Control system and refrigeration cycle device

Abstract

A control system according to an embodiment of the present invention includes an electric motor, an inverter, a vibration detection device, and a control unit. The electric motor is built into a compressor. The inverter drives the electric motor. The vibration detection device is installed in piping connected to the compressor. The vibration detection device detects piping vibration generated in the piping and outputs a piping vibration detection signal. The control unit controls the inverter in order to suppress vibration of the piping on the basis of the piping vibration detection signal output from the vibration detection device.

Description

Control system and refrigeration cycle device

[0001] This application claims priority to Japanese Patent Application No. 2024-033350, filed on March 5, 2024, the contents of which are incorporated herein by reference.

[0002] It is known that load torque pulsation occurs during the compression process of a compressor in refrigeration cycle devices such as air conditioners. Load torque pulsation can cause vibration and noise in the compressor and the piping system connected to the compressor. A conventional technique for solving this problem involves reducing the speed pulsation of the electric motor built into the compressor to suppress compressor vibration. However, even when compressor vibration, which is the source of vibration, is suppressed, significant vibration occurs only in the piping system if the vibration frequency matches the mechanical resonance frequency of the piping system. This can have adverse effects on the piping system, such as accelerating metal fatigue in the piping.

[0003] In order to suppress compressor vibration, conventional technology estimates the pulsating torque that causes noise and vibration in the motor, and suppresses speed pulsation by adding a compensation current equivalent to the pulsating torque to the torque current command value.The pulsating torque can be calculated from the axial error and moment of inertia value, assuming that the axial error estimated from the induced voltage is generated by speed pulsation caused by the pulsating torque.

[0004] One conventional technique for suppressing compressor vibration is to learn the relationship between mechanical angle and load torque in advance. One such method is to attach an acceleration sensor near the compressor terminals, or to embed the acceleration sensor in the terminal cover. The acceleration value is then measured for each mechanical angle, and the load torque for the motor is calculated from the acceleration value. In this way, the relationship between mechanical angle and load torque is learned in advance. During actual operation, control is performed so that the load torque for each mechanical angle learned in advance matches the output torque, thereby suppressing speed pulsation.

[0005] However, while the above-mentioned conventional technology can suppress the speed pulsation of the motor built into the compressor, if the piping has a different resonance frequency from that of the compressor, there is a possibility that resonance will be excited and piping vibration will become apparent.

[0006] Furthermore, in the above-described conventional technology, the load torque is calculated based on the acceleration value of an acceleration sensor attached to the compressor terminals or terminal cover and learned in advance. Then, based on the results of this learning, the electric motor is controlled to output a torque that matches the load torque, thereby suppressing compressor vibration. In other words, even if vibration suppression control of the compressor body is performed using this type of prior learning, there is a possibility that piping vibration may not be sufficiently suppressed. To sufficiently suppress piping vibration based on prior learning, it was necessary to understand in advance the correlation between compressor vibration, the speed pulsation of the electric motor built into the compressor, and piping vibration.

[0007] Japanese Patent No. 6622452 Japanese Patent No. 4906819

[0008] The problem to be solved by the present invention is to provide a control system and a refrigeration cycle device that can not only suppress compressor vibration by reducing the speed pulsation of the electric motor built into the compressor, but also suppress vibration in the piping system caused by the vibration frequency matching the mechanical resonance frequency of the piping system, etc.

[0009] In one embodiment, the control system includes an electric motor, an inverter, a pipe, a vibration detection device, and a control unit. The electric motor is built into a compressor. The inverter drives the electric motor. The pipe is connected to the compressor. The vibration detection device is installed on the pipe. The vibration detection device detects pipe vibrations occurring in the pipe and outputs a pipe vibration detection signal. The control unit controls the inverter to suppress vibrations of the pipe based on the pipe vibration detection signal output from the vibration detection device. The pipe has a first pipe end connected to the compressor, a second pipe end located opposite the first pipe end in an extension direction of the pipe, one or more straight sections located between the first pipe end and the second pipe end, and one or more bent sections located between the first pipe end and the second pipe end. The bent section located closest to the first pipe end in the extension direction of the one or more bent sections has a connection section connected to the straight section located closest to the first pipe end in the extension direction of the one or more straight sections. The vibration detection device is installed at any one of the connecting portion, the bent portion located between the connecting portion and the second pipe end, and the straight portion located between the connecting portion and the second pipe end. The vibration detection device detects the pipe vibration at the location where the vibration detection device is installed in the pipe, and outputs a pipe vibration detection signal to the control unit.

[0010] 1 is a block diagram showing a schematic functional configuration of the entire control system of the first embodiment. FIG. 1 is a schematic diagram showing an example of an installation location of a vibration detection unit (vibration sensor) of the first embodiment. FIG. 2 is a graph showing the relationship between the rotation speed of the electric motor and a piping detection signal detected by the vibration detection unit in the first embodiment. FIG. 3 is a block diagram showing an example of the functional configuration of a vibration suppression control unit according to the first embodiment. FIG. 4 is a graph showing an example of a signal waveform when an input to a compensation amount generation unit is switched from a piping vibration signal to a velocity vibration signal, assuming that the signal amplification unit of the first embodiment is not present. FIG. 5 is a block diagram showing a schematic functional configuration of a signal amplification unit of the first embodiment. FIG. 6 is a graph showing an example of a signal waveform when an input to a compensation amount generation unit is switched from a piping vibration signal to a velocity vibration signal, assuming that the signal amplification unit of the first embodiment is not present. FIG. 7 is a block diagram showing a functional configuration of a vibration suppression control unit according to the first embodiment (variant). FIG. 8 is a block diagram showing the internal functional configuration of a signal amplification unit in the vibration suppression control unit ( FIG. 8 ) of the first embodiment (variant). FIG. 9 is a flowchart showing an example of a processing procedure for an amplification factor adjustment unit of the first embodiment (variant) to automatically adjust an amplification factor. 1 is a graph showing an example of a signal waveform when the input to the compensation amount generator is switched from a pipe vibration signal to a velocity vibration signal when the vibration suppression control unit of the first embodiment (variation) is used. FIG. 2 is a block diagram showing the internal functional configuration of a pipe vibration signal / velocity vibration signal switching unit of the first embodiment (including variation). FIG. 3 is a block diagram showing the schematic functional configuration of the internal compensation amount generator of the first embodiment. FIG. 4 is a block diagram showing the schematic functional configuration of a compensation amount generator of a variation of the first embodiment (having multiple tolerance values). FIG. 5 is a graph showing the relationship between the rotation speed of the motor and pipe detection signals detected by a vibration detection unit at each of multiple locations on the pipe for a second embodiment. FIG. 6 is a block diagram showing the schematic functional configuration of a vibration suppression control unit for switching between pipe vibration suppression control and velocity pulsation suppression control based on multiple vibration detection signals according to the second embodiment. FIG. 7 is a block diagram showing the schematic functional configuration of a vibration suppression index selection unit when multiple vibration detection signals are present according to the second embodiment. FIG. 8 is a block diagram showing the schematic functional configuration of a vibration suppression index selection unit of the second embodiment (variation). FIG. 9 is a block diagram showing an example functional configuration of a vibration suppression control unit of the third embodiment. FIG. 11 is a block diagram showing a schematic functional configuration of a piping vibration signal / velocity vibration signal switching unit in the third embodiment.Graph showing an example of the relationship between the values ​​of the weighting coefficients Wvib and Wwm in the third embodiment. Graph showing an example of the relationship between the speed command value, the weighting coefficient for control, the pipe vibration signal amplitude before and after amplification, the speed vibration signal amplitude before and after amplification, and the vibration signal amplitude A in the third embodiment. Block diagram showing a schematic functional configuration of a vibration suppression control unit for switching between pipe vibration suppression control and speed vibration suppression control based on a weighting function corresponding to the rotation speed, based on a plurality of pipe detection signals, in the third embodiment (variation). Block diagram showing a schematic internal functional configuration of a pipe vibration signal / speed vibration signal switching unit in the third embodiment (variation). Graph showing an example of changes in the weighting coefficients WvibP, WvibQ, and Wwm according to the rotation speed in the third embodiment (variation). Graph showing an example of the relationship between the speed command value, the weighting coefficient for control, the pipe vibration signal amplitude before and after amplification, the speed vibration signal amplitude before and after amplification, and the vibration signal amplitude A in the third embodiment (variation). Block diagram showing a schematic overall functional configuration of a control system of the fourth embodiment. Block diagram showing a schematic functional configuration of a vibration suppression control unit in the fourth embodiment. 10 is a block diagram showing a schematic functional configuration of a compensation amount generating unit in a fourth embodiment. 11 is a schematic diagram for explaining the operation of a refrigeration cycle device that can be a control target in each of the first to fourth embodiments. 12 is a block diagram showing an example of the internal configuration of a computer when at least some of the functions are realized using a computer in each of the first to fourth embodiments.

[0011] Hereinafter, a control system and a refrigeration cycle apparatus according to an embodiment will be described with reference to the drawings.

[0012] 1 is a block diagram showing a schematic functional configuration of an entire control system according to a first embodiment. The illustrated control system 101 controls an electric motor 12 for driving an air conditioning compressor. As shown in the figure, the control system 101 includes a speed command unit 1, a speed control system 2, a current command correction unit 3, a current control system 4, a dq / UVW coordinate converter 5, a modulation unit 6, an inverter 7 (INV), a UVW / dq coordinate converter 8, a speed estimation unit 9, an integrator 10, a pole logarithm multiplication unit 11, a vibration extraction unit 17, a vibration suppression index selection unit 18, a signal amplification unit 19, a pipe vibration signal / speed vibration signal switching unit 20, a compensation amount generation unit 21, and an air conditioner 13.

[0013] Of the components of the control system 101, the functions including the vibration extraction unit 17, the vibration suppression index selection unit 18, the signal amplification unit 19, the piping vibration signal / velocity vibration signal switching unit 20, and the compensation amount generation unit 21 may be collectively referred to as a vibration suppression control unit 16.

