thickness of the large-diameter cylindrical portion 72 of the shaft 50 is set to a thickness that maintains the strength necessary for transmitting the motor torque, and the radial thickness at the axial central portion of the inner diameter side rotor core 80. Is set to a predetermined thickness that does not saturate the magnetic flux generated by the exciting coil 70, the radial thickness at the axially central portion of the inner diameter side rotor core 80 is the radial thickness of the large diameter cylindrical portion 72 of the shaft 50. Greater than thickness.

  The cutout hole 86 and the cutout hole 88 communicate with each other on the axial center side, and are connected through a through hole 89 that penetrates the deepest portions in the axial direction. That is, the inner diameter side rotor core 80 is formed in a hollow shape so that the through hole 89 is formed. The cutout holes 86 and 88 and the through hole 89 of the inner diameter side rotor core 80 are all provided on the axial center line of the shaft 50. The through hole 89 of the inner diameter side rotor core 80 has substantially the same diameter as that of the deepest part of the cutout holes 86 and 88.

  The rotor 12 is divided into two in the axial direction. The shaft 50 is divided into two in the axial direction, and includes two cup-shaped members 90 and 92 that are fitted to each other. The axial division position of the shaft 50 is substantially the center in the axial direction. The cup-shaped member 90 has a small-diameter cylindrical portion 74 and a part of the large-diameter cylindrical portion 72 (specifically, a half on the side connected to the small-diameter cylindrical portion 74). The cup-shaped member 92 has a small-diameter cylindrical portion 76 and a part of the large-diameter cylindrical portion 72 (specifically, a half on the side connected to the small-diameter cylindrical portion 76). The shaft 50 is formed by fitting the cup-shaped member 90 and the cup-shaped member 92 with each other. The cup-shaped member 90 supports the first outer diameter side rotor core 56, and the cup-shaped member 92 supports the second outer diameter side rotor core 58. The first outer diameter side rotor core 56 is fixed to the outer diameter surface of the cup-shaped member 90, and the second outer diameter side rotor core 58 is fixed to the outer diameter surface of the cup-shaped member 92.

  The cup-shaped members 90 and 92 are respectively formed with bolt holes 94 and 96 that are open in the axial direction on the center of the shaft. The bolt holes 94 and 96 have substantially the same diameter as the diameter of the through hole 89 of the inner diameter side rotor core 80. Bolts 98 are inserted into the bolt holes 94 and 96 of the cup-shaped members 90 and 92 and the through holes 89 of the inner diameter side rotor core 80. The cup-shaped member 90 and the cup-shaped member 92 are fastened by a bolt 98 while being fitted to each other.

  The inner diameter side rotor core 80 may be divided into two in the axial direction. In this case, the axially divided position of the inner diameter side rotor core 80 may correspond to the axially divided position of the shaft 50, or may be substantially the center in the axial direction. One of the divided inner diameter side rotor cores 80 is bonded and fixed to the inner diameter surface of the cup-shaped member 90 of the shaft 50, and the other divided one of the inner diameter side rotor core 80 is fixed to the inner diameter surface of the cup-shaped member 92. You can do that.

  FIG. 5 is a block diagram of the control device 100 for the excitation-type rotating electrical machine 10 according to the present embodiment. In the present embodiment, the excitation-type rotating electrical machine 10 is a three-phase synchronous AC motor, and has a configuration in which one end of three coils of U phase, V phase, and W phase is commonly connected to a neutral point. ing. The control device 100 is a device that controls the rotation of the rotor 12 in the excitation-type rotating electrical machine 10.

  The control device 100 is connected to an inverter 102 that converts DC power into AC power. The inverter 102 is interposed between the DC power source 104 and the stator coil 28 of each phase of the excitation type rotating electrical machine 10. The inverter 102 supplies AC power for generating torque to the excitation-type rotating electrical machine 10 using the DC power source 104. Note that a boost converter that boosts the DC voltage of the DC power supply 104 by turning on / off the pair of switching elements by using the energy storage action of the reactor may be provided between the inverter 102 and the DC power supply 104. The DC power source 104 is, for example, an in-vehicle battery such as a lithium ion battery or a hydrogen battery.

  The inverter 102 has upper and lower arms corresponding to the three-phase stator coils 28 of the excitation-type rotating electrical machine 10. The upper and lower arms of each phase include a switching element that is an upper arm element and a switching element that is a lower arm element, and are connected in series between the positive terminal and the negative terminal of the DC power supply 104. Each switching element is a power transistor such as an IGBT. The U-phase upper and lower arms, the V-phase upper and lower arms, and the W-phase upper and lower arms are connected in parallel between the positive terminal and the negative terminal of the DC power supply 104. An intermediate point between the upper arm element and the lower arm element of the upper and lower arms of each phase is connected to the other end of the stator coil 28 of the phase of the excitation type rotating electrical machine 10.

