Rotating electric machine

One end of each of phase conductors wound around a stator core in a wave winding arrangement is connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch and is connected to a negative electrode terminal of the DC power supply through a second negative electrode side switch. The other end of the phase conductor is connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch and is connected to the positive electrode terminal of the DC power supply through a second positive electrode side switch. The first positive electrode side switch, the second negative electrode side switch, the first negative electrode side switch, and the second positive electrode side switch are controlled by a controller, whereby amplitude and phase of current passing through each of the phase conductors are individually controlled.

TECHNICAL FIELD

The present invention relates to a rotating electric machine capable of switching the amplitude and phase of current passing through armature conductors depending on the operating state thereof.

BACKGROUND ART

There has been a proposed rotating electric machine that has an increased operating range and an improved characteristic by switching the number of turns of armature winding or a connection method between windings in the rotating electric machine.

For example, PTL 1 discloses an induction motor that has an increased operating range and an improved characteristic by switching the connection of coils having the same phase in armature winding constituted by n partial windings between series connection and parallel connection, and the phase coil connection between Y connection and Δ connection.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

Here, between a high speed range and a low speed range and between a high load range and a low load range in an operating range, different characteristics are required of a rotating electric machine.

For example in a low load range, torque ripple or current ripple is relatively large for output torque or input/output current, the effect of which is significant, and therefore a characteristic with small ripple is necessary.

Meanwhile, what is most required in a high load range is to keep the temperature of components that constitute the rotating electric machine within an acceptable value range.

In the induction motor described above, the line voltage peak value and the current density of the phase coil are changed for example by changing the number of turns of the phase coil, serial-parallel switching, or Y-Δ connection change, but the gap magnetic flux density waveform itself between the stator and the rotor does not change by these kinds of switching, and characteristics attributable to the gap magnetic flux waveform such as torque ripple and current ripple cannot be changed.

Generally, a gap magnetic flux distribution generated by an armature by distributed winding can approximate to a sinusoidal wave more than concentrated winding, and a gap magnetic flux distribution by short-pitch winding can approximate to a sinusoidal wave more than full-pitch winding.

Therefore, torque ripple may be reduced in a rotating electric machine having a short-pitch winding pattern more easily than in a machine having a concentrated winding pattern.

Meanwhile, since a magnetic flux use efficiency by short-pitch winding is low, more current is necessary to provide necessary torque, and therefore it is difficult to establish a target temperature with a high load.

A rotating electric machine free from the problem can be provided if different magnetic flux waveforms may be reproduced by changing the amplitude and phase of current passed through phase coils using a distributed winding or a concentrated winding either in a full-pitch winding or short-pitch winding arrangement.

However, in practice, current must be passed in such a manner that magnetic fluxes generated by phase coils cancel each other as the magnetic fluxes are combined, which in turn results in a useless conductor that only generates a conductor loss without contributing to torque generation, and the efficiency is lowered.

Now, the useless conductor will briefly be described.

FIG. 17is a view of a coil50wound around a stator core51when viewed in the axial direction of a rotating electric machine,FIG. 18is a diagram showing the direction of current passing through the coils50when viewed in the radial direction of the rotating electric machine inFIG. 17, and the arrow indicates the direction of the current passing through the coil50.

In a conventional arrangement for switching among full-pitch winding, short-pitch winding, and concentrated winding, for example the concentrated winding coil50is wound around the stator core51.

When a magnetic flux waveform is generated by a distributed winding at intervals of two slots as shown inFIG. 17, the adjacent intermediate coils50are connected with each other so that the coils50at intervals of two slots are connected.

In this case, as can be understood fromFIG. 18, the directions of current passing through the two coils50inserted in the same slot are opposite to each other, and therefore the magnetic fluxes cancel each other.

Therefore, the intermediate coils50between the connected coils50at intervals of two slots end up being a so-called useless conductor that generates a conductor loss by current passed therethrough but does not generate any effective magnetic flux.

