JP2019030058A - Rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine in which switching loss in an inverter can be reduced, and the efficiency of the inverter can be improved.SOLUTION: The rotary electric machine includes a power feeding unit 30 which faces, on at least one end in the axial direction of a rotor 20, the rotor 20 with a space therebetween and feeds power to the rotor 20. The power feeding unit 30 has a power feeding coil 32, and a first capacitor 37 which is connected to the power feeding coil 32. The power feeding coil 32 and the first capacitor 37 form a first resonance circuit 38. The rotor 20 has a rotor core 21, multiple rotor teeth 23 which are arranged at an equal interval in the circumferential direction of the rotor core 21, a rotor coil 22 wound around the rotor core 21 or the rotor teeth 23, and a second capacitor 27 which is connected to the rotor coil 22. The rotor coil 22 and the second capacitor 27 form a second resonance circuit 28.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotating electrical machine.

  As a rotating electrical machine used as a drive source for a vehicle such as a hybrid vehicle or an electric vehicle, there is a winding type induction motor.

  The winding induction motor includes a stator coil in a stator and a rotor coil and a slip ring in a rotor. A wound-winding induction motor normally rotates a rotor by energizing a stator coil and generating an induced current and a magnetomotive force in the rotor coil by electromagnetic induction.

  In some winding induction motors, secondary excitation is performed by supplying an excitation current instead of an induction current from an inverter or the like to a rotor coil via a slip ring. As described above, the winding induction motor that supplies the excitation current for secondary excitation via the slip ring wears the sliding surface of the slip ring and the brush, and therefore periodically performs maintenance such as brush replacement. There was a need.

  On the other hand, a technique described in Patent Document 1 is known as a technique that can eliminate periodic maintenance. The thing of patent document 1 forms the rotation transformer by arrange | positioning a transformer movable part and a transformer fixing | fixed part through a gap in the axial direction of a rotor. Thereby, the thing of patent document 1 can carry out secondary excitation of a rotor coil by non-contact.

JP 2004-032945 A

  However, according to the technique described in Patent Document 1, when the electric power for secondary excitation is transmitted from the outside to the rotor, the current frequency applied to the power sending side of the transformer fixed part and the transformer movable part is set as the rotating magnetic field. , That is, an extremely high frequency of 10 to 1000 times the frequency of the power supplied to the stator coil.

  Therefore, the thing of patent document 1 had the problem that the efficiency of the inverter which supplies the electric power for secondary excitation fell, the control of the inverter became complicated, and the increase in the copper loss in a motor was caused.

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a rotating electrical machine that can reduce switching loss in an inverter and improve the efficiency of the inverter.

  In order to achieve the above object, the present invention provides a cylindrical rotor, a stator facing the rotor with a gap on the radially inner side or radially outer side of the rotor, and at least one of the axial directions of the rotor. A power feeding unit that faces the rotor with a gap and feeds power to the rotor, wherein the stator has a stator coil, and the power feeding unit is connected to the power feeding coil and the power feeding coil. And the power supply coil and the first capacitor form a first resonance circuit, and the rotor includes a rotor core, a plurality of rotor teeth arranged at equal intervals in a circumferential direction of the rotor core, and the rotor core or A rotor coil wound around the rotor teeth, and a second capacitor connected to the rotor coil, the rotor coil and the second capacitor And forming a second resonant circuit.

  According to the present invention, switching loss in an inverter can be reduced, and the efficiency of the inverter can be improved.

FIG. 1 is a configuration diagram of a rotating electrical machine according to an embodiment of the present invention. FIG. 2 is a perspective view of a rotor of a rotating electrical machine according to an embodiment of the present invention. FIG. 3 is a perspective view of a rotor with a part cut away of a rotating electrical machine according to an embodiment of the present invention. FIG. 4 is a perspective view of the second rotor core of the rotor of the rotating electrical machine according to the embodiment of the present invention. FIG. 5 is a perspective view of the first rotor core of the rotor of the rotating electrical machine according to the embodiment of the present invention. FIG. 6 is a connection diagram of a stator coil and a rotor coil of a rotating electrical machine according to an embodiment of the present invention. FIG. 7 is a diagram showing magnetic flux vectors in the rotor at the time of secondary excitation of the rotating electrical machine according to one embodiment of the present invention. FIG. 8 is a view showing a modification of the first capacitor and the second capacitor of the rotating electrical machine according to the embodiment of the present invention. FIG. 9 is a configuration diagram of a rotating electrical machine according to a modification of the present invention.