  The inverter 102 converts the DC power of the DC power source 104 into AC power and outputs it by alternately turning on / off the upper arm element and the lower arm element for each phase. On / off of each switching element which is the upper arm element and the lower arm element is controlled by a control signal from the control device 100. The control device 100 has an electronic control unit (ECU) mainly composed of a microcomputer, and is excited by software processing by executing a program stored in advance by the CPU and / or hardware processing by an electronic circuit. The operation of the rotating electrical machine 10 and the inverter 102 is controlled.

  The control device 100 is connected to the current sensor 106 and the resolver 108. The current sensor 106 outputs signals corresponding to the actual currents Iu, Iv, and Iw flowing through the stator coils 28 of the respective phases of the excitation type rotating electrical machine 10. Since the sum of instantaneous values of the three-phase actual currents Iu, Iv, and Iw is zero, the current sensor 106 outputs a signal corresponding to the two-phase actual current, and the remaining one-phase actual current May be obtained by calculation (for example, Iu = − (Iv + Iw)). The resolver 108 outputs an A-phase signal and a B-phase signal corresponding to the rotor rotation angle of the excitation type rotating electrical machine 10.

  An R / D converter 110 is connected to the resolver 108. The A-phase signal and the B-phase signal indicating the rotor rotation angle by the resolver 108 are supplied to the R / D converter 110. The R / D converter 110 converts the A phase signal and the B phase signal from the resolver 108 into digital data. A counter 112 is connected to the R / D converter 110. The digital signals of the A phase and B phase by the R / D converter 110 are supplied to the counter 112. The counter 112 counts pulses for the A-phase and B-phase digital signals from the R / D converter 110 and detects the rotor rotation angle based on the count value.

  The control device 100 is connected to the temperature sensors 107 and 109. The temperature sensor 107 detects the temperature of the exciting coil 70. The temperature sensor 107 may detect the temperature of an arbitrary place of the exciting coil 70. For example, the temperature sensor 107 may detect the temperature of the highest part of the exciting coil 70. The temperature sensor 109 detects the temperature of the stator coil 28. Similarly, the temperature sensor 109 may detect the temperature of an arbitrary place of the stator coil 28. For example, the temperature sensor 109 may detect the temperature of the highest temperature portion of the stator coil 28. The temperature sensor 109 may detect the coil temperature of any one of the three-phase coils of the stator coil 28 or may be provided for each phase. In the latter case, the highest of the phase-by-phase temperatures may be used. Hereinafter, the temperature of the excitation coil 70 detected by the temperature sensor 107 is referred to as “excitation coil temperature”, and the temperature of the stator coil 28 detected by the temperature sensor 109 is referred to as “stator coil temperature”. When doing this, it is called "coil temperature".

  The control device 100 also includes a three-phase to two-phase current converter 114 connected to the current sensor 106. Signals indicating the actual currents Iu, Iv, and Iw of each phase of the motor by the current sensor 106 are supplied to the three-phase to two-phase current converter 114. The three-phase to two-phase current converter 114 is also connected to the output of the counter 112. A signal indicating the rotor rotation angle by the counter 112 is supplied to the three-phase to two-phase current converter 114. The three-phase to two-phase current conversion unit 114 converts the three-phase actual currents Iu, Iv, and Iw of the excitation-type rotating electrical machine 10 input from the current sensor 106 into the two-phase d-axis current Id and the rotor rotation angle. By converting the coordinates to the q-axis current Iq, the d-axis current Id and the q-axis current Iq are calculated based on the three-phase actual currents Iu, Iv, and Iw.

  The control device 100 also includes a torque control unit 116. Information on the torque command value is input to the torque control unit 116 from the outside. The torque command value may be set according to a map or the like determined in advance using the vehicle speed, the accelerator operation amount, or the like, and indicates the torque to be generated by the excitation type rotating electrical machine 10. The outside may be an arbitrary ECU (for example, an ECU that controls the entire hybrid system) connected to the control device 100. The torque command value may be calculated in the control device 100 based on the vehicle speed, the accelerator operation amount, and the like. The torque control unit 116 calculates a d-axis current command value Id * and a q-axis current command value Iq * to be supplied to the d-axis and the q-axis, respectively, based on the torque command value, the modulation factor, and the like.

  The control device 100 also includes a current control unit 118. Information on the deviation between the actual value Id calculated in the three-phase to two-phase current converter 114 and the command value Id * calculated in the torque controller 116 is input to the current controller 118. At the same time, information on the deviation of the q-axis current between the actual value Iq calculated by the three-phase to two-phase current converter 114 and the command value Iq * calculated by the torque controller 116 is input. The current control unit 118 calculates the d-axis voltage command value Vd and the q-axis voltage command value Vq so that both the deviation of the input d-axis current and the deviation of the q-axis current converge to zero.

  A voltage calculation unit 120 is connected to the current control unit 118. Information on the command value Vd for the d-axis voltage and the command value Vq for the q-axis voltage calculated by the current control unit 118 is supplied to the voltage calculation unit 120. The voltage calculation unit 120 calculates the modulation factor based on the d-axis voltage command value Vd and the q-axis voltage command value Vq from the current control unit 118. A torque control unit 116 is connected to the voltage calculation unit 120. The torque control unit 116 performs field weakening control based on the modulation factor from the voltage calculation unit 120.

