JP4735287B2 - Synchronous motor control device and control method using the synchronous motor control device - Google Patents

Description

  The present invention relates to a control device for a synchronous motor and a control method using the control device for the synchronous motor.

[Conventional technology]
2. Description of the Related Art In recent years, sensorless control methods for estimating magnetic pole positions have been widespread in synchronous motor control devices (hereinafter simply referred to as control devices) instead of position sensors that directly detect magnetic pole positions. One of the sensorless control methods is a so-called disturbance injection method.

  This disturbance injection method is a high-frequency disturbance in which a command value for estimation for estimating a magnetic pole position is added to a command value for driving calculated in accordance with an operation condition (for example, required output torque) of a synchronous motor. Are added to obtain the final command value, and the final command value is used to control the synchronous motor and estimate the magnetic pole position.

  For example, a disturbance injection type control device adds an estimation voltage vector consisting of an estimation voltage command value as a high-frequency disturbance to a driving voltage vector obtained by converting a command value of a driving voltage into an axis component. Thus, a final command voltage vector is used, and a PWM signal for applying a voltage to the synchronous motor is synthesized based on the command voltage vector and is output to a predetermined inverter. Then, the disturbance injection control device estimates the magnetic pole position according to various fluctuations caused by the addition of the estimation voltage vector (see, for example, Patent Documents 1 to 3).

  For example, according to the technique described in Patent Document 1, a current vector obtained by converting the amount of current supplied to the synchronous motor into an axial component is converted into a vector perpendicular to the estimation voltage vector and parallel to the estimation voltage vector. The magnetic pole position is estimated based on one of these vectors. Further, according to the technique described in Patent Document 2, the magnetic pole position is estimated based on the temporal change amount of the current vector.

  Furthermore, according to the technique described in Patent Document 3, the amount of change in the current vector generated based on the first command voltage vector obtained by adding one estimation voltage vector (first estimation voltage vector) to the driving voltage vector ( A first current change amount vector) and a change amount of a current vector (second current change amount) generated based on a second command voltage vector obtained by adding an estimation voltage vector different from the first estimation voltage vector to the drive voltage vector Vector) and the magnetic pole position is estimated so that the magnitude of the first current variation vector and the magnitude of the second current variation vector are substantially the same.

[Problems with conventional technology]
However, according to these techniques, it is necessary to repeat mathematical operations using trigonometric functions and inverse trigonometric functions at a high frequency in the process of estimating the magnetic pole position, and the processing load on the control device is extremely large.
Japanese Patent No. 3312472 Japanese Patent No. 3454212 Japanese Patent No. 3578096

  The present invention has been made to solve the above-described problems, and an object thereof is to reduce a processing load when estimating a magnetic pole position in a synchronous motor control device.

[Means of Claims 1 and 2 ]
The control device according to claim 1 is a control device for a synchronous motor having saliency, wherein a command voltage vector is obtained by adding an estimation voltage vector for estimating a magnetic pole position to a drive motor voltage vector. The voltage applied to the synchronous motor is controlled based on the command voltage vector. Then, the control device includes a detection current vector calculation means for calculating a detection current vector corresponding to the detection value based on a detection value of the energization amount to the synchronous motor, and an estimation voltage vector of the detection current vector. An estimation current vector calculation unit that calculates a portion generated by the addition as an estimation current vector, and a magnetic pole position estimation unit that estimates a magnetic pole position based on an outer product of the estimation voltage vector and the estimation current vector.
Further, the estimation voltage vector is calculated so as to be parallel to the estimated magnetic pole position and the vector direction is repeatedly inverted, and the magnetic pole position estimation means calculates the estimation voltage vector and the estimation current vector. The magnetic pole position is estimated so that the outer product substantially matches zero.
According to the control device of the second aspect, the magnetic pole position estimation means estimates the magnetic pole rotation speed so that the outer product of the estimation voltage vector and the estimation current vector substantially matches zero, and the magnetic pole rotation speed The magnetic pole position is estimated using the estimated value.

  Obtaining the direction of the command voltage vector with respect to the true magnetic pole position (that is, the direction in which the voltage is applied: the applied voltage phase θv, hereinafter referred to as voltage phase θv) corresponds to estimating the magnetic pole position. In the present invention, in order to estimate the magnetic pole position for a synchronous motor having saliency, first, the positive / negative of the voltage / current phase difference (that is, the angle difference between the voltage vector and the current vector: hereinafter referred to as the phase difference θvi). Note that the positive and negative of the voltage phase θv shows an inverse correlation.

That is, according to the present invention, if the phase difference θvi is zero, the voltage phase θv is zero, if the phase difference θvi is a positive value, the voltage phase θv is a negative value, and the phase difference θvi is a negative value. Note that the voltage phase θv is a positive value if any.
The inverse correlation between the positive / negative of the phase difference θvi and the positive / negative of the voltage phase θv can be derived as follows when the synchronous motor having saliency is sensorlessly controlled by the disturbance injection method.

First, the voltage equation in the case of controlling the synchronous motor by the disturbance injection method is expressed by the following Equation 1 when expressed by the dq axis component of the rotating coordinate system.
[Formula 1]

  In Equation 1, vd is the d-axis component of the drive voltage vector, vq is the q-axis component of the drive voltage vector, vhd is the d-axis component of the estimation voltage vector, vhq is the q-axis component of the estimation voltage vector, R Is the winding resistance of the armature coil, p is the differential operator, ω is the angular velocity (corresponding to the number of magnetic pole rotations), φa is the flux linkage of the magnet, Ld is the d-axis inductance, Lq is the q-axis inductance, and id is the drive The d-axis component of the current vector resulting from the voltage vector for use (referred to as the drive current vector), iq the q-axis component of the drive current vector, and ihd the current vector resulting from the voltage vector for estimation (referred to as the estimation current vector) ) D-axis component, ihq is the q-axis component of the estimation current vector.

