JP2010130823A - Field-winding motor with permanent magnet and motor drive controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To output a rotation phase signal without any delay even if a processing delay of the rotation phase signal occurs in a conversion device. <P>SOLUTION: A field-winding motor with a permanent magnet includes: a shaft 15 which is rotatably supported with respect to end brackets 11, 12; a rotor 25 having a pole core 19 and a field coil 23 which are attached to the shaft 15; and a stator 18 which is fixed to the end brackets 11, 12 and faces the rotor 25. The pole core 19 includes a plurality of claw-shaped magnetic poles 20a, 21a arrayed on the outer peripheral side of the field coil 23 in the rotating direction of the rotator 25 and having alternately different polarities in the rotating direction of the rotor 25. The permanent magnet 31 is disposed between two claw-shaped magnetic poles 20a, 21a adjacent to each other, and a central position of the permanent magnet 31 is located closer to the rotating direction side where the rotor 25 is rotated forward than an intermediate position of a line connecting the central positions of the two claw-shaped magnetic poles 20a, 21a adjacent to each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a field winding type motor with a permanent magnet, and a motor drive control device for driving and controlling a field winding type motor with a permanent magnet.

The motor disclosed in Patent Document 1 is a field winding motor with a permanent magnet (Lundel motor) that increases the magnetic flux generated by a field coil (field current) with a permanent magnet.
In Patent Document 1, in order to detect the magnetic pole position, a magnetic member (detected body) is provided on a part of the rotating body, and a magnetic detection means for detecting the magnetism of the magnetic member at a portion facing the magnetic member. Provided. For example, a Hall element or Hall IC is used as the magnetic detection means. By configuring the magnetic pole position detecting means in this manner, the motor size is increased, and the cost of the resolver and encoder, or the motor itself is suppressed.
JP 2005-192345 A

By the way, in the field winding type motor with a permanent magnet, the position (phase) of the magnetic flux by the field coil increased by the permanent magnet is constant regardless of the motor rotation speed. On the other hand, in a motor drive control device that drives a field winding motor with a permanent magnet, a conversion device (configured by electronic components) that converts a rotation position signal, which is the output of the magnetic pole position detection means, into a rotation phase signal is required. Become. However, when the motor rotates at a high speed and the output (rotational position signal) of the detection means becomes a high frequency, the output cycle is shortened. As a result, the processing of the rotational position signal is delayed in the converter, and the output of the rotational phase signal is delayed with respect to the position of the magnetic flux by the field coil. That is, the output phase delay of the rotation phase signal occurs with respect to the position of the magnetic flux by the field coil. In such a case, the motor performance may be deteriorated, such as a decrease in the output torque of the motor or a deterioration in vibration noise.
An object of the present invention is to prevent an output phase delay of a rotational phase signal with respect to a position of magnetic flux by a field coil even if a processing delay of the rotational position signal occurs in the conversion device.

  In order to solve the above problems, the present invention includes a permanent magnet for supplementing the magnetic flux of the magnetic pole portion, and the position of the total magnetic flux obtained by adding the magnetic flux generated by the magnetic pole portion and the magnetic flux generated by the permanent magnet However, the permanent magnet is arranged so as to be on the side of the rotational direction in which the rotor rotates in the forward direction from the position of the magnetic flux generated by the magnetic pole portion.

  According to the present invention, when field-weakening control is performed to reduce the field current to the field winding as the motor speed increases, the magnetic flux generated by the field winding decreases when the motor speed is high. Therefore, the magnetic flux of the permanent magnet is relatively increased compared with the magnetic flux generated by the field winding. Thereby, in the total magnetic flux, the magnetic flux of the permanent magnet is mainly used, and the position (phase) of the total magnetic flux advances to the rotational direction side where the rotor rotates forward with respect to the position (phase) of the magnetic flux by the field winding. As a result, even if there is a delay in the process of converting the rotational position signal to the rotational phase signal by the phase signal conversion means, the total magnetic flux position, that is, the position of the magnetic pole, is offset by offsetting the advance of the total magnetic flux position and the processing delay. In contrast, the output of the rotation phase signal can be prevented from being delayed.

  Further, when field-weakening control is performed, when the motor speed is low, the field current is large, and the total magnetic flux is mainly the magnetic flux from the field winding. Thereby, the influence of the magnetic flux of the permanent magnet on the total magnetic flux is reduced, and the advance of the position of the total magnetic flux with respect to the position of the magnetic flux by the field winding is reduced. On the other hand, since the motor rotational speed is low, there is almost no delay in the process of converting the rotational position signal into the rotational phase signal. As a result, it is possible to prevent the output of the rotational phase signal from being delayed with respect to the position of the total magnetic flux even when the motor rotational speed is low.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
(Constitution)
The present embodiment is a motor drive control device.
1 and 2 show a motor drive control device. As shown in FIGS. 1 and 2, the motor drive control device includes a motor 10 and a drive control unit 50 that drives the motor 10. The drive control unit 50 includes a motor controller 60 and an inverter 70. FIG. 2 is a specific example of the motor drive control device shown in FIG.

