JP2016213948A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine that is able to improve torque density by efficiently recovering a magnetic flux change of a slip frequency as field magnetic energy and generating electromagnetic torque by means of the recovered field magnetic energy.SOLUTION: In the rotary electric machine 100, an outer rotor 20 has a frequency difference induction coil Iim in which a magnetic flux of a frequency difference between the first frequency of the outer rotor and the second frequency of an inner rotor crosses an inside salient pole 22 provided on a side opposite the inner rotor 30. On the radial outer peripheral side of an outside salient 23 provided on a side opposite a stator 10, the outer rotor has a harmonic wave induction coil Is crossed by a harmonic wave included in a magnetic flux generated in the stator 10. On the radial inner peripheral side of an outside salient pole 23, the outer rotor has a field magnetic coil WF supplied with an electric current generated in the harmonic wave induction coil Is and the frequency difference induction coil Iim.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a double rotor type rotating electrical machine having an outer rotor and an inner rotor.

  As a rotating electrical machine mounted on a hybrid vehicle or the like, a double rotor type rotating electrical machine in which an outer rotor and an inner rotor are coaxially arranged has been proposed.

  Conventionally, as this type of double-rotor type rotating electrical machine, one described in Patent Document 1 is known. The rotating electrical machine described in Patent Document 1 includes a stator in which coils are distributedly wound, an outer rotor configured as an embedded magnet type rotor, and an inner rotor configured as a winding type induction rotor.

  In this rotating electrical machine, the outer rotor and the inner rotor are coupled by magnetic coupling, so that kinetic energy such as engine power input to the inner rotor can be transmitted as magnetic energy to the outer rotor by a magnetic coupling effect. The outer rotor can transmit magnetic energy as kinetic energy to the output shaft.

JP 2015-16740 A

  Here, in the conventional rotating electrical machine, when the outer rotor rotates in synchronization with the rotating magnetic field generated in the stator, the magnet disposed on the inner rotor side of the outer rotor generates a rotating magnetic field when observed from the stationary coordinate system. .

  When the inner rotor rotates with slip with respect to the outer rotor, “flux fluctuation of slip frequency” generated by the frequency difference between the outer rotor and the inner rotor is linked to the outer rotor.

  However, since the magnetic flux fluctuation at the slip frequency is an asynchronous component with respect to the inner rotor, the magnetic flux fluctuation at the slip frequency increases the iron loss and magnet eddy current loss of the outer rotor.

  Moreover, since the magnetic flux fluctuation | variation of a slip frequency becomes reactive energy, it will reduce a power factor. When the power factor is lowered, the torque / voltage ratio is deteriorated. Therefore, under the limited DC voltage limit, the variable speed torque characteristic may be lowered due to the limitation of the voltage.

  Therefore, the present invention can efficiently recover the magnetic flux fluctuation of the slip frequency generated between the outer rotor and the inner rotor as field energy, and generate the electromagnet torque by the recovered field energy to improve the torque density. The object is to provide a rotating electrical machine that can be used.

  According to one aspect of the invention of a rotating electrical machine that solves the above-described problem, a stator having an armature coil that generates a magnetic flux by supplying an alternating current and a rotating shaft side of the stator are provided, and the first is achieved by interlinking of the magnetic flux. A rotating electrical machine having a first rotor that rotates at a frequency different from the first rotor and a second rotor that is provided closer to the rotating shaft than the first rotor and rotates at a second frequency different from the first frequency. In the first rotor, a magnetic flux having a frequency difference between the first frequency and the second frequency is linked to an inner salient pole provided on the side facing the second rotor. A harmonic induction coil having a frequency difference induction coil and having harmonics included in the magnetic flux generated in the stator interlink on the radially outer peripheral side of the outer salient pole provided on the side facing the stator. A diameter of the outer salient pole The Mukonai circumferential side, and a material having a magnetic coil field current generated by the harmonic induction coil and the induction coil the frequency difference is supplied.

  As described above, according to the present invention, the magnetic flux fluctuation of the slip frequency generated between the outer rotor and the inner rotor is efficiently recovered as field energy, and electromagnetic torque is generated by the recovered field energy to improve the torque density. Can be made.

