Motor control device, motor module, and motor control method

Abstract

This motor control device controls a motor. The motor comprises a rotor, a stator, and a Hall sensor. The stator has multi-phase windings. The Hall sensor detects the rotation position of the rotor. The motor control device comprises an inverter circuit, an estimation unit, an energization control unit, and a correction unit. The inverter circuit applies a driving voltage to the multi-phase windings. The estimation unit estimates the position of the rotor on the basis of the change of a magnetic pole detected by the Hall sensor. The energization control unit controls an energization timing to each of the multi-phase windings on the basis of the estimated position of the rotor. The correction unit corrects the energization timing on the basis of misalignment between each of the multi-phase windings and the Hall sensor. The correction unit determines a correction value on the basis of an extreme value of the rotational speed when the setting position of the Hall sensor is changed under open control.

Description

[Technical Field]

[0001] The present invention relates to a motor control device, a motor module, and a motor control method. [Background technology]

[0002] The brushless motor control device described in Patent Document 1 includes an inverter circuit, a rotor magnetic pole detection unit, a rotor position estimation unit, a current detection unit, and an electrical angle correction unit. The electrical angle correction unit determines an electrical angle offset based on fluctuations in the power supply current value, and corrects the estimated rotor position signal by adding the electrical angle offset to the electrical angle indicated by the estimated rotor position signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 79052 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the brushless motor control device described in Patent Document 1 requires a circuit for reading the power supply current, which may result in an increase in the size of the circuit.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a motor control device, a motor module, and a motor control method that can correct the positional misalignment between the windings of each phase and the Hall sensor while suppressing an increase in the size of the circuit. [Means for solving the problem]

[0006] An exemplary motor control device of the present invention controls a motor. The motor includes a rotor, a stator, and a Hall sensor. The stator has windings for multiple phases. The Hall sensor detects the rotational position of the rotor. The motor control device includes an inverter circuit, an estimator, an energization controller, and a corrector. The inverter circuit applies a drive voltage to the windings for multiple phases. The estimator estimates the position of the rotor based on changes in magnetic poles detected by the Hall sensor. The energization controller controls the timing of energization to the windings for each phase based on the estimated position of the rotor. The corrector corrects the energization timing based on a positional deviation between the windings for each phase and the Hall sensor. The corrector determines a correction value based on extreme values ​​of the rotational speed when the set position of the Hall sensor is changed under open control.

[0007] An exemplary motor module of the present invention includes the motor control device described above and a motor. The motor is controlled by the motor control device. The motor includes a rotor, a stator, and a Hall sensor. The stator has multiple phase windings. The Hall sensor detects the rotational position of the rotor.

[0008] An exemplary motor control method of the present invention controls a motor. The motor includes a rotor, a stator, and a Hall sensor. The stator has windings for multiple phases. The Hall sensor detects the rotational position of the rotor. The motor control method includes an acquisition step, a determination step, and a correction step under open control. In the acquisition step, the set position of the Hall sensor is changed to acquire the rotational speed of the motor. In the determination step, a correction value is determined based on an extreme value of the acquired rotational speed. In the correction step, the timing of energization of the windings for each phase is corrected based on the correction value. [Effects of the Invention]

[0009] According to the exemplary embodiment of the present invention, it is possible to correct the misalignment between the windings of each phase and the Hall sensors while suppressing an increase in the size of the circuit. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram of a motor module according to an embodiment of the present invention. [Figure 2] FIG. 2 is a circuit diagram showing an inverter circuit. [Figure 3] FIG. 3 is a schematic diagram showing a motor. [Figure 4] FIG. 4 is a diagram showing the back electromotive force and the Hall sensor signal. [Figure 5] FIG. 5 is a diagram showing the absolute value of the rotation speed relative to the Hall sensor setting position. [Figure 6] FIG. 6 is a diagram showing the absolute value of the rotation speed relative to the Hall sensor setting position. [Figure 7] FIG. 7 is a diagram showing the rotation speed. [Figure 8] FIG. 8 is a diagram for explaining a method for determining the rotation speed. [Figure 9] FIG. 9 is a diagram for explaining a method for determining the rotation speed. [Figure 10] FIG. 10 is a diagram for explaining a method for determining an extreme value of the rotation speed. [Figure 11A] FIG. 11A is a diagram showing the setting positions of the Hall sensors. [Figure 11B] FIG. 11B is a diagram showing the setting positions of the Hall sensors. [Figure 12] FIG. 12 is a diagram for explaining a method for determining an extreme value of the rotation speed. [Figure 13] FIG. 13 is a diagram showing the positions where the Hall sensors are set. [Figure 14] FIG. 14 is a diagram for explaining a method for determining an extreme value of the rotation speed. [Figure 15] FIG. 15 is a diagram for explaining a method for determining an extreme value of the rotation speed. [Figure 16] FIG. 16 is a flowchart illustrating a motor control method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0012] A motor module 200 according to an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a block diagram of the motor module 200 according to an embodiment of the present invention. Fig. 2 is a circuit diagram showing an inverter circuit 110. Fig. 3 is a schematic diagram showing a motor M.

