JP2010154717A - Motor drive apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive apparatus, having an inexpensive, compact and new configuration with a few power wirings between a motor and a three-phase inverter which is an inexpensive configuration that uses a general three-phase inverter module. <P>SOLUTION: The motor drive apparatus includes a three-phase inverter 11 having a full-bridge configuration in which the output side of two FETs is connected in series, with a bridge side of each phase which is connected between a positive terminal and a negative terminal of a battery 17 and a diode is connected among output terminals of both the FETs; and a control unit 11 for turning on and off the FETs of the three-phase inverter 11. A coil 4 for each phase of the motor 1 is provided between each of the connection points of the bridge side of each phase and both FETs and a neutral point of a star-shaped connection, and a combination of applying an electric current to the coil 4 of each phase with an electrical angle of 120° is changed, by turning on and off the FETs via the control unit 11 so that an electric current is applied to two phases with an electric angle of 240° rather than the coils on both ends. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stator in which a plurality of concentrated winding (toroidal winding) coils are wound in the circumferential direction in opposite directions so as to have different excitation directions from adjacent coils, and a circle inside the stator. The present invention relates to a motor driving device that drives a motor including a rotor having a plurality of salient poles formed in a circumferential direction.

  2. Description of the Related Art Conventionally, as a drive motor for an electric vehicle, a motor represented by a switched reluctance motor (hereinafter referred to as an SR motor) in which a three-phase concentrated winding coil is arranged in a phase sequence on a stator is used.

  A double salient pole type SR motor in which salient poles are formed on both the stator and the rotor is formed as shown in FIG. The R motor 100 shown in FIG. 9 includes a stator 200 having a yoke formed of a soft magnetic material (silicon steel plate or the like) and a rotor 300 inside the stator 200. A plurality of radially inward salient poles 201 are formed in the circumferential direction on the inner peripheral surface of the yoke of the stator 200, and a plurality of radially outward salient poles 301 are also circular on the peripheral surface of the yoke of the rotor 300. It is formed in the circumferential direction. Further, concentrated winding three-phase A, B, and C coils 400 are sequentially arranged on each salient pole 201 of the stator 200 (see, for example, Patent Document 1).

  The SR motor 1 having the above configuration is driven by a motor driving device including the three-phase inverter unit 500 having the configuration shown in FIG. In FIG. 10, reference numeral 600 denotes, for example, a vehicle battery, and reference numeral 501 denotes an energy storage capacitor connected in parallel to the battery 600, and forms a DC power source for the three-phase inverter unit 500 together with the battery 600. Reference numerals 502ap and 502an denote FETs (switching elements) on the positive side and the negative side of the A-phase bridge side a in which the output side is connected in series across the A-phase coil 400. 502 bp and 502 bn are positive side and negative side FETs (switching elements) of the B-phase bridge side b in which the output side is connected in series with the B-phase coil 400 sandwiched between the positive and negative ends of the DC power supply. Reference numerals 502 cp and 502 cn denote FETs (switching elements) on the positive and negative sides of the C-phase bridge side c in which the output side is connected in series with the C-phase coil 400 interposed between the positive and negative ends of the DC power supply. 503ap, 503bp, and 503cp are feedback diodes whose anodes are connected to the connection points between the FETs 502an, 502bn, and 502cn of each phase and the coil 400, and the cathodes are connected to the positive side (+) of the DC power supply. Reference numerals 503an, 503bn, and 503cn are feedback diodes whose cathodes are connected to the connection points of the FETs 502ap, 502bp, and 502cp of each phase and the coil 400, and their anodes are connected to the negative side (−) of the DC power supply. In FIG. 10, a plurality of coils 400 connected in series and parallel in each phase are represented by one coil 400, and the connection configuration of the plurality of coils 400 in each phase is omitted.