  FIG. 3 shows a detailed configuration of the motor 10. The motor 10 is a field winding motor with a permanent magnet (Lundel motor). In FIG. 3, reference numerals 11 and 12 denote a pair of end brackets that constitute the housing of the motor 10. In FIG. 3, the left end bracket (hereinafter, referred to as a first end bracket) 11 has a bottomed shallow bowl shape. Further, the right end bracket (hereinafter referred to as a second end bracket) 12 in FIG. 3 has a deep saddle shape with a bottom. The end brackets 11 and 12 are made of, for example, aluminum.

Cylindrical bearing boxes 11a and 12a are formed at the center of the side surfaces of the end brackets 11 and 12 (portion corresponding to the bottom of the bowl-shaped member). Bearings 13 and 14 are fixed in the bearing boxes 11a and 12a. The bearings 13 and 14 rotatably support a shaft 15 extending in a direction opposite to the end brackets 11 and 12.
A stator 18 is provided on the inner surface of the end brackets 11 and 12. The stator 18 includes a stator core 16 and a stator coil 17. The stator core 16 is a substantially cylindrical iron core formed by laminating a plurality of annular magnetic members. The stator coil 17 is inserted into a plurality of slots formed in the inner peripheral portion of the stator core 16 and is constituted by a three-phase star connection.

  A pole core 19 is fixed to the shaft 15. A pole core 19 is attached to the portion of the shaft 15 that faces the inner peripheral side of the stator core 16. At this time, the pole core 19 is attached so as to face the stator core 16 with a gap. The pole core 19 is composed of a pair of cores 20 and 21. A pair of cores 20 and 21 are arranged facing each other in the axial direction of the shaft 15. Each of the cores 20 and 21 has a plurality of claw-shaped magnetic pole portions (hereinafter referred to as claw-shaped magnetic pole portions) 20a and 21a in the circumferential direction (circumferential direction of the shaft 15) on the outer periphery.

FIG. 4 is a front view showing a configuration including the pole core 19 and the shaft 15. FIG. 5 is a side view of the pole core 19. As shown in FIGS. 4 and 5, the claw-shaped magnetic pole portions 20 a and 21 a extend from the outer peripheral portion of one core 20 (or 21) toward the other core 21 (or 20) facing (extend in the axial direction). ). The claw-shaped magnetic pole portions 20a and 21a are arranged such that the claw-shaped magnetic pole portions 20a of one core 20 and the claw-shaped magnetic pole portions 21a of the other core 21 are alternately meshed in the circumferential direction. That is, the pair of cores 20 and 21 face each other so that the respective claw-shaped magnetic pole portions 20a and 21a mesh with each other. By supplying a field current to a field coil 23 described later, the pole core 19 becomes an electromagnet, and the claw-shaped magnetic pole portions 20a and 21a alternately constitute N-pole and S-pole magnetic poles in the circumferential direction.
Further, permanent magnets (interpole magnets) are attached to the claw-shaped magnetic pole portions 20a and 21a. By attaching permanent magnets to the claw-shaped magnetic pole portions 20a and 21a, the magnetic flux (field magnetic flux) of the claw-shaped magnetic pole portions 20a and 21a by the field coil 23 is compensated to increase the magnetic flux.

  FIGS. 6-8 shows the attachment structure of the permanent magnet 31. FIG. FIG. 6 is a front view. FIG. 7 is a perspective view. FIG. 8 is an assembled perspective view. As shown in FIGS. 6-8, the permanent magnet 31 is each attached to the both ends in the circumferential direction of the claw-shaped magnetic pole part 20a (or 21a). Or the permanent magnet 31 is attached between the adjacent claw-shaped magnetic pole part 20a and the claw-shaped magnetic pole part 21a. Specifically, on the advance side (rotation direction side, advance side) of the rotation direction of the pole core 19 (rotor 25) with respect to the position of the claw-shaped magnetic pole portions 20a, 21a (position or phase of A in FIG. 6). The permanent magnets 31 are shifted and arranged. That is, the intermediate position O of the line connecting the center of gravity BO (the position or phase of B in FIG. 6 in the rotational direction) of each of the two permanent magnets 31 is the claw-shaped magnetic pole portion 20a ( Or 21a) is shifted (offset) to the rotational direction side with respect to the center line (line perpendicular to the rotational direction (position or phase of A in FIG. 6)).

  Here, by applying a field current to the field coil 23, the position (phase) of the magnetic flux generated by the claw-shaped magnetic pole portions 20a, 21a is generated in accordance with the shape of the claw-shaped magnetic pole portions 20a, 21a. Therefore, the position of the magnetic flux generated by the claw-shaped magnetic pole portions 20a, 21a coincides with the center (center of gravity) of the shape of the claw-shaped magnetic pole portions 20a, 21a. On the other hand, the position (phase) of the magnetic flux generated by the permanent magnet 31 is also generated in accordance with the shape of the permanent magnet 31. The position of the magnetic flux generated by the permanent magnet 31 coincides with the center (center of gravity) of the shape of the permanent magnet 31. Therefore, since the permanent magnet 31 is shifted from the center line of the claw-shaped magnetic pole portion 20a (or 21a) located on both sides thereof in the rotational direction, the total magnetic flux is claw-shaped magnetic pole portions 20a, 21a. The position is shifted to the advance side in the rotation direction of the pole core 19 with respect to the position of. The total magnetic flux is a magnetic flux obtained by adding the magnetic flux generated by the permanent magnet 31 to the magnetic flux generated by the claw-shaped magnetic pole portions 20a and 21a.