[0013] 1, the motor module 200 includes a motor control device 100 and a motor M. The motor M is controlled by the motor control device 100. The motor M is, for example, a brushless DC motor. The motor M has a U phase, a V phase, and a W phase.

[0014] The motor control device 100 controls the motor M. More specifically, the motor control device 100 controls the driving of the motor M. The motor control device 100 includes an inverter circuit 110 and a control device 120.

[0015] The motor control device 100 outputs a three-phase AC output. The motor control device 100 has three output terminals 102. The three output terminals 102 include an output terminal 102u, an output terminal 102v, and an output terminal 102w. The three output terminals 102 output three-phase output voltages and three-phase output currents to the motor M. Specifically, the output terminal 102u outputs a U-phase output voltage Vu and a U-phase output current Iu to the motor M. The output terminal 102v outputs a V-phase output voltage Vv and a V-phase output current Iv to the motor M. The output terminal 102w outputs a W-phase output voltage Vw and a W-phase output current Iw to the motor M.

[0016] The inverter circuit 110 applies a drive voltage to windings of multiple phases, which will be described later with reference to FIG.

[0017] 2, the motor control device 100 includes a first power supply terminal P, a second power supply terminal N, a capacitor C, and three series bodies 112. More specifically, in this embodiment, the motor control device 100 includes an inverter circuit 110, which includes a first power supply terminal P, a second power supply terminal N, a capacitor C, and three series bodies 112. The inverter circuit 110 further includes a DC voltage source B. Note that the DC voltage source B may be external to the inverter circuit 110.

[0018] A first voltage V1 is applied to a first power supply terminal P. The first power supply terminal P is connected to a DC voltage source B.

[0019] A second voltage V2 is applied to the second power supply terminal N. The second power supply terminal N is connected to a DC voltage source B. The second voltage V2 is lower than the first voltage V1.

[0020] The capacitor C is connected between the first power supply terminal P and the second power supply terminal N.

[0021] Two semiconductor switching elements are connected in series to the three series bodies 112. The semiconductor switching elements are, for example, IGBTs (insulated gate bipolar transistors). The semiconductor switching elements may also be other transistors such as field-effect transistors. The three series bodies 112 include a series body 112u, a series body 112v, and a series body 112w. The three series bodies 112 are connected in parallel to one another. One end of each of the three series bodies 112 is connected to a first power supply terminal P. The other end of each of the three series bodies 112 is connected to a second power supply terminal N. A rectifying element D is connected in parallel to each of these semiconductor switching elements, with the first power supply terminal P side (upper side of the drawing) serving as the cathode and the second power supply terminal N side (lower side of the drawing) serving as the anode. When field-effect transistors are used as the semiconductor switching elements, a parasitic diode may be used as the rectifying element.

[0022] Each of the three series bodies 112 has a first semiconductor switching element and a second semiconductor switching element. Specifically, the series body 112u has a first semiconductor switching element Up and a second semiconductor switching element Un. The series body 112v has a first semiconductor switching element Vp and a second semiconductor switching element Vn. The series body 112w has a first semiconductor switching element Wp and a second semiconductor switching element Wn.

[0023] The first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are connected to the first power supply terminal P. In other words, the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are semiconductor switching elements on the high-voltage side.

[0024] The second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are connected to the second power supply terminal N. In other words, the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are semiconductor switching elements on the low-voltage side.

[0025] The first semiconductor switching element and the second semiconductor switching element are connected at a connection point 114. More specifically, the first semiconductor switching element Up and the second semiconductor switching element Un are connected at a connection point 114u. The first semiconductor switching element Vp and the second semiconductor switching element Vn are connected at a connection point 114v. The first semiconductor switching element Wp and the second semiconductor switching element Wn are connected at a connection point 114w.

[0026] Connection point 114 in each of the three series bodies 112 is connected to three output terminals 102. Specifically, connection point 114u in series body 112u is connected to output terminal 102u. Connection point 114v in series body 112v is connected to output terminal 102v. Connection point 114w in series body 112w is connected to output terminal 102w.