Furthermore, when a large number of partial windings are connected through switches such as transistors and the states of the windings are changed in response to the opening/closing of the switches as disclosed in PTL 1, the number of switches and switch controllers would be enormous, which complicates the machine and increases the size of the machine.

It is an object of the present invention to solve the problem and provide a low-loss rotating electric machine that is free from a loss attributable to a useless conductor and forms a gap magnetic flux waveform for providing an increased operating range and an optimum characteristic required in each operating point without increasing the number of switches and switch controllers.

Solution to Problem

A rotating electric machine according to the present invention includes a rotor, and a stator provided to surround the rotor and including a stator core in which a plurality of axially extending stator slots are formed and phase conductors inserted through the stator slots each in a wave winding arrangement, the phase conductors each have one end electrically connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch that turns on and off current and electrically connected to a negative electrode terminal of the DC power supply through a negative electrode side part that controls current, the phase conductors each have the other end electrically connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch that turns on and off current and electrically connected to the positive electrode terminal of the DC power supply through a positive electrode side control part that controls current, and the first positive electrode side switch, the negative electrode side control part, the first negative electrode side switch, and the positive electrode side control part are controlled by a controller, so that an amplitude and a phase of current passing through each of the phase conductors are individually controlled.

Advantageous Effects of Invention

In the rotating electric machine according to the present invention, the phase conductors inserted through the stator slots in a winding wave arrangement each have one end electrically connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch that turns on and off current and electrically connected to a negative electrode terminal of the DC power supply through a negative electrode side control part that controls current and the phase conductors each have the other end electrically connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch that turns on and off current and electrically connected to the positive electrode terminal of the DC power supply through a positive electrode side control part that controls current, and the first positive electrode side switch, the negative electrode side control part, the first negative electrode side switch, and the positive electrode side control part are controlled by a controller, so that an amplitude and a phase of current passing through each of the phase conductors are individually controlled.

Therefore, a low-loss rotating electric machine that is free from a loss attributable to a useless conductor can be provided, and the machine forms a gap magnetic flux waveform for providing an increased operating range and an optimum characteristic required in each operation point without increasing the number of switches and switch controllers.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described in conjunction with the accompanying drawings, in which the same or corresponding members and portions will be designated by the same reference characters.

First Embodiment

FIG. 1is a side sectional view of a motor1according to a first embodiment of the invention, andFIG. 2is a front sectional view of the motor1inFIG. 1.

The motor1is a permanent magnet motor having eight poles and 48 slots.

The motor1as a rotating electric machine includes a cylindrical frame2, a load side bracket3and a counter load side bracket4provided to cover both sides of the frame2, a shaft7provided on the central axial line of the frame2and rotatably supported at two points, i.e., at the load side bracket3and the counter load side bracket4through a load side bearing5and a counter load side bearing6, a rotor8that has the shaft7inserted therein for integration for example by a key and is stored in a case10constituted by the frame2, the load side bracket3and the counter load side bracket4, and an annular stator9fixed at the inner wall surface of the frame2for example by press-fitting or shrinkage fitting to surround the rotor8with a gap therebetween.

The load side bearing5is axially fixed to the load side bracket3by a bearing presser11using a bolt or the like. The counter load side bearing6is provided with a degree of freedom in the axial direction with respect to the counter load side bracket4through a wave washer12.

The case10is formed by fixing the load side bracket3and the counter load side bracket4to the frame2by bolts or the like.

The stator9includes a stator core15having 48 teeth14that project at equal intervals radially inwardly from the inner circumferential side of an annular yoke13, two phase conductors17having the same phase and inserted side by side in the radial direction through each of the stator slots16that are formed between the teeth14and extend axially, and an insulator18that covers the phase conductors17.

The stator core15is formed by laminating, on one another, a plurality of thin steel plates having both surfaces insulation treated.

