JP5912495B2 - Electric motor control device - Google Patents

Description

The present invention relates to a control device for an electric motor.

Since torque pulsation of motors such as DC brushless motors causes vibration and noise, a control device that reduces torque pulsation by vector control using motor rotation angle information and torque amplitude / phase information has been developed. Yes. A typical example will be described with reference to FIGS. In the device of the present invention, the electric motor 34 has three-phase windings 51, 52, 53, and the AC driving device 4.
8 is a three-phase AC motor that is driven at 0, and the driving device 40 is a driving force command means 2 in FIG.
5 and driving means 45. In addition, the electric motor 34 is connected to the load device 35 and is installed on the attachment device 36 depending on the application. 7 and 8 are merely examples of the driving device 40 as the prior art, and do not limit the subject matter of the present invention. In FIG. 9, the rotation angle information of the electric motor is sequentially obtained by the rotation angle detection means 47 by the d / q axis current means 4.
1, current compensation means 42, current control means 43, three-phase → dq conversion means 46. The rotation angle detection means includes a case where a sensor such as an encoder is used, and an angle estimation control method without using the sensor.

In the drive device 40, the d-axis and q-axis current command values are obtained from the speed command value and the actual rotation speed, and are determined by the d / q-axis current command means 41. The obtained command value is corrected by the current compensation means 42 based on the rotation angle information obtained from the actual speed, and is connected to the current control means 43.
Three-phase alternating current is detected by the three-phase current detection means 48, 49, 50, and the detected three-phase alternating current is output from the three-phase → dq conversion means 46 as Id and Iq signals and connected to the current control means. The The driving means 45 gives current signals Iuf, Iwf, Ivf, which are driving signals, to the windings of the electric motor based on the voltage command values Vu, Vv, Vw of the orthogonal stationary coordinate system. Driving means 45
Therefore, an output current based on the voltage command value is supplied to the electric motor.

In recent years, electric motors driven by such a control system have been adopted as prime movers for various systems. For example, when the motor is a permanent magnet synchronous motor, torque pulsation is likely to occur due to its saliency, which causes vibration and noise. Here, the sixth harmonic is described as an example of torque pulsation as an example, but the present invention proposes the nth harmonic, and this proposal is not limited to n = 6, and there is one nth harmonic. Assuming m pieces above. The U-phase induced voltage of the synchronous motor is given by Equation 1. The induced voltages of the V phase and the W phase are also given by the same formulas whose phases are shifted by 120 degrees.

In Equation 1, θe is an electrical angle, ω is an electrical angular velocity, Ψ _f is a maximum value of armature linkage flux by a permanent magnet per phase, Ψ _c5 , Ψ _c7 , Ψ _s5 , and Ψ _s7 are electrical _machines by a permanent magnet. This is the maximum number of interlinkage magnetic fluxes of the fifth and seventh sine and cosine components per phase of the child winding. For Formula 1 for three phases d-
Equation 2 is obtained after q conversion.

In Equation 2, θe is a lead electrical angle from the d-axis U phase.

Equation 2 represents that the fifth and seventh harmonics included in the induced voltage of the three-phase model become the 6f component of the induced voltage of the dq axis model. Depending on the slot combination, if the harmonics contained in the induced voltage and the alternating current are other than 5 and 7, the integers m-1 order and m + 1 of the three-phase model
The next harmonic of the induced voltage becomes the mf component of the induced voltage of the dq axis model. Since the torque of a motor is obtained by the product of voltage and current, in the case of a motor in which harmonics of integer multiples are included in at least one of voltage and current, the torque has pulsation, and the motor rotates while pulsating. To do. When the torque of the motor is periodically changed, it is transmitted as vibration to the load side connected to the shaft of the motor in the case of low speed rotation, and in the case of high speed rotation, the sound wave radiated from the vibration reaches the audible range and becomes noise.

As an example, FIG. 10 shows a waveform of torque pulsation. The horizontal axis in FIG. 10 represents time, and the vertical time represents torque (for example, the unit is Nm). With the torque command value from the motor 40 such as an inverter as the center value, periodic torque pulsation shown in FIG. 10 occurs due to distortion of the induced voltage and current waveform, slot combination of the motor, and the like. In addition, since the electric motor is connected to the load and the mounting device, torque fluctuations and pulsations are also transmitted to the load and the mounting device, causing vibration.
In the case of an electric motor in which torque pulsation still remains high even when the motor rotational speed is increased, the radiated sound due to vibration of the mounting device etc. reaches the audible range, causing noise. When the frequency component of the periodic torque fluctuation matches the natural frequency of the electric motor or the mounting device, the vibration and noise further increase.

