WO2024070731A1 - Motor control device - Google Patents

Motor control device Download PDF

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Publication number
WO2024070731A1
WO2024070731A1 PCT/JP2023/033547 JP2023033547W WO2024070731A1 WO 2024070731 A1 WO2024070731 A1 WO 2024070731A1 JP 2023033547 W JP2023033547 W JP 2023033547W WO 2024070731 A1 WO2024070731 A1 WO 2024070731A1
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WIPO (PCT)
Prior art keywords
motor
current
control device
phase
correction amount
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PCT/JP2023/033547
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French (fr)
Japanese (ja)
Inventor
広大 武田
峻 谷口
健太郎 松尾
渉 初瀬
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日立Astemo株式会社
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Publication of WO2024070731A1 publication Critical patent/WO2024070731A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/05—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation specially adapted for damping motor oscillations, e.g. for reducing hunting
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
    • H02P23/04—Arrangements or methods for the control of AC motors characterised by a control method other than vector control specially adapted for damping motor oscillations, e.g. for reducing hunting
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
    • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
    • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters

Definitions

  • the present invention relates to a motor control device that controls the torque and speed of a motor.
  • the motor control device controls the motor current so that the motor torque and speed follow the command values. At this time, torque ripple occurs due to time harmonics of the motor current and spatial harmonics of the motor magnetic flux. Torque ripple is a cause of vibration and noise. In order to reduce the torque ripple, the motor control device executes torque ripple suppression control. In torque ripple suppression control, the current command value is corrected according to the torque ripple estimate value.
  • Torque ripple can also occur due to a gain error in the current sensor. If there is a gain error in the current sensor, a secondary vibration component occurs in the dq axis current converted from the motor current detection value (see, for example, "Equation (2)" in Patent Document 1 described below). The motor control device executes current control to remove this vibration component. This causes a current ripple in the motor current, which in turn generates a torque ripple.
  • Patent Document 1 The technology described in Patent Document 1 is known as a conventional technology for estimating and correcting the gain error of such a current sensor.
  • the motor control device has two operating modes: a normal operating mode and a CT correction drive mode.
  • the CT correction drive mode in the current control section, the d-axis current control section and the q-axis current control section are stopped, and only the non-interference control section continues to operate.
  • either the d-axis current command value Id* or the q-axis current command value Iq* is set to zero, and current flows only in one of the d and q axes.
  • only the pulsating component contained in either the d-axis current detection value or the q-axis current detection value is extracted to calculate the CT gain error.
  • the gain in the three-phase current calculation section is corrected based on the calculated CT gain error.
  • the motor control device has an operating sequence in which it starts up in a normal operating mode, goes through a CT correction drive mode, and then returns to the normal operating mode.
  • the motor control device is equipped with a special operation sequence to estimate and correct the gain error of the current sensor. This means that the development time and development costs of the motor control device may increase due to the need to set sequence execution conditions and stabilize control when switching sequences.
  • the present invention provides a motor control device that can stably and accurately estimate and compensate for the gain error of a current sensor without requiring a special operating sequence.
  • the motor control device generates a control signal for an inverter that drives an AC motor, and includes an error calculation unit that calculates the gain error of the current sensor using the amplitude value of the three-phase motor current detected by the current sensor, and a correction amount calculation unit that calculates a current correction amount to compensate for the gain error based on the gain error estimated by the error calculation unit.
  • FIG. 1 is a functional block diagram illustrating a configuration of a motor control device according to a first embodiment.
  • FIG. 4 is a functional block diagram illustrating a configuration of an error calculation unit in the first embodiment.
  • FIG. 4 is a functional block diagram illustrating a configuration of a correction amount calculation unit in the first embodiment.
  • 10 is a state transition diagram showing a change in the operation of the error estimating unit 102.
  • FIG. 4 is a flowchart showing an operation of a motor state determination unit 103.
  • 10 is a flowchart showing an operation of a correction destination selection unit 203.
  • FIG. 11 is a functional block diagram showing a configuration of a motor control device according to a second embodiment.
  • FIG. 11 is a functional block diagram illustrating a configuration of an error calculation unit in the second embodiment.
  • FIG. 11 is a functional block diagram illustrating a configuration of a correction amount calculation unit in the second embodiment.
  • 10 is a flowchart showing the operation of a correction destination selection unit
  • FIG. 1 is a functional block diagram showing the configuration of a motor control device according to a first embodiment of the present invention.
  • dq axis refers to the "d axis and q axis.”
  • X such as “i”
  • X dq refers to a “vector quantity (X d , X q )
  • X uvw refers to a “vector quantity (X u , X v , X w ).
  • uvw refers to three phases of AC, that is, "U phase, V phase, and W phase.”
  • the motor control device 1 controls the speed and torque of the motor 5 by controlling the switching of the inverter 4 that supplies AC power to the motor 5.
  • the motor control device 1 is configured with a processing device such as a microcomputer, and functions as each part by executing a specific program.
  • the inverter 4 is a three-phase inverter whose main circuit is a three-phase full-bridge circuit composed of semiconductor switching elements such as IGBTs and MOSFETs.
  • the control signal D* uvw generated by the motor control device 1 controls the on/off of the semiconductor switching elements that constitute the main circuit of the inverter 4.
  • the inverter 4 converts DC power input from a DC power source such as a storage battery into three-phase AC power and outputs a three-phase AC voltage v uvw .
  • the control signal D* uvw is a gate control signal for the semiconductor switching elements when the semiconductor switching elements are IGBTs or MOSFETs.
  • the control signal D* uvw is composed of six control signals, namely, a control signal for the U-phase upper arm (D* up ), a control signal for the U-phase lower arm (D* un ), a control signal for the V-phase upper arm (D* vp ), a control signal for the V-phase lower arm (D* vn ), a control signal for the W-phase upper arm (D* wp ) and a control signal for the W-phase lower arm (D* wn ), in order to control the switching of the three-phase full-bridge circuit which is the main circuit of the inverter 4.
  • the subscripts p and n represent the upper arm and lower arm, respectively.
  • the motor 5 is a three-phase AC synchronous motor, which is a rotating machine, such as a permanent magnet synchronous motor.
  • the motor 5 is not limited to a synchronous machine, and an induction machine may be used.
  • the motor 5 is not limited to a rotating machine, and a linear motor may be used.
  • the motor 5 may have a power generation function.
  • the motor control device 1 includes a dq-axis current command value 2 (i* dq ), a controller 3, an electrical angle calculation unit 6, an electrical angular velocity calculation unit 7, an A/D converter 8, a three-phase/dq-axis converter 9, a dq-axis current correction unit 10a, a three-phase current correction unit 10b, a current sensor 11, an error calculation unit 100, and a correction amount calculation unit 200.
  • the controller 3 generates a control signal D uvw * for controlling the switching of the inverter 4 in accordance with the difference between the dq-axis current detection value i dq and the dq-axis current command value i* dq (2) so that i dq coincides with i * dq .
  • the dq-axis current correction unit 10a corrects the difference input to the controller 3 by a dq-axis current correction amount ⁇ i dq .
  • ⁇ i dq is the correction amount of i dq , and compensates for the generation of vibration components of the dq-axis current detection value i dq caused by the gain error of the current sensor 11, as will be described later.
  • the controller 3 has a known configuration.
  • the controller 3 is composed of a dq-axis current controller that creates dq-axis voltage command values by PI calculation, a dq/three-phase converter that converts the dq-axis voltage command values into three-phase voltage command values, and a PWM controller that generates inverter control signals according to the three-phase voltage command values.
  • the dq-axis voltage command values may be created using known voltage equations.
  • the electrical angle calculation unit 6 calculates and outputs the electrical angle ⁇ e based on a rotational position signal from a rotation sensor (not shown) provided in the motor 5.
  • Resolvers Hall sensors, rotary encoders, etc. can be used as rotation sensors.
  • the electrical angular velocity calculation unit 7 calculates and outputs the electrical angular velocity ⁇ e based on a rotational position signal from a rotation sensor (not shown) provided in the motor 5.
  • the electrical angular velocity calculation unit 7 may be configured by a differentiator that differentiates ⁇ e output from the electrical angle calculation unit 6 to calculate ⁇ e .
  • the A/D converter 8 converts the current detection signal of the current sensor 11, obtained when the current sensor 11 acquires the three-phase motor actual current value i real uvw flowing in the distribution cable between the output of the inverter 4 and the motor 5, into a digital value handled by the motor control device 1, and outputs it as the three-phase motor current detection value i meas uvw .
  • the three-phase/dq-axis converter 9 calculates the dq-axis current detection value i dq based on the three-phase motor current detection value i meas uvw from the A/D converter 8 and the electrical angle ⁇ e from the electrical angle calculation unit 6.
  • the three-phase current correction unit 10b corrects i meas uvw by a correction coefficient m uvw described later.
  • the corrected three-phase motor current detection value is input to the three-phase/dq-axis converter 9.
  • the correction coefficient m uvw compensates for the generation of vibration components in the dq-axis current detection value i dq caused by a gain error (hereinafter referred to as "error") of the current sensor 11.
  • Current sensors 11 are provided on each of the three-phase distribution cables, or on two of the three-phase distribution cables.
  • A/D converter 8 converts the detection signals for the two phases into digital values, which are used as motor current detection values for the two phases.
  • a calculator (adder/subtractor) (not shown) calculates the motor current value for the remaining phase.
  • CT current transformer
  • Hall element a Hall element
  • the error calculation unit 100 calculates the error err uvw of the current sensor 11 based on the three-phase motor current detection value imeas uvw , the electrical angle ⁇ e , the electrical angular velocity ⁇ e , and the dq-axis current command value i dq *.
  • the correction amount calculation unit 200 calculates the dq-axis current correction amount ⁇ i dq used in the dq-axis current correction unit 10a and the correction coefficient m uvw used in the three-phase current correction unit 10b, based on the err uvw calculated by the error calculation unit 100 and the dq-axis current command value i* dq .
  • FIG. 2 is a functional block diagram showing the configuration of the error calculation unit 100 (FIG. 1) in the first embodiment.
  • the error calculation unit 100 includes a three-phase current amplitude estimation unit 101, an error estimation unit 102, and a motor state determination unit 103.
  • the subscripts “UVW” represent the three phases of AC, i.e., “U phase, V phase, and W phase.”
  • the motor state determination unit 103 determines the state of the motor 5 (FIG. 1) based on the dq axis current command values i* dq .
  • the error estimation unit 102 calculates and estimates the error err uvw of the current sensor 11 ( FIG. 1 ) based on the three-phase motor current amplitude values I UVW estimated by the three-phase current amplitude estimation unit 101 in accordance with the state of the motor 5 determined by the motor state determination unit 103.
  • FIG. 3 is a functional block diagram showing the configuration of the correction amount calculation unit 200 (FIG. 1) in the first embodiment.
  • the correction amount calculation unit 200 includes a dq-axis current correction amount calculation unit 201, a three-phase current correction amount calculation unit 202, and a correction destination selection unit 203.
  • the correction destination selection unit 203 selects, from ⁇ i dq and m uvw , a correction amount used to compensate for the occurrence of vibration components in the dq-axis current detection value i dq caused by the error of the current sensor 11. That is, the correction destination selection unit 203 selects, from the dq-axis current correction amount calculation unit 201 and the three-phase current correction amount calculation unit 202, a correction amount calculation unit that executes calculation of the correction amount.
  • the dq-axis current detection value i dq is expressed by the formula (1).
  • i dq is expressed as a column vector.
  • the column vector in the first term on the right side represents i real dq obtained by coordinate transformation of i real uvw .
  • the phase ⁇ in the second and third terms on the right side is a constant phase amount, as described later (see equation (12)).
