JP4221861B2 - Motor control device and motor control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor control device and a motor control method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an electric vehicle, a motor including a stator having U-phase, V-phase, and W-phase stator coils, and a rotor that is rotatably disposed inside the stator and has a magnetic pole pair is used. The motor is driven by supplying U-phase, V-phase, and W-phase currents to the stator coil by a control device.
[0003]
FIG. 2 is a diagram showing a conventional motor control device.
[0004]
In the figure, 20 is a motor control device, 21 is a motor, 22 is an inverter for supplying current to the motor 21, 23 is a control circuit, 24 is a command value generator for generating a current command value, and 25 is the motor 21. This is a resolver for detecting the position of the magnetic pole of the rotor (not shown), that is, the magnetic pole position. The command value generator 24 is disposed in a vehicle control circuit (not shown) that controls the entire electric vehicle.
[0005]
A motor control unit (not shown) in the control circuit 23 receives a current command value from the command value generating unit 24, and has U-phase, V-phase, and W-phase pulse widths having pulse widths corresponding to the current command value. A modulation signal is generated, and the pulse width modulation signal is sent to a drive circuit (not shown) in the control circuit 23.
[0006]
The drive circuit generates a drive signal corresponding to the pulse width modulation signal and sends the drive signal to the inverter 22. The inverter 22 has six transistors as switching elements (not shown), and the transistors 22 are turned on only while the drive signal is on, so that the current I of each phase_U, I_V, I_WEach current I_U, I_V, I_WIs supplied to a stator coil (not shown) of the motor 21. In this way, the motor 21 is driven by operating the motor control unit, and the electric vehicle is caused to travel.
[0007]
By the way, since the stator coil is star-connected, each current I_U, I_V, I_WWhen the current values of the two phases are determined, the current values of the remaining one phase are also determined. Therefore, the current I of each phase_U, I_V, I_WFor example, the U-phase and V-phase currents I_U, I_VIs detected by a current sensor not shown, and the detected current I_U, I_VDetection signal SG_U, SG_VIs sent to the control circuit 23. Then, feedback control is performed by vector control calculation on a dq axis model in which the d axis is taken in the direction of the magnetic pole pair of the rotor (not shown) of the motor 21 and the q axis is taken in the direction perpendicular to the d axis.
[0008]
For this purpose, the magnetic pole position is detected by the resolver 25, and the motor control unit detects the detection signal SG._U, SG_VAnd three-phase / two-phase conversion is performed based on the detected magnetic pole position, that is, the detected magnetic pole position θ, and the detection signal SG_U, SG_VThe detected magnetic pole position θ is converted into a d-axis current and a q-axis current. Then, a d-axis current deviation between the d-axis current and the d-axis current command value and a q-axis current deviation between the q-axis current and the q-axis current command value are respectively calculated, and the d-axis current deviation and the q-axis current deviation are calculated. A d-axis voltage command value and a q-axis voltage command value are generated as inverter outputs on the two axes so as to be zero. Subsequently, the d-axis voltage command value and the q-axis voltage command value are converted into U-phase, V-phase, and W-phase voltage command values by performing two-phase / three-phase conversion based on the detected magnetic pole position θ, U-phase, V-phase, and W-phase pulse width modulation signals are generated based on the voltage command values of the respective phases.
[0009]
[Problems to be solved by the invention]
However, since the resolver 25 is used to detect the magnetic pole position in the conventional motor control device 20, the detection accuracy of the magnetic pole position and the controllability of the motor are improved, but the cost of the motor control device 20 is high. turn into.
[0010]
Therefore, it is conceivable to use a simple magnetic pole position detection sensor, for example, a Hall element, instead of the resolver 25.
[0011]
FIG. 3 is a waveform diagram of the sensor output and detection magnetic pole position of the conventional Hall element, and FIG. 4 is a time chart showing the operation of the conventional inverter.