[0014] The air conditioner 13 includes an electric motor 12 therein. As described above, the electric motor 12 drives an air conditioning compressor. Electric power is supplied to the electric motor 12. The air conditioner 13 also includes piping. The piping carries fluid (such as air) input to the air conditioner 13 and fluid (such as air) output from the air conditioner 13. Among these piping, piping targeted for vibration suppression by the control system 101 is specifically referred to as vibration-suppression target piping 14. A vibration detection unit 15 (a sensor, also referred to as a "vibration detection device") is attached to a predetermined location on the vibration-suppression target piping 14. The vibration detection unit 15 detects vibrations in the piping and passes a signal of the vibration to the vibration extraction unit 17.

[0015] Of the components of the control system 101 described above, the components excluding the air conditioner 13, which is the object of control, may be called a “control device.” The control device performs control to suppress vibrations related to the air conditioner 13.

[0016] The speed command unit 1 commands the speed (angular velocity) of the electric motor 12 .

[0017] The speed control system 2 uses the speed command ωmRef given from the speed command unit 1 and the speed estimated value ωm^ output from the speed estimation unit 9 to generate the d-axis current command IdRef0 and the q-axis current command IqRef0 based on the following equations (1) and (2).

[0018] IdRef0=0...(1)

[0019] IqRef0=(Kpasr+Kiasr / s)×(ωmRef-ωm^)...(2)

[0020] In the equation (2), Kpasr is a speed control proportional gain, Kiasr is a speed control integral gain, and s is a complex number.

[0021] Equations (1) and (2) represent a method for determining a current command value in the case of a control method in which the d-axis current command value is fixed to 0. Maximum torque / current control, flux-weakening control, or the like may be applied instead of equations (1) and (2).

[0022] The current command correction unit 3 uses the q-axis current command IqRef0 generated by the speed control system 2 and the vibration suppression compensation current command Iqcmp output from the vibration suppression control unit 16 to generate new d-axis current command IdRef and q-axis current command IqRef based on the following equations (3) and (4).

[0023] IdRef=IdRef0...(3)

[0024] IqRef=IqRef0+Iqcmp...(4)

[0025] The current control system 4 calculates a d-axis voltage command value Vd and a q-axis voltage command value Vq using the d-axis current command IdRef and the q-axis current command IqRef acquired from the current command correction unit 3, and the currents Id and Iq. The currents Id and Iq are obtained by converting at least two-phase currents (e.g., Iu and Iw) of the three-phase currents flowing through the motor 12 into a dq coordinate system in a UVW / dq coordinate converter 8.

[0026] The current control system 4 calculates the d-axis voltage command value Vd and the q-axis voltage command value Vq based on the following equations (5) and (6), respectively.

[0027] Vd=(Kpd+Kid / s)×(IdRef-Id)...(5)

[0028] Vq=(Kpq+Kiq / s)×(IqRef-Iq)...(6)

[0029] In equations (5) and (6), Kpd is the d-axis current control proportional gain, Kid is the d-axis current control integral gain, Kpq is the q-axis current control proportional gain, and Kiq is the q-axis current control integral gain.

[0030] The dq / UVW coordinate converter 5 converts the d-axis voltage command value Vd and the q-axis voltage command value Vq into three-phase AC voltage commands VuRef, VvRef, and VwRef in accordance with the electrical angle θ using the following equations (7), (8), and (9).

[0031] VuRef=√(2 / 3)×Va×cos(θ+φ)...(7)

[0032] VvRef=√(2 / 3)×Va×cos(θ+φ−2π / 3) (8)

[0033] VwRef=√(2 / 3)×Va×cos(θ+φ+2π / 3)...(9)

[0034] In the formulas (7), (8), and (9), Va and φ respectively represent the amplitude and phase of the voltage command. The amplitude Va and phase φ can be calculated by the following formulas (10) and (11), respectively.

[0035] Va=√(Vd^2+Vq^2) ...(10)

[0036] φ=tan-1(Vq / Vd)...(11)

[0037] The modulator 6 generates a gate signal by comparing the magnitude of the three-phase AC voltage commands VuRef, VvRef, and VwRef with a carrier wave such as a triangular wave.

[0038] Upon receiving the gate signal, the inverter 7 outputs three-phase AC voltages Vu, Vv, and Vw and applies them to the electric motor 12 .

[0039] The UVW / dq coordinate converter 8 converts the sensor detection values ​​of two of the three-phase currents flowing through the electric motor 12, for example, Iu and Iw, into the dq coordinate system based on the electrical angle θ. However, the UVW / dq coordinate converter 8 uses an estimated electrical angle θ^ as the electrical angle θ. That is, the estimated speed value ωm^ estimated by the speed estimator 9 is integrated by an integrator 10, and the output estimated mechanical angle θm^ is multiplied by the number of pole pairs by a pole pair number multiplier 11 to obtain the estimated electrical angle θ^.

[0040] The speed estimator 9 calculates an estimated speed value ωm^ using the d-axis current Id and q-axis current Iq output by the UVW / dq coordinate converter 8 and the d-axis voltage command value Vd generated by the current control system 4. The speed estimation method used by the speed estimator 9 is not particularly limited. The speed estimator 9 may estimate the speed using a method that uses the q-axis voltage command value Vq.

[0041] The integrator 10 integrates the input value and outputs a signal representing the integration result, which is then passed to the pole logarithm multiplication unit 11.

[0042] The pole pair number multiplication unit 11 multiplies the input value by the number of pole pairs of the motor, and passes the multiplication result to the dq / UVW coordinate converter 5 and the UVW / dq coordinate converter 8.

[0043] The vibration suppression control unit 16 performs control to suppress vibration. As a feature of this embodiment, the vibration suppression control unit 16 has both a piping vibration suppression function and a speed vibration suppression function. The vibration suppression control unit 16 has an internal configuration described below. This allows smooth switching between the piping vibration suppression function and the speed vibration suppression function, for example, depending on the rotation speed of the electric motor. The piping vibration suppression function of the vibration suppression control unit 16 is a function to suppress vibration of the piping due to resonance with the natural frequency of the piping, etc. The speed vibration suppression function is a function to suppress vibration due to an increase in the rotation speed of the electric motor.

[0044] The rotation speed of the motor is the number of rotations per unit time or the rotation angle per unit time. In this embodiment, the rotation speed may be simply referred to as "speed."

[0045] As shown in the figure, the vibration suppression control unit 16 is configured to include five functions: a vibration extraction unit 17, a vibration suppression index selection unit 18, a signal amplification unit 19, a piping vibration signal / velocity vibration signal switching unit 20, and a compensation amount generation unit 21.

[0046] The vibration extraction unit 17 extracts vibrations based on a signal output from a vibration detection unit 15 (sensor) provided on the pipe.

[0047] The vibration suppression index selection unit 18 selects and outputs a vibration suppression index from the pipe vibration detection signals detected by each of the multiple vibration detection units 15. Note that when only one pipe vibration detection signal is input to the vibration suppression index selection unit 18, no special selection process is performed and the input pipe vibration detection signal is output as is. Note that the pipe vibration detection signal includes an amplitude and a phase. In other words, the vibration suppression index selection unit 18 outputs the amplitude and phase of the selected pipe vibration detection signal.

[0048] The signal amplifier 19 appropriately amplifies the input signal and outputs it. The signal amplifier 19 amplifies the signal at an appropriate amplification factor. This makes it possible to prevent or mitigate switching shock caused by a sudden change in signal value when switching control (switching between piping vibration suppression control and velocity vibration suppression control).

[0049] The pipe vibration signal / speed vibration signal switching unit 20 switches between pipe vibration suppression control and speed vibration suppression control at a predetermined switching speed based on the rotation speed of the electric motor.

[0050] The compensation amount generating unit 21 receives the signals (vibration signal amplitude A and vibration signal phase) passed from the pipe vibration signal / velocity vibration signal switching unit 20 as input, and generates and outputs a compensation amount for vibration suppression.

[0051] The vibration extraction unit 17, vibration suppression index selection unit 18, signal amplification unit 19, piping vibration signal / velocity vibration signal switching unit 20, and compensation amount generation unit 21 that constitute the vibration suppression control unit 16 will be described in more detail later with reference to another figure.

[0052] The air conditioner 13 is a device for adjusting the temperature of air by using a refrigerant and a refrigeration cycle. The air conditioner 13 includes an electric motor 12 for driving a compressor. The air conditioner 13 has piping.

[0053] The vibration-suppression target pipe 14 is a pipe that is a target of vibration suppression control among the pipes of the air conditioner. For the vibration suppression control, a vibration detection unit 15 (sensor) is provided in the vibration-suppression target pipe 14.

[0054] The vibration detection unit 15 is installed on the vibration-suppression target pipe 14 and detects the degree of vibration of the vibration-suppression target pipe 14. Specifically, the vibration detection unit 15 may be any of an acceleration sensor, a velocity sensor, a displacement sensor, etc. The vibration detection unit 15 outputs an electrical signal representing the degree of vibration. In other words, the pipe vibration detection signal is a signal resulting from the detection of the degree of vibration of the pipe. The dimension of the numerical value represented by the pipe vibration detection signal is a dimension according to the type of sensor, such as acceleration, velocity, or displacement.

[0055] 2 is a schematic diagram showing an example of the installation location of the vibration detection unit 15 in this embodiment. As shown in the figure, the vibration detection unit 15 is attached to the piping 14 that is the vibration suppression target. In other words, the vibration detection unit 15 is installed so as to be able to detect piping vibrations that have vibration characteristics, such as resonance frequencies, that are different from the vibrations of the compressor itself and the vibrations of the piping near the compressor. The piping vibration suppression function of the vibration suppression control unit 16 performs control based on the vibration signal output by the vibration detection unit 15 that is attached to the piping that is the vibration suppression target (the vibration suppression target piping 14).

