JP5543186B2 - Switched reluctance motor drive system - Google Patents

Description

The present invention includes a rotor having a plurality of convex poles, and a stator having a plurality of magnetic poles arranged inside the rotor and having an excitation coil wound around the convex portion. by successively supplying current to the exciting coil of the plurality of magnetic poles relates to a switched reluctance motor drive system which is adapted to rotate the rotor which is disposed outside the stator.

As an electric motor drive system widely known so far, (1) one constituted by a PWM (Pulse Width Modulation) inverter and a three-phase synchronous motor, and (2) one constituted by a PWM inverter and a three-phase induction motor are known. It has been. These were proposed in the Showa 40's, and are widely used in elevators, electric cars, cranes, air conditioners, electric cars, and hybrid cars due to the development of power electronics and electronic circuit technology. The electric motor system has been popular because of its good controllability over classic electric motor systems. However, in recent years when the importance of CO ₂ reduction and scarce resources has come to be recognized, the ability to follow conventional electric motor drive systems has the following problems.

  The resources of neodymium magnets used for synchronous motors are unevenly distributed in specific countries, and there are not enough quantities to be used for electric motors as drive sources for electric vehicles around the world. In addition, the induction motor has weak points in terms of weight and efficiency, and further decreases in efficiency due to the high frequency of the pseudo sine wave generated by the PWM inverter, and regenerative braking requires a high level of technology. .

In order to greatly reduce CO _2, it is necessary not only to improve the efficiency of electric motor drive systems in all fields including the spread of electric vehicles, but also to increase the energy recovery during braking as much as possible. And in order to spread this worldwide, it is important that the configuration has few resource restrictions.

  The present invention proposes a new motor drive system based on a reluctance motor (see, for example, Patent Document 1), which is a departure from a conventional motor drive system based on a three-phase synchronous motor or a three-phase induction motor. is there.

JP 2007-31562 A

The conventional reluctance motor
Low efficiency, heavy weight,
Regenerative braking is difficult,
There were problems such as torque pulsation, vibration, and loud noise.

  These problems are that the reluctance motor coil is inherently large in reactance, so that it is difficult to control the current quickly, so it is difficult to supply a current having an advantageous waveform from the viewpoint of torque fluctuation to each coil. Is attributed. Further, during regenerative braking, the excitation coil superimposes an original current that generates an attractive force and a regenerative current. However, it is difficult to control the regenerative current to be effectively separated and recovered by the power source. Furthermore, an inward force acts on the outer frame by the suction force, which causes vibration and noise.

The present invention has such has been made in view of the circumstances, can be efficiently driven, it becomes possible to recover the regenerative power, torque pulsation, providing a drive system of a small switched reluctance motor vibration To do.

A drive system for a switched reluctance motor according to the present invention includes a stator on which an exciting coil is mounted, and a rotor disposed so as to surround the stator, and the rotor is disposed coaxially. A plurality of rotor units, and the stator has a plurality of stator units arranged to face the plurality of rotor units, and each of the plurality of rotor units has a predetermined angle. There are 2n (n is an integer) convex poles arranged at intervals, and each of the plurality of stator units has a predetermined gap formed between each convex pole of the corresponding rotor unit. 4n (n is an integer) magnetic poles arranged at a predetermined angular interval, and a first exciting coil is wound around every other of the 4n magnetic poles in each of the plurality of stator units, The first exciting coil A second exciting coil is sequentially wound around the magnetic poles other than the wound magnetic pole, and the relative positions in the rotational direction of the plurality of rotor units and the plurality of stator units are set to be shifted by a predetermined angle. The switched reluctance motor, the DC constant current power supply device, and the plurality of stator units in the switched reluctance motor are respectively provided to switch between the first current path and the second current path. A plurality of current switching circuits; and switching control means for controlling the current switching circuit to alternately conduct the first current path and the second current path. The plurality of current switching circuits are connected in series in a state where the first excitation coil and the second excitation coil provided in the stator unit corresponding to the second current path are connected in series. A DC constant current output from one output terminal of the DC constant current power supply is connected to the first and second current paths of the first stage current switching circuit connected in series, and the final stage The DC constant current flowing through the first exciting coil connected to the first current path and the second exciting coil connected to the second current path of the current switching circuit is the other of the DC constant current power supply devices. The DC constant current power supply device, the plurality of current switching circuits, and the switched reluctance motor are connected so as to be fed back to the output terminal, and the switching control means is arranged at an angular position of the rotor of the switched reluctance motor. Accordingly, the conduction states of the first and second current paths in each of the plurality of current switching circuits are alternately switched, and a rectangular wave current is alternately passed through the first and second exciting coils. The timing for switching the conduction state of the first and second current paths between the driving and braking of the switched reluctance motor is shifted by a rotation time corresponding to an electrical angle of 180 degrees of the rotor. The current switching circuit is controlled .

With such a configuration, in the switched reluctance motor, the first excitation coil and the second excitation coil wound around every other 4n magnetic poles of each of the plurality of stator units constituting the stator. By switching and supplying a rectangular wave DC constant current to each stator unit while shifting by a predetermined timing, 2n salient poles of each of the plurality of rotor units constituting the rotor disposed outside the stator are provided. Are sequentially attracted to the magnetized magnetic poles of the corresponding stator units, so that the rotor is rotated by the attraction force. In this way, the switched reluctance motor can be driven. Further, at the time of braking, opposed to the convex pole of the corresponding rotor unit, which is superimposed on the DC constant current supplied to the first exciting coil and the second exciting coil wound around each magnetic pole of each stator unit. A current corresponding to the change in area can be fed back to the DC constant current power supply device. The current superimposed on the fed back DC constant current can be stored as regenerative power.

  In the switched reluctance motor according to the present invention, the integer n is 2 or more, each of the plurality of rotor units has four or more convex poles, and each of the plurality of stator units is It can be set as the structure which has 8 or more magnetic poles.

  With such a configuration, each stator unit constituting the stator has eight or more magnetic poles. Therefore, when the first exciting coil and the second exciting coil are energized alternately, two sets of 1 Since every other four or more magnetic poles are excited alternately, the force due to the excitation is less biased during the drive, and acts on each stator unit, thereby suppressing vibration during the drive. become able to.

  Further, in the switched reluctance motor according to the present invention, the relative position in the rotation direction of the plurality of rotor units and the plurality of stator units is determined by setting the pitch angle of the magnetic poles of the stator unit to the plurality of rotor units. It can be set as the structure set so that it may shift | deviate by the angle divided by the number of.

  With such a configuration, one pitch of the magnetic poles of each of the plurality of stator units constituting the stator is shared by the plurality of rotor units, so that smoother rotation is possible.

  In the switched reluctance motor according to the present invention, the plurality of rotor units may be fixed at the same angular relationship in the rotation direction.

  In this case, the plurality of stator units constituting the stator with respect to the rotor are arranged so as to be shifted by a predetermined angle.

  Furthermore, in the switched reluctance motor according to the present invention, the plurality of stator units may be arranged with the same angular relationship in the rotational direction.

  In this case, the plurality of rotor units constituting the rotor are arranged so as to be shifted by a predetermined angle.

  Further, in the switched reluctance motor according to the present invention, the ratio of the width in the rotation direction of each magnetic pole of each of the plurality of stator units to the width in the rotation direction of each convex pole of each of the plurality of rotor units is less than 1. It can be set as the structure set to the predetermined | prescribed ratio.

  With this configuration, the width in the rotation direction of each of the plurality of rotor units is larger than the width in the rotation direction of each magnetic pole of the corresponding stator unit. Since the period during which the stator unit is not opposed to the magnetic pole of the stator unit can be made shorter, the period during which the attractive force from each magnetic pole of the stator unit with respect to each convex pole of the rotor unit is interrupted becomes shorter. Therefore, torque fluctuation and vibration can be reduced.

