JP2007259630A - Stator structure of rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator structure of a rotary electric machine that can suppress an increase in the number of inverters accompanied by multi-phasing, and accordingly, can suppress cost increase. <P>SOLUTION: The stator structure of the rotary electric machine comprises an m-phase motor, a control means that drives the m-phase motor in terms of an n-phase (n<m). Tooth tips of a stator of the m-phase motor are arranged at unequal pitches so that the real current phase matches the actual current phase. More specifically, the tooth tips are arranged at the unequal pitches, by arranging teeth at equal pitches from a stator core and by deforming tips of the teeth, or by arranging the teeth at unequal pitches from the stator core. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a rotor having a rotor core, a magnet, and a shaft, and a stator having a stator core and a stator coil in which a coil is wound around the stator core, and the rotor is rotatably held by the stator with an air gap. This relates to a stator structure.

  Conventionally, it is common to drive a three-phase motor three-phase with one three-phase inverter. In recent years, in order to improve the output density (maximum output with respect to the volume) of a motor, the driving method has been multiphased. As an example, a technique for driving in nine phases is known (for example, Patent Documents). 1).

JP 2005-39932 A

  In the prior art described above, a nine-phase motor is driven by nine phases with three three-phase inverters, thereby improving the output density. For this reason, the above-described prior art has a problem in that the number of inverters increases as the number of phases increases, and the cost increases.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and to provide a stator structure for a rotating electrical machine that can suppress an increase in the number of inverters associated with multi-phase and consequently suppress an increase in cost. To do.

  A stator structure of a rotating electrical machine according to the present invention includes an m-phase motor and control means for driving the m-phase motor to n-phase (n <m), and the stator of the m-phase motor has an actual current phase that is an ideal current. The teeth tips are arranged at unequal pitches so as to coincide with the phase.

  The present invention includes an m-phase motor and control means for driving the m-phase motor to n-phase (n <m), and the stator of the m-phase motor has a tooth tip so that the actual current phase matches the ideal current phase. Are arranged at unequal pitches, the m-phase motor can be driven in n-phase (n <m), and the increase in the number of inverters associated with multi-phase can be suppressed, resulting in an increase in cost. It is possible to obtain a stator structure of a rotating electrical machine that can suppress the above.

  By the way, if the m-phase motor is driven in n-phase (n <m), the actual current phase becomes unequal pitch. Therefore, if the stator teeth are arranged at equal pitch, the teeth position deviates from the ideal current phase, and the teeth This reduces the rate at which the magnetic flux generated in step 1 is converted to torque (output efficiency is reduced). However, in the present invention, in addition to driving the m-phase motor to n-phase (n <m), the tips of the teeth are arranged at unequal pitches so that the actual current phase matches the ideal current phase. The above-described cost increase is suppressed without deviating from the ideal current phase (without reducing the output efficiency).

  In addition, as a suitable example of the stator structure of the rotating electrical machine of the present invention, the teeth tips may be arranged at unequal pitches by arranging the teeth from the stator core at an equal pitch and deforming the tips of the teeth. With this configuration, and by disposing the teeth from the stator core at an unequal pitch, the tips of the teeth may be disposed at an unequal pitch. In any configuration, the tips of the teeth become unequal pitches, and the present invention can be suitably implemented.

（ここで、Ｐは極対数、Ｓはスロット数）とし、等間隔状態のときのティース間の機械角θmを、

としたとき、３相もしくは３相反転で駆動した時の実電流位相θr_nとの位相差θr_n−θe_nに基づき、回転子の回転方向と逆の方向に、

だけ、ティースの位置を移動する、またはティース先端を傾けた形状とする、ことがある。このように構成することで、具体的に、実電流位相が利用電流位相と一致するよう、ティース先端を不等ピッチで配置させることができる。 Further, preferred examples of a stator structure of the rotary electric machine of the present invention, the ideal current phase .theta.e _n,

(Where P is the number of pole pairs, S is the number of slots), and the mechanical angle θm between the teeth in the equally spaced state,

When a, based on the phase difference θr _n -θe _n between the actual current phase [theta] r _n when driven by 3-phase or three-phase inversion, the direction of rotation opposite to the rotor,

Only the tooth position may be moved, or the tooth tip may be inclined. With this configuration, specifically, the tips of the teeth can be arranged at unequal pitches so that the actual current phase matches the utilization current phase.

  First, the stator structure of the rotating electrical machine of the present invention is characterized in that the tips of the teeth are arranged at unequal pitches so that the actual current phase matches the ideal current phase when the m-phase motor is driven in n-phase (n <m). There is in being. As a specific preferred example, the teeth are arranged from the stator core at an equal pitch and the tips of the teeth are deformed to arrange the teeth at an unequal pitch, or the teeth are arranged from the stator core at an unequal pitch. Thus, the tips of the teeth may be arranged at unequal pitches.