  • the three-phase current correction unit 10b (FIG. 1) corrects the three-phase motor current detection values i meas uvw based on the equation (2).
  • the three-phase/dq-axis converter 9 calculates the dq-axis current detection value i dq from the corrected three-phase motor current detection value i meas uvw ′ and the electrical angle ⁇ e according to equation (3).
  • the controller 3 uses such dq-axis current detection values i_dq to generate the control signal D* uvw for controlling the switching of the inverter 4 (FIG. 1) as described above.
  • the means for estimating the three-phase motor current amplitude values IUVW in the three-phase current amplitude estimator 101 will be described using the U-phase motor current amplitude value IU as an example.
  • the U-phase motor current detection value i_meas u and the U-phase motor current amplitude value IU have the relationship shown in Equation (4).
  • the electrical angle ⁇ e may be corrected to be advanced by ⁇ e ⁇ t.
  • ⁇ c in equations (4) and (5) is a current phase in a rotating coordinate system and can be calculated from the dq-axis current detection values i dq . In this embodiment, however, it is calculated from the dq-axis current command values i* dq using equation (6).
  • ⁇ c may be calculated based on i* dq that has been passed through a low-pass filter (LPF) equivalent to a current control response expressed as a frequency.
  • LPF low-pass filter
  • table data representing the correspondence between ⁇ c and i dq may be used.
  • V-phase and W-phase motor current amplitude values I V and I W are expressed by equations (7) and (8) with phases shifted by ⁇ 2/3 ⁇ and 2/3 ⁇ , respectively, from the phase reference.
  • the denominators of equations (6) to (8) are trigonometric functions, a state of division by zero or very close to zero occurs twice per electrical angle cycle. Because the actual three-phase motor current is distorted from a sine wave, the current amplitude value may fluctuate significantly near the current zero crossing. This may reduce the accuracy of the error calculation in the error estimation unit 102. For this reason, when the value of the trigonometric function in the denominator falls below a certain value, the three-phase current amplitude estimation unit 101 may stop the calculation operation and output a predetermined value that is set in advance.
  • the error estimation unit 102 changes its operation based on the output (determination result) of the motor state determination unit 103.
  • FIG. 4 is a state transition diagram showing changes in the operation of the error estimation unit 102.
  • the initial value is (1, 1, 1).
  • the error may be set as the initial value.
  • the error estimation unit 102 calculates and outputs the error based on equation (9).
  • FIG. 5 is a flowchart showing the operation of the motor state determination unit 103.
  • step S101 When the motor state determination unit 103 starts processing (step S101), it determines in step S102 whether the time rate of change of the current phase amount ⁇ c of the motor 5, expressed by equation (6), is equal to or less than a predetermined constant value. If the motor state determination unit 103 determines that it is equal to or less than the constant value (YES in step S102), it then executes step S103, and if it determines that it is not equal to or less than the constant value, i.e., that it is greater than the constant value (NO in step S102), it then executes step S105.
  • step S103 the motor state determination unit 103 determines whether to perform error estimation. If the motor state determination unit 103 determines that an error estimation should be performed (YES in step S103), it next executes step S104, and if it determines that an error estimation should not be performed (NO in step S103), it next executes step S105.
  • step S104 the motor state determination unit 103 outputs "error estimation possible" as the motor state determination result. After executing step S104, the motor state determination unit 103 ends the series of processes.
  • step S105 the motor state determination unit 103 outputs "error estimation not possible" as the motor state determination result. After executing step S105, the motor state determination unit 103 ends the series of processes.
  • step S103 The criteria in step S103 are set appropriately, taking into account cases where the error estimation accuracy decreases or the calculation load increases.
  • step S103 may be omitted.
  • the error calculation includes division by the current amplitude value, so if the current amplitude value is small, the accuracy of the error calculation may decrease.
  • a conditional branch may be added to the operation of the motor state determination unit 103 so that "error estimation cannot be performed" is output when the current amplitude value is equal to or less than a predetermined constant value.
  • the second-order vibration component in the dq-axis current detection value i dq as shown in the third term on the right side of equation (1) is compensated for. Note that in this embodiment, the occurrence of the DC component of the dq-axis current as shown in the second term on the right side of equation (1) is not compensated for. Therefore, it is possible to suppress an unexpected decrease in torque accuracy due to compensation for the DC component.
  • the correction amount may be gradually adjusted according to the rotation speed of the motor 5.
  • the three-phase current correction amount calculation unit 202 calculates a correction coefficient m uvw based on the equation (14) using err uvw .
  • the correction of the three-phase motor current detection values using m uvw requires less calculation and has a smaller calculation load than the correction of the dq axis currents using ⁇ i dq .
  • the correction destination selection unit 203 selects the amount of correction to be calculated using the error err uvw from among m uvw and ⁇ i dq according to the conditions. That is, the correction destination selection unit 203 selects either the correction of the three-phase motor current detection value imeas uvw using the calculated m uvw or the correction of the dq-axis current detection value using the calculated ⁇ i dq . Note that if either one of them is selected in advance, the correction destination selection unit 203 may be omitted.
  • FIG. 6 is a flowchart showing the operation of the correction destination selection unit 203.
  • step S201 When the correction destination selection unit 203 starts processing (step S201), it determines in step S202 whether to perform error correction. If the correction destination selection unit 203 determines that error correction is to be performed (YES in step S202), it then executes step S204, and if it determines that error correction is not to be performed (NO in step S202), it then executes step S203.
  • step S204 the correction destination selection unit 203 determines whether to perform error correction on the d- and q-axis currents. If the correction destination selection unit 203 determines that error correction is to be performed on the d- and q-axis currents (YES in step S204), it next executes step S205, and if it determines that error correction is not to be performed on the d- and q-axis currents (NO in step S203), it next executes step S206.
  • step S203 the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to output "0" (vector amount) as ⁇ i dq , and instructs the three-phase current correction amount calculation unit 202 to output "1" (vector amount) as m uvw .
  • step S207 the correction destination selection unit 203 ends the series of processes.
  • step S205 the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to calculate and output ⁇ i dq using the error err uvw , and instructs the three-phase current correction amount calculation unit 202 to output "1" (vector amount) as m uvw .
  • step S207 the correction destination selection unit 203 ends the series of processes.
  • step S206 the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to output "0" (vector amount) as ⁇ i dq , and instructs the three-phase current correction amount calculation unit 202 to calculate and output m uvw using err uvw .
  • step S207 the correction destination selection unit 203 ends the series of processes.
  • error correction is performed on only one of the three-phase currents and the d- and q-axis currents. This improves the stability of the error correction operation in the motor control device.
  • step S204 The criteria in step S204 are set appropriately, taking into consideration cases where the error estimation accuracy decreases or the calculation load increases. Depending on the criteria in step S204, error correction may be performed on both the three-phase currents and the d- and q-axis currents.
  • the gain error of the current sensor is calculated based on the three-phase AC current amplitude value, and one of the three-phase current detection values and the dq-axis current detection values is corrected based on the calculated gain error.
  • the offset error of the current sensor has been compensated for in advance.
  • the offset error compensation of the current sensor can be performed, for example, by subtracting the average current value indicated by the output signal of the current sensor when no motor current is flowing from the motor current detection value.
  • the control unit for compensating for the gain error of the current sensor 11 is divided into an error calculation unit 100 that performs error estimation, and a correction amount calculation unit 200 that performs error correction.
  • the error calculation unit 100 may be operated to perform error estimation, and then the correction amount calculation unit 200 may be operated to perform error correction.
  • the correction amount calculation unit 200 may be operated to perform error correction based on the estimated error. Note that error estimation may be performed every time the motor 5 is started, or when a specified operation is performed on the motor control device 1.
  • FIG. 7 is a functional block diagram showing the configuration of a motor control device according to a second embodiment of the present invention.
  • the motor control device 1 of this embodiment does not have a current control system. Therefore, the dq-axis current detection values are not corrected to compensate for the gain error of the current sensor 11.
  • the motor control device 1 of this embodiment operates when current control is not being performed while the motor is being driven but motor current is flowing, i.e., when the dq-axis current command value and the actual dq-axis current flowing do not match, for example, when a three-phase short circuit of the inverter 4 is performed for overvoltage protection, etc.
  • the configuration of the motor control device 1 of this embodiment 2 is the part that operates in the above case in the motor control device of embodiment 1 ( Figure 1).
  • FIG. 8 is a functional block diagram showing the configuration of the error calculation unit 100 (FIG. 7) in the second embodiment.
  • the three-phase current amplitude estimation unit 101 calculates the three-phase motor current amplitude values I UVW based on the above-mentioned equations (5), (7), and (8), where the current phase ⁇ c in the rotating coordinate system is calculated from the d-axis and q-axis current detection values i dq using equation (15).
  • the motor state determination unit 103 in the second embodiment determines the state of the motor 5 (FIG. 7) by using the dq-axis current detection values i dq instead of the dq-axis current command values i* dq (FIG. 2).
  • FIG. 9 is a functional block diagram showing the configuration of the correction amount calculation unit 200 (FIG. 7) in the second embodiment.
  • FIG. 10 is a flowchart showing the operation of the correction destination selection unit 303.
  • Steps S301, S303, S304, S305, S306, S307, and S308 shown in FIG. 10 correspond to steps S201, S202, S204, S205, S206, S203, and S207 in FIG. 6 (Example 1), respectively.
  • step S301 when the correction destination selection unit 303 starts processing (step S301), it determines in step S302 whether current control is enabled. In this embodiment 2, since current control is not executed, the correction destination selection unit 303 determines that current control is not enabled (NO in step S302) and then executes step S306.
  • step S306 the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to output "0" (vector amount) as ⁇ i dq , and instructs the three-phase current correction amount calculation unit 202 to calculate and output m uvw using err uvw .
  • step S308 the correction destination selection unit 303 ends the series of processes.
  • the gain error of the current sensor is calculated based on the three-phase AC current amplitude value, and the three-phase current detection value is corrected based on the calculated gain error.
  • the present invention is not limited to the above-described embodiments, but includes various modified examples.
  • the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described.
  • 1 Motor control device 2 dq axis current command value, 3 Controller, 4 Inverter, 5 Motor, 6 Electrical angle calculation unit, 7 Electrical angular velocity calculation unit, 8 A/D converter, 9 Three-phase/dq axis converter, 10a dq axis current correction unit, 10b Three-phase current correction unit, 100 Error calculation unit, 200 Correction amount calculation unit, 101 Three-phase current amplitude estimation unit, 102 Error estimation unit, 103 Motor state determination unit, 201 dq axis current correction amount calculation unit, 202 Three-phase current correction amount calculation unit, 203 Correction destination selection unit, 303 Correction destination selection unit.

Abstract

Disclosed is a motor control device that is capable of estimating and compensating for a gain error of an electric current sensor in a stable and accurate manner, without being equipped with a special operating sequence. This motor control device (1) generates a control signal (D*uvw) for an inverter (4) that drives an AC motor (5), the motor control device comprising: an error calculation unit (100) that calculates a gain error (erruvw) of an electric current sensor (11) by using an amplitude value of a three-phase motor electric current detected by the electric current sensor; and a correction amount calculation unit (200) that, on the basis of the gain error estimated by the error calculation unit, calculates electric current correction amounts (muvw, Δidp) for compensating for the gain error.

Description

モータ制御装置Motor Control Device
　本発明は、モータのトルクや速度を制御するモータ制御装置に関する。 The present invention relates to a motor control device that controls the torque and speed of a motor.