As described in Patent Document 1, energization excitation of the A-phase coil 400 by turning on the FETs 502ap and 502an, energization excitation of the B-phase coil 400 by turning on the FETs 502bp and 502bn, and turning on the FETs 502cp and 502cn. The energization excitation of the C-phase coil 400 is performed by switching in phase order. As a result, the rotor 300 of the SR motor 100 is magnetically attracted and rotates in the direction of the arrow line in FIG.
JP 11-2113229 A

  Conventionally, this type of motor represented by the SR motor 1 is driven by a motor driving device having the three-phase inverter unit 500 of FIG. 10 in order to energize and energize the concentrated winding coils of each phase of the stator in order. In this case, the three-phase inverter unit 500 is different from the general-purpose three-phase inverter module, which is an intelligent power module (IPM), which has become inexpensive due to the recent popularization, and the connection of the feedback diodes 503ap to 503cn is different. Need to form.

  That is, in the case of a general-purpose three-phase inverter module that is an IPM, for example, in the case of an FET configuration, as shown in FIG. 11, two FETs 502 ap, 502 an, and FET 502 bp in FIG. Two FETs Q1p, Q1n, FETQ2p, Q2n, FETQ3p, Q3n corresponding to 502bn, FET502cp, 502cn are provided. Provided. In this case, the connection of the feedback diodes D1p to D3n is greatly different from the connection of the feedback diodes 503ap to 503wn of the three-phase inverter 500 of FIG. Therefore, the three-phase inverter unit 500 cannot be formed by an inexpensive general-purpose three-phase inverter module, and this type of conventional motor driving device is expensive.

  As apparent from FIG. 10, both ends of each phase coil 400 are connected to the output side of each phase FET 502ap, 502an, FET 502bp, 502bn, FET 502cp, 502cn of the three-phase inverter unit 500. 100 and the three-phase inverter unit 500 are connected via a total of six power wirings (cables), and the number of wirings is large, and this conventional motor driving device is not only expensive but also large. .

  By the way, the applicant of the present invention has disclosed a soft magnetic stator in which a plurality of concentrated winding coils are wound in the opposite direction to the adjacent coils so that the excitation directions are different from each other in the circumferential direction, and the stator A novel motor having a soft magnetic rotor having a plurality of salient poles formed in the inner circumferential direction has already been invented and applied (Japanese Patent Application No. 2008-323428). When the motor of the already-filed application is also driven by a motor driving device provided with the three-phase inverter unit 500, the motor becomes expensive and the same problem as in the SR motor 1 occurs.

  The present invention is particularly suitable for driving the motor of the already-filed application, and has an inexpensive configuration using a general-purpose three-phase inverter module that is an IPM, and has a small number of wires for power between the motor and the three-phase inverter unit. An object of the present invention is to provide a motor drive device having a novel configuration.

  In order to achieve the above-described object, the motor driving device of the present invention is arranged in such a manner that a plurality of concentrated winding coils are wound in opposite directions to neighboring coils so that the excitation directions are different from each other in the circumferential direction. A motor driving device for driving a motor comprising a soft magnetic stator and a soft magnetic rotor having a plurality of salient poles formed in a circumferential direction inside the stator, between a positive and negative terminal of a DC power supply A bridge side of each phase is connected to each other, the output sides of two switching elements are connected in series to each bridge side, and a diode is connected between the output terminals of both switching elements. And a control unit for turning on and off the switching elements of the three-phase inverter unit, and a connection point between the switching elements on the bridge side of each phase and a neutral point of a star connection, Each of the coils of each phase is provided in between, and by turning on and off each of the switching elements of the control unit, the combination of energizing the coils of each phase every 120 degrees of electrical angle is changed to both adjacent coils, and the electrical angle is 240 degrees. Two-phase energization is performed each time (claim 1).

  In the case of the motor drive device according to the first aspect of the present invention, the three-phase inverter portion can be formed using an inexpensive general-purpose three-phase inverter module that is an IPM. In addition, one end side of each phase coil of the stator is connected to the three-phase inverter unit, but the other end side is connected to the neutral point, so the motor and the three-phase inverter unit are for a total of three power They are connected via wires, the number of wires is halved, and the structure is simple and small.