Then, in Equation 1, only the portion corresponding to the estimation voltage vector and the estimation current vector is taken into account only in consideration of the high frequency, and the differential operator p is expressed using the sampling period Δt, the following Equation 2 become that way.
[Formula 2]

Next, when the dq axis components vhd and vhq of the estimation voltage vector are expressed using the voltage phase θv, the following Equation 3 is obtained. In Equation 3, va is the magnitude of the estimation voltage vector.
[Formula 3]

By applying Equation 3 to Equation 2 and solving for the dq-axis components ihd and ihq of the estimation current vector, Equation 4 below is obtained.
[Formula 4]

Further, the current phase θi is expressed by Equation 5 below using the dq axis components ihd and ihq of the estimation current vector.
[Formula 5]

Therefore, the phase difference θvi can be transformed as shown in Equation 6 below.
[Formula 6]

Here, assuming that the voltage phase θv is a minute value, the final expression in Expression 6 can be transformed as Expression 7 below.
[Formula 7]

When the synchronous motor has saliency, since the d-axis inductance Ld is smaller than the q-axis inductance Lq, (Ld / Lq−1) in Equation 7 is always a negative value.
As described above, in the case of a synchronous motor having saliency, the positive / negative of the phase difference θvi and the positive / negative of the voltage phase θv show an inverse correlation.

  Next, the present invention focuses on the outer product (hereinafter referred to as outer product V × I) of the estimation voltage vector and the estimation current vector. Since the outer product V × I is defined as the product of the magnitude of the estimation voltage vector, the magnitude of the estimation current vector, and the sine function of the phase difference θvi, the outer product V × I and the phase difference θvi Positive and negative indicate forward correlation. That is, if the outer product V × I is zero, the phase difference θvi is zero, if the outer product V × I is a positive value, the phase difference θvi is a positive value, and the outer product V × I is a negative value. For example, the phase difference θvi is a negative value.

  Therefore, when the sign of the outer product V × I and the sign of the phase difference θvi indicate a forward correlation, and the sign of the phase difference θvi and the sign of the voltage phase θv indicate an inverse correlation, the outer product V × I It can be seen that the positive / negative sign of the voltage phase and the positive / negative sign of the voltage phase θv show an inverse correlation. For this reason, the sign of the voltage phase θv can be estimated from the sign of the outer product V × I.

Further, the outer product V × I can be calculated by simple four arithmetic operations using each component of the estimation voltage vector and the estimation current vector without directly using the phase difference θvi as defined above. it can. For example, if the estimation voltage vector is represented by αβ axis components vhα and vhβ of the stationary coordinate system, and the estimation current vector is also represented by αβ axis components ihα and ihβ, the outer product V × I can be calculated by the following Equation 8.
[Formula 8]

As described above, the sign of the voltage phase θv can be estimated according to the sign of the outer product V × I that can be calculated by simple four arithmetic operations. For this reason, when estimating the magnetic pole position, the frequency of using the trigonometric function and the inverse trigonometric function can be lowered, so that the processing load on the control device can be reduced.
In the means of claims 1 and 2 , the injected disturbance is an estimation voltage vector, and the estimation current vector is calculated based on the detected current vector.
In addition, since the estimation voltage vector is calculated so as to be parallel to the estimated magnetic pole position, even if the estimation voltage vector is added to the driving voltage vector, output torque corresponding to the estimation voltage vector is generated. do not do. For this reason, even if the estimation voltage vector is added to the driving voltage vector, an output torque corresponding to only the driving voltage vector can be obtained.
Further, according to the control device of the first and second aspects, the magnetic pole position estimation means performs estimation so that the outer product of the estimation voltage vector and the estimation current vector is substantially equal to zero. Since the outer product V × I is the target to be substantially matched with the above, the influence of the winding resistance R of the armature coil, the linkage flux φa of the magnet, the d-axis inductance Ld, and the q-axis inductance Lq is excluded when performing the convergence calculation. be able to. For this reason, when the convergence calculation is performed, the influence of the use conditions of the synchronous motor such as temperature can be excluded.

[Means of claim 3 ]
According to the control device of the third aspect , the outer product of the estimation voltage vector and the estimation current vector is obtained by calculating an estimation voltage vector composed of a stationary coordinate system component and an estimation current vector composed of a stationary coordinate system component. Is calculated using
This means shows one form of the calculation method of the outer product V × I.

[Means of claim 4 ]
According to the control device of the fourth aspect , the outer product of the estimation voltage vector and the estimation current vector is obtained by calculating the estimation voltage vector composed of the rotational coordinate system components and the estimation current vector composed of the rotational coordinate system components. Is calculated using
This means shows one form of the calculation method of the outer product V × I.

[Means of claim 5 ]
According to the control device of the fifth aspect , the magnetic pole position estimating means varies the parameter used when estimating the magnetic pole position according to the estimated value of the magnetic pole rotation number calculated using the estimated value of the magnetic pole position. To do.
This means relates to the magnetic pole position estimating means described in claim 1 . According to this means, for example, the parameters such as the proportional gain and the integral gain when the PI operation is performed on the outer product V × I can be changed to the direction in which the outer product V × I substantially coincides with zero earlier. it can. For this reason, the magnetic pole position can be estimated earlier.