  A rotating electrical machine according to an embodiment of the present invention includes a cylindrical rotor, a stator that is opposed to the rotor with a gap on a radially inner side or a radially outer side of the rotor, and at least one of the rotor in the axial direction. A stator that includes a stator coil, the power supply unit includes a power supply coil, and a first capacitor that is connected to the power supply coil. The power supply coil and the first capacitor form a first resonance circuit. The rotor includes a rotor core, a plurality of rotor teeth arranged at equal intervals in the circumferential direction of the rotor core, and a rotor coil wound around the rotor core or the rotor teeth. And a second capacitor connected to the rotor coil, and the rotor coil and the second capacitor form a second resonance circuit. Thereby, the rotary electric machine which concerns on one embodiment of this invention can reduce the switching loss in an inverter, and can improve the efficiency of an inverter.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a rotating electrical machine according to an embodiment of the present invention will be described in detail with reference to the drawings.

  In FIG. 1, a rotating electrical machine 1 according to an embodiment of the present invention is an induction motor that can be secondary-excited by supplying power at a slip frequency in a non-contact manner, and has a stator 10 formed in a substantially cylindrical shape, A rotor 20 that is disposed to face the stator 10 inward in the radial direction via an air gap, and a power supply unit 30 that faces at least one of the rotor 20 in the axial direction with a gap and supplies power to the rotor 20. I have. The rotor 20 is supported by a motor case (not shown) so as to be relatively rotatable about the rotation shaft 5 as a rotation center.

  The “radial direction” is a direction orthogonal to the direction in which the rotating shaft 5 extends, and is indicated in the radial direction about the rotating shaft 5. “Outside in the radial direction” means a side far from the rotary shaft 5 in the radial direction, and “inside in the radial direction” means a side close to the rotary shaft 5 in the radial direction.

  The “circumferential direction” indicates a circumferential direction around the rotation axis 5. The “axial direction” indicates a direction in which the rotating shaft 5 extends.

  In FIG. 1, the stator 10 has a stator coil 12. The stator 10 includes a plurality of stator teeth (not shown) and a yoke portion that holds the stator teeth, and a stator coil 12 is wound around the stator teeth. The stator coil 12 is provided corresponding to each phase of the polyphase alternating current. In this embodiment, three-phase alternating current is used, and the stator coil 12 is provided corresponding to the three-phase alternating current W phase, V phase, and U phase.

  An inverter 40 is connected to the stator 10, and a three-phase alternating current is supplied from the inverter 40 to the stator coil 12 of the stator 10. Further, an inverter 50 is connected to a power feeding unit 30 described later, and three-phase alternating current is supplied from the inverter 50 to the power feeding coil 32 of the power feeding unit 30.

  The stator coil 12 generates magnetic flux (armature magnetic flux) by energization. The stator 10 generates a rotating magnetic field that rotates in the circumferential direction when three-phase alternating current is supplied to the stator coil 12. The stator 10 rotates the rotor 20 by interlinking the generated armature magnetic flux with the rotor 20.

  1, 2, and 3, the power feeding unit 30 faces the rotor 20 with a gap on both sides in the axial direction of the rotor 20. The power feeding unit 30 has a power feeding coil 32.

  The power feeding unit 30 includes a power feeding tooth 33 that is wound with a power feeding coil 32 and at least a part of which is made of a magnetic material, and a power feeding yoke 36 that supports the power feeding tooth 33 and is made of a non-magnetic material. In addition, you may comprise all the electric power supply teeth 33 from a nonmagnetic material.

  1, 2, and 3, the rotor 20 includes a rotor core 21, a plurality of rotor teeth 23 arranged at equal intervals in the circumferential direction of the rotor core 21, and a rotor coil 22 wound around the rotor core 21 or the rotor teeth 23. ,have.