Therefore, in order to solve these problems, Patent Document 1 proposes a motor control device that realizes torque pulsation or vibration / noise reduction.

Here, the problem when the electric motor is further attached to the attachment device will be described. FIG. 8 is a block diagram of the entire apparatus. The rotational speed and torque of the electric motor 34 can be varied by the driving force command means 25. The electric motor 34, the load device 35, and the attachment device 36 shown in FIG. 8 each have a natural frequency.

A DC brushless motor, such as a permanent magnet synchronous motor, excites the natural frequency when the generated torque pulsating radial harmonic electromagnetic force reaches near the natural frequency of either the motor 34, the load device 35, or the mounting device 36. However, there is a problem that torque pulsation increases and rotational fluctuation increases, or vibration and noise of the apparatus increase. In addition, excitation of the resonance frequency of the electromagnetic force harmonics in the rotating direction causes the torque output from the motor 34 to become unstable.

To solve such a problem, a learning algorithm has been developed that suppresses torque pulsation by voltage control by detecting and learning torque pulsation generated in the electric motor. In this learning algorithm, for example, frequency information of torque pulsation generated due to the nth-order harmonic is collected by the amplitude and phase detection means, and the d-axis and q-axis corresponding to these are reduced so as to reduce the n-th order torque pulsation. Amplitude and phase information of integer multiple harmonics of current is learned in advance and held inside the algorithm, and re-learning is repeated even if the rotational speed changes, and voltage control is performed to cancel torque pulsations that are integral multiples of the rotational frequency. .

JP 2006-288076 A

However, the conventional torque pulsation learning algorithm is based on a steep phase and amplitude change near the resonance frequency when the frequency of the torque pulsation, which is an integral multiple of the motor speed, matches the resonance frequency of the motor, load device, or mounting device. The phase components of the d-axis and q-axis harmonic currents cannot be correctly learned and held inside the control device, and the d-axis and q-axis currents cannot be learned and torque pulsation or radial vibration and noise cannot be reduced. A problem occurs.

The problem to be solved by the present invention is to provide a motor control device that reduces vibrations and noise of the motor or motor peripheral devices.

An electric motor control device according to an embodiment includes an electric motor and a mechanical device, and an electric motor system of an electric motor system having a natural frequency. In the electric motor control device, an axial torque detection unit that detects an axial torque of the electric motor, and a frequency component of the axial torque , A notch filter that cuts a frequency band having a center frequency of (1 / n) times the natural frequency (where n is the harmonic order that matches the natural frequency), and a rotation angle that detects rotation angle information of the motor Based on the detection means, the operation frequency command means for outputting the operation frequency of the electric motor, the shaft torque from the notch filter, the rotation angle information from the rotation angle detection means, and the operation frequency from the operation frequency designation means, Torque amplitude phase calculating means for calculating the phase.

The control block diagram of the control apparatus of the electric motor which concerns on 1st Embodiment. Relationship between torque and Iq signal of motor and harmonics. The Iq signal and torque waveform of an electric motor on which torque pulsation control is performed. The control block diagram of the control apparatus of the electric motor which concerns on 2nd Embodiment. The block diagram of the control apparatus signal processing apparatus of the electric motor which concerns on 2nd Embodiment. Control block diagram of electric motor control apparatus according to third embodiment The figure which shows the torque of the control apparatus of the electric motor of 1st Embodiment thru | or 3rd Embodiment. Motor and equipment block diagram Block diagram of conventional AC motor and drive means The figure which shows the torque of the control apparatus of the conventional electric motor.

Embodiments according to the present invention will be described below. At least one embodiment relates to a compensation means for providing a current or voltage compensation value for reducing torque pulsation or vibration or noise of the motor or motor peripheral equipment to a control current or voltage command value in a motor control device.