[0012]
In the figure, S1 to S3 are sensor outputs of the Hall elements, and the sensor outputs S1 to S3 switch their signal levels every 180 [deg.] In electrical angle, and have phases of 60 [deg] in electrical angle. It is generated by shifting. Further, θ is a detected magnetic pole position generated based on the sensor outputs S1 to S3. In this case, since the magnetic pole position can be detected with a resolution of 6 steps in one cycle of the electrical angle, the cost of the motor control device 20 (FIG. 2) can be reduced.
[0013]
However, since the Hall element has a low resolution, the detection accuracy of the magnetic pole position is lowered accordingly, and a positional deviation occurs between the detected magnetic pole position θ and the actual magnetic pole position, that is, the actual magnetic pole position. In addition, since the detected magnetic pole position θ changes stepwise every 60 ° in electrical angle, when the motor 21 is driven at a very low rotation, distortion (distortion) occurs in the current waveform, A current exceeding the rating may flow in a transistor (not shown) of the inverter 22.
[0014]
That is, when feedback control based on vector control calculation is performed, if a displacement occurs between the detected magnetic pole position θ and the actual magnetic pole position or the detected magnetic pole position θ changes abruptly, the d-axis current and the q-axis current are changed. Since it cannot be calculated accurately, when the d-axis voltage command value and the q-axis voltage command value are generated, the inverter outputs of the d-axis voltage command value and the q-axis voltage command value as shown in FIG. Distortion occurs in the waveform (in FIG. 4, only the inverter waveform of the d-axis voltage command value is shown). As a result, the current I supplied to the motor 21_U, I_V, I_WSince the current waveform (in FIG. 4, only the current waveform of the current of one phase is shown) is also distorted, the controllability of the motor 21 is degraded.
[0015]
Further, when a current exceeding the rating flows through the transistor, the life of the transistor is shortened, and the durability of the inverter 22 is lowered.
[0016]
The present invention solves the problems of the conventional motor control device and improves the controllability of the motor when the motor is controlled based on the magnetic pole position detected by the simple magnetic pole position detection sensor. An object of the present invention is to provide a motor control device and a motor control method that can increase the durability of an inverter.
[0017]
[Means for Solving the Problems]
Therefore, in the motor control device of the present invention, a current of each phase is generated by turning on and off the motor and the switching element, the current of each phase is supplied to the motor, and the motor is supplied to the motor. Current sensor for detecting the current of each phase to be detected, magnetic pole position detecting means for detecting the position of the magnetic pole, and inverter output for generating an inverter output based on the current command value, the detected current and the detected magnetic pole position Generating means and inverter driving means for driving the inverter according to the inverter output.
[0018]
  The inverter output generating means includes inverter output limiting means for preventing the inverter output from changing suddenly. The inverter output limiting means includes magnetic pole position correcting means for correcting the detected magnetic pole position when the detected change amount of the magnetic pole position exceeds a reference value.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0027]
FIG. 1 is a functional block diagram of the motor control device according to the first embodiment of the present invention.
[0028]
In the figure, 30 is a motor control device, 31 is a motor, 33 and 34 are current sensors for detecting the current of each phase supplied to the motor 31, 43 is a Hall element as magnetic pole position detecting means for detecting the magnetic pole position, Reference numeral 40 includes transistors Tr1 to Tr6 as switching elements. Each of the transistors Tr1 to Tr6 is turned on / off to generate a current of each phase, and the current of each phase is supplied to the motor 31, and 45 is a current command. D-axis voltage command value V as an inverter output based on value, detected current and detected magnetic pole position_d ^*And q-axis voltage command value V_q ^*A motor control unit 51 serving as an inverter output generating means for generating the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*5 is a drive circuit as inverter drive means for driving the inverter 40 according to the above.
[0029]
Then, the motor control unit 45 generates a d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Is provided with a magnetic pole position correcting unit 72 as an inverter output limiting means for preventing a sudden change.
[0030]
FIG. 5 is a schematic diagram of a motor driving device according to the first embodiment of the present invention, FIG. 6 is a schematic diagram of a motor control unit according to the first embodiment of the present invention, and FIG. 7 is a first embodiment of the present invention. FIG. 8 is a time chart showing the operation of the inverter according to the first embodiment of the present invention.