[Means of claim 6 ]
According to the control device of the sixth aspect , the magnetic pole position estimating means varies the parameter used when estimating the magnetic pole rotation speed according to the estimated value of the magnetic pole rotation speed.
This means relates to the magnetic pole position estimating means described in claim 2 . According to this means, the same effect as that of the means of claim 5 can be obtained.

[Means of Claim 7 ]
According to the control device of the seventh aspect , the magnetic pole position estimating means calculates the estimated value of the magnetic pole position when the positive / negative of the command value of the energization amount is different from the positive / negative of the rate of change of the estimated value of the magnetic pole rotation speed. Change by changing π.
As a result, the estimated NS of the magnetic pole can be reversed when the direction in which the control device wants to rotate the magnetic pole is opposite to the direction in which the magnetic pole tries to rotate in response to a command from the control device. For this reason, rotation stop and reverse rotation of the synchronous motor can be prevented.

[Means of Claim 8 ]
According to an eighth aspect of the present invention, the control device includes voltage limiting means for correcting the drive voltage vector so that the applied voltage is equal to or lower than the power supply voltage.
As a result, the estimation voltage can be reliably applied, so that the magnetic pole position can be reliably estimated. For this reason, the reliability of a control apparatus can be improved.

[Means of Claim 9 ]
According to the control device of the ninth aspect , the magnetic pole position estimation means determines the fluctuation period of the portion of the applied voltage based on the estimation voltage vector based on the random number.
Thereby, since the frequency of the voltage for estimation can be disperse | distributed, the noise accompanying application of the voltage for drive can be reduced.

[Means of Claim 10 ]
According to the control method of the tenth aspect , the magnetic pole position is estimated at a predetermined time after the start of the synchronous motor, and the applied voltage is set so as to reach magnetic saturation in both the positive direction and the negative direction of the estimated magnetic pole position. The magnetic poles are determined according to the energization amount when the magnetic saturation is reached in the positive direction and the energization amount when the magnetic saturation is reached in the negative direction.
Accordingly, it is possible to estimate the magnetic pole position and perform NS determination within an extremely short time after the start of the synchronous motor. For this reason, sensorless control can be performed very early after the synchronous motor is started.

[Means of Claim 11 ]
The control device according to claim 11 sets a target value for the magnitude of the energization amount, and when the energization amount is smaller than the target value, the magnitude of the energization amount substantially matches the target value. Thus, the reactive current increasing means for increasing the command value of the d-axis current is provided.
When the amount of current supplied to the synchronous motor is small, the difference (inductance difference) between the q-axis inductance Lq and the d-axis inductance Ld is small, so that the estimation of the magnetic pole position becomes difficult and the error increases. Therefore, the target value is set with respect to the magnitude of the energization amount in consideration of the allowable range of error. When the energization amount is smaller than the target value, the magnitude of the energization amount is increased to the target value to increase the inductance difference. At this time, by increasing only the d-axis current, the amount of energization can be increased without affecting the output torque.

[Means of Claim 12 ]
According to the control device of the twelfth aspect , the synchronous motor is a vehicle motor mounted on the vehicle.

  The control device of the best mode 1 is a control device for a synchronous motor having saliency, and a command voltage vector is obtained by adding an estimation voltage vector for estimating a magnetic pole position to a drive voltage vector for the synchronous motor. The voltage applied to the synchronous motor is controlled based on the command voltage vector. Then, the control device includes a detection current vector calculation means for calculating a detection current vector corresponding to the detection value based on a detection value of the energization amount to the synchronous motor, and an estimation voltage vector of the detection current vector. An estimation current vector calculation unit that calculates a portion generated by the addition as an estimation current vector, and a magnetic pole position estimation unit that estimates a magnetic pole position based on an outer product of the estimation voltage vector and the estimation current vector.

The outer product of the estimation voltage vector and the estimation current vector is calculated using an estimation voltage vector composed of a stationary coordinate system component and an estimation current vector composed of a stationary coordinate system component.
The estimation voltage vector is calculated so that it is parallel to the estimated magnetic pole position and the vector direction repeats reversal .

  The magnetic pole position estimation means estimates the magnetic pole position so that the outer product of the estimation voltage vector and the estimation current vector substantially matches zero. Further, the magnetic pole position estimation means varies a parameter used when estimating the magnetic pole position according to the estimated value of the magnetic pole rotation number calculated using the estimated value of the magnetic pole position.

The magnetic pole position estimating means corrects the estimated value of the magnetic pole position by π when the positive / negative sign of the command value of the energization amount is different from the positive / negative of the change rate of the estimated value of the magnetic pole rotation speed.
The control device further includes voltage limiting means for correcting the driving voltage vector so that the applied voltage is equal to or lower than the power supply voltage.

Then, according to the control method using this control device, the magnetic pole position is estimated at a predetermined time after the start of the synchronous motor, and is applied so as to reach magnetic saturation in both the positive and negative directions of the estimated magnetic pole position. A voltage is applied, and the magnetic pole is determined according to the energization amount when magnetic saturation is reached in the positive direction and the energization amount when magnetic saturation is reached in the negative direction.
The synchronous motor controlled by the control device is a vehicle motor mounted on the vehicle.

According to the control device of the best mode 2, the outer product of the estimation voltage vector and the estimation current vector is obtained by calculating the estimation voltage vector composed of the rotational coordinate system components and the estimation current vector composed of the rotational coordinate system components. Is used to calculate.
Further, the magnetic pole position estimating means determines a fluctuation period of a portion based on the estimation voltage vector in the applied voltage based on a random number.