[0056] In FIG. 2 , reference numeral 41 denotes a compressor, and reference numeral 42 denotes a suction cup. In the piping connected to the compressor 41, it is desirable to install the vibration detection unit 15 at the end of at least the first bend counting from the compressor 41, which is the end of the piping path to the compressor that has the longer length, and at subsequent bends or straight sections. The example installation location of the vibration detection unit 15 shown in FIG. 2 is one such installation location. In other words, the piping (the piping to be vibration-suppressed) has a first piping end 61, a second piping end 62, one or more straight sections 63, and one or more bends 64. The first piping end 61 is connected to the compressor 41. The second piping end 62 is located on the opposite side from the first piping end 61 in the extension direction E of the piping. The one or more straight sections 63 are located between the first piping end 61 and the second piping end 62. One or more bent portions 64 are located between the first pipe end 61 and the second pipe end 62. Reference numeral 63A denotes a straight portion of the one or more straight portions 63 that is located closest to the first pipe end 61 in the extension direction E. Reference numeral 64A denotes a bent portion of the one or more bent portions 64 that is located closest to the first pipe end 61 in the extension direction E. The bent portion 64A has a connection portion 65 connected to the straight portion 63A. In the example shown in FIG. 2 , the vibration detection unit 15 is installed at the connection portion 65. The vibration detection unit 15 detects pipe vibrations at a location on the pipe where the vibration detection unit 15 is installed and outputs a pipe vibration detection signal to the control unit. The location at which the vibration detection unit 15 is installed is not limited to the connection portion 65. The vibration detection unit 15 may be installed not only at the connection portion 65 but also at the bent portion 64 located between the connection portion 65 and the second pipe end 62. Furthermore, the vibration detection unit 15 may be installed in the straight portion 63 located between the connection portion 65 and the second pipe end 62. When there are multiple vibration detection units 15, the multiple vibration detection units 15 are installed at the locations described above.

[0057] FIG. 3 is a graph showing the relationship between the rotational speed of the motor and the pipe detection signal detected by the vibration detection unit 15. In FIG. 3, the horizontal axis represents the rotational speed, and the vertical axis represents the pipe vibration detection signal. As described above, the pipe vibration detection signal represents the degree of pipe vibration. The numerical dimension of the pipe vibration detection signal is a dimension depending on the type of sensor, such as acceleration, velocity, or displacement. The illustrated example graph shows how the pipe vibration detection signal changes depending on the rotational speed of the motor. Because pipes have natural vibration modes, the state of pipe vibration changes when the rotational speed of the motor changes. In the illustrated example graph, the pipe vibration detection signal peaks at a certain predetermined rotational speed. A predetermined tolerance is set for the pipe vibration detection signal (vertical axis) for control by the vibration suppression control unit 16.

[0058] In the region from start-up until the pipe vibration detection signal reaches the allowable value, the vibration suppression control unit 16 performs speed vibration suppression control. That is, in the region where the rotation speed of the motor is equal to or greater than 0 and equal to or less than the switching speed ω0, the value of the pipe vibration detection signal is equal to or less than the allowable value, and the vibration suppression control unit 16 performs speed vibration suppression control. Furthermore, in the region where the value of the pipe vibration detection signal is equal to or greater than the allowable value, the vibration suppression control unit 16 performs pipe vibration suppression control. That is, in the region where the rotation speed of the motor is equal to or greater than the switching speed ω0 and equal to or less than the switching speed ωa, the value of the pipe vibration detection signal is equal to or greater than the allowable value, and the vibration suppression control unit 16 performs pipe vibration suppression control. Furthermore, in the region where the value of the pipe vibration detection signal again becomes equal to or less than the allowable value, the vibration suppression control unit 16 performs speed vibration suppression control. That is, in the region where the rotation speed of the motor is equal to or greater than the switching speed ωa, the value of the pipe vibration detection signal is equal to or less than the allowable value, and the vibration suppression control unit 16 performs speed vibration suppression control.

[0059] Generally, the relationship between pipe vibration and motor rotation speed depends on the structure of the air conditioner. The relationship between these two is grasped in advance. This makes it possible to obtain pipe vibration characteristics (characteristics representing the relationship between the motor rotation speed and the pipe vibration detection signal) similar to those shown in FIG. 3 . Therefore, the control system 101 can control switching between the pipe vibration suppression function and the speed vibration suppression function based on the pipe vibration characteristics acquired in advance. The above-described method for determining the switching speed is merely an example. For example, if there is a rotation speed range in which speed vibration is significant, the switching speed may be determined according to that rotation speed range.

[0060] 4 is a block diagram showing an example of the functional configuration of the vibration suppression control unit 16 of this embodiment. The configuration of the vibration suppression control unit 16 shown in the figure corresponds to the case where only one pipe vibration detection signal is provided. In other words, the vibration suppression control unit 16 shown in the figure operates by receiving only one pipe vibration detection signal output by only one vibration detection unit 15 attached to the vibration-suppression target pipe 14 whose vibration is to be suppressed. In other words, the vibration suppression control unit 16 calculates the compensation current Iqcmp based on the pipe vibration detection signal output by the vibration detection unit 15, the estimated speed ωm^ output from the speed estimator 9, and the estimated mechanical angle θm^ output from the integrator 10.

[0061] As also shown in FIG. 4 , the vibration suppression control unit 16 is configured to include five functions: a vibration extraction unit 17, a vibration suppression index selection unit 18, a signal amplification unit 19, a piping vibration signal / velocity vibration signal switching unit 20, and a compensation amount generation unit 21.

[0062] The vibration extraction unit 17 extracts at least the amplitude and phase of the first-order component of the estimated mechanical angle θm^ from the received piping vibration detection signal and the velocity estimation value ωm^.

[0063] The vibration extraction unit 17 includes a piping signal vibration extraction unit 17a and a velocity signal vibration extraction unit 17b. The piping signal vibration extraction unit 17a extracts the amplitude and phase of the piping vibration signal. The velocity signal vibration extraction unit 17b extracts the amplitude and phase of the velocity vibration signal. The vibration extraction by each of the piping signal vibration extraction unit 17a and the velocity signal vibration extraction unit 17b can be achieved using techniques such as a discrete Fourier transform, a digital filter, or a peak hold circuit.

[0064] The output from the piping signal vibration extraction unit 17a is input to a vibration suppression index selection unit 18. The output from the speed signal vibration extraction unit 17b is input to a piping vibration signal / speed vibration signal switching unit 20.

[0065] The vibration suppression index selection unit 18 selects a vibration suppression index from a plurality of pipe vibration detection signals. However, when there is only one pipe vibration detection signal (i.e., when there is only one vibration detection unit 15), the vibration suppression index selection unit 18 does not perform any particular processing and simply outputs the input pipe vibration detection signal as is.

[0066] That is, the vibration suppression index selection unit 18 outputs the amplitude and phase of the pipe vibration signal. Of the outputs from the vibration suppression index selection unit 18, the amplitude of the pipe vibration signal is input to the signal amplification unit 19. That is, the vibration suppression index selection unit 18 passes the pre-amplified pipe vibration signal amplitude Avib0 to the signal amplification unit 19. In addition, the amplitude of the pipe vibration signal is input to the pipe vibration signal / velocity vibration signal switching unit 20.

[0067] 5 is a graph showing an example of signal waveforms when the input to the compensation amount generator 21 is switched from a pipe vibration signal to a velocity vibration signal, assuming that the signal amplifier 19 is not provided. In FIG. 5, (a) shows the waveform of the pipe vibration detection signal, and (b) shows the waveform of the estimated velocity ωm^. Also, (c) shows the waveforms of the pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm extracted by the vibration extractor 17. Also, (d) shows the vibration signal amplitude A input to the compensation amount generator 21. The horizontal axis of each of these graphs represents time. When switching between the pipe vibration signal and the velocity vibration signal, if there is a difference between the amplitude value of the pipe vibration signal and the amplitude value of the velocity vibration signal, as in (c) of this example, the vibration signal amplitude A input to the compensation amount generator 21 changes discontinuously. In other words, at the timing of "switching" on the time axis in the figure, the vibration signal amplitude A shown in (d) changes discontinuously. Such a discontinuous change in the vibration signal amplitude A leads to a sudden change in the compensation current output by the compensation amount generating unit 21, which may result in torque fluctuations and control instability.

[0068] In order to suppress discontinuous changes in the vibration signal amplitude A during control switching as shown in the example of Figure 5, it is desirable to use signal amplifier 19 (Figure 4) to reduce the difference between the vibration signal amplitude before control switching and the vibration signal amplitude after control switching.

[0069] FIG. 6 is a block diagram showing a schematic functional configuration of the signal amplifier 19. As shown in the figure, the signal amplifier 19 includes an amplifier 22. The amplifier 22 receives the pre-amplification pipe vibration signal amplitude Avib0, which is the output from the vibration suppression index selector 18, amplifies the pre-amplification pipe vibration signal amplitude Avib0, and outputs the amplified pipe vibration signal amplitude Avib as a result. The amplification factor (gain) of the amplifier 22 can be fixed. For example, the fixed amplification factor can be determined based on the results of pre-measurement of the pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm in the absence of the signal amplifier 19. Specifically, the amplification factor of the amplifier 22 can be set to the value obtained by dividing the velocity vibration signal amplitude Awm in the absence of the signal amplifier 19 by the pipe vibration signal amplitude Avib (i.e., Avib0) in the absence of the signal amplifier 19.

[0070] 7 is a graph showing an example of signal waveforms when the input to the compensation amount generator 21 is switched from a pipe vibration signal to a velocity vibration signal when the signal amplifier 19 is provided. In FIG. 7, (a) shows the waveform of the pipe vibration detection signal, and (b) shows the waveform of the estimated velocity ωm^. Also, (c) shows the waveforms of the pre-amplification pipe vibration signal amplitude Avib0 (dashed line graph), the post-amplification pipe vibration signal amplitude Avib (solid line graph), and the velocity vibration signal amplitude (solid line graph). That is, the pre-amplification pipe vibration signal amplitude Avib0 is amplified by the signal amplifier 19 to become the post-amplification pipe vibration signal amplitude Avib. The amplification factor of the signal amplifier 19 is appropriately set. As a result, the post-amplification pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm become approximately equal. If there is no large difference between the amplified pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm, there will be no discontinuous change in the output vibration signal amplitude A before and after switching, as shown in (d), or the discontinuous change in the vibration signal amplitude A will be small, making it possible to reduce the shock caused by switching.

[0071] 6, it was necessary to adjust the gain of the amplifier 22 in advance based on the results of previous measurements, etc. However, it is also possible to configure the device so that the gain of the amplifier is automatically adjusted.

[0072] Fig. 8 is a block diagram showing a modified functional configuration of the vibration suppression control unit 16. Unlike the configuration of Fig. 4, the configuration shown in Fig. 8 allows the signal amplifier 19 to acquire the speed vibration signal amplitude Awm, thereby enabling automatic adjustment of the amplification factor of the signal amplifier 19. In other words, the signal amplifier 19 acquires the speed vibration signal amplitude Awm output from the speed signal vibration extraction unit 17b and uses it to adjust the amplification factor. Except for this point, the configuration of the vibration suppression control unit 16 (modified) shown in Fig. 8 is the same as the configuration shown in Fig. 4.