FIG. 1 is a diagram illustrating a configuration of a rotating electrical machine according to an embodiment of the present invention, and is a cross-sectional view of the rotating electrical machine cut along a plane orthogonal to a rotating shaft. FIG. 2 is a diagram illustrating a configuration of the rotating electrical machine according to the embodiment of the present invention, and is a cross-sectional view illustrating details of the rotating electrical machine. FIG. 3 is a diagram illustrating a rotating electrical machine according to an embodiment of the present invention, and is a diagram illustrating a full-wave rectifier circuit provided in an outer rotor. FIG. 4 is a diagram illustrating a rotating electrical machine according to an embodiment of the present invention, and is a diagram illustrating a configuration of a hybrid drive system including the rotating electrical machine. FIG. 5 is a collinear diagram of a rotating electrical machine having a configuration of a magnetic modulation type magnet-free magnetic gear motor as a comparative example. FIG. 6 is a cross-sectional view showing a configuration of a rotating electrical machine having a configuration of a magnetic modulation type magnet-free magnetic gear motor as a comparative example. FIG. 7 is a view showing a rotating electrical machine according to an embodiment of the present invention, and is a collinear diagram of the rotating electrical machine. FIG. 8 is a view showing a rotating electrical machine according to an embodiment of the present invention, and is a cross-sectional view showing a state where a magnetic coupling effect is generated in the rotating electrical machine. FIG. 9 is a diagram illustrating the rotating electrical machine according to the embodiment of the present invention, and is a collinear diagram of the rotating electrical machine when the slip of the inner rotor is positive. FIG. 10 is a view showing the rotating electrical machine according to the embodiment of the present invention, and is a cross-sectional view showing the magnetic flux density of the rotating electrical machine when the slip of the inner rotor is positive. FIG. 11 is a diagram illustrating the rotating electrical machine according to the embodiment of the present invention, and is a collinear diagram of the rotating electrical machine when the slip of the inner rotor is negative. FIG. 12 is a view showing the rotating electrical machine according to the embodiment of the present invention, and is a cross-sectional view showing the magnetic flux density of the rotating electrical machine when the slip of the inner rotor is negative. FIG. 13 is a diagram illustrating a rotating electrical machine according to an embodiment of the present invention, and is a diagram illustrating a variable speed torque characteristic of the outer rotor with respect to the speed of the inner rotor. FIG. 14 is a diagram illustrating the rotating electrical machine according to the embodiment of the present invention, and is a cross-sectional view illustrating the magnetic flux density of the rotating electrical machine when the slip between the inner rotor and the outer rotor is small. FIG. 15 is a diagram showing a change in rotor current when the slip of the inner rotor is in the state shown in FIG. FIG. 16 is a diagram illustrating the rotating electrical machine according to the embodiment of the present invention, and is a cross-sectional view illustrating the magnetic flux density of the rotating electrical machine when the slip between the inner rotor and the outer rotor is large. FIG. 17 is a diagram showing a change in rotor current when the slip of the inner rotor is in the state shown in FIG. FIG. 18 is a diagram illustrating a rotating electrical machine according to an embodiment of the present invention, and is a cross-sectional view illustrating the magnetic flux density of the rotating electrical machine when secondary excitation is performed when the slip of the inner rotor is zero. FIG. 19 is a diagram showing the rotor current in the rotating electrical machine in the state of FIG. FIG. 20 is a diagram illustrating a rotating electrical machine according to an embodiment of the present invention, and is a cross-sectional view illustrating the magnetic flux density of the rotating electrical machine when secondary excitation is not performed when the slip of the inner rotor is zero. FIG. 21 is a diagram showing a rotor current in the rotating electrical machine in the state of FIG. FIG. 22 is a diagram comparing the torque in the rotating electrical machine in the state with secondary excitation in FIG. 18 and the state without secondary excitation in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIGS. 1-22 is a figure explaining the rotary electric machine which concerns on one Embodiment of this invention.
<Schematic configuration of rotating electrical machine>

In FIG. 1, a rotating electrical machine 100 is configured as a double rotor type rotating electrical machine, and has a stator 10 formed in a cylindrical shape and a first rotor provided on the rotating shaft 100 c side from the stator 10. The outer rotor 20 and an inner rotor 30 as a second rotor provided on the rotating shaft 100c side with respect to the outer rotor 20 are provided. The outer rotor 20 and the inner rotor 30 are supported so as to be relatively rotatable about the rotation shaft 100c as a rotation center.
<Detailed configuration of rotating electrical machine>

  In FIG. 2, the stator 10 includes a stator core 11 and an armature coil 14. Here, FIG. 2 shows a radial sectional view of 60 degrees (1/6) of the mechanical angle of 360 degrees.

  A plurality of stator teeth 12 are formed on the inner peripheral side of the stator core 11, that is, the side facing the outer rotor 20, and the stator teeth 12 are extended in the radial direction toward the rotary shaft 100c and are extended in the circumferential direction. They are arranged side by side at equal intervals.

  The recesses sandwiched between the side surfaces of the stator teeth 12 adjacent to each other constitute a slot 13. The slot 13 houses armature coils 14 corresponding to the three-phase AC W-phase, V-phase, and U-phase.

  The armature coil 14 is wound around the stator tooth 12 by concentrated winding. The armature coil 14 generates a rotating magnetic field that rotates in the circumferential direction when supplied with a three-phase alternating current.

  The outer rotor 20 is configured as a self-excited wire wound field rotor, and includes a rotor yoke 21, a field coil WF, a frequency difference induction coil Iim, and a harmonic induction coil Is.