　モータ制御装置は、モータのトルクや速度が指令値に追従するように、モータ電流を制御する。このとき、モータ電流の時間高調波やモータ磁束の空間高調波により、トルクリプルが生じる。トルクリプルは、振動や騒音の発生要因となる。モータ制御装置は、トルクリプルを低減するために、トルクリプル抑制制御を実行する。トルクリプル抑制制御においては、トルクリプル推定値に応じて電流指令値が補正される。 The motor control device controls the motor current so that the motor torque and speed follow the command values. At this time, torque ripple occurs due to time harmonics of the motor current and spatial harmonics of the motor magnetic flux. Torque ripple is a cause of vibration and noise. In order to reduce the torque ripple, the motor control device executes torque ripple suppression control. In torque ripple suppression control, the current command value is corrected according to the torque ripple estimate value.
　トルクリプルは、電流センサのゲイン誤差によっても発生する。電流センサにゲイン誤差がある場合、モータ電流検出値から変換されるｄｑ軸電流に、二次の振動成分が発生する（例えば、後述する特許文献１に記載の「式（２）」参照）。モータ制御装置は、この振動成分を除去するように電流制御を実行する。このため、モータ電流に電流リプルが生じるので、トルクリプルが発生する。 Torque ripple can also occur due to a gain error in the current sensor. If there is a gain error in the current sensor, a secondary vibration component occurs in the dq axis current converted from the motor current detection value (see, for example, "Equation (2)" in Patent Document 1 described below). The motor control device executes current control to remove this vibration component. This causes a current ripple in the motor current, which in turn generates a torque ripple.
　このような電流センサのゲイン誤差を推定・補正する従来技術として、特許文献１に記載された技術が知られている。 　The technology described in Patent Document 1 is known as a conventional technology for estimating and correcting the gain error of such a current sensor.
　本従来技術では、モータ制御装置は、動作モードとして、通常の動作モードとＣＴ補正駆動モードを備えている。ＣＴ補正駆動モードにおいては、電流制御部において、ｄ軸電流制御部およびｑ軸電流制御部は停止状態となり、非干渉制御部のみが動作を継続する。このような動作状態において、ｄ軸電流指令値Ｉｄ＊およびｑ軸電流指令値Ｉｑ＊のいずれか一方を零に設定し、ｄｑ軸の一方にのみ電流を流す。このときｄ軸電流検出値およびｑ軸電流検出値のいずれかに含まれる脈動成分のみを抽出して、ＣＴゲイン誤差を算出する。算出されたＣＴゲイン誤差に基づいて、三相電流演算部におけるゲインを補正する。 In this conventional technology, the motor control device has two operating modes: a normal operating mode and a CT correction drive mode. In the CT correction drive mode, in the current control section, the d-axis current control section and the q-axis current control section are stopped, and only the non-interference control section continues to operate. In this operating state, either the d-axis current command value Id* or the q-axis current command value Iq* is set to zero, and current flows only in one of the d and q axes. At this time, only the pulsating component contained in either the d-axis current detection value or the q-axis current detection value is extracted to calculate the CT gain error. The gain in the three-phase current calculation section is corrected based on the calculated CT gain error.
　本従来技術によるモータ制御装置は、通常の動作モードとして起動後、ＣＴ補正駆動モードを経て、再び通常の動作モードに復帰する動作シーケンスを備えている。 The motor control device according to this conventional technology has an operating sequence in which it starts up in a normal operating mode, goes through a CT correction drive mode, and then returns to the normal operating mode.
特開２０１６－１９３４１号公報JP 2016-19341 A
　上記従来技術では、電流センサのゲイン誤差を推定・補正するために、モータ制御装置が特別な動作シーケンスを備えている。このため、シーケンス実施条件の設定や、シーケンス切り替え時における制御の安定化などのため、モータ制御装置の開発期間や開発コストが増加する可能性がある。 In the above conventional technology, the motor control device is equipped with a special operation sequence to estimate and correct the gain error of the current sensor. This means that the development time and development costs of the motor control device may increase due to the need to set sequence execution conditions and stabilize control when switching sequences.
　そこで、本発明は、特別な動作シーケンスを備えることなく、安定かつ正確に電流センサのゲイン誤差を推定・補償できるモータ制御装置を提供する。 The present invention provides a motor control device that can stably and accurately estimate and compensate for the gain error of a current sensor without requiring a special operating sequence.
　上記課題を解決するために、本発明によるモータ制御装置は、交流モータを駆動するインバータの制御信号を生成するものであって、電流センサによって検出される三相モータ電流の振幅値を用いて電流センサのゲイン誤差を計算する誤差計算部と、誤差計算部によって推定されるゲイン誤差に基づいて、ゲイン誤差を補償するための電流補正量を計算する補正量計算部と、を備える。 In order to solve the above problems, the motor control device according to the present invention generates a control signal for an inverter that drives an AC motor, and includes an error calculation unit that calculates the gain error of the current sensor using the amplitude value of the three-phase motor current detected by the current sensor, and a correction amount calculation unit that calculates a current correction amount to compensate for the gain error based on the gain error estimated by the error calculation unit.
　本発明によれば、特別な動作シーケンスによらず、安定かつ正確に電流センサのゲイン誤差を推定・補償できる
　上記した以外の課題、構成および効果は、以下の実施形態の説明により明らかにされる。 According to the present invention, it is possible to stably and accurately estimate and compensate for the gain error of a current sensor without relying on a special operation sequence. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments.
実施例１であるモータ制御装置の構成を示す機能ブロック図である。1 is a functional block diagram illustrating a configuration of a motor control device according to a first embodiment. 実施例１における誤差計算部の構成を示す機能ブロック図である。FIG. 4 is a functional block diagram illustrating a configuration of an error calculation unit in the first embodiment. 実施例１における補正量計算部の構成を示す機能ブロック図である。FIG. 4 is a functional block diagram illustrating a configuration of a correction amount calculation unit in the first embodiment. 誤差推定部１０２の動作の変更を示す状態遷移図である。10 is a state transition diagram showing a change in the operation of the error estimating unit 102. FIG. モータ状態判定部１０３の動作を示すフローチャートである。4 is a flowchart showing an operation of a motor state determination unit 103. 補正先選択部２０３の動作を示すフローチャートである。10 is a flowchart showing an operation of a correction destination selection unit 203. 実施例２であるモータ制御装置の構成を示す機能ブロック図である。FIG. 11 is a functional block diagram showing a configuration of a motor control device according to a second embodiment. 実施例２における誤差計算部の構成を示す機能ブロック図である。FIG. 11 is a functional block diagram illustrating a configuration of an error calculation unit in the second embodiment. 実施例２における補正量計算部の構成を示す機能ブロック図である。FIG. 11 is a functional block diagram illustrating a configuration of a correction amount calculation unit in the second embodiment. 補正先選択部３０３の動作を示すフローチャートである。10 is a flowchart showing the operation of a correction destination selection unit 303.
　以下、本発明の実施形態について、下記の実施例１～２により、図面を用いながら説明する。 The following describes an embodiment of the present invention using the following Examples 1 and 2 with reference to the drawings.
　各図において、参照番号が同一のものは同一の構成要件あるいは類似の機能を備えた構成要件を示している。 In each figure, the same reference numbers indicate the same components or components with similar functions.
　図１は、本発明の実施例１であるモータ制御装置の構成を示す機能ブロック図である。 FIG. 1 is a functional block diagram showing the configuration of a motor control device according to a first embodiment of the present invention.
　以下の記載において、「ｄｑ軸」という記載は、「ｄ軸およびｑ軸」を表す。また、以下に記載する添え字付きのパラメータＸ（「ｉ」など）については、特に断らない限り、「Ｘｄｑ」は「ベクトル量（Ｘｄ，Ｘｑ）」を表し、「Ｘｕｖｗ」は「ベクトル量（Ｘｕ，Ｘｖ，Ｘｗ）」を表す。ここで、「ｕｖｗ」は、交流の三相すなわち「Ｕ相、Ｖ相およびＷ相」を表す。 In the following description, the term "dq axis" refers to the "d axis and q axis." In addition, for the subscripted parameter X (such as "i") described below, unless otherwise specified, "X dq " refers to a "vector quantity (X d , X q )" and "X uvw " refers to a "vector quantity (X u , X v , X w )." Here, "uvw" refers to three phases of AC, that is, "U phase, V phase, and W phase."
　モータ制御装置１は、モータ５に交流電力を供給するインバータ４のスイッチングを制御することにより、モータ５の速度やトルクを制御する。 The motor control device 1 controls the speed and torque of the motor 5 by controlling the switching of the inverter 4 that supplies AC power to the motor 5.
　本実施例において、モータ制御装置１は、マイクロコンピュータなどの演算処理装置によって構成され、所定のプログラムを実行することにより、各部として機能する。 In this embodiment, the motor control device 1 is configured with a processing device such as a microcomputer, and functions as each part by executing a specific program.
　本実施例において、インバータ４は、ＩＧＢＴやＭＯＳＦＥＴのような半導体スイッチング素子から構成される三相フルブリッジ回路を主回路とする三相インバータである。 In this embodiment, the inverter 4 is a three-phase inverter whose main circuit is a three-phase full-bridge circuit composed of semiconductor switching elements such as IGBTs and MOSFETs.
　モータ制御装置１が生成する制御信号Ｄ＊ｕｖｗによって、インバータ４の主回路を構成する半導体スイッチング素子のオン・オフが制御される。これにより、インバータ４は、蓄電池などの直流電源から入力する直流電力を三相交流電力に変換し、三相交流電圧ｖｕｖｗを出力する。制御信号Ｄ＊ｕｖｗは、半導体スイッチング素子がＩＧＢＴやＭＯＳＦＥＴである場合、半導体スイッチング素子のゲート制御信号である。 The control signal D* uvw generated by the motor control device 1 controls the on/off of the semiconductor switching elements that constitute the main circuit of the inverter 4. As a result, the inverter 4 converts DC power input from a DC power source such as a storage battery into three-phase AC power and outputs a three-phase AC voltage v uvw . The control signal D* uvw is a gate control signal for the semiconductor switching elements when the semiconductor switching elements are IGBTs or MOSFETs.
　制御信号Ｄ＊ｕｖｗは、インバータ４の主回路である三相フルブリッジ回路のスイッチングを制御するため、６個の制御信号、すなわちＵ相上アーム用制御信号（Ｄ＊ｕｐ）、Ｕ相下アーム用制御信号（Ｄ＊ｕｎ）、Ｖ相上アーム用制御信号（Ｄ＊ｖｐ）、Ｖ相下アーム用制御信号（Ｄ＊ｖｎ）、Ｗ相上アーム用制御信号（Ｄ＊ｗｐ）およびＷ相下アーム用制御信号（Ｄ＊ｗｎ）から構成される。なお、添え字ｐ，ｎは、それぞれ上アーム、下アームを表す。 The control signal D* uvw is composed of six control signals, namely, a control signal for the U-phase upper arm (D* up ), a control signal for the U-phase lower arm (D* un ), a control signal for the V-phase upper arm (D* vp ), a control signal for the V-phase lower arm (D* vn ), a control signal for the W-phase upper arm (D* wp ) and a control signal for the W-phase lower arm (D* wn ), in order to control the switching of the three-phase full-bridge circuit which is the main circuit of the inverter 4. Note that the subscripts p and n represent the upper arm and lower arm, respectively.
　本実施例において、モータ５としては、回転機である三相交流同期モータ、例えば、永久磁石同期モータが適用される。 In this embodiment, the motor 5 is a three-phase AC synchronous motor, which is a rotating machine, such as a permanent magnet synchronous motor.
　モータ５としては、同期機に限らず、誘導機が適用されてもよい。また、モータ５としては、回転機に限らず、リニアモータが適用されてもよい。なお、モータ５は、発電機能を有してもよい。 The motor 5 is not limited to a synchronous machine, and an induction machine may be used. The motor 5 is not limited to a rotating machine, and a linear motor may be used. The motor 5 may have a power generation function.