(First embodiment)
(Constitution)
FIG. 1 is a configuration diagram illustrating an electric motor control apparatus according to the first embodiment. FIG. 1 shows a shaft torque detecting means 1 for detecting shaft torque from a driving means 45 for driving an electric motor, and a motor 34, a motor peripheral device (load device 35, mounting device 3) among frequency components of the detected shaft torque.
6) the notch filter 3 that cuts the 1 / n band of the resonance frequency, the rotation angle detection means 2 that detects the rotation angle information of the motor 34 that is operating at a variable rotation frequency, and the operation that is the drive command value. A torque amplitude / phase calculation means 4 for calculating the torque amplitude and phase by calculating the shaft torque signal processed by the frequency command means 9 and the notch filter 3 and the rotation angle information obtained by the rotation angle detection means 2; The amplitude gain multiplication means 5 for multiplying the amplitude information obtained by the torque amplitude / phase calculation means 4 with a gain, and the result of the amplitude gain multiplier 5 indicate nf corresponding to the shaft eccentricity in the mechanical phenomenon or the torque pulsation rotational force fluctuation. A value calculated by the nf voltage amplitude time integration means 6 that gives a voltage amplitude correction value that cancels the current harmonic component, the nf voltage amplitude time integration means 6, and the torque amplitude / phase calculation means 4. When in the vicinity of the natural frequency, thereby avoiding the Iq / Iq0 gain calculation means 7 to avoid sudden change of learning amplitude information of nf, the sudden change of the learning phase information nf Iq0
For the electrical angle calculated by the / Iq gain multiplying means 13 and the torque amplitude / phase calculating means 4, a gain is given to the harmonic component of n times corresponding to torque pulsation rotational force fluctuation or shaft eccentricity in the mechanical phenomenon. nf multiplication means 21, multiplication operation means 16 for multiplying the result of Iq0 / Iq gain multiplication means 10, phase gain multiplication means 12 for giving a phase gain to the output result of 16, and nf voltage phase time for giving a voltage phase correction value This is a control device 100 having an integrating means 13 and a sine calculating means 8.

(Action / Effect)
The control method by the control apparatus 100 of FIG. 1 is demonstrated below. The notch filter 3 of FIG.
The operation of this embodiment by the q / Iq0 gain multiplying means 7 and the Iq0 / Iq gain multiplying means 10 will be conceptually described based on FIG. 1, FIG. 2, FIG. 3, and FIG. Then, a detailed control method is demonstrated using numerical formula.

FIG. 2A shows the current frequency component of the motor 34 in which torque pulsation occurs. Electric motor 3
Since the torque of 4 is obtained by the product of current and voltage, for example, in the case of a permanent magnet synchronous motor having two poles, the double harmonic 2f is an axial eccentricity in the rotation phenomenon of the motor, and 6f is a torque pulsation. Here, 2f and 6f will be described as examples, but the scope of claims of the present invention covers objects other than 2 and 6. When the output torque of the rotating machine 34 includes torque pulsation, the actual time waveform obtained by the shaft torque detecting means 1 in FIG. 1 is a period relative to the torque command value as shown in the output waveform 58 shown in FIG. It has a characteristic pulsation and causes vibration and noise. The torque pulsation learning algorithm collects and learns torque amplitude and rotation angle information corresponding to 2f and 6f inside the control device,
Current or voltage control is performed to reduce 2f and 6f shown in FIG. By this control, the motor 34 rotates smoothly with little torque pulsation, so that the torque waveform shown in FIG. 9B can be obtained, and the motor 34 and the apparatus can be reduced in vibration and noise. However, if 2f or 6f matches the natural frequency 56 of any one of the electric motor 34, the load device 35, and the mounting device 36, 6f or 2f shown in FIG. 3C causes a sudden change in amplitude and phase, and learning is established. Torque pulsation increases. Therefore, in the present invention, the motor 34,
After grasping the natural frequency of the load device 35 and the device 36, the notch filter 3 having the characteristic of cutting the frequency band of 1/2 or 1/6 of that is inserted in the front stage of the torque amplitude / phase calculation means. Propose. Thus, in the example, when 2 or 6 times the fundamental frequency coincides with the natural frequency, the nf amplitude information is not input to the torque amplitude / phase calculation means 4, so that a sudden change in the amplitude near the resonance frequency is avoided. it can. 6f · 52 is Iq / Iq0 due to a sudden change in torque generated when the n-th harmonic, which is a torque pulsation component, comes close to the natural frequency.
Re-learning can be prevented by increasing the amplitude in advance by the Iq / Iq0 gain calculation means 7 that gives a gain to prevent double. Similarly, with respect to the phase component of torque pulsation, the Iq0 / Iq gain multiplying means 10 can cancel out a sudden fluctuation so that the gain in phase learning does not change. As a result, the amplitude and phase information of 2f or 6f that should be reduced is retained, so that the torque pulsation control algorithm operates even in the vicinity of the resonance frequency, and the torque pulsation can be reduced. Obtain stable torque.