In switched reluctance motor according to the present invention, a rectangular wave into a first exciting coil and the second exciting coil wound on every other one of a plurality of stator units each the 4n magnetic poles constituting the stator By switching and supplying DC constant current to each stator unit while shifting by a predetermined timing, 2n convex poles of each of the plurality of rotor units constituting the rotor arranged outside the stator can be handled. Since the rotor is rotated by being sequentially attracted to the magnetized magnetic poles of the stator unit to be driven, efficient driving with less torque pulsation and vibration becomes possible.

  Further, according to the switched reluctance motor drive system according to the present invention, the first excitation coil and the second excitation coil wound around the 4n magnetic poles of the plurality of stator units constituting the stator. A switched reluctance motor can be driven by supplying a rectangular-wave DC constant current while alternately switching, and a first exciting coil wound around each magnetic pole of each stator unit during braking Since the current corresponding to the change in the area facing the convex pole of the corresponding rotor unit superimposed on the DC constant current supplied to the second exciting coil can be fed back to the DC constant current power supply device, the switch The regenerative power can be recovered along with the driving of the reluctance motor.

  Furthermore, the switched reluctance motor according to the present invention has a structure in which the rotor is arranged outside the stator and can be used as a so-called in-wheel motor of an electric vehicle, and thus obtains the following effects in particular. Can do.

  Since the gap (magnetic pole gap) between each magnetic pole of each stator unit and the convex pole of each rotor unit can be arranged more outward, the substantial radius of rotation can be increased for low speed operation. The efficiency drop can be reduced. As a result, the gearless mechanism can be operated at a low speed.

  Further, by arranging the magnetic pole gap portion outward, it is easy to make a multipolar structure, and it is easy to reduce the weight of the yoke by reducing the cross section of the yoke.

  The switched reluctance motor according to the present invention can be easily used as a gearless in-wheel motor by integrating the rotor with the rim of the wheel, assuming application to an electric vehicle. .

It is a block diagram which shows the basic composition of the switched reluctance motor drive system which concerns on one Embodiment of this invention. It is sectional drawing which shows the cross-sectional structure seen from the horizontal direction of the switched reluctance motor which concerns on one Embodiment of this invention. It is sectional drawing which shows the cross-section in the AA line of the switched reluctance motor shown to FIG. 2A. A first rotor unit and a first stator at a reference rotational position of a rotor composed of four rotor units with different rotational phases arranged with respect to a stator composed of four stator units having a fixed rotational phase It is a figure which shows the arrangement | positioning relationship with a unit. The second rotor unit and the second rotor at the reference rotational position of the rotor composed of four rotor units with different rotational phases arranged with respect to the stator composed of four stator units having a fixed rotational phase It is a figure which shows the arrangement | positioning relationship with a unit. A third rotor unit and a third stator at a reference rotation position of a rotor composed of four rotor units with different rotational phases arranged with respect to a stator composed of four stator units having a fixed rotational phase It is a figure which shows the arrangement | positioning relationship with a unit. A fourth rotor unit and a fourth stator at a reference rotational position of a rotor composed of four rotor units with different rotational phases arranged with respect to a stator composed of four stator units having a fixed rotational phase. It is a figure which shows the arrangement | positioning relationship with a unit. The first rotor unit and the first rotor unit at the reference rotation position of the rotor composed of four rotor units having the same rotational phase arranged with respect to the stator composed of four stator units having different rotational phases. It is a figure which shows the arrangement | positioning relationship with a stator unit. The second rotor unit and the second rotor unit at the reference rotation position of the rotor composed of four rotor units having the same rotational phase set with respect to the stator composed of four stator units having different rotational phases. It is a figure which shows the arrangement | positioning relationship with a stator unit. The third rotor unit and the third rotor unit at the reference rotation position of the rotor composed of four rotor units having the same rotational phase set for the stator composed of four stator units whose rotational phases are shifted. It is a figure which shows the arrangement | positioning relationship with a stator unit. The fourth and fourth rotor units at the reference rotation position of the rotor composed of four rotor units with the same rotational phase arranged with respect to the stator composed of four stator units whose rotational phases are shifted. It is a figure which shows the arrangement | positioning relationship with a stator unit. It is a figure which shows the connection relation of the exciting coil wound around each stator unit of a stator, and the state of the magnetic flux which generate | occur | produces. It is a figure which shows the specific structural example of a current switch. It is a timing chart which shows operation | movement of each switching element in the current switching device at the time of driving a switched reluctance motor. It is a timing chart which shows operation | movement of each switching element in the current switching device at the time of braking a switched reluctance motor. It is a figure which shows each constant current flip-flop circuit (current switching circuit) which comprises a current switch. FIG. 9 is a waveform diagram showing various current waveforms of an exciting coil and a charging voltage waveform of a capacitor in the constant current flip-flop circuit (current switching circuit) shown in FIG. 8. It is a figure which shows the relative positional relationship (the 1) with respect to the stator unit of each rotor unit rotating at the time of a drive. It is a figure which shows the relative positional relationship (the 2) with respect to the stator unit of each rotor unit rotating at the time of a drive. It is a figure which shows the relative positional relationship (the 3) with respect to the stator unit of each rotor unit rotating at the time of a drive. It is a wave form diagram which shows the electric current waveform which flows into the A phase exciting coil and B phase exciting coil wound around each stator unit. It is a figure which shows the relative positional relationship (the 1) with respect to the stator unit of each rotor unit rotating at the time of braking. It is a figure which shows the relative positional relationship (the 2) with respect to the stator unit of each rotor unit rotating at the time of braking. It is a figure which shows the relative positional relationship (the 3) with respect to the stator unit of each rotor unit rotating at the time of braking. It is a figure which shows the dimensional relationship of each stator unit and a rotor unit, and the magnetic circuit formed among them. It is a figure which shows the distribution state (the 1) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of a drive, and the magnetic pole of a stator unit. It is a figure which shows the distribution state (the 2) of the magnetic flux formed in the gap between the convex pole of the rotating rotor unit at the time of a drive, and the magnetic pole of a stator unit. It is a figure which shows the distribution state (the 3) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of a drive, and the magnetic pole of a stator unit. It is a figure which shows the distribution state (the 4) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of a drive, and the magnetic pole of a stator unit. It is a figure which shows the change of the magnetic flux which arises when a rotor unit rotates as shown to FIG. 14A-FIG. 14D, and the electromotive force and torque which generate | occur | produce based on it. It is a figure which shows the distribution state (the 1) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of braking, and the magnetic pole of a stator unit. It is a figure which shows the distribution state (the 2) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of braking, and the magnetic pole of a stator unit. It is a figure which shows the distribution state (the 3) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of braking, and the magnetic pole of a stator unit. It is a figure which shows the distribution state (the 4) of the magnetic flux formed in the gap between the convex pole of the rotor unit which rotates at the time of braking, and the magnetic pole of a stator unit. It is a figure which shows the change of the magnetic flux produced when a rotor unit rotates as shown to FIG. 16A-FIG. 16D, and the electromotive force and torque which generate | occur | produce based on it. It is a circuit diagram which shows the equivalent circuit of the drive system at the time of a drive. It is a circuit diagram which shows the equivalent circuit of the drive system at the time of braking. It is a circuit diagram which shows the equivalent circuit of the drive system at the time of a stop. Time for each phase (corresponding to one rotor unit and one stator unit) at the magnetic pole shortening rate K (see FIG. 13) = 0.75, and the combined torque (synthetic electromotive force) obtained by combining them FIG. It is a figure which shows the time fluctuation | variation of the torque for each phase in magnetic pole shortening rate K (refer FIG. 13) = 0.5, and the synthetic | combination torque which synthesize | combined them. It is a figure which shows the time fluctuation | variation of the torque for each phase in magnetic pole shortening rate K (refer FIG. 13) = 0.8, and the synthetic | combination torque which synthesize | combined them. It is a figure which shows the time fluctuation | variation of the torque for each phase in magnetic pole shortening rate K (refer FIG. 13) = 0.7, and the synthetic | combination torque which synthesize | combined them. It is a figure which shows the force (attraction | suction force) which acts on each stator unit when the A phase excitation coil is excited.