The phase conductors17are integrally molded with the insulator18, and the phase conductors17coated with the insulator18are pressed into the stator slots16and fixed to the stator core15as a result.

The phase conductors17are each inserted through a stator slot16from one end of the stator core15in the axial direction and exposed on the other end thereof, then inserted through the stator slot16separated by one pole pitch, i.e., the sixth stator slot16in the circumferential direction, from the other end of the stator slot16in the axial direction of the stator core15, and exposed on the one end thereof, and again inserted through the stator slot16separated by one pole pitch in the circumferential direction from the one end of the stator slot16, and exposed on the other end thereof.

The phase conductors17are inserted through the stator slots16in this manner three times in total around the stator core15in the wave winding arrangement.

Note that inFIG. 2, two phase conductors17having the same phase are inserted in each stator slot16, and 12 phase conductors17in total are wound around the stator core15in the wave winding arrangement.

The section inFIG. 2shows only one position collectively while a section of three positions of the phase conductors17including the inner diameter side phase conductor17and the outer diameter side phase conductor17should be indicated to represent the actual arrangement.

The ends of each of the phase conductors17are connected with one end of a load side lead23and one end of a counter load side lead24. The load side lead23and the counter load side lead24are drawn out from the motor1through an outlet25formed at the frame2.

The rotor8includes a cylindrical rotor core19having eight magnet slots20in total that are formed at equal intervals in the circumferential direction and extend in the axial direction, permanent magnets21inserted in the magnet slots20so that the N poles and the S poles are alternately positioned on the outer diameter side, and end plates22fixed at the axial ends of the rotor core19to block the sides of the magnet slot20.

The end plates22are desirably made of a non-magnetic material.

FIG. 3is a feeding circuit diagram showing a feeding circuit for the motor1inFIG. 1.

The load side lead23is electrically connected to the positive electrode terminal31of a DC power supply27through a first positive electrode side switch26that turns on and off current and also electrically connected to the negative electrode terminal32of the DC power supply27through a second negative electrode side switch28serving as a negative electrode side control part that controls turning on and off of current.

The counter load side lead24is electrically connected to the negative electrode terminal32of the DC power supply27through a first negative electrode side switch29that turns on and off current and also electrically connected to the positive electrode terminal31of the DC power supply27through a second positive electrode side switch30serving as a positive electrode side control part that controls turning on and off of current.

In this manner, the feeding circuit for the motor1constitutes a so-called H-bridge circuit by the first positive electrode side switch26, the second negative electrode side switch28, the first negative electrode side switch29, and the second positive electrode side switch30.

Note that although not shown inFIG. 3, the amplitude and phase of current to be passed through each of the phase conductors17are individually adjusted by controllers that control driving of the switches26,30,29, and28.

One such controller is provided for each of the switches26,30,29, and28.

The first positive electrode side switch26, the second positive electrode side switch30, the first negative electrode side switch29, and the second negative electrode side switch28are insulated gate bipolar transistors (IGBTs) using silicon semiconductor but these switches may be metal-oxide-semiconductor field-effect transistors (MOS-FETs).

Alternatively, the switches may be semiconductor switches using wide bandgap semiconductor such as silicon carbide (SiC) or gallium nitride (GaN).

Although not shown, flyback diodes are inserted in the first positive electrode side switch26, the second positive electrode side switch30, the first negative electrode side switch29, and the second negative electrode side switch28parallel to these switches.

The DC power supply27may be a lead battery or a lithium ion battery.

The phase conductors17are each electrically connected to an individual H-bridge circuit, and the H-bridge circuits are each provided with an individual DC power supply27.

Therefore, according to the embodiment, 12 H-bridge circuits, 12 phase conductors17, and12controllers altogether are provided for one motor1.

InFIG. 3, when the first positive electrode side switch26and the first negative electrode side switch29are turned on and the second negative electrode side switch28and the second positive electrode side switch30are turned off in response to driving of the controllers, the end of the load side lead23attains a positive electrode side potential, and the end of the counter load side lead24attains a negative electrode side potential.