となる。 Normally, when trying to drive an m-phase motor, the distribution coefficient will not be 1 unless the m-phase motor is driven. It cannot be demonstrated and will be reduced. Here, the distribution coefficient is obtained by taking the phase difference between the ideal current phase and the actual current phase in each phase by cos and dividing the sum by the number of slots. That is, the phase difference and θr _n -θe _n, and the number of slots is S, the distribution coefficient,

It becomes.

  In the present invention, as described above, when driving the m-phase motor in the n-phase (n <m), the tips of the teeth are arranged at unequal pitches so that the actual current phase matches the ideal current phase. Thus, the phase difference can be canceled and the distribution coefficient can be made close to 1.

<About the ideal current phase, actual current phase, and phase difference in the case of P pole pair S slot>
FIG. 1 is a diagram showing an example of a development view at a tooth center diameter in an axial gap motor having a P pole pair and an S slot. In the example shown in FIG. 1, the ideal current phase .theta.e _n can be expressed as follows.

<Unequal pitch at teeth tip>
In the motor in the state shown in FIG. 1, the arrangement of the unequal pitches at the tips of teeth can be determined as follows. First, in the state shown in FIG. 1, the mechanical angle θm between the tooth centers can be expressed as follows.

  When driving with the above-mentioned ideal current phase, actual current phase, and mechanical angle by three-phase (reversal) drive, the actual current phase is a multiple of 60 ° of 0 °, 60 °, 120 °,. Select the value closest to the ideal current phase value. However, when the actual current phase is determined under the above conditions for a motor that is originally driven with three or more phases, the current phase angle when driven with the original number of phases cannot be covered. Therefore, in the preferred embodiment of the present invention, the unequal pitches at the tips of the teeth are determined as follows.

だけ、移動させる。
（３）θr_n−θe_n＜０の場合：
ロータ回転方向側にティース先端の位置を

だけ、移動させる。 (1) When θr _n −θe _n = 0:
The position of the teeth tip is not changed.
(2) When θr _n −θe _n > 0:
Position the tip of the teeth on the opposite side of the rotor rotation direction

Just move it.
(3) When θr _n −θe _n <0:
Position the tip of the teeth on the rotor rotation direction side

Just move it.

だけ移動することで、異なっている理想電流位相と実電流位相とを一致させている。対象となるティースにおいて、理想電流位相と実電流位相とが異なる電流位相角である場合は、図２（ｂ）の例となる。 FIGS. 2A and 2B are views showing the relationship between the tip position of the stator teeth and the magnet of the rotor in the initial state and the state after the tooth tip movement, respectively. In the example shown in FIGS. 2A and 2B, an example of an axial gap motor will be described. At the initial position of the tooth tip shown in FIG. 2A, the tooth tips 1-1 to 1-3 are arranged with respect to the magnet 2 at a constant mechanical angle θm between the tooth centers. When the ideal current phase and the actual current phase have the same current phase angle in the target tooth, an example of FIG. On the other hand, after correcting the position of the tooth tip shown in FIG. 2B, the intermediate tooth tip 1-2 in FIG.

The ideal current phase and the actual current phase which are different from each other are made to coincide with each other by moving only by. In the case where the target tooth has a current phase angle that is different from the ideal current phase and the actual current phase, an example of FIG.

<About the first embodiment>
3 to 6 are views for explaining a first embodiment of a stator structure of a rotating electrical machine according to the present invention. The examples shown in FIGS. 3, 5, and 6 show a quarter part of the developed view at the center diameter of the teeth in the axial gap motor including the two rotors 12-1 and 12-2 on both sides of the stator 11. FIG. In the developed view of the ¼ portion, the stator 11 includes coils 13-1 to 13-that are provided by winding the stator teeth 11-1 to 11-9 and the stator teeth 11-1 to 11-9 separately. 9.

  In the example shown in FIG. 3, an ideal current phase, an actual current phase, and a phase difference in each phase in an 8-pole pair 36 slot motor driven by 9 phases are shown. In the nine-phase drive of this example, the current phase difference in each phase is 0 and the distribution coefficient is 1. In addition, in FIG. 3, the winding direction of the coils 13-1 to 13-9 is also shown. FIG. 4 shows the current phase in the nine-phase drive of the motor shown in FIG.