  The rotor yoke 21 is made of a magnetic material such as steel having a high magnetic permeability, and forms a magnetic path therein. A plurality of inner salient poles 22 are provided on the inner circumferential side of the rotor yoke 21, that is, the side facing the inner rotor 30, and the inner salient poles 22 are arranged at equal intervals in the circumferential direction. The inner peripheral surface of the inner salient pole 22 is opposed to the outer peripheral surface of a rotor tooth 32 (described later) of the inner rotor 30 via the air gap G2.

  The recesses sandwiched between the side surfaces of the inner salient poles 22 adjacent to each other constitute an inner slot 25. The inner slot 25 stores a frequency difference induction coil Iim. The frequency difference induction coil Iim is wound around the inner salient pole 22 by concentrated winding. A magnetic flux having a frequency difference between a first frequency F1 [Hz] and a second frequency F2 [Hz], which will be described later, is linked to the frequency difference induction coil Iim.

  A plurality of outer salient poles 23 are provided on the outer circumferential side of the rotor yoke 21, that is, the side facing the stator 10, and the outer salient poles 23 are arranged at equal intervals in the circumferential direction. The outer peripheral surface of the outer salient pole 23 faces the inner peripheral surface of the stator teeth 12 of the stator 10 via the air gap G1. The recesses sandwiched between the side surfaces of the outer salient poles 23 adjacent to each other constitute an outer slot 24.

  Thus, the rotor yoke 21 of the outer rotor 20 has a salient pole structure on both the air gap G1 side surface facing the stator 10 and the air gap G2 side surface facing the inner rotor 30. The inner salient pole 22 and the outer salient pole 23 have a magnetic path formed by the rotor yoke 21.

  The outer slot 24 accommodates a harmonic induction coil Is and a field coil WF. The harmonic induction coil Is is wound around the outer periphery of the outer salient pole 23 by concentrated winding. The harmonics included in the magnetic flux generated in the stator 10 are linked to the harmonic induction coil Is.

  The field coil WF is wound around the inner periphery of the outer salient pole 23 by concentrated winding. The AC current generated in the harmonic induction coil Is and the frequency difference induction coil Iim is rectified and supplied to the field coil WF by a full-wave rectifier circuit C (see FIG. 3) described later.

  The outer rotor 20 rotates at a first frequency F <b> 1 that is synchronized with the frequency of the alternating current supplied to the stator 10.

  In FIG. 2, two frequency difference induction coils Iim wound around adjacent inner salient poles 22 are denoted as Iim1 and Iim2. Further, two harmonic induction coils Is wound around the radially outer peripheral side of the adjacent outer salient poles 23 are denoted by Is1 and Is2. Further, two field coils WF wound around the radially inner peripheral side of the adjacent outer salient poles 23 are denoted as WF1 and WF2.

  The outer rotor 20 includes a full-wave rectifier circuit C shown in FIG. In FIG. 3, the full-wave rectifier circuit C is composed of a full-wave rectifier circuit C1 for harmonics, a full-wave rectifier circuit C2 for frequency difference, and field coils WF1 and WF2.

  The harmonic full-wave rectifier circuit C1 is formed by connecting harmonic induction coils Is1 and Is2 and diodes D1 and D2 in series.

  The frequency difference full-wave rectifier circuit C2 is formed by connecting frequency difference induction coils Iim1 and Iim2 and diodes D1 and D2 in series.

  The field coil WF1 and the field coil WF2 are connected in series. The harmonic full-wave rectifier circuit C1 and the frequency difference full-wave rectifier circuit C2 are connected in parallel to the field coil WF1 and the field coil WF2.

  The full-wave rectifier circuit C rectifies the alternating current generated in the harmonic induction coil Is (Is1, Is2) and the frequency difference induction coil Iim (Iim1, Iim2) into a direct current, and field coils WF (WF1, WF2). ).

  The inner rotor 30 is configured as a winding induction rotor and includes a rotor core 31 and an excitation coil 34.

  A plurality of rotor teeth 32 are formed on the outer peripheral side of the rotor core 31, that is, the side facing the outer rotor 20. The rotor teeth 32 are extended in a direction away from the rotation shaft 100 c and are equally spaced in the circumferential direction. Is arranged in.

  The recesses sandwiched between the side surfaces of the adjacent rotor teeth 32 constitute a slot 33. In the slot 33, excitation coils 34 corresponding to the respective phases of the three-phase alternating current are accommodated.

  The exciting coil 34 is wound around the rotor tooth 32 by distributed winding. The exciting coil 34 is secondarily excited by supplying an alternating current to generate a magnetic flux. The exciting coil 34 generates (induces) an induced current when the interlinkage magnetic flux density changes. The outer peripheral surface of the rotor teeth 32 faces the inner peripheral surface of the rotor yoke 21 of the outer rotor 20 through the air gap G2. Since the inner rotor 30 is supported so as to be rotatable relative to the outer rotor 20, the inner rotor 30 rotates at a second frequency F2 different from the first frequency F1 of the outer rotor 20. The second frequency F2 is a frequency asynchronous with the frequency (F1) of the alternating current supplied to the stator 10.