  3, 4, and 5, the rotor core 21 includes a first rotor core 21 </ b> A and a second rotor core 21 </ b> B that is a separate member from the first rotor core 21 </ b> A. Two second rotor cores 21B are arranged at the end of the first rotor core 21A in the axial direction. In other words, the rotor core 21 is divided into three parts: a first rotor core 21A and two second rotor cores 21B.

  The first rotor core 21A is made of a laminated electromagnetic steel plate, and the second rotor core 21B is made of a dust magnetic core (SMC: Soft Magnetic Composites). The first rotor core 21A and the second rotor core 21B are magnetically separated.

  Since the first rotor core 21A and the second rotor core 21B are magnetically separated, the magnetic flux interlinking with the second rotor core 21B when the secondary excitation is performed interlinks with the first rotor core 21A, and the first rotor core 21A. It can suppress that an eddy current generate | occur | produces in the surface of each electromagnetic steel plate which comprises. Moreover, it can suppress that the magnetic flux linked with each electromagnetic steel plate of 21 A of 1st rotor cores links with the other electromagnetic steel plate adjacent to this electromagnetic steel plate via the 2nd rotor core 21B formed with a powder magnetic core.

  The first rotor core 21A and the second rotor core 21B are integrated by being held by a nonmagnetic member (not shown) made of resin or the like. Then, in a state where the first rotor core 21A and the second rotor core 21B are integrated, the rotor coil 22 is wound by toroidal winding so as to straddle the first rotor core 21A and the second rotor core 21B.

  As described above, the rotor core 21 is divided into the first rotor core 21A and the second rotor core 21B, and the rotor coil 22 is wound by toroidal winding so as to straddle the first rotor core 21A and the second rotor core 21B. The coil 22 can function as a power receiving coil at the site of the second rotor core 21B, and can function as an induction coil at the site of the first rotor core 21A. That is, the power receiving coil and the induction coil can be shared by one rotor coil 22.

  The rotor teeth 23 are composed of a first rotor teeth 23A provided on the first rotor core 21A and a second rotor teeth 23B provided on the second rotor core 21B. The first rotor teeth 23A face the stator 10 in the circumferential direction with a gap therebetween. The second rotor teeth 23B are opposed to the power feeding unit 30 in the axial direction with a gap therebetween.

  The rotor core 21 is formed with a plurality of groove-like slots 24 for accommodating the rotor coils 22. The slot 24 is formed in a groove shape extending in the axial direction on the outer peripheral surface of the rotor core 21.

  The slot 24 includes a first slot 24A provided in the first rotor core 21A and a second slot 24B provided in the second rotor core 21B. The first slot 24 </ b> A and the second slot 24 </ b> B are aligned in the axial direction in the rotor core 21.

  In FIG. 6, the feeding coil 32 is three-phase star connection (also referred to as three-phase Y connection). A first capacitor 37 is connected in series to the feeding coil 32. A first resonance circuit 38 is formed by the feeding coil 32 and the first capacitor 37 connected to the feeding coil 32. Therefore, the first resonance circuit 38 is a series LC resonance circuit.

  On the other hand, a second capacitor 27 is connected to the rotor coil 22 in series. A rotor coil 22 and a second capacitor 27 connected to the rotor coil 22 form a second resonance circuit 28.

  Therefore, the second resonance circuit 28 is a series LC resonance circuit. The second resonance circuits 28 of each phase are electrically separated from each other. That is, the second resonance circuit 28 of each phase is configured to be in an electrically floating state with a common ground.

  In the present embodiment, the resonance frequency of the first resonance circuit 38, the resonance frequency of the second resonance circuit 28, and the predetermined current frequency of the three-phase alternating current that flows through the power supply coil 32 are substantially the same. The term “substantially coincides” means that they coincide with each other to the extent that they slightly differ by the slip frequency between the stator 10 and the rotor 20.

  Here, in the present embodiment, the three-phase alternating current supplied to the feeding coil 32 has a low frequency of several tens of Hz. Therefore, the resonance frequencies of the first resonance circuit 38 and the second resonance circuit 28 are also set to be a low frequency that substantially matches the three-phase alternating current.