  According to the control device of the best mode 3, the magnetic pole position estimation means estimates the magnetic pole rotation speed so that the outer product of the estimation voltage vector and the estimation current vector substantially matches zero, and the estimated value of the magnetic pole rotation speed Is used to estimate the magnetic pole position. Further, the magnetic pole position estimating means varies a parameter used when estimating the magnetic pole rotation speed according to the estimated value of the magnetic pole rotation speed.

  The control device of the best mode 4 sets a target value with respect to the magnitude of the energization amount. When the magnitude of the energization amount is smaller than the target value, the magnitude of the energization amount substantially matches the target value. And a reactive current increasing means for increasing the command value of the d-axis current.

[Configuration of Example 1]
The control apparatus 1 of Example 1 is demonstrated based on FIG.
First, the synchronous motor 2 controlled by the control device 1 will be described. The synchronous motor 2 is provided in a stator (not shown) and receives a plurality of phases (for example, three phases of u phase, v phase, and w phase) that receive power from a predetermined power source (not shown). 1) and a magnet (not shown) mounted on the rotor (not shown), and the rotor is rotationally driven to obtain output torque. That is, the synchronous motor 2 receives an AC voltage applied from the inverter 3 to the armature coil, thereby generating an interaction between the armature coil and the magnet and rotationally driving the rotor to obtain an output torque.

  The synchronous motor 2 has a saliency that the d-axis inductance Ld is smaller than the q-axis inductance Lq with respect to the d-axis inductance Ld and the q-axis inductance Lq indicated by the value of the dq-axis component of the rotating coordinate system. The synchronous motor 2 is, for example, a vehicle motor mounted on a vehicle, and is applied to a compressor of a car air conditioner, a motor generator of a hybrid car, and the like.

  The inverter 3 includes upper and lower two-stage transistors (not shown) corresponding to each phase armature coil, that is, six transistors. These transistors receive PWM signals from the control device 1. Operate. As a result, the inverter 3 converts a DC voltage supplied from a predetermined power source into an AC voltage, and applies a voltage having a different phase for each armature coil. As a result, an alternating current is passed through the armature coil, an interaction is generated between the armature coil and the magnet, and the rotor is driven to rotate to generate an output torque.

  Here, the amount of energization to the synchronous motor 2 is detected by the current detection unit 4. The current detection unit 4 includes a current detection sensor (not shown) that is mounted on at least two of the three wires that connect the inverter 3 and each phase armature coil. This current detection sensor detects an energization amount in a non-contact manner with respect to the wiring, for example, like a CT type current sensor. The detected values iu and iv of the energization amount are output to the control device 1 as detection signals.

  The control device 1 is a computer having a well-known structure, and receives input of detection values iu, iv and the like of energization amounts, and applies a voltage to each phase armature coil based on these detection values and various command values. Are combined and output to the inverter 3.

  Thus, the control device 1 controls the power supply to the armature coil to rotationally drive the rotor, and estimates the rotational position of the rotor (hereinafter referred to as the magnetic pole position) according to the power supply state to the armature coil. The power supply to the armature coil is controlled according to the estimated value of the magnetic pole position. That is, the control device 1 employs a sensorless control system that controls the synchronous motor 2 by estimating the magnetic pole position without using the position sensor that detects the magnetic pole position.

Further, the control device 1 applies the estimation voltage for estimating the magnetic pole position as a disturbance to the driving voltage applied according to the operation condition (for example, required output torque) of the synchronous motor 2 and applies it. Thus, sensorless control is performed by a disturbance injection method for estimating the magnetic pole position.
Hereinafter, the control device 1 will be described using the control block flow shown in FIG.

  First, the control device 1 includes a current command generation unit 8 that calculates a command value of the energization amount to the synchronous motor 2 according to the required output torque, and a synchronous motor according to the deviation of the detected current value from the current command value. 2 includes a function of a current control unit 10 that calculates a command value of a driving voltage to be applied to 2 and a voltage limiting unit 11 that limits and corrects the command value of the driving voltage.

  The current command generation unit 8 includes a command value for the energization amount to the synchronous motor 2 in accordance with the required output torque (torque command value τ *) consisting of dq axis components id * and iq * of the rotating coordinate system. Calculated as a command current vector (id *, iq *).

  The current control unit 10 converts the command value of the driving voltage into the dq axis component vd *, dq axis component of the rotational coordinate system according to the deviation vector of the detected current vector (id, iq) with respect to the command current vector (id *, iq *). It is calculated as a driving voltage vector (vd *, vq *) consisting of vq *.

  The detected current vector (id, iq) is obtained by converting the detected values iu and iv of the energization amount detected by the current detection unit 4 into αβ axis components iα and iβ of the stationary coordinate system by the coordinate conversion unit 14. Is a vector obtained by further converting the detected current vector (iα, iβ) obtained by the above into the dq axis components id, iq of the rotating coordinate system by the coordinate conversion unit 15. That is, the coordinate conversion units 14 and 15 are configured as a function of the control device 1, and based on the detected values iu and iv of the energization amount, detected current vectors (iα, iβ), (id, The detection current vector calculation means for calculating iq) is provided. In addition, the estimated value θ of the magnetic pole position, which will be described later, is used for the conversion from the αβ-axis component iα, iβ to the dq-axis component id, iq in the coordinate conversion unit 15.

  The voltage limiting unit 11 limits the magnitude of the driving voltage vector (vd *, vq *) based on the input from the modulation factor monitoring unit 16 to be described later, thereby driving voltage vector (vd *, vq *). Correct. Since the input from the modulation rate monitoring unit 16 is performed when the command value of the modulation rate of the PWM signal exceeds 100%, the correction by the voltage limiting unit 11 is 100% of the command value of the modulation rate of the PWM signal. It is done when exceeding.

