JP2015226425A - Method for driving pole changing type induction machine, and pole changing type induction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for driving a pole changing type induction method, and a pole changing type induction machine, that are excellent in high torque generation by achieving such a coil structure that a coil coefficient at a high polarity becomes a maximum of 1.SOLUTION: Provided is a method for driving a pole changing type induction machine that is executed by a general controller in a pole changing type induction machine comprising the general controller for driving and controlling two three-phase inverters, and in which stator coils each wound by distribution for three-phase driving are alternately connected with the two three-phase inverters every other pole pair, and a distribution winding coefficient kat a time when the number of slots for each pole and for each phase at a high polarity is defined as q is represented by k=sin(π/6)/(q×sin(π/6q)). The method includes a step of performing pole changing so that an inter-group phase difference between the two three-phase inverters becomes low polarity at 0° and becomes high at 180° within a range from 0° to 180°, at the general controller.

Description

  The present invention relates to an alternator / generator used for an existing vehicle, a drive motor used for an electric vehicle, a hybrid vehicle, and the like, and in particular, to increase the number of poles of an induction machine in order to extend the driveable range such as higher torque and higher output. The present invention relates to a method of driving a pole-switching induction machine that is switched and driven, and a pole-switching induction machine.

  Some induction machines used in alternators / generators of existing vehicles, electric vehicles, hybrid vehicles, etc. are driven by switching the number of poles in order to ensure high torque and high output characteristics over a wide rotation range.

  As such a conventional pole number switching type induction machine, the winding configuration of the induction motor has two independent sets of single-layer concentric winding and two-layer lap winding, and has six lead terminals in three phases. (For example, refer to Patent Document 1). In the control of two inverters by the inverter control device of Patent Document 1, the operation is performed in a high pole state where the output phases are the same at a low speed range below the low output range, and the mutual phases are 180 degrees in the high speed range. By operating in an inverted low pole state, the pole number of the induction machine is converted.

  Further, as another conventional pole number switching type induction machine, six coils are arranged every 60 °, and coils facing each other are connected so as to have the same polarity to each other. There exists what was comprised as a coil | winding (for example, refer patent document 2). In the drive method of Patent Document 2, the number of poles of the induction machine is converted by switching the phase sequence of the power supply voltage applied to the terminals of the rotating electrical machine having the three sets of three-phase windings configured as described above. Yes.

JP 7-336971 A JP 11-18382 A

However, the prior art has the following problems.
In the driving method of the pole number switching type induction machine of Patent Document 1 and Patent Document 2, the winding is limited to a single-layer concentric winding, a two-layer lap winding, or a winding structure equivalent thereto. As a result, the upper limit value of the winding coefficient at the time of high pole is less than 1, and there is a problem that more current is required when generating high torque.

  The present invention has been made to solve the above-described problems, and has a number of poles excellent in generating high torque by adopting a winding structure in which the winding coefficient at the time of high pole is a maximum of 1. It is an object of the present invention to obtain a switching type induction machine driving method and a pole number switching type induction machine.

In the method for driving a pole-switching induction machine according to the present invention, stator coils wound in a distributed winding for three-phase driving are alternately connected to two three-phase inverters every other pole pair, The distributed winding coefficient k _wd, where q is the number of slots per phase per pole at high pole time,
k _wd = sin (π / 6) / (q × sin (π / 6q))
A pole number switching type induction machine having an overall control unit that drives and controls two three-phase inverters, and is a method of driving the pole number switching type induction machine that is executed by the overall control unit. Part having a step of switching the number of poles so that the phase difference between the groups of the two three-phase inverters is in the range of 0 ° to 180 °, low pole at 0 ° and high pole at 180 ° It is.

Further, in the pole number switching type induction machine according to the present invention, stator coils wound by distributed winding for three-phase drive are alternately connected to two three-phase inverters every other pole pair. A pole-switching induction machine having an overall control unit that drives and controls three 3-phase inverters, wherein the overall control unit has a phase difference between the two inverters in the range of 0 ° to 180 °, When the number of poles is switched so that the low pole is at 0 ° and the high pole is at 180 °, and the distributed winding has q as the number of slots per pole per phase when the inter-group phase difference becomes a high pole The distributed winding coefficient k _wd of
k _wd = sin (π / 6) / (q × sin (π / 6q))
It is comprised so that it may become.

