JP2015163028A - Pole number change rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pole number change rotary electric machine that can reduce iron loss by reducing the number of poles by pole number change during operation at a high-speed rotation region, can reduce torque pulsation, output pulsation, and cogging torque by increasing the number of poles by pole number change during operation at a low-speed rotation region, and does not require coil switchover.SOLUTION: The present invention is a pole number change rotary electric machine 1 in which the number of slots 12 of a stator armature iron core 11 is a fractional slot, and which can change the number of poles by the number of particular fractional slots and the number of poles of a revolving magnetic field without switching connection of armature coils 13, and does not need to switch coils. An armature 10 has coil arrangement of forming a revolving magnetic field having a plurality of the numbers of poles which are the number of slots±1, and the number of slots±1+the number of slots×2×n (n is a positive integer).

Description

  The present invention relates to a pole conversion rotating electrical machine that does not require winding switching.

  Due to environmental and energy issues, plug-in hybrid vehicles and electric vehicles are rapidly being put into practical use, and there is a need for low power consumption, high output, and high efficiency motors in all operating areas. Rare earth element permanent magnets generate a magnetic force several tens of times that of conventional magnets, so that a high output and high efficiency motor can be obtained. In such a motor, in order to drive the motor in the middle to high speed rotation range under the limitation of the power supply voltage, inverter control is used to form a magnetic force in the opposite direction to the magnetic force (magnetic flux) of the permanent magnet, which is called weak magnetic flux control. The magnetic force (voltage) is controlled. The embedded permanent magnet motor (IPM motor) is a permanent magnet motor having a magnetic structure in which this control is effective.

  However, when the variable speed operation is performed by the magnetic flux weakening control, the iron loss is remarkably increased and the efficiency is lowered because the motor is driven by the high frequency voltage in the high speed rotation range. In the low-speed rotation region, torque pulsation, output pulsation, and cogging torque (holding torque at no load) become problems. For example, in a motor for driving an automobile, when starting a hill or driving slowly, a wind power generator has problems such as cogging torque at start-up and output pulsation during power generation at low speed.

Kazuhito Tsuji and Shigeaki Yuzawa, “Basic Research on Pole Conversion Magnet Motor without Winding Switching”, 2013 Annual Conference of the Institute of Electrical Engineers of Japan, 5-008 (2013) Edited by Nobuyuki Matsui, “Reduced Rare Earth / Derare Earth Motor”, Nikkan Kogyo Shimbun (2013)

  The present invention has been made in view of the problems of the prior art as described above. For operation in the high-speed rotation range, iron loss can be reduced by reducing the number of poles by pole conversion, and in the low-speed rotation range. It is an object of the present invention to provide a pole number-converting rotating electrical machine that does not require coil switching and can reduce torque pulsation, output pulsation, and cogging torque by increasing the number of poles by pole number conversion.

  The present invention relates to a coil switching method in which the number of slots of the stator armature core is a fractional slot and the number of poles can be changed without switching the connection of the armature windings with a specific number of fractional slots and the number of poles of the rotating magnetic field. Features an unnecessary pole conversion rotating electrical machine.

  The present invention also includes an armature composed of an armature core having an odd number of slots that is a multiple of three, an armature winding around which a conductor in the slot is wound, and a rotor disposed in the armature. The armature is a pole number conversion rotating electrical machine having a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers of slot number ± 1, slot number ± 1 + slot number × 2 × n (n is a positive integer). Features.

  The present invention further includes an armature including an armature core having an even number of slots that is a multiple of three, an armature winding having a conductor wound in the slot, and a rotor disposed in the armature. The armature is a pole number conversion rotating electric machine having a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers of slot number ± 2, slot number ± 2 + slot number × 2 × n (n is a positive integer). Features.

  According to the present invention, the pole number can be converted without switching the connection of the armature winding, the iron loss can be reduced by reducing the number of poles by the pole number conversion at high speed rotation, and more at the low speed rotation. By converting to a large number of poles, torque pulsation, output pulsation, and cogging torque can be reduced.