[0031]
In the figure, 10 is a motor drive device, 31 is a motor, and a DC brushless motor is used as the motor 31. The motor 31 is provided with a stator (not shown) formed by winding U-phase, V-phase, and W-phase stator coils 11 to 13 on a stator core (not shown), and is rotatably disposed inside the stator. It consists of a rotor (not shown) with a pair. In order to drive the motor 31 by driving the motor 31, a direct current from the battery 14 is converted into U-phase, V-phase, and W-phase currents I by the inverter 40._U, I_V, I_WAnd the current I of each phase_U, I_V, I_WAre respectively supplied to the stator coils 11 to 13.
[0032]
For this purpose, the inverter 40 includes transistors Tr1 to Tr6 as six switching elements. By selectively turning on / off the transistors Tr1 to Tr6, the current I of each phase_U, I_V, I_WCan be generated.
[0033]
The rotor is provided with a simple magnetic pole position detection sensor, for example, a Hall element 43, and a magnetic pole position detection circuit 44 is connected to the Hall element 43. The sensor outputs S1 to S3 of the Hall element 43 are magnetic pole positions. It is sent to the detection circuit 44. The magnetic pole position detection circuit 44 receives the sensor outputs S1 to S3 from the Hall element 43 to detect the magnetic pole position, and the detected magnetic pole position, that is, the detected magnetic pole position θ is used as a motor as an inverter output generating means. The data is sent to the control unit 45.
[0034]
Therefore, when a command value generation unit of a vehicle control circuit (not shown) that controls the entire electric vehicle generates a current command value and sends the current command value to the motor control unit 45, the motor control unit 45 A pulse width is calculated based on the command value and the detected magnetic pole position θ, and a three-phase pulse width modulation signal S having the pulse width is calculated._U, S_V, S_WAnd the pulse width modulation signal S_U, S_V, S_WIs sent to the drive circuit 51. The drive circuit 51 receives the pulse width modulation signal S_U, S_V, S_WIn response, six drive signals for driving the transistors Tr1 to Tr6 are generated, and the drive signals are sent to the inverter 40. The inverter 40 turns on the transistors Tr1 to Tr6 only while the drive signal is on to turn on the current I_U, I_V, I_WEach current I_U, I_V, I_WIs supplied to each of the stator coils 11-13. In this way, the motor 31 is driven by operating the motor drive device 10 to drive the electric vehicle.
[0035]
By the way, since the stator coils 11 to 13 are star-connected, when the current values of two phases of each phase are determined, the current values of the remaining one phase are also determined. Therefore, the current I of each phase_U, I_V, I_WFor example, the U-phase and V-phase currents I_U, I_VIs detected by the current sensors 33 and 34, and the detection signal SG_U, SG_VIs sent to the motor control unit 45 via the motor current detection circuit 15. Reference numeral 17 denotes a smoothing capacitor. The motor current detection circuit 15, the magnetic pole position detection circuit 44, the motor control unit 45, and the drive circuit 51 constitute a control circuit.
[0036]
Then, feedback control is performed by vector control calculation on a dq axis model in which the d axis is taken in the direction of the magnetic pole pair of the rotor and the q axis is taken in a direction perpendicular to the d axis.
[0037]
For this purpose, the motor control unit 45 detects the detection signal SG sent from the current sensors 33 and 34._U, SG_VThe detected magnetic pole position θ is sent to the UV-dq converter 61. The UV-dq converter 61 detects the detection signal SG._U, SG_VAnd three-phase / two-phase conversion based on the detected magnetic pole position θ, and a detection signal SG_U, SG_VAnd the detected magnetic pole position θ with the d-axis current i_dAnd q-axis current i_qConvert to
[0038]
And d-axis current i_dIs sent to the subtractor 62, where the d-axis current i_dAnd d-axis current command value i of the current command values_dsD-axis current deviation Δi_dIs calculated, and the d-axis current deviation Δi_dIs sent to a d-axis voltage command value generating unit 64 as voltage command value generating means. On the other hand, q-axis current i_qIs sent to the subtractor 63, where the q-axis current i_qQ-axis current command value i of the current command values_qsQ-axis current deviation Δi_qIs calculated, and the q-axis current deviation Δi_qIs sent to the q-axis voltage command value generating unit 65 as voltage command value generating means.