  According to the present invention, the winding coefficient is set so that the winding coefficient at the time of high pole becomes the formula (1) described later, and the number of poles is switched by changing the phase difference between the groups of the two inverters. . As a result, the winding coefficient at the time of high pole becomes 1 at the maximum, and it becomes possible to increase the winding coefficient at the time of high pole. It has a great effect.

It is a schematic diagram which shows the wiring connection method in the pole number switching type induction machine and inverter which concern on Embodiment 1 of this invention. It is sectional drawing which shows the coil phase order at the time of the low pole of the drive method of the pole number switching type induction machine which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the coil phase sequence at the time of the high pole of the drive method of the pole number switching type induction machine which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the magnetomotive force waveform at the time of the high pole in the drive method of the pole number switching type induction machine which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the magnetomotive force waveform at the time of the low pole in the drive method of the pole number switching type induction machine which concerns on Embodiment 1 of this invention. It is sectional drawing of the induction machine which implement | achieves the pole number switching of 4 poles and 8 poles in the drive method of the pole number switching type induction machine which concerns on Embodiment 2 of this invention. It is a 1st figure which shows the torque characteristic at the time of 4 poles and 8 poles in the drive method of the pole number switching type induction machine which concerns on Embodiment 2 of this invention. It is a 2nd figure which shows the torque characteristic at the time of 4 poles and 8 poles in the drive method of the pole number switching type induction machine which concerns on Embodiment 2 of this invention.

  Hereinafter, preferred embodiments of a method for driving a pole-switching induction machine and a pole-switching induction machine according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated about the part which is the same or it corresponds in each figure.

Embodiment 1 FIG.
Constitution.
FIG. 1 is a schematic diagram showing a wiring connection method between a pole-switching induction machine 1 and inverters 2 and 3 according to Embodiment 1 of the present invention. The induction machine 1 shown in FIG. 1 is connected to two inverters 2 and 3, and the inverters 2 and 3 are both three-phase drive inverters.

  The induction machine 1 has six stator winding outlets U1, V1, W1, U2, V2, and W2. Each stator winding of the induction machine 1 is connected to the phase of the inverters 2 and 3 of the corresponding group. Wired. That is, the group of U1, V1, and W1 is connected to the inverter 2, and the group of U2, V2, and W2 is connected to the inverter 3. U1, V1 and W1 are energized with a phase difference of 120 °. The same applies to U2, V2, and W2.

  FIG. 2 is a cross-sectional view showing the coil phase sequence at the time of low pole in the method of driving the pole-switching induction machine according to Embodiment 1 of the present invention, and the phase arrangement of the stator windings that realizes low pole driving Is shown.

  In the stator 4 shown in FIG. 2, the case where the stator teeth 5 and the stator slots 6 are arranged at equal intervals with respect to each of the 12 mechanical angles is illustrated. In FIG. 2, the slot arrangement is schematically shown side by side, but in actuality, the outer shape of the stator 4 is circular. A stator coil 7 is inserted into each of the stator slots 6 of slot numbers # 1 to # 12 and is arranged in the phase order described in the stator slot 6 of FIG. Here, what is underlined in order of each phase means that the winding direction of the coil is reversed with respect to those not underlined.

  FIG. 3 is a cross-sectional view showing the coil phase sequence at the time of high poles in the driving method of the pole number switching type induction machine according to Embodiment 1 of the present invention, and the phase arrangement of the stator windings that realizes high pole driving Is shown.

  In FIG. 3, the phase order of the stator coil 7 inserted in the stator 4 is not changed as compared with FIG. 2, and the phase order in the slot numbers # 4 to # 9 in the stator slot 6 is not changed. The energization direction of the coil is reversed. According to the schematic diagram shown in FIG. 1 and the winding arrangement shown in FIGS. 2 and 3, the windings arranged in slot numbers # 1 to # 3 and # 10 to # 12 are wired to the inverter 2 and The windings arranged in the numbers # 4 to # 9 are wired to the inverter 3, and the inverters 2 and 3 wired for each pole pair are switched.

