JP2016100949A - Torque ripple suppressing apparatus and torque ripple suppression method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately suppress torque ripples of a motor.SOLUTION: A signal calculation section 38 of a d-axis adjustment section 34 calculates an amplitude aof a cosine component and an amplitude bof a sine component of the Fourier series from a d-axis current signal iregarding a harmonic component of any order of the d-axis current signal i. A model learning section 40 generates a model signal Mfor removing ripple components from the d-axis current signal iby using a learning algorithm. A signal calculation section 42 of a q-axis adjustment section 36 calculates an amplitude aof a cosine component and an amplitude bof a sine component of the Fourier series from an angular acceleration signal φ. A model learning section 44 generates a model signal Mcorresponding to ripple components of the angular acceleration signal φof a q-axis current signal i. A d-axis current command value Iis superposed by the model signal Mand output. A q-axis current command value Iis superposed by the model signal Mand output.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a torque ripple suppressing device and a torque ripple suppressing method for suppressing torque ripple and the like generated in an electric motor or the like.

  In recent years, weight reduction of electric vehicles and industrial electric devices using an electric motor or the like as a drive source has been progressing in order to reduce environmental load. These weight-reduced devices are driven by an electric motor (motor) having an excellent weight torque ratio.

  On the other hand, in a synchronous motor, a linear synchronous motor, etc., torque ripple occurs in rotational torque and thrust torque during driving. Torque ripple generated in the motor causes noise, vibration, and the like in the entire drive device on which the motor is mounted. In particular, in a device that has been reduced in weight, vibration and noise of the device due to torque ripple of the motor become a problem.

  There is a mechanical method to take mechanical measures to suppress the mechanical resonance of the drive device on which the motor is mounted, but this mechanical method increases the size and weight of the device compared to the lighter device. As well as increase the cost of the device.

  On the other hand, the torque ripple of the motor can be reduced by devising an excitation method using an inverter used for driving the motor. From here, various control which suppresses the torque ripple which generate | occur | produces in a motor is proposed.

  For example, in Patent Document 1, pulsation of an electric motor is extracted by Fourier transform for an arbitrary order component, and learning control is performed so that a Fourier coefficient becomes 0 by PI control, and a pulsation compensation signal obtained by this learning control is expressed as d It is added to the shaft current command value and the q-axis current command value. In Patent Document 1, an electric motor is driven using a d-axis current command value and a q-axis current command value obtained by adding a pulsation compensation signal to at least one, and learning control for generating a pulsation compensation signal is converged. Torque ripple is suppressed.

  However, even if at least one of the d-axis current command value and the q-axis current command value is compensated by using a pulsation compensation signal obtained by learning control so that the Fourier coefficient becomes 0, the learning control does not converge. There is. For this reason, in Patent Document 1, when the learning control diverges and the pulsation of the electric motor cannot be suppressed, the polarity of the control gain is changed in a direction in which the learning control stably converges. When such a method is used, every time the learning control diverges, the control gain and the like are switched, so that it takes a long time to suppress the torque ripple.

JP 2010-57218 A

  An object of the present invention is to provide a torque ripple suppression device and a torque ripple suppression method that can accurately suppress torque ripple generated in an electric motor without causing divergence in learning control.

  In order to achieve the above object, a torque ripple suppressing device of the present invention includes a d-axis command value set such that each of a d-axis current and a q-axis current obtained from a detected drive current becomes an operation command value, and A torque ripple suppression device for a driving device driven by an electric motor based on each q-axis command value, wherein the d-axis current obtained by detecting the driving current is caused by torque ripple of the electric motor. First generation means for generating a d-axis compensation signal for removing a ripple component included in the d-axis current by learning control, and a first superposition for superimposing the d-axis command value and the d-axis compensation signal Means for detecting a parameter that changes due to driving of the electric motor and torque ripple of the electric motor, and a ripple component included in the parameter due to the torque ripple It includes a second generating unit configured to generate the learning control q-axis compensation signals for suppressing using a current, and a second superimposing means for superimposing said q-axis compensation signal and the q-axis command value.

  In addition, the torque ripple suppression method of the present invention provides a d-axis command value and a q-axis command value set so that each of the d-axis current and the q-axis current obtained from the detected drive current becomes an operation command value. Based on each, in the drive device for driving the electric motor, the ripple component included in the d-axis current due to the torque ripple of the electric motor is obtained from the d-axis current obtained by detecting the drive current. A d-axis compensation signal for removal is generated by learning control, the d-axis command value and the d-axis compensation signal are superimposed, and a parameter that varies depending on the driving of the motor and the torque ripple of the motor is detected by the detecting means. A q-axis compensation signal for suppressing a ripple component included in the parameter due to the torque ripple using the q-axis current is generated by learning control; Said q-axis compensation signal and by overlapping a command value to suppress the torque ripple of the electric motor.

  The torque ripple of the electric motor according to the present invention is an inherent torque ripple generated according to the driving of the electric motor, and appears in various parameters according to the driving of the electric motor. At this time, the drive current of the motor appears in association with both the d-axis current and the q-axis current.

  Here, in the present invention, the d-axis compensation signal is superimposed on the d-axis command value for driving the motor, thereby using the d-axis compensation signal and the ripple caused by the torque ripple of the motor included in the d-axis current. The component is removed from the d-axis current. Thereby, the ripple component resulting from the torque ripple of an electric motor is collected by q-axis current. Further, in the present invention, a parameter that changes according to the drive of the motor and the torque ripple of the motor is detected, and a q-axis compensation signal for removing the ripple component included in the detected parameter using the q-axis current is generated. . In the present invention, the torque ripple of the motor is suppressed by superimposing the q-axis compensation signal on the q-axis command value for driving the motor.