  Further, the control device 1 adds an estimation voltage vector (vhα *, vhβ *), which will be described later, to the driving voltage vector (vα *, vβ *) as a high-frequency disturbance, so that a command voltage vector (vα * + vhα *, (vβ * + vhβ *). The drive voltage vectors (vα *, vβ *) are the dq axis components vd *, vq * of the drive voltage vectors (vd *, vq *), and the αβ axis component vα of the stationary coordinate system by the coordinate conversion unit 19. *, A vector obtained by converting to vβ *. Then, in the conversion from the dq axis components vd * and vq * to the αβ axis components vα * and vβ * in the coordinate conversion unit 19, an estimated value θ of the magnetic pole position described later is used.

  Then, the control device 1 converts the command voltage vector (vα * + vhα *, vβ * + vhβ *) into the command values vu *, vv *, vw * of the three-phase applied voltage in the coordinate conversion unit 20, and The modulation factor generation unit 22 calculates a command value for the modulation factor of the PWM signal to be output to the inverter 3 based on the command values vu *, vv *, vw * and the detected value Vdc of the power supply voltage. Then, the control device 1 synthesizes a PWM signal based on the command value of the modulation factor in the PWM synthesizer 23 and outputs it to the inverter 3.

  The control device 1 also includes a function of the modulation rate monitoring unit 16 that monitors whether or not the modulation rate command value calculated by the modulation rate generation unit 22 exceeds 100%. The modulation rate monitoring unit 16 outputs an excess amount from 100% to the voltage limiting unit 11 when the command value of the modulation rate exceeds 100%. Then, the voltage limiting unit 11 limits the magnitude of the driving voltage vector (vd *, vq *) based on the excess amount, so that the modulation rate command value does not exceed 100%. (Vd *, vq *) is corrected.

  As described above, the voltage limiting unit 11 and the modulation factor monitoring unit 16 constitute voltage limiting means for correcting the driving voltage vector (vd *, vq *) so that the applied voltage is equal to or lower than the detected value Vdc of the power supply voltage.

Further, the control device 1 has a function of the magnetic pole position estimation unit 24 that estimates the magnetic pole position.
The magnetic pole position estimation unit 24 includes an estimation voltage vector calculation unit 28 that calculates an estimation voltage vector (vhα *, vhβ *), an estimation current vector calculation unit 29 that calculates an estimation current vector (ihα, ihβ), and an estimation. Outer product calculation unit 30 for calculating outer product V × I of voltage vector (vhα *, vhβ *) for estimation and current vector for estimation (ihα, ihβ), and an estimated value θ of the magnetic pole position is calculated based on outer product V × I. It is comprised by the function of the estimated value calculation part 31 grade | etc.,.

  Here, the estimation voltage vectors (vhα *, vhβ *) are expressed as vectors by converting the command value of the estimation voltage into αβ axis components vhα *, vhβ * of the stationary coordinate system. In addition, the estimation current vectors (ihα, ihβ) are portions of the detected current vectors (iα, iβ) that are generated by adding the estimation voltage vectors (vhα *, vhβ *), and αβ axis components ihα, ihβ. Is expressed as a vector.

  That is, the magnetic pole position estimation unit 24 includes magnetic pole position estimation means for estimating the magnetic pole position based on the outer product V × I of the estimation voltage vector (vhα *, vhβ *) and the estimation current vector (ihα *, ihβ *). Eggplant.

  The estimation voltage vector calculation unit 28 calculates a command value for the estimation voltage so that the estimation voltage has a high frequency, and uses the command value for the estimation voltage as the αβ axis components vhα * and vhβ * of the stationary coordinate system. To be estimated voltage vectors (vhα *, vhβ *).

Further, the estimation voltage vector calculation unit 28 calculates the estimation voltage vector (vhα *, vhβ *) so as to be parallel to the estimated magnetic pole position (that is, the direction of the estimated value θ). In this case, when the αβ-axis components vhα * and vhβ * of the estimation voltage vectors (vhα * and vhβ *) are converted into the dq-axis components vhd * and vhq * of the rotating coordinate system, the q-axis component vhq * becomes zero. Therefore, the values of the αβ-axis components vhα * and vhβ * are obtained by the following formula 9 using the estimated value θ of the magnetic pole position and the command value of the estimation voltage (corresponding to the d-axis component vhd *).
[Formula 9]

  Note that the estimation voltage vector calculation unit 28 according to the first embodiment performs estimation so that the estimation voltage command value vhd * changes only by the same absolute value in positive and negative directions in a predetermined fluctuation cycle (for example, one control cycle). The voltage vector (vhα *, vhβ *) is determined.

  The estimation current vector calculation unit 29 performs driving voltage vectors (vα *, vβ *) within the detected current vectors (iα, iβ) in the fluctuation cycle (for example, one control cycle) of the estimation voltage command value vhd *. ) (That is, the driving current vector) is assumed not to fluctuate. Then, the estimation current vector calculation unit 29 calculates a difference vector between the detected current vector (iα, iβ) calculated in the current control process and the detected current vector (iα, iβ) calculated in the previous control process. This difference vector is calculated as an estimation current vector (ihα, ihβ).

The outer product calculation unit 30 uses the estimation voltage vector (vhα *, vhβ *) and the estimation current vector (ihα, ihβ) to calculate the outer product V × I using Equation 10 below.
[Formula 10]

  The estimated value calculation unit 31 calculates the estimated value θ of the magnetic pole position so that the outer product V × I substantially matches zero. That is, the estimated value calculation unit 31 performs PI calculation on the difference between the outer product V × I and zero (that is, the outer product V × I) using the proportional gain Kp and the integral gain Ki, thereby obtaining the estimated value θ. calculate. Note that the proportional gain Kp and the integral gain Ki are varied according to the estimated value ω of the magnetic pole rotation calculated by differentiating the estimated value θ.