Operation.
Next, operation | movement of the induction machine 1 in this Embodiment 1 is demonstrated. In FIG. 1, the induction machine 1 is connected to and driven by two different three-phase inverters 2 and 3. The two three-phase inverters 2 and 3 are controlled by a general control unit (not shown).

  Here, the phase difference between the phase U1 output from the inverter 2 and the phase U2 output from the inverter 3 is referred to as an intergroup phase difference. The phase difference between groups is arbitrarily controlled from 0 ° to 180 °. At this time, when the inter-group phase difference is set to 0 °, U1 and U2 have the same phase, and the winding arrangement shown in FIG. 2 is obtained. On the other hand, when the inter-group phase difference is set to 180 °, this is equivalent to a state in which the winding directions are opposite in U1 and U2, and the winding arrangement shown in FIG. 3 is obtained.

  That is, the slot phase order shown in FIG. 2 and FIG. 3 is obtained by controlling the winding arrangement of the two three-phase inverters 2 and 3 and the induction machine 1 shown in FIG. It can be seen that this is feasible.

  FIG. 4 is a schematic diagram showing a magnetomotive force waveform at the time of a high pole in the method for driving a pole-switching induction machine according to Embodiment 1 of the present invention, and the magnetomotive force when driven in the phase sequence of FIG. The waveform is shown.

  The horizontal axis in FIG. 4 indicates the slot number of the stator slot 6 shown in the upper part of FIG. The vertical axis in FIG. 4 indicates the magnetomotive force normalized so that the maximum value is 1 at the position corresponding to each slot number of the stator slot 6. The state of FIG. 4 is a state in which current of only I flows in the U phase, −I / 2 in the V phase, and −I / 2 in the W phase. At this time, the number of coil turns in each slot is Are equal.

  When the spatial order for one slot period is k, the magnetomotive force waveform when the inter-group phase difference between the inverters 2 and 3 is 180 ° is as shown in FIG. 4 and the magnetomotive force mainly includes a spatial order of 2k. It turns out that it is a waveform.

  FIG. 5 is a schematic diagram showing a magnetomotive force waveform at the time of a low pole in the method for driving the pole number switching type induction machine according to the first embodiment of the present invention. More specifically, FIG. 5 shows a magnetomotive force waveform when driven in the phase order of FIG. 2, that is, when the inter-group phase difference between the inverters 2 and 3 is 0 ° in the state of FIG. ing.

  The relationship between the horizontal axis and the vertical axis in FIG. 5 is the same as that shown in FIG. According to FIG. 5, it can be seen that there is a magnetomotive force waveform component of spatial order k. In this way, by switching the phase difference between the groups between the inverters 2 and 3 and changing the component of the magnetomotive force waveform, motor drive by switching the number of poles between the high pole and the low pole can be realized.

effect.
Next, effects in the first embodiment will be described. The number of phases of the induction machine 1 in the first embodiment is three. Further, the winding arrangement at the time of high pole shown in FIG. 3 is a winding structure equivalent to a normal distributed winding. Accordingly, when the number of slots per phase per pole at the time of high pole is q, the distributed winding coefficient k _wd is expressed by the following equation (1).
k _wd = sin (π / 6) / (q × sin (π / 6q)) (1)

Here, it can be seen that when q = 1, k _wd = 1, and the distributed winding coefficient is 1 at the maximum. Therefore, by adopting the winding structure in the first embodiment, the effect of realizing high torque with a small current at the time of high pole can be obtained.

  In the winding structure of the conventional induction machine, there exist some which have a distributed winding coefficient of less than 1, such as a short-ply two-layer lap winding. However, unlike the first embodiment, there is no one having a distributed winding coefficient of 1, and it can be seen that the effect of further increasing the torque becomes significant according to the present invention.

  In a vehicle such as a hybrid vehicle that propels the vehicle by supplementing the driving force of the engine with a motor, if the driving force of the vehicle is constant, the amount of assist by the motor is smaller and the engine driving force is smaller. As a result, fuel efficiency can be improved. For example, when accelerating with a constant driving force from a stopped state or a low-speed driving state, driving the motor to assist the engine and supplementing the vehicle's driving force may result in improved fuel efficiency. It is done.