[0073] Fig. 9 is a block diagram showing the internal functional configuration of the signal amplifier 19 in the vibration suppression control unit 16 (variable example) shown in Fig. 8. As shown in the figure, the signal amplifier 19 in this variant example includes an amplifier 23 (variable gain) and an gain adjustment unit 24.

[0074] 9 , the amplification factor adjuster 24 automatically adjusts the amplification factor of the amplifier 23 based on the ratio between the magnitude of the unamplified pipe vibration signal amplitude Avib0 acquired from the vibration suppression index selector 18 and the magnitude of the velocity vibration signal amplitude Awm acquired from the velocity signal vibration extractor 17b. That is, the amplification factor adjuster 24 performs a calculation to adjust the amplification factor of the amplifier 23 so that the amplification factor of the amplifier 23 becomes, for example, (Awm / Avib0). However, the procedure by which the amplification factor adjuster 24 adjusts the amplification factor will be described later with reference to a flowchart.

[0075] 8 and 9, the gain of the signal amplifier 19 is automatically adjusted. That is, in this vibration suppression control unit 16 (variation), there is no need to perform measurements or set the gain in advance.

[0076] 10 is a flowchart showing an example of a processing procedure for automatically adjusting the gain by the gain adjustment unit 24. The adjustment procedure will be described below with reference to this flowchart.

[0077] First, in step S1, the amplification factor adjuster 24 sets a threshold value δ. The threshold value δ may be a predetermined positive constant. Alternatively, the threshold value δ may be determined in advance. This threshold value δ is a value that represents the ratio of an allowable range for the ratio between the unamplified pipe vibration signal amplitude Avib0 and the velocity vibration signal amplitude Awm.

[0078] In step S2, the amplification factor adjuster 24 determines whether |(Avib0 / Awm)-1|≦δ based on the acquired values ​​of the pre-amplification pipe vibration signal amplitude Avib0 and the velocity vibration signal amplitude Awm. That is, the amplification factor adjuster 24 determines whether the ratio of the pre-amplification pipe vibration signal amplitude Avib0 to the velocity vibration signal amplitude Awm is sufficiently close to 1. Note that "||" represents the absolute value of a numerical value. If |(Avib0 / Awm)-1|≦δ is satisfied (step S2: YES), that is, if the ratio of the pre-amplification pipe vibration signal amplitude Avib0 to the velocity vibration signal amplitude Awm is sufficiently close to 1, the process proceeds to step S3. If |(Avib0 / Awm)-1|≦δ is not satisfied (step S2: NO), that is, if the ratio of the pre-amplification pipe vibration signal amplitude Avib0 to the velocity vibration signal amplitude Awm is not sufficiently close to 1, the process proceeds to step S4. That is, in step S2, the amplification factor adjustment unit 24 determines whether the error of the ratio of the unamplified piping vibration signal amplitude Avib0 to the velocity vibration signal amplitude Awm relative to 1 is equal to or less than the threshold value δ, and determines whether to execute the next process, step S3 or S4, depending on the result of the determination.

[0079] When the process proceeds to step S3, the amplification factor adjustment unit 24 sets the amplification factor Gacc of the amplifier 23 to 1.0. In other words, if the result of the determination in step S2 is that the error of the ratio value (Avib0 / Awm) from 1 is equal to or less than the threshold value δ, the amplification factor Gacc is set to 1.0. After this step is completed, the entire process of this flowchart is terminated.

[0080] When the process proceeds to step S4, the amplification factor adjustment unit 24 sets the amplification factor Gacc of the amplifier 23 to (Awm / Avib0). That is, if the result of the determination in step S2 is that the error of the ratio value (Avib0 / Awm) relative to 1 exceeds the threshold value δ, or if the result of the determination is that the error exceeds the threshold value, the amplification factor Gacc is set to (Awm / Avib0). After this step is completed, the entire process of this flowchart is terminated.

[0081] As a result, the amplifier 23 amplifies Avib0 using the gain Gacc set in either step S3 or S4 above. Note that the gain Gacc value may be less than 1 or may be greater than or equal to 1.

[0082] That is, by performing the processes in steps S1 to S4, the amplification factor Gacc of the amplifier 23 can be set to (Awm / Avib0) or a value close to it. Here, the value close to it is within a range expressed by the inequality (Awm / Avib0)(1-δ)≦Gacc≦(Awm / Avib0)(1+δ) using the positive set value δ.

[0083] FIG. 11 is a graph showing an example of a signal waveform when the input to the compensation amount generation unit 21 is switched from a pipe vibration signal to a velocity vibration signal when using the vibration suppression control unit 16 (variant example) described above with reference to FIGS. 8 and 9 .

[0084] In FIG. 11, (a) shows the waveform of the pipe vibration detection signal, and (b) shows the waveform of the estimated velocity ωm^. Also, (c) shows the waveforms of the pre-amplification pipe vibration signal amplitude Avib0 (dashed line graph), the post-amplification pipe vibration signal amplitude Avib (solid line graph), and the velocity vibration signal amplitude (solid line graph). That is, the pre-amplification pipe vibration signal amplitude Avib0 is amplified by the signal amplifier 19 to produce the post-amplification pipe vibration signal amplitude Avib. The amplification factor of the signal amplifier 19 is appropriately set. As a result, the post-amplification pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm become approximately equal. If there is no significant difference between the post-amplification pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm, as shown in (d), there is no discontinuous change in the output vibration signal amplitude A before and after switching, or the discontinuous change in the vibration signal amplitude A is small, making it possible to reduce the shock caused by switching.

[0085] The value of the amplified pipe vibration signal amplitude Avib shown in FIG. 11C differs before and after automatic adjustment of the gain. That is, before automatic adjustment of the gain (before the time of "gain adjustment start"), the value of Avib is equal to Avib0. In other words, the gain of the signal amplifier 19 before automatic adjustment of the gain is 1. Furthermore, after automatic adjustment of the gain (after the time of "switching"), the value of Avib is equal to (or nearly equal to) Awm. In other words, the gain of the signal amplifier 19 after automatic adjustment of the gain is (Awm / Aviv0) or a value close to that. In this example, the gain adjuster 24 in the signal amplifier 19 adjusts the gain so that the gain changes smoothly before and after changing the signal gain. That is, after the time of "gain adjustment start" and before the time of "switching", the amplification factor is gradually changed to near (Awm / Aviv0) so that the value of Aviv does not change suddenly. Note that the change in the amplification factor in the signal amplifier 19 may be smooth (in other words, linear with respect to the passage of time) as shown in the graph of Fig. 11(c), or alternatively, may be changed in a step-like (stage-like) manner.

[0086] As described above, the amplification factor adjustment unit 24 in the signal amplifier 19 automatically adjusts the amplification factor, eliminating the need to manually calculate or set the amplification factor, and also making it possible to suppress the occurrence of switching shock in the vibration signal amplitude A as shown in FIG. 11(d).

[0087] The vibration suppression control unit 16 has been described above for the configurations shown in Fig. 4 and 8. In both the configurations shown in Fig. 4 and 8, the pipe vibration signal / velocity vibration signal switching unit 20 switches between pipe vibration suppression control and velocity vibration suppression control. The amplified pipe vibration signal amplitude Avib, the velocity vibration signal amplitude Awm, the pipe vibration signal phase, and the velocity vibration signal phase are input to the pipe vibration signal / velocity vibration signal switching unit 20. Based on these inputs, the pipe vibration signal / velocity vibration signal switching unit 20 outputs the vibration signal amplitude A and the vibration signal phase. The vibration signal amplitude A is either the amplified pipe vibration signal amplitude Avib or the velocity vibration signal amplitude Awm. The vibration signal phase is either the pipe vibration signal phase or the velocity vibration signal phase.

[0088] 12 is a block diagram showing the internal functional configuration of the pipe vibration signal / speed vibration signal switching unit 20. As shown in the figure, the pipe vibration signal / speed vibration signal switching unit 20 includes a speed command unit 25, a vibration signal amplitude switching unit 26, and a vibration signal phase switching unit 27.

[0089] As described with reference to the example of Figure 3, the pipe vibration signal / speed vibration signal switching unit 20 switches between pipe vibration suppression control and speed vibration suppression control based on the rotational speed of the electric motor, using the switching speed ω0 and the switching speed ωa as references.

[0090] 12, the speed command unit 25 outputs a command value for the rotational speed of the electric motor. That is, the speed command unit 25 passes speed information to the vibration signal amplitude switching unit 26. The speed command unit 25 may use the estimated speed ωm^ output from the speed estimator 9, the average value of the estimated speed ωm^ in the time direction, or the like.

[0091] The vibration signal amplitude switching unit 26 switches between the amplified pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm. The output from the vibration signal amplitude switching unit 26 is the vibration signal amplitude A. In other words, the vibration signal amplitude A is the one selected by the vibration signal amplitude switching unit 26, between the amplified pipe vibration signal amplitude Avib and the velocity vibration signal amplitude Awm. The vibration signal amplitude switching unit 26 switches based on the speed information passed from the velocity command unit 25. In other words, as illustrated in FIG. 3 , the vibration signal amplitude switching unit 26 selects and outputs the amplified pipe vibration signal amplitude Avib as the vibration signal amplitude A within a predetermined range related to the velocity. Furthermore, the vibration signal amplitude switching unit 26 selects and outputs the velocity vibration signal amplitude Awm as the vibration signal amplitude A within a range other than the above-mentioned "predetermined range" related to the velocity.

[0092] The vibration signal phase switching unit 27 switches between the pipe vibration signal phase and the velocity vibration signal phase. The output from the vibration signal phase switching unit 27 is the vibration signal phase. In other words, the vibration signal phase output from the vibration signal phase switching unit 27 is the one selected by the vibration signal phase switching unit 27, either the pipe vibration signal phase or the velocity vibration signal phase. The vibration signal phase switching unit 27 switches in conjunction with the vibration signal amplitude switching unit 26 described above. In other words, when the vibration signal amplitude switching unit 26 selects the amplified pipe vibration signal amplitude Avib, the vibration signal phase switching unit 27 selects and outputs the pipe vibration signal phase in conjunction with the amplified pipe vibration signal amplitude Avib. When the vibration signal amplitude switching unit 26 selects the velocity vibration signal amplitude Awm, the vibration signal phase switching unit 27 selects and outputs the velocity vibration signal phase in conjunction with the amplified pipe vibration signal amplitude Avib.