  Here, in the rotating electrical machine 100, the pole combination of the stator 10 and the salient pole of the outer rotor 20 has a pole: slot of 2: 3. That is, the rotating electrical machine 100 is configured such that the number P of the outer salient poles 23 on the outer rotor 20 side and the number S of the slots 13 on the stator 10 side are 2: 3.

  Thereby, magnetic fluxes having a uniform density distribution can be linked over the entire circumference of the mechanical angle of 360 degrees, and the outer rotor 20 can be rotated in the stator 10 with high quality. Since the rotating operation can be performed using the spatial harmonic magnetic flux, the loss energy can be efficiently recovered, the electromagnetic vibration can be greatly reduced, and the rotating can be performed with high silence.

  The number of rotor teeth of the inner rotor 30 (number of rotor teeth 32) is preferably 6 × P, where P is the number of poles. In the rotating electrical machine 100 of the present embodiment, the number of poles P is 12, and the number of rotor teeth is 6 × 12 = 72.

  That is, in the inner rotor 30, the exciting coil 34 is wound in distributed winding around a rotor tooth 32 that forms a slot number that is six times the number of poles. The coil pitch is secured by such distributed winding, the amount of magnetic flux interlinking with the exciting coil 34 can be increased, and the torque density can be improved.

With the above structure, the engine output can be transmitted from the inner rotor 30 to the outer rotor 20 by magnetic coupling between the motors.
<Hybrid drive system using the rotating electrical machine of this embodiment>

  In FIG. 4, the rotating electrical machine 100 constitutes a hybrid drive system 200 together with an engine 201, a drive shaft 202, and a drive circuit 250.

  The output shaft 30A of the inner rotor 30 is connected to the engine 201, and the inner rotor 30 rotates integrally with the engine 201. The output shaft 20 </ b> A of the outer rotor 20 is connected to the drive shaft 202, and the outer rotor 20 rotates integrally with the drive shaft 202. A slip ring 39 corresponding to each phase of the three-phase alternating current is provided on the output shaft 30A of the inner rotor 30 so as to be integrally rotatable.

  The drive circuit 250 includes a battery 251, an inverter 252, and an inverter 253. The battery 251 includes a secondary battery, and is connected to the inverter 252 and the inverter 253, respectively.

  The inverter 252 is connected to the armature coil 14 of the stator 10. The inverter 252 converts the direct current electricity extracted from the battery 251 into a three-phase alternating current, and supplies the three-phase alternating current to the armature coil 14.

  The inverter 253 is connected to the exciting coil 34 of the inner rotor 30 via the slip ring 39. The inverter 253 converts the direct current electricity extracted from the battery 251 into a three-phase alternating current and supplies the three-phase alternating current to the exciting coil 34.

The inner rotor 30 is secondarily excited by the alternating current supplied from the inverter 253. Note that the structure for secondary excitation of the inner rotor 30 may be a brushless secondary excitation structure. In the brushless secondary excitation structure, although not shown, the FSM (not shown) is excited by a direct current from the battery 251 to generate a sinusoidal magnetic flux that fluctuates at its rotational frequency on the inner rotor 30.
<Comparison in collinear diagram of rotating electrical machine of this embodiment and magnetic modulation type magnet free magnetic gear motor as comparative example>

  5 and 6 show a collinear diagram and a configuration diagram of a magnetic modulation type magnetic gear motor as a comparative example, respectively. 7 and 8 show an alignment chart and a configuration diagram of the rotating electrical machine 100 of the present embodiment, respectively.

  As shown in FIG. 8, in the rotating electrical machine 100, the three-phase alternating current having the second frequency F <b> 2 is supplied to the exciting coil 34 of the inner rotor 30. The exciting coil 34 is secondarily excited by a three-phase alternating current having the second frequency F2.

  As shown in FIG. 6, the magnetic modulation type magnetic gear motor 300 is configured as a magnet-free type motor including a stator 310, a modulator 320, and a wound type field rotor 330. In the stator 310, a plurality of stator teeth 311 extending in the radial direction toward the axial center are arranged in parallel in the circumferential direction. An armature coil 313 is wound around the stator 310 by distributed winding with the slots 312 between the side surfaces of the stator teeth 311. The modulator 320 has a prismatic magnetic path member 321 made of a soft magnetic material such as a steel material having a high magnetic permeability and is extended in the axial direction and arranged in parallel in the circumferential direction, and is formed in the form of a rotor of a so-called cage motor. Has been. That is, the modulator 320 is formed by alternately arranging magnetic path members 321 that allow magnetic flux to pass through and gaps 322 that do not pass magnetic flux in the circumferential direction. As a result, when the modulator 320 rotates relative to the stator 310, the magnetic path member 321 through which the magnetic flux passes and the gap 322 that restricts the passage of the magnetic flux are repeatedly switched to form a magnetic circuit. The coiled field rotor 330 is provided with an induction coil 334 on the radially outer side and an excitation coil 335 on the radially inner side. In such a magnetic modulation type magnetic gear motor 300, as shown in FIG. 5, the stator 310, the wound field rotor 330, and the modulator 320 all rotate asynchronously.