[0027] PWM signals are input to the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp. The PWM signals are output from the control device 120. Hereinafter, in this specification, the PWM signal input to the first semiconductor switching element Up may be referred to as the "UpPWM signal." The PWM signal input to the first semiconductor switching element Vp may be referred to as the "VpPWM signal." The PWM signal input to the first semiconductor switching element Wp may be referred to as the "WpPWM signal." The first semiconductor switching elements Up, Vp, and Wp are switched on and off at a frequency higher than the frequency of the AC output. For example, the first semiconductor switching elements Up, Vp, and Wp are turned on when the UpPWM signal, VpPWM signal, and WpPWM signal are at a HIGH level, respectively. On the other hand, the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are turned off when the UpPWM signal, the VpPWM signal, and the WpPWM signal are at a low level, respectively.

[0028] PWM signals are input to the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn. The PWM signals are output from the control device 120. Hereinafter, in this specification, the PWM signal input to the second semiconductor switching element Un may be referred to as the "UnPWM signal." The PWM signal input to the second semiconductor switching element Vn may be referred to as the "VnPWM signal." The PWM signal input to the second semiconductor switching element Wn may be referred to as the "WnPWM signal." The second semiconductor switching elements Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are switched on and off at a frequency higher than the frequency of the AC output. For example, the second semiconductor switching elements Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are turned on when the UnPWM signal, the VnPWM signal, and the WnPWM signal are at a HIGH level, respectively. On the other hand, the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are turned off when the UnPWM signal, the VnPWM signal, and the WnPWM signal are at a low level, respectively.

[0029] As shown in FIG. 3, the motor M includes a rotor 310, a stator 320, and three Hall sensors 330.

[0030] The rotor 310 is disposed about a central axis AX extending in a direction perpendicular to the plane of the drawing. That is, as an example, the motor M is an inner rotor type motor. The rotor 310 rotates about the central axis AX. The rotor 310 is disposed radially inward of the stator 320 in the radial direction RD.

[0031] The stator 320 is disposed about a central axis AX extending in a direction perpendicular to the paper surface. The stator 320 faces the rotor 310 in the radial direction RD. The stator 320 has multi-phase windings 322. In this embodiment, the stator 320 has three-phase windings 322.

[0032] The three Hall sensors 330 include a Hall sensor 332, a Hall sensor 334, and a Hall sensor 336. The Hall sensor 332 is a Hall sensor for the U phase. The Hall sensor 334 is a Hall sensor for the V phase. The Hall sensor 336 is a Hall sensor for the W phase. The Hall sensors 330 are, for example, magnetic sensors. The Hall sensors 330 detect the rotational position of the rotor 310.

[0033] 1, motor control device 100 includes an estimator 122, an energization controller 124, and a corrector 126. More specifically, in this embodiment, motor control device 100 includes a control device 120, which includes estimator 122, energization controller 124, and corrector 126. Control device 120 is a hardware circuit configured with a processor such as a CPU (Central Processing Unit) and an ASIC (Application Specific Integrated Circuit), etc. The processor of control device 120 functions as estimator 122, energization controller 124, and corrector 126 by executing a computer program stored in a storage device.

[0034] The control device 120 controls the inverter circuit 110. Specifically, the control device 120 generates a PWM signal and outputs the PWM signal to control the inverter circuit 110. More specifically, the control device 120 generates a PWM signal to be input to each of the three series bodies 112.

[0035] The estimation unit 122 estimates the position of the rotor 310 based on the change in magnetic pole detected by the Hall sensor 330 .

[0036] The energization control unit 124 controls the timing of energizing the windings 322 of each phase based on the estimated position of the rotor 310.

[0037] Correction unit 126 corrects the energization timing based on the positional deviation between winding 322 of each phase and Hall sensor 330. How the correction value is determined will be described later with reference to FIGS.

[0038] The misalignment between the Hall sensor 330 and the winding 322 of each phase will be described with reference to Fig. 4. Fig. 4 is a diagram showing the back electromotive force and the Hall sensor signal. In Fig. 4, the back electromotive force is shown by a dashed line, and the Hall sensor signal is shown by a solid line.

[0039] As shown in Figure 4, the waveform of the back electromotive force is sinusoidal. The position of the winding 322 of the stator 320 corresponds to the waveform of the back electromotive force. The Hall sensor signal is a square wave.

[0040] The value α is determined by the positional relationship between the position of the winding 322 of the stator 320 and the Hall sensor 330. An attachment error between the winding 322 of the stator 320 and the Hall sensor 330 causes a deviation Δα in the Hall sensor signal.