[0093] The pipe vibration signal / velocity vibration signal switching unit 20 configured as described above passes the vibration signal amplitude A and the vibration signal phase to the compensation amount generating unit 21 .

[0094] The compensation amount generator 21 receives the vibration signal amplitude A and the vibration signal phase passed from the pipe vibration signal / speed vibration signal switcher 20 as input, and outputs a compensation amount for vibration suppression. In this embodiment, a compensation current is used as the compensation amount. That is, the compensation amount generator 21 outputs a compensation current Iqcmp. In other words, the compensation amount generator 21 has a function of generating a compensation current synchronized with the pipe vibration signal or the speed vibration signal.

[0095] 13 is a block diagram showing a schematic internal functional configuration of the compensation amount generator 21. As shown in the figure, the compensation amount generator 21 includes a piping signal allowable value storage unit 28, a subtractor 29, a multiplier 30, a mechanical angular velocity command value supply unit 31, a repetition control unit 32, and a limiter 33.

[0096] The piping signal tolerance storage unit 28 stores the vibration signal tolerance Acpt at least temporarily.

[0097] The subtractor 29 performs subtraction to determine the difference between the vibration signal amplitude A and the vibration signal allowable value Acpt. The vibration signal amplitude A is a value passed from the piping vibration signal / speed vibration signal switching unit 20. The vibration signal allowable value Acpt is a value read out from the piping signal allowable value storage unit 28. In other words, the subtractor 29 performs the calculation expressed by the following equation (12).

[0098] A-Acpt...(12)

[0099] The subtractor 29 passes the calculation result of equation (12) to the multiplication unit 30 .

[0100] The multiplication unit 30 multiplies the output value from the subtractor 29 by a predetermined amplification factor k1 and the cosine of the vibration signal phase. That is, the multiplication unit 30 performs the calculation expressed by the following equation (13), where θ is the vibration signal phase.

[0101] k1(A-Acpt)cosθ...(13)

[0102] The multiplication unit 30 passes the calculation result of equation (13) to the repetition control unit 32 .

[0103] The mechanical angular velocity command value supply unit 31 supplies a mechanical angular velocity command value.

[0104] The repetitive control unit 32 executes repetitive control synchronized with the mechanical angular velocity command value, using the calculation result of the multiplication unit 30 as the command value. This generates and outputs the compensation current Iqcmp. The operation by the repetitive control unit 32 can be expressed, for example, by the transfer function of equation (14).

[0105] exp(-s・k2) / (1-exp(-s・T))...(14)

[0106] In equation (14), s is a complex number. Furthermore, k2 is a phase lead adjustment gain. The phase lead adjustment gain k2 is an adjustable parameter, and may be adjusted using an automatic adjustment function. Furthermore, T is the period of the vibration signal calculated by the following equation (15). Furthermore, exp( ) is an exponential function. In equation (15), ωmRef is a mechanical angular velocity command value.

[0107] T=2π / ωmRef (15)

[0108] The repetitive control unit 32 may be realized by another controller such as a proportional-integral control unit as long as it can generate a compensation current. The compensation current generated by the repetitive control unit 32 is input to a limiter 33 that limits the upper or lower limit of the output.

[0109] The limiter 33 limits the upper or lower limit of the compensation current generated by the repetitive control unit 32. By providing such a limiter 33, it is possible to suppress the output of an excessive compensation current that may destabilize the control system. The compensation current Iqcmp output from the limiter 33 is the final output from the compensation amount generation unit 21.

[0110] Fig. 14 is a block diagram showing a schematic functional configuration of a modified compensation amount generator 21. In this modified compensation amount generator 21, two or more vibration signal allowable values ​​are prepared, and the corresponding allowable values ​​are switched in conjunction with the switching performed by the pipe vibration signal / velocity vibration signal switcher 20. In other words, while the pipe vibration signal / velocity vibration signal switcher 20 described with reference to Fig. 13 uses the amplifier for the pipe vibration signal amplitude in the signal amplifier 19 as a unit for suppressing switching shock caused by switching, the modified compensation amount generator 21 of Fig. 14 suppresses switching shock in a different way.

[0111] 14, the compensation amount generating unit 21 according to this modification includes a piping signal allowable value storage unit 28, a vibration signal allowable value switching unit 39, a subtractor 29, a multiplier 30, a mechanical angular velocity command value supply unit 31, a repetition control unit 32, and a limiter 33. The compensation amount generating unit 21 according to this modification is characterized in that it switches between a plurality of (N, N≧2) vibration signal allowable values ​​as appropriate and operates using each of the plurality of allowable values.

[0112] That is, in this modified example, the piping signal allowable value storage unit 28 stores a first vibration signal allowable value, a second vibration signal allowable value, . . . , and an Nth vibration signal allowable value (N≧2).

[0113] Furthermore, the vibration signal allowable value switching unit 39 appropriately switches between the N vibration signal allowable values ​​stored in the piping signal allowable value storage unit 28. Specifically, the vibration signal allowable value switching unit 39 selects the corresponding vibration signal allowable value in conjunction with switching by the piping vibration signal / velocity vibration signal switching unit 20. In other words, the vibration signal allowable value switching unit 39 passes an appropriately selected vibration signal allowable value Acpt from the N vibration signal allowable values ​​from the first vibration signal allowable value to the Nth vibration signal allowable value to the subtractor 29. The subtractor 29 and each subsequent processing unit operate based on the vibration signal allowable value Acpt passed from the vibration signal allowable value switching unit 39.

[0114] The compensation amount generator 21 according to this modification generates and outputs the compensation current Iqcmp based on this vibration signal tolerance value Acpt. That is, the compensation amount generator 21 according to this modification generates and outputs the compensation current Iqcmp by switching the corresponding tolerance value in conjunction with the switching of the pipe vibration signal / speed vibration signal switching unit 20. The compensation amount generator 21 according to this modification prepares a plurality of tolerance values, for example, a tolerance value related to the pipe vibration signal and a tolerance value related to the speed vibration signal, and can prevent the magnitude of the compensation current Iqcmp from fluctuating greatly before and after switching by the pipe vibration signal / speed vibration signal switching unit 20. That is, it is possible to suppress shock due to switching.

[0115] As described above, the configuration of the first embodiment (including the modified examples) has both a pipe vibration suppression function and a speed vibration suppression function when there is only one pipe vibration detection signal (when the vibration detection unit 15 is provided in only one location), and can switch between pipe vibration suppression control and speed vibration suppression control while suppressing the switching shock.

[0116] Second Embodiment Next, a second embodiment will be described. Note that the description of the matters already described in the previous embodiment may be omitted. Here, the description will focus on matters unique to this embodiment.

[0117] This embodiment corresponds to the case where there are a plurality of piping vibration detection signals. In this embodiment, the processing in the vibration suppression index selection unit 18 differs from that in the first embodiment.

[0118] Air conditioning systems have complex piping arrangements, which means that the motor rotation speed at which vibration peaks become apparent can vary depending on the location and direction of the piping.

[0119] FIG. 15 is a graph showing the relationship between the rotational speed of the motor and the pipe detection signals detected by the vibration detection unit 15 at multiple locations on the pipe (specifically, two locations in this figure). In this figure, the horizontal axis represents the rotational speed, and the vertical axis represents the pipe vibration detection signal. The graph in this figure shows a case where two vibration peaks (P and Q) selected on the pipe are apparent at different rotational speeds. In the example shown in this figure, the first pipe vibration detection signal (peak P) has a value equal to or less than the allowable value in the range where the rotational speed is equal to or greater than 0 and equal to or less than the switching speed ω0. This first pipe vibration detection signal has a value equal to or greater than the allowable value in the range where the rotational speed is equal to or greater than the switching speed ω0 and equal to or less than the switching speed ωa. This first pipe vibration detection signal also returns to a value equal to or less than the allowable value in the range where the rotational speed is equal to or greater than the switching speed ωa. Furthermore, the second pipe vibration detection signal (peak Q) has a value equal to or less than the allowable value in the range where the rotational speed is equal to or greater than 0 and equal to or less than the switching speed ωa. The second piping vibration detection signal has a value equal to or greater than the allowable value in the region where the rotation speed is equal to or greater than the switching speed ωa and equal to or less than the switching speed ωc, and returns to a value equal to or less than the allowable value in the region where the rotation speed is equal to or greater than the switching speed ωc.

[0120] However, the number of vibration detectors 15 provided on the pipe is not limited to two, and may be three or more.

[0121] In the example shown in FIG. 15 , in the second embodiment, speed vibration suppression control is performed from startup (when the rotation speed is 0) until the switching speed ω0 at which the first piping vibration detection signal detected by the first vibration detection unit 15 (also referred to as vibration detection unit P) reaches the allowable value. Furthermore, the rotation speed is further increased, and pipe vibration suppression control based on the first piping vibration detection signal (peak P) is performed while the rotation speed is equal to or greater than the switching speed ω0 and equal to or less than the switching speed ωa. Furthermore, the rotation speed is further increased, and pipe vibration suppression control based on the second vibration detection unit 15 (vibration detection unit Q) is performed while the rotation speed is equal to or greater than the switching speed ωa and equal to or less than the switching speed ωc at which the second piping vibration detection signal detected by the second vibration detection unit 15 (also referred to as vibration detection unit Q) reaches the allowable value. Furthermore, speed vibration suppression control is performed in the range where the rotation speed is equal to or greater than the switching speed ωc.

[0122] Fig. 16 is a block diagram showing a schematic functional configuration of the vibration suppression control unit 16 for switching between pipe vibration suppression control and speed pulsation suppression control based on a plurality of vibration detection signals as exemplified in Fig. 15. As shown in the figure, the vibration suppression control unit 16 of this embodiment is configured to include five functions: a vibration extraction unit 17, a vibration suppression index selection unit 18, a signal amplification unit 19, a pipe vibration signal / speed vibration signal switching unit 20, and a compensation amount generation unit 21.

[0123] The vibration extracting unit 17 includes a piping signal vibration extracting unit 17a and a velocity signal vibration extracting unit 17b.