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

  The basic configuration of a switched reluctance motor drive system according to an embodiment of the present invention is as shown in FIG. In FIG. 1, the switched reluctance motor drive system includes a DC constant current power supply device 10, a current switching device 20, and a switched reluctance motor 30. The DC constant current power supply apparatus 10 outputs a DC constant current having a value corresponding to a command from a control system (not shown). As will be described later, the current switcher 20 alternately supplies the DC constant current from the DC constant current power supply device 10 to the two excitation coils (stator side) of the switched reluctance motor 30 in a rectangular waveform. In the switched reluctance motor 30, the rotor fixed to the rotating shaft is rotated by a DC constant current that is supplied in a rectangular waveform to two excitation coils at a predetermined timing. Hereinafter, a switched reluctance motor drive system according to an embodiment of the present invention will be described in detail.

  The switched reluctance motor 30 is configured as shown in FIGS. 2A and 2B. 2A shows a cross-sectional structure as viewed from the side of the switched reluctance motor 30, and FIG. 2b shows a cross-sectional structure taken along the line AA of the switched reluctance motor 30 shown in FIG. 2A.

  2A and 2B, the two rotating plates 302 and 303 are rotatably attached to the support shaft 306 via bearings 304 and 305 fixed at the center thereof. The stator 31 is fixed to the support shaft 306 by a stator stopper 307 made of a nonmagnetic material. The rotor 31 is composed of four stator units 31a, 31b, 31c, and 31d formed of a ferromagnetic laminated steel plate, and these four stator units 31a, 31b, 31c, and 31d are formed of a nonmagnetic material. The spacer is fixed to the support shaft 306 while being held at a predetermined interval by the spacer.

  The rotor 33 is fixed to the two rotating disks 302 and 303 so as to surround the stator 31 described above, and the rotor 33 can rotate about the support shaft 306 together with the two rotating plates 302 and 303. Yes. The rotor 33 is composed of four rotor units 33a, 33b, 33c, and 33d formed of ferromagnetic laminated steel plates, and the four rotor units 33a, 33b, 33c, and 33d are the stators described above. The unit 31a, 31b, 31c, 31d is fixed to the two rotating plates 302, 303 by a fixing bolt 308 while being held at a predetermined interval by a spacer formed of a non-magnetic material.

  An angular position detector 309 is provided at a portion of the support shaft 306 protruding from one rotating plate 303. The angular position detector 309 detects the rotational angular position of the rotating rotating plate 303 and outputs a detection signal corresponding to the detected rotational angular position.

  The four stator units 31a, 31b, 31c and 31d constituting the stator 31 are equiangular with the outer peripheral surface of the annular yoke fitted into the support shaft 306, as shown for the stator unit 31a on behalf of FIG. 2B. Eight (4n: n = 2) magnetic poles 311, 312, 313, 314, 315, 316, 317, 318 are arranged at intervals. Around these magnetic poles 311 to 318, exciting coils 321, 322, 323, 324, 325, 326, 327, and 328 are wound. Four excitation coils 321, 323, 325, and 327 wound around every other magnetic pole 311, 313, 315, 317 of the eight magnetic poles 311 to 318 of the stator unit 31 a (31 b, 31 c, 31 d) are connected in series. Connected and configured as an A-phase excitation coil 32a (A) (32b (A), 32c (A), 32d (A)) (first excitation coil). The four exciting coils 322, 324, 326, and 328 wound around the remaining magnetic poles 312, 314, 316, and 318 are also connected in series, and the B-phase exciting coils 32a (B) (32b (B) and 32c (B) , 32d (B)) (second excitation coil).

  Each of the A phase excitation coil 32a (A) and the B phase excitation coil 32a (B) has an input / output terminal, and the winding direction thereof will be described later (Note that the A phase excitation coil 32a (A) and the B phase excitation coil are described later). The connection of the four exciting coils constituting each of 32a (B) may be a parallel connection as long as the conditions are completely the same in terms of electromagnetic dynamics).

  As described above, in the structure of the switched reluctance motor 30 described above, the number of magnetic poles of each of the stator units 31a to 31d of the stator 31 is eight and the four stator units 31a to 31d are overlapped. Such a structure is referred to as an “8-pole quadruple-phase” structure.

  The four rotor units 33a, 33b, 33c, and 33d constituting the rotor 33 are arranged at equal angular intervals on the inner peripheral surface of the annular yoke as shown for the rotor unit 33a on behalf of FIG. 2B. , Four (2n: n = 2) convex poles 331, 332, 333, 334, which are half the number of magnetic poles of each stator unit. The stator 31 and the rotor 33 are arranged in a predetermined relationship between the tips of the magnetic poles 311 to 318 of the stator units 31a to 31d and the tips of the convex poles 331 to 334 of the rotor units 33a to 33d. The arrangement relationship is such that a gap (magnetic gap) is formed.

  The arrangement relationship between the four stator units 31a to 31d and the four rotor units 33a to 33d is, for example, as shown in FIGS. 3A to 3D.

  When the rotor 33 is at a certain angular position (for example, a reference angular position), the rotor unit 33a is in a position where the convex pole 331 faces the magnetic pole 311 of the stator unit 31a as shown in FIG. 3A. As shown in FIG. 3B, the next rotor unit 33b has an angle of 1 / number of convex poles (= 4) of one magnetic pole angle pitch 45 degrees (electrical angle 180 degrees) from the position shown in FIG. 3A = As shown in FIG. 3C, the next rotor unit 33c is located at the angle (= 11.25 degrees) from the position shown in FIG. 3A. As shown in FIG. 3D, the next rotor unit 33d is located at a position deviated from the rotational direction by a double angle (= 22.5 degrees). = 3 times the angle (33.75 degrees) In it deviated in the direction opposite to the direction of rotation position. As described above, the four stator units 31a, 31b, 31c, 31c constituting the stator 31 are arranged at the same angular relationship, while the four rotor units 33a, 33b, 33c constituting the rotor 33 are arranged. , 33d are arranged at positions shifted by a predetermined angle (= 11.25 degrees) in the direction opposite to the rotation direction with respect to the corresponding stator units 31a, 31b, 31c, 31c.

  Further, the positional relationship between the four stator units 31a to 31b and the four rotor units 33a to 33d can be set, for example, as shown in FIGS. 4A to 4D.

  In this case, when the rotor 33 is at a certain angular position (for example, a reference angular position), in the stator unit 31a, as shown in FIG. 4A, the magnetic pole 311 faces the convex pole 331 of the rotor unit 33a. As shown in FIG. 4B, the next stator unit 31b is located at a position, and is 1 / number of convex poles (= 4) of one magnetic pole angle pitch 45 degrees (electrical angle 180 degrees) from the position shown in FIG. 4A. The angle is 11.25 degrees, and the next stator unit 31c has the angle (= 11.25 degrees) from the position shown in FIG. 4A, as shown in FIG. 4C. As shown in FIG. 4D, the next stator unit 31d is located at a position shifted by a double angle (= 22.5 degrees) from the position shown in FIG. 4A. Rotation by 3 times the angle (33.75 degrees) Located at a position shifted in the direction. As described above, the four rotor units 33a, 33b, 33c, and 33c constituting the rotor 33 are arranged at the same angular relationship, while the four stator units 31a, 31b, and 31c constituting the stator 31 are arranged. , 31d are arranged at positions shifted by a predetermined angle (= 11.25 degrees) in the rotation direction with respect to the corresponding rotor units 33a, 33b, 33c, 33c.

  Referring to FIG. 5, the winding directions of the A-phase excitation coil 32a (A) and the B-phase excitation coil 32b (A) wound around the eight magnetic poles 311 to 318 of the stator units 31a to 31d in the stator 31 are referred to. I will explain.