  Further, the estimated value calculation unit 31 corrects the estimated value θ with a value obtained by integrating the estimated value ω of the magnetic pole rotation number. Furthermore, the estimated value calculation unit 31 estimates the magnetic pole position when the corrected estimated value θ is different from the sign of the energization amount command value i * and the sign of the rate of change of the estimated value ω of the magnetic pole rotation speed. The value θ is corrected by changing it by π.

  Here, since the estimation voltage is applied in the direction of the estimation value θ, when the estimation value θ is deviated from the true magnetic pole position, the estimation voltage vectors (vhα *, vhβ *) are also derived from the true magnetic pole position. Shift. As a result, a phase difference θvi occurs between the estimation voltage vector (vhα *, vhβ *) and the estimation current vector (ihα, ihβ), and an outer product V × I is generated.

  And about this outer product VxI, the following is known from the description using said [Formula 1]-[Formula 8]. That is, it is known that the sign of the outer product V × I has an inverse correlation with the sign of the voltage phase θv, and if the outer product V × I substantially matches zero, the voltage phase θv substantially matches zero. Since the voltage phase θv corresponds to the amount of deviation in the direction in which the estimation voltage is applied to the true magnetic pole position, if the calculation of the estimated value θ is repeated so that the outer product V × I substantially matches zero by PI calculation. The estimated value θ can be made to substantially coincide with the true magnetic pole position.

  The estimated value θ calculated by the estimated value calculating unit 31 is used when the coordinate converting unit 15 converts the αβ axis components iα and iβ into the dq axis components id and iq, and the coordinate converting unit 19 , Dq axis components vd *, vq * are used to convert αβ axis components vα *, vβ *. The estimated value θ is also used when the estimation voltage vector calculation unit 28 calculates the αβ-axis components vhα * and vhβ *.

  With the control block flow as described above, the control device 1 estimates the magnetic pole position at a predetermined time after the synchronous motor 2 is started. Thus, the control device 1 substantially matches the estimated value θ of the magnetic pole position with the true magnetic pole position in a predetermined time after the synchronous motor 2 is started.

  Thereafter, the control device 1 performs NS determination of the magnetic pole. That is, the control device 1 gives an applied voltage so as to reach magnetic saturation in both the positive and negative directions of the estimated magnetic pole position. And the control apparatus 1 performs NS discrimination | determination of a magnetic pole according to the energization amount when magnetic saturation is reached in the positive direction and the energization amount when magnetic saturation is reached in the negative direction.

[Effect of Example 1]
The magnetic pole position estimation unit 24 according to the first embodiment estimates the magnetic pole position based on the outer product V × I of the estimation voltage vector (vhα *, vhβ *) and the estimation current vector (ihα, ihβ).
Here, the sign of the voltage phase θv (the amount of deviation in the direction in which the estimation voltage is applied with respect to the true magnetic pole position) is determined from the sign of the outer product V × I according to the explanation using the above [Expression 1] to [Expression 8]. Can be estimated. The outer product V × I can be calculated by simple four arithmetic operations using the αβ-axis components vhα *, vhβ *, ihα, ihβ. Therefore, the magnetic pole position can be estimated using the outer product V × I that can be calculated by simple four arithmetic operations. For this reason, since the frequency which uses a trigonometric function, an inverse trigonometric function, etc. can be reduced when estimating a magnetic pole position, the processing load of the control apparatus 1 can be reduced.

The estimation voltage vector calculation unit 28 calculates the estimation voltage vectors (vhα *, vhβ *) so as to be parallel to the estimated magnetic pole position.
As a result, even if the estimation voltage vector (vhα *, vhβ *) is added to the driving voltage vector (vα *, vβ *), output torque corresponding to the estimation voltage vector (vhα *, vhβ *) is generated. do not do. For this reason, even if the estimation voltage as a disturbance is applied in addition to the driving voltage, an output torque corresponding only to the driving voltage, that is, an output torque corresponding to the operating condition of the synchronous motor 2 can be obtained.

In addition, the magnetic pole position estimation unit 24 estimates the magnetic pole position so that the outer product V × I substantially matches zero.
Thereby, when performing the convergence calculation by PI calculation, the influence of the winding resistance R of the armature coil, the linkage flux φa of the magnet, the d-axis inductance Ld, and the q-axis inductance Lq can be eliminated. For this reason, when the convergence calculation is performed, the influence of the use conditions of the synchronous motor 2 such as temperature can be excluded.

The magnetic pole position estimation unit 24 varies the proportional gain Kp and the integral gain Ki in accordance with the estimated value ω of the magnetic pole rotation calculated by differentiating the estimated value θ.
Thereby, the proportional gain Kp and the integral gain Ki can be varied so that the outer product V × I substantially coincides with zero earlier. For this reason, the estimated value θ of the magnetic pole position can be substantially matched with the true magnetic pole position earlier.

The magnetic pole position estimating unit 24 changes the estimated value θ of the magnetic pole position by π when the sign of the energization amount command value i * is different from the sign of the rate of change of the estimated value ω of the magnetic pole rotation speed. Correct it.
As a result, when the direction in which the control device 1 wants to rotate the magnetic pole is opposite to the direction in which the magnetic pole tries to rotate in response to a command from the control device 1, the estimated NS of the magnetic pole can be reversed. . For this reason, the rotation stop and reverse rotation of the synchronous motor 2 can be prevented.