　図１に示すように、モータ制御装置１は、ｄｑ軸電流指令値２（ｉ＊ｄｑ）と、制御器３と、電気角計算部６と、電気角速度計算部７と、Ａ／Ｄ変換器８と、三相／ｄｑ軸変換器９と、ｄｑ軸電流補正部１０ａと、三相電流補正部１０ｂと、電流センサ１１と、誤差計算部１００と、補正量計算部２００と、を備える。 As shown in FIG. 1, the motor control device 1 includes a dq-axis current command value 2 (i* dq ), a controller 3, an electrical angle calculation unit 6, an electrical angular velocity calculation unit 7, an A/D converter 8, a three-phase/dq-axis converter 9, a dq-axis current correction unit 10a, a three-phase current correction unit 10b, a current sensor 11, an error calculation unit 100, and a correction amount calculation unit 200.
　制御器３は、ｄｑ軸電流検出値ｉｄｑとｄｑ軸電流指令値ｉ＊ｄｑ（２）との差分に応じて、ｉｄｑがｉ＊ｄｑに一致するように、インバータ４のスイッチングを制御する制御信号Ｄｕｖｗ＊を生成する。本実施例において、ｄｑ軸電流補正部１０ａは、制御器３へ入力される差分量をｄｑ軸電流補正量Δｉｄｑによって補正する。Δｉｄｑは、ｉｄｑの補正量であり、後述するように、電流センサ１１のゲイン誤差に起因するｄｑ軸電流検出値ｉｄｑの振動成分の発生を補償する。 The controller 3 generates a control signal D uvw * for controlling the switching of the inverter 4 in accordance with the difference between the dq-axis current detection value i dq and the dq-axis current command value i* dq (2) so that i dq coincides with i * dq . In this embodiment, the dq-axis current correction unit 10a corrects the difference input to the controller 3 by a dq-axis current correction amount Δi dq . Δi dq is the correction amount of i dq , and compensates for the generation of vibration components of the dq-axis current detection value i dq caused by the gain error of the current sensor 11, as will be described later.
　本実施例においては、制御器３は、公知の構成を有している。例えば、制御器３は、ＰＩ演算によりｄｑ軸電圧指令値を作成するｄｑ軸電流制御器と、ｄｑ軸電圧指令値を三相電圧指令値に変換するｄｑ／三相変換器と、三相電圧指令値に応じてインバータの制御信号を生成するＰＷＭ制御器とから構成される。なお、ＰＩ演算に代えて、公知の電圧方程式を用いて、ｄｑ軸電圧指令値を作成してもよい。 In this embodiment, the controller 3 has a known configuration. For example, the controller 3 is composed of a dq-axis current controller that creates dq-axis voltage command values by PI calculation, a dq/three-phase converter that converts the dq-axis voltage command values into three-phase voltage command values, and a PWM controller that generates inverter control signals according to the three-phase voltage command values. Note that instead of PI calculation, the dq-axis voltage command values may be created using known voltage equations.
　電気角計算部６は、モータ５が備える回転センサ（図示せず）からの回転位置信号に基づき、電気角θｅを計算して出力する。回転センサは、モータ５の回転子の機械角（θｍ）に応じて回転位置信号を出力するが、電気角計算部６は、モータ５の極対数（ｐ）、並びに、θｅとθｍとｐとの関係（θｅ＝ｐ・θｍ）を用いて、θｅを計算する。 The electrical angle calculation unit 6 calculates and outputs the electrical angle θe based on a rotational position signal from a rotation sensor (not shown) provided in the motor 5. The rotation sensor outputs a rotational position signal according to the mechanical angle ( θm ) of the rotor of the motor 5, but the electrical angle calculation unit 6 calculates θe using the number of pole pairs (p) of the motor 5 and the relationship between θe , θm , and p ( θe =p· θm ).
　回転センサとしては、レゾルバ、ホールセンサ、ロータリエンコーダなどが適用できる。 Resolvers, Hall sensors, rotary encoders, etc. can be used as rotation sensors.
　電気角速度計算部７は、電気角計算部６と同様にモータ５が備える回転センサ（図示せず）からの回転位置信号に基づき、電気角速度ωｅを計算して出力する。電気角速度計算部７は、モータ５の極対数（ｐ）、電気角θｅと機械角θｍとｐとの関係（θｅ＝ｐ・θｍ）およびθｅとωｅの関係（ωｅ＝ｄθｅ／ｄｔ）用いて、ωｅを計算する。なお、電気角速度計算部７は、電気角計算部６の出力するθｅを微分してωｅを計算する微分器によって構成されてもよい。 Like the electrical angle calculation unit 6, the electrical angular velocity calculation unit 7 calculates and outputs the electrical angular velocity ωe based on a rotational position signal from a rotation sensor (not shown) provided in the motor 5. The electrical angular velocity calculation unit 7 calculates ωe using the number of pole pairs (p) of the motor 5, the relationship between the electrical angle θe and the mechanical angles θm and p ( θe = p · θm ), and the relationship between θe and ωe ( ωe = dθe / dt). Note that the electrical angular velocity calculation unit 7 may be configured by a differentiator that differentiates θe output from the electrical angle calculation unit 6 to calculate ωe .
　Ａ／Ｄ変換器８は、インバータ４の出力とモータ５との間の配線ケーブルに流れる三相モータ実電流値ｉｒｅａｌｕｖｗを電流センサ１１によって取得するときの電流センサ１１の電流検出信号を、モータ制御装置１が扱うデジタル値に変換して、三相モータ電流検出値ｉｍｅａｓｕｖｗとして出力する。 The A/D converter 8 converts the current detection signal of the current sensor 11, obtained when the current sensor 11 acquires the three-phase motor actual current value i real uvw flowing in the distribution cable between the output of the inverter 4 and the motor 5, into a digital value handled by the motor control device 1, and outputs it as the three-phase motor current detection value i meas uvw .
　三相／ｄｑ軸変換器９は、Ａ／Ｄ変換器８からの三相モータ電流検出値ｉｍｅａｓｕｖｗと電気角計算部６からの電気角θｅに基づきｄｑ軸電流検出値ｉｄｑを計算する。本実施例において、三相電流補正部１０ｂは、後述する補正係数ｍｕｖｗによってｉｍｅａｓｕｖｗを補正する。補正された三相モータ電流検出値が三相／ｄｑ軸変換器９に入力される。後述するように、補正係数ｍｕｖｗは、電流センサ１１のゲイン誤差（以下、「誤差」と記す）に起因するｄｑ軸電流検出値ｉｄｑの振動成分の発生を補償する。 The three-phase/dq-axis converter 9 calculates the dq-axis current detection value i dq based on the three-phase motor current detection value i meas uvw from the A/D converter 8 and the electrical angle θe from the electrical angle calculation unit 6. In this embodiment, the three-phase current correction unit 10b corrects i meas uvw by a correction coefficient m uvw described later. The corrected three-phase motor current detection value is input to the three-phase/dq-axis converter 9. As described later, the correction coefficient m uvw compensates for the generation of vibration components in the dq-axis current detection value i dq caused by a gain error (hereinafter referred to as "error") of the current sensor 11.
　電流センサ１１は、三相の配線ケーブルの各々、もしくは、三相の配線ケーブルの内の二相に設けられる。電流センサ１１を二相分の配線ケーブルに設ける場合、Ａ／Ｄ変換器８は、二相分の検出信号をデジタル値に変換し、二相分のモータ電流検出値とする。さらに、三相モータ電流の和が零になることを用いて、図示しない演算器（加減算器）によって、残る一相分のモータ電流値が計算される。 Current sensors 11 are provided on each of the three-phase distribution cables, or on two of the three-phase distribution cables. When current sensors 11 are provided on two-phase distribution cables, A/D converter 8 converts the detection signals for the two phases into digital values, which are used as motor current detection values for the two phases. Furthermore, by using the fact that the sum of the three-phase motor currents is zero, a calculator (adder/subtractor) (not shown) calculates the motor current value for the remaining phase.
　なお、電流センサ１１としては、電流トランス（ＣＴ）やホール素子などが適用される。 In addition, a current transformer (CT) or a Hall element is used as the current sensor 11.
　誤差計算部１００は、三相モータ電流検出値ｉｍｅａｓｕｖｗと、電気角θｅと、電気角速度ωｅと、ｄｑ軸電流指令値ｉｄｑ＊とに基づいて、電流センサ１１の誤差ｅｒｒｕｖｗを計算する。 The error calculation unit 100 calculates the error err uvw of the current sensor 11 based on the three-phase motor current detection value imeas uvw , the electrical angle θ e , the electrical angular velocity ω e , and the dq-axis current command value i dq *.
　補正量計算部２００は、誤差計算部１００によって計算されたｅｒｒｕｖｗと、ｄｑ軸電流指令値ｉ＊ｄｑとに基づいて、ｄｑ軸電流補正部１０ａにおいて用いられるｄｑ軸電流補正量Δｉｄｑと、三相電流補正部１０ｂにおいて用いられる補正係数ｍｕｖｗとを計算する。 The correction amount calculation unit 200 calculates the dq-axis current correction amount Δi dq used in the dq-axis current correction unit 10a and the correction coefficient m uvw used in the three-phase current correction unit 10b, based on the err uvw calculated by the error calculation unit 100 and the dq-axis current command value i* dq .
　図２は、実施例１における誤差計算部１００（図１）の構成を示す機能ブロック図である。 FIG. 2 is a functional block diagram showing the configuration of the error calculation unit 100 (FIG. 1) in the first embodiment.
　図２に示すように、誤差計算部１００は、三相電流振幅推定部１０１と、誤差推定部１０２と、モータ状態判定部１０３とを備えている。 As shown in FIG. 2, the error calculation unit 100 includes a three-phase current amplitude estimation unit 101, an error estimation unit 102, and a motor state determination unit 103.
　三相電流振幅推定部１０１は、三相モータ電流検出値ｉｍｅａｓｕｖｗ（＝（ｉｍｅａｓｕ，Ｉｍｅａｓｖ，Ｉｍｅａｓｗ））と、電気角θｅおよび電気角速度ωｅ（図１）と、ｄｑ軸電流指令値Ｉ＊ｄｑ（＝（Ｉ＊ｄ，Ｉ＊ｑ））とに基づいて、三相モータ電流振幅値ＩＵＶＷ（＝（ＩＵ，ＩＶ，ＩＷ）を推定する。なお、添え字「ＵＶＷ」は、交流の三相すなわち「Ｕ相、Ｖ相およびＷ相」を表す。 A three-phase current amplitude estimation unit 101 estimates three-phase motor current amplitude values I UVW (=(I U , IV , IW )) based on three-phase motor current detection values I meas uvw (=(I meas u , I meas v , I meas w )), the electrical angle θ e and the electrical angular velocity ω e ( FIG. 1 ), and a dq-axis current command value I* dq (=(I* d , I * q ) ) . Note that the subscripts “UVW” represent the three phases of AC, i.e., “U phase, V phase, and W phase.”
　モータ状態判定部１０３は、ｄｑ軸電流指令値ｉ＊ｄｑに基づいて、モータ５（図１）の状態を判定する。 The motor state determination unit 103 determines the state of the motor 5 (FIG. 1) based on the dq axis current command values i* dq .
　誤差推定部１０２は、モータ状態判定部１０３によって判定されたモータ５の状態に応じて、三相電流振幅推定部１０１によって推定された三相モータ電流振幅値ＩＵＶＷに基づいて電流センサ１１（図１）の誤差ｅｒｒｕｖｗを計算して推定する。 The error estimation unit 102 calculates and estimates the error err uvw of the current sensor 11 ( FIG. 1 ) based on the three-phase motor current amplitude values I UVW estimated by the three-phase current amplitude estimation unit 101 in accordance with the state of the motor 5 determined by the motor state determination unit 103.