  The control device 100 also includes a voltage control unit 124 connected to the output of the current control unit 118 and the output of the counter 112. Information on the command value Vd of the d-axis voltage and the command value Vq of the q-axis voltage calculated by the current control unit 118 is input to the voltage control unit 124, and information on the rotor rotation angle detected by the counter 112 is input to the voltage control unit 124. Entered. The voltage control unit 124 also receives information on the voltage of the DC power supply 104. The voltage control unit 124 converts the input dq axis voltage command values Vd and Vq into three-phase voltage command values Vu, Vv, and Vw using the rotor rotation angle of the excitation-type rotating electrical machine 10, Three-phase voltage command values Vu, Vv, Vw are calculated based on the voltage command values Vd, Vq on the dq axis. The three-phase reference voltage command values Vu, Vv, and Vw are signals having equal amplitudes and phases shifted by an electrical angle of 120 °.

  The voltage control unit 124 turns on the upper and lower arms of the inverter 102 based on the result of voltage comparison between the calculated three-phase voltage command values Vu, Vv, Vw and a carrier signal (for example, a triangular wave carrier wave) having a predetermined period. A control signal for commanding off / off (specifically, a PWM signal whose pulse width is modulated) is generated. Then, the control signal is output to the inverter 102. When the control signal applied to the inverter 102 is supplied, the inverter 102 converts the DC power of the DC power supply 104 into AC power in accordance with the control signal and supplies the AC power to the stator coil 28 of each phase of the excitation type rotating electrical machine 10.

  The control device 100 is connected to a chopper circuit 130 that converts direct current power into direct current. The chopper circuit 130 is interposed between the DC power source 104 and the exciting coil 70 included in the exciting rotary electric machine 10. The chopper circuit 130 supplies DC power for generating torque to the excitation-type rotating electrical machine 10 using the DC power source 104. Specifically, for example, the DC power of the DC power supply 104 is stepped down and output by switching on / off of a switching element which is a power transistor such as an IGBT.

  The control device 100 also includes a speed calculation unit 132 connected to the output of the counter 112. A signal indicating the rotor rotation angle by the counter 112 is supplied to the speed calculation unit 132. The speed calculation unit 132 calculates the rotation speed of the excitation-type rotating electrical machine 10 based on the rotor rotation angle.

  The control device 100 is also connected to the current sensor 138 and includes a current control unit 140. The current sensor 138 outputs a signal corresponding to the actual current Idr flowing through the exciting coil 70 of the exciting rotating electrical machine 10. Information on the deviation between the actual value Idr from the current sensor 138 and the command value Idr * calculated by the torque control unit 116 of the excitation current flowing through the excitation coil 70 is input to the current control unit 140. The current control unit 140 calculates a voltage command value Vdr to be applied to the excitation coil 70 so that the deviation between the actual value Idr of the input excitation current and the command value Idr * converges to zero.

  A voltage control unit 142 is connected to the current control unit 140. Information on the voltage command value Vdr of the exciting coil 70 calculated by the current control unit 140 is supplied to the voltage control unit 142. The voltage control unit 142 controls the switching element of the chopper circuit 130 to be turned on / off so that the voltage command value Vdr from the current control unit 140 is applied to the exciting coil 70 (specifically, the pulse width is PWM signal to be modulated). Then, the control signal is output toward the chopper circuit 130. When the control signal applied to the chopper circuit 130 is supplied, the chopper circuit 130 steps down the DC power of the DC power source 104 to a desired voltage in accordance with the control signal, and the excitation type rotating electrical machine 10 is connected via the lead wire 77. The excitation coil 70 is supplied.

  In the structure of the exciting rotating electrical machine 10 described above, when a direct current is supplied to the annular exciting coil 70 using the control device 100, the magnetic flux penetrating the inner diameter side (axial center side) of the exciting coil 70 in the axial direction is changed. Occur. The magnetic flux generated by the electromagnet using the exciting coil 70 is the permanent magnet non-excited magnetic pole of the first or second outer diameter side rotor cores 56, 58 → the inner diameter side rotor core 80 → the permanent of the second or first outer diameter side rotor cores 58, 56. Magnet non-excitation magnetic pole → air gap 22 → stator core 24 → air gap 22 → first or second outer diameter side rotor cores 56 and 58 are distributed along a path consisting of permanent magnet non-excitation magnetic poles. When such a magnetic flux is generated, the permanent magnet non-excitation magnetic poles of the first and second outer diameter side rotor cores 56 and 58 are excited. The magnetic flux generated by the electromagnet weakens or strengthens the magnetic flux generated by the permanent magnets 64 and 68. The amount of magnetic flux generated by the electromagnet is adjusted according to the magnitude of the direct current flowing through the exciting coil 70.