  In the following, a method for realizing the above-described action is presented using mathematical formulas.

As a method for controlling torque pulsation, current command values are corrected for the d-axis and the q-axis as shown in Equation 3. I _dc is a d-axis current command value, I _qc is a q-axis current command value, I _dc0 is a d-axis current correction value,
I _qc0 is a q-axis current correction value.

In (Expression 4) and (Expression 5), the nth-order torque pulsation component is sine wave corrected on each of the d-axis and the q-axis. n
Is the order, a _d , a _q are the amplitude correction values of the d-axis and the q-axis, l is the harmonic component ratio, θe is the electrical angle, P _d
, P _q is the d axis and q axis phase correction values. For example, torque pulsation or vibration due to the m-th harmonic of the dq axis model is applied to the original signal represented by the sum of sine waves of amplitude a _i and phase φ _i.
For the purpose of noise reduction, learning is performed using the numerical integration value ph of the original signal and the sine function sin (−mθ + ζ) of the learning device as an evaluation function.

The d-axis current command value and the q-axis current command value supplied in this way are, for example, current control means 43.
From dq → three-phase conversion means 44, a three-phase alternating current is output from the drive means 45, and the motor 34 is rotated, and torque T with less rotational fluctuation is obtained with reduced torque pulsation. Equation 6
Represents the torque T.

In Equation 6, _{P n} is the number of pole _{pairs, Ψ a = √3 / 2Ψ f} = √3Ψ e, Ψ e is the effective value of the armature flux linkage ascribable to the permanent magnet, _{L d} is d-axis inductance, _{L q} is q-axis Inductance.

P _n , L _{d and} L _q are determined from the electrical design of the motor. When reduction of vibration due to torque pulsation or electromagnetic harmonics of the motor is performed by current control, the reduction performance is determined by how to compensate for ψa, I _d , and I _q . For the original signal represented by the sum of sine waves of amplitude ai and phase φi, for example, torque pulsation or vibration caused by m-th harmonic of the dq axis model
For the purpose of noise reduction, learning is performed using the numerical integration value ph of the original signal and the sine function sin (−mθ + ζ) of the learning device as an evaluation function. When numerical integration is performed, ph is expressed by a sine function whose phase is the phase of the mth harmonic + (ζ-π / 2) and whose amplitude is the amplitude of the mth harmonic or a value proportional thereto. . Therefore, determining ζ such that ph = 0 is equivalent to learning the phase component of the m-th harmonic that becomes a torque pulsation or vibration / noise source. Similarly, on the amplitude side, the sine function sin (−kθ + ζ−π / 2) of the original signal and the learning device side is provided.
Is required to converge to the torque ripple amplitude value ak to be canceled.

For example, in the prior art, there is an embodiment in which ad and Pd of the current compensation values for the d-axis and the q-axis are determined as in Expression 7.