  And each coil of the phase sequence in the circumferential direction of the stator is wound in the opposite direction to the adjacent coil, and each coil in the phase sequence has a combination of energizing the coils of each phase at every 120 electrical angles. Instead, two-phase energization is performed by 240 electrical angles, and only the adjacent two-phase coils are energized simultaneously by shifting by one phase every 120 degrees of electrical angle, so that the magnetic flux of the two-phase magnetic poles energized and excited by the stator is The salient poles of the rotor are passed in the same direction (polarity), and even if they strengthen each other, they do not cancel each other out, so that the rotor is magnetically attracted and rotated. In this case, the torque / current ratio of the motor is reduced, and the efficiency of the motor and the three-phase inverter is improved.

  Therefore, an inexpensive general-purpose three-phase inverter module can be used, and a configuration in which there are few power wirings connecting the motor and the three-phase inverter unit allows multiple concentrated coils to be excited in the circumferential direction. And a soft magnetic stator that is wound in the opposite direction to the adjacent coil so as to be different from each other, and a soft magnetic rotor in which a plurality of salient poles are formed in the circumferential direction inside the stator. The new motor can be driven, and the new motor can be driven efficiently and stably with an inexpensive and small configuration.

  Next, in order to describe the present invention in more detail, one embodiment will be described in detail with reference to FIGS.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a motor 1 of the present embodiment, FIG. 2 is an explanatory diagram of a short-circuit magnetic path, FIG. 3 is a block diagram of a motor drive device 10, and FIG. 4 is a three-phase inverter section 11 of FIG. FIGS. 5 and 6 are explanatory diagrams of two-phase excitation of the coil 4 of the stator 2 of the motor 1, and FIGS. 7 and 8 are explanatory diagrams of changes in the two-phase excitation state of the coil 4 of the stator 2.

(Motor 1)
In the motor 1 of the present embodiment shown in FIG. 1, reference numeral 2 denotes a cylindrical soft magnetic stator in the motor axial direction, which is located at equally spaced positions (magnetic pole positions) in the circumferential direction on the inner peripheral side of the stator 2. Twelve salient poles 21 forming magnetic poles are formed inward in the radial direction. The salient pole 21 is substantially half of the length of the salient pole 201 of the conventional SR motor 100, and the protrusion of the magnetic pole from the stator 2 to the inner peripheral side is short, so that the inner diameter of the stator 2 is increased accordingly.

  Reference numeral 3 denotes a cylindrical soft magnetic rotor provided coaxially inside the stator 2, and eight salient poles 31 at salient poles 21 at circumferentially spaced positions (magnetic pole positions) on the outer peripheral surface. It is formed radially outward so as to face each other. Since the stator 2 has a large inner diameter, the rotor 3 is formed with a larger diameter to increase the torque.

  Specifically, the stator 2 and the rotor 3 are formed of, for example, a laminated steel plate in which silicon steel plates or the like are stacked in the axial direction of a motor shaft that passes through the center of the rotor 3 or a dust core.

  Next, the stator 2 is formed with a concave (concave groove) outer peripheral slot portion 22 on the opposite side (outer rule side) of each salient pole 21. In addition, a concave (concave groove-shaped) inner peripheral slot portion 23 is formed at a position on the inner peripheral side of the stator 2 that is shifted from each outer peripheral slot 22 by 1/2 pitch of the salient pole interval. In the case of three-phase excitation, the magnetic poles of three phases (indicated by A, B, C or U, V, W, and in this embodiment, U, V, W) are sequentially arranged in the circumferential direction of the stator 2. In order to form, the coil 4 is wound by concentrated winding (toroidal winding) on the outer peripheral slot 22 and the inner peripheral slot 23 of each magnetic pole across the yoke of the stator 2 (the winding direction will be described later). Therefore, one side of the coil 4 of each magnetic pole of the stator 1 is accommodated in the outer peripheral slot portion 22 and the remaining one side is accommodated in the inner peripheral slot portion 23.