  Therefore, according to the present embodiment, the torque for rotating the rotor 12 around the stator 14 can be adjusted by the combined magnetic flux of the magnetic flux generated by the permanent magnets 64 and 68 and the magnetic flux generated by the electromagnet using the exciting coil 70. 12 can be rotated appropriately.

  FIG. 6 shows a block configuration diagram of the torque control unit 116 of the control device 100 of the excitation-type rotating electrical machine 10 of the present embodiment.

  The torque control unit 116 has an excitation current table 136 as shown in FIG. The exciting current table 136 is used when calculating the exciting current for exciting the exciting coil 70. Information on the torque command value from the torque limiter 145 (described later) is input to the excitation current table 136, and information on the rotational speed from the speed calculator 132 and information on the DC voltage of the DC power supply 104 are input. . The excitation current table 136 stores information on command values serving as a reference of excitation current for exciting the excitation coil 70 derived from the relationship between the torque command value and the rotation speed. The information stored in the excitation current table 136 is distributed to the excitation coil 70 so that the loss (mainly copper loss) generated in the excitation coil 70 is minimized based on the relationship between the torque command value and the rotation speed. This defines the direct current excitation current. Based on the input torque command value and the rotational speed, the torque control unit 116 refers to the excitation current table 136 and calculates a reference value (that is, loss becomes minimum) of the excitation current command value Idr *. .

  As shown in FIG. 6, the torque control unit 116 includes an excitation current correction unit 144, a torque limiting unit 145, and an excitation current calculation unit 146.

  A detection value of the coil temperature (stator coil temperature, excitation coil temperature) from the temperature sensors 107 and 109 is input to the excitation current correction unit 144. Based on the coil temperature from the temperature sensors 107 and 109, the excitation current correction unit 144 generates correction command information indicating the contents to be corrected with respect to the reference excitation current command value Idr * obtained from the excitation current table 136. . An example of the operation of the excitation current correction unit 144 (generation mode of correction command information) will be described later with reference to FIG.

  The torque limiter 145 receives the detected values of the coil temperatures (stator coil temperature, excitation coil temperature) from the temperature sensors 107 and 109 and information on the torque command value from the outside. The torque limiter 145 limits the torque command value based on the coil temperature from the temperature sensors 107 and 109. For example, the torque limiter 145 performs a correction to decrease the external torque command value when either the stator coil temperature or the excitation coil temperature is higher than the temperature limit value Th2. The temperature limit value Th2 is a limit value determined from the viewpoint of preventing burning of the exciting coil 70 and the stator coil 28, and is adapted based on characteristics of the exciting coil 70 and the stator coil 28 (characteristics of the coating material, etc.). Good. For example, the temperature limit value Th2 may be a value lower than the minimum value (temperature upper limit value) of the temperature range in which the exciting coil 70 and the stator coil 28 may burn out.

  The excitation current calculation unit 146 receives the information of the reference excitation current command value Idr * calculated with reference to the excitation current table 136 as described above and the correction command information from the excitation current correction unit 144. The excitation current calculation unit 146 corrects the reference excitation current command value Idr * calculated using the excitation current table 136 according to the correction command information from the excitation current correction unit 144, and outputs the excitation current command value to be output. Idr * is generated. For example, the excitation current calculation unit 146 should output by multiplying the reference excitation current command value Idr * calculated using the excitation current table 136 by the correction coefficient related to the correction command information from the excitation current correction unit 144. An excitation current command value Idr * is generated. In this case, when the correction coefficient is larger than 1, the excitation current command value Idr * is increased, and when the correction coefficient is smaller than 1, the excitation current command value Idr * is decreased. .

  The torque control unit 116 also includes a maximum torque control unit 148 and an equal torque table 150. Information about the torque command value from the torque limiting unit 145 and information about the excitation current command value Idr * output from the excitation current calculation unit 146 are input to the maximum torque control unit 148. The maximum torque control unit 148 performs maximum torque control for deriving a current vector that minimizes the current amplitude among current vectors that cause the excitation-type rotating electricity 10 to generate the same torque corresponding to the torque command value. This maximum torque control maximizes the torque with respect to the current phase angle when the amplitude of the current vector is constant. By effectively utilizing the reluctance torque, the current can be obtained while obtaining the same output. Since the copper loss corresponding to the square of the amplitude can be minimized, high-efficiency control of the excitation-type rotating electrical machine 10 can be realized.

  A field weakening control unit 122 is connected to the maximum torque control unit 148. Information on the d-axis current command value Id * calculated by the maximum torque control unit 148 is supplied to the field weakening control unit 122. The field weakening control unit 122 performs field weakening control based on the d-axis current command value Id * from the maximum torque control unit 148 and the modulation factor from the voltage calculation unit 120, and the d-axis current command value Id after the field weakening control. The information of * is output to the current control unit 118 side.