　図３は、実施例１における補正量計算部２００（図１）の構成を示す機能ブロック図である。 FIG. 3 is a functional block diagram showing the configuration of the correction amount calculation unit 200 (FIG. 1) in the first embodiment.
　図３に示すように、補正量計算部２００は、ｄｑ軸電流補正量計算部２０１と、三相電流補正量計算部２０２と、補正先選択部２０３とを有している。 As shown in FIG. 3, the correction amount calculation unit 200 includes a dq-axis current correction amount calculation unit 201, a three-phase current correction amount calculation unit 202, and a correction destination selection unit 203.
　ｄｑ軸電流補正量計算部２０１は、誤差計算部１００（図１，２）によって計算された誤差ｅｒｒｕｖｗ（＝（ｅｒｒｕ，ｅｒｒｖ，ｅｒｒｗ））と、機械角θｅ（図１）と、ｄｑ軸電流指令値ｉ＊ｄｑとに基づいて、ｄｑ軸電流補正量Δｉｄｑ（＝（Δｉｄ，Δｉｑ））を計算する。 The dq-axis current correction amount calculation unit 201 calculates the dq-axis current correction amount Δi dq (=(Δi d , Δi q )) based on the error err uvw (=(err u , err v , err w )) calculated by the error calculation unit 100 (Figures 1 and 2), the mechanical angle θ e ( Figure 1 ), and the dq-axis current command value i* dq .
　三相電流補正量計算部２０２は、誤差ｅｒｒｕｖｗに基づいて、補正係数ｍｕｖｗ（＝（ｍｕ，ｍｖ，ｍｗ））を計算する。 The three-phase current correction amount calculation unit 202 calculates a correction coefficient m uvw (=(m u , m v , m w )) based on the error err uvw .
　補正先選択部２０３は、Δｉｄｑおよびｍｕｖｗから、電流センサ１１の誤差に起因するｄｑ軸電流検出値ｉｄｑの振動成分の発生を補償するために用いる補正量を選択する。すなわち、補正先選択部２０３は、ｄｑ軸電流補正量計算部２０１および三相電流補正量計算部２０２から、補正量の計算を実行する補正量計算部を選択する。 The correction destination selection unit 203 selects, from Δi dq and m uvw , a correction amount used to compensate for the occurrence of vibration components in the dq-axis current detection value i dq caused by the error of the current sensor 11. That is, the correction destination selection unit 203 selects, from the dq-axis current correction amount calculation unit 201 and the three-phase current correction amount calculation unit 202, a correction amount calculation unit that executes calculation of the correction amount.
　ここで、電流センサ１１の誤差に起因するｄｑ軸電流検出値の振動成分の発生について、概略的に説明する。 Here, we provide an overview of the generation of vibration components in the d- and q-axis current detection values caused by errors in the current sensor 11.
　電流センサ１１に誤差ｅｒｒｕｖｗが有る場合の三相モータ電流検出値ｉｍｅａｓｕｖｗを何ら補正することなく回転座標へ座標変換すると、ｄｑ軸電流検出値ｉｄｑは式（１）で表される。 When the three-phase motor current detection value imeas uvw in the case where the current sensor 11 has an error err uvw is transformed into the rotating coordinate system without any correction, the dq-axis current detection value i dq is expressed by the formula (1).
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　式（１）の左辺においては、ｉｄｑを列ベクトルで表している。右辺第一項の列ベクトルは、ｉｒｅａｌｕｖｗを座標変換して得られるｉｒｅａｌｄｑを表す。右辺第二および第三項における位相ψは、後述するように（式（１２）参照）、一定値の位相量である。 In the left side of equation (1), i dq is expressed as a column vector. The column vector in the first term on the right side represents i real dq obtained by coordinate transformation of i real uvw . The phase ψ in the second and third terms on the right side is a constant phase amount, as described later (see equation (12)).
　式（１）の右辺第二および第三項が示すように、電流センサ１１に誤差ｅｒｒｕｖｗが有る場合、ｉｒｅａｌｄｑに対して誤差となる直流成分（第二項）および２次の振動成分（第三項）が生じる。 As the second and third terms on the right side of equation (1) indicate, when the current sensor 11 has an error err uvw , a DC component (second term) and a second-order vibration component (third term) that become errors with respect to ireal dq are generated.
　このように、ｉｒｅａｌｕｖｗが振動成分を含まなくても、電流センサ１１の誤差が有ると、ｉｄｑに振動成分が生じる。 In this way, even if i real uvw does not contain any oscillatory components, if there is an error in the current sensor 11, an oscillatory component occurs in i dq .
　以下、上述のような電流センサ１１の誤差に起因するｄｑ軸電流検出値ｉｄｑに発生する振動成分を補償するための、実施例１によるモータ制御装置１の動作について説明する。なお、適宜、図１～３を参照しながら、説明する。 Hereinafter, a description will be given of the operation of the motor control device 1 according to the first embodiment for compensating for the vibration components occurring in the dq-axis current detection values i dq due to the error of the current sensor 11 as described above. The description will be made with reference to FIGS. 1 to 3 as needed.
　三相電流補正部１０ｂ（図１）は、式（２）に基づいて、三相モータ電流検出値ｉｍｅａｓｕｖｗを補正する。 The three-phase current correction unit 10b (FIG. 1) corrects the three-phase motor current detection values i meas uvw based on the equation (2).
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　式（２）が示すように、三相電流補正部１０ｂは、ｉｍｅａｓｕｖｗに、補正量計算部２００（図１）によって計算された補正係数ｍｕｖｗを乗じて、補正された三相モータ電流検出値ｉｍｅａｓｕｖｗ’（＝（ｉｍｅａｓｕ’，ｉｍｅａｓｖ’，ｉｍｅａｓｗ’）＝（ｍｕ・ｉｍｅａｓｕ，ｍｖ・ｉｍｅａｓｖ，ｍｗ・ｉｍｅａｓｗ））として三相／ｄｑ軸変換器９（図１）へ出力する。 As shown in equation (2), the three-phase current correction unit 10b multiplies i_meas uvw by the correction coefficient m_uvw calculated by the correction amount calculation unit 200 (FIG. 1), and outputs the result as a corrected three-phase motor current detection value i_meas uvw ' (=(i_meas u ', i_meas v ', i_meas w ')=( m_u ·i_meas u , m_v ·i_meas v , m_w ·i_meas w )) to the three-phase/dq-axis converter 9 (FIG. 1).
　なお、誤差計算部１００（図１）によって誤差ｅｒｒｕｖｗの計算が実行される前は、ｍｕｖｗ（＝（ｍｕ，ｍｖ，ｍｗ））は（１，１，１）に設定される。 Note that before the error err uvw is calculated by the error calculation unit 100 (FIG. 1), m uvw (=(m u , m v , m w )) is set to (1, 1, 1).
　三相／ｄｑ軸変換器９は、補正された三相モータ電流検出値ｉｍｅａｓｕｖｗ’と、電気角θｅとから、式（３）に基づいてｄｑ軸電流検出値ｉｄｑを計算する。 The three-phase/dq-axis converter 9 calculates the dq-axis current detection value i dq from the corrected three-phase motor current detection value i meas uvw ′ and the electrical angle θ e according to equation (3).
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　制御器３（図１）は、このようなｄｑ軸電流検出値ｉｄｑを用いて、前述のようにインバータ４（図１）のスイッチングを制御する制御信号Ｄ＊ｕｖｗを生成する。 The controller 3 (FIG. 1) uses such dq-axis current detection values i_dq to generate the control signal D* uvw for controlling the switching of the inverter 4 (FIG. 1) as described above.
　次に、誤差計算部１００（図２）の動作について説明する。 Next, the operation of the error calculation unit 100 (Figure 2) will be explained.
　まず、三相電流振幅推定部１０１における三相モータ電流振幅値ＩＵＶＷの推定手段について、Ｕ相モータ電流振幅値ＩＵを例にして説明する。 First, the means for estimating the three-phase motor current amplitude values IUVW in the three-phase current amplitude estimator 101 will be described using the U-phase motor current amplitude value IU as an example.
　Ｕ相モータ電流検出値ｉｍｅａｓｕとＵ相モータ電流振幅値ＩＵとは、式（４）の関係にある。 The U-phase motor current detection value i_meas u and the U-phase motor current amplitude value IU have the relationship shown in Equation (4).
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　式（４）においては、モータ５におけるＵ相磁束を位相基準としている。 In equation (4), the U-phase magnetic flux in motor 5 is used as the phase reference.
　式（４）に基づいて、Ｉｕは式（５）で表される。 Based on equation (4), Iu is expressed by equation (5).
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　なお、電流検出タイミングが、電気角θｅの検出タイミングに対してΔｔだけ遅れる場合、電気角θｅをωｅΔｔだけ進める補正を行ってもよい。 When the current detection timing is delayed by Δt with respect to the detection timing of the electrical angle θ e , the electrical angle θ e may be corrected to be advanced by ω e Δt.
　式（４）および（５）におけるβｃは、回転座標系における電流位相であり、ｄｑ軸電流検出値ｉｄｑから計算できるが、本実施例では、式（６）を用いて、ｄｑ軸電流指令値ｉ＊ｄｑから計算される。 βc in equations (4) and (5) is a current phase in a rotating coordinate system and can be calculated from the dq-axis current detection values i dq . In this embodiment, however, it is calculated from the dq-axis current command values i* dq using equation (6).
Figure JPOXMLDOC01-appb-M000006
Figure JPOXMLDOC01-appb-M000006
　これにより、ｉｄｑに含まれる電流センサの誤差やノイズのβｃに対する影響が抑えられる。また、周波数として表される電流制御応答相当のローパスフィルタ（ＬＰＦ）を通したｉ＊ｄｑに基づきβｃを計算してもよい。 This suppresses the effect of current sensor error and noise contained in i dq on β c. In addition, β c may be calculated based on i* dq that has been passed through a low-pass filter (LPF) equivalent to a current control response expressed as a frequency.
　なお、式（６）に代えて、さらに、βｃとｉｄｑとの対応を表すテーブルデータを用いてもよい。 In addition, instead of equation (6), table data representing the correspondence between β c and i dq may be used.
　Ｖ相およびＷ相モータ電流振幅値ＩＶ，ＩＷは、位相基準から、それぞれ、-２/３π、２/３πだけ位相をずらして、式（７）、式（８）で表される。 The V-phase and W-phase motor current amplitude values I V and I W are expressed by equations (7) and (8) with phases shifted by −2/3π and 2/3π, respectively, from the phase reference.
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000008
　三相電流振幅推定部１０１においては、式（６）～（８）の分母が三角関数であるため、電気角１周期について２度、ゼロ割もしくはゼロ割に非常に近い状態が発生する。実際の三相モータ電流は正弦波から歪むため、電流ゼロクロス付近で電流振幅値が大きく振れる可能性がある。したがって、誤差推定部１０２における誤差の計算精度が低下する可能性がある。そのため、三相電流振幅推定部１０１は、分母の三角関数の値がある一定値以下となる時、計算動作を停止して、予め設定される所定値を出力してもよい。 In the three-phase current amplitude estimation unit 101, because the denominators of equations (6) to (8) are trigonometric functions, a state of division by zero or very close to zero occurs twice per electrical angle cycle. Because the actual three-phase motor current is distorted from a sine wave, the current amplitude value may fluctuate significantly near the current zero crossing. This may reduce the accuracy of the error calculation in the error estimation unit 102. For this reason, when the value of the trigonometric function in the denominator falls below a certain value, the three-phase current amplitude estimation unit 101 may stop the calculation operation and output a predetermined value that is set in advance.