  Next, the coil winding direction of the coil 4 of each magnetic pole will be described. The coil winding direction is opposite between adjacent coils 4 in the circumferential direction of the stator 2. In other words, the coil 4 of each magnetic pole is opposite between adjacent magnetic poles. In this case, the magnetic poles are arranged in the order of U, V, W in the circumferential direction of the stator 2 and the polarity of the magnetic poles alternately changes between the N pole (+ sign) and the S pole (-sign). The magnetic poles change counterclockwise in the circumferential direction of the stator 2, for example, U +, V−, W +, U−, V +, W−,. In this case, the magnetic flux of each magnetic pole passes from the stator 2 to the stator 2 through the rotor 3 based on the N magnetic pole and the S magnetic pole that are energized and excited in the stator 2 as shown by the loops of arrows c and d in FIG. Returning, it does not circulate in the stator 2 as shown by the broken line arrow c in FIG. 2, and no short-circuit magnetic flux is generated in the yoke of the stator 2.

  In the motor 1 of this embodiment formed as described above, (1) one side of the coil 4 of each magnetic pole of the stator 2 is disposed in the outer peripheral slot portion 22 on the outer peripheral side of the stator 2, and the remaining one side is the stator 2. In the case of the conventional SR motor 1 or the like, the height of the coil 4 on the inner peripheral side of the stator 2 is reduced (substantially halved) and the salient pole 21 is correspondingly disposed in the inner peripheral slot portion 23 on the inner peripheral side. The protrusion of the magnetic poles from the stator 2 to the inner peripheral side can be shortened to approximately half of the length. Since the protrusion of the magnetic poles of the stator 2 to the rotor 3 side is shortened, the torque can be increased by increasing the diameter of the rotor 3 accordingly.

  (2) Since the outer peripheral slot portion 22 and the outer peripheral surface of the yoke opposite to the position of each magnetic pole of the stator 2 are formed in a concave shape with a 1/2 pitch shift from the inner peripheral slot portion 23 in the circumferential direction, the coil One side of 4 is disposed (accommodated) in the recess of the outer peripheral slot portion 22 and hardly swells outside the stator 2, and the stator 1 can be miniaturized and the motor 1 can be greatly reduced in size. Further, although the coil 4 is disposed in the concave portion of the outer peripheral slot portion 22 and the spread in the circumferential direction of the stator 2 is reduced, each outer peripheral slot portion 22 and each inner peripheral slot portion 23 are displaced in the circumferential direction. The yoke 2 has a large magnetic path cross-sectional area in the circumferential direction, and a sufficient magnetic path can be secured.

  Accordingly, the motor 1 is a new double salient pole type AC motor that is reduced in size and weight by eliminating the bulge (swelling) of the coil 4 toward the outer periphery of the stator while increasing the torque. This is a motor of the present applicant's application that is suitable for a motor or the like.

(Motor drive device 10)
A motor driving apparatus 10 for driving the motor 1 is configured as schematically shown in FIG. 3, and controls to turn on and off a three-phase inverter unit 11 that drives the motor 1 and each switching element (FET) to be described later of the three-phase inverter unit 11. The unit 12 is provided.

  And the three-phase inverter part 11 is comprised as shown in FIG. In FIG. 4, reference numeral 13 denotes a vehicle battery, for example, 111 denotes an energy storage capacitor connected in parallel to the battery 17, and forms a DC power source for the three-phase inverter unit 11 together with the battery 13. 112up and 112un are positive side and negative side FETs (switching elements) of the U-phase bridge side u, and the output side is connected in series with the U-phase coil 4 of the motor 1 interposed therebetween. 112vp and 112vn are positive and negative FETs (switching elements) of the V-phase bridge side v, and the output side is connected in series with the V-phase coil 4 sandwiched between the positive and negative ends of the DC power supply. 112wp and 112wn are FETs (switching elements) on the positive and negative sides of the W-phase bridge side w, and the output side is connected in series with the W-phase coil 4 sandwiched between the positive and negative ends of the DC power supply. In FIG. 4, a plurality of coils 4 connected in series and parallel in each phase are represented by one coil 4, and the connection configuration of the plurality of coils 4 in each phase is omitted.

  113up, 113vp, 113wp are feedback path diodes provided between the output terminals of the FETs 112up, 112vp, 112wp of each phase, 113un, 113vn, 113wn are provided between the output terminals of the FETs 112un, 112vn, 112wn of each phase. This is a diode for the feedback path.