Sectional drawing of the permanent magnet motor of the 1st Embodiment of this invention. Sectional drawing which shows the coil | winding (coil) arrangement | positioning of the permanent magnet motor of the said 1st Embodiment. FIG. 3 is an explanatory diagram of specifications of the permanent magnet motor according to the first embodiment. Explanatory drawing of winding (coil) arrangement | positioning AD used for the analysis of the permanent magnet motor of Example 1. FIG. Explanatory drawing which shows the correspondence of the number of poles used for the analysis of the permanent magnet motor of Example 1, and winding (coil) arrangement | positioning. 6 is a graph of an average torque analysis result of the permanent magnet motor of Example 1. The graph of the torque ripple analysis result of the permanent magnet motor of Example 1. FIG. Sectional drawing of the permanent magnet motor of the 2nd Embodiment of this invention. Sectional drawing which shows winding (coil) arrangement | positioning of the permanent magnet motor of the said 2nd Embodiment. FIG. 9 is an explanatory diagram of specifications of the permanent magnet motor according to the second embodiment. Explanatory drawing of winding (coil) arrangement | positioning AD used for the analysis of the permanent magnet motor of Example 2. FIG. Explanatory drawing which shows the correspondence of the number of poles used for the analysis of the permanent magnet motor of Example 2, and winding (coil) arrangement | positioning. 6 is a graph of an average torque analysis result of the permanent magnet motor of Example 2. The graph of the torque ripple analysis result of the permanent magnet motor of Example 2. FIG. Sectional drawing of the permanent magnet motor of the 3rd Embodiment of this invention. Sectional drawing which shows winding (coil) arrangement | positioning of the permanent magnet motor of the said 3rd Embodiment. FIG. 9 is an explanatory diagram of specifications of the permanent magnet motor of the third embodiment. Explanatory drawing of winding (coil) arrangement | positioning AE used for the analysis of the permanent magnet motor of Example 3. FIG. Explanatory drawing which shows the correspondence of the number of poles used for the analysis of the permanent magnet motor of Example 3, and winding (coil) arrangement | positioning. 10 is a graph of an average torque analysis result of the permanent magnet motor of Example 3. 10 is a graph of torque ripple analysis results of the permanent magnet motor of Example 3.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
The pole conversion rotating electrical machine according to the first embodiment shown in FIG. 1 is composed of an armature core 11 having an odd number of slots that is a multiple of 3 and an armature winding 13 around which a conductor in the slot 12 is wound. The armature 10 is provided with a permanent magnet type rotor 20 disposed in the armature 10, and the armature 10 has the number of slots ± 1, the number of slots ± 1 + the number of slots × 2 × n (n is a positive number) This is a permanent magnet motor 1 with a pole number conversion in a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers.

  Here, in the first embodiment shown in FIG. 1, the number of slots 12 of the armature core 11 is nine slots as an odd number that is a multiple of three. Further, the winding arrangement is as shown in FIG. 2. By adopting such a winding arrangement, 8 poles, 10 poles (slot number ± 1), 26 poles, 28 poles (n = 1, number of slots) ± 1 + slot number x 2), 44 poles, 46 poles (n = 2, slot number ± 1 + slot number x 4) Winding conductors 13U, 13W, and 13V are arranged in this phase order.

  The rotor 20 receives on the surface of the rotor core 22 a low coercive force permanent magnet 21 in which a portion receiving the external magnetic field is instantaneously magnetized irreversibly in the direction of the magnetic field. It is a fixed surface magnet type configuration.

  In the permanent magnet motor 1 having such a configuration, an instantaneous pulse current is passed through the armature winding 12 and the permanent magnet 21 is magnetized by a magnetic field generated by the current to form a magnetic pole corresponding to the magnetic field.

  As a result, the permanent magnet motor 1 can generate an output by rotating the same number of rotating magnetic poles as the magnetic poles of the permanent magnet 21 in synchronization. At this time, the driving is performed synchronously at a rotational speed close to a rotating magnetic field determined by the frequency and the number of poles when the number of poles is converted. Or if it comprises as follows, it will be reliably magnetized by the pole number, and it can drive by pole number conversion. The number of poles in the multipole with a large number of poles and the number of poles with a smaller number of poles, the same number of permanent magnets as the number of poles with a large coercive force (the magnetization of the permanent magnet by the magnetic field generated by the armature current) Is a permanent magnet with a coercive force that does not change, and is called a fixed-magnet magnet here. The permanent magnet has a low coercive force (a magnetic field generated by an armature current). A variable magnetic force magnet having a coercive force enough to change the magnetization of the permanent magnet is disposed. In the case of 8 poles, an 8-pole d-axis magnetic field is formed at an angle that is shifted in phase by an angle that is the opposite phase of 26 poles if the pre-conversion is 26 poles with reference to the 8-pole d-axis direction. An armature current for magnetizing is applied. As a result, eight magnetic poles can be formed on the rotor 20. Conversely, when changing from 8 poles to 26 poles, a magnetic field is formed at a position that is further shifted by a phase that is in phase with the 26 poles with reference to the phase of the armature current that forms a magnetic field that is opposite in phase to the 8 poles. Thus, the phase of the armature current is determined and the armature current is supplied from the inverter to magnetize the rotor magnet. Since only the variable magnetic magnet changes, 26 poles can be formed on the rotor.