  In the present invention, known learning control using a Fourier series can be applied to the generation of the d-axis compensation signal and the q-axis compensation signal. At this time, the d-axis compensation signal excludes the ripple component included in the d-axis current, and the q-axis compensation signal excludes the torque ripple of the motor included in the parameter using the q-axis current. . Therefore, neither the d-axis compensation signal nor the q-axis compensation signal diverges in learning control.

  Further, the torque ripple suppressing device of the present invention includes the first generating unit, the first superimposing unit, the second generating unit, and the second superimposing unit, which are selected. To output each of the d-axis command value and the q-axis command value obtained by the first superimposing means and the second superimposing means, and when not selected, the d-axis compensation signal and the q-axis command value The first suppression unit and the second suppression unit that stop generating the compensation signal and hold the d-axis compensation signal and the q-axis compensation signal immediately before the stop, and the driving direction of the motor are determined and determined. Selecting means for selecting one of the first suppressing means and the second suppressing means and deselecting the other according to the driving direction.

  Some electric motors are driven such that the driving direction is switched. When the driving direction is switched, the ripple component due to the torque ripple of the motor included in the parameter changes. Corresponding to the driving direction of the motor, the first and second suppression means are provided, and the first or second suppression means is selected according to the driving direction of the motor, thereby suppressing the torque ripple of the motor. Can be held.

  In the present invention, each of the ripple component of the d-axis current and the ripple component of the parameter caused by the torque ripple can be a periodic function component with respect to the electrical angle of the motor. In the present invention, an electric angle or a rotation angle of the electric motor can be used as the parameter.

  The ripple component resulting from the torque ripple of the electric motor can be expressed as a periodic function component with respect to the electric angle of the electric motor to be driven. By making the ripple component a periodic function component of the electrical angle, even if a change occurs in the drive speed of the electric motor, the torque ripple can be accurately suppressed regardless of this change.

  According to the present invention, when the torque ripple of the motor is suppressed while learning control is performed, there is an effect that the torque ripple of the motor can be reliably suppressed without causing divergence in the learning control.

It is a schematic block diagram which shows the torque ripple suppression apparatus which concerns on 1st Embodiment. It is a schematic block diagram which shows the drive control apparatus which concerns on 1st Embodiment. It is a schematic block diagram which shows the drive control apparatus which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 shows a schematic configuration of a torque ripple suppressing device 10 according to the first embodiment. FIG. 2 shows a schematic configuration of the drive control device 12 including the torque ripple suppression device 10 according to the first embodiment.

  The drive control device 12 controls driving of a synchronous motor such as a three-phase synchronous motor, for example. In the first embodiment, a case will be described in which a three-phase synchronous motor (hereinafter referred to as a motor 14) is used as an example of a synchronous motor, and the drive control device 12 controls the driving of the motor 14. The torque ripple suppression device 10 suppresses torque ripple generated in the motor 14 driven by the drive control device 12.

The drive control device 12 includes a controller 16 and an inverter 18. As the controller 16, for example, a microcomputer is used and functions as the vector control unit 22 and the conversion unit 24. An operation command value such as a speed command value or a torque command value for the motor 14 is input from the operation command unit 26 to the controller 16. For example, when the torque command value is input, the vector control unit 22 sets and outputs the d-axis current command value I _d and the q-axis current command value I _q according to the torque command value.

The converter 24 converts the d-axis current command value I _d into a d-axis voltage command value V _d and converts the q-axis current command value I _q into a q-axis voltage command value V _q . In the vector control, for example, Clark conversion that converts a three-phase current into a two-phase current and park conversion that converts the two-phase current into a rotating coordinate system using a d-axis and a q-axis are performed. The conversion unit 24 performs reverse conversion of park conversion and reverse conversion of Clark conversion on the d-axis voltage command value V _d and the q-axis voltage command value V _q , so that each of U, V, and W of the motor 14 can be obtained. The phase voltage command values V _u , V _v , and V _w are converted and output to the inverter 18.

The inverter 18 generates and outputs voltages v _u , v _v , and v _w of the U, V, and W phases of the motor 14 based on the input voltage command values V _u , V _v , and V _w . The rotation shaft of the motor 14 is rotationally driven by the three-phase voltages v _u , v _v and v _w supplied from the inverter 18. A load 20 is connected to the rotating shaft of the motor 14, and the load 20 is operated by transmitting the rotation of the rotating shaft to the load 20.

Here, the drive control device 12 is provided with a current sensor 28 that detects the currents i _u , i _v , and i _w of the U, V, and W phases of the motor 14, and the vector control unit 22 includes a current sensor. Currents i _u , i _v , i _w detected by 28 are input. Further, the motor 14 is provided with a rotation angle sensor 30 for detecting the rotation angle θ of the motor 14, and the vector control unit 22 has a signal (hereinafter referred to as a rotation angle φ detected by the rotation angle sensor 30). , The rotation angle signal φ). Although the rotation angle sensor 30 may directly detect the rotation angle of the motor 14, for example, a rotary encoder is used, the vector control unit 22 counts the number of pulses output from the rotary encoder, and the count value is used as a rotation angle signal. It may be converted to φ.

The vector control unit 22 is provided with a converter 32. The converter 32 converts the currents i _u , i _v and i _w input from the current sensor 28 into a d-axis current (hereinafter referred to as a d-axis current signal) i _d and a q-axis current (hereinafter referred to as q) in the rotating coordinate system. Converted to i _q ). That is, the converter 32 performs Clark conversion and Park conversion to obtain the d-axis current signal _id and q-axis current signal _iq of the rotating coordinate system from the three-phase currents i _u , i _v , i _w .