  By doing in this way, the three-phase alternating current supplied to the power supply coil 32 can be supplied to the rotor coil 22 of the rotor 20 by the resonance coupling between the first resonance circuit 38 and the second resonance circuit 28.

  As shown in FIGS. 1, 2, and 3, the rotor 20 is a winding induction rotor in which a rotor coil 22 is toroidally wound around a rotor core 21 so as to have a torus shape that is an annular solid shape.

  In the present embodiment, the power feeding unit 30 is disposed so as to face the rotor 20 in the axial direction. Then, by supplying power from the power feeding unit 30 to the rotor 20 due to magnetic flux fluctuation of the slip frequency by electromagnetic resonance coupling, secondary excitation of the rotor 20 by brushless is realized. Here, brushless refers to supplying electric power in a non-contact manner by electromagnetic coupling instead of supplying electric power at the contact surface between the brush and the slip ring.

  The inductances of the power supply coil 32 and the rotor coil 22 and the capacitances of the first capacitor 37 and the second capacitor 27 are based on the resonance frequency on the power supply unit 30 side and the resonance frequency on the rotor 20 side, and the slip frequency in the normal region of the rotor 20. It is determined so as to resonate at several tens of Hz to several hundreds of Hz.

  By determining each inductance and each capacitance in this way, the resonance frequencies of the first resonance circuit 38 and the second resonance circuit 28 are determined.

  Since both the first resonance circuit 38 and the second resonance circuit 28 are series LC circuits, the impedance can be minimized and the current can be maximized during electromagnetic resonance.

  The secondary excitation power supply unit 30 includes a power supply core 31 made of a non-magnetic PPS (polyphenylene sulfide) resin. The power supply core 31 includes a power supply tooth 33 and a power supply yoke 36. A multi-phase (three-phase) power supply coil 32 is wound around a power supply tooth 33.

  Concentrated winding or distributed winding can be adopted as a method of winding the feeding coil 32. In order to reduce the copper loss in the feeding coil 32, it is desirable that the feeding coil 32 is wound in a concentrated manner.

  As the type of the feeding coil 32, a rectangular wire, a round wire or a litz wire can be adopted. The feeding coil 32 is preferably a litz wire in order to suppress copper loss from occurring in the feeding coil 32 due to the linkage of leakage magnetic flux. On the other hand, the rotor coil 22 is preferably distributed winding.

  With such a configuration, it is possible to perform secondary excitation of the rotor 20 without a brush, and it is possible to realize high robustness and downsizing of the system due to the brushless.

  Here, in order to cause electromagnetic resonance at a low frequency, it is desirable to design with a higher coupling coefficient k instead of a Q factor (Quality Factor).

  In order to increase the coupling coefficient k, it is desirable to increase the magnetic coupling coefficient between the feeding coil 32 and the rotor coil 22 using an iron core (magnetic core), rather than driving at high frequency using an air-core coil.

  Therefore, an auxiliary pole 35 made of a magnetic material is embedded inside the power supply tooth 33. A plurality of auxiliary poles 35 are provided adjacent to each other in the circumferential direction. By providing the auxiliary pole 35, the inductance of the feeding coil 32 and the rotor coil 22 can be improved to facilitate electromagnetic resonance at a low frequency, and the power transmission efficiency when performing secondary excitation by electromagnetic resonance can be improved. Can do.

  The auxiliary pole 35 need not be provided with a magnetic back yoke for forming a closed magnetic path. Even when the back yoke of magnetic material is not provided on the auxiliary pole 35, the low magnetic permeability portion made of resin between the auxiliary poles 35 adjacent in the circumferential direction can be magnetically coupled at a high magnetic flux density during resonance. Is possible.

  In addition, it is good also considering the electric power feeding part 33 as the air-core coil structure, without providing the supplementary pole 35 in the electric power feeding tooth 33. FIG.

  Even when the power feeding unit 30 has an air-core coil structure and the power feeding coil 32 is wound around a power feeding tooth 33 made of only a nonmagnetic material, the power feeding unit 30 and the rotor 20 can be magnetically coupled with a high magnetic flux density. .