  Therefore, in a motor that enables high-torque operation during high-pole operation by pole number switching described in the first embodiment, the motor assists the engine during low-speed traveling with a low engine speed. In this case, the effect of improving the fuel efficiency as described above can be obtained. Further, since the phase difference between the groups between the inverters 2 and 3 can be arbitrarily controlled, the torque fluctuation at the time of switching the number of poles is suppressed by continuously changing the phase difference from 0 ° to 180 °. An effect is also obtained.

  As described above, according to the first embodiment, the winding structure is such that the winding coefficient at the time of high pole is the above-mentioned formula (1), and the phase difference between the groups between the two inverters is changed. The number of poles is switched. As a result, the number of poles can be switched with a winding structure having a higher winding coefficient, and high torque performance, which has been impossible in the past, can be realized with less current. In addition, torque shock can be suppressed by continuously changing the phase difference when switching the number of poles.

  In the first embodiment, the number of stator winding outlets is six. However, the present invention is not limited to this, and any structure may be used as long as the coils corresponding to each phase of each group can be energized from inverters 2 and 3. . Accordingly, for example, the number of the stator winding outlets may be twelve, and two connection wires may be provided for each phase of each group to energize.

  In the first embodiment, the number of stator slots is set to 12 and the number of slots per phase per pole at the time of high pole is 1 in order to realize switching of the number of poles between 2 poles and 4 poles. The number of poles, the number of stator slots, and the number of slots per pole per phase are not limited, and any distributed winding coefficient at the time of high pole may be expressed by the above equation (1). That is, for example, the number of stator slots is 72, the number of slots per phase per pole at the time of high pole is 2, and the wiring destination inverters 2 and 3 are switched and connected for each pole pair, and 6 poles and 12 poles are connected. It is also possible to use a method that realizes switching of the number of poles.

  In the first embodiment, as shown in FIG. 2 and FIG. 3, one type of coil inserted into one slot has been described. However, a coil inserted into one slot is not necessarily one. It is not limited to types. The spatial order of the magnetomotive force waveform when the phase difference between the groups of the inverters 2 and 3 is 180 ° is double the spatial order of the magnetomotive force waveform when the phase difference between the groups of the inverters 2 and 3 is 0 °. Any coil arrangement may be used. Therefore, two types of coils may exist in one slot.

Embodiment 2. FIG.
In the second embodiment, a method of switching the number of poles according to the number of rotations of the induction machine 1 so as to be 8 poles at the high pole and 4 poles at the low pole will be described. Thereby, the improvement of the maximum torque of a rotation area and the output ensuring in a high rotation area can be made compatible.

Constitution.
FIG. 6 is an example of a cross-sectional view of the induction machine 1 that realizes switching of the number of poles of 4 poles and 8 poles in the driving method of the pole number switching type induction machine according to the second embodiment of the present invention.

  The induction machine 1 according to the second embodiment shown in FIG. 6 includes a stator 4 and a rotor 8. The stator 4 has a cylindrical shape. Forty-eight stator slots 6 are formed by forming 48 stator teeth 5 on the inner peripheral side of the stator 4 so as to be equiangular and intermittent. Has been. In the stator slot 6, the stator coil 7 is wound and stored so as to include a predetermined number of stator teeth 5 therein.

  The rotor 8 includes a rotor core 9, a rotor slot 10, a secondary conductor 11, and a shaft hole 13. The rotor 8 is formed, for example, by laminating and integrating a predetermined number of magnetic steel plates, and the outer peripheral surface forms a substantially cylindrical surface by the rotor core 9. The rotor core 9 is formed by arranging the same 32 rotor slots 10 so as to be equiangular and intermittent, and a secondary conductor 11 is accommodated in each rotor slot 10.

  The rotor 8 is a squirrel-cage rotor made of a conductor in which both ends in the axial direction of the secondary conductor 11 are short-circuited by a short-circuit ring (not shown). On the other hand, it arrange | positions so that it can rotate through the rotation space | gap 14. FIG.