FIG. 9 shows a comparison structure (contrast structure) for explaining the structure of the pole core 19 of the present embodiment shown in FIGS.
In the structure of the pole core 19 in FIG. 9, the intermediate position O of the line connecting the center of gravity CO (the position of C in FIG. 9 in the rotation direction) of each of the two permanent magnets 31 is the claw where the permanent magnets 31 are located on both sides This coincides with the center line (position or phase of A in FIG. 9) of the magnetic pole portion 20a (or 21a). That is, the two permanent magnets 31 are arranged at positions symmetrical with respect to the center line of the claw-shaped magnetic pole portions 20a and 21a. In this case, the position of the magnetic flux of the permanent magnet 31 coincides with the position of the claw-shaped magnetic pole portions 20 a and 21 a in the rotation direction of the pole core 19.

  As shown in FIG. 8, the bobbin 28 is fixed to the shaft 15 while being sandwiched between the two cores 20 and 21 forming the pole core 19. A field coil 23 is wound around the bobbin 28. At this time, the field coil 23 is concentric with the shaft 15. As a result, as shown in FIG. 3, the field coil 23 is disposed at a position facing the inner peripheral surfaces of the claw-shaped magnetic pole portions 20 a and 21 a of the pole core 19. In addition, the bobbin 28 is subjected to insulation treatment.

As shown in FIG. 3, both ends of the shaft 15 protrude outward from the outer surfaces of the end brackets 11 and 12. And as shown also in FIG. 4, the part which protruded from the 2nd end bracket 12 in the shaft 15 is a reduced diameter shape.
A slip ring 24 is fixed to one end of the shaft 15. A slip ring 24 is electrically connected to the field coil 23 via a lead wire. The slip ring 24 extends to the outside of the outer surface of the second end bracket 12 along the shaft 15. The slip ring 24 is fixed on the shaft 15 by a resin mold. Further, for example, a pulley is fixed to the other end of the shaft 15. Here, the shaft 15, the pole core 19, the field coil 23 (bobbin 28), and the slip ring 24 constitute a rotor 25.

  A brush 26 is disposed at a position facing the outer surface of the second end bracket 12. The brush 26 is in sliding contact with the slip ring 24 and supplies power to the slip ring 24. The motor controller 60 controls the field current flowing through the field coil 23. At this time, a field current for exciting the field coil 23 is supplied from the brush 26 to the slip ring 24 and then supplied to the field coil 23 via a lead wire. Thereby, the motor controller 60 controls the rotation of the motor 10.

Further, as shown in FIG. 2, the motor controller 60 measures the current value and voltage value of the energized portion to the field coil 23. The current value measurement is for controlling the field current. The voltage value measurement is for detecting an abnormality (short circuit, overvoltage, etc.).
As shown in FIGS. 2 and 3, a rotation sensor 27 is attached to the end portion of the shaft 15 so as to be disposed outside the end brackets 11 and 12 forming the housing. In the synchronous motor, the timing of energizing the armature (stator coil 17) must be aligned with the position of the rotor 25. Therefore, a rotation sensor 27 is provided for detecting the rotation position (rotation angle) of the rotor 25. The rotation sensor 27 is a resolver or an encoder. As shown in FIG. 2, the rotation sensor 27 outputs the detected signal (rotational position signal, resolver signal) to the motor controller 60.
The motor controller 60 generates an inverter drive signal (inverter control signal) based on the detection signal (rotational position signal, resolver signal) from the rotation sensor 27. At this time, the motor controller 60 converts the detection signal from the rotation sensor 27 into a rotation phase signal.

FIG. 10 shows a configuration in which the rotation position signal (detection signal, resolver signal) from the rotation sensor 27 is converted into a rotation phase signal in the motor controller 60. As shown in FIG. 10, the motor controller 60 includes an input gain filter 61 and a conversion IC (R / D IC) 62 serving as an I / F circuit. Thereby, the motor controller 60 converts the rotation position signal from the rotation sensor 27 via the input gain filter 61 and the conversion IC (R / D IC) 62 and outputs it as a rotation phase signal (resolver output). . For example, the motor controller 60 is an ECU (Electronic Control Unit).
The motor controller 60 generates a drive signal (inverter control signal) for the inverter 70 from the rotational phase signal obtained by the conversion.

  As shown in FIG. 2, the inverter 70 includes six switching elements (for example, MOS-FETs and IGBTs) 71. Specifically, it is divided into three sets of upper and lower arm switching elements 71 corresponding to the three phases of the stator coil 17 of the motor 10. The inverter 70 controls the switching of each of the three sets of switching elements 71 based on the drive signal (inverter control signal) obtained from the rotational phase signal, and supplies the three-phase alternating current to the stator coil 17. At this time, the three switching elements 71 are controlled to be switched at a predetermined timing in synchronization with the rotation of the rotor 25 by a drive signal (inverter control signal), and three-phase alternating current is supplied to the stator coil 17. As a result, an armature current flows through the stator coil 17.