As a result, current passes through the phase conductor17from the load side lead23to the counter load side lead24.

Meanwhile, when the first positive electrode side switch26and the first negative electrode side switch29are turned off and the second negative electrode side switch28and the second positive electrode side switch30are turned on in response to driving of the controllers, the end of the load side lead23attains a negative electrode side potential, and the end of the counter load side lead24attains a positive electrode side potential.

As a result, current passes through the phase conductor17from the counter load side lead24to the load side lead23.

When the four switches26,30,29, and28of the H-bridge circuit are all turned off, the phase conductor17is disconnected from the DC power supply27and no current is passed therethrough.

In this manner, the controller switches between on and off states of the switches26,30,29, and28and changes the ratio of on and off periods for the switches, so that current having an arbitrary amplitude and phase may be passed through each of the phase conductors17.

Now, the operation of the motor1will be described with reference to a 6-phase motor1having the above configuration.

InFIG. 4, letters a to x are allocated to the phase conductors17in the circumferential direction.

A+, B+, C+, D+, E+, and F+ represent six AC phases having the same amplitude and sequentially shifted by 30°, and A−, B−, C−, D−, E−, and F− represent states in which phases are inverted from A+, B+, C+, D+, E+, and F+, respectively.

When the motor1drives a full-pitch distributed winding, the phases of current to be passed through the phase conductors17are adjusted as follows.

More specifically, the phases of current to be passed through the phase conductors17are adjusted so that the phase A+ is allocated to the phase conductors17marked with a and b, the phase B+ to the phase conductors17marked with c and d, the phase C+ to the phase conductors17marked with e and f, the phase D+ to the phase conductors17marked with g and h, the phase E+ to the phase conductors17marked with i and j, and the phase F+ to the phase conductors17marked with k and l.

In this manner, an armature flux for an 8-pole, 48-slot motor having a 6-phase full pitch distributed winding with one slot per pole per phase as shown inFIG. 5can be provided.

Note that the position shifted by one pole pitch in the rotation direction is in rotation odd symmetry.

More specifically, the phase conductor17marked with a for example extends from the front side of the sheet surface inFIG. 4perpendicularly to the back side, skips over stator slots16for one pole pitch in the circumferential direction, and then extends from the back side of the sheet surface to the front side perpendicularly from the stator slot16marked with m.

When the motor1drives a short-pitch distributed winding, the phases of current to be passed through the phase conductors17are adjusted as follows.

More specifically, the phases of current to be passed through the phase conductors17are adjusted so that the phase A+ is allocated to the phase conductor17marked with a, the phase D− to the phase conductor17marked with b, the phase B+ to the phase conductor17marked with c, the phase E− to the phase conductor17marked with d, the phase C+ to the phase conductor17marked with e, the phase F− to the phase conductor17marked with f, the phase D+ to the phase conductor17marked with g, the phase A− to the phase conductor17marked with h, the phase E+ to the phase conductor17marked with i, the phase B− to the phase conductor17marked with j, the phase F+ to the phase conductor17marked with k, and the phase C− to the phase conductor17marked with l.

In this manner, an armature flux for an 8-pole, 48-slot motor having a 6-phase short-pitch distributed winding with one slot per pole per phase as shown inFIG. 6can be provided.

Note that the position shifted by one pole pitch in the rotation direction is in rotation odd symmetry.

When the motor1drives a concentrated winding, the phases of current to be passed through the phase conductors17are adjusted as follows.

More specifically, the phases of current to be passed through the phase conductors17are adjusted so that the phase A+ is allocated to the phase conductor17marked with a, the phase F+ to the phase conductor17marked with b, the phase B+ to the phase conductor17marked with c, the phase A− to the phase conductor17marked with d, the phase C+ to the phase conductor17marked with e, the phase B− to the phase conductor17marked with f, the phase D+ to the phase conductor17marked with g, the phase C− to the phase conductor17marked with h, the phase E+ to the phase conductor17marked with i, the phase D− to the phase conductor17marked with j, the phase F+ to the phase conductor17marked with k, and the phase E− to the phase conductor17marked with l.