  As shown in FIG. 1, the stator coil 7 is wired to the inverters 2 and 3 to the corresponding phases. The slot number of the stator slot 6 overlapping the wavy line portion shown in FIG. 6 is # 1, and # 2, # 3,..., # 48 counterclockwise starting from # 1 of the stator slot 6 and each stator slot A slot number is added to 6.

  Table 1 shows the phase sequence of energizing the stator coil 7 of the induction machine 1 that realizes the switching of the number of poles of 4 poles and 8 poles in the driving method of the pole number switching type induction machine according to the second embodiment of the present invention. It is a table. Table 1 shows phases for energizing the stator coils 7 inserted in the stator slots 6 indicated by the slot numbers # 1 to # 48. Assuming that driving is performed with 8 poles at the time of high pole, the number of slots per phase per pole is 2, and it is confirmed that the order of the phases to be energized is changed every 2 slots.

Operation.
Next, the operation of the induction machine 1 according to the second embodiment will be described. The stator coils 7 shown in Table 1 are connected in phase order to the inverters 2 and 3 shown in FIG. Alternatively, the angle is switched to 180 °. By driving in this way, the magnetomotive force waveform can be changed as described in the first embodiment. As a result, it is possible to switch the number of poles so that there are 8 poles at the high pole and 4 poles at the low pole.

effect.
FIG. 7 is a first diagram showing torque characteristics at the time of four poles and eight poles in the method of driving a pole number switching type induction machine according to the second embodiment of the present invention. In FIG. 7, the rotational speed is plotted on the horizontal axis, and the torque is plotted on the vertical axis, with values normalized by the maximum rotational speed and maximum torque, respectively. A solid line shows torque characteristics when driven with four poles, and a broken line shows torque characteristics when driven with eight poles.

  According to FIG. 7, in the low rotation range, the 8-pole can generate higher torque than the 4-pole, whereas in the high rotation range, the 4-pole can generate higher torque than the 8-pole. . Therefore, it can be seen that high output can be achieved by switching the number of poles according to the number of rotations.

  FIG. 8 is a second diagram showing torque characteristics at the time of 4 poles and 8 poles in the driving method of the pole number switching type induction machine according to the second embodiment of the present invention. In FIG. 8, the torque near the maximum rotational speed in FIG. 7 is shown by a bar graph. The left side in the bar graph shown in FIG. 8 is the low pole condition and the right side is the high pole condition.

  As shown in FIG. 8, the torque at the time of low poles is about 30% higher than that at high poles in the high speed range, and the output can be increased in the high speed range by switching the number of poles. It can be said that there is.

  Accordingly, in the second embodiment, for example, in a vehicle such as a hybrid vehicle in which the vehicle is propelled by supplementing the driving force of the engine with a motor, the regenerative amount is increased more than before and the charge amount to the in-vehicle battery is increased. Can be increased.

  Specifically, for example, consider a case where the vehicle decelerates from a state where the engine speed is high. When regenerating kinetic energy with a motor / generator, regeneratively with 4 poles with the inter-group phase difference of 0 °. Regeneration is performed at 8 poles with an interphase difference of 180 °.

  In this way, by regenerating while switching the number of poles, the characteristics at the high speed in the 4-pole state and the characteristics at the low speed in the 8-pole state are larger. You can take a lot.

  In addition, the operating range in which the motor efficiency is maximum differs between the time of 8 poles and the time of 4 poles. The loss generated in the motor in the second embodiment includes a large amount of iron loss. For this reason, the rotational speed at which the maximum efficiency is achieved by the 4-pole drive is higher than the rotational speed at which the maximum efficiency is achieved by the 8-pole drive.

  Therefore, as shown in FIG. 7, when the induction machine 1 having a torque characteristic in which there is a region that can be driven at any time of 8 poles or 4 poles is driven in the above region, Compare the efficiency at the time of extreme, and drive in the pole number condition that becomes higher efficiency. As a result, a large amount of regeneration can be obtained, and as a result, an effect of improving fuel consumption can be obtained.

  As described above, according to the second embodiment, the maximum torque can be improved in the low rotation range by appropriately switching the number of poles in a region where either 8-pole or 4-pole can be driven according to the rotation speed of the induction machine. And ensuring output in the high rotation range.