　誤差推定部１０２は、三相電流振幅推定部１０１から三相モータ電流振幅値ＩＵＶＷを受ける。もし、電流センサの誤差がなければ、三相平衡の条件下で、ＩＵ，ＩＶ，ＩＷは等しくなる。そこで、誤差推定部１０２は、ＩＵ，ＩＶ，ＩＷの平均値Ｉａｖｅ（＝（ＩＵ＋ＩＶ＋ＩＷ）／３）を真値として、式（９）を用いて、電流センサ１１の誤差ｅｒｒｕｖｗを計算して推定する。 Error estimator 102 receives three-phase motor current amplitude values I UVW from three-phase current amplitude estimator 101. If there are no current sensor errors, IU , IV , and IW will be equal under three-phase balance conditions. Therefore, error estimator 102 calculates and estimates error err uvw of current sensor 11 using equation (9) with average value I ave (=( IU + IV + IW )/3) of IU, IV , and IW as the true value .
Figure JPOXMLDOC01-appb-M000009
Figure JPOXMLDOC01-appb-M000009
　誤差推定部１０２は、モータ状態判定部１０３の出力（判定結果）に基づき動作を変更する。 The error estimation unit 102 changes its operation based on the output (determination result) of the motor state determination unit 103.
　図４は、誤差推定部１０２の動作の変更を示す状態遷移図である。 FIG. 4 is a state transition diagram showing changes in the operation of the error estimation unit 102.
　初期状態Ｓ１において、誤差推定部１０２は、初期値として設定した誤差ｅｒｒｕｖｗ（＝（ｅｒｒｕ，ｅｒｒｖ，ｅｒｒｗ））の値を出力する。本実施例では、初期値は（１，１，１）である。また、予め誤差がわかっている場合、その誤差を初期値として設定してもよい。 In the initial state S1, the error estimator 102 outputs the value of the error erruvw (=( erru , errv , errw )) set as the initial value. In this embodiment, the initial value is (1, 1, 1). In addition, when the error is known in advance, the error may be set as the initial value.
　モータ状態判定部１０３の出力が「誤差推定実施可」であれば、状態Ｓ２に遷移する。状態Ｓ２において、誤差推定部１０２は、式（９）に基づいて誤差を計算して出力する。 If the output of the motor state determination unit 103 is "error estimation possible", the state transitions to S2. In state S2, the error estimation unit 102 calculates and outputs the error based on equation (9).
　モータ状態判定部１０３の出力が、「誤差推定実施不可」であれば、状態Ｓ３に遷移する。状態Ｓ３において、誤差推定部１０２は、誤差として前回値を保持して出力する。 If the output of the motor state determination unit 103 is "error estimation not possible", the state transitions to S3. In state S3, the error estimation unit 102 holds and outputs the previous value as the error.
　図５は、モータ状態判定部１０３の動作を示すフローチャートである。 FIG. 5 is a flowchart showing the operation of the motor state determination unit 103.
　モータ状態判定部１０３は、処理を開始すると（ステップＳ１０１）、ステップＳ１０２において、式（６）で表されるモータ５の電流位相量βｃの時間変化率が所定の一定値以下であるかを判定する。モータ状態判定部１０３は、一定値以下であると判定すると（ステップＳ１０２のＹＥＳ）、次にステップＳ１０３を実行し、一定値以下ではない、すなわち一定値より大であると判定すると（ステップＳ１０２のＮＯ）、次にステップＳ１０５を実行する。 When the motor state determination unit 103 starts processing (step S101), it determines in step S102 whether the time rate of change of the current phase amount βc of the motor 5, expressed by equation (6), is equal to or less than a predetermined constant value. If the motor state determination unit 103 determines that it is equal to or less than the constant value (YES in step S102), it then executes step S103, and if it determines that it is not equal to or less than the constant value, i.e., that it is greater than the constant value (NO in step S102), it then executes step S105.
　ステップＳ１０３において、モータ状態判定部１０３は、誤差の推定を実施するかを判定する。モータ状態判定部１０３は、実施すると判定すると（ステップＳ１０３のＹＥＳ）、次にステップＳ１０４を実行し、実施しないと判定すると（ステップＳ１０３のＮＯ）、次にステップＳ１０５を実行する。 In step S103, the motor state determination unit 103 determines whether to perform error estimation. If the motor state determination unit 103 determines that an error estimation should be performed (YES in step S103), it next executes step S104, and if it determines that an error estimation should not be performed (NO in step S103), it next executes step S105.
　ステップＳ１０４において、モータ状態判定部１０３は、モータ状態の判定結果として「誤差推定実施可」を出力する。ステップＳ１０４を実行すると、モータ状態判定部１０３は、一連の処理を終了する。 In step S104, the motor state determination unit 103 outputs "error estimation possible" as the motor state determination result. After executing step S104, the motor state determination unit 103 ends the series of processes.
　ステップＳ１０５は、モータ状態判定部１０３は、モータ状態の判定結果として「誤差推定実施不可」を出力する。ステップＳ１０５を実行すると、モータ状態判定部１０３は、一連の処理を終了する。 In step S105, the motor state determination unit 103 outputs "error estimation not possible" as the motor state determination result. After executing step S105, the motor state determination unit 103 ends the series of processes.
　なお、ステップＳ１０３における判定基準は、誤差の推定精度が低下したり、計算負荷が増大したりする場合を考慮して、適宜設定される。 The criteria in step S103 are set appropriately, taking into account cases where the error estimation accuracy decreases or the calculation load increases.
　また、常に誤差の推定および補償を実施する場合には、ステップＳ１０３は省略してもよい。 In addition, if error estimation and compensation are always performed, step S103 may be omitted.
　また、式（９）が示すように、誤差の計算には電流振幅値による割り算が含まれるため、電流振幅値が小さい場合、誤差の計算精度が低下する可能性がある。そのような場合、モータ状態判定部１０３の動作に、電流振幅値が所定の一定値以下の場合に「誤差推定実施不可」を出力するような条件分岐を加えてもよい。 Also, as shown in equation (9), the error calculation includes division by the current amplitude value, so if the current amplitude value is small, the accuracy of the error calculation may decrease. In such a case, a conditional branch may be added to the operation of the motor state determination unit 103 so that "error estimation cannot be performed" is output when the current amplitude value is equal to or less than a predetermined constant value.
　次に、補正量計算部２００（図３）の動作について説明する。 Next, the operation of the correction amount calculation unit 200 (Figure 3) will be explained.
　ｄｑ軸電流補正量計算部２０１は、誤差計算部１００（図１、図２）によって計算された誤差ｅｒｒｕｖｗを用いて、式（１０）～（１３）に基づき、ｄｑ軸電流補正量Δｉｄｑ（＝（Δｉｄ，Δｉｑ））を計算する。 The dq axis current correction amount calculation unit 201 calculates the dq axis current correction amount Δi dq (=(Δi d , Δi q )) based on the equations (10) to (13) using the error err uvw calculated by the error calculation unit 100 (FIGS. 1 and 2).
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000012
Figure JPOXMLDOC01-appb-M000012
Figure JPOXMLDOC01-appb-M000013
Figure JPOXMLDOC01-appb-M000013
　本実施例では、式（１０）および式（１１）が示すように、式（１）の右辺第三項に示すようなｄｑ軸電流検出値ｉｄｑにおける２次の振動成分が補償される。なお、本実施例では、式（１）の右辺第二項に示すようなｄｑ軸電流の直流成分の発生は補償されない。このため、直流成分の補償に伴う予期せぬトルク精度の低下を抑制できる。 In this embodiment, as shown in equations (10) and (11), the second-order vibration component in the dq-axis current detection value i dq as shown in the third term on the right side of equation (1) is compensated for. Note that in this embodiment, the occurrence of the DC component of the dq-axis current as shown in the second term on the right side of equation (1) is not compensated for. Therefore, it is possible to suppress an unexpected decrease in torque accuracy due to compensation for the DC component.
　なお、電流制御帯域以上では補償なしでもよいため、モータ５の回転数に応じて徐々に補正量を修正してもよい。 Note that since no compensation is required above the current control band, the correction amount may be gradually adjusted according to the rotation speed of the motor 5.
　三相電流補正量計算部２０２は、ｅｒｒｕｖｗを用いて、式（１４）に基づき、補正係数ｍｕｖｗを計算する。 The three-phase current correction amount calculation unit 202 calculates a correction coefficient m uvw based on the equation (14) using err uvw .
Figure JPOXMLDOC01-appb-M000014
Figure JPOXMLDOC01-appb-M000014
　なお、ｍｕｖｗによる三相モータ電流検出値の補正は、Δｉｄｑによるｄｑ軸電流の補正に比べ、計算量が少なく、計算負荷が小さい。 The correction of the three-phase motor current detection values using m uvw requires less calculation and has a smaller calculation load than the correction of the dq axis currents using Δi dq .
　補正先選択部２０３は、条件に応じて、ｍｕｖｗおよびΔｉｄｑの内、誤差ｅｒｒｕｖｗを用いて計算する補正量を選択する。すなわち、補正先選択部２０３は、計算されたｍｕｖｗによる三相モータ電流検出値ｉｍｅａｓｕｖｗの補正と、計算されたΔｉｄｑによるｄｑ軸電流検出値の補正との内、いずれか一方を選択する。なお、予めいずれか一方が選択される場合には、補正先選択部２０３は、省略してもよい。 The correction destination selection unit 203 selects the amount of correction to be calculated using the error err uvw from among m uvw and Δi dq according to the conditions. That is, the correction destination selection unit 203 selects either the correction of the three-phase motor current detection value imeas uvw using the calculated m uvw or the correction of the dq-axis current detection value using the calculated Δi dq . Note that if either one of them is selected in advance, the correction destination selection unit 203 may be omitted.
　図６は、補正先選択部２０３の動作を示すフローチャートである。 FIG. 6 is a flowchart showing the operation of the correction destination selection unit 203.
　補正先選択部２０３は、処理を開始すると（ステップＳ２０１）、ステップＳ２０２において、誤差補正を行うかを判定する。補正先選択部２０３は、誤差補正を行うと判定すると（ステップＳ２０２のＹＥＳ）、次にステップＳ２０４を実行し、誤差補正を行わないと判定すると（ステップＳ２０２のＮＯ）、次にステップＳ２０３を実行する。 When the correction destination selection unit 203 starts processing (step S201), it determines in step S202 whether to perform error correction. If the correction destination selection unit 203 determines that error correction is to be performed (YES in step S202), it then executes step S204, and if it determines that error correction is not to be performed (NO in step S202), it then executes step S203.
　ステップＳ２０４において、補正先選択部２０３は、ｄｑ軸電流に対して誤差補正を行なうかを判定する。補正先選択部２０３は、ｄｑ軸電流に対して誤差補正を行うと判定すると（ステップＳ２０４のＹＥＳ）、次にステップＳ２０５を実行し、ｄｑ軸電流に対しては誤差補正を行わないと判定すると（ステップＳ２０３のＮＯ）、次にステップＳ２０６を実行する。 In step S204, the correction destination selection unit 203 determines whether to perform error correction on the d- and q-axis currents. If the correction destination selection unit 203 determines that error correction is to be performed on the d- and q-axis currents (YES in step S204), it next executes step S205, and if it determines that error correction is not to be performed on the d- and q-axis currents (NO in step S203), it next executes step S206.