  A phase excitation coil 32a (A) (32b (A), 32c (A), which is wound around every other magnetic pole 311, 313, 315, 317 of the eight magnetic poles 311-318 of each stator unit 31a-31d. 32d (A)), for example, when a current flows from the input terminal to the output terminal, a magnetic flux is generated from the outside to the inside at the opposing magnetic pole 311 and the magnetic pole 315, and at the inside of the opposing magnetic pole 313 and the magnetic pole 317. Four magnetic circuits (see broken line arrows in FIG. 5) are formed so as to generate a magnetic flux from the outside to the outside. The winding direction of the A-phase exciting coil 32a (A) (32b (A), 32c (A), 32d (A)) is set so that such four magnetic circuits are formed.

  Further, B-phase exciting coils 32a (B) (32b (B), 32c (B) wound around every other magnetic pole 312, 314, 316, 318 of the eight magnetic poles 311-318 of each of the stator units 31a-31d. ), 32d (B)), for example, when a current is passed from the input terminal to the output terminal, for example, the opposing magnetic pole 312 and magnetic pole 316 generate magnetic fluxes from the outside to the inside, and the opposing magnetic pole 314 and magnetic pole 318 are opposed to each other. Generates a magnetic flux from the inside to the outside. The winding direction of the B-phase excitation coil 32a (B) (32b (B), 32c (B), 32d (B)) is such that four such magnetic circuits (see broken line arrows in FIG. 5) are formed. Is set.

  In the switched reluctance motor 30 according to the present embodiment, as described above, a total of four sets of two-phase exciting coils (A-phase exciting coil and B-phase exciting coil) with respect to the four stator units 31a to 31d. (Quadruple phase) The structure is provided.

  The current switcher 20 is configured as shown in FIG. 6, for example.

  The current switching device 20 shown in FIG. 6 includes four constant current flip-flip circuits (currents) provided corresponding to the four stator units 31a, 31b, 31c, and 31d constituting the stator 31 in the switched reluctance motor 30. Path switching circuit) 20a, 20b, 20c, 20d. The first constant current flip-flop circuit 20a corresponding to the stator unit 31a includes a first current path 210a including a first switching element 211a (semiconductor switch) and diodes 212a and 213a, a second switching element 221a (semiconductor switch), and And a second current path 220a including diodes 222a and 223a. The first current path 210a and the A phase excitation coil 32a (A) of the stator unit 31a are connected in series, and the second current path 220a and the B phase excitation coil 32a (B) of the stator unit 31a are connected in series. Has been. Further, a capacitor which is a circuit element for commutation described later between a connection point between the two diodes 212a and 213a in the first current path 210a and a connection point between the two diodes 222a and 223a in the second current path 220a. 230a is connected.

  Similarly to the first constant current flip-flop circuit 20a, the second constant current flip-flop circuit 20b corresponding to the stator unit 31b includes the first current path 210b including the first switching element 211b and the diodes 212b and 213b, A second current path 220b including a switching element 221b and diodes 222b and 223b. The first current path 210b and the second current path 220b are connected to the A phase excitation coil 32b (A) and the B phase excitation of the stator unit 31b. Coils 32b (B) are connected in series. Further, the third constant current flip-flop circuit 20c and the fourth constant current flip-flop circuit 20d corresponding to the stator unit 31c and the stator unit 31d are also the first constant current flip-flop circuit 20a and the second constant current flip-flop circuit 20b. Similarly, the first current paths 210c and 210d including the first switching elements 211c and 211d and the diodes 212c, 213c, 212d and 213d, and the second current including the second switching elements 221c and 221d and the diodes 222c, 223c, 222d and 223d are included. Two current paths 220c and 220d. The first current paths 210c and 210d and the second current paths 220c and 220d are connected to the A-phase excitation coils 32c (A), 32d (A) and B of the stator units 31c and 31d. Phase excitation coils 32c (B), 32d ( ) Are connected in series, respectively.

  Further, in each constant current flip-flop circuit 20b (20c, 20d), as in the first constant current flip-flop circuit 20a, two diodes 212b, 213b {(212c, 213c) of the first current path 210b (210c, 210d). ), (212d, 213d)} and a connection point between the two diodes 222b, 223b {(222c, 223c), (222d, 223d)} of the second current path 220b (220c, 220d). Capacitors 230b, (230c, 230d), which are circuit elements for commutation, are connected.

  The first switching element 211a and the second switching element 221a of the first constant current flip-flop circuit 20a located in the first stage are connected to one output terminal T1 of the DC constant current power supply device 10. Further, the A phase excitation coil 32a (A) and the B phase excitation coil 32a (B) of the stator unit 31a connected to the first current path 210a and the second current path 220a of the first constant current flip-flop 20a are connected. It is connected to the first switching element 211b and the second switching element 221b of the second constant current flip-flop circuit 20b in the next stage via the point T2. The A-phase excitation coil 32b (A) and the B-phase excitation coil 32b (B) of the stator unit 31b connected to the first current path 210b and the second current path 220b of the second constant current flip-flop 20b are connected to the connection point T3. Are connected to the first switching element 211c and the second switching element 221c of the third constant current flip-flop circuit 20c in the next stage, and the first current path 210c and the second current path 220c of the third constant current flip-flop circuit 20c are connected. A phase exciting coil 32c (A) and B phase exciting coil 32c (B) of the stator unit 31c connected to the first switching element of the fourth constant current flip-flop circuit 20d at the final stage via the connection point T4. 210d and the second switching element 220d. Further, the A-phase excitation coil 32d (A) and the B-phase excitation coil 32d (B) of the stator unit 31d connected to the first current path 210d and the second current path 220d of the fourth constant current flip-flop circuit 20d, The DC constant current power supply device 10 is connected to the other output terminal T5.

  The DC constant current power supply device 10 does not depend on the positive / negative, large / small of the load electromotive force appearing in the current switching device 20, and maintains a constant DC current corresponding to the commanded constant current set value. It is configured to output in the direction (from the output terminal T1). In the current switching device 20 having the above-described configuration, the DC constant current output from the output terminal T1 of the DC constant current power supply device 10 is the first constant current flip-flop 20 circuit a and the A phase excitation coil of the stator unit 31a. 32a (A) or B phase excitation coil 32a (B), connection point T2, second constant current flip-flop circuit 20b, A phase excitation coil 32b (A) or B phase excitation coil 32b (B) of stator unit 31b, Connection point T3, third constant current flip-flop circuit 20c, phase A excitation coil 32c (A) or phase B excitation coil 32c (B) of stator unit 31c, connection point T4, fourth constant current flip-flop circuit 20d, and Output terminal of the DC constant current power supply 10 via the A phase excitation coil 32d (A) or the B phase excitation coil 32d (B) of the stator unit 31d It is adapted to return to the 5.

  The flip-flop control circuit 61 (switching control means) is based on angular position information representing a relative angular position of the rotating plate 303 (rotor 33) with respect to the stator unit 31a based on a detection signal from the angular position detector 309. Thus, an operation signal for turning on and off the first switching element 211a and the second switching element 221a in the first constant current flip-flop 20a is output, and the rotor 33 based on the detection signal from the angular position detector 309 is output. Based on the angular position information representing the relative angular position of the first to the second stator unit 31b, an operation signal for turning on and off the first switching element 211b and the second switching element 221b in the second constant current flip-flop 20b is generated. Output. Further, the flip-flop control circuit 61 generates a third constant current flip-flop based on the angular position information representing the relative angular position of the rotor 33 with respect to the stator portion 31c based on the detection signal from the angular position detector 309. 20c outputs an operation signal for turning on and off the first switching element 211c and the second switching element 221c, and relative to the stator unit 31d of the rotor 33 based on the detection signal from the angular position detector 309. On the basis of the angular position information representing the correct angular position, an operation signal for turning on and off the first switching element 211d and the second switching element 221d in the fourth constant current flip-flop 20d is output. Further, when a braking command from another control system (not shown) is input to the flip-flop control circuit 61, the output timing of the operation signal is determined so that the rotor 33 corresponds to an electrical angle of 180 ° from the output timing at the time of driving. Shift the time for rotation.