[0039]
The d-axis voltage command value generator 64 and the q-axis voltage command value generator 65 are connected to the q-axis inductance L sent from the parameter calculator 71._qAnd d-axis inductance L_dAnd the d-axis current deviation Δi_dAnd q-axis current deviation Δi_qD-axis current deviation Δi_dAnd q-axis current deviation Δi_qD-axis voltage command value V as the inverter output on the two axes so that becomes zero_d ^*And q-axis voltage command value V_q ^*And d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Are sent to the dq-UV converter 67, respectively.
[0040]
Subsequently, the dq-UV converter 67 receives the d-axis voltage command value V_d ^*Q-axis voltage command value V_q ^*And two-phase / three-phase conversion based on the detected magnetic pole position θ, and the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*The voltage command value V for each phase_U ^*, V_V ^*, V_W ^*And the voltage command value V_U ^*, V_V ^*, V_W ^*To the PWM generator 68. The PWM generator 68 generates a voltage command value V for each phase._U ^*, V_V ^*, V_W ^*And a pulse width modulation signal S for each phase based on a DC voltage detected by a DC voltage detection circuit (not shown)._U, S_V, S_WIs generated.
[0041]
By the way, in the Hall element 43, since the resolution is low, the detection accuracy of the magnetic pole position is lowered accordingly, and a positional deviation occurs between the detected magnetic pole position θ and the actual magnetic pole position. Further, the detected magnetic pole position θ changes in a step shape every 60 ° in electrical angle.
[0042]
Therefore, when the detected magnetic pole position θ is directly sent to the UV-dq converter 61 and the motor 31 is driven at a very low rotation, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*The inverter output waveform will be distorted. As a result, the current I supplied to the motor 31_U, I_V, I_WAs a result, distortion occurs in the current waveform, and the controllability of the motor 31 decreases. Further, when a current exceeding the rating flows in the transistors Tr1 to Tr6 in the inverter 40, the lifetime of the transistors Tr1 to Tr6 is shortened, and the durability of the inverter 40 is lowered.
[0043]
Therefore, even if a positional deviation occurs between the detected magnetic pole position θ and the actual magnetic pole position or the detected magnetic pole position θ changes suddenly, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Inverter output waveform and current I_U, I_V, I_WThe motor control unit 45 is provided with a magnetic pole position correction unit 72 as an inverter output limiting unit so that the current waveform of the motor can be suppressed from being distorted. θ is corrected, and d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*To prevent sudden changes.
[0044]
For this purpose, a change amount calculation unit (not shown) of the magnetic pole position correction unit 72 reads the detected magnetic pole position θ and calculates a change amount (slope) Δθ per unit time of the detected magnetic pole position θ. Then, the magnetic pole position correcting means as the first correcting means (not shown) of the magnetic pole position correcting unit 72 compares the calculated change amount Δθ with the reference value, and the calculated change amount Δθ exceeds the reference value. In some cases, the detected magnetic pole position θ is corrected to limit the variation Δθ so as not to exceed the reference value. In FIG. 7, the detected magnetic pole position θ before correction is indicated by a broken line, and the detected magnetic pole position θ after correction is indicated by a solid line. Further, when the corrected magnetic pole position θ is generated, a minute position is added at each control timing in order to set the variation Δθ to a predetermined value.
[0045]
In this way, the detected magnetic pole position θ is corrected so that the change amount Δθ does not exceed the reference value._dAnd q-axis current i_qAnd d-axis current deviation Δi_dAnd q-axis current deviation Δi_qNone of these changes abruptly. Therefore, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*As shown in FIG. 8, the inverter output waveform (in FIG. 8, the d-axis voltage command value V_d ^*Only the waveform is shown. ) Can be prevented from being distorted. As a result, the current I supplied to the motor 31_U, I_V, I_WCurrent waveform (in FIG. 8, U-phase current I_UOnly the current waveform is shown. ) Can be prevented from being distorted, so that the controllability of the motor 31 can be improved.