　ステップＳ２０３において、補正先選択部２０３は、ｄｑ軸電流補正量計算部２０１に対して、Δｉｄｑとして「０」（ベクトル量）を出力するように指令し、また三相電流補正量計算部２０２に対して、ｍｕｖｗとして「１」（ベクトル量）を出力するように指令する。補正先選択部２０３は、ステップＳ２０３を実行すると、一連の処理を終了する（ステップＳ２０７）。 In step S203, the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to output "0" (vector amount) as Δi dq , and instructs the three-phase current correction amount calculation unit 202 to output "1" (vector amount) as m uvw . After executing step S203, the correction destination selection unit 203 ends the series of processes (step S207).
　ステップＳ２０５において、補正先選択部２０３は、ｄｑ軸電流補正量計算部２０１に対して、誤差ｅｒｒｕｖｗを用いてΔｉｄｑを計算して出力するように指令し、また三相電流補正量計算部２０２に対してｍｕｖｗとして「１」（ベクトル量）を出力するように指令する。補正先選択部２０３は、ステップＳ２０５を実行すると、一連の処理を終了する（ステップＳ２０７）。 In step S205, the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to calculate and output Δi dq using the error err uvw , and instructs the three-phase current correction amount calculation unit 202 to output "1" (vector amount) as m uvw . After executing step S205, the correction destination selection unit 203 ends the series of processes (step S207).
　ステップＳ２０６において、補正先選択部２０３は、ｄｑ軸電流補正量計算部２０１に対して、Δｉｄｑとして「０」（ベクトル量）を出力するように指令し、また三相電流補正量計算部２０２に対して、ｅｒｒｕｖｗを用いてｍｕｖｗを計算して出力するように指令する。補正先選択部２０３は、ステップＳ２０６を実行すると、一連の処理を終了する（ステップＳ２０７）。 In step S206, the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to output "0" (vector amount) as Δi dq , and instructs the three-phase current correction amount calculation unit 202 to calculate and output m uvw using err uvw . After executing step S206, the correction destination selection unit 203 ends the series of processes (step S207).
　ステップＳ２０３，Ｓ２０５およびＳ２０６が示すように、本実施例では、誤差補正は、三相電流およびｄｑ軸電流の内の一方のみに対して行われる。これにより、モータ制御装置における誤差補正動作の安定性が向上する。 As shown in steps S203, S205, and S206, in this embodiment, error correction is performed on only one of the three-phase currents and the d- and q-axis currents. This improves the stability of the error correction operation in the motor control device.
　なお、ステップＳ２０４における判定基準は、誤差の推定精度が低下したり、計算負荷が増大したりする場合を考慮して、適宜設定される。ステップＳ２０４における判定基準によっては、三相電流およびｄｑ軸電流の両方に対して、誤差補正を行ってもよい。 The criteria in step S204 are set appropriately, taking into consideration cases where the error estimation accuracy decreases or the calculation load increases. Depending on the criteria in step S204, error correction may be performed on both the three-phase currents and the d- and q-axis currents.
　上述のように、本実施例によれば、三相交流電流振幅値に基づいて電流センサのゲイン誤差が計算され、計算されたゲイン誤差に基づいて三相電流検出値およびｄｑ軸電流検出値の内の一方が補正される。これにより、特別な動作シーケンスを備えることなく、安定かつ正確に電流センサのゲイン誤差を推定・補償できる。 As described above, according to this embodiment, the gain error of the current sensor is calculated based on the three-phase AC current amplitude value, and one of the three-phase current detection values and the dq-axis current detection values is corrected based on the calculated gain error. This makes it possible to stably and accurately estimate and compensate for the gain error of the current sensor without having to provide a special operating sequence.
　なお、本実施例によるモータ制御装置がゲイン誤差の推定・補償を実行するときには、予め電流センサのオフセット誤差が補償されていることが好ましい。電流センサのオフセット誤差補償は、例えば、モータ電流を流していないときの電流センサの出力信号が示す平均的な電流値を、モータ電流検出値から差し引くことにより実施できる。 When the motor control device according to this embodiment estimates and compensates for the gain error, it is preferable that the offset error of the current sensor has been compensated for in advance. The offset error compensation of the current sensor can be performed, for example, by subtracting the average current value indicated by the output signal of the current sensor when no motor current is flowing from the motor current detection value.
　本実施例のモータ制御装置１においては、電流センサ１１のゲイン誤差を補償するための制御部を、誤差推定を実行する誤差計算部１００と、誤差補正を実行する補正量計算部２００とに分けて備えている。これにより、誤差計算部１００を動作させて誤差推定を行った後、補正量計算部２００を動作させて誤差補正を行ってもよい。例えば、モータ５の起動時に、まず誤差計算部１００により誤差を推定し、その後、補正量計算部２００を動作させて、推定された誤差に基づいて誤差補正を行なう。なお、モータ５の起動時毎に誤差推定を行ってもよいし、モータ制御装置１に対して所定操作した場合に、誤差推定を行ってもよい。 In the motor control device 1 of this embodiment, the control unit for compensating for the gain error of the current sensor 11 is divided into an error calculation unit 100 that performs error estimation, and a correction amount calculation unit 200 that performs error correction. As a result, the error calculation unit 100 may be operated to perform error estimation, and then the correction amount calculation unit 200 may be operated to perform error correction. For example, when the motor 5 is started, the error is first estimated by the error calculation unit 100, and then the correction amount calculation unit 200 is operated to perform error correction based on the estimated error. Note that error estimation may be performed every time the motor 5 is started, or when a specified operation is performed on the motor control device 1.
　図７は、本発明の実施例２であるモータ制御装置の構成を示す機能ブロック図である。 FIG. 7 is a functional block diagram showing the configuration of a motor control device according to a second embodiment of the present invention.
　以下、主に、実施例１と異なる点について説明する。 　Below, we will mainly explain the differences from Example 1.
　図７に示すように、本実施例のモータ制御装置１は、電流制御系を有していない。このため、電流センサ１１のゲイン誤差補償のためにｄｑ軸電流検出値は補正されない。 As shown in FIG. 7, the motor control device 1 of this embodiment does not have a current control system. Therefore, the dq-axis current detection values are not corrected to compensate for the gain error of the current sensor 11.
　本実施例のモータ制御装置１は、モータ駆動中に電流制御が行われていないがモータ電流が流れている場合、すなわち、ｄｑ軸電流指令値と実際に流れるｄｑ軸電流とが一致しない場合、例えば、過電圧保護などのためにインバータ４の三相短絡が実行される場合に、動作する。 The motor control device 1 of this embodiment operates when current control is not being performed while the motor is being driven but motor current is flowing, i.e., when the dq-axis current command value and the actual dq-axis current flowing do not match, for example, when a three-phase short circuit of the inverter 4 is performed for overvoltage protection, etc.
　なお、本実施例２のモータ制御装置１の構成は、実施例１（図１）のモータ制御装置において上記の場合に動作する部分である。 The configuration of the motor control device 1 of this embodiment 2 is the part that operates in the above case in the motor control device of embodiment 1 (Figure 1).
　図８は、実施例２における誤差計算部１００（図７）の構成を示す機能ブロック図である。 FIG. 8 is a functional block diagram showing the configuration of the error calculation unit 100 (FIG. 7) in the second embodiment.
　本実施例２における三相電流振幅推定部１０１は、三相モータ電流検出値ｉｍｅａｓｕｖｗ（＝（ｉｍｅａｓｕ，Ｉｍｅａｓｖ，Ｉｍｅａｓｗ））と、電気角θｅおよび電気角速度ωｅ（図７）とに基づくとともに、さらにｄｑ軸電流指令値ｉ＊ｄｑ（図２）に替えてｄｑ軸電流検出値Ｉｄｑ（＝（Ｉｄ，Ｉｑ））に基づいて、三相モータ電流振幅値ＩＵＶＷ（＝（ＩＵ，ＩＶ，ＩＷ）を推定する。 A three-phase current amplitude estimator 101 in the second embodiment estimates three-phase motor current amplitude values I UVW (=(I U , IV , IW )) based on three-phase motor current detection values imeas uvw (=(imeas u , Imeas v , Imeas w )), the electrical angle θ e and the electrical angular velocity ω e ( FIG. 7 ), and further based on a dq-axis current detection value I dq (=(I d , I q )) instead of the dq-axis current command value i* dq ( FIG . 2 ).
　三相電流振幅推定部１０１は、前述の式（５），（７）および（８）に基づいて三相モータ電流振幅値ＩＵＶＷを計算する。ただし、回転座標系における電流位相βｃは、式（１５）を用いて、ｄｑ軸電流検出値ｉｄｑから計算される。 The three-phase current amplitude estimation unit 101 calculates the three-phase motor current amplitude values I UVW based on the above-mentioned equations (5), (7), and (8), where the current phase β c in the rotating coordinate system is calculated from the d-axis and q-axis current detection values i dq using equation (15).
Figure JPOXMLDOC01-appb-M000015
Figure JPOXMLDOC01-appb-M000015
　本実施例２におけるモータ状態判定部１０３は、ｄｑ軸電流指令値ｉ＊ｄｑ（図２）に替えてｄｑ軸電流検出値ｉｄｑを用いて、モータ５（図７）の状態を判定する。 The motor state determination unit 103 in the second embodiment determines the state of the motor 5 (FIG. 7) by using the dq-axis current detection values i dq instead of the dq-axis current command values i* dq (FIG. 2).
　図９は、実施例２における補正量計算部２００（図７）の構成を示す機能ブロック図である。 FIG. 9 is a functional block diagram showing the configuration of the correction amount calculation unit 200 (FIG. 7) in the second embodiment.
　本実施例２におけるｄｑ軸電流補正量計算部２０１は、誤差計算部１００（図８）によって計算された誤差ｅｒｒｕｖｗ（＝（ｅｒｒｕ，ｅｒｒｖ，ｅｒｒｗ））と、機械角θｅ（図７）とに基づくとともに、ｄｑ軸電流指令値ｉ＊ｄｑ（図３）に替えてｄｑ軸電流検出値ｉｄｑに基づいて、ｄｑ軸電流補正量Δｉｄｑ（＝（Δｉｄ，Δｉｑ））を計算する。 The dq-axis current correction amount calculation unit 201 in this embodiment 2 calculates the dq-axis current correction amount Δi dq (=(Δi d , Δi q )) based on the error err uvw (=(err u , err v , err w ) ) calculated by the error calculation unit 100 (FIG. 8) and the mechanical angle θ e (FIG. 7), and also based on the dq-axis current detection value i dq instead of the dq-axis current command value i* dq (FIG. 3 ).
　図１０は、補正先選択部３０３の動作を示すフローチャートである。 FIG. 10 is a flowchart showing the operation of the correction destination selection unit 303.
　図１０に示すステップＳ３０１，Ｓ３０３，Ｓ３０４，Ｓ３０５，Ｓ３０６，Ｓ３０７およびＳ３０８は、それぞれ、前述の図６（実施例１）におけるステップＳ２０１，Ｓ２０２，Ｓ２０４，Ｓ２０５，Ｓ２０６，Ｓ２０３およびＳ２０７に相当する。 Steps S301, S303, S304, S305, S306, S307, and S308 shown in FIG. 10 correspond to steps S201, S202, S204, S205, S206, S203, and S207 in FIG. 6 (Example 1), respectively.
　本実施例２において、補正先選択部３０３は、処理を開始すると（ステップＳ３０１）、ステップＳ３０２において、電流制御が有効であるかを判定する。本実施例２においては、電流制御が実行されないので、補正先選択部３０３は、電流制御は有効ではないと判定し（ステップＳ３０２のＮＯ）、次にステップＳ３０６を実行する。 In this embodiment 2, when the correction destination selection unit 303 starts processing (step S301), it determines in step S302 whether current control is enabled. In this embodiment 2, since current control is not executed, the correction destination selection unit 303 determines that current control is not enabled (NO in step S302) and then executes step S306.