[0124] The piping signal vibration extraction unit 17a acquires the pipe vibration detection signal acquired from the vibration detection unit P and the pipe vibration detection signal acquired from the vibration detection unit Q, and extracts the pipe vibration signal amplitude and the pipe vibration signal phase of each of these signals, as in the first embodiment. The amplitude and phase of the pipe vibration detection signal acquired from the vibration detection unit P are defined as the pipe vibration signal amplitude P and the pipe vibration signal phase P, respectively. Furthermore, the amplitude and phase of the pipe vibration detection signal acquired from the vibration detection unit Q are defined as the pipe vibration signal amplitude Q and the pipe vibration signal phase Q, respectively. The piping signal vibration extraction unit 17a passes these four types of signals to the vibration suppression index selection unit 18.

[0125] The vibration suppression index selection unit 18 acquires the pipe vibration signal amplitude P, the pipe vibration signal phase P, the pipe vibration signal amplitude Q, and the pipe vibration signal phase Q from the pipe signal vibration extraction unit 17a. The vibration suppression index selection unit 18 selects either the pipe vibration signal amplitude P or the pipe vibration signal amplitude Q, and outputs the signal that has been selected as the pre-amplified pipe vibration signal amplitude Avib0. Furthermore, in conjunction with the selection of the pipe vibration signal amplitude P or the pipe vibration signal amplitude Q, the vibration suppression index selection unit 18 selects either the pipe vibration signal phase P or the pipe vibration signal phase Q, and outputs the signal that has been selected as the pipe vibration signal phase.

[0126] The functions and operations of the signal amplifier 19, pipe vibration signal / velocity vibration signal switcher 20, and compensation amount generator 21 in this embodiment are the same as those described in the first embodiment.

[0127] 17 is a block diagram showing a schematic functional configuration of the vibration suppression index selection unit 18 when a plurality of vibration detection signals are present. As shown in the figure, the vibration suppression index selection unit 18 of this embodiment is configured to include a speed command unit 34, a piping vibration signal amplitude switching unit 35, and a piping vibration signal phase switching unit 36. The functions of each unit are as follows:

[0128] The speed command unit 34 passes information on the value of the speed command to the pipe vibration signal amplitude switching unit 35. Note that the information on the value of the speed command may be the estimated speed ωm^ estimated by the speed estimating unit 9 or its average value.

[0129] The pipe vibration signal amplitude switching unit 35 switches between the pipe vibration signal amplitude P and the pipe vibration signal amplitude Q based on the value of the speed command passed from the speed command unit 34. The pipe vibration signal amplitude switching unit 35 outputs the signal of the selected pipe vibration signal amplitude as the pre-amplified pipe vibration signal amplitude Avib0.

[0130] The pipe vibration signal phase switching unit 36 ​​switches between the pipe vibration signal phase P and the pipe vibration signal phase Q in conjunction with the switching by the pipe vibration signal amplitude switching unit 35. The pipe vibration signal phase switching unit 36 ​​outputs the pipe vibration signal phase of the selected side.

[0131] As described above, the vibration suppression index selector 18 of this embodiment can appropriately switch the vibration detection signal to be used for vibration suppression control even when the peaks of multiple vibration detection signals appear at different rotation speeds. In other words, the vibration suppression index is appropriately selected for all rotation speed ranges.

[0132] As a modified example of the vibration suppression index selector 18 in this embodiment, the vibration suppression index selector 18 may calculate the overall power of the piping vibration signal amplitudes extracted from the plurality of vibration detection signals and use this power as the suppression target for vibration suppression control. Specifically, the vibration suppression index selector 18 in this modified example may calculate the square root of the sum of squares of the piping vibration signal amplitudes extracted from the plurality of vibration detection signals and use the value of the square root of the sum of squares as the suppression target for vibration suppression control.

[0133] 18 is a block diagram showing a schematic functional configuration of the vibration suppression index selection unit 18 according to this modified example. As shown in the figure, the vibration suppression index selection unit 18 according to this modified example is configured to include a square-sum-square-root calculation unit 37 and a phase calculation unit 38. The functions of each unit are as described below. Note that the configuration shown in the figure corresponds to the case where the number of vibration detection signals is two. However, the number of vibration detection signals may be three or more.

[0134] The square-root sum of squares calculation unit 37 calculates the squares of the pipe vibration signal amplitudes P and Q passed from the pipe signal vibration extraction unit 17a and calculates their sum. The square-root sum of squares calculation unit 37 calculates the square root of the calculated sum. The square-root sum of squares calculation unit 37 outputs this calculation result (square root) as the pre-amplified pipe vibration signal amplitude Aviv0.

[0135] The phase calculation unit 38 executes the calculation expressed by the following equation (16).

[0136] Kp×cos(θP)+Kq×cos(θQ)...(16)

[0137] In equation (16), θP and θQ are the pipe vibration signal phase P and the pipe vibration signal phase Q, respectively. Kp and Kq are phase adjustment parameters. The phase calculation unit 38 outputs the calculation result of equation (16) as the pipe vibration signal phase.

[0138] As described above, the configuration of the second embodiment (including the modified examples) can perform control to suppress vibrations based on vibration detection signals detected by a plurality of vibration detection units.

[0139] Third Embodiment Next, a third embodiment of the present invention will be described. Note that the following description may omit the matters already described in the previous embodiments. Here, the description will focus on matters unique to this embodiment.

[0140] The feature of this embodiment is that by using a weighting coefficient that changes depending on the rotation speed, it is possible to continuously switch between the piping vibration suppression control and the speed pulsation suppression control.

[0141] 19 is a block diagram showing an example of the functional configuration of a vibration suppression control unit 16 according to this embodiment. As shown in the figure, the vibration suppression control unit 16 according to this embodiment is configured to include a vibration extraction unit 17, a vibration suppression index selection unit 18, a first signal amplification unit 19a and a second signal amplification unit 19b, a piping vibration signal / velocity vibration signal switching unit 20, and a compensation amount generation unit 21. Note that the configuration of this vibration suppression control unit 16 is based on the premise that the number of piping vibration detection signals detected by the vibration detection unit 15 is one. In other words, a single vibration detection unit 15 (sensor) is provided on the piping. The functions of each unit are as follows:

[0142] The vibration extraction unit 17 and the vibration suppression index selection unit 18 have the same functions and perform the same processes as those in the first embodiment (see also FIG. 4). That is, the vibration extraction unit 17 has a piping signal vibration extraction unit 17 a and a velocity signal vibration extraction unit 17 b.

[0143] The first signal amplifier 19a and the second signal amplifier 19b each amplify a signal. The first signal amplifier 19a amplifies the amplitude of the pipe vibration signal output from the vibration suppression index selector 18. On the other hand, the second signal amplifier 19b amplifies the amplitude of the speed vibration signal output from the speed signal vibration extractor 17b.

[0144] Specifically, the first signal amplifier 19a performs a calculation based on the following equation (17) to determine and output the amplified pipe vibration signal amplitude Avib.

[0145] Avib=Wvib×Avib0...(17)

[0146] In equation (17), Wvib is a weighting coefficient for the pipe vibration signal amplitude, and Avib0 is the pre-amplification pipe vibration signal amplitude passed from the vibration suppression index selection unit 18.

[0147] At the same time, the first signal amplifier 19a performs a calculation based on the following equation (18) to determine and output the phase of the piping vibration signal.

[0148] Wvib×cos(θvib)...(18)

[0149] In equation (18), θvib is the phase angle of the pipe vibration signal.

[0150] The first signal amplifier 19 a passes the calculated amplified pipe vibration signal amplitude Avib and pipe vibration signal phase to the pipe vibration signal / velocity vibration signal switcher 20 .

[0151] Similarly, the second signal amplifier 19b performs a calculation based on the following equation (19) to determine and output the amplified velocity vibration signal amplitude Awm.

[0152] Awm=Wwm×Awm0...(19)

[0153] In equation (19), Wwm is a weighting coefficient for the amplitude of the speed vibration signal, and Awm0 is the amplitude of the speed vibration signal before amplification passed from the speed signal vibration extraction unit 17b.

[0154] At the same time, the second signal amplifier 19b performs a calculation based on the following equation (20) to determine and output the phase of the piping vibration signal.

[0155] Wwm×cos(θwm)...(20)

[0156] In equation (20), θwm is the velocity vibration signal phase angle.

[0157] The second signal amplifier 19 b passes the calculated amplified velocity vibration signal amplitude Awm and velocity vibration signal phase to the pipe vibration signal / velocity vibration signal switcher 20 .

[0158] The weighting factors Wvib and Wwm will be explained later.

[0159] The pipe vibration signal / velocity vibration signal switching unit 20 of this embodiment determines and outputs the vibration signal amplitude A and the vibration signal phase by processing specific to this embodiment. The functional configuration of the pipe vibration signal / velocity vibration signal switching unit 20 of this embodiment will be described later with reference to another figure.

[0160] The compensation amount generator 21 has the same functions as that in the first embodiment and performs the same processing (see also FIG. 4).

[0161] 20 is a block diagram showing a schematic functional configuration of the pipe vibration signal / velocity vibration signal switching unit 20 of this embodiment. As shown in the figure, the pipe vibration signal / velocity vibration signal switching unit 20 of this embodiment is configured to include an adder 40a and an adder 40b.

[0162] The adder 40a calculates the sum of the amplified pipe vibration signal amplitude Avib and the amplified velocity vibration signal amplitude Awm passed from the upstream side, and outputs the vibration signal amplitude A. As already explained, the amplified pipe vibration signal amplitude Avib and the amplified velocity vibration signal amplitude Awm are weighted using the weighting coefficients Wvib and Wwm, respectively.

[0163] The adder 40b calculates the sum of the phase of the pipe vibration signal and the phase of the velocity vibration signal passed from the upstream side, and outputs the vibration signal phase. Note that the phase of the pipe vibration signal and the phase of the velocity vibration signal are weighted using the weighting factors Wvib and Wwm, respectively, as already described.