[0046]
And since it can prevent that the electric current exceeding a rating flows into the said transistors Tr1-Tr6, the lifetime of the transistors Tr1-Tr6 can be lengthened, and durability of the inverter 40 can be made high.
[0047]
In addition, even if a positional deviation occurs between the detected magnetic pole position θ and the actual magnetic pole position, the detected magnetic pole position θ is corrected and gradually changes._U, I_V, I_WThe distortion of the current waveform can be suppressed.
[0048]
Next, a second embodiment of the present invention will be described.
[0049]
FIG. 9 is a waveform diagram of the detected magnetic pole position in the second embodiment of the present invention.
[0050]
By the way, when the motor 31 (FIG. 1) is driven at a very low rotation and the motor rotation speed is lower than the set value, the detection accuracy of the Hall element 43 as the magnetic pole position detection means varies, so that the detected magnetic pole position is continuously detected. θ cannot be obtained. On the other hand, when the motor rotation speed exceeds the set value, the detected magnetic pole position θ can be obtained relatively continuously. In this case, if the detected magnetic pole position θ is estimated by interpolation, the positional deviation between the detected magnetic pole position θ and the actual magnetic pole position can be reduced.
[0051]
Therefore, when the motor rotation speed of the motor 31 is detected by a motor rotation speed sensor (not shown) and the motor rotation speed is lower than the set value, the magnetic pole position correction unit 72 as the inverter output limiting means detects the detected magnetic pole position in the first correction mode. θ is corrected. For this purpose, the change amount calculation means (not shown) of the magnetic pole position correction unit 72 reads the detected magnetic pole position θ, calculates the change amount Δθ per unit time of the detected magnetic pole position θ, and the magnetic pole position correction unit 72 The magnetic pole position correcting means as the first correcting means compares the calculated change Δθ with a reference value, and corrects the detected magnetic pole position θ when the calculated change Δθ exceeds the reference value. The amount of change Δθ is limited so as not to exceed the reference value.
[0052]
When the motor rotation speed exceeds the set value, the magnetic pole position correction unit 72 corrects the detected magnetic pole position θ in the second correction mode. For this purpose, the interpolation means (not shown) of the magnetic pole position correction unit 72 interpolates the detected magnetic pole position θ before being corrected in the second correction mode, and prevents the detected magnetic pole position θ from changing suddenly. In the present embodiment, linear interpolation is performed as the interpolation.
[0053]
In FIG. 9, the detected magnetic pole position θ before correction is a broken line, the detected magnetic pole position θ after correction in the first correction mode is a solid line, and detection after correction in the second correction mode. The magnetic pole position θ is indicated by a one-dot chain line.
[0054]
Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol.
[0055]
FIG. 10 is a schematic diagram of a motor control unit according to the third embodiment of the present invention, and FIG. 11 is a time chart showing the operation of the inverter according to the third embodiment of the present invention.
[0056]
In this case, the first axis voltage command value correcting unit 73 is connected between the d-axis voltage command value generating unit 64 serving as the voltage command value generating unit and the dq-UV converter 67, and the q-axis serving as the voltage command value generating unit. A second shaft voltage command value correction unit 74 is disposed between the voltage command value generation unit 65 and the dq-UV converter 67, and the first and second shaft voltage command value correction units 73 and 74 are Is also composed of a limiter and constitutes an inverter output limiting means. Inverter output correction means as second correction means (not shown) of the first and second shaft voltage command value correction units 73 and 74 are a d-axis voltage command value generation unit 64 and a q-axis voltage command value generation unit 65. D-axis voltage command value V as inverter output respectively generated by_d ^*And q-axis voltage command value V_q ^*D-axis voltage command value V when each exceeds a threshold value set larger by a predetermined amount._d ^*And q-axis voltage command value V_q ^*Is corrected so as not to exceed the threshold.