  In addition, the torque command value information from the torque limiting unit 145 and the excitation current command value Idr * output from the excitation current calculation unit 146 are input to the equal torque table 150 and the weakening is performed. Information on the d-axis current command value Id * output from the field control unit 122 is input. In the equal torque table 150, even if the excitation current command value Idr * is changed, the q-axis current command value Iq * that equalizes the torque generated in the entire excitation rotating electric machine 10 before and after the change of the excitation current command value Idr *. Is stored. The torque control unit 116 calculates the q-axis current command value Iq * by referring to the equal torque table 150 based on the input torque command value, excitation current command value Idr *, and d-axis current command value Id *. Then, the information is output to the current control unit 118 side.

  FIG. 7 is a flowchart illustrating an example of processing executed by the torque control unit 116. The processing routine shown in FIG. 7 may be repeatedly executed at predetermined intervals during the operation of the excitation-type rotating electrical machine 10, for example.

  In step 700, either the stator coil temperature or the excitation coil temperature is higher than the temperature limit value Th2 based on the detected values (latest values) of the stator coil temperature and the excitation coil temperature input from the temperature sensors 107 and 109. It is determined whether or not. As described above, the temperature limit value Th2 is a limit value determined from the viewpoint of preventing burning of the exciting coil 70 and the stator coil 28, and is adapted based on the characteristics of the exciting coil 70 and the stator coil 28 (coating material, etc.). May be. If either the stator coil temperature or the excitation coil temperature is higher than the temperature limit value Th2, the process proceeds to step 702, and otherwise, the process proceeds to step 704. Note that the process proceeds to step 702 also when both the stator coil temperature and the exciting coil temperature are higher than the temperature limit value Th2.

  In step 702, correction is performed to reduce the external torque command value. When correction for lowering the torque command value is performed, the excitation current command value Idr * and the like are reduced, and the output torque of the excitation-type rotating electrical machine 10 is reduced (in this case, the position corresponding to the original torque command value from the outside). The output torque of the period cannot be obtained).

  In step 704, either the stator coil temperature or the excitation coil temperature is higher than the predetermined threshold Th1, based on the detected values (latest values) of the stator coil temperature and the excitation coil temperature input from the temperature sensors 107 and 109. It is determined whether or not. The predetermined threshold Th1 is a value lower than the temperature limit value Th2 used in step 700. The predetermined threshold Th1 may be set in an arbitrary manner, but may be a value within a range of 70% to 90% of the temperature limit value Th2, for example. If either the stator coil temperature or the exciting coil temperature is higher than the predetermined threshold value Th1, the process proceeds to step 706. In other cases (that is, neither the stator coil temperature nor the exciting coil temperature is higher than the predetermined threshold value Th1). In the case), the processing of the current cycle is terminated as it is. Note that if both the stator coil temperature and the exciting coil temperature are higher than the predetermined threshold Th1, the process proceeds to step 706.

  In step 706, based on the stator coil temperature input from the temperature sensors 107 and 109 and the detected value (latest value) of the exciting coil temperature, it is determined whether the exciting coil temperature is higher than the stator coil temperature. If the exciting coil temperature is higher than the stator coil temperature, the process proceeds to step 708. Otherwise (ie, the exciting coil temperature is equal to or lower than the stator coil temperature), the process proceeds to step 712.

  In step 708, correction is performed to lower (decrease) the excitation current command value Idr *.

  In step 710, correction is performed to increase (increase) the three-phase coil current command value. The three-phase coil current command value includes a d-axis current command value Id * and a q-axis current command value Iq *. “Increasing (increasing) the three-phase coil current command value” This means that the d-axis current command value Id * and the q-axis current command value Iq * are determined so that the effective value increases. Therefore, in this case, since the three-phase coil current command value is increased, unless the torque command is limited in the above step 702, the expected output torque (not reduced by torque limitation) has not been made in the excitation-type rotating electrical machine 10. Output torque).

  In step 712, correction is performed to increase (increase) the excitation current command value Idr *.

  In step 714, correction is performed to reduce (decrease) the three-phase coil current command value. Similarly, “decreasing (decreasing) the three-phase coil current command value” determines the d-axis current command value Id * and the q-axis current command value Iq * so that the effective value of the three-phase coil current is decreased. Means that. Accordingly, in this case, since the excitation current command value Idr * is increased, an expected output torque can be obtained in the excitation type rotating electrical machine 10 unless the torque command is limited in the above step 702.

  According to the process shown in FIG. 7, when either the stator coil temperature or the excitation coil temperature becomes higher than the predetermined threshold Th1, one of the excitation current command value Idr * and the three-phase coil current command value (the temperature is high). The command value for the other coil is reduced while the other is increased. Thereby, the time until the stator coil temperature and the exciting coil temperature reach the temperature limit value Th2 can be delayed, and the restriction of the torque command can be suppressed (delayed).