In the present embodiment, the d-axis current command value and the q-axis current command value are applied as examples of the d-axis command value and the q-axis command value. The vector control unit 22 determines the d-axis current command values I _d and q so that the d-axis current signal i _d and the q-axis current signal i _q become values according to the operation command value (for example, torque command value). Feedback control for setting the shaft current command value _Iq is performed. Further, the vector control unit 22 synchronizes the d-axis current command value I _d and the q-axis current command value I _q with the electrical angle θ obtained from the rotation angle φ detected by the rotation angle sensor 30.

Thereby, the controller 16 controls the drive of the motor 14 so that the output torque according to a torque command value is obtained. A known configuration can be applied to the basic configuration of the controller 16 that performs such vector control, and detailed description thereof is omitted in the present embodiment. In the first embodiment, the rotation angle sensor 30 is used as an example, but an electrical angle detection sensor that detects the electrical angle θ instead of the rotation angle φ may be used. Further, without using a rotational angle sensor 30 and the electric angle sensors, the d-axis current signal i _d and the q-axis current signal i _q, it may be configured to estimate the rotation angle φ or electrical angle theta.

  By the way, in a synchronous motor including the motor 14, a unique torque ripple caused by the structure is generated. Torque ripple is caused by, for example, distortion of magnetic flux generated due to a structure such as unevenness of the iron core of the coil. Torque ripple generated in the motor 14 causes vibration and noise in the motor 14.

  In the first embodiment, the torque ripple suppression device 10 is provided in the controller 16, and the inherent torque ripple generated due to the structure of the motor 14 is suppressed by the torque ripple suppression device 10.

In the d-axis current signal id and the q-axis current signal iq, a ripple component corresponding to the torque ripple appears due to the torque ripple generated in the motor 14. Torque ripple suppressor 10 removes the ripple component due to torque ripple from the d-axis current signal i _d. Further, parameters such as a rotation angle that changes in accordance with the driving of the motor 14 are affected by torque ripple generated in the motor. The torque ripple suppression device 10 suppresses the torque ripple of the motor 14 by suppressing, using a q-axis current, a ripple component generated by being affected by the torque ripple for a preset parameter.

In general, when the number of pole pairs of the synchronous motor is n, the d-axis flux linkage is Φ (θ), the d-axis inductance is L _d (θ), and the q-axis inductance is L _q (θ), the torque ripple τ of the synchronous motor is , (1). The electrical angle is θ.

That is, the d-axis interlinkage magnetic flux Φ (θ), the d-axis inductance L _d (θ), and the q-axis inductance Lq (θ) are all periodic functions related to the electrical angle θ, and the torque ripple τ is the period of these cycles. It is the sum of functions.

Here, the torque ripple τ, the d-axis flux linkage Φ (θ), the d-axis inductance L _d (θ), and the q-axis inductance L _q (θ) can be expressed as the sum of a DC component and a periodic function component. it can. For each of the torque ripple τ, the d-axis flux linkage Φ (θ), the d-axis inductance L _d (θ), and the q-axis inductance L _q (θ), the direct current component is expressed as τ ₀ , Φ ₀ , L _d0 , and (1) is expressed by (2), where L _q0 of the periodic function component is Δτ, ΔΦ, ΔL _d , and ΔL _q .

  The periodic function component of each of these elements includes a harmonic component having an amplitude smaller than that of the fundamental wave. For each element, if the term greater than or equal to the square is sufficiently small and can be ignored, Equation (2) is 3) It can be simplified as an equation.

Τ ₀ which is the first term on the left side of the equation (3) is a DC component, and a substantial torque ripple is represented by a periodic function component Δτ. In order to suppress the torque ripple of the synchronous motor, the torque ripple periodic function component Δτ may be set to 0 (Δτ = 0), and when the torque ripple periodic function component Δτ = 0, equation (4) is obtained. . To suppress periodic function components Δτ of the torque ripple, (4) periodic function components .DELTA.i _d, and q-axis current of the d-axis current (d-axis current signal i _d) which satisfy the formula (q-axis current signal i _q) It is sufficient that the periodic function component Δi _q of.

(4) In the equation, the right side is the torque ripple component due to the magnetic flux distribution of the synchronous electric machine, the left side is the torque ripple component caused by the d-axis current i _d and the q-axis current i _q.

periodic function components .DELTA.i _d contained in the d-axis current signal i _d is a ripple component, in the present embodiment, as a periodic function components .DELTA.i d _{= 0} included in the d-axis current i _d, d-axis The current _id is controlled. In (4), when the periodic function components .DELTA.i _d of d-axis current _{i d 0 (Δi d = 0} ), (5) is obtained.

Therefore, in the equation (5), the periodic function component Δi _q of the q-axis current signal i _q that cancels the torque ripple on the right side is uniquely determined.

  As a technique for suppressing torque ripple using a Fourier series, there is a technique based on time, but when time is used as a reference, for example, when the rotational speed of an electric motor changes, the integration range is set according to the rotational speed. It is necessary to reset the time. On the other hand, in the present embodiment, by using the electrical angle θ as a reference, torque ripple can be suppressed regardless of changes in the rotational speed or the like. Further, in the electric motor, since the q-axis current has a greater influence on the torque ripple than the d-axis current, the torque ripple suppression efficiency can be improved by using the q-axis current.

Torque ripple suppressor 10 according to the present embodiment, by suppressing a periodic function components .DELTA.i _d contained in the d-axis current signal i _d, the torque ripple of the motor 14, a periodic function components of the q-axis current signal i _q .DELTA.i It is made to be included in _q . Further, the torque ripple suppression device 10 suppresses the torque ripple of the motor 14 by correcting the q-axis current command value I _q according to the torque ripple generated in the motor 14.