  Instead of such a surface permanent magnet type, an embedded permanent magnet type configured by embedding the low coercivity permanent magnet 21 in the rotor core 22 may be employed. In addition, when the stator armature 10 used in the above embodiment is applied to an induction machine, a copper bar is inserted into the rotor core and the slots of the rotor core instead of the permanent magnet type rotor 20 having the above configuration. A magnetic pole variable rotating electrical machine can be configured by using a rotor configured as described above. The pole number conversion of the induction machine tries to operate at a rotation speed at which slip near a rotating magnetic field determined by the frequency and the number of pole conversion is small. Therefore, the pole number can be automatically converted by determining the frequency so that the operating point of the small slip as described above is obtained for an arbitrary rotation number.

  With respect to the surface magnet type motor having the specifications shown in FIG. 3, the winding arrangement for obtaining the number of poles of 2 to 48 poles was obtained. FIG. 4 shows the winding arrangements A to D, and FIG. 5 shows the correspondence between the number of poles and the winding arrangement for obtaining the number of poles. A magnetic field analysis of basic characteristics was performed on the surface magnet type motor having each pole number.

  18 poles and 36 poles could not be configured as a three-phase motor. Regarding the other pole numbers, the fifth and seventh harmonics decreased as the number of poles increased. FIG. 6 shows average torque, and FIG. 7 shows torque ripple. The number of poles with a large average torque is 8 and 10. The number of poles with a small torque ripple (pulsation component) is 26 and 28. The number of poles with a large generated torque and a small torque ripple is 8, 10, 26, 28, 44, and 46 poles. All of these pole numbers are the winding arrangement D. From this, it was found that the arrangement D has good characteristics of average torque and torque ripple. The 6-pole and 12-pole have a large torque, but the torque ripple is also large, so the characteristics as a motor are not good.

  In this way, a plurality of combinations of the number of poles that can be operated with the same winding arrangement from 2 to 48 poles were confirmed. From this result, the possibility of a permanent magnet motor capable of changing the number of poles without switching the winding was confirmed. It was also found that torque ripple can be greatly reduced by pole number conversion.

[Second Embodiment]
FIG. 8 shows a pole conversion rotating electrical machine according to the second embodiment. The pole conversion rotating electrical machine of the present embodiment includes an armature 10 including an armature core 11 having an even number of slots that is a multiple of 3 and an armature winding 13 having a conductor wound in the slot 12, and an armature. 10, and the armature 10 is rotated by a plurality of poles of slot number ± 2, slot number ± 2 + slot number × 2 × n (n is a positive integer). A permanent magnet motor 1A having a winding arrangement for forming a magnetic field.

  In the case of this embodiment, the number of slots 12 of the armature core 11 is an even number of slots that is a multiple of 3 and is 12 slots. Further, the winding arrangement is as shown in FIG. 9. By adopting such a winding arrangement, 10 poles, 14 poles (slot number ± 2), 34 poles, 38 poles (n = 2, number of slots) The three-phase winding conductors 13U, 13W, and 13V are arranged in this phase order so that the three-phase arrangement is within the 60 ° phase band of each phase with respect to ± 2 + slot number × 2).

  The rotor 20 also has a low coercive force permanent magnet 21 whose portion receiving the external magnetic field is irreversibly magnetized in the direction of the magnetic field by instantaneously receiving a large external magnetic field. It is the structure of the surface magnet type fixed to.

  Even in the permanent magnet motor 1A having such a configuration, as in the first embodiment, an instantaneous pulse current is applied to the armature winding 12, and the permanent magnet 21 is magnetized by the magnetic field generated by the current. Form magnetic poles.

  As a result, the permanent magnet motor 1 can generate an output by rotating the same number of rotating magnetic poles as the magnetic poles of the permanent magnet 21 in synchronization.

  Even in the present embodiment, the low coercivity permanent magnet 21 is embedded in the rotor core 22 in place of the surface permanent magnet type as in the first embodiment. An embedded permanent magnet type can also be employed. Further, when the stator armature 10 used in the present embodiment is applied to an induction machine, a copper bar is inserted into the rotor core and the slots of the rotor core instead of the permanent magnet type rotor 20 having the above configuration. A magnetic pole variable rotating electrical machine can be configured by using a rotor configured as described above.