  In FIG. 7, the processing of step 702 and step 702 may be realized by the torque limiting unit 145 shown in FIG. Further, the processing of step 704, step 706, step 708, and step 712 may be realized in cooperation with the excitation current correction unit 144 and the excitation current calculation unit 146 shown in FIG. Further, the processing of step 710 and step 714 is realized in cooperation with the field weakening control unit 122, the excitation current correction unit 144, the excitation current calculation unit 146, the maximum torque control unit 148 and the equal torque table 150 shown in FIG. It's okay.

  8 and 9 are explanatory diagrams of the process shown in FIG. 7, and FIG. 8 shows time-series waveforms showing an example of the relationship between the limit of the torque command value and the stator coil temperature and the excitation coil temperature. FIG. 9 is a time-series waveform showing an example of the relationship between the excitation current command value Idr * and the three-phase coil current command value, the stator coil temperature, and the excitation coil temperature in relation to FIG. In FIG. 9, the three-phase coil current command value is shown as an effective value.

  Here, it is assumed that the torque command value from the outside is changed from 0 to Tq1 [Nm] at time 0 and then maintained at Tq1. In this case, as shown in FIG. 8, energization of the stator coil 28 and the excitation coil 70 is started at time 0, and the stator coil temperature and the excitation coil temperature are increased. In the example shown in FIG. 8, the exciting coil temperature increases with a steeper slope than the stator coil temperature. When the exciting coil temperature exceeds a predetermined threshold Th1 at time t1, the exciting current command value Idr * is reduced and the three-phase coil current command value is increased as shown in FIG. 9 (step of FIG. 7). 708 and step 710). Thereafter, the excitation current command value Idr * and the three-phase coil current command value are controlled so that the stator coil temperature and the excitation coil temperature become the same temperature (see step 706 to step 714 in FIG. 7). As a result, as shown in FIG. 9, an increase in the exciting coil temperature is suppressed (in the example shown, the exciting coil temperature is level, but is not limited to this), the stator coil temperature and the exciting coil The difference with temperature gradually decreases. When the stator coil temperature exceeds the predetermined threshold Th1 at time t2, the excitation current command value Idr * and the three-phase coil current command value are controlled so that the stator coil temperature and the excitation coil temperature are continuously the same. (See step 706 to step 714 in FIG. 7). As a result, as shown in FIG. 9, the stator coil temperature and the exciting coil temperature rise at substantially the same temperature. At time t3, when the stator coil temperature and the exciting coil temperature (one of which is not exactly the same) exceeds the temperature limit value Th2, a torque command limit is activated (see step 702 in FIG. 7). ), The torque command value is corrected (restricted) to a value smaller by ΔTq1 than the expected value Tq1. As a result, as shown in FIG. 9, both the excitation current command value Idr * and the three-phase coil current command value are reduced.

  FIG. 10 is a diagram illustrating a comparative example, and similarly to FIG. 8, illustrates a time-series waveform illustrating an example of a relationship between the stator coil temperature and the excitation coil temperature. In the comparative example, when either the stator coil temperature or the exciting coil temperature exceeds the temperature limit value Th2, only the torque command limit is activated, and the processing of step 706 to step 714 in FIG. 7 is not performed. is there.

  Here, similarly, it is assumed that the external torque command value is changed from 0 to Tq1 [Nm] at time 0 and then maintained at Tq1. When the exciting coil temperature exceeds the temperature limit value Th2 at time t5, the torque command limit is activated, and the torque command value becomes a value that is smaller by ΔTq2 than the expected value Tq1, as shown in FIG. It is corrected (limited). As a result, both the excitation current command value Idr * and the three-phase coil current command value are reduced. Thereafter, at time t6, the stator coil temperature exceeds the temperature limit value Th2, and the limit of the torque command value is maintained. In the example shown in FIG. 10, the excitation coil temperature is significantly lower than the temperature limit value Th2 after time t6.

  In this way, in the comparative example, as shown in FIG. 10, the torque command restriction is activated from time t5, whereas in the example shown in FIG. 8, the increase in the excitation coil temperature is suppressed from time t2. The torque command restriction is activated from time t3 (> t5). Therefore, according to the process shown in FIG. 7, it is possible to delay the time until the stator coil temperature or the excitation coil temperature reaches the temperature limit value Th <b> 2 compared with the comparative example, and suppress the activation of the torque command limit. I understand that I can do it.

  In the examples shown in FIGS. 8 and 9, the excitation current command value is set so that the stator coil temperature and the excitation coil temperature are the same even when the stator coil temperature or the excitation coil temperature exceeds the temperature limit value Th2. The Idr * and the three-phase coil current command value are controlled (see step 706 to step 714 in FIG. 7). By performing such control, the degree of limitation of the torque command value can be relaxed (ΔTq1 <ΔTq2) compared to the comparative example. This is because, for example, in the comparative example, the excitation coil temperature is significantly lower than the temperature limit value Th2 after time t6, so there is room to increase the excitation current command value Idr * and relax the degree of limitation of the torque command value. This is because the steps 706 to 714 in FIG. 7 are not executed in spite of this.