In the case of the above equation, the correction values g _pd and dF _rf are added or individually added or subtracted according to the values of dI _dc and δdI _dc / δt. Current command correction signal dIdc is 0 phase P ^ol (the current command correction signal maximum or minimum) was last used and vibration or noise dFrf when the
^A new adjustment phase P ^new _d is determined by the sum of ^d _d . FIG. 3C shows a representative example in which the frequency component of periodic torque pulsation that should be reduced excites the natural frequency of the electric motor and the mechanical device.
The point where dI _dc = 0 or dI _{qc = 0} is the maximum change point of the torque waveform increased by resonance with the mechanical system. Also, in the vicinity of the natural frequency of the motor and the mechanical device, the phase of torque pulsation, whose phase is uniformly shifted from the fundamental wave by sensing, suddenly changes during sensing (the mechanical angle fluctuates + or -180 degrees). Since the sign of δdI _dc / δt is not determined before and after the passage of the natural frequency, the amplitude correction command value and the phase correction command value are not determined and fluctuate, or torque pulsation is excited and increased in the vicinity of the natural frequency. Therefore, there is a problem that the control for reducing the torque pulsation is not stable because the correct amplitude correction command value and the phase correction command value are calculated. Therefore, in order to prevent the harmonics of n times the advance angle θ _{e from} coincident with the natural frequency and suddenly changing the amplitude and phase, the advance angle θ _e
The notch filter 3 is provided that cuts the 1 / n band of the natural frequency of the machine of the motor 34, the load device 35, and the mounting device 36 in the detected frequency component of the shaft torque. As a result, even if the frequency of 6f matches the resonance frequency, for example, the control device held by the amplitude gain multiplication means and the phase gain multiplication means reduces without learning a sudden change in amplitude and phase inversion due to the coincidence. The learning is realized while maintaining the amplitude and phase information of the nf harmonic component. In addition, Iq is given to prevent gains of the nth harmonic and the nth order torque pulsation from being multiplied by Iq / Iq0 due to a sudden change in torque generated when the nth order harmonic as a torque pulsation component comes close to the natural frequency. By increasing the amplitude in advance by the / Iq0 gain calculation means 7, it becomes possible to prevent relearning. Similarly, with respect to the phase component of torque pulsation, the Iq0 / Iq gain multiplying means 10 can cancel out a sudden fluctuation so that the gain in phase learning does not change.

According to the configuration of the present embodiment as described above, even if the rotation state of the electric motor changes, the vibration and noise generated from the electric motor or the motor peripheral device are reduced by reducing the torque pulsation while avoiding resonance between the machine and the torque pulsation. It is possible to provide a motor control device capable of reducing the above.

Further, the control device that reduces one n-th order torque pulsation described in the present embodiment while avoiding excitation due to the natural frequency of the device and a sudden change in torque includes an nf voltage amplitude time integration unit 6 and an nf multiplication unit. 14, nf voltage phase time integration means 13 is applied to m number of n-order (n = 2, 3, 4,...) W harmonics, and m notch filters are respectively expanded. It is possible to apply to torque pulsation.

Still further, the control device that reduces the m-th order torque pulsations described above while avoiding excitation due to the natural frequency of the device and a sudden change in torque can reduce the target to radial electromagnetic harmonics that are vibration and noise sources. It is possible to expand. Specifically, the shaft torque detection means 1 may be replaced with vibration or noise detection means, or may be changed to detection means that estimates the angle and torque from the current obtained by the current detection means. In addition, for the d-axis current, Iq / Iq gain and Iq0 / Iq gain are installed on both sides of the d-axis and q-axis current, and the nth radial electromagnetic harmonic excites the natural frequency of the device. Prevents sudden changes in radial electromagnetic harmonics. The nf voltage amplitude time integration means 6 and n
The f multiplication means 14 and the nf voltage phase time integration means 13 are divided into m n-th orders (n = 2, 3, 4,...
w) Applying to harmonics and expanding m notch filters, respectively, can be applied to m radial electromagnetic harmonic reduction.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. In addition, about the thing which has the same structure as FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

(Constitution)
FIG. 4 is a configuration diagram showing an electric motor control apparatus according to the second embodiment of the present invention. FIG.
Is a notch filter 24 and a natural frequency automatic detecting means 23 for detecting the natural frequency of the electric motor 34, the load device 35 and the mounting device 36 using the frequency component of the torque obtained by the torque amplitude / phase calculating means 4, 2 shows a second control device 200 having a notch filter characteristic updating means 22 for changing the filter characteristic of the notch filter 24 based on the result of the natural frequency automatic detection means 23.