Further, the inverter 70 includes a current sensor 72 and a voltage sensor 73 for controlling the inverter. The current sensor 72 and the voltage sensor 73 output detection signals to the motor controller 60. Based on the current detection signal from the current sensor 72, the motor controller 60 performs vector control to control the motor torque and the rotational speed by feeding back current. The motor controller 60 monitors the voltage from the generator 81 based on the voltage detection signal from the voltage sensor 73. Thereby, the motor controller 60 imposes a restriction on the motor drive.
In addition, the electric power of the auxiliary battery 82 can be supplied to the field coil 23 of the motor 10. Further, the electric power converted by the inverter 70 can be supplied to the field coil 23 of the motor 10. Further, the temperature of the motor 10 (for example, the stator 18) can be monitored by the thermistor 83.

(Operation and action)
By causing a field current to flow through the field coil 23, the pole core 19 functions as an electromagnet, and the claw-shaped magnetic pole portions 20a and 21a generate a magnetic field. Thus, the motor 10 (rotor 25) rotates by the interaction between the magnetic field generated by the claw-shaped magnetic pole portions 20a and 21a and the magnetic field generated by the stator coil 17.
At this time, the motor controller 60 causes the maximum amount of field current to flow through the field coil 23 as motor control at the time of low motor rotation. At this time, the magnetic flux by the field coil 23 becomes the main magnetic flux, and the magnetic flux (magnet magnetic flux) of the permanent magnet 31 becomes the auxiliary magnetic flux. Here, the magnetic flux generated by the field coil 23 is a magnetic flux generated by flowing a field current through the field coil 23 or a magnetic flux generated by the claw-shaped magnetic pole portions 20a and 21a. The magnetic flux generated by the field coil 23 changes according to the magnitude of the field current. By such motor control during low rotation, the magnetic flux (field magnetic flux) generated by the field coil 23 is increased, and the motor 10 generates a large torque.

  Furthermore, when the motor speed increases, the motor controller 60 performs field weakening control as the motor control. The field weakening control is control that extends the operating range by reducing the induced voltage generated by the motor when the motor is driven. Field weakening control is field control frequently used in motor control. As field weakening control, the amount of field current supplied to the field coil 23 is reduced as the motor speed increases.

FIG. 11 shows the relationship between the motor speed and field current during field weakening control. As shown in FIG. 11, when the motor speed increases, the field current is decreased by having a linear relationship with the increase in motor speed.
This field weakening control increases the field current flowing through the field coil 23 when the motor speed is low. Thereby, since the magnetic flux of the permanent magnet 31 is constant, the magnetic flux (field magnetic flux) by the field coil 23 becomes dominant. At this time, the position (phase) of the total magnetic flux is close to the position (phase) of the magnetic flux by the field coil 23 or the position (phase) of the claw-shaped magnetic pole portions 20a and 21a. That is, as described above, the permanent magnets 31 are arranged so as to be shifted in the rotational direction with respect to the center line of the claw-shaped magnetic pole portions 20a (or 21a) located on both sides thereof, so that the position of the total magnetic flux is set to the field The pole 23 is shifted to the advance side in the rotation direction of the magnetic flux by the coil 23. On the other hand, as a result of the magnetic flux by the field coil 23 becoming dominant, the position of the total magnetic flux is close to the position of the magnetic flux by the field coil 23.

  In this field weakening control, when the motor speed is increased, the field current flowing through the field coil 23 is reduced (minimized). Thereby, the magnetic flux by the field coil 23 becomes small. As a result, although the magnetic flux of the permanent magnet 31 is constant, the magnetic flux of the permanent magnet 31 is relatively large in comparison with the magnetic flux generated by the field coil 23. Thereby, the magnetic flux of the permanent magnet 31 becomes main or becomes dominant. As a result, the position of the total magnetic flux is close to the position (phase) of the magnetic flux of the permanent magnet 31 on the advance side.

As described above, the position of the total magnetic flux is changed by changing the magnitude of the field current in accordance with the motor rotation speed. At this time, by changing the field current linearly with respect to the motor rotational speed, the advance angle changes linearly according to the motor rotational speed. The advance angle here is an angle toward the advance angle side.
FIG. 12 visually shows the change in the magnitude of the magnetic flux (field magnetic flux) by the field coil 23 with respect to the change in the field current (motor rotation speed). As shown in the change from FIG. 12A to FIG. 12B, when the field current increases (when the motor rotation speed decreases), the magnetic flux (field magnetic flux) by the field coil 23 increases. Further, as shown in FIGS. 12A and 12B, the magnetic flux (magnet magnetic flux) of the permanent magnet 31 is constant regardless of the field current (motor rotation speed). For this reason, the total magnetic flux increases as the field current increases.