Further, the voltage limiting unit 11 and the modulation rate monitoring unit 16 correct the driving voltage vector (vd *, vq *) so that the applied voltage is equal to or lower than the detected value Vdc of the power supply voltage.
As a result, the estimation voltage can be reliably applied, so that the magnetic pole position can be reliably estimated. For this reason, the reliability of the control apparatus 1 can be improved.

Further, the controller 1 estimates the magnetic pole position at a predetermined time after the start of the synchronous motor 2, and then applies an applied voltage so as to reach magnetic saturation in both the positive and negative directions of the estimated magnetic pole position. The magnetic pole is discriminated according to the energization amount when the magnetic saturation is reached in the direction and the energization amount when the magnetic saturation is reached in the negative direction.
As a result, it is possible to estimate the magnetic pole position and perform NS determination within a very short time after the start of the synchronous motor 2. Therefore, sensorless control can be performed very early after the synchronous motor 2 is started.

  The control apparatus 1 of Example 2 is demonstrated using FIG. In addition, the part which has the same function as Example 1 uses the same code | symbol, and abbreviate | omits description.

  According to the control device 1 of the second embodiment, the outer product calculation unit 30 calculates the outer product V × I using the estimation voltage vector (vhd *, 0) and the estimation current vector (ihd, ihq). . Here, the estimation voltage vector (vhd *, 0) is obtained by converting the command value of the estimation voltage into a dq axis component vhd *, 0 and expressing it as a vector. Further, the estimation current vector (ihd, ihq) is obtained by adding a portion generated by addition of the estimation voltage vector (vhd *, 0) in the detected current vector (id, iq) as a vector by the dq axis components ihd, ihq. It is a representation.

Note that the q-axis component of the estimation voltage vector (vhd *, 0) is zero because the estimation voltage is applied in parallel with the estimated magnetic pole position.
Further, the calculation method of the estimation current vector (ihd, ihq) is the same as the calculation method of the estimation current vector (ihα, ihβ) of the first embodiment.

  In addition, the disturbance injection unit 17 according to the second embodiment adds the estimation voltage vector (vhd *, 0) to the driving voltage vector (vd *, vq *) to obtain the dq axis components vd * + vhd *, vq *. A command voltage vector (vd * + vhd *, vq *) is obtained. Then, in the coordinate conversion unit 19, the command voltage vector (vd * + vhd *, vq *) is converted into a command voltage vector (vα * + vhα *, vβ) composed of αβ axis components vα * + vhα *, vβ * + vhβ * of the stationary coordinate system. * + Vhβ *).

  Further, the estimation voltage vector calculation unit 28 according to the second embodiment determines a fluctuation period of a portion based on the estimation voltage vector (vhd *, 0) in the applied voltage based on a random number. That is, the estimation voltage vector calculation unit 28 varies the fluctuation period of the command value vhd * for the estimation voltage based on the input from the random number generation unit 32. The random number generator 32 is a function for generating random numbers. Thereby, since the frequency of the voltage for estimation can be disperse | distributed, the noise accompanying application of the voltage for drive can be reduced.

  A control device 1 according to the third embodiment will be described with reference to FIG. In addition, the part which has the same function as Example 1 uses the same code | symbol, and abbreviate | omits description.

  According to the control device 1 of the third embodiment, the estimated value calculation unit 31 calculates the estimated value ω of the magnetic pole rotation number so that the outer product V × I substantially matches zero. That is, the estimated value calculation unit 31 calculates the estimated value ω by performing PI calculation on the outer product V × I using the proportional gain Kp and the integral gain Ki. Then, the estimated value calculation unit 31 integrates the estimated value ω to calculate the estimated value θ of the magnetic pole position. Further, the proportional gain Kp and the integral gain Ki are varied according to the estimated value ω of the magnetic pole rotation number calculated by the PI calculation.

  A control device 1 according to the fourth embodiment will be described with reference to FIG. In addition, the part which has the same function as Example 1 uses the same code | symbol, and abbreviate | omits description.

  The control device 1 according to the fourth embodiment sets a target value for the magnitude of the detected energization amount (that is, the magnitude of the detected current vector (id, iq)), and the magnitude of the energization amount is greater than the target value. Is also provided with a function of a reactive current increasing unit 34 (reactive current increasing means) that increases the command value id * of the d-axis current so that the magnitude of the energization amount substantially matches the target value.

  When the energization amount to the synchronous motor 2 is small, for example, Ia shown in FIG. 5, the difference (inductance difference) between the q-axis inductance Lq and the d-axis inductance Ld is small. It becomes difficult and error increases. Therefore, the target value Ib is set for the energization amount in consideration of the allowable range of error. When the energization amount is smaller than the target value Ib, the energization amount is increased to the target value Ib to increase the inductance difference. At this time, by increasing only the command value id * of the d-axis current, the amount of energization can be increased without affecting the output torque.