In this manner, an armature flux for an 8-pole, 48-slot motor having a 6-phase concentrated winding with one slot per pole per phase as shown inFIG. 7can be provided.

Note that the position shifted by one pole pitch in the rotation direction is in rotation odd symmetry.

The phase conductors17are conducted in this manner, so that the motor1can drive the 6-phase full-pitch winding, the 6-phase short-pitch winding, and the 6-phase concentrated winding.

Unlike conventional motors, the 6-phase motor1with any of the above configurations does not need such current feeding that magnetic fluxes generated by the phase coils cancel each other as the magnetic fluxes are combined, and since current may be fed to only the necessary phase conductors17, magnetic flux waveforms for the 6-phase full-pitch winding, the 6-phase short-pitch winding, and the 6-phase concentrated winding can be provided without creating a useless conductor.

The phase conductors17wound around the stator core15in the wave winding arrangement shifted per pole pitch in the circumferential direction are connected to the H-bridge circuit constituted by the switches26,28,29, and30, and therefore the gap magnetic flux waveform can be arbitrarily adjusted without increasing the switches26,28,29, and30and the controllers.

Now, the operation of the motor1with the above configuration will be described with reference to a 3-phase motor1.

Similarly to the above, in the 3-phase motor, U+, V+, and W+ represent three AC phases having the same amplitude and sequentially shifted by 120°, and U−, V−, and W− represent states in which the phases are inverted from U+, V+, and W+, respectively.

When the motor1drives a full-pitch winding, the phases of current to be passed through the phase conductors17are adjusted as follows.

More specifically, when the phases of current are adjusted so that the phase U+ is allocated to the phase conductors17marked with a, b, c, and d, the phase W− is allocated to the phase conductors17marked with e, f, g, and h, and the phase V+ is allocated to the phase conductors17marked with i, j, k, and l, current is passed through the armature according to a conduction method for a 3-phase full-pitch distributed winding.

In this manner, an armature flux for an 8-pole, 48-slot motor having a 3-phase full-pitch winding with two slots per pole per phase as shown inFIG. 8can be provided.

When the motor1drives a concentrated winding, the phases of current to be passed through the phase conductors17are adjusted as follows.

More specifically, an armature flux for an 8-pole, 48-slot motor having a 3-phase concentrated winding as shown inFIG. 9can be provided when current is passed so that the phase V− is allocated to the phase conductor17marked with a, the phase U+ to the phase conductor17marked with b, the phase U+ to the phase conductor17marked with e, the phase W− to the phase conductor17marked with f, the phase W− to the phase conductor17marked with i, and the V+ to the phase conductor17marked with j, and no current is passed through the phase conductors17marked with c, d, g, h, k, and l.

Current is passed through the phase conductors17in this manner, so that the motor1can drive the 3-phase full-pitch winding and the 3-phase concentrated winding.

In the 3-phase motor1with the above configuration, the operation of the first positive electrode side switch26, the second negative electrode side switch28, the first negative electrode side switch29, and the second positive electrode side switch30is controlled by the controllers, so that the amplitude and phase of current passing through the phase conductors17are controlled for each of the phase conductors17, a gap magnetic flux density waveform between the stator9and the rotor8can be adjusted in an arbitrary manner, an optimum magnetic flux waveform required for each operation point can be formed, a full-pitch winding, a short-pitch winding, and a concentrated winding can be driven, and the torque pulsation may be reduced depending on the operation state or the use efficiency of the magnetic flux may be improved or changed.

The armature winding is configured so that the amplitude and phase can be changed independently by the four switches26,28,29, and30and the phase conductors17, the phase conductors17inserted through the stator slots16are configured so that the current amplitudes and phases can be independently controlled, and therefore a conductor loss attributable to a useless phase conductor is not generated.