By the way, as described above, the motor controller 60 converts the rotational position signal (resolver signal) into the rotational phase signal (resolver output).
Here, the position signal (resolver signal) input to the motor controller 60 (such as the conversion IC 62) has a low frequency when the motor rotation speed is low, and therefore, one cycle time is long. Here, one cycle represents an electrical angle (rotating electrical angle). The electrical angle is determined by the number of magnetic poles in the rotor, where one rotation of the rotor is a mechanical angle of 360 degrees. For example, in the case of 6 pole pairs (6 pairs of N poles and S poles), the mechanical angle is 60 degrees and the electrical angle is 360 degrees. One cycle represents this electrical angle of 360 degrees, and the time (cycle) becomes shorter as the motor rotation speed increases. Therefore, when the motor rotational speed is low, the time of one cycle of the rotational position signal input to the motor controller 60 becomes longer, and when the motor rotational speed is high, the time of one cycle of the rotational position signal input to the motor controller 60. Becomes shorter.

  On the other hand, the motor controller 60 (the conversion IC 62 or the like) performs processing for a certain processing time (processing time is determined). For example, since the input gain filter 61 constituting the motor controller 60 is a filter constant, and the conversion IC 62 is a conversion processing time (R / D processing time), the gain filter 61 and the conversion IC 62 perform processing in a fixed processing time. ing. The processing time of the motor controller 60 is constant regardless of the motor speed. Therefore, when the motor rotation speed is low, the time of one cycle of the rotation position signal (detection signal of the rotation sensor 27) becomes longer (because the frequency becomes lower). The time spent for processing (the relative proportion of processing time) is shortened. In this case, the processing delay time of the motor controller 60 is at a negligible level. However, when the motor rotational speed is high, the time of one cycle of the rotational position signal is shortened (because the frequency is high), so the time that the motor controller 60 spends on processing for the rotational position signal (processing time and Relative ratio) is longer. As a result, the processing delay time of the motor controller 60 becomes longer than when the motor rotation speed is low.

From the above, since the processing time of the motor controller 60 is constant, the processing delay time for the rotational position signal becomes longer as the motor rotational speed becomes higher. Specifically, the processing delay of the rotational position signal (processing delay such as conversion processing) changes in a linear manner according to the motor speed. When such a processing delay of the rotational position signal occurs, an output delay of the rotational phase signal obtained from the rotational position signal occurs.
As described above, by changing the magnitude of the field current in a linear form according to the motor rotational speed, the position of the total magnetic flux is changed on the advance side in the primary linear form in accordance with the motor rotational speed. . On the other hand, the processing delay of the rotational position signal changes linearly according to the motor speed.

  FIG. 13 shows a processing delay of the rotational position signal according to the motor rotational speed (also referred to as a processing delay of the rotational phase signal) (FIG. 13A), magnetic flux advance angle (advance angle of total magnetic flux phase) (FIG. 13 ( B)) and the output phase delay of the rotational phase signal (FIG. 13C). As shown in FIG. 13 (A), when the motor speed increases, the processing delay of the rotational position signal increases in a linear form. On the other hand, as shown in FIG. 13B, when the motor speed increases, the magnetic flux advance angle increases in a linear form. As a result, as shown in FIG. 13C, the processing delay of the rotational position signal and the magnetic flux advance angle are offset, and the phase of the magnetic flux (total magnetic flux), that is, the output phase delay of the rotational phase signal with respect to the magnetic pole is zero. become.

FIG. 14 shows the relationship with control delay and the like when viewed from the induced voltage. As shown in FIG. 14, the control delay (rotation position signal processing delay) increases as the motor speed increases. In addition, the field current is reduced by the field weakening control as the motor rotation speed increases. Therefore, the induced voltage (or field magnetic flux) by the field coil 23 becomes small. On the other hand, the induced voltage (or magnet magnetic flux) by the permanent magnet 31 becomes (relatively) large. As a result, as the motor rotational speed increases, the total induced voltage (or total magnetic flux) value obtained by adding the induced voltage by the field coil 23 and the induced voltage by the permanent magnet 31 decreases, but the phase of the total induced voltage is The phase proceeds to the phase of the induced voltage by the permanent magnet 31 (approaches the phase of the induced voltage by the permanent magnet 31).
Thus, the control delay increases as the motor speed increases. On the other hand, when the motor rotation speed increases, the phase of the total induced voltage advances toward the phase of the induced voltage by the permanent magnet 31. As a result, the control delay and the advance of the phase of the induced voltage are canceled out, and the rotation phase signal can be output with the delay with respect to the induced voltage change being zero.

  FIG. 15 shows the relationship between the induced voltage and the rotational phase signal (resolver output). As shown in FIG. 15A, when the motor rotation speed is high and the field current is small (same conditions as in FIG. 12A), the induced voltage by the field coil 23 becomes small, so that the total induced voltage (or The total magnetic flux) becomes smaller. On the other hand, as shown in FIG. 15B, when the motor speed is low and the field current is large (same conditions as in FIG. 12B), the induced voltage (or field magnetic flux) by the field coil 23 increases. Therefore, the total induced voltage is increased. Thus, although the total induced voltage changes in accordance with the field current, as shown in FIGS. 15A and 15B, the rotational phase signal does not depend on the field current, that is, regardless of the motor rotational speed. The phase change of (resolver output) and the phase change of the total induced voltage are matched (synchronized).