  FIG. 11 is a flowchart illustrating an example of processing of the torque limiting unit 145.

  In step 1100, based on the detected values (latest values) of the stator coil temperature and the exciting coil temperature input from the temperature sensors 107 and 109, torque limiting rates corresponding to the stator coil temperature and the exciting coil temperature are determined. The torque limit rate is, for example, 0% until the stator coil temperature exceeds the temperature limit value Th2, and increases linearly or nonlinearly toward 100% when the stator coil temperature exceeds the temperature limit value Th2. It may be determined in a manner. In this sense, the temperature limit value Th2 represents not the coil temperature (corresponding to the temperature upper limit value) when the torque command value is limited to 0, but the coil temperature when the torque command limit starts to be activated. The torque limit rate according to the coil temperature may be determined on the assumption that the processing from step 706 to step 714 in FIG. 7 is performed. By performing the processing from step 706 to step 714 in FIG. 7, it is possible to reduce the torque limiting rate with respect to the same coil temperature as compared with the configuration in which such processing is not performed. This is because, as described above, it is possible to suppress a reduction in torque generated in the entire excitation-type rotating electrical machine 10 by increasing the energization amount to the coil having the lower temperature of the excitation coil 70 and the stator coil 28. is there.

  In step 1102, each torque upper limit value after limitation is calculated by multiplying a predetermined torque upper limit value by each torque limit rate obtained in step 1100.

  In step 1104, the minimum value of each torque upper limit value after the limitation calculated in step 1102 is selected. That is, the smaller one of the torque upper limit value related to the stator coil temperature and the torque upper limit value related to the excitation coil temperature is selected.

  In step 1106, it is determined whether or not the external torque command value is less than or equal to the minimum value of the torque upper limit value selected in step 1104. If the torque command value is less than or equal to the minimum value of the torque upper limit value, the process proceeds to step 1108; otherwise, the process proceeds to step 1110.

  In step 1108, an external torque command value is output as it is. That is, the torque command limit is not activated. This output is used in the excitation current table 136, the maximum torque control unit 148, and the equal torque table 150 as described above.

  In step 1110, the minimum value of the torque upper limit value selected in step 1104 is output. In this case, the torque command restriction is activated. This output is used in the excitation current table 136, the maximum torque control unit 148, and the equal torque table 150 as described above.

  FIG. 12 is a block diagram illustrating an example of the excitation current correction unit 144.

  As shown in FIG. 12, the coil temperature (stator coil temperature and exciting coil temperature) is subtracted from a predetermined threshold Th2 (see the addition point 1441). Each difference value of the coil temperature from the predetermined threshold Th2 is corrected to 0 as the upper limit 0 in the case of positive (see saturation nonlinear element 1442). Next, each difference value passes through a feedback unit 1443 by PI (Proportional Integral) control, and thereafter, a difference df of feedback output of each difference value is taken in order to balance the stator coil temperature and the excitation coil temperature (calculation unit). 1444). In the example shown in FIG. 12, this output difference df is obtained by subtracting the feedback output of the stator coil temperature from the feedback output of the exciting coil temperature. Therefore, when the stator coil temperature is higher than the exciting coil temperature, the output difference df is positive, and when the stator coil temperature is lower than the exciting coil temperature, the output difference df is negative. This output difference df is added to a constant “1” (see addition point 1445) and output. The output c1 has a function as a correction coefficient, and becomes a value smaller than 1 when the output difference df is negative. In this case, the excitation current calculation unit 146 (see FIG. 6) multiplies the reference excitation current command value Idr * calculated using the excitation current table 136, so that the reference excitation current command value Idr * decreases in the decreasing direction. It is corrected (see step 708 in FIG. 7). On the other hand, the output c1 has a value larger than 1 when the output difference df is positive. In this case, the excitation current calculation unit 146 (see FIG. 6) multiplies the reference excitation current command value Idr * calculated using the excitation current table 136 to increase the reference excitation current command value Idr * in the increasing direction. It is corrected (see step 712 in FIG. 7). The excitation current command value Idr * corrected in this way is used in the maximum torque control unit 148 and the equal torque table 150 as shown in FIG. Therefore, when the reference excitation current command value Idr * is corrected in the decreasing direction, the three-phase coil current command value is increased in accordance with the reduction (see step 710 in FIG. 7). When the reference excitation current command value Idr * is corrected in the increasing direction, the three-phase coil current command value is reduced according to the increase (see step 714 in FIG. 7).

  Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope described in the claims. It is also possible to combine all or a plurality of the components of the above-described embodiments.

  For example, in the example illustrated in FIG. 7, the predetermined threshold Th1 is smaller than the temperature limit value Th2, but the predetermined threshold Th1 may be the same as the temperature limit value Th2. In this case, if any of the stator coil temperature and the excitation coil temperature exceeds a predetermined threshold Th1 (= temperature limit value Th2), the torque command limit is activated. At this time, the processing from step 706 to step 714 in FIG. It is good to do. Thereby, as described above, the limit degree of the torque command value can be suppressed.