  When the switched reluctance motor 30 is driven, as shown in FIG. 7A, the first switching element 211a and the second switching element 221a of the first constant current flip-flop circuit 20a are controlled by the flip-flop control circuit 61 (switching control means). ON / OFF operation, ON / OFF operation of first switching element 211b and second switching element 221b of second constant current flip-flop circuit 20b, first switching element 211c and second switching of third constant current flip-flop circuit 20c The on / off operation of the element 221c and the on / off operation of the first switching element 211d and the second switching element 221d of the fourth constant current flip-flop circuit 20d are sequentially 180 degrees / 4 = 45 degrees (electrical angle). Repeatedly with phase difference. When braking the switched reluctance motor 30, the first switching elements of the constant current flip-flop circuits 20a, 20b, 20c, and 20d are controlled by the flip-flop control circuit 61 (switching control means) as shown in FIG. 7B. The turn-on / off operations of 211a, 211b, 211c, 211d and the second switching elements 221a, 221b, 221c, 221d are sequentially 180 degrees / 4 in a state where the phases are shifted 180 degrees (electrical angle) as a whole from the driving timing. = It is repeatedly performed with a phase difference of 45 degrees (electrical angle).

  With reference to FIGS. 8 and 9, the commutation operation in each constant current flip-flop circuit 20a, 20b, 20c, 20d in the current switcher 20 will be described. The current switcher 20 has four constant current flip-flop circuits 20a, 20b, 20c, and 20d. The commutation operation of each of them is shifted by a phase difference of 180 degrees / 4 (electrical angle). FIG. 8 shows only one constant current flip-flop circuit to which a DC constant current is supplied from the DC constant current power supply device 10 together with the DC constant current power supply device 10. The commutation operations in the constant current flip-flop circuits 20a, 20b, 20c, and 20d represented by one constant current flip-flop circuit shown in FIG. 8 are all the same.

  FIG. 9A shows a current waveform during a period from when the current of the A-phase exciting coil 32 (A) connected to the constant current flip-flop in FIG. 8 is turned on to when it is turned off. FIG. 9B shows a current waveform during a period from when the current of the B-phase excitation coil 32 (B) is turned off to when it is next turned on. FIG. 9C shows the capacitor 230, the diode 213, and the A phase excitation during the current switching transient period in which the current of the A phase excitation coil 32 (A) is turned off and the current of the B phase excitation coil 32 (B) is turned on. The waveform of the electric current i which circulates through the coil 32 (A), the B phase excitation coil 32 (B), and the diode 223 is shown. Although the circulating current i is shown to flow in the reverse direction through the diode 223, the circulating current i is canceled out with the backflow constant current flowing through the diode 223, so that only the forward current actually exists in the diode 223. FIG. 9D shows a charging voltage waveform of the capacitor 230 by the circulating current i. In FIG. 9D, the polarity of the capacitor 230 is reversed in the reverse direction after the commutation period ends. The charging voltage of the capacitor 230 is held until the next commutation without being discharged by the diodes 212, 213, 222, and 223.

The cycle of the on / off operation of the current flowing through the A excitation coil 32 (A) and the B phase excitation coil 32 (B) is performed at a rectangular wave fundamental frequency f as shown in FIG. The rise and fall of the on / off operation is performed at the commutation equivalent frequency f ₀ shown by the dotted line in FIG. The rectangular wave fundamental frequency f depends on the number of exciting coil poles P and the rotational speed N (per second) in the switched reluctance motor 30 (see FIGS. 2A and 2B).
f = P / 2 × N (1)
It is represented by The commutation equivalent frequency f ₀ is a concept that depends on the current switching speed in the constant current flip-flop (current switching circuit), and an appropriate value is selected in the range of f <f ₀ as described later.

The voltage generated in the capacitor 230, can be calculated as a reactance voltage drop of the A excitation coil 32 by a sinusoidal current commutation equivalent frequency f ₀ which is the peak value of the DC constant current value (A), the capacitor voltage E _s is
E _s = 2πf ₀ LI (2)
It is represented by However, L is the reactance of the A-phase excitation coil 32 (A) (B-phase excitation coil 32 (B)). The reactance L is the sum of the reactance of the A excitation coil 32 (A) and the reactance of the B phase excitation coil 32 (B). However, in the portion where the magnetic pole and the convex pole do not face each other, the reactance L is effectively an air core coil. What is necessary is to consider one magnetic pole facing each other with a predetermined gap length.

  The drive torque will be described with reference to FIGS. 10A to 10C and FIG. The rotation of the rotor 33 is based on the clockwise direction in each figure. 10A to 10C show the relationship between the stator unit 31a and the corresponding rotor unit 33a, the other stator units 31b, 31c, and 31d and the corresponding rotor units 33b and 33c. , 33d is the same.

Figure 10A is a rotation direction front end P-salient 331 of the rotor unit 33a is, show a state close to the upstream end point to Q ₁ pole 311 of the stator unit 31a, 10B are salient rotor unit 33a FIG. 10C shows a state in which the rotation direction tip P of 331 is close to the downstream end point Q2 of the magnetic pole 311 of the stator unit 31a, and FIG. 10C shows the rotation direction tip P of the convex pole 331 of the rotor unit 33a. A state in which the magnetic pole 312 adjacent to 311 is close to the upstream end point Q ₃ is shown. FIG. 10A to FIG. 10C show switching of excitation of the magnetic pole 311 by the excitation coil 321 (A-phase excitation coil 32 (A)) and excitation of the magnetic pole 312 by the excitation coil 322 (B-phase excitation coil 32 (B)). In order, the rotor unit 33a rotates by one pole pitch of the stator unit 31a.

  The A-phase excitation coil 32 (A) and the B-phase excitation coil 32 (B) are switched to the state shown in FIG. 11 by alternately switching the first switching element 211 and the second switching element 221 in the constant current flip-flop circuit. The rectangular wave direct current constants as shown alternately flow.

More specifically, in a position upstream end point to Q ₁ pole 311 is opposed in the rotational direction leading P and stator units 31a-salient 331 on the rotor unit 33a as shown in FIG. 10A, the current to the exciting coil (see time t1 in FIG. 11) said transfer flow is complete commutated to the a-phase side, then, is the downstream end point Q ₂ in the rotational direction leading end P and the magnetic poles 311-salient 331 as shown in FIG. 10B At the opposite position, the current to the exciting coil starts to commutate to the B-phase side (see time t2 in FIG. 11), and further, as shown in FIG. 10C, the rotation direction tip P of the convex pole 311 and the next magnetic pole at a position where the upstream-side end point Q ₃ facing the 312, the (see time t3 in FIG. 11) commutation is completed to the B-phase side as a first switching element 211 in the constant current flip-flop circuit 2 switching of the on-off switching element 221 is adapted to be made.

  Thus, during the transition from the state shown in FIG. 10A to the state shown in FIG. 10B, the convex pole of the rotor unit 31a is generated by the force from the magnetic pole 311 excited by the exciting coil 321 (A-phase exciting coil 32 (A)). 331 is sucked and generates torque in the forward direction. In the period of transition from the state shown in FIG. 10B to the state shown in FIG. 10C, the current of the excitation coil 321 (A-phase excitation coil 32 (A)) decreases and the excitation coil 322 (B-phase excitation coil 32 (B) ) During which the current increases. The width in the rotation direction of each convex pole of the rotor unit 31a is set larger than the width of each magnetic pole of the stator unit 33a, and the state in which the entire width of the excitation pole faces the convex pole is maintained. In the period (commutation period) in which the state shown in FIG. 10B is changed to the state shown in FIG. Further, the attractive force caused by the rising current of the B-phase exciting coil 32 (B) (exciting coil 322) is not rotated by the other convex poles in the vicinity of the rotor unit 33a. No adverse effect.

In this way, during the period of transition from the state of FIG. 10A to the state shown in FIG. 10B, the set maximum current flows to the A-phase excitation coil 32 (A) (excitation coil 321), and an effective torque is generated. This effective torque is generated even when the excitation current is switched to the B-phase excitation coil 32 (B) (excitation coil 322). Of the period P point of each salient pole in the rotor unit 33a is moved to the Q ₃ points from Q ₁ point of the pole, the period of moving from _one point Q to Q ₂ points, torque and the load electromotive force is generated. Magnetic pole shortening rate K is
(Angle between Q1 and Q2) / (Angle between Q1 and Q3) = K (3)
Defined according to

  Note that the torque and electromotive force of the switched reluctance motor 30 as a whole include the total number of convex poles 4 in each rotor unit and the number of multiple phases (rotor units and stators) as estimated as described above. The number of units is 4).