  Here, a case where the motor 10 rotates in reverse is considered. As described above, the permanent magnet 31 is arranged so as to be on the advance side with respect to the rotation direction (one direction, forward rotation direction). Therefore, when the motor 10 rotates in the reverse direction, the permanent magnet 31 is positioned on the retard side (the side opposite to the advance side) with respect to the rotation direction. However, if the motor 10 is for driving a vehicle, the reverse rotation of the motor 10 is in the vehicle reverse direction. Usually, in the backward direction, the control is performed so that the motor rotation speed is not greatly increased. Therefore, since the scene where the field weakening control is not performed, the field current does not flow (the field current is not reduced). Thus, the magnetic flux of permanent magnet 31 does not become dominant because field current does not become small. As a result, even if the position of the permanent magnet 31 is retarded during the reverse rotation of the motor 10, the effect hardly appears in the performance of the motor. In addition, when the motor is running at a low speed where field-weakening control is not performed, the field current is large and the magnetic flux of the field coil 23 is dominant. Does not occur.

(Modification of the embodiment)
(1) In this embodiment, the field current flowing through the field coil 23 is controlled as field weakening control. On the other hand, as the field weakening control, the armature current (current to the three-phase stator coil 17) can also be controlled and implemented. In this case, the current phase of the armature current is made to flow in the direction to cancel the magnetic flux of the magnetic pole portion, and the amount of the current is variably controlled.
(2) The intermediate position O of the line connecting the center of gravity BO of each of the two permanent magnets 31 (the position B in FIG. 6 in the rotation direction) is the claw-shaped magnetic pole portion 20a (or the permanent magnet 31 is located on both sides). The shape and arrangement of the permanent magnets 31 can be changed as long as they deviate in the rotational direction with respect to the center line 21a) (position A in FIG. 6).

(3) FIG. 16 shows another shape of the permanent magnet 31. As shown in FIG. 16, the permanent magnet 31 attached to the claw-shaped magnetic pole part 20a (or 21a) on the rotation direction side is formed into a shape extending to the base side of the claw-shaped magnetic pole part 20a (or 21a). Further, the permanent magnet 31 attached to the claw-shaped magnetic pole part 20a (or 21a) on the opposite side (reverse direction side) to the rotation direction side extends to the end side of the claw-shaped magnetic pole part 20a (or 21a). To. For example, as shown in FIG. 9, the middle position of the line connecting the centroids CO of the two permanent magnets 31 coincides with the center line (position A in FIG. 16) of the claw-shaped magnetic pole portion 20a (or 21a). The permanent magnet 31 is elongated on the base side or the tip side as described above. As a result, the intermediate position O of the line connecting the center of gravity DO (the position of D in FIG. 16 in the rotation direction) of each of the two permanent magnets 31 is the claw-shaped magnetic pole portion 20a (or the position where the permanent magnets 31 are located on both sides). 21a) is shifted to the rotational direction side with respect to the center line (position A in FIG. 13).

(4) FIGS. 17 and 18 show still another shape of the permanent magnet 31. As shown in FIG.17 and FIG.18, the permanent magnet 31 is arrange | positioned on the surface of the nail | claw-shaped magnetic pole part 20a (or 21a). The surface of the claw-shaped magnetic pole part 20a (or 21a) here is a side surface in the radial direction of the rotor 25 in the claw-shaped magnetic pole part 20a (or 21a). Then, the permanent magnet 31 has its center position E (center position in the rotation direction) shifted to the rotation direction side with respect to the center line (position A in FIG. 17) of the claw-shaped magnetic pole part 20a (or 21a). Deploy. In this case, the permanent magnet 31 may be left between the adjacent claw-shaped magnetic pole portions 20a and 21a (between the magnetic poles) (see FIGS. 6 and 16). Further, instead of the permanent magnet 31 between the adjacent claw-shaped magnetic pole portions 20a and 21a (between the magnetic poles), as shown in FIGS. 17 and 18, the permanent magnet 31 is placed on the surface of the claw-shaped magnetic pole portion 20a (or 21a). To place.

(5) At least one permanent magnet 31 among the plurality of permanent magnets 31 included in the motor 10 can be arranged such that the phase of the total magnetic flux is on the advance side.
In the present embodiment, the shaft 15 realizes a rotating shaft that is rotatably supported with respect to the housing. Moreover, the rotor 25 implement | achieves the rotor which has the iron core (pole core 19) and field winding (field coil 23) attached to the said rotating shaft. Further, the stator 18 is fixed to the casing and realizes a stator facing the rotor. Further, the claw-shaped magnetic pole portions 20a, 21a are arranged in the rotation direction of the rotor on the outer peripheral side of the field winding, and realize a plurality of magnetic pole portions having different polarities alternately in the rotation direction of the rotor. is doing.