  In the second embodiment, the number of stator slots is 48 in order to realize switching between the number of poles of 4 poles and 8 poles. However, the number of stator slots is not necessarily limited to this, and the number of poles is not limited to 4 poles and 8 poles. Any number of stator slots that can realize switching of the number of poles may be used. That is, for example, a method may be used in which the number of stator slots is 72, and the number of slots per phase per pole at the time of high pole is 3.

Embodiment 3 FIG.
In the third embodiment, a pole-switching induction machine that can suppress an electromagnetic excitation force that is generated when magnetic fluxes generated by the stator 4 and the rotor 8 cross each other will be described. As a result, it is possible to realize pole number switching that achieves both high torque and low noise.

Constitution.
In the pole number switching type induction machine according to the third embodiment, as shown in FIG. 1 of the first embodiment, the stator windings are wired to different groups of three-phase inverters 2 and 3 for each pole pair. In addition, as shown in FIG. 6 of the second embodiment, the number of poles can be switched between 4 poles and 8 poles with 48 stator slots and 32 rotor slots. Yes.

  In addition, the number of poles p, the number of stator slots Ns, and the number of rotor slots Nr of the induction machine 1 are configured to satisfy the following expression (3).

Operation.
With such a configuration, as described in the first embodiment, the group-phase difference between the inverters 2 and 3 is switched to 0 ° or 180 °, thereby switching the number of poles between 4 and 8 poles. Is realized.

effect.
Here, when driving the induction machine 1 according to the third embodiment, the force generated when the magnetic flux generated by the stator 4 and the rotor 8 crosses in the rotation gap 14 ( Hereinafter, the distribution of “electromagnetic excitation force” will be considered.

The radial component of the electromagnetic excitation force when the rotating gap 14 makes one round in the circumferential direction is developed for each spatial order and time order. In general, the induction machine 1 specifies the spatial order and the time order of the characteristic electromagnetic excitation force generated by selecting the number of poles, the number of stator slots, and the number of rotor slots. That is, when the number of poles is p, the number of stator slots is Ns, and the number of rotor slots is Nr, the characteristic spatial order β is described by the following equation.
β = | As · Ns + Ar · Nr + k · p | (k = -1, 0, 1) (2)

  Here, As and Ar are arbitrary integers. In general, in order to suppress noise and vibration due to the electromagnetic excitation force of the induction machine 1, it is effective to reduce the excitation force component having a spatial order of 1 to 3. That is, it is necessary to select the values of Ns and Nr so that the spatial order β does not become a value of 1 to 3 no matter how As and Ar are selected.

Suppose that p is the number of poles during low-pole driving, and j is an integer of 2 or more, and the following relational expression holds.
Nr = Ns ± j · p (3)

At this time,
β = | As · Ns + Ar · (Ns ± jp) + k · p |
= | (As + Ar) · Ns + (± j · Ar + k) p | (4)
It becomes.

Furthermore, when the number of slots per phase per pole is q,
Ns = 3pq (5)
At this time, Ns is a multiple of p.

Therefore, from the above equation (4),
β = | (As + Ar) · 3pq + (± j · Ar + k) p |
= | {(As + Ar) · 3q + (± j · Ar + k)} p |
= | B | ・ p (6)
Here, B = (As + Ar) · 3q + (± j · Ar + k).

  From the above equation (6), it can be seen that β is a multiple of p. Moreover, since all the terms which comprise B are integers, it can be said that B is an integer.

  At this time, it is sufficient that p is 4 or more so that β does not become a value of 1 to 3. Because B is an integer and | B | = 0, 1, 2,..., If p is 4 or more, the smallest value next to 0 out of β is 4. is there. Therefore, if the number of poles p at the time of the low pole is 4 or more and the relational expression (3) is satisfied, β cannot take a value of 1 to 3.

  Therefore, if p is 4 or more, components of spatial orders 1 to 3 due to the electromagnetic excitation force of the induction machine 1 can be suppressed, and as a result, a low noise and low vibration induction machine 1 can be obtained. It becomes. In the third embodiment, p = 4, Ns = 48, and Nr = 32 in the case of the low pole, and the value of Nr at this time certainly conforms to the above equation (3). The

  For example, in a vehicle such as a hybrid vehicle in which the vehicle is propelled by supplementing the driving force of the engine with a motor, the quietness of the induction machine 1 is such that the quietness is required to ensure passenger comfort. It has become one. For this reason, there is a demand for a motor for automobiles that uses a wide range of rotational speeds and is low in noise at any rotational speed.