[0041] A method for correcting the positional deviation between the Hall sensor 330 and the winding 322 of each phase will be described with reference to Figure 5. Figure 5 is a diagram showing the absolute value of the rotational speed relative to the Hall sensor setting position. In Figure 5, the horizontal axis indicates the Hall sensor setting position. In Figure 5, the vertical axis indicates the absolute value of the rotational speed. In Figure 5, circles indicate the absolute value of the rotational speed when the motor M rotates in the CW direction (clockwise direction). In Figure 5, triangles indicate the absolute value of the rotational speed when the motor M rotates in the CCW direction (counterclockwise direction).

[0042] As shown in Figure 5, the rotation speed in the CW direction reaches an extreme value at position P1, where the Hall sensor is installed at an electrical angle of 48 degrees.

[0043] The CCW rotation speed reaches an extreme value at P2, where the Hall sensor is installed at an electrical angle of 45 degrees.

[0044] The correction unit 126 determines the correction value based on the extreme value of the rotation speed when the set position of the Hall sensor 330 is changed under open control. For example, the correction unit 126 acquires the rotation speed when the set position of the Hall sensor 330 is changed under open control. The correction unit 126 then determines the set value of the Hall sensor 330 to be position P3, which is the average of position P1 where the rotation speed in the CW direction is at its extreme value and position P2 where the rotation speed in the CCW direction is at its extreme value. Position P3 is an electrical angle of 46.5 degrees. The correction unit 126 sets the set position of the Hall sensor 330 to 46.5 degrees and corrects the energization timing. In this way, the correction unit 126 determines the correction value based on the extreme value of the rotation speed when the set position of the Hall sensor 330 is changed under open control. This makes it possible to correct the positional misalignment between the windings of each phase and the Hall sensor 330 while suppressing an increase in circuit size.

[0045] A method for correcting the positional deviation between the Hall sensor 330 and the winding 322 of each phase will be described with reference to FIG. 6. FIG. 6 is a diagram showing the absolute value of the rotational speed relative to the Hall sensor setting position. In FIG. 6, the horizontal axis indicates the Hall sensor setting position. In FIG. 6, the vertical axis indicates the absolute value of the rotational speed. In FIG. 6, the circles indicate the absolute value of the rotational speed when the motor M rotates in the CW direction (clockwise direction). In FIG. 6, the triangles indicate the absolute value of the rotational speed when the motor M rotates in the CCW direction (counterclockwise direction). The data shown in FIG. 6 shows data for a motor M different from the data shown in FIG. 5.

[0046] As shown in Figure 5, the rotation speed in the CW direction reaches an extreme value at position P1, where the Hall sensor is installed at an electrical angle of 28 degrees.

[0047] The CCW rotation speed reaches an extreme value at P2, where the Hall sensor is installed at an electrical angle of 37 degrees.

[0048] The correction unit 126 determines the correction value based on the extreme value of the rotation speed when the set position of the Hall sensor 330 is changed under open control. For example, the correction unit 126 acquires the rotation speed when the set position of the Hall sensor 330 is changed under open control. The correction unit 126 then determines the set value of the Hall sensor 330 to be position P3, which is the average of position P1 where the rotation speed in the CW direction is at its extreme value and position P2 where the rotation speed in the CCW direction is at its extreme value. Position P3 is an electrical angle of 32.5 degrees. The correction unit 126 sets the set position of the Hall sensor 330 to 32.5 degrees and corrects the energization timing. In this way, the correction unit 126 determines the correction value based on the extreme value of the rotation speed when the set position of the Hall sensor 330 is changed under open control. This makes it possible to correct the positional misalignment between the windings of each phase and the Hall sensor 330 while suppressing an increase in circuit size.

[0049] The timing for acquiring the rotation speed will be described with reference to FIG. 7. FIG. 7 is a diagram showing the rotation speed. In FIG. 7, the horizontal axis represents the elapsed time since the Hall sensor setting position was changed. In FIG. 7, the vertical axis represents the absolute value of the rotation speed. The data shown in FIG. 7, from the bottom up, shows data when the Hall sensor setting position is changed from an electrical angle of 30 degrees to an electrical angle of 31 degrees, data when the Hall sensor setting position is changed from an electrical angle of 31 degrees to an electrical angle of 32 degrees, data when the Hall sensor setting position is changed from an electrical angle of 32 degrees to an electrical angle of 33 degrees, data when the Hall sensor setting position is changed from an electrical angle of 33 degrees to an electrical angle of 34 degrees, data when the Hall sensor setting position is changed from an electrical angle of 34 degrees to an electrical angle of 35 degrees, and data when the Hall sensor setting position is changed from an electrical angle of 35 degrees to an electrical angle of 36 degrees.