[0057]
Thus, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Is corrected so that the threshold value is not exceeded, so the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Can be prevented from changing suddenly, and as shown in FIG. 11, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Inverter output waveform (in FIG. 11, d-axis voltage command value V_d ^*Only the waveform is shown. ) Can be prevented from being distorted. As a result, the current I supplied to the motor 31 (FIG. 5)_U, I_V, I_WCurrent waveform (in FIG. 11, U-phase current I_UOnly the current waveform is shown. ) Can be prevented from being distorted, so that the controllability of the motor 31 can be improved.
[0058]
In FIG. 11, the d-axis voltage command value V before correction_d ^*Is a broken line, d-axis voltage command value V after correction_d ^*Is indicated by a solid line.
[0059]
And since it can prevent that the electric current exceeding a rating flows into transistor Tr1-Tr6 as a switching element, the lifetime of transistors Tr1-Tr6 can be lengthened and durability of the inverter 40 can be made high. .
[0060]
By the way, when the motor 31 is driven, a counter electromotive voltage is generated. The counter electromotive voltage increases as the motor rotation speed increases._d ^*And q-axis voltage command value V_q ^*Need to be high. Therefore, d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*It is preferable to change the threshold value corresponding to the motor rotation speed. In this case, the d-axis voltage command type V_d ^*And q-axis voltage command value V_q ^*As the value increases, the maximum value of the inverter output waveform also increases.
[0061]
Next, a fourth embodiment of the present invention will be described.
[0062]
FIG. 12 is a diagram showing a threshold map according to the fourth embodiment of the present invention. In the figure, the horizontal axis represents the motor speed, and the vertical axis represents the threshold value V._refIs adopted.
[0063]
In the figure, V_RIs the counter electromotive voltage generated when the motor 31 (FIG. 5) is driven, V_refIs the d-axis voltage command value V as the inverter output_d ^*(Fig. 10) and q-axis voltage command value V_q ^*Is the threshold value. The back electromotive voltage V_RIs proportional to the motor speed and increases as the motor speed increases._refCorresponds to the motor speed, that is, the back electromotive force V_RIt can be changed according to.
[0064]
Therefore, even if the motor speed changes, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*It is possible to reliably suppress the occurrence of distortion in the inverter output waveform. As a result, the current I supplied to the motor 31_U, I_V, I_WSince the distortion of the current waveform can be reliably suppressed, the controllability of the motor 31 can be further improved.
[0065]
And since it can prevent reliably that the electric current exceeding a rating flows into transistor Tr1-Tr6 as a switching element, the lifetime of transistors Tr1-Tr6 can be lengthened, and durability of the inverter 40 is made still higher. be able to.
[0066]
By the way, the d-axis voltage command value generation unit 64 receives the q-axis inductance L sent from the parameter calculation unit 71._qAnd d-axis current deviation Δi_dD-axis voltage command value V based on_d ^*The q-axis voltage command value generation unit 65 generates the d-axis inductance L sent from the parameter calculation unit 71._dAnd q-axis current deviation Δi_qQ-axis voltage command value V based on_q ^*Is supposed to be generated. Usually, the d-axis inductance L_dAnd q-axis inductance L_qIs the d-axis current deviation Δi_dAnd q-axis current deviation Δi_qIs set to be 0 and within a certain limit range (adjustment allowable range) even if the motor speed changes.
[0067]
FIG. 13 is a diagram showing the limit ranges of d-axis inductance and q-axis inductance in a normal motor control circuit. In the figure, the horizontal axis represents the motor speed, and the vertical axis represents the d-axis inductance L._dAnd q-axis inductance L_qIs adopted.
[0068]
In the figure, ARL_dIs the d-axis inductance L_dLimit range of (Fig. 10), ARL_qIs the q-axis inductance L_qThis is the limit range. In this case, even if the motor speed changes, the limit range ARL_d, ARL_qIs made constant.