[0164] Here, a method for determining the weighting coefficients in this embodiment will be described. Each of the weighting coefficients Wvib and Wwm is determined by a weighting function that depends on the rotation speed. Wvib is a weighting coefficient by which the pre-amplified pipe vibration signal amplitude Avib0 is multiplied, and Wwm is a weighting coefficient by which the pre-amplified speed vibration signal amplitude Awm0 is multiplied. The weights Wvib and Wwm can change between the switching speeds ωa and ωb while always satisfying the relationship of the following equation (19):

[0165] Wvib+Wwm=1...(19)

[0166] FIG. 21 is a graph showing an example of the relationship between the values ​​of the weighting factors Wvib and Wwm. In this graph, the horizontal axis represents the rotation speed, and the vertical axis represents the value of the weighting factor. The above equation (19) always holds true over the entire range of rotation speeds. In this example graph, in the range where the rotation speed is equal to or greater than 0 and equal to the switching speed ωa, the value of the weighting factor Wvib is 1, and the value of the weighting factor Wwm is 0. Furthermore, in the range where the rotation speed is equal to or greater than the switching speed ωa and equal to or less than the switching speed ωb, the value of the weighting factor Wvib changes linearly from 1 to 0, and the value of the weighting factor Wwm changes linearly from 0 to 1. Furthermore, in the range where the rotation speed is equal to or greater than the switching speed ωb, the value of the weighting factor Wvib is 0, and the value of the weighting factor Wwm is 1.

[0167] The values ​​of the weighting factors Wvib and Wwm shown in this graph mean the following: In other words, in the region where the rotational speed is equal to or greater than 0 and equal to or less than the switching speed ωa, only piping vibration suppression control is performed. Also, in the region where the rotational speed is equal to or greater than the switching speed ωb, only speed vibration suppression control is performed. In the region between the two, where the rotational speed is equal to or greater than the switching speed ωa and equal to or less than the switching speed ωb, a transition is made between piping vibration suppression control and speed vibration suppression control. This transition is made in a manner where the values ​​of the weighting factors Wvib and Wwm change linearly with respect to the rotational speed.

[0168] Such switching between the piping vibration suppression control and the velocity vibration suppression control is matched when the piping vibration detection signal changes according to the example characteristics of FIG.

[0169] In this embodiment, the rotation speed for determining the weighting coefficient may be a speed command value or an average value of the estimated speed.

[0170] FIG. 22 is a graph showing example waveforms of the speed command value, the weighting coefficients Wvib and Wwm, the pipe vibration signal amplitudes Avib0 and Avib before and after amplification, the speed vibration signal amplitudes Awm0 and Awm before and after amplification, and the vibration signal amplitude A in this embodiment. In each of (a), (b), (c), and (d) of the figure, the horizontal axis represents time. FIG. 22(a) shows the time change of the speed command value. FIG. 22(b) shows the time change of the weighting coefficients Wvib and Wwm. In FIG. 22(a), the weighting coefficients begin to change when the rotation speed reaches the switching speed ωa. The change of the weighting coefficients ends when the rotation speed reaches ωb. FIG. 22(c) shows the time change of the pipe vibration signal amplitudes Avib0 and Avib before and after amplification, and the speed fluctuation signal amplitudes Awm0 and Awm before and after amplification. Here, the signals Avib0 and Awm0 before amplification are shown by dashed lines. The pipe vibration signal amplitude Avib and the speed fluctuation signal amplitude Awm after being amplified by the time-varying weighting coefficient are shown by solid lines. The vibration signal amplitude A calculated by the adder 40a of the pipe vibration signal / speed vibration signal switching unit 20 is shown in Figure 1(d). By introducing a weighting coefficient that changes depending on the rotational speed, the fluctuation signal amplitude A changes continuously from the start to the end of switching.

[0171] The configuration shown in Fig. 19 is based on the premise that a single vibration detection unit 15 (sensor) is provided in the piping. In other words, the configuration shown in Fig. 19 switches between piping vibration suppression control and speed vibration suppression control in response to one piping detection signal. As a modification, it can be expanded to switch between piping vibration suppression control and speed vibration suppression control in response to a plurality (two or more) piping detection signals.

[0172] 23 is a block diagram showing a schematic functional configuration of a vibration suppression control unit 16 according to a modified example for switching between pipe vibration suppression control and speed vibration suppression control for a plurality of pipe detection signals based on a weighting function corresponding to the rotational speed. Specifically, the vibration suppression control unit 16 of the vibration suppression control unit 16 (modified example) shown in the figure operates based on signals from two vibration detection units. That is, the vibration suppression control unit 16 (modified example) receives as input a first pipe vibration detection signal detected by a first vibration detection unit 15 (also referred to as vibration detection unit P) and a second pipe vibration detection signal detected by a second vibration detection unit 15 (also referred to as vibration detection unit Q).

[0173] As shown in the figure, this vibration suppression control unit 16 (variant example) is configured to include a vibration extraction unit 17, a vibration suppression index selection unit 18, a first signal amplification unit 19a, a second signal amplification unit 19b, a third signal amplification unit 19c, a piping vibration signal / velocity vibration signal switching unit 20, and a compensation amount generation unit 21.

[0174] In this configuration, the functions and operations of the vibration extraction unit 17 and the vibration suppression index selection unit 18 are the same as those already explained.

[0175] A feature of this vibration suppression control unit 16 (variant example) is that a first signal amplifier 19a amplifies the piping vibration signal amplitude P output from the vibration suppression index selection unit 18. Furthermore, a second signal amplifier 19b amplifies the piping vibration signal amplitude Q output from the vibration suppression index selection unit 18. Furthermore, a third signal amplifier 19c amplifies the velocity vibration signal amplitude output from the velocity signal vibration extraction unit 17b.

[0176] Specifically, the first signal amplifier 19a calculates the following equation (21) to determine and output the amplified piping vibration signal amplitude AvibP.

[0177] AvibP=WvibP×AvibP0 (21)

[0178] In the equation (21), WvibP is a weighting coefficient for the pipe vibration signal amplitude P. Furthermore, AvibP0 is the unamplified pipe vibration signal amplitude P passed from the vibration suppression index selection unit 18.

[0179] At the same time, the first signal amplifier 19a calculates the following equation (22) to determine and output the piping vibration signal phase P.

[0180] WvibP×cos(θvibP)...(22)

[0181] In the equation (22), θvibP is the phase angle of the pipe vibration signal based on the pipe detection unit P.

[0182] Furthermore, the second signal amplifier 19b calculates the amplified pipe vibration signal amplitude AvibQ by performing the calculation of the following equation (23), and outputs it.

[0183] AvibQ=WvibQ×AvibQ0 (23)

[0184] In the equation (23), WvibQ is a weighting coefficient for the pipe vibration signal amplitude Q. Furthermore, AvibQ0 is the unamplified pipe vibration signal amplitude Q passed from the vibration suppression index selection unit 18.

[0185] At the same time, the second signal amplifier 19b calculates the following equation (24) to determine and output the piping vibration signal phase Q.

[0186] WvibQ×cos(θvibQ)...(24)

[0187] In the equation (24), θvibQ is the phase angle of the pipe vibration signal based on the pipe detector Q.

[0188] The third signal amplifier 19c calculates the amplified velocity vibration signal amplitude Awm by performing the calculation of the following equation (25), and outputs it.

[0189] Awm=Wwm×Awm0...(25)

[0190] In equation (25), Wwm is a weighting coefficient for the amplitude of the speed vibration signal, and Awm0 is the amplitude of the speed vibration signal before amplification passed from the speed signal vibration extraction unit 17b.

[0191] At the same time, the third signal amplifier 19c calculates the following equation (26) to determine and output the phase of the piping vibration signal.

[0192] Wwm×cos(θwm)...(26)

[0193] In the equation (26), θwm is the phase angle of the velocity vibration signal passed from the velocity signal vibration extraction unit 17b.

[0194] The amplified pipe vibration signal amplitude AvibP and pipe vibration signal phase P, which are outputs from the first signal amplifier 19a, are passed to the pipe vibration signal / velocity vibration signal switching unit 20. Furthermore, the amplified pipe vibration signal amplitude AvibQ and pipe vibration signal phase Q, which are outputs from the second signal amplifier 19b, are passed to the pipe vibration signal / velocity vibration signal switching unit 20. Furthermore, the amplified velocity vibration signal amplitude Awm and velocity vibration signal phase, which are outputs from the third signal amplifier 19c, are passed to the pipe vibration signal / velocity vibration signal switching unit 20.

[0195] Based on these signals, the pipe vibration signal / velocity vibration signal switching unit 20 generates a vibration signal amplitude A and a vibration signal phase. The pipe vibration signal / velocity vibration signal switching unit 20 passes this vibration signal amplitude A and vibration signal phase to the compensation amount generating unit 21. The operation of the pipe vibration signal / velocity vibration signal switching unit 20 will be described later with reference to another figure.

[0196] The compensation amount generator 21 generates a compensation amount based on the vibration signal amplitude A and vibration signal phase passed from the pipe vibration signal / velocity vibration signal switcher 20. Specifically, the compensation amount generator 21 has the same configuration as that of the first embodiment (see FIG. 13 ) and operates in the same manner.

[0197] 24 is a block diagram showing a schematic internal functional configuration of the pipe vibration signal / velocity vibration signal switching unit 20 in this embodiment. As shown in the figure, this pipe vibration signal / velocity vibration signal switching unit 20 is configured to include an adder 40a and an adder 40b.

[0198] The adder 40a adds the amplified pipe vibration signal amplitude AvibP, the amplified pipe vibration signal amplitude AvibQ, and the amplified velocity vibration signal amplitude Awm, and outputs the sum as the vibration signal amplitude A. The adder 40a passes the calculated vibration signal amplitude A to the compensation amount generator 21.

[0199] The adder 40b adds the piping vibration signal phase P, the piping vibration signal phase Q, and the velocity vibration signal phase, and outputs the sum as the vibration signal phase. The adder 40b passes the calculated vibration signal phase to the compensation amount generator 21.

[0200] In the configuration described in Figure 23, the three weighting factors described are determined by weighting functions that depend on the rotation speed. The weighting factor WvibP is a weight multiplied by the pre-amplification pipe vibration signal amplitude AvibP0. The weighting factor WvibQ is a weight multiplied by the pre-amplification pipe vibration signal amplitude AvibQ0. The weighting factor Wwm is a weight multiplied by the pre-amplification velocity vibration signal amplitude Awm0.

[0201] 25 is a graph showing an example of changes in the weighting factors WvibP, WvibQ, and Wwm in response to the rotation speed. Note that the sum of the weighting factors WvibP, WvibQ, and Wwm is always 1.