As shown in FIG. 2, the torque ripple suppression device 10 is provided between the vector control unit 22 and the conversion unit 24 of the controller 16. Torque ripple suppressor 10 is provided with a q-axis adjustment portion 36 corresponding to the d-axis adjustment portion 34, and the q-axis current command value I _q corresponding to the d-axis current command value I _d outputted from the vector control unit 22. In the torque ripple suppression device 10, the electric angle θ of the motor 14 is input from the vector control unit 22 to each of the d-axis adjustment unit 34 and the q-axis adjustment unit 36, and the d-axis adjustment unit 34 and the q-axis adjustment unit 36. Each operates in synchronization with the electrical angle θ. In the present embodiment, the d-axis adjustment unit 34 functions as a first generation unit, and the q-axis adjustment unit 36 functions as a second generation unit.

As shown in FIG. 1, the d-axis adjustment unit 34 includes a signal calculation unit 38 and a model learning unit 40, and the q-axis adjustment unit 36 includes a signal calculation unit 42 and a model learning unit 44. The torque ripple suppressor 10, as an example of the superimposing means, outputs the q-axis current command value i of the adder 46, and the model learning unit 44 for superimposing the output of the model learning unit 40 in the d-axis current command value i _d An adder 48 for superimposing on _q is provided. In the present embodiment, the adder 46 functions as an example of a first superimposing unit, and the adder 48 functions as an example of a second superimposing unit.

The d-axis adjustment unit 34 performs Fourier series integration to generate a model signal M _d as an example of a d-axis compensation signal for removing a periodic function component that is a ripple component from the d-axis current, and an adder 46 Output to. The adder 46 removes a periodic function component (ripple component) from the d-axis current by adding the model signal M _d to the d-axis current command value I _d input from the vector control unit 22. That is, the adder 46 adds the model signal M _d to the d-axis current command value I _d so as to be superimposed, and outputs a d-axis current command value I _d ^* that removes a ripple component from the d-axis current.

The q-axis adjusting unit 36 generates a model signal M _q as an example of a q-axis compensation signal for removing torque ripple generated in the motor 14 and outputs the model signal M _q to the adder 48. The adder 48 adds the model signal M _q to the q-axis current command value I _q input from the vector control unit 22 to output a q-axis current command value I _q ^* for suppressing torque ripple. That is, the torque ripple of the motor 14 is caused by inherent magnetic flux unevenness in the motor 14, and the magnetic flux unevenness affects a parameter that is changed by driving the motor 14. The q-axis adjusting unit 36 generates a model signal Mq corresponding to the magnetic flux unevenness causing the torque ripple. The adder 48, by adding the model signal M _q on the q-axis current command value I _q, and outputs the inhibit q-axis current command value I _q ^* and the magnetic flux non-uniformity causing a torque ripple.

In the first embodiment, the current sensor 28 and the converter 32 provided in the drive control device 12 function as detection means for the d-axis current (d-axis current signal i _q ). As shown in FIG. 1, in the d-axis adjustment unit 34, the d-axis current signal i _d obtained by converting the currents i _u , i _v , i _w detected by the current sensor 28 into the converter 32. Is entered. In the first embodiment, the rotation angle of the motor 14 is applied as a parameter including torque ripple information. As shown in FIG. 1, the q-axis adjusting unit 36 is provided with a differentiator 50. In the first embodiment, the rotation angle sensor 30 and the differentiator 50 function as parameter detection means. To do.

As shown in FIG. 2, the vector control unit 22 outputs the rotation angle of the motor 14 detected by the rotation angle sensor 30 (referred to as a rotation angle signal φ) to the q-axis adjustment unit 36. As shown in FIG. 1, in the q-axis adjusting unit 36, the rotation angle signal φ is input to the differentiator 50. Differentiator 50 is second order differential to the time the rotational angle signal phi inputted, generates an angular acceleration signal phi _a from the rotational angle signal phi. The angular velocity signal .phi.a, includes a ripple component caused by the torque ripple, the signal calculation section 42, an angular acceleration signal phi _a of the rotation angle signal phi is inputted.

Here, first, in the d-axis adjusting unit 34 will be described removal of the ripple component is a periodic function component contained in the d-axis current signal i _d. signal computing unit 38 of the d-axis adjustment unit 34, a predetermined harmonic components of orders included in the d-axis current signal i _d by Fourier series integration, the amplitude of each of the cosine wave component and a sinusoidal component of the Fourier series a _dn and b _dn are calculated.

Any harmonic components of orders included in the d-axis current signal i _d f _{d (theta),} when the electrical angle of the motor 14, theta, amplitude a _dn of the cosine wave component is represented by formula (6), The amplitude b _dn of the sine wave component is expressed by equation (7).

The model learning unit 40 of the d-axis adjustment unit 34 gives a predetermined gain to the amplitudes a _dn and b _dn calculated by the signal calculation unit 38 by a predetermined learning algorithm, and integrates them with one cycle of the electrical angle θ. Then, a model signal M _d having a Fourier series is generated. It shows a model signal _{M d} (8) below. The gains G _da and G _db are set by a learning algorithm as described above.

The d-axis adjustment unit 34. using a model signal M _d generated from the d-axis current signal i _d, obtain d-axis current command value I _d ^* for removing ripple components from the d-axis current.

Next, suppression of torque ripple in the q-axis adjustment unit 36 will be described.
In general, the torque of a synchronous motor can be regarded as a product of inertia of a rotor to which a load is connected and angular acceleration of a rotation angle. In this case, the angular acceleration of the rotation angle includes a ripple component resulting from torque ripple as a periodic function component. Further, the angular acceleration addition of the rotation angle, that is, the angular acceleration signal φa of the rotation angle φ is obtained by second-order differentiation of the rotation angle signal φ.