  In the third embodiment, the spatial order and time order of the electromagnetic excitation force generated by the combination of the number of poles, the number of stator slots, and the number of rotor slots are grasped, and if the relationship of the above equation (3) is satisfied, The electromagnetic excitation force component having a spatial order of 1 to 3 can be reduced. Therefore, when applied to a motor for an automobile, the effect of achieving both low noise and high torque by switching the number of poles can be obtained.

  As described above, according to the third embodiment, the induction machine is configured such that the number of poles p, the number of stator slots Ns, and the number of rotor slots Nr satisfy the above equation (3) (where p ≧ 4). By doing so, it is possible to reduce the noise by suppressing the electromagnetic excitation force generated from the induction machine.

  In the third embodiment, the mode in which the number of poles p at the time of low pole is 4, the number of stator slots is 48, and the number of rotor slots is 32 has been described. However, it is not necessarily limited to this value, the number of poles at the time of low pole is 4 or more, the number of slots q per phase per pole is a natural number, and satisfies the relational expression shown in the above formula (3). A combination is sufficient. Therefore, for example, the same effect can be obtained even in a mode in which the number of poles p at the time of low pole is 6, the number of stator slots is 72, and the number of rotor slots is 60.

  1 Inductor, 2, 3 Inverter, 4 Stator, 5 Stator Teeth, 6 Stator Slot, 7 Stator Coil, 8 Rotor, 9 Rotor Core, 10 Rotor Slot, 11 Secondary Conductor, 13 Shaft Hole , 14 rotation gap.

Claims (7)

Stator coils wound in distributed winding for three-phase driving are alternately connected to two three-phase inverters every other pole pair, and q is the number of slots per pole per phase at high poles. The distributed winding coefficient k _wd is
k _wd = sin (π / 6) / (q × sin (π / 6q)), and the pole number switching type induction machine having a general control unit that drives and controls the two three-phase inverters, A method of driving a pole-switching induction machine executed by a general control unit,
In the overall control unit, the number of poles is switched so that the inter-group phase difference between the two three-phase inverters is in the range of 0 ° to 180 °, with a low pole at 0 ° and a high pole at 180 °. A method of driving a pole-switching induction machine having steps. The method of driving a pole number switching type induction machine according to claim 1, wherein the step of switching the number of poles switches the number of poles of the phase difference between groups to either the low pole or the high pole. The pole number switching type induction machine according to claim 2, wherein the step of switching the number of poles switches the number of poles so that the inter-group phase difference is 4 poles at the low pole and 8 poles at the high pole. Method. The step of switching the number of poles switches the number of poles so that a higher torque performance can be obtained with a smaller current according to the number of rotations of the pole number switching type induction machine. 4. The method for driving a pole-switching induction machine according to any one of 3 above. The method of driving a pole number switching type induction machine according to any one of claims 1 to 4, wherein the step of switching the number of poles switches the number of poles by continuously changing the phase difference between the groups. Stator coils wound in distributed winding for three-phase driving are alternately connected to two three-phase inverters every other pole pair, and an overall control unit for driving and controlling the two three-phase inverters It is a pole number switching type induction machine provided,
The overall control unit switches the number of poles so that the phase difference between groups of the two inverters is in a range of 0 ° to 180 °, and a low pole at 0 ° and a high pole at 180 °,
The distributed winding has a distributed winding coefficient k _wd where q is the number of slots per phase per pole when the inter-group phase difference is the high pole.
k _wd = sin (π / 6) / (q × sin (π / 6q))
A pole-switching induction machine configured to be When the number of stator slots is Ns, the number of poles at the time of the low pole is p, p is an integer of 4 or more, and j is an integer of 2 or more, the number of rotor slots Nr is
Nr = (Ns + j · p) or (Ns−j · p)
The pole number switching type induction machine according to claim 6.

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