On the other hand, in the rotating electrical machine 100 of the present embodiment, as shown in FIG. 7, the rotating magnetic field generated by the stator 10 and the outer rotor 20 are rotated synchronously. In the rotating electrical machine 100, the inner rotor 30 rotates asynchronously with respect to the outer rotor 20 or the stator 10.
<Example of drive mode of rotating electrical machine>

  The rotating electrical machine 100 has a structure in which the output shafts of the outer rotor 20 and the inner rotor 30 are independent.

  For this reason, as shown in FIGS. 9 and 10, the rotating electrical machine 100 can drive the inner rotor 30 so that the inner rotor 30 rotates with a delay with respect to the rotating magnetic field, that is, the slip is positive. 9 and 10, the stator 10 and the outer rotor 20 are rotated synchronously. Further, the inner rotor 30 rotates asynchronously with the rotating magnetic field of the stator 10 and the outer rotor 20 at a low speed.

Moreover, as shown in FIGS. 11 and 12, the rotating electrical machine 100 can drive the inner rotor 30 such that the inner rotor 30 is rotated forward with respect to the rotating magnetic field, that is, the slip is in a negative state. 11 and 12, the stator 10 and the outer rotor 20 are rotated in synchronization. Further, the inner rotor 30 is asynchronously rotated at a high speed with respect to the rotating magnetic field of the stator 10 and the outer rotor 20. 10 and 12, the outer rotor 20 and the inner rotor 30 are rotated counterclockwise.
<Variable speed torque characteristics of the outer rotor relative to the inner rotor>

  As shown in FIG. 13, the rotating electrical machine 100 makes the rotational speed of the inner rotor 30 faster than the outer rotor 20 (the slip s is in a negative state), so that the kinetic energy of the inner rotor 30 is transferred to the outer rotor 20 by a magnetic coupling effect. Can communicate. In other words, torque due to the magnetic coupling effect, that is, magnetic coupling torque can be transmitted from the inner rotor 30 to the outer rotor 20.

  Here, in a conventional rotating electrical machine using a permanent magnet for the outer rotor, the magnetic flux fluctuation at the slip frequency is a loss. On the other hand, in the rotating electrical machine 100 of this embodiment, the frequency difference induction coil Iim wound around the outer rotor 20 efficiently recovers the magnetic flux fluctuation of the slip frequency as field energy, and the recovered field energy is an electromagnet. Torque can be generated to improve torque density.

  Specifically, in the rotating electrical machine 100 of the present embodiment, an alternating induction current is generated in the harmonic induction coil Is by harmonics included in the magnetic flux generated in the stator 10, and induction is caused by magnetic flux fluctuations of the slip frequency. An alternating induction current is generated in the frequency difference induction coil Iim by the voltage. Then, the AC induced current is rectified into a DC current via the full-wave rectifier circuit C, thereby generating a DC magnetic flux in the field coil WF of the outer rotor 20 and obtaining a strong magnetic field effect.

  That is, in the rotating electrical machine 100, spatial harmonics are generated due to the concentrated winding of the armature coil 14 of the stator 10. The spatial harmonics are collected by the harmonic induction coil Is, and the outer rotor 20 is recovered. It can be used as a field energy source for the field coil WF.

  Further, in the rotating electrical machine 100, a slip frequency is generated between the inner rotor 30 and the outer rotor 20 due to the asynchronous double rotor structure having the outer rotor 20 and the inner rotor 30, and this slip frequency is a frequency. It can be recovered by the difference induction coil Iim and used as field energy to the field coil WF of the outer rotor 20.

  Further, in the rotating electrical machine 100, since the outer salient pole 23 is formed on the rotor yoke 21 of the outer rotor 20, the magnetic flux generated in the stator 10 mainly uses the outer salient pole 23 with low magnetic resistance (high permeability). It is formed as a magnetic flux that passes between the outer slot 24 and the inner slot 25 and returns from the adjacent outer salient pole 23 to the stator 10. At this time, it tries to reduce the length of the magnetic flux to the shortest distance. The force that the magnetic flux tries to contract acts as a reluctance torque so that the outer rotor 20 rotates synchronously with the rotating magnetic field of the stator 10. That is, the rotating electric machine 100 can use the reluctance torque by forming the outer salient pole 23 on the rotor yoke 21 of the outer rotor 20.