[0050] 7, the rotation speed converges as time passes after the setting position of the Hall sensor is changed. Therefore, when the correction unit 126 changes the setting position of the Hall sensor 330 and acquires the rotation speed, the correction unit 126 acquires the rotation speed after a certain time has elapsed since the setting position of the Hall sensor 330 was changed. Therefore, by acquiring the converged value of the rotation speed, an accurate rotation speed can be acquired.

[0051] Determination of the rotation speed will be described with reference to Figures 8 and 9. Figures 8 and 9 are diagrams for explaining a method of determining the rotation speed. In Figure 8, the horizontal axis represents time, and the vertical axis represents the rotation speed.

[0052] 8, there is a possibility that the rotation speed may fluctuate slightly depending on the motor M. Therefore, the correction unit 126 considers that the rotation speed has converged when the fluctuation of the rotation speed falls within a certain range.

[0053] When the setting position of the Hall sensor 330 is changed to acquire the rotation speed, the correction unit 126 stores at least one of the maximum value and the minimum value of the multiple instantaneous speeds over multiple predetermined periods. In this embodiment, when the setting position of the Hall sensor 330 is changed to acquire the rotation speed, the correction unit 126 stores the maximum value and the minimum value of the multiple instantaneous speeds over multiple predetermined periods. Note that when the setting position of the Hall sensor 330 is changed to acquire the rotation speed, the correction unit 126 may store only the maximum value of the multiple instantaneous speeds over multiple predetermined periods. Alternatively, when the setting position of the Hall sensor 330 is changed to acquire the rotation speed, the correction unit 126 may store only the minimum value of the multiple instantaneous speeds over multiple predetermined periods.

[0054] Specifically, the correction unit 126 defines a predetermined period as a block BL, and stores the maximum value U1 and the minimum value L1 of the multiple instantaneous speeds in each block BL.

[0055] As shown in FIG. 9 , correction unit 126 determines the rotation speed based on the maximum value and / or the minimum value when at least one of the variations in the maximum value and the variations in the minimum value over multiple predetermined periods falls within a certain range. In this embodiment, correction unit 126 determines the rotation speed based on the maximum value and the minimum value when the variations in the maximum value and the variations in the minimum value over multiple predetermined periods fall within a certain range. Note that correction unit 126 may determine the rotation speed based on the maximum value when the variations in the maximum value over multiple predetermined periods fall within a certain range. Alternatively, correction unit 126 may determine the rotation speed based on the minimum value when the variations in the minimum value over multiple predetermined periods fall within a certain range.

[0056] Specifically, in one example of the correction unit 126, the rotation speed is deemed to have converged if the maximum value Umax and the minimum value Umin fall within ±0.1% of the midpoint Umid between the maximum value Umax of the maximum value U1 and the minimum value Umin of the maximum value U1 in the most recent five blocks BL.

[0057] In another example of the correction unit 126, the rotation speed is considered to have converged if it falls within ±0.1% of the midpoint Lmid between the maximum value Lmax of the minimum value L1 and the minimum value Lmin of the minimum value L1 in the most recent five blocks BL.

[0058] Another example of the correction unit 126 determines the rotation speed based on the maximum and minimum values. Specifically, when the maximum value U1 and the minimum value L1 converge, the correction unit 126 determines the intermediate value spd_mid between the intermediate values ​​Umid and Lmid as the rotation speed. Therefore, even if the instantaneous rotation speed increases or decreases due to mechanical vibration, an accurate rotation speed can be obtained. Furthermore, the convergence of the rotation speed can be detected quickly.

[0059] An example of a method for determining the extreme value of the rotation speed will be described with reference to Fig. 10. Fig. 10 is a diagram for explaining a method for determining the extreme value of the rotation speed.

[0060] 10, the Hall sensor setting position is first set to a typical value. The typical value indicates the position where the Hall sensor 330 should be installed. For example, the typical value is a potential angle of 45 degrees.

[0061] The scanning direction from the typical value is initialized to positive, the scanning amount to Δθ, and the previous rotation speed to 0. Then, the rotation speed at the typical value P31 is obtained.

[0062] Next, as shown in "1" in Figure 10, the rotation speed is acquired at the Hall sensor setting position P32, which is scanned by Δθ in the positive direction from the typical value P31. If it is smaller than the previous rotation speed, the scanning direction is reversed. In this case, since the rotation speed is smaller than the previous rotation speed, the scanning direction is reversed to the negative direction.