1 is a configuration diagram illustrating a control block flow of a control device (Example 1). FIG. (Example 2) which is a block diagram which shows the control block flow of a control apparatus. FIG. 9 is a configuration diagram illustrating a control block flow of a control device (third embodiment). (Example 4) which is a block diagram which shows the control block flow of a control apparatus. (Example 4) which is a correlation diagram of the magnitude | size of energization amount and dq axis | shaft inductance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Synchronous motor 11 Voltage limiting part (voltage limiting means)
14 Coordinate converter (detected current vector calculation means)
15 Coordinate converter (detected current vector calculation means)
16 Modulation rate monitoring unit (voltage limiting means)
24 Magnetic pole position estimation unit (magnetic pole position estimation means)
34 Reactive current increasing part (Reactive current increasing means)
(Iα, iβ) Detected current vector (id, iq) Detected current vector (vα *, vβ *) Drive voltage vector (vd *, vq *) Drive voltage vector iu Energization amount detection value iv Energization amount detection value (Vhα *, vhβ *) Estimation voltage vector (vhd *, 0) Estimation voltage vector (vα * + vhα *, vβ * + vhβ *) Command voltage vector (vd * + vhd *, vq *) Command voltage vector Vdc Power supply voltage Detection value (power supply voltage)
V x I outer product Kp proportional gain (parameter)
Ki integral gain (parameter)
θ Estimated value of magnetic pole position ω Estimated value of magnetic pole rotation speed Ld d-axis inductance Lq q-axis inductance θvi phase difference θv voltage phase (phase of applied voltage)
i * command value Ib energization amount target value V · I inner product (iα * + ihα *, iβ * + ihβ *) command current vector (id * + ihd *, iq * + ihq *) command current vector

Claims (12)

A control device for a synchronous motor having saliency,
Control of the synchronous motor that controls the voltage applied to the synchronous motor based on the command voltage vector by adding the voltage vector for estimation for estimating the magnetic pole position to the voltage vector for driving the synchronous motor. In the device
Detection current vector calculation means for calculating a detection current vector corresponding to the detection value based on the detection value of the energization amount to the synchronous motor;
An estimation current vector calculation means for calculating a portion generated by addition of the estimation voltage vector in the detection current vector as an estimation current vector;
Magnetic pole position estimating means for estimating the magnetic pole position based on the outer product of the estimation voltage vector and the estimation current vector ;
The estimation voltage vector is calculated so that it is parallel to the estimated magnetic pole position and the vector direction repeats reversal,
The control apparatus for a synchronous motor, wherein the magnetic pole position estimation means estimates the magnetic pole position so that an outer product of the estimation voltage vector and the estimation current vector substantially matches zero . A control device for a synchronous motor having saliency,
Control of the synchronous motor that controls the voltage applied to the synchronous motor based on the command voltage vector by adding the voltage vector for estimation for estimating the magnetic pole position to the voltage vector for driving the synchronous motor. In the device
Detection current vector calculation means for calculating a detection current vector corresponding to the detection value based on the detection value of the energization amount to the synchronous motor;
An estimation current vector calculation means for calculating a portion generated by addition of the estimation voltage vector in the detection current vector as an estimation current vector;
Magnetic pole position estimating means for estimating the magnetic pole position based on the outer product of the estimation voltage vector and the estimation current vector;
The estimation voltage vector is calculated so that it is parallel to the estimated magnetic pole position and the vector direction repeats reversal,
The magnetic pole position estimating means estimates the magnetic pole rotation speed so that the outer product of the estimation voltage vector and the estimation current vector substantially matches zero, and uses the estimated value of the magnetic pole rotation speed to determine the magnetic pole position. A control apparatus for a synchronous motor characterized by estimating . In the synchronous motor control device according to claim 1 or 2 ,
Cross product between the estimated current vector and the estimated voltage vector, and characterized in that is calculated using the estimated current vector and the estimated voltage vector consisting of components of the stationary coordinate system consisting of components of the stationary coordinate system Control device for synchronous motor. In the synchronous motor control device according to claim 1 or 2 ,
An outer product of the estimation voltage vector and the estimation current vector is calculated using an estimation voltage vector composed of components of a rotating coordinate system and an estimation current vector composed of components of a rotating coordinate system. Control device for synchronous motor. In the synchronous motor control device according to claim 1 ,
The magnetic pole position estimating means varies a parameter used when estimating the magnetic pole position in accordance with an estimated value of the magnetic pole rotation number calculated using the estimated value of the magnetic pole position . Control device. In the synchronous motor control device according to claim 2 ,
The control apparatus for a synchronous motor, wherein the magnetic pole position estimating means varies a parameter used when estimating the magnetic pole rotation speed in accordance with an estimated value of the magnetic pole rotation speed . In the synchronous motor control device according to claim 1 or 2 ,
The magnetic pole position estimating means corrects the estimated value of the magnetic pole position by changing by π when the positive / negative of the command value of the energization amount is different from the positive / negative of the rate of change of the estimated value of the magnetic pole rotation number. A control device for a synchronous motor. In the synchronous motor control device according to claim 1 or 2 ,
A control apparatus for a synchronous motor , comprising voltage limiting means for correcting the driving voltage vector so that the applied voltage is equal to or lower than a power supply voltage . In the synchronous motor control device according to claim 1 or 2 ,
The control apparatus for a synchronous motor, wherein the magnetic pole position estimation means determines a fluctuation period of a portion based on the estimation voltage vector in the applied voltage based on a random number . In the control method using the synchronous motor control device according to claim 1 or 2 ,
Estimating the magnetic pole position at a predetermined time after activation of the synchronous motor,
Apply applied voltage to reach magnetic saturation in both positive and negative direction of the estimated magnetic pole position,
A control method characterized by discriminating a magnetic pole according to an energization amount when magnetic saturation is reached in the positive direction and an energization amount when magnetic saturation is reached in the negative direction . In the synchronous motor control device according to claim 1 or 2 ,
A target value is set for the magnitude of the energization amount, and when the magnitude of the energization amount is smaller than the target value, the d-axis is set so that the magnitude of the energization amount substantially matches the target value. A synchronous motor control device comprising reactive current increasing means for increasing a current command value . Oite the control equipment of a synchronous motor according to claim 1 or claim 2,
The synchronous motor control apparatus, wherein the synchronous motor is a vehicle motor mounted on a vehicle .

Images