Therefore, the motor1with the above configuration drives in a conduction pattern that simulates a gap magnetic flux waveform by a short-pitch distributed winding in order to reduce torque ripple when driving at low rotation speed with low torque.

The motor drives in a conduction pattern that simulates a gap magnetic flux waveform by a full-pitch distributed winding with a high magnetic flux use ratio when driving with high torque.

During driving at high rotation speed with high torque that cause the permanent magnet21to be demagnetized, a phase conductor17facing the delay side (back side) in the rotation direction of the permanent magnet21with a gap therebetween according to the rotation of the rotor8is driven with smaller conduction current than usual.

Meanwhile, a phase conductor17facing the center part is driven with more conduction current than usual.

In this manner, a magnetic flux generated by a coil that applies a reverse magnetic field on the part of the permanent magnet21most prone to demagnetization can be reduced while maintaining the output torque, so that anti-demagnetization performance can be improved.

Note that controllers for controlling the switches26,30,29, and28by adjusting current to be passed through the phase conductors17are provided for the switches on a one-to-one basis, but since the first positive electrode side switch26and the first negative electrode side switch29are always turned on and off in synchronization with each other and the second negative electrode side switch28and the second positive electrode side switch30are always turned on and off in synchronization with each other, the first positive electrode side switch26and the first negative electrode side switch29may be controlled using the same controller while the second negative electrode side switch28and the second positive electrode side switch30may be controlled using the same controller.

In this manner, the number of controllers may be reduced to half.

In addition, according to the embodiment, the two phase conductors17inserted in the stator slot16are provided side by side in the radial direction but the phase conductors may be arranged in the circumferential direction.

In this way, inductance variations among the phases may be reduced.

Second Embodiment

FIG. 10is a front sectional view of a motor1according to a second embodiment of the present invention.

According to the embodiment, one phase conductor17is inserted in each of the stator slots16.

More specifically, in the 6-phase motor1, the phase conductors17denoted as17a,17b,17c,17d,17e, and17feach extend perpendicularly from the front side of the sheet surface to the back side inFIG. 10, then skip over stator slots16for one pole pitch in the circumferential direction, and then extend from the stator slot16perpendicularly from the back surface of the sheet surface to the front side.

The phase conductors17a,17b,17c,17d,17e, and17fare each individually connected to an H-bridge circuit constituted by the first positive electrode side switch26, the second negative electrode side switch28, the first negative electrode side switch29, and the second positive electrode side switch30.

The rest of the configuration is the same as that of the motor1according to the first embodiment.

In the motor1according to the second embodiment, composite current of current through two phase conductors17inserted in the stator slot16according to the first embodiment is passed through the phase conductors17a,17b,17c,17d,17e, and17f.

In this manner, the number of DC power supplies27, the number of switches26,30,29, and28, and the number of controllers can be reduced to half, so that the machine can be compact.

Only one molded insulator18is provided for each of the phase conductors17a,17b,17c,17d,17e, and17fin the stator slots16, so that the occupancy of the phase conductors17a,17b,17c,17d,17e, and17fin the stator slots16can be increased and high efficiency can be achieved.

Third Embodiment

FIG. 11is a front sectional view of a motor1according to a third embodiment of the present invention, andFIG. 12is a partly enlarged view ofFIG. 11.

The motor1according to the embodiment is a 10-pole, 45-slot permanent magnet motor.

The phase conductors17of the motor1are each inserted through a stator slot16from one end of the stator core15in the axial direction and exposed on the other end thereof, subsequently skip over stator slots16in the circumferential direction, are then inserted through the ninth stator slot16from the other end of the stator slot16in the axial direction of the stator core15and exposed on the one end thereof, subsequently skip over stator slots16in the circumferential direction, and are again inserted through the ninth stator slot16from the one end of the stator slot16in the axial direction of the stator core15and exposed on the other end thereof.