[0063] Next, as shown in "2" in Figure 10, the rotation speed is acquired at the Hall sensor setting position P33, which is scanned by Δθ in the negative direction from the typical value P31. Since the rotation speed is greater than the previous rotation speed, the scanning direction is maintained in the negative direction.

[0064] Next, as shown by "3" in Figure 10, the rotation speed is acquired at Hall sensor setting position P34, which is scanned by Δθ in the negative direction from Hall sensor setting position P33. Since the rotation speed is greater than the previous rotation speed, the scanning direction is maintained in the negative direction.

[0065] Next, as shown by "4" in Figure 10, the rotation speed is acquired at Hall sensor setting position P34, which is scanned by Δθ in the negative direction from Hall sensor setting position P34. Since the rotation speed is smaller than the previous rotation speed, the scanning direction is reversed to the positive direction.

[0066] Next, as shown by "5" in FIG. 10, the rotation speed is acquired at a Hall sensor set position P36, which is scanned by Δθ / 2 in the forward direction from the Hall sensor set position P34.

[0067] In this way, by acquiring the rotation speed while scanning, it is possible to determine the extreme values ​​of the rotation speed, and as a result, it is possible to determine the setting positions of the Hall sensors corresponding to the extreme values ​​of the rotation speed.

[0068] 11A and 11B, the measurement results of the Hall sensor setting position using the method described in FIG. 10 will be described. FIGS. 11A and 11B are diagrams showing the Hall sensor setting positions. FIG. 11A shows the measurement results of the Hall sensor setting position in the CW (clockwise) direction. FIG. 11B shows the measurement results of the Hall sensor setting value in the CCW (counterclockwise) direction. In FIGS. 11A and 11B, the horizontal axis indicates the number of scans of the Hall sensor setting position. In FIGS. 11A and 11B, the vertical axis indicates the Hall sensor setting position. FIGS. 11A and 11B show the measurement results of the Hall sensor setting value when the initial value of the Hall sensor setting position is set to an electrical angle of 52 degrees, 50 degrees, 48 ​​degrees, 46 degrees, 44 degrees, 42 degrees, 40 degrees, and 38 degrees.

[0069] 11A and 11B, even if the initial values ​​of the Hall sensor setting positions are varied, the Hall sensor setting positions can be converged to within a range of ±1 electrical degree. In other words, regardless of the magnitude of the deviation from the typical value, the Hall sensor setting positions of the motor M to be corrected can be accurately determined.

[0070] An example of a method for determining the extreme value of the rotation speed will be described with reference to Fig. 12. Fig. 12 is a diagram for explaining a method for determining the extreme value of the rotation speed.

[0071] In the example shown in FIG. 12, the correction unit 126 acquires multiple rotation speeds by scanning the setting positions of the Hall sensor 330 near the typical value. In this embodiment, the correction unit 126 acquires rotation speeds in a range of ±10 degrees in electrical angle from the typical value P5. The correction unit 126 calculates the setting positions of the Hall sensor 330 corresponding to the extreme values ​​by performing a polynomial approximation of the multiple rotation speeds of second or higher order. In this embodiment, the correction unit 126 calculates the setting positions of the Hall sensor 330 corresponding to the extreme values ​​by performing a parabolic approximation of the multiple rotation speeds. The parabolic approximation is performed by, for example, the least squares method. The parabola y=ax calculated by the least squares method is 2In +bx+c, the x-coordinate corresponding to the extreme value, i.e., the setting position of the Hall sensor 330 corresponding to the extreme value, can be calculated by finding -b / 2a. Note that the correction unit 126 may calculate the setting position of the Hall sensor 330 corresponding to the extreme value by performing a polynomial approximation of the multiple rotation speeds with a degree of third or higher.

[0072] The correction unit 126 determines the correction value based on the calculated setting position of the Hall sensor 330. Therefore, the correction value can be determined appropriately.

[0073] With reference to Fig. 13, the measurement results of the Hall sensor setting positions using the method described in Fig. 12 will be described. Fig. 13 is called a QQ plot (Quantile-Quantile Plot), and shows the distribution of the Hall sensor setting positions according to the number of trials. In Fig. 13, the number of attempts to determine the Hall sensor setting positions is the number of plots, and the horizontal axis indicates the Hall sensor setting positions determined in each trial. In Fig. 13, the vertical axis indicates the normal distribution probability (%).

[0074] As shown in Figure 13, the Hall sensor setting position can be converged to within the range of ±0.38 electrical degrees with a probability of 96%. Therefore, the correction value can be determined appropriately.