  In the example shown in FIG. 5, an ideal current phase, an actual current phase, and a phase difference in each phase in an 8-pole pair 36 slot motor driven by three-phase inversion are shown. In the figure, the stator teeth with bars on W, U, and V are in a reverse drive phase. In this example, a phase difference occurs depending on the stator teeth, and the distribution coefficient is 0.95975 by taking the phase difference between the ideal current phase and the actual current phase in each phase by cos and dividing this sum by the number of slots. . That is, the distribution coefficient is not 1, and as shown in FIG. 3, when a three-phase drive is performed in a motor in which the nine-phase drive is ideal, the torque is reduced with respect to the nine-phase drive. In addition, in FIG. 5, the winding direction of the coils 13-1 to 13-9 is also shown.

  In the example shown in FIG. 6, an ideal current phase, an actual current phase, and a phase difference in each phase in an 8-pole pair 36 slot motor driven by three-phase inversion are shown. In the figure, the stator teeth with bars on W, U, and V are in a reverse drive phase.

  In this example, in each of the stator teeth 11-2, 11-3, 11-5, 11-6, 11-8, and 11-9 constituting the phase in which the phase difference between the ideal current phase and the actual current phase occurs, The positions of the stator teeth 11-1 to 11-9 are the same as those in the example shown in FIG. 5, and the teeth tip portions 11-2a: 11-2b, 11-3a: 11 at both ends of the stator teeth of the phase having a phase difference. -3b, 11-5a: 11-5b, 11-6a: 11-6b, 11-8a: 11-8b, 11-9a: 11-9b, depending on whether the phase difference is positive or negative with respect to the rotational direction of the rotor The ideal current phase and the actual current phase are made to coincide with each other by inclining by a predetermined angle in a predetermined direction. Specifically, the teeth tip of the phase having a phase difference is inclined in a predetermined direction by an electrical angle of 20 ° and a mechanical angle of 2.5 °.

  By adopting the shape of the tooth tip described above, the phase difference between the ideal current phase and the actual current phase in each phase becomes 0, and the distribution coefficient becomes 1. As a result, torque reduction is suppressed to the same level as in the nine-phase driving example. In addition, in FIG. 6, the winding direction of the coils 13-1 to 13-9 is also shown.

<About the second embodiment>
7 to 9 are views for explaining a second embodiment of the stator structure of the rotating electrical machine according to the present invention. The example shown in FIGS. 7 and 8 is a diagram illustrating a quarter portion of the developed view at the center diameter of the teeth in the axial gap motor including two rotors 12-1 and 12-2 on both sides of the stator 11. . In the developed view of the ¼ portion, the stator 11 includes coils 13-1 to 13-that are provided by winding the stator teeth 11-1 to 11-9 and the stator teeth 11-1 to 11-9 separately. 9.

  In the example shown in FIG. 7, an ideal current phase, an actual current phase, and a phase difference in each phase in an 8-pole pair 36 slot motor driven by three-phase inversion are shown. In the figure, the stator teeth with bars on W, U, and V are in a reverse drive phase. In this example, a phase difference occurs depending on the stator teeth, and the distribution coefficient is 0.95975 by taking the phase difference between the ideal current phase and the actual current phase in each phase by cos and dividing this sum by the number of slots. . That is, the distribution coefficient is not 1, and as shown in FIG. 3, when a three-phase drive is performed in a motor in which the nine-phase drive is ideal, the torque is reduced with respect to the nine-phase drive. In addition, in FIG. 7, the winding direction of the coils 13-1 to 13-9 is also shown. 7 is different from the example shown in FIG. 5 in that the interval between the stator teeth is wider than the interval shown in FIG.

  In the example shown in FIG. 8, an ideal current phase, an actual current phase, and a phase difference in each phase in an 8-pole pair 36 slot motor driven by three-phase inversion are shown. In the figure, the stator teeth with bars on W, U, and V are in a reverse drive phase.

  In this example, the positions of the stator teeth 11-2, 11-3, 11-5, 11-6, 11-8, and 11-9 constituting the phase in which the phase difference between the ideal current phase and the actual current phase has occurred. Each of them is configured to be offset by a predetermined angle in a predetermined direction corresponding to the sign of the phase difference with respect to the rotation direction of the rotor, thereby matching the ideal current phase and the actual current phase. Specifically, the tooth tip of the phase having a phase difference is offset in a predetermined direction by an electrical angle of 20 ° and a mechanical angle of 2.5 °.

  By adopting the above-described tooth offset, the phase difference between the ideal current phase and the actual current phase in each phase becomes 0 and the distribution coefficient becomes 1. As a result, torque reduction is suppressed to the same level as in the nine-phase driving example. In addition, in FIG. 8, the winding direction of the coils 13-1 to 13-9 is also shown.