  That is, the three-phase inverter unit 11 has the same configuration as the general-purpose three-phase inverter module 700, which is the IPM in FIG. 11, and can be formed by an inexpensive general-purpose three-phase inverter module. Can be formed.

  Next, the coil 4 of each phase of the motor 1 has a connection point pu of FETs 112up and 112un having a bridge side u on one end side, a connection point pv of FETs 112vp and 112vn on the bridge side v, and a connection point pw of FETs 112wp and 112wn on the bridge side w. And the other end is connected to the neutral point o of the star connection. In this case, the three-phase inverter unit 11 and the motor 1 are connected by three power wires (cables) lu, lv, and lw, so that the number of wires is small and the motor drive device 10 can be downsized. .

  Next, the control unit 12 in FIG. 3 will be described. The control unit 12 has a substantially general configuration of motor servo control. The current command value calculation unit 14 calculates the current command value Ir of the motor 1 based on the required torque command value Tr, and the current command value Ir is three. Based on the output voltage (inverter voltage) Vinv of the phase inverter unit 11, the correction unit 15 corrects the voltage feedback. Further, the corrected current command value Ir * of the correction unit 15 is obtained by each phase current command value calculation unit 17 based on the rotation detection feedback of the rotation detector 16 such as a resolver attached to the motor 1. It is converted into a current command value Irr. Further, an error ΔI between the current command value Irr of each phase and the detected current Id of the current detector 18 of each phase provided in the three-phase inverter unit 11 is calculated by the calculator 19, and a gate pulse is generated based on the error ΔI. By the unit 20, positive side gate pulses Up, Vp, Wp and negative side gate pulses Un, Vn, Wn of U, V, W phases are formed. The gate pulses Up, Vp, Wp and the gate pulses Un, Vn, Wn are supplied as drive pulses to the gates of the positive side FETs 112up, 112vp, 112wp and the negative side FETs 112un, 112vn, 112wn of the three-phase inverter unit 11, respectively. The FETs 112up to 112wn are turned on / off depending on the presence / absence of a drive pulse.

  Then, by turning on and off the FETs 112up to 112wn, the coil 4 of each phase of the motor 1 is energized, and the coils 4 of each phase of U, V, and W are energized every 120 degrees as shown in FIGS. The combination to be performed is changed to each of the coils 4 on both sides, and two-phase energization is performed by 240 degrees in electrical angle to control the energization of the motor 1. The direction of the current of each coil 4 is positive (+) between electrical angles 0 to 180 degrees and negative (-) between electrical angles 180 to 360 degrees. FIG. 5 shows the energization of the coil 4 of each phase with an electrical angle of 0 to 720 degrees by an arrow line, and FIG. 6 shows the currents iu, iv, iw and the phases of the coil 4 of each phase at an electrical angle of 0 to 720 degrees. The solid line represents the current, and the broken line represents the outline of the inductance that varies depending on the facing state of the stator magnetic pole and the rotor magnetic pole.

  When the energization control is performed in this manner, the motor 1 is energized by the coils 4 of each phase because the coils 4 of each phase are wound in opposite directions to the coils 4 adjacent to each other in the circumferential direction and the excitation directions are different from each other. For every 120 degrees of electrical angle, the combination is U phase (+) and V phase (-), U phase (+) and W phase (-), V phase (+) and W phase (-), V phase (+ ) And U phase (-), W phase (+) and U phase (-), W phase (+) and V phase (-), and by repeating these changes with a period of 720 degrees electrical angle 7 and FIG. 8, the field magnetic flux changes and the rotor 3 rotates. In terms of electrical angles based on the U phase, (a), (b), and (c) in FIGS. 7A and 7B are electrical angles in which the two phases U and V are energized and excited with currents + I and −I. 120 degree, W and U two phases are 120-240 degrees energized and excited with currents -I and + I, and V and W two phases are energized and excited with currents + I and -I, showing changes of 240 to 360 degrees. 8, (a), (b), and (c) are the electric angles 360 to 480 degrees, in which the two phases U and V are energized and excited by current -I and + I, and the two phases W and U are current + I, A change of 480 to 600 degrees energized and excited at −I, and two phases V and W of 600 to 720 degrees energized and excited at −I and + I are shown.