As described above, the rotating electrical machine 100 according to the present embodiment includes the electromagnet generated when the induction current induced by the harmonic induction coil Is and the frequency difference induction coil Iim of the outer rotor 20 is supplied to the field coil WF. The torque, the reluctance torque generated by the magnetic flux passing through the outer salient pole 23 formed on the rotor yoke 21 of the outer rotor 20, and the rotational speed of the inner rotor 30 are made faster than the outer rotor 20 (the slip s is made negative). The torque density of the outer rotor 20 can be improved by utilizing the magnetic coupling torque that acts as a reaction due to this.
<Induced current flowing in frequency difference induction coil and harmonic induction coil>

  FIG. 14 shows a state of the rotating electrical machine 100 when the inner rotor 30 and the outer rotor 20 are rotated at 3500 rpm and 2000 rpm, respectively. In FIG. 14, the stator 10 generates a rotating magnetic field in the counterclockwise direction, and the outer rotor 20 rotates at 2000 rpm in synchronization with this rotating magnetic field. Further, the inner rotor 30 rotates counterclockwise at a speed 1500 rpm faster than the outer rotor 20 with the slip s being negative.

  FIG. 15 shows induced currents flowing through the frequency difference induction coil Iim and the harmonic induction coil Is when the inner rotor 30 and the outer rotor 20 are rotated at 3500 rpm and 2000 rpm, respectively.

  FIG. 16 shows a state of the rotating electrical machine 100 when the inner rotor 30 and the outer rotor 20 are rotated at 5000 rpm and 2000 rpm, respectively. In FIG. 16, the stator 10 generates a rotating magnetic field in the counterclockwise direction, and the outer rotor 20 rotates at 2000 rpm in synchronization with the rotating magnetic field. Further, the inner rotor 30 rotates counterclockwise at a speed 3000 rpm faster than the outer rotor 20 with the slip s being negative.

  FIG. 17 shows induction currents flowing through the frequency difference induction coil Iim and the harmonic induction coil Is when the inner rotor 30 and the outer rotor 20 are rotated at 5000 rpm and 2000 rpm, respectively.

  15 and 17, the line indicated as “stator side” indicates the induced current flowing through the harmonic induction coil Is, and the line indicated as “inner rotor side” indicates the induced current flowing through the frequency difference induction coil Iim. ing. Further, “(positive)” indicates that the direction of the induced current before commutation is a direction in which the outer rotor 20 is rotated counterclockwise, and “(reverse)” indicates that the direction of the induced current before commutation is the outer rotor 20. This indicates that the rotation direction is clockwise.

  As can be seen from FIGS. 15 and 17, the harmonic induction coil Is generates an induction current of a third harmonic per electrical angle period, and the armature coil 14 of the stator 10 is concentrated winding. It can be confirmed that the third time harmonic generated due to the above can be utilized as a field energy source of the field coil WF of the outer rotor 20. Here, the third-order time harmonic is a second-order spatial harmonic in the stationary coordinate system.

  In addition, an induction current due to the slip frequency is generated in the frequency difference induction coil Iim, and magnetic flux fluctuation due to the slip frequency can be utilized as a field energy source to the field coil WF of the outer rotor 20. I can confirm.

Further, comparing FIG. 15 with FIG. 17, in the frequency difference induction coil Iim indicated as “inner rotor side”, FIG. 17 having a higher slip frequency generates more induced current than FIG. 15. I understand. For this reason, the field energy to the field coil WF can be obtained more in FIG. 17 where the magnetic flux fluctuation due to the slip frequency is larger than in FIG.
<Comparison of induced current flowing in frequency difference induction coil and harmonic induction coil with and without secondary excitation when slip = 0>

  FIG. 18 shows the state of the rotating electrical machine 100 when the inner rotor 30 and the outer rotor 20 are rotating in synchronization with the rotating magnetic field and the secondary excitation of the inner rotor 30 is present, in which the slip s = 0. In FIG. 18, the stator 10 generates a rotating magnetic field in the counterclockwise direction, and the outer rotor 20 and the inner rotor 30 are rotated at 1000 rpm in synchronization with the rotating magnetic field.

  FIG. 19 shows the induced current flowing through the frequency difference induction coil Iim and the harmonic induction coil Is when the rotating electrical machine 100 is in the state shown in FIG.

  FIG. 20 shows a state of the rotating electrical machine 100 when the inner rotor 30 and the outer rotor 20 are rotating synchronously with the rotating magnetic field and the secondary excitation of the inner rotor 30 is not performed, in which the slip s = 0. In FIG. 20, the stator 10 generates a rotating magnetic field in the counterclockwise direction, and the outer rotor 20 and the inner rotor 30 are rotated at 1000 rpm in synchronization with the rotating magnetic field.

  FIG. 21 shows the induced current flowing through the frequency difference induction coil Iim and the harmonic induction coil Is when the rotating electrical machine 100 is in the state shown in FIG.

  19 and 21, a line indicated as “stator side” indicates an induction current flowing through the harmonic induction coil Is, and a line indicated as “inner rotor side” indicates an induction current flowing through the frequency difference induction coil Iim. ing. Further, “(positive)” indicates that the direction of the induced current before commutation is a direction in which the outer rotor 20 is rotated counterclockwise, and “(reverse)” indicates that the direction of the induced current before commutation is the outer rotor 20. This indicates that the rotation direction is clockwise. In FIG. 21, the inner rotor side (positive) is 0 and constant.