And in this embodiment, while providing the permanent magnet for supplementing the magnetic flux of the said magnetic pole part, the position of the total magnetic flux which added the magnetic flux which the said magnetic pole part generate | occur | produced, and the magnetic flux which the said permanent magnet generates is this magnetic pole It is realized that the permanent magnet is arranged so as to be closer to the rotation direction in which the rotor rotates forward than the position of the magnetic flux generated by the portion.
Specifically, the permanent magnet is arranged between two adjacent magnetic pole portions, and the center position of the permanent magnet is rotated more than the intermediate position of a line connecting the center positions of the two adjacent magnetic pole portions. It is realized that the child is on the side of the rotation direction in which the child rotates normally (see FIGS. 6 and 16).

Further, the permanent magnet is disposed on a side surface in the radial direction of the rotor in the magnetic pole portion, and the rotation axis of the permanent magnet rotates more forward than the center position of the magnetic pole portion provided with the permanent magnet. It has realized that it exists in the rotation direction side (refer said FIG. 17, FIG. 18).
In the present embodiment, the rotation sensor 27 realizes a rotation position detection unit that detects the rotation position of the rotor. The motor controller 60 (particularly, the input gain filter 61 and the conversion IC (R / D IC) 62) realizes phase signal conversion means for converting the rotational position detected by the rotational position detection means into a rotational phase signal. . Further, the inverter 70 realizes an inverter that controls switching of elements based on the rotational phase signal obtained by the conversion by the phase signal conversion means and flows an armature current to the stator. Further, the motor controller 60 realizes a field current control means for causing a field current to flow through the field winding, and the field current to the field winding is increased as the number of rotations of the rotor increases. Realizing field-weakening control to make it smaller.

(effect)
The effect in this embodiment is as follows.
(1) In the field winding type motor with a permanent magnet, a permanent magnet for supplementing the magnetic flux of the claw-shaped magnetic pole portions 20a, 21a (field coil 23) is provided, and the magnetic flux generated by the field coil 23 and the permanent magnet 31 are The permanent magnet 31 is arranged so that the position of the total magnetic flux obtained by adding the generated magnetic flux is closer to the rotation direction in which the rotor 25 rotates forward than the position of the magnetic flux by the field coil 23.

  Thus, when field weakening control is performed to reduce the field current to the field coil 23 as the motor speed increases, the magnetic flux generated by the field coil 23 decreases when the motor speed is high. Therefore, the magnetic flux of the permanent magnet 31 becomes relatively large as compared with the magnetic flux generated by the field coil 23. Thereby, in the total magnetic flux, the magnetic flux of the permanent magnet 31 is mainly used, and the position (phase) of the total magnetic flux advances to the rotational direction side where the rotor 23 rotates forward with respect to the position (phase) of the magnetic flux by the field coil 23. . As a result, even if there is a delay in the process of converting the rotational position signal to the rotational phase signal by the motor controller 60 (phase signal conversion means), the position of the total magnetic flux is offset by the advance of the total magnetic flux position and the processing delay. That is, it is possible to prevent the output of the rotation phase signal from being delayed with respect to the position of the claw-shaped magnetic pole portions 20a and 21a.

Further, when field-weakening control is performed, when the motor speed is low, the field current is large, so that the magnetic flux by the field coil 23 is mainly used in the total magnetic flux. Thereby, the influence of the magnetic flux of the permanent magnet 31 on the total magnetic flux is reduced, and the advance of the position of the total magnetic flux with respect to the position of the magnetic flux by the field coil 23 is reduced. On the other hand, since the motor rotational speed is low, there is almost no delay in the process of converting the rotational position signal into the rotational phase signal. As a result, it is possible to prevent the output of the rotational phase signal from being delayed with respect to the position of the total magnetic flux even when the motor rotational speed is low.
Thereby, it can prevent that performance deteriorates, such as a fall of the output torque of a motor, and the deterioration of a vibration sound.

(2) The permanent magnet 31 is disposed between the two adjacent claw-shaped magnetic pole portions 20a and 21a. At this time, the center position of the permanent magnet 31 is closer to the rotation direction in which the rotor 25 rotates forward than the intermediate position of the line connecting the center positions of the two adjacent claw-shaped magnetic pole portions 20a and 21a.
As a result, the position of the total magnetic flux obtained by adding the magnetic flux generated by the field coil 23 and the magnetic flux generated by the permanent magnet 31 is closer to the rotational direction where the rotor 25 rotates forward than the position of the magnetic flux generated by the field coil 23. Thus, the structure which arrange | positions this permanent magnet 31 is easily realizable.

(3) The permanent magnet 31 is arranged on the side surface in the radial direction of the rotor 25 in the claw-shaped magnetic pole portions 20a and 21a. At this time, the center position of the permanent magnet 31 is on the rotation direction side where the rotation axis rotates forward with respect to the center position of the claw-shaped magnetic pole portions 20a, 21a provided with the permanent magnet 31.
As a result, the position of the total magnetic flux obtained by adding the magnetic flux generated by the field coil 23 and the magnetic flux generated by the permanent magnet 31 is closer to the rotational direction where the rotor 25 rotates forward than the position of the magnetic flux generated by the field coil 23. Thus, the structure which arrange | positions this permanent magnet 31 is easily realizable.