　ステップＳ３０６において、補正先選択部２０３は、ｄｑ軸電流補正量計算部２０１に対して、Δｉｄｑとして「０」（ベクトル量）を出力するように指令し、また三相電流補正量計算部２０２に対して、ｅｒｒｕｖｗを用いてｍｕｖｗを計算して出力するように指令する。補正先選択部３０３は、ステップＳ３０６を実行すると、一連の処理を終了する（ステップＳ３０８）。 In step S306, the correction destination selection unit 203 instructs the dq-axis current correction amount calculation unit 201 to output "0" (vector amount) as Δi dq , and instructs the three-phase current correction amount calculation unit 202 to calculate and output m uvw using err uvw . After executing step S306, the correction destination selection unit 303 ends the series of processes (step S308).
　本実施例２によれば、三相交流電流振幅値に基づいて電流センサのゲイン誤差が計算され、計算されたゲイン誤差に基づいて三相電流検出値が補正される。これにより、特別な動作シーケンスを備えることなく、安定かつ正確に電流センサのゲイン誤差を推定・補償できる。これにより、インバータ４の三相短絡動作時のようにモータ駆動中に電流制御が行われていないがモータ電流が流れている場合でも、特別な動作シーケンスを備えることなく、安定かつ正確に電流センサのゲイン誤差を推定・補償できる。 According to the second embodiment, the gain error of the current sensor is calculated based on the three-phase AC current amplitude value, and the three-phase current detection value is corrected based on the calculated gain error. This allows the current sensor gain error to be estimated and compensated for stably and accurately without a special operating sequence. This allows the current sensor gain error to be estimated and compensated for stably and accurately without a special operating sequence, even when no current control is performed during motor drive but motor current is flowing, such as during three-phase short-circuit operation of the inverter 4.
　なお、本発明は前述した実施形態に限定されるものではなく、様々な変形例が含まれる。例えば、前述した実施形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、各実施形態の構成の一部について、他の構成の追加・削除・置き換えをすることが可能である。 The present invention is not limited to the above-described embodiments, but includes various modified examples. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described. In addition, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.
１　モータ制御装置、２　ｄｑ軸電流指令値、３　制御器、４　インバータ、５　モータ、６　電気角計算部、７　電気角速度計算部、８　Ａ／Ｄ変換器、９　三相／ｄｑ軸変換器、１０ａ　ｄｑ軸電流補正部、１０ｂ　三相電流補正部、１００　誤差計算部、２００　補正量計算部、１０１　三相電流振幅推定部、１０２　誤差推定部、１０３　モータ状態判定部、２０１　ｄｑ軸電流補正量計算部、２０２　三相電流補正量計算部、２０３　補正先選択部、３０３　補正先選択部。 1 Motor control device, 2 dq axis current command value, 3 Controller, 4 Inverter, 5 Motor, 6 Electrical angle calculation unit, 7 Electrical angular velocity calculation unit, 8 A/D converter, 9 Three-phase/dq axis converter, 10a dq axis current correction unit, 10b Three-phase current correction unit, 100 Error calculation unit, 200 Correction amount calculation unit, 101 Three-phase current amplitude estimation unit, 102 Error estimation unit, 103 Motor state determination unit, 201 dq axis current correction amount calculation unit, 202 Three-phase current correction amount calculation unit, 203 Correction destination selection unit, 303 Correction destination selection unit.

Claims (13)

  1. 　交流モータを駆動するインバータの制御信号を生成するモータ制御装置において、
    　電流センサによって検出される三相モータ電流の振幅値を用いて前記電流センサのゲイン誤差を計算する誤差計算部と、
    　前記誤差計算部によって推定される前記ゲイン誤差に基づいて、前記ゲイン誤差を補償するための電流補正量を計算する補正量計算部と、
    を備えることを特徴とするモータ制御装置。     2. A motor control device that generates a control signal for an inverter that drives an AC motor,
    an error calculation unit that calculates a gain error of the current sensor using an amplitude value of a three-phase motor current detected by the current sensor;
    a correction amount calculation unit that calculates a current correction amount for compensating for the gain error based on the gain error estimated by the error calculation unit;
    A motor control device comprising:
  2. 　請求項１に記載のモータ制御装置において、
    　前記誤差計算部は、前記三相モータ電流の各相の前記振幅値と、三相の前記振幅値の平均値とに基づいて、前記ゲイン誤差を計算することを特徴とするモータ制御装置。     2. The motor control device according to claim 1,
    The motor control device according to claim 1, wherein the error calculation unit calculates the gain error based on the amplitude value of each phase of the three-phase motor current and an average value of the amplitude values of the three phases.
  3. 　請求項２に記載のモータ制御装置において、
    　前記誤差計算部は、前記三相モータ電流の検出値と、前記交流モータの電気角および電気角速度と、ｄｑ軸電流の指令値とに基づいて、前記三相モータ電流の前記各相の前記振幅値を推定することを特徴とするモータ制御装置。     3. The motor control device according to claim 2,
    the error calculation unit estimates the amplitude values of the respective phases of the three-phase motor current based on detection values of the three-phase motor current, an electrical angle and an electrical angular velocity of the AC motor, and command values of dq-axis currents.
  4. 　請求項１に記載のモータ制御装置において、
    　前記誤差計算部は、前記交流モータの電流位相量の時間変化率が所定値以下であるときに、前記ゲイン誤差の計算を実施することを特徴とするモータ制御装置。     2. The motor control device according to claim 1,
    The motor control device according to claim 1, wherein the error calculation unit calculates the gain error when a time rate of change of a current phase amount of the AC motor is equal to or smaller than a predetermined value.
  5. 　請求項１に記載のモータ制御装置において、
    　前記補正量計算部は、前記三相モータ電流の検出値を補正する三相電流補正量と、ｄｑ軸電流の検出値を補正するｄｑ軸電流補正量を計算することを特徴とするモータ制御装置。     2. The motor control device according to claim 1,
    The motor control device according to claim 1, wherein the correction amount calculation unit calculates a three-phase current correction amount for correcting a detection value of the three-phase motor current, and a dq-axis current correction amount for correcting a detection value of a dq-axis current.
  6. 　請求項５に記載のモータ制御装置において、
    　前記補正量計算部は、前記三相電流補正量として、前記ゲイン誤差に基づいて、補正係数を計算し、
    　前記補正量計算部は、前記ゲイン誤差と、前記交流モータの電気角と、前記ｄｑ軸電流の指令値に基づいて、前記ｄｑ軸電流補正量を計算することを特徴とするモータ制御装置。     6. The motor control device according to claim 5,
    the correction amount calculation unit calculates a correction coefficient as the three-phase current correction amount based on the gain error;
    The motor control device according to claim 1, wherein the correction amount calculation unit calculates the dq-axis current correction amounts based on the gain error, an electrical angle of the AC motor, and command values of the dq-axis currents.
  7. 　請求項５に記載のモータ制御装置において、
    　前記補正量計算部は、前記三相電流補正量および前記ｄｑ軸電流補正量のいずれか一方を選択する選択部を備えることを特徴とするモータ制御装置。     6. The motor control device according to claim 5,
    The motor control device according to claim 1, wherein the correction amount calculation unit includes a selection unit that selects either the three-phase current correction amount or the dq-axis current correction amount.
  8. 　請求項５に記載のモータ制御装置において、
    　前記三相電流補正量によって補正された前記三相モータ電流の前記検出値を前記ｄｑ軸電流の前記検出値に変換することを特徴とするモータ制御装置。     6. The motor control device according to claim 5,
    a detection value of the three-phase motor current corrected by the three-phase current correction amount is converted into a detection value of the dq-axis current.
  9. 　請求項５に記載のモータ制御装置において、
    　前記ｄｑ軸電流補正量によって補正された前記ｄｑ軸電流の前記検出値と、前記ｄｑ軸電流の指令値とに基づいて、前記制御信号を生成する制御器を備えることを特徴とするモータ制御装置。     6. The motor control device according to claim 5,
    A motor control device comprising: a controller that generates the control signal based on the detection values of the dq-axis currents corrected by the dq-axis current correction amounts and command values of the dq-axis currents.
  10. 　請求項２に記載のモータ制御装置において、
    　ｄｑ軸電流の指令値と前記ｄｑ軸電流の検出値とが一致しないモータ動作では、
    　前記誤差計算部は、前記三相モータ電流の検出値と、前記交流モータの電気角および電気角速度と、前記ｄｑ軸電流の前記検出値とに基づいて、前記三相モータ電流の前記各相の前記振幅値を推定することを特徴とするモータ制御装置。     3. The motor control device according to claim 2,
    In the motor operation where the command value of the dq axis current does not match the detected value of the dq axis current,
    the error calculation unit estimates the amplitude values of the respective phases of the three-phase motor current based on the detected values of the three-phase motor current, the electrical angle and electrical angular velocity of the AC motor, and the detected values of the dq-axis currents.
  11. 　請求項１０に記載のモータ制御装置において、
    　前記補正量計算部は、前記三相モータ電流の前記検出値を補正する三相電流補正量と、前記ｄｑ軸電流の前記検出値を補正するｄｑ軸電流補正量を計算することを特徴とするモータ制御装置。     11. The motor control device according to claim 10,
    The motor control device according to claim 1, wherein the correction amount calculation unit calculates a three-phase current correction amount for correcting the detected value of the three-phase motor current, and a dq-axis current correction amount for correcting the detected value of the dq-axis current.
  12. 　請求項１１に記載のモータ制御装置において、
    　前記ｄｑ軸電流の前記指令値と前記ｄｑ軸電流の前記検出値とが一致しない前記交流モータの動作では、
    　前記補正量計算部は、前記三相電流補正量として、前記ゲイン誤差に基づいて、補正係数を計算し、
    　前記補正量計算部は、前記ゲイン誤差と、前記モータの電気角と、前記ｄｑ軸電流の前記検出値に基づいて、前記ｄｑ軸電流補正量を計算することを特徴とするモータ制御装置。     12. The motor control device according to claim 11,
    In an operation of the AC motor in which the command value of the dq-axis current does not match the detected value of the dq-axis current,
    the correction amount calculation unit calculates a correction coefficient as the three-phase current correction amount based on the gain error;
    The motor control device according to claim 1, wherein the correction amount calculation unit calculates the dq-axis current correction amounts based on the gain error, the electrical angle of the motor, and the detected values of the dq-axis currents.
  13. 　請求項１２に記載のモータ制御装置において、
    　前記補正量計算部は、前記三相電流補正量および前記ｄｑ軸電流補正量の内、前記三相電流補正量を選択する選択部を備えることを特徴とするモータ制御装置。     13. The motor control device according to claim 12,
    The motor control device according to claim 1, wherein the correction amount calculation unit includes a selection unit that selects the three-phase current correction amount from among the three-phase current correction amount and the dq-axis current correction amount.
PCT/JP2023/033547 2022-09-28 2023-09-14 Motor control device WO2024070731A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07274411A (en) * 1994-03-30 1995-10-20 Mitsubishi Electric Corp Power generation controller for vehicle
JP2011078295A (en) * 2008-10-30 2011-04-14 Denso Corp Motor control device of vehicle
JP2013219988A (en) * 2012-04-12 2013-10-24 Denso Corp Control device of rotating machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07274411A (en) * 1994-03-30 1995-10-20 Mitsubishi Electric Corp Power generation controller for vehicle
JP2011078295A (en) * 2008-10-30 2011-04-14 Denso Corp Motor control device of vehicle
JP2013219988A (en) * 2012-04-12 2013-10-24 Denso Corp Control device of rotating machine

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