(Action / Effect)
The notch filter 24 of the present embodiment automatically searches for and assigns the frequency using the natural frequency automatic detecting means 23 and the notch filter characteristic updating means 22 of FIG. 5 before executing the torque pulsation control algorithm. It is possible. The natural frequency automatic detection means 23 will be described in detail. Using the driving force command means 25 and the driving means 45 in FIG. 5, for example, the frequency of a three-phase current is given as a sweep signal, and torque is detected by the torque detection means 28 from an electromagnetically excited motor. A pulsation component is extracted from the detected torque by the torque pulsation detecting means 29. The increased portion feature amount extraction means 30 performs Fourier transformation on the extracted maximum value of the torque pulsation component, and extracts the natural frequency obtained therefrom. Based on the extracted natural frequency, a filter characteristic that cuts a 1 / n band of the natural frequency is determined. At this time, the natural frequency for which the filter characteristic has been determined is the “existing” natural frequency, and the pre-learning data storage means 32.
Hold on. After that, a new natural frequency is detected by the torque pulsation increasing feature amount extraction means 30 in the natural frequency automatic detection means 23. The newly detected natural frequency is set as the “new” natural frequency. The “existing” natural frequency and the “new” natural frequency are compared by the comparison means 31. At this time, if the “existing” natural frequency and the “new” natural frequency are different values, the value of the “new” natural frequency is transferred to the natural frequency storage means 33. The natural frequency recording means 33 is connected to the notch filter characteristic updating means 22 of FIG. 4 and is used for changing the characteristics of the notch filter.

The search algorithm can be implemented not only for frequency sweeps, but also for signals having broadband frequency components such as M-sequences, step signals, impulse signals, and white noise signals.

In addition, the notch filter 24 is accompanied by a change in the Young's modulus of the motor material due to secular change, a corrosion of the frame, a change in the natural frequency of a motor peripheral device such as a motor and a load device due to dust,
The natural frequency automatic detection means 23 for detecting the natural frequency of the electric motor 34, the load device 35, and the mounting device 35 using the torque amplitude / phase calculation component of FIG. 5, and the notch filter 24 based on the result of the automatic resonance frequency detection step. Notch filter characteristic updating means 22 for changing the filter characteristic of
Thus, it is also possible to periodically detect the latest resonance frequency and internally correct the filter characteristics such as the cut-off frequency band of the notch filter 24.

According to the configuration of at least one of the embodiments described above, even if the rotation state of the motor changes, the torque pulsation is reduced while avoiding resonance between the machine and the torque pulsation, and is generated from the motor or the motor peripheral device. It becomes possible to provide an electric motor control device capable of reducing vibration and noise.

Further, even if the natural vibration value of the motor or the motor peripheral device changes due to an external or time factor, it is possible to cope with the change and reduce the vibration and noise generated from the motor or the motor peripheral device.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In addition, about the thing which has the same structure as FIG. 1 thru | or 5, the same code | symbol is attached | subjected and description is abbreviate | omitted.

(Constitution)
FIG. 6 is a configuration diagram showing an electric motor control apparatus according to the third embodiment of the present invention. Based on the result of the natural frequency automatic detecting means 23 for detecting the natural frequency of the motor and the mounting device using the frequency component of the torque obtained by the torque amplitude / phase calculating means 4, A control device 300 having an alarm output unit 70 for outputting an alarm when the current filter characteristic of the filter 3 and the notch filter characteristic updating unit 24 for comparing the result of 23 and the compared result value are different is shown.

(Function)
The notch filter 3 shown in FIG. 6 is formed by loosening the connection between the device and the motor, connection between the devices, change in Young's modulus of the motor device material over time, change in the natural frequency of the motor and its load device due to frame corrosion, dust, and the like. When the natural frequency band blocked by the notch filter 3 is passed, a warning can be issued from the alarm output 70.

According to the configuration of at least one of the embodiments described above, even if the rotation state of the motor changes, the torque pulsation is reduced while avoiding resonance between the machine and the torque pulsation, and is generated from the motor or the motor peripheral device. It becomes possible to provide an electric motor control device capable of reducing vibration and noise.

In this embodiment, the notch filter replacement time is detected and output to an external display or the like.
Since the notch filter can be replaced at an appropriate time, the reliability of the motor control device can be improved.

All the embodiments described above are presented by way of example and do not limit the scope of the invention. Therefore, the present invention can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope of the invention described in the claims and equivalents thereof.

For example, a motor control device that reduces torque pulsation or radial electromagnetic harmonics of a motor has a notch filter, but the type thereof is an IIR (infinite impulse response) filter, FIR.
Both (finite impulse response) filters can be used.