The q-axis adjusting unit 36 acquires the rotation angle signal φ from the vector control unit 22, and second-derivatizes the acquired rotation angle signal φ with the differentiator 50, thereby obtaining the angular acceleration signal φ _a as torque ripple information. Is generated.

signal calculation unit 42 of the q-axis adjusting unit 36, a predetermined harmonic components of orders included in the angular acceleration signal phi _a by Fourier series integration, each of the cosine wave component and a sinusoidal component of the Fourier series amplitudes a _qn and _aqn are calculated.

Table Here, any harmonic components of the orders contained in the angular acceleration signal φ _a f τ _(θ), when the electrical angle of the motor 14, theta, amplitude a _qn of the cosine wave component is a (9) The amplitude b _qn of the sine wave component is expressed by equation (10).

The model learning unit 44 of the q-axis adjustment unit 36 _applies a predetermined gain to the amplitudes a _qn and b _qn calculated by the signal calculation unit 42 by a predetermined learning algorithm, and integrates with one cycle of the electrical angle θ. Thus, a model signal M _q that is a Fourier series is generated. The model signal M _q is shown in equation (11). The gains G _qa and G _qb are set by a learning algorithm as described above.

The q-axis adjusting unit 36 uses the model signal M _q generated from the angular acceleration signal φ _a including the torque ripple information of the motor 14 to suppress the torque ripple of the motor 14 to the q-axis current command value I _q . A q-axis current command value I _q ^{* on} which the current component (model signal M _q ) is superimposed is obtained.

The drive control device 12 drives the motor 14 using the d-axis current command value I _d ^* and the q-axis current command value I _q ^* adjusted by the torque ripple suppression device 10.

In the drive control device 12 including such a torque ripple suppression device 10, for example, a torque command value is designated as an operation command, so that the vector control unit 22 causes the d-axis current and the q-axis current according to the torque command value. To set the d-axis current command value I _d and the q-axis current command value I _q . Further, the drive control device 12 drives the motor 14 based on the set d-axis current command value I _d and q-axis current command value I _q . Thereby, the motor 14 drives the load 20 with the output torque according to the torque command value by being in a steady state.

On the other hand, the motor 14 generates torque ripple caused by the structure. When torque ripple is generated in the motor 14, vibration and noise are generated. Further, the d-axis current signal i _d and the q-axis current signal i _q generated from the currents i _u , i _v , and i _{w of} the motor 14 include a periodic function component as a ripple component according to the torque ripple.

Drive control unit 12 a torque ripple suppressor 10 provided in the, d-axis adjusting section 34, the current _i u of the motor 14 being _driven, based on the i v, obtained from _{i w} d-axis current signal _{i d} The ripple component included in the d-axis current is removed. That is, the torque ripple suppressor 10, by excluding the ripple component from the d-axis current signal i _d, aggregates ripple component corresponding to the torque ripple in the q-axis current i _q. In addition, the torque ripple suppression device 10 generates the model signal M _q using torque ripple information indicating the torque ripple generated in the motor 14. The torque ripple suppression device 10 superimposes a current component in accordance with the generated model signal M _q on the q-axis current, so that the q-axis current command value I _q ^* includes the ripple component that suppresses the torque ripple in the q-axis current ^. Is generated. The torque ripple suppression device 10 suppresses the torque ripple of the motor 14 by including a ripple component that suppresses the torque ripple in the q-axis current.

Here, in order to cancel the periodic function components Δτ is a ripple component of the torque ripple, satisfies the relationship shown in the equation (4), the periodic function components contained in the d-axis current signal i _d .DELTA.i _d, and q The periodic function component Δi _q included in the axial current element signal i _q needs to exist.

However, (4) periodic function components .DELTA.i _d and periodic function components .DELTA.i _q satisfies the equation can not be uniquely determined. Thus, for example, based on the learning algorithm using single torque ripple information indicating the torque ripple, an attempt to remove a periodic function components .DELTA.i _d and periodic function components .DELTA.i _q, may not learning algorithm converges and learning It may take a long time for the algorithm to converge.

In contrast, in the torque ripple suppressor 10, to remove the periodic function components .DELTA.i _d contained in the d-axis current signal i _d by the learning algorithm using the d-axis current signal i _d. As a result, it is possible to suppress torque ripple using the above-described equation (5). Since the periodic function component Δi _q included in the q-axis current signal i _q satisfying the equation (5) is uniquely determined, for example, an angular acceleration signal φ _a including torque ripple information is used as _a predetermined learning algorithm. Thus, the learning algorithm can be reliably converged.

Therefore, in a state where the torque ripple of the motor 14 is suppressed by the torque ripple suppression device 10, the d-axis current (d-axis current signal i _d ) does not include a ripple component, but the q-axis current (q The shaft current signal i _q ) includes a ripple component in which a periodic function component for suppressing torque ripple is superimposed on a ripple component due to torque ripple. Thereby, the torque ripple suppression apparatus 10 can suppress the intrinsic | native torque ripple which generate | occur | produces in the motor 14 reliably and in a shorter time than before.

  Moreover, since the torque ripple suppression device 10 can suppress the torque ripple of the motor 14 using the functional components provided in the drive control device 12, there is no need to add a functional component for suppressing the torque ripple. An increase in size of the drive control device 12 can be suppressed.

  In the present embodiment described above, the torque ripple generated in the motor is detected by the rotation angle sensor 30, so that the second-order differentiation is performed by the differentiator 50 using the rotation angle φ as a parameter. However, the torque ripple information (parameter including the ripple component) is not limited to this, and may be obtained by using an electrical angle detection unit such as an electrical angle sensor that detects the electrical angle θ of the motor 14, for example. The torque ripple information may be detected by using a torque detection means such as a torque sensor. A periodic function component that becomes a ripple component may be extracted from the torque signal detected by the torque detection means, and the learning algorithm may be executed using the extracted periodic function component.