  And in the case of the said embodiment, the three-phase inverter part 11 can be formed using the inexpensive general-purpose three-phase inverter module which is IPM, and the motor 1 and the three-phase inverter part 11 are three in total. They are connected via power wiring, the number of wiring is halved, and the structure is simple and small. Further, each coil 4 in the phase sequence in the circumferential direction of the stator 2 is wound in the opposite direction to the adjacent coil, and each coil 4 in the phase sequence is shifted by one phase every 120 degrees of electrical angle and is adjacent to each other in two phases. Since only the two-phase magnetic poles energized and excited by the stator 4 pass through the salient poles of the rotor 3 in the same direction (polarity), they can be reinforced but not cancelled. Thus, the rotor 3 is magnetically attracted and rotates. In this case, the torque / current ratio of the motor 1 is reduced, and the efficiency of the motor 1 and the three-phase inverter unit 11 is improved.

  Therefore, an inexpensive general-purpose three-phase inverter module can be used, and the motor 1 can be driven with a configuration with a small number of power wirings connecting the motor 1 and the three-phase inverter unit 11. With the configuration, the motor 1 having a novel structure can be driven efficiently and stably.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit thereof. For example, the coils 4 of each phase of the motor 1 can be made. The structure for arranging the stator, the shape of the stator 2 and the like may be whatever. Further, the number of coils 4, that is, the number of magnetic poles of the stator 2 and the number of rotors 3 are not limited to the number of the embodiments (12 pieces, 8 pieces).

  Next, each switching element of the three-phase inverter unit 11 is not limited to the FET, and may be formed by another power switching element such as an IGBT. Also. The configuration of the control unit 12 may be any.

  The present invention also provides a stator in which a plurality of concentrated winding (toroidal winding) coils are wound in the circumferential direction in opposite directions so as to have different excitation directions from adjacent coils, and the inside of the stator. The present invention can be applied to a motor driving device that drives three-phase various motors including a rotor having a plurality of salient poles formed in the circumferential direction.

It is sectional drawing which shows the structure of the motor of one Embodiment of this invention. It is explanatory drawing of a short circuit magnetic circuit. It is a block diagram of the motor drive device of one embodiment of the present invention. It is a connection diagram of the three-phase inverter part of FIG. It is explanatory drawing of the electricity supply control of the motor by the motor drive device of FIG. It is explanatory drawing of the electric current change of the coil of each phase of the stator by the electricity supply control of FIG. It is explanatory drawing of an example of the change of the excitation state of the motor of FIG. 1 by the motor drive device of FIG. It is explanatory drawing of the other example of the change of the excitation state of the motor of FIG. 1 by the motor drive device of FIG. It is sectional drawing which shows the structure of the conventional switched reluctance motor. FIG. 10 is a connection diagram of a three-phase inverter unit of a conventional motor driving apparatus that drives the switched reluctance motor of FIG. 9. It is a connection diagram of a general-purpose three-phase inverter module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Stator 3 Rotor 4 Coil 11 Three-phase inverter part 12 Control part 112up-112wn FET
113up to 113wn Feedback diode

Claims (1)

A plurality of concentrated winding coils arranged in the circumferential direction and wound in the opposite direction to the adjacent coils so that the excitation directions are different from each other, and a plurality of stator windings arranged in the circumferential direction inside the stator. A motor drive device for driving a motor including a soft magnetic rotor on which salient poles are formed,
A bridge side of each phase is connected between the positive and negative terminals of a DC power source, the output sides of two switching elements are connected in series to each bridge side, and a feedback diode is connected between the output terminals of both switching elements. A three-phase inverter with a bridge configuration;
A controller that turns on and off each of the switching elements of the three-phase inverter unit;
Each of the coils of each phase is provided between the connection point of both switching elements on the bridge side of each phase and the neutral point of the star connection,
A motor characterized in that, by turning on and off each of the switching elements of the control unit, the combination of energizing the coils of each phase every 120 degrees of electrical angle is changed to each of the adjacent coils to conduct two-phase energization by 240 degrees of electrical angle Drive device.

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