  For the surface magnet type motor having the specifications shown in FIG. 10, the winding arrangement for obtaining the number of poles of 2 to 48 poles was obtained. FIG. 11 shows the winding arrangements A to D, and FIG. 12 shows the correspondence between the number of poles and the winding arrangement for obtaining the number of poles.

  A magnetic field analysis of basic characteristics was performed on the surface magnet type motor having each pole number. Six poles and multiple poles thereof could not be configured as a three-phase motor. FIG. 13 shows the average torque, and FIG. 14 shows the torque ripple. The number of poles with a large average torque is 10 poles, 14 poles and 16 poles, and the number of poles with a small torque ripple is 34 poles and 38 poles. Among these, the number of poles of 10 poles, 14 poles, 34 poles and 38 poles is the winding arrangement D. From this, it was found that the arrangement D has good characteristics of average torque and torque ripple. Although the 16 poles have a large torque, the torque ripple is also large, so the characteristics as a motor are not good.

  Thus, also in Example 2, a plurality of combinations of the number of poles that can be operated with the same winding arrangement from 2 to 48 poles were confirmed. From this result, the possibility of a permanent magnet motor capable of changing the number of poles without switching the winding was confirmed. It was also found that torque ripple can be greatly reduced by pole number conversion.

[Third Embodiment]
FIG. 15 shows a pole conversion rotating electrical machine according to the third embodiment. The pole conversion rotating electrical machine according to the present embodiment includes an armature 10 including an armature core 11 having an odd number of slots that is a multiple of 3 and an armature winding 13 having a conductor wound in the slot 12, and an armature. 10, and the armature 10 rotates at a plurality of poles of slot number ± 1, slot number ± 1 + slot number × 2 × n (n is a positive integer). This is another permanent magnet motor 1B having a winding arrangement for forming a magnetic field.

  Here, in the embodiment of FIG. 15, the number of slots 12 of the armature core 11 is set to 15 slots as an odd number that is a multiple of 3. Further, the winding arrangement is as shown in FIG. 16. By adopting such a winding arrangement, 14 poles, 16 poles (slot number ± 1), 44 poles, 46 poles (n = 1, number of slots) The three-phase winding conductors 13U, 13W, and 13V are arranged in this phase order so that the three-phase arrangement is within the 60 ° phase band of each phase with respect to ± 1 + slot number × 2).

  The rotor 20 receives on the surface of the rotor core 22 a low coercive force permanent magnet 21 in which a portion receiving the external magnetic field is instantaneously magnetized irreversibly in the direction of the magnetic field. It is a fixed surface magnet type configuration.

  In the permanent magnet motor 1B having such a configuration, an instantaneous pulse current is supplied to the armature winding 12, and the permanent magnet 21 is magnetized by a magnetic field generated by the current, thereby forming a magnetic pole corresponding to the magnetic field.

  Thereby, this permanent magnet motor 1B can generate an output by rotating the same number of magnetic poles of the rotating magnetic field as the magnetic poles of the permanent magnet 21 in synchronization.

  Instead of such a surface permanent magnet type, an embedded permanent magnet type configured by embedding the low coercivity permanent magnet 21 in the rotor core 22 may be employed. In addition, when the stator armature 10 used in the above embodiment is applied to an induction machine, a copper bar is inserted into the rotor core and the slots of the rotor core instead of the permanent magnet type rotor 20 having the above configuration. A magnetic pole variable rotating electrical machine can be configured by using a rotor configured as described above.

  With respect to the surface magnet type motor having the specifications shown in FIG. 17, the winding arrangement for obtaining the number of poles of 2 to 48 poles was obtained. FIG. 18 shows the winding arrangements A to E, and FIG. 19 shows the correspondence between the number of poles and the winding arrangement for obtaining the number of poles. A magnetic field analysis of basic characteristics was performed on the surface magnet type motor having each pole number. Six poles and multiple poles thereof could not be configured as a three-phase motor.

  FIG. 20 shows average torque, and FIG. 21 shows torque ripple. The number of poles with a large average torque is 14 or 16, and the number of poles with a small torque ripple is 44 or 46. All of these pole numbers are the winding arrangement E. From this, it was found that the winding arrangement E had good characteristics of average torque and torque ripple. The 10 poles and 20 poles have large torque, but the torque ripple is also large, so the characteristics as a motor are not good.

  In this way, a plurality of combinations of the number of poles that can be operated with the same winding arrangement from 2 to 48 poles were confirmed. From this result, the possibility of a permanent magnet motor capable of changing the number of poles without switching the winding was confirmed. It was also found that torque ripple can be greatly reduced by pole number conversion.