[0075] An example of a method for determining the extreme values ​​of the rotation speed will be described with reference to Fig. 14 and Fig. 15. Fig. 14 and Fig. 15 are diagrams for explaining a method for determining the extreme values ​​of the rotation speed. Fig. 14 shows the absolute value of the rotation speed when the motor M rotates in the CW direction (clockwise direction). Fig. 15 shows the absolute value of the rotation speed when the motor M rotates in the CCW direction (counterclockwise direction).

[0076] As shown in FIG. 14 , the correction unit 126 scans the set positions of the Hall sensor 330 starting from the retarded side. Specifically, for example, scanning of the set positions begins from position P11, which is 14 electrical degrees smaller than the typical value. Then, by calculating the slope of the open control rotation speed for the two or more most recent set positions of the Hall sensor 330, the correction unit 126 detects the point where the absolute value of the rotation speed changes from decreasing to increasing. Specifically, the absolute value of the rotation speed increases from position P11 to position P12. The absolute value of the rotation speed decreases from position P12 to position P14. The correction unit 126 determines the correction value by polynomial approximation of the relationship between the set positions of the Hall sensor 330 and the open control rotation speed until the change to increasing. The absolute value of the rotation speed increases from position P14 to position P15. The correction unit 126 determines the correction value by performing a polynomial approximation of the relationship between the setting position of the Hall sensor 330 on the slower (smaller) angle side including position P13 and the rotation speed under open control using a second- or higher-order polynomial. In this embodiment, the correction unit 126 determines the correction value by performing a parabolic approximation of the relationship between the setting position of the Hall sensor 330 on the slower (smaller) angle side including position P13 and the rotation speed under open control. This allows for an appropriate correction value to be determined. The correction unit 126 may also determine the correction value by performing a polynomial approximation of the relationship between the setting position of the Hall sensor 330 on the slower (smaller) angle side including position P13 and the rotation speed under open control using a third- or higher-order polynomial. In this embodiment, the rotation speed is measured up to position P15, which is necessary to determine the range for parabolic approximation, but scanning beyond that position is not performed. This reduces the time required to determine the correction value.

[0077] As shown in FIG. 15 , the correction unit 126 scans the setting positions of the Hall sensor 330 starting from the retard side. Specifically, for example, scanning of the setting positions begins from position P21, which is 14 electrical degrees greater than the typical value. Then, by calculating the slope of the rotation speed under open control for the two or more most recent setting positions of the Hall sensor 330, the correction unit 126 detects the point where the absolute value of the rotation speed changes from decreasing to increasing. Specifically, the absolute value of the rotation speed increases from position P21 to position P22. The absolute value of the rotation speed decreases from position P22 to position P24. The correction unit 126 determines the correction value by polynomial approximation of the relationship between the setting positions of the Hall sensor 330 and the rotation speed under open control until the change to increasing. Specifically, the absolute value of the rotation speed increases from position P24 to position P25. The correction unit 126 determines the correction value by performing a polynomial approximation of the relationship between the setting position of the Hall sensor 330 on the slower (larger) angle side including position P23 and the rotational speed under open control using a second- or higher-order polynomial. In this embodiment, the correction unit 126 determines the correction value by performing a parabolic approximation of the relationship between the setting position of the Hall sensor 330 on the slower (larger) angle side including position P23 and the rotational speed under open control. This allows for an appropriate correction value to be determined. The correction unit 126 may also determine the correction value by performing a polynomial approximation of the relationship between the setting position of the Hall sensor 330 on the slower (larger) angle side including position P23 and the rotational speed under open control using a third- or higher-order polynomial. In this embodiment, the rotational speed is measured up to position P25, which is necessary to determine the range for parabolic approximation, but scanning beyond that point is not performed. This reduces the time required to determine the correction value.

[0078] A motor control method according to an embodiment of the present invention will be described with reference to Fig. 16. Fig. 16 is a flowchart showing a motor control method according to an embodiment of the present invention. The processes of steps S102 to S106 are performed under open control, thereby performing motor control.

[0079] Step S102: The correction unit 126 changes the setting position of the Hall sensor 330 to acquire the rotation speed of the motor M. The process proceeds to step S104. Note that step S102 is an example of an "acquisition step".

[0080] Step S104: The correction unit 126 determines a correction value based on the acquired extreme value of the rotation speed. The process proceeds to step S106. Note that step S104 is an example of a "determining step".

[0081] Step S106: The correction unit 126 corrects the energization timing of the winding of each phase based on the correction value. The process ends. Note that step S106 is an example of a "correction step."