In addition, for example, a motor control device that reduces torque pulsation or radial electromagnetic harmonics of a motor has a notch filter, but a filter that automatically corresponds to the amplitude and phase of the natural frequency from current, torque, rotation angle information, etc. Adaptive filters that converge to the characteristics are available.

1 Axis torque detection means 2 Rotation angle detection means 3 Notch filter 4 Torque amplitude / phase calculation means 5 Amplitude gain means 6 nf voltage amplitude integration means 7 Iq / Iq0 gain calculation means 8 Sine calculation means 9 Driver fraction command means 10 Iq0 / Iq gain multiplication means 11 multiplication means 12 phase gain multiplication means 13 nf voltage phase integration means 14 nf multiplication means 15 adder 22 notch filter characteristic update means 23 natural frequency automatic detection means 24 adaptive notch filter 25 driving force command means 29 Torque pulsation detection means 30 Torque pulsation increase part feature quantity extraction means 31 Comparison means 32 Pre-learning data storage means 33 Natural frequency storage means 34 Electric motor 35 Load device 36 Mounting device 40 Drive device 41 d / q-axis current command means 42 Current compensation means 43 Current control means 44 dq → three-phase conversion means 45 drive means 4 3-phase → dq converter 47 the rotation angle detecting unit 48 three-phase current detecting means (1)
49 Three-phase current detection means (2)
50 Three-phase current detection means (3)
51 Three-phase winding (1)
52 Three-phase winding (2)
53 Three-phase winding (3)
54 Waveform including harmonics in frequency domain 55 Waveform including harmonics in which 6f in frequency domain excites natural frequency 56 Natural frequency 57 Output waveform of tachometer 58 Output waveform of tachometer during unstable operation 59 Operation 6th harmonic of frequency 60 Torque command value 61 Torque time waveform with torque pulsation 62 Torque time waveform with reduced torque pulsation 70 Alarm output means 100, 200, 300 Controller

Claims (6)

In a motor control device of an electric motor system having an electric motor and a mechanical device and having a natural frequency,
Shaft torque detecting means for detecting the shaft torque of the electric motor;
A notch filter that cuts a frequency band having a center frequency of (1 / n) times the natural frequency (n is the order of a harmonic that matches the natural frequency) in the frequency component of the shaft torque;
Rotation angle detection means for detecting rotation angle information of the electric motor;
Operating frequency command means for outputting the operating frequency of the electric motor;
Torque amplitude phase calculating means for calculating the amplitude and phase of torque based on the shaft torque from the notch filter, the rotation angle information from the rotation angle detecting means, and the operating frequency from the operating frequency command means;
An electric motor control device. Natural frequency automatic detection means for automatically detecting the natural frequency at a predetermined timing;
Notch filter characteristic updating means for updating the frequency cut by the notch filter based on the natural frequency detected by the natural frequency automatic detection means;
An electric motor control device according to claim 1. Torque pulsation detecting means for detecting pulsation from the torque detected by the torque detecting means;
Exciting torque pulsation detected by the torque pulsation detecting means, and detecting an increased torque pulsation, a torque pulsation increasing portion feature amount extracting means;
Pre-learning data storage means in which the natural frequency obtained from the increased portion feature quantity extraction means is held;
Comparison means for comparing the existing natural frequency already held by the pre-learning data storage means with the new natural frequency obtained by the increased feature quantity extraction means, and
If the new natural frequency is different from the existing natural frequency in the comparison means, natural frequency storage means for holding the new natural frequency as the natural frequency;
An electric motor control device according to claim 1. As a result of comparison by the comparison means, if the existing natural frequency and the new natural frequency are different, an alarm output means for outputting an alarm;
The motor control device according to claim 3. Amplitude time integration means for providing an amplitude correction value for time-integrating the nth harmonic component in the amplitude from the torque amplitude phase calculation means to reduce vibration due to the nth harmonic;
Phase time integration means for providing a phase correction value for time-integrating the nth harmonic component in the phase from the torque amplitude phase calculation means to reduce vibration due to the nth harmonic;
An electric motor control device according to claim 1.   The motor control apparatus according to any one of claims 1 to 5, wherein the notch filter is an infinite impulse response filter or a finite impulse response filter.

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