[0069]
However, when the motor speed increases, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*As a result, the inverter output waveform is distorted.
[0070]
Therefore, in the region where the motor speed is high, the limit range ARL_d, ARL_qA fifth embodiment in which the width is narrowed will be described.
[0071]
FIG. 14 is a diagram showing the limit range of the d-axis inductance in the fifth embodiment of the present invention, and FIG. 15 is a diagram showing the limit range of the q-axis inductance in the fifth embodiment of the present invention. In FIG. 14, the horizontal axis represents the motor speed, and the vertical axis represents the d-axis inductance L._d15, the horizontal axis represents the motor rotation speed, and the vertical axis represents the q-axis inductance L._qIs adopted.
[0072]
In the figure, ARL_dIs the d-axis inductance L_dLimit range, ARL_qIs the q-axis inductance L_qThis is the limit range. In this case, when the motor driving state changes, for example, when the motor rotation speed increases, the parameter calculation unit 71 (FIG. 10) serving as the inverter output limiting means has a limit range ARL._d, ARL_qLower the maximum allowable value.
[0073]
Therefore, even if the motor speed changes, the d-axis voltage command value V as the inverter output_d ^*And q-axis voltage command value V_q ^*Can be prevented from abruptly changing, so that distortion of the inverter output waveform can be reliably suppressed. As a result, the current I supplied to the motor 31 (FIG. 5)_U, I_V, I_WSince the distortion of the current waveform can be reliably suppressed, the controllability of the motor 31 can be further improved.
[0074]
And since it can prevent reliably that the electric current exceeding a rating flows into transistor Tr1-Tr6 as a switching element, the lifetime of transistors Tr1-Tr6 can be lengthened, and durability of the inverter 40 is made still higher. be able to.
[0075]
In the present embodiment, the limit range ARL is made corresponding to the motor rotation speed._d, ARL_qIs changed, but limited range ARL corresponding to power running or regeneration_d, ARL_qCan also be changed.
[0076]
By the way, since the motor 31 is controlled at a constant control timing, that is, every fixed period, if the motor rotation speed increases, the control of the motor 31 cannot follow the rotation. As a result, the d-axis voltage command value V_d ^*And q-axis voltage command value V_q ^*Cannot be calculated accurately. Therefore, the motor speed is the threshold value N._SWhen the value exceeds the limit range ARL, the parameter calculation unit 71_d, ARL_qTo narrow.
[0077]
Therefore, it is possible to reliably suppress distortion in the inverter output waveform when the motor 31 is driven at high speed.
[0078]
In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.
[0079]
【The invention's effect】
As described above in detail, according to the present invention, in the motor control device, current of each phase is generated by turning on and off the motor and the switching element, and the current of each phase is supplied to the motor. Based on the current command value, the detected current, and the detected position of the magnetic pole, the inverter for detecting the current of each phase supplied to the motor, the magnetic pole position detecting means for detecting the position of the magnetic pole, Inverter output generating means for generating an inverter output, and inverter driving means for driving the inverter according to the inverter output.
[0080]
  The inverter output generating means includes inverter output limiting means for preventing the inverter output from changing suddenly. The inverter output limiting means includes magnetic pole position correcting means for correcting the detected magnetic pole position when the detected change amount of the magnetic pole position exceeds a reference value.
[0081]
In this case, since the inverter output does not change abruptly, distortion in the inverter output waveform can be suppressed. As a result, it is possible to suppress distortion in the current waveform of the current supplied to the motor, so that the controllability of the motor can be improved.
[0082]
And since it can prevent that the electric current exceeding a rating flows into a switching element, the lifetime of a switching element can be lengthened and durability of an inverter can be made high.
[0084]
  Furthermore, the detected position of the magnetic pole is corrected, and the amount of change in the detected position of the magnetic pole can be prevented from exceeding the reference value. Therefore, the inverter output is prevented from changing abruptly.
[0085]
Even if a positional deviation occurs between the detected magnetic pole position and the actual magnetic pole position, the detected magnetic pole position is corrected and gradually changed, so that the current waveform of the current is distorted by the positional deviation. Generation | occurrence | production can be suppressed.