  Since magnetic coupling can be performed with a high magnetic flux density, magnetic flux that fluctuates at the slip frequency can be linked to the rotor 20. As a result, the magnetic flux fluctuations are linked to the toroidally wound rotor coil 22 to generate an induction current having a slip frequency, thereby enabling secondary excitation.

  Here, the reason why the power feeding section 30 for secondary excitation has an air-core coil structure is that when the secondary excitation is not performed, leakage magnetic flux is linked to the power feeding section 30 and the torque of the rotor 20 is reduced. This is to prevent it. That is, by making the power feeding unit 30 an air-core coil structure, the magnetic flux can pass in the axial direction only when secondary excitation is performed by electromagnetic resonance coupling.

  The rotor 20 is configured by winding a multi-phase (three-phase) rotor coil 22 around a rotor core 21 that is a magnetic material. The 2nd rotor core 21B has the rotor teeth 23B which oppose the electric power feeding part 30 in an axial direction via a gap. The second rotor teeth 23B are composed of soft magnetic composites (SMC), which are soft magnetic composite materials, in order to form a circumferential and axial three-dimensional magnetic path with the power feeding unit 30. Yes.

  FIG. 7 shows a magnetic flux vector diagram obtained by electromagnetic field analysis when brushless secondary excitation is performed. As shown in FIG. 7, the magnetic flux fluctuation of the slip frequency is linked to the power supply teeth 33 on the axial gap surface of the rotor 20 by the electromagnetic resonance from the secondary excitation power supply section 30 in which the power supply coil 32 is wound around the nonmagnetic material. ing.

  Further, the magnetic flux fluctuations are linked to the power supply coil 32 wound around the power supply tooth 33, so that an induced electromotive force having a slip frequency is generated according to Faraday's law. Therefore, an induced electromotive force having a slip frequency can be obtained on the rotor coil 22, and secondary excitation can be performed brushlessly.

  Further, it is preferable that the first capacitor 37 and the second capacitor 27 are configured to have variable capacitances.

  In the 1st capacitor | condenser 37 and the 2nd capacitor | condenser 27, a capacity | capacitance can be changed by changing the area of the electrode which opposes. Alternatively, in the first capacitor 37 and the second capacitor 27, the capacitance can be changed by changing the distance between the opposing electrodes.

  Alternatively, in the first capacitor 37 and the second capacitor 27, the capacitance can be changed by changing the dielectric constant (or relative dielectric constant) of the dielectric.

  Among the above methods, the method of changing the capacitance by changing the area of the opposing electrodes is, for example, as shown in FIG. 8, a plurality of n capacitors C1, C2,... Cn and the capacitors C1, .., Cn, and capacitors C1, C2,... Cn can be selectively connected in parallel by a combination of opening and closing of the switches S1, S2,.

  Further, when the capacitances of the first capacitor 37 and the second capacitor 27 are changed, the resonance frequencies of the first resonance circuit 38 and the second resonance circuit 28 also change. For this reason, the inverter 50 changes the current frequency which supplies with electricity to the feed coil 32 so that it may correspond with the resonance frequency after a change substantially.

  The inverters 40 and 50 and the switches S1, S2,... Sn are synchronously controlled so as to perform secondary excitation of the rotor 20 at a common resonance frequency that is substantially the same.

  Moreover, the rotary electric machine 1 should just be provided with the stator 10 as a stator, and the rotor 20 as a mover which can move relatively with respect to this stator 10, and is a linear motor type rotary electric machine. Also good.

  As described above, in this embodiment, the cylindrical rotor 20, the stator 10 that faces the rotor 20 with a gap on the radially inner side or the radially outer side of the rotor 20, and at least one of the axial directions of the rotor 20. A power feeding unit 30 that faces the rotor 20 with a gap and feeds power to the rotor 20. The stator 10 has a stator coil 12.

  The power supply unit 30 includes a power supply coil 32 and a first capacitor 37 connected to the power supply coil 32. The feeding coil 32 and the first capacitor 37 form a first resonance circuit 38.

  The rotor 20 includes a rotor core 21, a plurality of rotor teeth 23 arranged at equal intervals in the circumferential direction of the rotor core 21, a rotor coil 22 wound around the rotor core 21 or the rotor teeth 23, and a second connected to the rotor coil 22. And a capacitor 27. The rotor coil 22 and the second capacitor 27 form a second resonance circuit 28.