  The generation of regenerative torque will be described with reference to FIGS. 12A to 12C. 12A to 12C show the relationship between the stator unit 31a and the corresponding rotor unit 33a, but the other stator units 31b, 31c, and 31d and the corresponding rotor units 33b and 33c. , 33d is the same.

Figure 12A is a rotation direction rear end P-salient 331 of the rotor unit 33a is, show a state close to the upstream end point to Q ₁ pole 311 of the stator unit 31a, 12B are convex rotor unit 33a rotation direction rear end P of the pole 331 indicates a state close to the downstream end point Q ₂ pole 311 of the stator unit 31a, FIG. 12C, the rotation direction rear end P-salient 331 of the rotor unit 33a is, shows a state close to the upstream end point Q ₃ pole 312 next to the poles 311 of the stator unit 31a. The angular position of the rotor unit 33a shown in FIG. 12A to FIG. 12C is equal to the width of the convex pole, that is, 360 degrees / 8 (geometric angle) and 180 degrees, respectively, as compared with those shown in FIG. 10A to FIG. (Electrical angle) is delayed.

In the position where the upstream-side end point to Q ₁ pole 311 in the direction of rotation the rear end P and the stator unit 31a-salient 331 on the rotor unit 33a is opposed as shown in FIG. 12A, the current to the exciting coil, A phase side commutated said transfer flow is completed (see time t1 in FIG. 11), then the position where the downstream-side end point Q ₂ facing the rotational direction rear end P and the magnetic poles 311-salient 331 as shown in FIG. 12B Then, the current to the exciting coil starts to commutate to the B-phase side (see time t2 in FIG. 11), and further, as shown in FIG. in the position where the upstream-side end point Q ₃ opposed, as commutation to the B phase side is completed (see time t3 in FIG. 11), the first switching element 211 in the constant current flip-flop circuit the second switch The switching on and off of the grayed element 221 is adapted to be made.

  As a result, during the transition from the state shown in FIG. 12A to the state shown in FIG. 12B, the protrusion of the rotor unit 31a is caused by the attractive force of the magnetic pole 311 excited by the excitation coil 321 (A-phase excitation coil 32 (A)). The pole 331 is pulled in the direction opposite to the rotation direction, and a braking force against the rotation acts on the rotor unit 31a. In the period of transition from the state shown in FIG. 12B to the state shown in FIG. 12C, the commutation of the excitation current from the A-phase excitation coil 32 (A) to the B-phase excitation coil 32 (B) is performed. In the same way as (see operation during the period of transition from the state shown in FIG. 10B to the state shown in FIG. 10C), the width of the convex pole is larger than the width of the magnetic pole, so that the action of preventing the braking does not occur.

  The ampere turn (magnetomotive force) of each exciting coil will be described with reference to FIG.

The stator unit 31a (31b, 31c, 31d) has a magnetic pole (311 etc.) around which an exciting coil (321 etc.) as an A phase exciting coil 32 (A) is wound, and a B phase exciting coil 32 (B). Every other magnetic pole (312 etc.) around which an exciting coil (322 etc.) is wound is arranged. As shown in FIG. 5, eight magnetic circuits are formed between the in-phase magnetic poles. In FIG. 13, one of the eight magnetic circuits is indicated by a broken line arrow. Each magnetic circuit includes two exciting coils and two gaps g. If the magnetic flux density of the iron core is lower than the saturation region, the magnetic resistance of the iron core can be ignored as compared with the magnetic resistance of the air gap, and it can be considered that the ampere turn of one exciting coil corresponds to one air gap. According to the general theory of electromagnetism, the ampere turn (IN) is
IN (AT) = B · g / μ ₀ ≈B · g × 800,000 (4)
I: Excitation coil current (A)
N: Number of exciting coil turns B: Air gap magnetic flux density (T)
g: gap length (m)
It is represented by

  The upper limit magnetic flux density that does not cause magnetic saturation in a normal iron core (silicon steel plate) is considered to be about 1.6 T. When emphasizing the small size and light weight of the motor, the excitation coil can be designed on the basis of this. However, in the case of a small-capacity motor, the above B can be designed with less than this.

  Further, with reference to FIG. 13, the width of the magnetic pole, the width of the convex pole, and the yoke width will be described.

The width L (arc length) of the convex pole of the rotor unit 33a is
L = 2πR / 8 (number of magnetic poles) (m) (5)
Is set as a reference. However, R is a radius (m) at the end face of the convex pole of the rotor unit 33a.

The magnetic pole width L ′ (arc length) of the stator unit 31a is:
L ′ = KL (6)
Is set as a reference. However, K is the shortening rate in the magnetic pole and is selected based on K <1. The magnetic pole width shortening rate K has an important relationship with the torque pulsation rate and the excitation coil occupation rate, as will be described later.

The width W of the yoke (the thickness of the cylindrical portion of the stator unit) is
W = L '/ 2 (7)
Can be set to This is because 1/2 of the magnetic flux passing through the magnetic pole is divided into the left and right yokes.

  The electromotive force of the exciting coil in the driving state will be described with reference to FIGS. 14A to 14D and FIG.

14A to 14B show the distribution state of the air gap magnetic flux with respect to the angular position in the rotation direction of the convex pole 331 of the rotor unit in the driving state. 14A shows the moment when the rotation direction tip P of the convex pole 311 of the rotor unit is close to the upstream end point Q ₁ of the magnetic pole 311 of the stator unit, and FIG. 14B shows that the same tip P is close to the approximate center point Q _{2 of the} magnetic pole 311. 14C shows the moment when the same tip P approaches the downstream end Q ₃ of the magnetic pole 311, and FIG. 14D shows the moment when the same tip P approaches the upstream end Q ₄ of the magnetic pole 312 adjacent to the rotation direction. . 14A to 14D indicate the magnetic flux generated in the air gap. For simplicity of discussion, assuming that there is no leakage magnetic flux, the air gap magnetic flux density at the portion where the convex pole 331 of the rotor unit and the magnetic pole 311 of the stator unit face each other is a value according to the above-described equation (4). . The part where the magnetic poles of the convex pole 331 do not face each other has an infinite gap length and the gap magnetic flux density is zero.

FIG. 15 is a diagram for explaining the magnetic flux of the excitation magnetic pole of the stator unit and the electromotive force due to the magnetic flux change. FIG. 15A is a diagram depicting changes in magnetic flux in FIGS. 14A to 14D. The horizontal axis represents the rotational angular position, and the angular positions (i), (ii), (iii), and (iv) correspond to the angular positions shown in FIGS. 14A, 14B, 14C, and 14D. ing. When the rotor 31 is rotating at the same angular velocity, the horizontal axis in FIG. 15 may be regarded as the same concept as the time axis. The magnetic flux of the excitation magnetic pole increases linearly in the process of time (ii) (corresponding to FIG. 14B) and time (iii) (corresponding to FIG. 14C), starting from time (i) (corresponding to FIG. 14A). The maximum magnetic flux yam is
Yam = BL'a (Weber) (8)
It becomes. Where B is the magnetic flux density [T] calculated by equation (4), and a is the magnetic pole thickness (m).

When the magnetic flux Ya through the excitation magnetic pole varies with time electromotive force e _a is generated by Faraday's law to the exciting coil. FIG. 15B shows the electromotive force. e _a can be calculated by the following equation (9).
e _a = N · d ya / dt = N · ya m / T (9)
However, N is the number of exciting coil turns, and T is the time [seconds] during the transition from the state shown in FIG. 14A to the state shown in FIG. 14C. The polarity of the electromotive force is positive in the direction that prevents the magnetic flux from increasing, that is, the entrance side of the exciting coil.