  When the inner rotor 30 is subjected to secondary excitation as shown in FIG. 18, unlike the case where the inner rotor 30 is not subjected to secondary excitation as shown in FIG. 20, the magnetic flux due to the secondary excitation of the inner rotor 30 acts on the outer rotor 20. Excitation interference acts on the third time harmonic on 20 and the magnetic flux fluctuation of the slip frequency.

  For this reason, when the inner rotor 30 is subjected to secondary excitation as shown in FIG. 19, the current on the inner rotor side (forward) and the inner rotor side (reverse) is larger than that in FIG. 21, and the current on the stator side (forward) and stator side (reverse) is increased. Is less than in FIG. Thereby, when the inner rotor 30 is subjected to secondary excitation, the amount of spatial harmonic energy (current on the stator side (forward) and stator side (reverse)) that can be recovered by the harmonic induction coil Is of the outer rotor 20 is reduced from FIG. However, the slip frequency energy (current on the inner rotor side (forward) and inner rotor side (reverse)) due to the slip frequency increases from FIG.

  For this reason, as shown in FIG. 22, the torque of the inner rotor (without secondary excitation) is constant at 0, and the inner rotor (with secondary excitation) only generates a torque that fluctuates positively or negatively. With the next excitation, it is possible to obtain more torque that varies on the positive side than the outer rotor (without the second excitation). Therefore, when comparing the torque with and without secondary excitation, the torque of the outer rotor 20 is improved in the case of secondary excitation than in the case of no secondary excitation.

  That is, even in the synchronous mode of the slip s = 0, when the inner rotor 30 is subjected to secondary excitation, a rotating magnetic field is generated in the inner rotor 30, and a magnetic coupling is formed between the inner rotor 30 and the outer rotor 20 by the rotating magnetic field. As a result of the torque generated in the inner rotor 30 being transmitted to the outer rotor 20 by this magnetic coupling, the torque of the outer rotor 20 can be improved.

  The effect of the rotary electric machine of this embodiment demonstrated as mentioned above is demonstrated.

  The rotating electrical machine 100 according to the present embodiment is provided with a stator 10 having an armature coil 14 that generates magnetic flux by supplying an alternating current, and a linkage of magnetic flux generated in the stator 10 that is provided closer to the rotating shaft 100c than the stator 10. Thus, the outer rotor 20 that rotates at the first frequency F1 and the inner rotor 30 that is provided closer to the rotating shaft 100c than the outer rotor 20 and rotates at the second frequency F2 different from the first frequency F1 are provided.

  In addition, the outer rotor 20 has a frequency difference induction coil Iim in which a magnetic flux having a frequency difference between the first frequency F1 and the second frequency F2 is linked to an inner salient pole 22 provided on the side facing the inner rotor 30. The outer salient pole 23 provided on the side facing the stator 10 has a harmonic induction coil Is interlinked with harmonics included in the magnetic flux generated in the stator 10 on the outer peripheral side in the radial direction. A field coil WF to which current generated in the harmonic induction coil Is and the frequency difference induction coil Iim is supplied is provided on the radially inner side of the salient pole 23.

  According to the rotating electrical machine 100, the outer rotor 20 and the inner rotor 30 rotate at the first frequency F1 and the second frequency F2, respectively, so that a magnetic flux fluctuation with a slip frequency is generated between the outer rotor 20 and the inner rotor 30.

  In addition, a magnetic flux having a frequency difference between the first frequency F1 and the second frequency F2 is linked to the frequency difference induction coil Iim, so that an induction current is generated in the frequency difference induction coil Iim.

  Moreover, the harmonic contained in the magnetic flux generated in the stator 10 is linked to the harmonic induction coil Is, so that an induction current is generated in the harmonic induction coil Is.

  The current generated in the harmonic induction coil Is and the frequency difference induction coil Iim is supplied to the field coil WF, thereby generating an electromagnet torque.

  As a result, magnetic flux fluctuations at the slip frequency can be efficiently recovered as field energy, and electromagnet torque can be generated by the recovered field energy to improve the torque density.

  Furthermore, according to this rotating electrical machine 100, in addition to the reluctance torque, the electromagnet torque can be generated by the field coil WF, so that it is possible to avoid an increase in cost due to the use of a permanent magnet.

  In the rotating electrical machine 100 of the present embodiment, the outer rotor 20 is a full-wave rectifier circuit that rectifies an alternating current generated in the harmonic induction coil Is and the frequency difference induction coil Iim into a direct current and supplies the direct current to the field coil. C.

  According to the rotating electric machine 100, the field of the outer rotor 20 is rectified by rectifying the alternating induction current generated in the frequency difference induction coil Iim and the harmonic induction coil Is into a direct current through the full-wave rectification circuit C. A direct magnetic flux can be generated in the magnetic coil WF to obtain a strong magnetic field effect.