Further, the present invention is not limited to this, and any method for detecting torque ripple can be applied to the acquisition of torque ripple information. For example, the electrical angle (electrical angle signal θ) is not limited to a configuration that is directly detected by an electrical angle sensor or the like, and can be obtained by estimation from the d-axis current signal _id and the q-axis current signal _iq. The angle signal θ may be used.

[Second Embodiment]
Next, a second embodiment will be described. In the second embodiment, the functional parts equivalent to those in the first embodiment are given the same reference numerals as those in the first embodiment, and detailed description thereof is omitted.

  FIG. 3 shows a schematic configuration of the drive control device 60 according to the second embodiment. In the second embodiment, a linear synchronous motor (hereinafter referred to as a linear motor 62) is applied as the synchronous motor, and the drive control device 60 controls the drive of the linear motor 62.

The drive control device 60 includes, for example, a controller 64 including a microcomputer and an inverter 18, and the linear motor 62 is driven by three-phase voltages v _u , v _v and v _w output from the inverter 18. The linear motor 62 generates thrust torque when driven, and the corresponding load 66 and the linear motor 62 move relative to each other. Note that the linear motor 62 applied to the second embodiment is configured to switch the direction of the generated thrust torque, and is thereby reciprocated with respect to the load 66.

The controller 64 is provided with a vector control unit 68 and a conversion unit 70. Further, the linear motor 62 includes a current sensor 28 that detects currents _{u u} , i _v , and i _w of U, V, and W phases, and a position detector 72 that detects the position of the linear motor 62 with respect to the load 66. Is provided.

The vector control unit 68 receives the currents i _u , i _v , i _{w of} each phase detected by the current sensor 28. The position detector 72 uses, for example, a linear encoder provided between the linear motor 62 and the load 66, and a pulse signal output in accordance with the movement of the linear motor 62 is input to the vector control unit 68. The The vector control unit 68 counts the number of pulses input from the position detector 72 and adds or subtracts the count value according to the moving direction of the linear motor 62 to thereby move the position (relative position) and movement of the linear motor 62. The direction and amount of movement are determined.

The vector control unit 68 receives the operation command values such as the operation speed and the thrust torque from the operation command unit 26, and based on the input operation command values, the d-axis current command value _Id and the q-axis current command value. Set _Iq . At this time, the vector control unit 68 converts the three-phase currents i _u , i _v , i _w into a d-axis current signal i _d and a q-axis current signal i _q . The vector control unit 68 also sets the d-axis current command value I _d and the q-axis current command value I _q so that the converted d-axis current signal i _d and q-axis current signal i _q become values according to the operation command value. Perform feedback control to set.

Converting unit 70, by d-axis current command value I _d and the q-axis current command value I _q is input, the d-axis current command value I _d and the q-axis current command value d-axis voltage command value corresponding to the I _q V _d and q-axis voltage command value V _q are converted. The conversion unit 70 converts the converted d-axis voltage command value V _d and q-axis voltage command value V _q into three-phase voltage command values V _u , V _v , and V _w and outputs the converted voltage to the inverter 18. The inverter 18 generates three-phase voltages v _u , v _v , and v _w according to the voltage command values V _u , V _v , and V _w for each phase and supplies them to the linear motor 62. Thereby, the linear motor 62 is driven according to the operation command value. A known configuration can be applied to the drive control of the linear motor 62 in the drive control device 60, and detailed description thereof is omitted in the second embodiment.

  The controller 64 of the drive control device 60 is provided with a torque ripple suppression device 74 according to the second embodiment. In the second embodiment, as an example of an electric motor, a linear motor 62 whose moving direction is switched between one direction and the opposite direction to one direction is used. The torque ripple suppression device 74 includes a first torque ripple suppression unit 76A that functions as a first suppression unit corresponding to one direction, and a second torque that functions as a second suppression unit corresponding to a direction opposite to the one direction. A ripple suppression unit 76B is provided. The first torque ripple suppression unit 76A and the second torque ripple suppression unit 76B have the same configuration. Further, the torque ripple suppression units 76A and 76B differ from the torque ripple suppression device 10 shown in FIG. 1 in that the differentiator 50 is not provided in the q-axis adjustment unit 36, and the basic functions except for this are the same. It is equivalent. In the following description, the first torque ripple suppression unit 76A and the second torque ripple suppression unit 76B are collectively referred to as the torque ripple suppression unit 76. Moreover, since the torque ripple suppression part 76 has a function equivalent to the above-mentioned torque ripple suppression apparatus 10, detailed description is abbreviate | omitted.

As shown in FIG. 3, in the torque ripple suppression device 74, the first torque ripple suppression unit 76 </ b> A and the second torque ripple suppression unit 76 </ b> B have a d-axis current command value I _d and a q-axis current command value I, respectively. _q , d-axis current signal i _d , and electrical angle θ are input.

  In addition, the torque ripple suppression device 74 is provided with a distributor 78 and a selector 80 that function as selection means in the second embodiment. Further, the torque ripple suppression device 74 is provided with differentiators 82A and 82B that function as detection means in the second embodiment. The position signal P is input from the vector control unit 68 to the differentiator 82A in the previous stage, and the differentiator 82A inputs the position signal P with respect to time to differentiate the speed signal Ps of the linear motor 62. Is generated. Further, the differentiator 82B at the subsequent stage receives the speed signal Ps from the differentiator 82A, and the differentiator 82B generates the acceleration signal Pa by time-differentiating the speed signal Ps to generate the torque ripple suppression unit 76 (76A). , 76B).