As can be seen from FIGS. 14A to 14D, the convex pole 331 of the rotor unit 33 is attracted to the magnetic pole 311 of the stator unit 31 to generate clockwise torque. Since the electromotive force e _a and the excitation current I are constant for the T period, that is, the supplied power is constant for the T period, the generated torque is constant for the T period. FIG. 15C shows torque. [Supply power] = [Mechanical torque output]
e _a × I × T [J] = 2πNτT [J] (10)
The relationship holds. Here, N is the rotational speed per second of the rotor, and τ is the torque [−N · m].

From this, the torque τ is
τ = e _a · I / 2πN [−N · m] (11)
The average electromotive force e _a ′ and the average torque τ ′ considering the magnetic pole shortening rate K are
e _a '= ke _a (12)
τ ′ = kτ (13)
Can be calculated according to

  In FIG. 15, a period between time (iii) and time (iv) is a period during which the A-phase excitation current commutates to the B-phase. The A-phase excitation current gradually decreases, but since the width of the magnetic pole of the stator unit is narrower than the width of the convex pole of the rotor unit, torque due to attractive force does not occur in any direction. During this period, the electromotive force is separated from the main circuit, and no electrical energy is exchanged with the main circuit. Moreover, since the B-phase excitation magnetic poles do not have opposing convex poles, no magnetomotive force is generated between them. At time (iv) in FIG. 15, commutation from the A phase to the B phase is completed, and an operation mainly including the B phase excitation magnetic pole is started.

FIG. 16A to FIG. 16D show the distribution state of the gap magnetic flux with respect to the angular position in the rotation direction of the convex poles of the rotor unit in the regenerative braking state. In FIG. 14A to FIG. 14D described above, the positional relationship between the fixed magnetic poles at the rotation direction tip P of the convex pole 331 of the rotor unit 33 with respect to the points Q ₁ , Q ₂ , Q ₃ , Q ₄ is shown. In FIG. 16A to FIG. 16D, the positional relationship is changed between the rear end P point in the rotation direction of the convex pole 331 and the points Q ₁ , Q ₂ , Q ₃ , and Q _{4 of} the fixed magnetic pole. That is, FIGS. 16A to 16D show states delayed from the rotation direction by the arc length (electrical angle 180 degrees) of the width of the convex pole 331 of the rotor unit 33 as compared with FIGS. 14A to 14D. 17A shows the change in the magnetic flux of the A-phase excitation magnetic pole, FIG. 17B shows the electromotive force of the A-phase excitation coil, and FIG. 17C shows the braking force generated on the convex pole 331 of the rotor unit 33. Represent. The value of the electromotive force e _a, the (9) is the same value as type, the polarity in the direction that prevents the decrease of the flux, the current inlet side of the exciting coil is "negative". The value of the braking force is the same as the driving torque in the equation (11).

Since the switched reluctance motor 30 according to the present embodiment has an 8-pole quadrupole structure as shown in FIGS. 2A and 2B, the electromotive force e _a ′ and torque τ ′ per convex pole described above are Each rotor unit is 4 times, and each quadruple phase is further 4 times, for a total of 16 times. Therefore, the output and torque of the entire motor are
Output = 16 · e _a · I · K (14)
Torque = 16 {e _a · I / 2πN} · K (= output / 2πN) (15)
It becomes.

  With reference to FIGS. 18A to 18C, the supply and regeneration of speed electromotive force and electric energy in the switched reluctance motor drive system according to the present embodiment will be described.

  18A to 18C show energy supply and regeneration operations of the DC constant current power supply device 10 performed in response to the speed electromotive force induced by the rotation of the rotor 33 in the switched reluctance motor 30. FIG. . 18A shows a state where the switched reluctance motor 30 is driven, FIG. 18B shows a state where the switched reluctance motor 30 is regeneratively braked, and FIG. 18C shows a state where the switched reluctance motor 30 stops. Yes.

  In this motor drive system, the product (watt) of electromotive force Ea calculated by Faraday's law or Fleming's law and the current (ampere) flowing at that time can be regarded as net power conversion and reversible power conversion. . The direct current constant current I output from the direct current constant current power supply 10 through the output terminal T1 is fed back to the output terminal T5 through the A phase excitation coil 32 (A) or the B phase excitation coil 32 (B) of the switched reluctance motor 30. To do.

In a state where the switched reluctance motor 30 is driven, a positive electromotive force Ea is generated in the switched reluctance motor 30 as shown in FIG. 18A, and Ea ⁺ × I power (watt) and resistance R The I ² × R power (watt) is supplied from the DC constant current power supply 10 by the current I passing through the A-phase exciting coil 32 (A) or the B-phase exciting coil 32 (B). In this case, Ea ⁺ × I power (watts) is a mechanical output, and I ² R power (watts) is a loss. At the time of braking of the switched reluctance motor 30, as shown in FIG. 18B, a negative electromotive force Ea is generated in the switched reluctance motor 30, and mechanical power is Ea ⁻ × I (watts) and I ² R Converted to electric power. The power of I ² R (watt) becomes a loss, while the power of Ea ⁻ × I (watt) is recovered by the DC constant current power supply device 10 (regeneration). When the switched reluctance motor 30 is in a stopped state, as shown in FIG. 18C, no electromotive force Ea is generated, and the A-phase excitation coil 32 (A) or the B-phase excitation coil 32 (B) Only the I ² R power (watts) corresponding to the loss is supplied from the DC constant current power supply device 10.

  As described above, in the switched reluctance motor drive system according to the present embodiment, a current switching device for driving and regenerative braking (positive / negative speed electromotive force Ea) and rotational speed (speed electromotive force Ea magnitude). With only a phase shift of 180 degrees (electrical angle) of the switching operation at 20, power supply and regeneration are automatically performed without special control.

  Next, with reference to FIGS. 19A to 19D, torque pulsation in the switched reluctance motor 30 according to the embodiment of the present invention having an 8-pole quadruple phase structure will be described.

  FIG. 19A shows four phases (I), (II), (III), and (IV) corresponding to the four stator units 31a to 31d and the rotor units 33a to 33d at the magnetic pole shortening rate K = 0.75. The state of torque and the state of their combined torque are shown. FIG. 19B shows the state of torque or speed electromotive force (during driving) for the four phases (I), (II), (III), and (IV) at the magnetic pole shortening rate K = 0.5 and their combined torque or The state of the combined electromotive force is shown. Thus, when the magnetic pole shortening rate K = 0.75 (see FIG. 19A) and when the magnetic pole shortening rate K = 0.5 (see FIG. 19B), no pulsation appears in the combined torque or the combined electromotive force. I understand that. However, the value of the combined torque and the combined electromotive force is three times the peak value of each phase when K = 0.75, whereas the value of each phase when K = 0.5. It is twice the peak value. Simply, this ratio reduces the motor output. However, the latter has a merit that the space for the exciting coil can be increased as the magnetic pole width becomes smaller.

  FIG. 19C shows a case where the magnetic pole shortening rate K = 0.75 is set by setting the magnetic pole shortening rate K = 0.8 by slightly widening the magnetic pole width based on the magnetic pole shortening rate K = 0.75. The cases where the magnetic pole width is slightly reduced with reference to the magnetic pole shortening rate K = 0.7 are shown. In either case, pulsation occurs in the combined torque and the combined electromotive force. In the switched reluctance motor 30 having an 8-pole quadruple phase (see FIGS. 2A and 2B), assuming a rotational speed of 6000 rpm, a pulsation frequency is 3200 Hz, and a rotational speed is assumed to be 200 rpm (low speed). The pulsation frequency is 107 Hz. The amplitude of pulsation is equal to the torque and electromotive force for one phase (stator unit, rotor unit).

  The vibration and noise of the switched reluctance motor 30 will be described with reference to FIG.