  As a result, since the electromagnetic resonance / magnetic field resonance action is used, compared to the case where the secondary excitation is performed by the conversion transformer method, when the same power is transmitted, the current frequency of energizing the feeding coil 32 for the secondary excitation Can be reduced. For this reason, the switching loss in an inverter can be reduced and the efficiency of an inverter can be improved.

  In the present embodiment, the product of the inductance of the power feeding coil 32 and the capacitance of the first capacitor 37 is substantially the same as the product of the inductance of the rotor coil 22 and the capacitance of the second capacitor 27.

  In the present embodiment, the resonance frequency of the first resonance circuit 38, the resonance frequency of the second resonance circuit 28, and the predetermined current frequency for energizing the power supply coil 32 are substantially the same.

  Here, in Patent Document 1, the current frequency of the power for secondary excitation is significantly higher than the current frequency of energizing the stator coil. For this reason, when the stator coil is energized, the current frequency (slip frequency) flowing through the rotor coil differs from the current frequency flowing through the rotor coil when secondary excitation is performed.

  For this reason, in the rotor which is a rotating body, in addition to the rotor coil, a power receiving coil for receiving the electric power by the secondary excitation, and a frequency converter for converting the current frequency flowing in the power receiving coil into a slip frequency ( It is necessary to provide a rectifier circuit and a high-frequency power converter. Furthermore, it was necessary to transmit a control signal to this apparatus.

  On the other hand, in the present embodiment, the secondary excitation frequency (current frequency for energizing the power feeding coil) and the current frequency flowing in the stator coil 12 substantially coincide. For this reason, since the current frequency flowing through the rotor coil 22 as the induction coil when the stator coil 12 is energized and the current frequency flowing through the rotor coil 22 as the power receiving coil when the secondary excitation is performed substantially match, the rotor 21 The installation of the frequency converter inside and the transmission of the control signal to this device become unnecessary, and the device and the control configuration are simplified.

  Furthermore, in this embodiment, since the current frequencies flowing in the rotor coil 22 substantially coincide with each other when secondary excitation is performed as described above, the rotor coil 22 is formed on the rotor core 21 in a toroidal toroidal winding, so that the stator coil 12 Thus, the induction coil and the power receiving coil can be used together, and the rotor configuration is simplified.

  In addition, it is possible to prevent the motor output from being restricted in order to avoid a failure of the frequency converter due to a centrifugal force or vibration caused by the rotation of the rotor 20 acting. Further, the rotor coil 22 can be directly secondary-excited to the power supply coil 32.

  Further, in the present embodiment, the power feeding unit 30 includes a power feeding coil 33 around which a power feeding coil 32 is wound, a power feeding tooth 33 made of at least a part of a magnetic material, and a power feeding yoke 36 made of a non-magnetic material that supports the power feeding tooth 33. Have.

Thereby, since at least a part of the power feeding tooth 33 is formed of a magnetic material, the degree of magnetic coupling between the power feeding coil 32 and the rotor coil 22 is increased, and the current that can be transmitted by secondary excitation can be increased.
Further, when the secondary excitation is not performed, the leakage magnetic flux interlinking with the rotor 20 interlinks with the magnetic part of the power feeding tooth 33. In the present embodiment, the power supply yoke 36 is formed of a non-magnetic material, and the leakage magnetic flux interlinking with the power supply teeth 33 cannot be short-circuited to the other power supply teeth 33, so that a reduction in the torque of the rotor 20 can be suppressed.
Moreover, since the magnetic resistance between the electric power feeding teeth 33 and the stator 10 can be increased, magnetic interference between them can be suppressed. Further, the power supply yoke 36 can be reduced in weight.

  In the present embodiment, the power feeding unit 30 includes a power feeding tooth 33 made of a nonmagnetic material around which a power feeding coil 32 is wound, and a power feeding yoke 36 that supports the power feeding tooth 33 and is made of a nonmagnetic material.

  By making the power supply teeth 33 and the power supply yoke 36 nonmagnetic in this way, the leakage magnetic flux linked from the rotor 20 to the power supply unit 30 side when the secondary excitation is not performed is greatly reduced.