The phase conductors17are inserted through the stator slots16in this manner three times in total around the stator core15in a wave winding arrangement.

Note that one phase conductor17shown inFIGS. 11 and 12includes two phase conductors17having the same phase inserted in each stator slot16, and 18 phase conductors17in total are wound around the stator core15in the wave winding arrangement.

Note that the sectional views inFIGS. 11 and 12show only one position collectively while a section of three positions of the phase conductors17including the inner diameter side phase conductor17and the outer diameter side phase conductor17should be indicated to represent the actual arrangement.

The phase conductors17are each individually electrically connected to an H-bridge circuit constituted by the first positive electrode side switch26, the second negative electrode side switch28, the first negative electrode side switch29, and the second positive electrode side switch30.

The rest of the configuration is the same as that of the motor1according to the first embodiment.

Now, the operation of the motor1with the above configuration will be described with reference to a 9-phase motor1.

InFIG. 12, letters a to r are allocated to the phase conductors17in the circumferential direction.

In the case, the phases of current to be passed through the phase conductors17are adjusted so that the phase A+ is allocated to the phase conductor17marked with a, the phase F− to the phase conductor17marked with b, the phase B+ to the phase conductor17marked with c, the phase G- to the phase conductor17marked with d, the phase C+ to the phase conductor17marked with e, the phase H− to the phase conductor17marked with f, the phase D+ to the phase conductor17marked with g, the phase I− to the phase conductor17marked with h, the phase E+ to the phase conductor17marked with i, the phase A− to the phase conductor17marked with j, the phase F+ to the phase conductor17marked with k, the phase B− to the phase conductor17marked with l, the phase G+ to the phase conductor17marked with m, the phase C− to the phase conductor17marked with n, the phase H+ to the phase conductor17marked with o, the phase D− to the phase conductor17marked with p, the phase I+ to the phase conductor17marked with q, and the phase E− to the phase conductor17marked with r.

In this manner, an armature flux for a 10-pole, 45-slot motor having a 9-phase short-pitch distributed winding with ½ slot per pole per phase as shown inFIG. 13can be provided.

Note that the part of which rotation direction is not shown is in rotation even symmetry.

For example, inFIG. 12, the phase conductor17marked with a extends perpendicularly from the front side of the sheet surface to the back side, then spans stator slots16for two pole pitches in the circumferential direction, and then extends perpendicularly from the back side of the sheet surface to the front side from the adjacent stator slot16on the left of q that is not shown.

The phases of current to be passed through the phase conductors17are adjusted so that the phase I− is allocated to the phase conductor17marked with a, the phase A+ to the phase conductor17marked with b, the phase A− to the phase conductor17marked with c, the phase B+ to the phase conductor17marked with d, the phase B− to the phase conductor17marked with e, the phase C+ to the phase conductor17marked with f, the phase C− to the phase conductor17marked with g, the phase D+ to the phase conductor17marked with h, the phase D− to the phase conductor17marked with i, the phase E+ to the phase conductor17marked with j, the phase E− to the phase conductor17marked with k, the phase F+ to the phase conductor17marked with l, the phase F− to the phase conductor17marked with m, the phase G+ to the phase conductor17marked with n, the phase G− to the phase conductor17marked with o, the phase H+ to the phase conductor17marked with p, the phase H− to the phase conductor17marked with q, and the phase I+ to the phase conductor17marked with r.

In this manner, an armature flux for a 10-pole, 45-slot motor with a 9-phase concentrated winding as shown inFIG. 14can be provided.

Also in this case, the part of which rotation direction is not shown is in rotation even symmetry.

Now, the operation of the motor1with the above configuration will be described with reference to a 3-phase motor1.

Similarly, in the 3-phase motor1, phases U+, V+, and W+ are three AC phases having the same amplitude and sequentially shifted by 120°, and phases U−, V−, and W− represent states in which the phases are reversed with respect to the phases U+, V+, and W+, respectively.