(4) In the field weakening control, the field current is changed linearly according to the motor rotation speed.
As the motor increases from low rotation to high rotation, the advance of the total magnetic flux phase increases continuously. On the other hand, the field current can be reduced as the motor rotational speed increases, and the processing delay for converting the rotational position signal into the rotational phase signal and the advance of the phase of the total magnetic flux can be offset appropriately. Thereby, there is an effect that it is possible to prevent the output of the rotation phase signal from being delayed over the entire rotation speed of the motor.

(5) Unlike patent document 1, since magnetic detection means, such as a Hall element and Hall IC, are not provided, the problem resulting from the fall of magnetic pole position detection accuracy does not generate | occur | produce. For example, if the magnetic detection accuracy, that is, the magnetic pole position detection accuracy is low, high-grade motor drive control such as vector control that is often employed in vehicle drive motors cannot be performed, resulting in reduced torque and vibration noise. However, since this embodiment does not have such a magnetic detection means, such a problem does not occur.
Further, in Patent Document 1, since the detected object and the magnetic detection means are arranged inside the motor as the magnetic pole position detection means, the magnetic pole position adjustment function at the time of assembly is not structurally provided, or the magnetic pole position adjustment at the time of assembly is performed. Is difficult. If the magnetic pole position adjustment is not accurate, the position accuracy is deteriorated, resulting in deterioration of torque and vibration noise. However, in the present embodiment, such a problem does not occur because the structure does not have such a magnetic pole detection means.

It is a block diagram which shows the structure of the motor drive control apparatus of embodiment of this invention. It is a figure which shows the specific example of a motor drive control apparatus. It is a figure which shows the structure of a motor. It is a front view which shows the structure which consists of the pole core and shaft in a motor. It is a side view of the pole core in a motor. It is a front view which shows the attachment structure of a permanent magnet. It is a perspective view which shows the attachment structure of a permanent magnet. It is an assembly perspective view shown with a pole core, a bobbin, a permanent magnet, and the like. It is a front view which shows the comparison of the attachment structure of a permanent magnet. It is a block diagram which shows the structure which converts the detection signal (resolver signal) from a rotation sensor into a rotation phase signal in a motor controller. It is a characteristic view which shows the relationship between the motor rotation speed and field current in field-weakening control. It is a figure which shows visually the change of the magnitude | size of the magnetic flux (field magnetic flux) by a field coil with respect to the change of a field current (motor rotation speed). It is a figure which shows the relationship between the processing delay ((A)) of the rotational position signal (or rotational phase signal), the magnetic flux advance angle ((B)), and the output phase delay ((C)) of the rotational phase signal with respect to the motor rotational speed. is there. It is a figure which shows the relationship with the control delay etc. at the time of seeing with an induced voltage. It is a characteristic view which shows the relationship between an induced voltage and a rotation phase signal (resolver output). It is a front view which shows the other attachment structure of a permanent magnet. It is a front view which shows other attachment structure of a permanent magnet. It is a side view which shows other attachment structure of a permanent magnet.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Motor, 15 Shaft, 16 Stator core, 17 Stator coil, 18 Stator, 19 Pole core, 20a, 21a Claw-shaped magnetic pole part, 23 Field coil, 25 Rotor, 31 Permanent magnet 60 Motor controller, 70 Inverter

Claims (5)

A rotor having a rotating shaft rotatably supported with respect to the housing, and an iron core and a field winding attached to the rotating shaft;
A stator fixed to the housing and facing the rotor,
The iron core includes a plurality of magnetic pole portions arranged in the rotation direction of the rotor on the outer peripheral side of the field winding, and having different polarities alternately in the rotation direction of the rotor,
The position of the total magnetic flux that includes a permanent magnet for supplementing the magnetic flux of the magnetic pole portion and that is the sum of the magnetic flux generated by the magnetic pole portion and the magnetic flux generated by the permanent magnet is the position of the magnetic flux generated by the magnetic pole portion. A field winding motor with a permanent magnet, wherein the permanent magnet is arranged so as to be closer to the rotational direction in which the rotor rotates forward.   The permanent magnet is disposed between two adjacent magnetic pole portions, and the rotor is rotated forward from a center position of a line connecting the central positions of the two adjacent magnetic pole portions. The field winding type motor with a permanent magnet according to claim 1, wherein the field winding type motor is on a rotating direction side.   A permanent magnet is arranged on the radial side surface of the rotor in the magnetic pole part, and the center position of the permanent magnet is in the direction of rotation in which the rotation shaft rotates forward relative to the center position of the magnetic pole part provided with the permanent magnet. The field winding type motor with a permanent magnet according to claim 1. In the motor drive control device which drives and controls the field winding type motor with a permanent magnet according to any one of claims 1 to 3,
Rotational position detecting means for detecting the rotational position of the rotor;
Phase signal converting means for converting the rotational position detected by the rotational position detecting means into a rotational phase signal;
An inverter that controls switching of the element based on the rotational phase signal obtained by the phase signal conversion means, and that causes an armature current to flow through the stator;
Field current control means for causing a field current to flow through the field winding, and
The motor drive control device according to claim 1, wherein the field current control means performs field-weakening control for reducing the field current to the field winding as the rotational speed of the rotor increases.   5. The motor drive control device according to claim 4, wherein the control unit changes the field current linearly in accordance with the number of rotations of the rotor.

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