  In the rotating electrical machine 100 of the present embodiment, the outer rotor 20 rotates at the first frequency F1 that is synchronized with the frequency of the alternating current supplied to the stator 10, and the inner rotor 30 is the first that is asynchronous with the first frequency. Rotate at a frequency of F2.

  According to this rotating electrical machine 100, by rotating the outer rotor 20 at the first frequency F1 that is synchronized with the frequency of the alternating current supplied to the stator 10, the magnetic flux fluctuation of the slip frequency between the outer rotor 20 and the inner rotor 30 causes A magnetic coupling is formed between the inner rotor 30 and the outer rotor 20, and torque generated in the inner rotor 30 can be transmitted to the outer rotor 20 by this magnetic coupling.

  Further, in the rotating electrical machine 100 of the present embodiment, the inner rotor 30 has an exciting coil 34 that generates magnetic flux by secondary excitation, and the exciting coil 34 includes a plurality of salient poles including slots 33 that are six times the number of poles. As a result, the rotor teeth 32 are distributedly wound.

  Thus, since the exciting coil 34 is distributedly wound around the plurality of rotor teeth 32 composed of the slots 33 having six times the number of poles, the coil pitch is secured by this distributed winding, and the amount of magnetic flux interlinked with the exciting coil 34. And the torque density can be improved.

  According to this rotating electrical machine 100, secondary excitation of the excitation coil 34 of the inner rotor 30 causes excitation interference due to third-order harmonics on the outer rotor 20 and magnetic flux fluctuations of the slip frequency, resulting in the slip frequency. The sliding frequency energy can be increased.

  As a result, even in the synchronous mode of the slip s = 0, the inner rotor 30 is subjected to secondary excitation to form a magnetic coupling between the inner rotor 30 and the outer rotor 20 by the rotating magnetic field generated by the inner rotor 30, and this magnetic coupling. Thus, the torque generated in the inner rotor 30 can be transmitted to the outer rotor 20.

  Such a hybrid drive system using the rotating electrical machine 100 of the present embodiment has an output shaft only by driving the engine with high efficiency when, for example, the battery capacity is reduced or the battery is in a very low temperature state. Therefore, the hybrid drive system can be made small and highly efficient.

  In addition, when applied to a range extender type hybrid drive system, for example, the rotating electrical machine 100 of the present embodiment temporarily converts the electric power generated by a conventional generator for generation into a direct current by an inverter and then supplies the converted electric power to the drive motor. Compared to the configuration, energy can be transmitted through a shorter path, the apparatus can be reduced in size and cost, and energy transmission efficiency can be improved.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

  The rotating electric machine 100 of the present embodiment is an inner rotor type having a radial gap structure, but may be an axial gap structure or an outer rotor structure. Moreover, a copper wire, an aluminum conductor, and a litz wire can be used for each coil. The rotating electrical machine 100 can be applied not only to hybrid vehicles but also to other industrial fields such as wind power generators and machine tools.

DESCRIPTION OF SYMBOLS 10 ... Stator 14 ... Armature coil 20 ... Outer rotor (1st rotor)
22 ... Inner salient pole 23 ... Outer salient pole 30 ... Inner rotor (second rotor)
32 ... Rotaries (saliency pole)
33 ... Slot 34 ... Excitation coil 100 ... Rotating electrical machine 100c ... Rotating axis C ... Full wave rectification circuit Iim ... Frequency difference induction coil Is ... Harmonic induction coil WF ... Field coil

Claims (4)

A stator having an armature coil that generates magnetic flux by supplying an alternating current;
A first rotor that is provided closer to the rotating shaft than the stator and rotates at a first frequency by interlinking of the magnetic flux;
A rotating electrical machine having a second rotor that is provided closer to the rotating shaft than the first rotor and rotates at a second frequency different from the first frequency;
The first rotor is
The inner salient pole provided on the side facing the second rotor has a frequency difference induction coil in which a magnetic flux having a frequency difference between the first frequency and the second frequency is linked,
On the radially outer peripheral side of the outer salient pole provided on the side facing the stator, a harmonic induction coil in which harmonics included in the magnetic flux generated in the stator are linked,
A rotating electrical machine comprising a field coil to which current generated by the harmonic induction coil and the frequency difference induction coil is supplied on a radially inner periphery side of the outer salient pole. The first rotor is
2. The rotation according to claim 1, further comprising a full-wave rectifier circuit that rectifies an alternating current generated in the harmonic induction coil and the frequency difference induction coil into a direct current and supplies the direct current to the field coil. Electric. The first rotor is
Rotating at a first frequency synchronized with the frequency of the alternating current supplied to the stator;
The second rotor is
The rotating electrical machine according to claim 1 or 2, wherein the rotating electrical machine rotates at a second frequency that is asynchronous with the first frequency. The second rotor is
4. An excitation coil for generating magnetic flux by secondary excitation, wherein the excitation coil is distributedly wound around a plurality of salient poles each having six times the number of poles. The rotating electrical machine according to any one of the above.