  For this reason, it can suppress that the torque of the rotor 20 falls. Further, the power feeding unit 30 can be reduced in weight.

  Further, in this embodiment, the cylindrical rotor 20, the stator 10 that faces the rotor 20 with a gap at least in one of the axial directions of the rotor 20, and the rotor 20 on the radially inner side or radially outer side of the rotor 20. And a power feeding section 30 that faces the rotor 20 and feeds power to the rotor 20. The stator 10 has a stator 10 coil.

  The power supply unit 30 includes a power supply coil 32 and a second capacitor 27 connected to the power supply coil 32. The power supply coil 32 and the second capacitor 27 form a second resonance circuit 28.

  The rotor 20 includes a rotor 20 core, a plurality of rotor teeth 20 arranged at equal intervals in the circumferential direction of the rotor 20 core, a rotor coil 22 wound around the rotor 20 core or the rotor 20 teeth, and a rotor coil 22 And a first capacitor 37 to be connected. The rotor coil 22 and the first capacitor 37 form a first resonance circuit 38.

  As a result, since the electromagnetic resonance / magnetic field resonance action is used, compared to the case where the secondary excitation is performed by the conversion transformer method, when the same power is transmitted, the current frequency of energizing the feeding coil 32 for the secondary excitation Can be reduced. For this reason, switching loss can be reduced in the inverter, and the efficiency of the inverter can be improved.

  Note that the current flowing through the stator coil 12 of the stator 10 is not limited to three phases, and may be multiphase. For example, it can be established in four-phase, five-phase, or two-phase. The rotor coil 22 is preferably a three-phase star connection as in the present embodiment, but may be a squirrel-cage rotor structure.

  Further, the present invention is not limited to the inner rotor-type rotating electrical machine 1 as in the present embodiment, but is an outer rotor-type rotating electrical machine.

  Further, the present invention is not limited to the configuration in which the secondary excitation surface is an axial gap surface. For example, the present invention can be applied to a configuration in which the secondary excitation power supply unit 30 is disposed on the inner side and secondary excitation is performed on the radial gap surface. To establish.

  Further, the present invention is not limited to the secondary excitation from both sides of the axial gap surface, and the present invention can be realized even if the secondary excitation is performed by the axial gap surface on one side.

  Further, as a modification of the rotating electrical machine 1, the present invention is also established when a double rotor type rotating electrical machine 100 shown in FIG. 9 is used. In FIG. 9, the rotating electrical machine 100 includes a stator 110 corresponding to the stator 10 described above, an inner rotor 120 corresponding to the rotor 20 described above, and a power supply unit 130 corresponding to the power supply unit 30 described above.

  The rotating electrical machine 100 includes an outer rotor 160 between the stator 110 and the inner rotor 120.

  The stator 110 includes a stator coil 112 corresponding to the stator coil 12 described above. The inner rotor 120 includes a rotor core 121 and a rotor coil 122 corresponding to the rotor core 21 and the rotor coil 22 described above.

  The outer rotor 160 includes a stator core 161 made of a magnetic material, a permanent magnet 162 embedded on the outer peripheral side of the stator core 161, and a permanent magnet 163 embedded on the inner peripheral side of the stator core 161.

  Here, when the outer rotor 160 rotates, a rotating magnetic field for the inner rotor 120 is generated by the permanent magnet 163 on the inner peripheral side thereof. In this sense, the outer rotor 160 functions in the same manner as the stator 10 described above. Therefore, the outer rotor 160 corresponds to the stator in the present invention.

  An inverter 140 corresponding to the above-described inverter 40 is connected to the stator 110. An inverter 150 corresponding to the aforementioned inverter 40 is connected to the power supply unit 130.

  In the rotating electrical machine 100, when the stator 110 generates a rotating magnetic field, the rotating magnetic field is linked to the permanent magnet 162 of the outer rotor 160, so that the outer rotor 160 rotates synchronously.

  When the outer rotor 160 rotates, a rotating magnetic field generated by the permanent magnet 163 of the outer rotor 160 acts on the inner rotor 120 to generate a magnetomotive force in the rotor coil 122 of the inner rotor 120.