[Brief description of the drawings]
FIG. 1 is a functional block diagram of a motor control device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a conventional motor control device.
FIG. 3 is a waveform diagram of sensor output and detection magnetic pole position of a conventional Hall element.
FIG. 4 is a time chart showing the operation of a conventional inverter.
FIG. 5 is a schematic view of a smoke driving device according to the first embodiment of the present invention.
FIG. 6 is a schematic diagram of a motor control unit according to the first embodiment of the present invention.
FIG. 7 is a waveform diagram of a detected magnetic pole position in the first embodiment of the present invention.
FIG. 8 is a time chart showing the operation of the inverter in the first embodiment of the present invention.
FIG. 9 is a waveform diagram of a detected magnetic pole position in the second embodiment of the present invention.
FIG. 10 is a schematic diagram of a motor control unit according to a third embodiment of the present invention.
FIG. 11 is a time chart showing the operation of the inverter according to the third embodiment of the present invention.
FIG. 12 is a diagram showing a threshold map in the fourth embodiment of the present invention.
FIG. 13 is a diagram showing a limit range of d-axis inductance and q-axis inductance in a normal motor control circuit.
FIG. 14 is a diagram showing a limit range of d-axis inductance in the fifth embodiment of the present invention.
FIG. 15 is a diagram showing a limit range of q-axis inductance in the fifth embodiment of the present invention.
[Explanation of symbols]
30 Motor drive device
31 motor
33, 34 Current sensor
40 inverter
43 Hall element
45 Motor controller
51 Drive circuit
71 Parameter calculator
72 Magnetic pole position correction unit
73, 74 First and second shaft voltage command value correction units
ARL_d, ARL_q    Limit range
I_U, I_V, I_W    Current
i_ds, I_qs    d-axis current command value, q-axis current command value
L_d, L_q    d-axis inductance, q-axis inductance
N_S, V_ref    Threshold
Tr1 to Tr6 transistors
V_d ^*, V_q ^*    d-axis voltage command value, q-axis voltage command value
θ Detection magnetic pole position

Claims (6)

A motor, an inverter that generates a current of each phase by turning on and off the switching element, and supplies the current of each phase to the motor; and a current sensor that detects a current of each phase supplied to the motor; Magnetic pole position detecting means for detecting the position of the magnetic pole, inverter output generating means for generating an inverter output based on the current command value, the detected current and the detected magnetic pole position, and driving the inverter according to the inverter output The inverter output generating means includes inverter output limiting means for preventing the inverter output from changing suddenly , and the inverter output limiting means includes a detected change amount of the magnetic pole position. JP but when it exceeds the reference value, the Rukoto includes a magnetic pole position correction means for correcting the position of the detected magnetic pole Motor controller according to. Before Symbol inverter output limiting means comprises Interpolation means, when the motor rotational speed is below the set value, to correct the position of the test out magnetic pole by the magnetic pole position correction means, the setting motor speed If it exceeds the value, the motor control device according to claim 1 for interpolating a position of inspection issued pole by the interpolation means.   2. The motor control device according to claim 1, wherein the inverter output limiting unit includes an inverter output correcting unit that corrects the inverter output when the inverter output exceeds a threshold that is set larger by a predetermined amount.   The motor control device according to claim 1, wherein the inverter output limiting unit changes a limit range of the d-axis inductance and the q-axis inductance in accordance with a driving state of the motor. The motor control device according to claim 4 , wherein the limit range is narrowed when the motor rotation speed exceeds a threshold value. Each phase current is generated by turning on and off the switching element, the current of each phase is supplied to the motor, the current of each phase supplied to the motor is detected, the position of the magnetic pole is detected, When an inverter output is generated based on the command value, the detected current and the detected magnetic pole position, the inverter is driven according to the inverter output, and the detected change amount of the magnetic pole position exceeds a reference value A motor control method characterized in that the inverter output is prevented from changing suddenly by correcting the position of the detected magnetic pole .

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