  For reference, FIG. 9 shows the current phase of the three-phase inversion drive of the motor shown in FIGS. 5 to 8 in the first and second embodiments described above.

<Comparison between the first embodiment and the conventional example>
10 shows an example of nine-phase driving (FIG. 3), an example of three-phase inversion driving (FIG. 5), and an example of three-phase inversion driving by deforming the tip of the tooth according to the first embodiment of the present invention (FIG. 6). ) Is a graph showing the results of torque analysis. From the results shown in FIG. 10, when the nine-phase driving model shown in FIG. 3 is driven in three-phase inversion as shown in FIG. 5, the torque decreases, while the teeth according to the first embodiment of the present invention shown in FIG. In the example in which the tip is deformed, it can be seen that the torque has recovered to near the result of the example of nine-phase driving (FIG. 3). Therefore, according to the present invention, there is almost no decrease in torque even when a motor that requires 9-phase driving is driven in 3 phases, and the increase in the number of inverters due to multi-phase driving can be suppressed. It can be seen that the increase in the number can be suppressed. Needless to say, even in the example (FIG. 8) in which the tooth position according to the second embodiment of the present invention is offset and the three-phase inversion drive is performed, the same result as in the first embodiment described above can be obtained. .

  In the example described above, an example has been shown in which three-phase driving is possible for a motor that normally requires nine-phase driving. However, the number of nine-phase and three-phase here is not limited to that number. The present invention described above can be suitably used when n-phase driving (n <m) is performed for a motor that requires m-phase driving.

  According to the stator structure of the rotating electric machine of the present invention, the m-phase motor and the control means for driving the m-phase motor to n-phase (n <m) are provided. Since the tips of the teeth are arranged at unequal pitches so as to match the phase, the m-phase motor can be driven in n-phase (n <m), so the number of inverters accompanying multi-phase increases. Can be suitably used as a stator structure of a rotating electrical machine that can suppress an increase in cost.

It is a figure which shows an example of the expanded view in the teeth center diameter in the axial gap motor of a P pole pair S slot. (A), (b) is a figure which shows the relationship between the front-end | tip position of a stator tooth and the magnet of a rotor in the state after the initial state and the tooth | tip tip movement, respectively. It is a figure for demonstrating the 1st Example in the stator structure of the rotary electric machine of this invention. It is a figure for demonstrating the electric current phase of 9 phase drive. It is a figure for demonstrating the 1st Example in the stator structure of the rotary electric machine of this invention. It is a figure for demonstrating the specific example of 1st Example in the stator structure of the rotary electric machine of this invention. It is a figure for demonstrating the 2nd Example in the stator structure of the rotary electric machine of this invention. It is a figure for demonstrating the specific example of 2nd Example in the stator structure of the rotary electric machine of this invention. It is a figure for demonstrating the electric current phase of 3 phase inversion drive. Example of 9-phase driving (FIG. 3), example of 3-phase inversion driving (FIG. 5), and example of FIG. 6 in which the tip of the tooth according to the first embodiment of the present invention is deformed to perform 3-phase inversion driving (FIG. 6). It is a graph which shows the analysis result of a torque.

Explanation of symbols

1-1 to 1-3 Teeth part 2 Magnet 11-1 to 11-9 Stator teeth 12-1, 12-2 Rotor 13-1 to 13-9 Coil 11-2a: 11-2b, 11-3a: 11- 3b, 11-5a: 11-5b, 11-6a: 11-6b, 11-8a: 11-8b, 11-9a: 11-9b

Claims (4)

  an m-phase motor and control means for driving the m-phase motor to n-phase (n <m), and the stator of the m-phase motor has a tooth tip not so that the actual current phase matches the ideal current phase. A stator structure for a rotating electric machine, wherein the stator structure is arranged at an equal pitch.   The stator structure for a rotating electrical machine according to claim 1, wherein the teeth tips are arranged at unequal pitches by arranging the teeth from the stator core at an equal pitch and deforming the tips of the teeth.   The stator structure for a rotating electrical machine according to claim 1, wherein teeth are arranged at unequal pitches by arranging the teeth at unequal pitches from the stator core. The ideal current phase θe _n,

(Where P is the number of pole pairs, S is the number of slots), and the mechanical angle θm between the teeth in the equally spaced state,

When a, based on the phase difference θr _n -θe _n between the actual current phase [theta] r _n when driven by 3-phase or three-phase inversion, the direction of rotation opposite to the rotor,

4. The stator structure for a rotating electrical machine according to claim 2, wherein the position of the tooth is moved or the tip of the tooth is inclined. 5.

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