[0082] As described above with reference to FIG. 16 , the motor control method includes an obtaining step, a determining step, and a correcting step. In the correcting step, the timing of energizing the windings of each phase is corrected based on the correction value. This makes it possible to correct the misalignment between the windings 322 of each phase and the Hall sensors 330 while suppressing an increase in the circuit size.

[0083] The embodiments of the present invention have been described above with reference to the drawings (FIGS. 1 to 16). However, the present invention is not limited to the above-described embodiments and can be embodied in various forms without departing from the spirit of the present invention. The drawings mainly show each component in a schematic manner for ease of understanding, and the thickness, length, number, etc. of each component shown in the drawings may differ from the actual components due to the convenience of creating the drawings. Furthermore, the materials, shapes, dimensions, etc. of each component shown in the above-described embodiments are merely examples and are not particularly limited, and various modifications are possible within a range that does not substantially depart from the effects of the present invention. [Industrial Applicability]

[0084] The present invention can be suitably used in a power conversion device, a motor module, and a motor control method. [Explanation of symbols]

[0085] 100 Motor control device 110 Inverter circuit 120 Control device 122 Estimation Department 124 Power supply control unit 126 Correction Unit 200 Motor Module 310 rotor 320 Stator 322 windings 330, 332, 334, 336 Hall sensors Medium motor

Claims

1. A motor control device that controls a motor, The motor A rotor, a stator having windings for multiple phases; a Hall sensor for detecting the rotational position of the rotor; The motor control device includes: an inverter circuit that applies a drive voltage to the windings of the plurality of phases; an estimation unit that estimates a position of the rotor based on a change in magnetic pole detected by the Hall sensor; an energization control unit that controls the energization timing of the windings of each phase based on the estimated rotor position; a correction unit that corrects the energization timing based on a positional deviation between the winding of each phase and the Hall sensor, The correction unit determines a correction value for correcting the energization timing according to the setting position of the Hall sensor that corresponds to the extreme value of the rotational speed of the motor when the setting position of the Hall sensor is changed and the motor is driven.

2. 2. The motor control device according to claim 1, wherein when the correction unit acquires the rotational speed by changing the setting position of the Hall sensor, the correction unit acquires the rotational speed after a certain time has elapsed since the setting position of the Hall sensor was changed.

3. 3. The motor control device according to claim 1, wherein the correction unit, when changing the setting position of the Hall sensor to acquire the rotational speed, stores at least one of the maximum and minimum values ​​of multiple instantaneous speeds over multiple predetermined periods, and determines the rotational speed based on the maximum and / or minimum value if at least one of the variations in the maximum value and the variations in the minimum value over multiple predetermined periods falls within a certain range.

4. 4. The motor control device according to claim 3, wherein when the correction unit acquires the rotational speed by changing the setting position of the Hall sensor, it stores maximum and minimum values ​​among multiple instantaneous speeds over multiple predetermined periods, and determines the rotational speed based on the maximum and minimum values ​​if variations in the maximum and minimum values ​​over the multiple predetermined periods fall within a certain range.

5. 5. The motor control device according to claim 1, wherein the correction unit acquires the plurality of rotational speeds by scanning the setting positions of the Hall sensor near a typical value, calculates the setting positions of the Hall sensor corresponding to the extreme value by polynomial approximation of the plurality of rotational speeds by second- or higher-order polynomials, and determines the correction value based on the calculated setting positions of the Hall sensor.

6. 6. The motor control device according to claim 5, wherein the correction unit detects a point where the absolute value of the rotational speed changes from decreasing to increasing by scanning the setting positions of the Hall sensor from the retard side of the setting positions of the Hall sensor and calculating a gradient of the rotational speed under open control for two or more of the most recent setting positions of the Hall sensor, and determines the correction value by polynomial approximation of the relationship between the setting positions of the Hall sensor and the rotational speed under open control until the change to increasing.

7. The motor control device according to any one of claims 1 to 6, a motor controlled by the motor control device, The motor A rotor, a stator having windings for multiple phases; a Hall sensor that detects the rotational position of the rotor.

8. A motor control method for controlling a motor, comprising: The motor A rotor, a stator having windings for multiple phases; a Hall sensor for detecting the rotational position of the rotor; The motor control method includes: an acquiring step of acquiring a rotation speed of the motor when the motor is driven with the setting position of the Hall sensor changed; a determination step of determining a correction value for correcting the timing of energizing the windings of each phase in accordance with a setting position of the Hall sensor corresponding to the acquired extreme value of the rotation speed; and correcting the timing of energizing the windings of each phase based on the correction value.

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