In the switched reluctance motor 30, the magnetic flux density of the iron core is often used at a value close to the saturation region in order to compensate for the weakness in size and weight. Assuming a magnetic flux density of 1.6 T, an attractive force of 102 N is generated per 1 cm ^{2 of the} opposed magnetic pole. FIG. 20 depicts the attractive force acting on the excitation magnetic pole in the 8-pole configuration in the embodiment of the present invention. In this case, the A-phase magnetic pole (the magnetic pole wound with the A-phase excitation coil 32 (A)) is excited, and an equal attractive force from four directions acts on the rotor 33 having a circular outer peripheral core structure. In addition, even when the B-phase magnetic pole is excited, an equal attractive force from four directions acts on the rotor 33. Therefore, since equal attraction forces from four directions always act on the rotor 33, it is considered that vibration and noise are less likely to occur during motor driving.

  According to the switched reluctance motor drive system according to the embodiment of the present invention as described above, each of the four magnetic poles of each of the four stator units 31a to 31d constituting the stator 31 is wound. By switching and supplying a rectangular wave direct current constant current to each of the stator units 31a to 32d at predetermined timings to the A phase exciting coil 32 (A) and the B phase exciting coil 32 (B), The four convex poles of the four rotor units 33a to 33d constituting the rotor 33 arranged on the outside are sequentially attracted to the magnetized magnetic poles of the corresponding stator units 31a to 31d, so that the rotor is Since it rotates, efficient driving with less torque pulsation and vibration becomes possible. Further, a rectangular wave is applied to the A-phase excitation coil 32 (A) and the B-phase excitation coil 32 (B) wound around the four magnetic poles of each of the four stator units 31 a to 31 d constituting the stator 31. The switched reluctance motor 30 can be driven by supplying the DC constant current while alternately switching, and the A-phase excitation coil wound around each magnetic pole of each of the stator units 31a to 31d at the time of braking. The DC constant current power source generates a current corresponding to a change in the facing area of the corresponding rotor units 33a to 33d superimposed on the DC constant current supplied to the 32 (A) and B excitation phase coils 32 (B). Since it can be returned to the apparatus 10, the regenerative electricity can be recovered with the driving of the switched reluctance motor 30.

  The switched reluctance motor 30 according to the present embodiment has an 8-pole quadruple-phase structure, but the number of magnetic poles of the stator units 31a to 31 is 4, 8, 12, 16, 20 ,... Can be selected as an arbitrary number that is a multiple of 4. Further, the number of heavy phases can be selected from any number of 2, 3, 4,...

However, regarding the number of magnetic poles,
(I) When the number of poles is increased, the magnetic pole width for generating the same output can be narrowed and reflected in the iron core yoke, leading to a reduction in the size and weight of the motor.
ii) In the case of the above four poles having the minimum number of poles, the attractive force acts to crush the outer peripheral iron core, causing vibration and noise.

For the number of heavy phases,
(I) When the number of heavy phases is increased, the reactance for one excitation coil phase is reduced in inverse proportion to the square of the number of heavy phases, which is advantageous in terms of commutation overvoltage and high-speed rotation.
(Ii) When the number of heavy phases is increased, the number of current switch units is correspondingly increased, which is disadvantageous for cost and semiconductor loss.
(Iii) When the number of multiple phases is 1, a point where the starting force is zero occurs.
Considering the above points, the number of magnetic poles and the number of multiple phases can be determined.

  The above-described switched reluctance motor drive system collects electric power by rotating the rotating shaft 306 (rotor 33) of the switched reluctance motor 30 by external force (natural force such as wind power or drive force from other engines). It can also be used as a generator system.

  As described above, the switched reluctance motor and its driver system according to the present invention can be efficiently driven, can recover regenerative power, and can reduce torque pulsation and vibration. The rotor having a plurality of convex poles, and a plurality of magnetic poles arranged on the outer periphery of the rotor and having a structure in which an exciting coil is wound around the convex portion, and exciting the plurality of magnetic poles The present invention is useful as a switched reluctance motor configured to rotate the rotor by sequentially supplying a current to the coil and a driving system thereof. Moreover, it can also utilize as what is called an in-wheel motor by fixing a rotor to the wheel of an electric vehicle.

10 DC constant current power supply device 20 Current switching unit 20a, 20b, 20c, 20d Constant current flip-flop circuit 210a, 210b, 210c, 210d First current path 220a, 220b, 220c, 220d Second current path 211a, 211b, 211c, 211d First switching element 221a, 221b, 221c, 221d Second switching element 212a, 212b, 212c, 212d Diode 213a, 213b, 213c, 213d Diode 230a, 230b, 230c, 230d Capacitor 30 Switched reluctance motor 302, 303 Bearing plate 304, 305 Bearing 306 Support shaft 307 Rotor stopper 308 Fixing bolt 309 Angular position detector 31 Stator 31a, 31b, 31c, 31d Stator unit 311, 312, 313, 314, 315, 316, 317, 318 Magnetic pole 32 (A) A phase excitation coil 32 (B) B phase excitation coil 321, 322, 323, 324, 325, 326, 327, 328 Excitation coil 33 Rotor 33a, 33b, 33c, 33d Rotor unit 331, 332, 333, 334 Convex pole

Claims (6)

A stator on which an excitation coil is mounted, and a rotor arranged so as to surround the stator;
The rotor has a plurality of rotor units arranged coaxially;
The stator has a plurality of stator units arranged to face the plurality of rotor units,
Each of the plurality of rotor units has 2n (n is an integer) convex poles arranged at a predetermined angular interval.
Each of the plurality of stator units has 4n (n is an integer) magnetic poles arranged at a predetermined angular interval so that a predetermined gap is formed between each of the convex poles of the corresponding rotor unit. ,
A first exciting coil is wound around every other of the 4n magnetic poles in each of the plurality of stator units, and second magnetic poles are sequentially applied to the magnetic poles other than the wound magnetic poles of the first exciting coil. The exciting coil is wound,
The relative position in the rotational direction of the plurality of rotor units and the plurality of stator units is a switched reluctance motor set so as to deviate by a predetermined angle ;
DC constant current power supply,
A plurality of current switching circuits provided corresponding to each of the plurality of stator units in the switched reluctance motor, for switching between a first current path and a second current path;
Switching control means for controlling the current switching circuit and alternately conducting the first current path and the second,
In a state where the first excitation coil and the second excitation coil provided in the stator unit corresponding to the first current path and the second current path of each current switching circuit are connected in series, respectively, A current switching circuit is connected in series,
A DC constant current output from one output terminal of the DC constant current power supply device is input to the first and second current paths of the first-stage current switching circuit connected in series, and the final-stage current switching circuit. The DC constant current flowing through the first exciting coil connected to the first current path and the second exciting coil connected to the second current path is supplied to the other output terminal of the DC constant current power supply device. The DC constant current power supply device, the plurality of current switching circuits and the switched reluctance motor are connected so as to return,
The switching control means alternately switches the conduction state of the first and second current paths in each of the plurality of current switching circuits according to the angular position of the rotor of the switched reluctance motor, thereby switching a rectangular wave current. Are alternately passed through the first and second exciting coils, and the timing of switching the conduction state of the first and second current paths between when the switched reluctance motor is driven and when braking is applied. A motor drive system that controls each current switching circuit so as to shift by an angle rotation time corresponding to an angle of 180 degrees . The integer n is 2 or more, each of the plurality of rotor units has four or more convex poles, and each of the plurality of stator units has eight or more magnetic poles. The motor drive system described. The relative positions of the plurality of rotor units and the plurality of stator units in the rotation direction are set to be shifted by an angle obtained by dividing the pitch angle of the magnetic poles of the stator unit by the number of the plurality of rotor units. The motor drive system according to claim 1 or 2. The motor drive system according to claim 1, wherein the plurality of rotor units are fixed at the same angular relationship in the rotation direction. The motor drive system according to any one of claims 1 to 3, wherein the plurality of stator units are arranged at the same angular relationship in the rotation direction. The ratio of the width in the rotation direction of each magnetic pole of each of the plurality of stator units to the width in the rotation direction of each convex pole of each of the plurality of rotor units is set to a predetermined ratio of less than one. The motor drive system according to any one of the above.

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