In this case, the phases of current to be passed through the phase conductors17are adjusted so that the phase U+ is allocated to the phase conductors17marked with a, b, and c, the phase W− to the phase conductors17marked with d, e, and f, the phase V+ to the phase conductors17marked with g, h, and i, the phase U− to the phase conductors17marked with j, k, and l, the phase W+ to the phase conductors17marked with m, n, and o, and the phase V− to the phase conductors17marked with p, q, and r.

In this manner, a magnetic flux for a 10-pole, 45 slot motor having a 3-phase short-pitch distributed winding as shown inFIG. 15can be provided.

Similarly, the phases of current to be passed through the phase conductors17are adjusted so that the phase V+ is allocated to the phase conductor17marked with a, the phase U+ to the phase conductor17marked with b, the phase U− to the phase conductor17marked with c, the phase U+ to the phase conductor17marked with d, the phase U− to the phase conductor17with e, the phase W− to the phase conductor17with f, the phase W+ to the phase conductor17marked with g, the phase V+ to the phase conductor17with h, the phase V− to the phase conductor17marked with i, the phase V+ to the phase conductor17marked with j, the phase V− to the phase conductor17marked with k, the phase U− to the phase conductor17marked with l, the phase U+ to the phase conductor17marked with m, the phase W+ to the phase conductor17marked with n, the phase W− to the phase conductor17marked with o, the phase W+ to the phase conductor17marked with p, the phase W− to the phase conductor17marked with q, and the phase V− to the phase conductor17marked with r.

In this manner, an armature flux for a 10-pole, 45-slot motor having a 3-phase concentrated winding as shown inFIG. 16can be provided.

Also in this case, current may be passed so that the phase W− is a allocated to the phase conductor17marked with a, the phase U+ to the phase conductor17marked with b, the phase U− to the phase conductor17marked with g, the phase V+ to the phase conductor17marked with h, the phase V− to the phase conductor17marked with m, and the phase W+ to the phase conductor17marked with n while one third of the phase conductors17are inactivated, and an armature flux for a 10-pole, 15-slot motor having a 3-phase concentrated winding can be provided while assuming that the inactive stator slots as dummy slots.

This configuration still provides the same advantageous effects as those of the first embodiment.

In the motor1according to the third embodiment, two phase conductors17are inserted through each of the stator slots16, while one phase conductor for each of the stator slot16, i.e., nine phase conductors in total may be inserted, current having an amplitude and a phase resulting from the vector sum of current passed through the two phase conductors may be passed through the phase conductors, and still the same advantageous effects may be provided.

Note that in the description of the embodiments, the second negative electrode side switch28is used as a negative electrode side control part and the second positive electrode side switch30is used as a positive electrode side control part, but naturally the arrangement is not limited to the above.

For example, diodes may be used in place of the second negative electrode side switch28serving as the negative electrode side control part and the second positive electrode side switch30serving as the positive electrode side control part both for controlling current, and these diodes may constitute an H-bridge circuit together with the first positive electrode side switch26and the first negative electrode side switch29.

In the above description, the motor1is a permanent magnet motor having the permanent magnets21at the rotor8, but the rotor8may be a switched reluctance motor constituted by a rotor core having projecting poles, a wound field motor provided with a winding around the projecting poles of a rotor core to form magnetic poles, an induction motor having phase conductors inserted in a plurality of grooves at a rotor core and short-circuited by a ring-shaped conductor between the axial ends thereof, or a synchronous reluctance motor provided with a plurality of gaps on the inner side of a substantially circular rotor core, and still the same advantageous effects may be provided.

Alternatively, a linear motor having a configuration in which a rotor is unrolled on a flat surface may be used for the motor1according to any of the embodiments, and still the same advantageous effects can be provided.

The invention is also applicable to a generator as a rotating electric machine.

REFERENCE SIGNS LIST