Torque ripple suppressing unit 76 is to generate a model signal M _d from the d-axis current signal i _d for the d-axis current command value I _d, it superimposes the generated model signal M _d on the d-axis current command value I _d, Output as d-axis current command value I _d ^* .

Further, in the linear motor 62, the torque ripple is included in the thrust torque due to the occurrence of the torque ripple. This torque ripple appears as a ripple component in the acceleration signal Pa. The torque ripple suppression unit 76 uses the acceleration signal Pa as torque ripple information, and generates a model signal M _q for the q-axis current command value I _q from the ripple component (periodic function component) of the acceleration signal Pa. Further, the torque ripple suppression unit 76 superimposes (adds) the generated model signal M _q on the q-axis current command value I _q and outputs it as the q-axis current command value I _q ^* .

  On the other hand, in the torque ripple suppression device 74, the speed signal Ps generated by the previous differentiator 82 </ b> A is input to the distributor 78 and the selector 80. The sign of the speed signal Ps output from the differentiator 82A changes according to the moving direction of the linear motor 62 (moving direction of the mover). The first torque ripple suppression unit 76A corresponds to the direction in which the speed signal Ps is non-negative (Ps ≧ 0), and the second torque ripple suppression unit 76B is the direction in which the speed signal Ps is negative (Ps <0). Corresponding to

Here, the electrical angle signal θ output from the vector control unit 68 is input to the first torque ripple suppressing unit 76A or the second torque ripple suppressing unit 76B via the distributor 78. At this time, when the speed signal Ps is non-negative, the distributor 78 outputs the electrical angle signal θ to the first torque ripple suppression unit 76A and sets the electrical angle θ = 0 to the second torque ripple suppression unit 76B. The electrical angle signal θ shown is output. Further, when the speed signal Ps is negative, the distributor 78 outputs the electrical angle signal θ to the second torque ripple suppression unit 76B, and indicates the electrical angle θ = 0 to the first torque ripple suppression unit 76A. An electrical angle signal θ is output. The first torque ripple suppression unit 76A and the second torque ripple suppression unit 76B perform integration processing using the electrical angle signal θ because the input electrical angle signal θ is 0 (θ = 0). Stop and hold the model signals M _d and M _q generated just before the stop.

Further, the d-axis current command value I _d ^* and the q-axis current command value I _d ^* of each of the first torque ripple suppression unit 76A and the second torque ripple suppression unit 76B are d-axis current command values I _d and q The shaft current command value I _q is output to the conversion unit 70 via the selector 80. Here, when the speed signal Ps input from the differentiator 82A is non-negative, the selector 80 receives the d-axis current command value I _d ^* and the q-axis current command value input from the first torque ripple suppression unit 76A. I _q ^* is output to the conversion unit 70. When the speed signal Ps is negative, the selector 80 sends the d-axis current command value I _d ^* and the q-axis current command value I _q ^* input from the second torque ripple suppression unit 76B to the conversion unit 70. Output.

  As described above, the drive control device 60 is provided with the torque ripple suppression device 74 (torque ripple suppression unit 76), thereby reliably suppressing the torque ripple generated in the linear motor 62 in a relatively short time. be able to.

  The torque ripple suppression device 74 is provided with a first torque ripple suppression unit 76 </ b> A and a second torque ripple suppression unit 76 </ b> B, each of which suppresses torque ripple generated in the linear motor 62, depending on the drive direction of the linear motor 62. One is going to work. At this time, in the torque ripple suppression device 74, the torque ripple suppression unit 76 whose operation has stopped holds the learning result. Thereby, even if the moving direction of the linear motor 62 switches, the torque ripple suppression apparatus 74 can continue the state which suppressed the torque ripple of the linear motor 62. FIG.

  That is, the ripple component of the torque ripple may vary depending on the moving direction of the linear motor 62. In this case, it is necessary to perform processing for suppressing torque ripple every time the moving direction of the linear motor 62 is switched.

On the other hand, the torque ripple suppression device 74 is provided with a torque ripple suppression unit 76 for each movement direction of the linear motor 62, and the torque ripple suppression unit 76 in which the movement direction of the linear motor 62 does not correspond to the model signal M. _d and M _q are held. Therefore, the torque ripple suppression device 74 can maintain the state in which the torque ripple is reliably suppressed even when the moving direction of the linear motor 62 is switched.

  Moreover, since the torque ripple suppression device 74 can suppress the torque ripple of the linear motor 62 using the functional components provided in the drive control device 60, there is no need to add a functional component for suppressing the torque ripple. Therefore, it is possible to suppress an increase in size of the drive control device 60.

  In the second embodiment, the linear motor 62 whose movement direction is switched for the reciprocating operation has been described as an example. However, the motor is not limited to the linear motor 62 and the rotation direction of the rotation shaft (for example, the motor 14) You may apply to. Thereby, even when the rotation direction of the rotating shaft is switched, a state in which the torque ripple is suppressed can be maintained.

  Further, the functions of the d-axis adjustment unit 34 and the q-axis adjustment unit 36 used in the torque ripple suppression devices 10 and 74 can be executed by a computer program. Therefore, for example, a microcomputer provided in the controller 16 may be caused to execute function programs corresponding to the d-axis adjustment unit 34, the q-axis adjustment unit 36, and the like.

In the present embodiment described above, as an example, a model signal generated as a d-axis compensation signal and a q-axis compensation signal on the d-axis current command value I _d and the q-axis current command value I _q based on a learning algorithm. _Md and model signal _Mq are superimposed. Further, the vector control according to the present embodiment converts the d-axis current command value I _d and the q-axis current command value I _q to d-axis voltage command value V _d and q-axis voltage command value V _q, furthermore, U , V, and W are converted into voltage command values V _u , V _v , and V _w for each phase. From here, the d-axis voltage command value Vd and the q-axis voltage command value Vq may be applied as the d-axis command value and the q-axis command value. In this case, a d-axis compensation signal corresponding to the d-axis voltage command value V _d and a q-axis compensation signal corresponding to the q-axis voltage command value V _q are generated, and the generated d-axis compensation signal and q-axis compensation are generated. The signal may be superimposed on the d-axis voltage command value _Vd and the q-axis voltage command value _Vq .