  In the example shown in FIG. 7, the temperature limit value Th2 is common to the stator coil temperature and the excitation coil temperature. However, when the excitation coil 70 and the stator coil 28 have different characteristics (such as the characteristics of the coating material), different temperature limit values Th2 may be used for the stator coil temperature and the excitation coil temperature. Similarly, the predetermined threshold Th1 may be applied separately to the stator coil temperature and the excitation coil temperature. In this case, regarding the logic of Step 706 to Step 714 in FIG. 7, among the exciting current command value Idr * and the three-phase coil current command value, the increasing and decreasing directions are the stator coil temperature and the exciting coil temperature. , And may be determined based on the relationship with each temperature limit value Th2. For example, when the ratio of the stator coil temperature to the temperature limit value Th2 related to the stator coil temperature is larger than the ratio of the excitation coil temperature to the temperature limit value Th2 related to the excitation coil temperature, the three-phase coil current command value is decreased and the excitation The current command value Idr * may be increased. On the other hand, when the ratio of the stator coil temperature to the temperature limit value Th2 related to the stator coil temperature is smaller than the ratio of the excitation coil temperature to the temperature limit value Th2 related to the excitation coil temperature, the three-phase coil current command value is increased, The current command value Idr * may be decreased.

  In the example shown in FIG. 7, when either the stator coil temperature or the excitation coil temperature is higher than the temperature limit value Th2, the processing of steps 706 to 714 in FIG. 7 is executed while activating the torque command limit. Has been. However, when either the stator coil temperature or the exciting coil temperature is higher than the temperature limit value Th2, only the torque command limit is activated, and the processing from step 706 to step 714 in FIG. 7 may not be executed. .

  In the above-described embodiment, the excitation coil temperature and the stator coil temperature are detected by the temperature sensors 107 and 109, but the excitation coil temperature and the stator coil temperature may be estimated. For example, the exciting coil temperature may be estimated based on a detected value of the temperature of a part having a correlation with the exciting coil temperature. Similarly, the stator coil temperature may be estimated based on a detected value of the temperature of a portion having a correlation with the stator coil temperature. Further, the exciting coil temperature may be estimated based on an integrated value of the exciting current command value Idr * (or an integrated value of the actual value Idr) or the like. Similarly, the stator coil temperature may be estimated based on an integrated value of three-phase coil current command values (or an integrated value of actual currents Iu, Iv, and Iw).

  In the above-described embodiment, the excitation-type rotating electrical machine 10 is a three-phase motor, but the number of phases is arbitrary. Moreover, although the excitation-type rotating electrical machine 10 includes a permanent magnet excitation magnetic pole, the permanent magnet excitation magnetic pole may be omitted.

DESCRIPTION OF SYMBOLS 10 Excitation-type rotary electric machine 12 Rotor 14 Stator 22 Air gap 24 Stator core 28 Stator coil 52 Rotor core 60 Clearance 64, 68 Permanent magnet 70 Excitation coil 100 Controller 102 Inverter 104 DC power supply 106, 138 Current sensor 107, 109 Temperature sensor 108 Resolver 114 Three-phase to two-phase current conversion unit 116 Torque control unit 130 Chopper circuit 136 Excitation current table 144 Excitation current correction unit 145 Torque limit unit 146 Excitation current calculation unit 148 Maximum torque control unit 150 Equal torque table

Claims (4)

A rotor having first and second rotor cores arranged opposite to each other in the axial direction with a gap in the axial direction;
A plurality of first magnetic poles arranged at predetermined intervals in the circumferential direction on the first rotor core;
A plurality of second magnetic poles disposed at a predetermined interval in the circumferential direction in the second rotor core and disposed in a phase opposite to the first magnetic pole;
A stator that is radially opposed to the outer diameter side of the rotor via an air gap, and has a stator coil that generates a rotating magnetic field that rotates the rotor;
An exciting coil for exciting the first magnetic pole and the second magnetic pole;
An excitation device including a controller that reduces an energization amount to the one coil and increases an energization amount to the other coil when the temperature of one of the excitation coil and the stator coil is higher than a predetermined threshold value. Rotary electric machine.   When the temperature of one of the excitation coil and the stator coil is higher than a predetermined threshold, the control device reduces the amount of current supplied to the one coil without limiting the rotating electrical machine torque, and the other coil. The excitation-type rotating electrical machine according to claim 1, wherein an energization amount to the motor is increased.   The said control apparatus limits a rotary electric machine torque, when the temperature of one of the said excitation coil and the said stator coil is higher than the predetermined temperature limit value larger than the said predetermined threshold value. Excitation type rotating electrical machine.   When the temperature of one of the exciting coil and the stator coil is higher than a predetermined threshold, the control device energizes the one coil so that the temperature of the exciting coil is equal to the temperature of the stator coil. The excitation type rotating electrical machine according to any one of claims 1 to 3, wherein the amount of current supplied to the other coil is increased while the amount is reduced.

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