  Thereby, the inner rotor 120 functions as an induction rotor in the induction motor, and rotates with a slip relative to the outer rotor 160. In FIG. 9, the engine 102 is connected to the inner rotor 120, and the transmission 103 is connected to the outer rotor 160.

  In this embodiment, power is received from the power feeding unit 30 to the rotor coil 22, but power can be fed from the rotor coil 22 to the power feeding unit 30 in order to control the amount of current flowing through the rotor coil 22. In this case, the rotor coil 22 also functions as a power transmission unit, and the power feeding unit 30 functions as a power reception unit.

  In this embodiment, the rotor 20 is used as the power feeding unit 30 for secondary excitation, but it can also be used as a second stator for exciting the rotor 20. In this case, when the stator 10 is the first stator, the stator teeth of the stator 10 are the first stator teeth, the yoke portion holding the stator teeth of the stator 10 is the first yoke portion, and the stator coil 12 is the first stator coil. The power supply unit 30 can be configured by using the second stator 30, the power supply coil 32 as the second stator coil 32, the power supply teeth 33 as the second stator teeth 33, and the power supply yoke 36 as the second yoke portion. In this case, it is not always necessary to form the first and second capacitors and the first and second resonance circuits. The first rotor core 21A and the second rotor core 21B can also be used as a dust core or a laminated steel plate having an integral structure. Further, the motor structure is not limited to the induction machine, and may be used as, for example, an AC motor using a permanent magnet. The coil 22 is not necessary.

  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.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 10 Stator 12 Stator coil 20 Rotor 21 Rotor core 22 Rotor coil 23 Rotor teeth 27 Second capacitor 28 Second resonance circuit 30 Feeding part 32 Feeding coil 33 Feeding tooth 36 Feeding yoke 37 First capacitor 38 First resonance circuit

Claims (6)

A cylindrical rotor;
A stator facing the rotor with a gap at a radially inner side or a radially outer side of the rotor;
A power feeding part that feeds power to the rotor, facing the rotor with a gap at least in one of the axial directions of the rotor,
The stator is
Having a stator coil,
The power feeding unit is
A feeding coil;
A first capacitor connected to the power supply coil,
The feeding coil and the first capacitor form a first resonance circuit,
The rotor is
Rotor core,
A plurality of rotor teeth arranged at equal intervals in the circumferential direction of the rotor core;
A rotor coil wound around the rotor core or the rotor teeth;
A second capacitor connected to the rotor coil,
A rotating electrical machine, wherein the rotor coil and the second capacitor form a second resonance circuit. The product of the inductance of the feed coil and the capacitance of the first capacitor;
2. The rotating electrical machine according to claim 1, wherein a product of an inductance of the rotor coil and a capacitance of the second capacitor substantially matches.   The resonance frequency of the first resonance circuit, the resonance frequency of the second resonance circuit, and a predetermined current frequency for energizing the power supply coil substantially coincide with each other. Rotating electric machine. The power feeding unit is
The power supply coil is wound, and at least a part of the power supply tooth made of a magnetic material,
The rotating electrical machine according to any one of claims 1 to 3, further comprising: a power supply yoke that supports the power supply teeth and is made of a nonmagnetic material. The power feeding unit is
The feeding coil is wound, and a feeding tooth made of a non-magnetic material,
The rotating electrical machine according to any one of claims 1 to 3, further comprising: a power supply yoke that supports the power supply teeth and is made of a nonmagnetic material. A cylindrical rotor;
A stator facing the rotor with a gap at least in one of the axial directions of the rotor;
A power feeding section that feeds power to the rotor, facing the rotor with a gap on the radially inner side or radially outer side of the rotor,
The stator is
Having a stator coil,
The power feeding unit is
A feeding coil;
A first capacitor connected to the power supply coil,
The feeding coil and the first capacitor form a first resonance circuit,
The rotor is
Rotor core,
A plurality of rotor teeth arranged at equal intervals in the circumferential direction of the rotor core;
A rotor coil wound around the rotor core or the rotor teeth;
A second capacitor connected to the rotor coil,
A rotating electrical machine, wherein the rotor coil and the second capacitor form a second resonance circuit.

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