As an actual drive control device, for example, a d-axis current target value and a q-axis current target value corresponding to the operation command value are set, and the set d-axis current target value and q-axis current target value are There is a configuration in which feedback control is performed using the d-axis current signal _id and the q-axis current signal _iq . In this drive control device, by performing feedback control, a d-axis voltage (d-axis voltage command value V _d ) and a q-axis voltage at which the d-axis current and the q-axis current become the d-axis current target value and the q-axis current target value. (Q-axis voltage command value V _q ) is generated.

In this case, the d-axis compensation signal for removing the ripple component from the d-axis current and the d-axis compensation signal for suppressing the ripple component included in the parameter using the q-axis current are the d-axis voltage command value V _d. And may be superimposed on the q-axis voltage command value _Vq . Further, not limited to this, and superimposes the d-axis compensation signal in the q-axis current signal i _d to be used for feedback control may be superimposed on the q-axis current signal i _q using q-axis compensation signal to the feedback control. As a result, the d-axis voltage command value V _d on which the d-axis compensation signal is superimposed and the q-axis voltage command value V _q on which the q-axis compensation signal is superimposed are obtained.

That is, in the present invention, the d-axis command value and the q-axis command value on which the d-axis compensation signal and the q-axis compensation signal are superimposed may be the d-axis current command value _Id and the q-axis current command value _Iq. Also, the d-axis voltage command value V _d and the q-axis voltage command value V _q may be used. Further, the d-axis command value and the q-axis command value on which the d-axis compensation signal and the q-axis compensation signal are superimposed may be a d-axis current target value and a q-axis current target value. Furthermore, the d-axis command value and the q-axis command value on which the d-axis compensation signal and the q-axis compensation signal are superimposed are the d-axis current signal i _d , q used in the feedback control described above for obtaining the d-axis voltage command value Vd. a q-axis current signal i _q for obtaining the axial voltage command value Vq may.

10, 74 Torque ripple suppression device 12, 60 Drive control device 14 Motor 16, 64 Controller 18 Inverter 22, 68 Vector control unit 24, 70 Conversion unit 28 Current sensor 30 Rotation angle sensor 32 Converter 34 d-axis adjustment unit 36 q-axis Adjustment unit 38, 42 Signal calculation unit 40, 44 Model learning unit 46, 48 Adder 50, 82A, 82B Differentiator 62 Linear motor 72 Position detector 76 (76A, 76B) Torque ripple suppression unit 78 Distributor 80 Selector

Claims (7)

A drive device for driving the electric motor based on each of the d-axis command value and the q-axis command value set so that each of the d-axis current and the q-axis current obtained from the detected drive current becomes an operation command value Torque ripple suppression device
From the d-axis current obtained by detecting the drive current, a d-axis compensation signal for removing a ripple component included in the d-axis current due to torque ripple of the motor is generated by learning control. First generation means;
First superimposing means for superimposing the d-axis command value and the d-axis compensation signal;
Detecting means for detecting a parameter that varies depending on driving of the motor and torque ripple of the motor;
Second generating means for generating, by learning control, a q-axis compensation signal for suppressing a ripple component included in the parameter due to the torque ripple using the q-axis current;
Second superimposing means for superimposing the q-axis command value and the q-axis compensation signal;
Torque ripple suppression device including Each includes the first generating means, the first superimposing means, the second generating means, and the second superimposing means, and when selected, the first superimposing means and the second superimposing means 2 outputs each of the d-axis command value and the q-axis command value obtained by the superimposing means of 2. When not selected, the generation of the d-axis compensation signal and the q-axis compensation signal is stopped and immediately before the stop. First suppression means and second suppression means for holding the d-axis compensation signal and the q-axis compensation signal;
A selection unit that determines a driving direction of the electric motor, selects one of the first suppression unit or the second suppression unit according to the determined driving direction, and deselects the other;
The torque ripple suppressing device according to claim 1, comprising: Each of the ripple component of the d-axis current and the ripple component of the parameter resulting from the torque ripple is a periodic function component of the electric angle of the motor.
The torque ripple suppression device according to claim 1 or 2. The detecting means detects an electric angle or a rotation angle of the electric motor as the parameter;
The torque ripple suppression device according to any one of claims 1 to 3. A drive device for driving an electric motor based on each of a d-axis command value and a q-axis command value set so that each of a d-axis current and a q-axis current obtained from the detected drive current becomes an operation command value In
A d-axis compensation signal for removing a ripple component included in the d-axis current due to torque ripple of the motor is generated by learning control from the d-axis current obtained by detecting the drive current. And
Superimposing the d-axis command value and the d-axis compensation signal;
Detecting parameters that change due to the drive of the motor and torque ripple of the motor by means of detection,
A q-axis compensation signal for suppressing a ripple component included in the parameter due to the torque ripple using the q-axis current is generated by learning control,
Superimposing the q-axis command value and the q-axis compensation signal,
A torque ripple suppressing method for suppressing torque ripple of the electric motor. Each of the ripple component of the d-axis current and the ripple component of the parameter resulting from the torque ripple is a periodic function component of the electric angle of the motor.
The torque ripple suppressing method according to claim 5. As the parameter, an electric angle or a rotation angle of the electric motor is used.
The torque ripple suppression method according to claim 5 or 6.

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