  In the pole number conversion of the present invention, when the number of poles of a small pole and a multipole is compared, the number of poles of the multipole is larger than the number of poles by a multiple of 2 of the number of slots. Therefore, the pole number ratio between the small pole and the multi pole in the pole number conversion can be adjusted by the number of slots. If the pole conversion ratio is to be reduced, the number of slots per pole per phase is set to 1/2 or less, and if the pole conversion ratio is to be increased, it is set to 1 or less. In addition, when the number of slots per pole per phase is 1 or more, the integer part of the number of slots (fractional groove) per pole per phase of the present invention is only 1 or more, and the integer part is excluded. The fractional part (the exact fraction) becomes the same as that of the present invention, and the evaluation may be performed with this fractional part.

  As described above, according to the present invention, the armature including the armature core having an odd number of slots that is a multiple of 3 and the armature winding in which the conductor in the slot is wound, and the rotor disposed in the armature And the armature is a pole conversion rotation having a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers of slot number ± 1, slot number ± 1 + slot number × 2 × n (n is a positive integer) An armature comprising an armature core having an even number of slots equal to a multiple of 3; an armature winding having a conductor wound in the slot; and a rotor disposed in the armature. For the pole number conversion rotating electrical machine having a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers of slot number ± 2, slot number ± 2 + slot number × 2 × n (n is a positive integer), A combination of large and small number of poles that can convert the number of poles without switching the line, resulting in a large average torque A combination of a small number of poles that can be made and a large number of poles that can reduce the torque ripple can be achieved, a necessary torque can be output, and a pole conversion rotating electrical machine that can significantly reduce torque ripple by pole number conversion can be realized.

  The pole conversion rotating electrical machine of the present invention can be used for a hybrid vehicle, an electric vehicle, and a railway as a transportation system, can be used for wind power generation and ocean current power generation as an energy system, and can be used for household appliances such as an elevator and an air conditioner as a social system.

1, 1A, 1B Permanent magnet motor 10 Armature 11 Armature core 12 Slot 13 Winding 20 Rotor 21 Permanent magnet 22 Rotor core

Claims (10)

An armature composed of an armature core having an odd number of slots that is a multiple of 3 and an armature winding wound with a conductor in the slot; and a rotor disposed in the armature;
The number of poles is characterized in that the armature has a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers of slot number ± 1, slot number ± 1 + slot number × 2 × n (n is a positive integer). Conversion rotating electrical machine. An armature composed of an armature core having an even number of slots that is a multiple of 3; an armature winding having a conductor wound in the slot; and a rotor disposed in the armature;
The armature has a winding arrangement that forms a rotating magnetic field having a plurality of pole numbers of slot number ± 2, slot number ± 2 + slot number × 2 × n (n is a positive integer). Conversion rotating electrical machine.   3. The number-of-poles rotating electrical machine according to claim 1 or 2, wherein the number of slots per number of poles per phase when the number of slots becomes more multi-pole ± 1 + number of slots × 2 × n (n is a positive integer). A pole number conversion rotating electrical machine characterized in that the number is 1 or less.   3. The number-of-poles rotating electrical machine according to claim 1 or 2, wherein the number of slots per number of poles per phase when the number of slots becomes more multi-pole ± 1 + number of slots × 2 × n (n is a positive integer). Is a pole number conversion rotating electrical machine characterized in that it is reduced to 1/2 or less.   5. The pole conversion rotating electrical machine according to claim 1, wherein the rotor includes a conductor and an iron core, and is used as a pole conversion induction machine.   5. The pole conversion rotating electric machine according to claim 1, wherein the rotor is composed of a permanent magnet and an iron core, and is used as a pole converting permanent magnet rotating electric machine. Electric.   7. The pole number conversion rotating electrical machine according to claim 1, wherein the number of poles of the rotor is varied by magnetizing the permanent magnet with an external magnetic field.   The pole number conversion rotating electrical machine according to claim 1, wherein the permanent magnet is magnetized by a magnetic field generated by an armature current to vary the number of poles of the rotor. Pole conversion rotating electrical machine.   The pole conversion rotating electric machine according to any one of claims 1 to 8, wherein a multi-pole with a large number of poles is operated in a low-speed rotation range, and the operation is performed with a smaller number of poles in a high-speed rotation range. Electric.   In the pole conversion rotating electrical machine according to any one of claims 1 to 9, a multi-pole with a large number of poles is provided in an operation region where torque pulsation or cogging torque is required to be small, and a smaller number of poles in an operation region other than the above. A pole conversion rotating electrical machine characterized by operating with a number.

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