[0202] As shown in the figure, for example, when the four switching speeds ωa, ωb, ωc, and ωd have the relationship ωa<ωb<ωc<ωd, the values ​​of the weighting factors WvibP, WvibQ, and Wwm may change according to the rotation speed as follows: That is, in a range where the rotation speed is equal to or greater than 0 and equal to or less than the switching speed ωa, the weighting factor WvibP is 1, and the weighting factors WvibQ and Wwm are each 0. Furthermore, in a range where the rotation speed is equal to or greater than the switching speed ωa and equal to or less than the switching speed ωb, the weighting factor Wwm is 0, and the weighting factors WvibP and WvibQ may change while always maintaining the relationship of the following equation (27).

[0203] WvibP+WvibQ=1 (27)

[0204] In addition, in a region where the rotation speed is equal to or greater than the switching speed ωb and equal to or less than the switching speed ωc, the weighting factor WvibQ is 1, and the weighting factors WvibP and Wwm are each 0. In a region where the rotation speed is equal to or greater than the switching speed ωc and equal to or less than the switching speed ωd, the weighting factor WvibP is 0, and the weighting factors WvibQ and Wwm may change while always maintaining the relationship of the following equation (28).

[0205] WvibQ+Wwm=1...(28)

[0206] In addition, in the region where the rotation speed is equal to or higher than the switching speed ωd, the weighting factor Wwm is 1, and the weighting factors WvibP and WvibQ are both 0.

[0207] Assume that the pipe vibration detection signal changes according to the characteristics shown in FIG. 15 . The example of change in the weighting coefficient value shown in FIG. 25 corresponds to a case where pipe vibration suppression control is performed in the rotational speed range where the pipe vibration detection signal exceeds the allowable value, and speed vibration suppression control is performed in other rotational speed ranges. That is, in the rotational speed range from 0 or more to the switching speed ωa or less, only pipe vibration suppression control based on the vibration detection unit P is performed. In the rotational speed range from the switching speed ωa or more to the switching speed ωb or less, pipe vibration suppression control based on the vibration detection unit P and pipe vibration suppression control based on the vibration detection unit Q are combined, and a transition between these two types of control is performed. In the illustrated example, the change in the weighting coefficient is linear with respect to the change in rotational speed. In the rotational speed range from the switching speed ωb or more to the switching speed ωc or less, only pipe vibration suppression control based on the vibration detection unit Q is performed. In the rotational speed range from the switching speed ωc or more to the switching speed ωd or less, pipe vibration suppression control based on the vibration detection unit Q and speed vibration suppression control are combined, and a transition between these two types of control is performed. Then, in the region where the rotation speed is equal to or higher than the switching speed ωd, only the speed vibration suppression control is performed.

[0208] The rotation speed for determining the weighting coefficient may be a speed command value or an average value of the speeds estimated by the speed estimator 9 .

[0209] Figure 26 is a graph showing example actual waveforms of the speed command value, the values ​​of the weighting coefficients WvibP, WvibQ, and Wwm, the pipe vibration signal amplitudes AvibP0 and AvibP before and after amplification, the pipe vibration signal amplitudes AvibQ0 and AvibQ before and after amplification, the velocity vibration signal amplitudes Awm0 and Awm before and after amplification, and the vibration signal amplitude A when control is performed by the vibration suppression control unit 16 configured as shown in Figure 23.

[0210] In each of the graphs (a), (b), (c), and (d) in FIG. 26, the horizontal axis represents time. (a) in FIG. 26 shows the time change of the speed command value. (b) in FIG. 26 shows the time change of the weighting factors WvibP, WvivQ, and Wwm. The weighting factors WvibP, WvivQ, and Wwm shown in (b) in FIG. 26 change in response to the change in the speed command value shown in (a). In other words, when the rotation speed crosses the switching speeds ωa, ωb, ωc, and ωd, the weighting factors WvibP, WvivQ, and Wwm change in different ways. (c) in FIG. 26 shows the time change of the pipe vibration signal amplitudes AvibP0 and AvibP before and after amplification, the pipe vibration signal amplitudes AvibQ0 and AvibQ before and after amplification, and the speed fluctuation signal amplitudes Awm0 and Awm before and after amplification. Here, the signals AvibP0, AvibQ0, and Awm0 before amplification are each shown by a dashed line. The pipe vibration signal amplitudes AvibP and AvibQ and the speed fluctuation signal amplitude Awm after being amplified by the time-varying weighting coefficient are shown by a solid line. The vibration signal amplitude A calculated by the adder 40a of the pipe vibration signal / speed vibration signal switching unit 20 is shown in Figure 1(d). By introducing a weighting coefficient that changes depending on the rotational speed, the fluctuation signal amplitude A changes continuously from the start to the end of switching.

[0211] FIG. 26(b) will be explained in more detail. In the region where the rotation speed is equal to or greater than 0 and equal to or less than the switching speed ωa, the values ​​of the weighting factors are constant. In the region where the rotation speed is equal to or greater than the switching speed ωa and equal to or less than the switching speed ωb, the weighting factors WvibP and WvibQ change, and the weighting factor Wwm is constant. In the region where the rotation speed is equal to or greater than the switching speed ωb and equal to or less than the switching speed ωc, the values ​​of the weighting factors are constant. In the region where the rotation speed is equal to or greater than the switching speed ωc and equal to or less than the switching speed ωd, the weighting factors WvibQ and Wwm change, and the weighting factor WvibP is constant. In the region where the rotation speed is equal to or greater than the switching speed ωd, the values ​​of the weighting factors are constant.

[0212] As described above, the configuration of the third embodiment (including the modified examples) allows the vibration signal amplitude A to change continuously when switching between pipe vibration suppression control and velocity vibration suppression control. In other words, it is possible to suppress switching shock. The configuration of the third embodiment functions effectively whether there is one pipe vibration detection signal or multiple (two or more) pipe vibration detection signals.

[0213] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described. Note that the description of the matters already described in the previous embodiments may be omitted below. Here, the description will focus on matters unique to this embodiment.

[0214] In the first, second, and third embodiments, the compensation amount generator 21 in the vibration suppression controller 16 generates the compensation current. In contrast, the fourth embodiment is characterized in that a compensation voltage is generated to correct the voltage command.

[0215] 27 is a block diagram showing an outline of the overall functional configuration of a control system according to this embodiment. As shown in the figure, the control system 104 includes a speed command unit 1, a speed control system 2, a current command correction unit 3, a voltage command correction unit 51, a dq / UVW coordinate converter 5, a modulation unit 6, an inverter 7 (INV), a UVW / dq coordinate converter 8, a speed estimation unit 9, an integrator 10, a pole logarithm multiplication unit 11, a vibration extraction unit 17, a vibration suppression index selection unit 18, a signal amplification unit 19, a pipe vibration signal / speed vibration signal switching unit 20, a compensation amount generation unit 21, and an air conditioner 13.

[0216] Of the components of the control system 104, the functions including the vibration extraction unit 17, the vibration suppression index selection unit 18, the signal amplification unit 19, the piping vibration signal / velocity vibration signal switching unit 20, and the compensation amount generation unit 21 may be collectively referred to as the vibration suppression control unit 16.

[0217] A feature of this embodiment is that vibration suppression control unit 16 generates compensation voltages Vdcmp and Vqcmp instead of compensation currents. Voltage command corrector 51 adds compensation voltages Vdcmp and Vqcmp to pre-correction voltage command values ​​Vd0 and Vq0 output by current command corrector 3, respectively.

[0218] The basic configuration of the vibration suppression control unit 16 in this embodiment can be realized basically based on any of the configurations shown in Figures 4, 8, 16, 19, and 23. However, a feature of the vibration suppression control unit 16 in this embodiment is that, unlike the first, second, or third embodiment, the output from the compensation amount generation unit 21 is not a compensation current Iqcmp but a compensation voltage Vdcmp, Vqcmp.

[0219] Fig. 28 is a block diagram showing a schematic functional configuration of the vibration suppression control unit 16 according to this embodiment. The configuration shown in Fig. 28 is based on the configuration of the vibration suppression control unit 16 shown in Fig. 8. However, the vibration suppression control unit 16 according to this embodiment may be configured based on any of Figs. 4, 16, 19, and 23 instead of the configuration shown in Fig. 8.

[0220] As shown in FIG. 28, a compensation amount generating section 21 included in the vibration suppression control section 16 generates and outputs compensation voltages Vdcmp and Vqcmp.

[0221] In the first, second, and third embodiments, a compensation current is generated as a compensation amount to correct the current command value. In such a configuration, the upper limit of the frequency that can be compensated for depends on the responsiveness of the current control system. In contrast, in this embodiment, the compensation amount generator 21 generates a compensation voltage to directly correct the voltage command value. In other words, in this embodiment, compensation can be performed for a relatively wider frequency band.

[0222] 29 is a block diagram showing a schematic functional configuration of the compensation amount generator 21 according to this embodiment. As shown in the figure, the compensation amount generator 21 according to this embodiment includes a piping signal allowable value storage unit 28, a subtractor 29, a multiplier 30, a mechanical angular velocity command value supplier 31, a repetitive controller 32, a pole pair number multiplier 52, a compensation voltage calculator 53, and a limiter 33. The functions of each unit are as follows:

[0223] The piping signal tolerance storage unit 28 stores information related to the vibration signal tolerance. The compensation amount generation unit 21 generates and outputs the d-axis compensation voltage Vdcmp and the q-axis compensation voltage Vqcmp based on the vibration signal tolerance Acpt read from the piping signal tolerance storage unit 28 and the vibration signal amplitude A passed from the piping vibration signal / speed vibration signal switching unit 20.

[0224] The process of operation from the repetitive control unit 32 generating the compensation current Iqcmp from the input vibration signal amplitude A and vibration signal phase is the same as that in the first embodiment, and therefore will not be described here.

[0225] The compensation voltage calculation unit 53 performs the calculations expressed in the following equations (29) and (30) to generate the d-axis compensation voltage Vdcmp0 before limiting and the q-axis compensation voltage Vqcmp0 before limiting, respectively.

[0226] Vdcmp0=-ω×Lq×Iqcmp (29)

[0227] Vqcmp0=R×Iqcmp+ω×Ψ...(30)

[0228] In the calculation performed by the compensation voltage calculation unit 53, the compensation current command Iqcmp is passed from the repetitive control unit 32. The electrical angle estimated speed ω is passed from the pole pair number multiplication unit 52. The pole pair number multiplication unit 52 obtains the electrical angle estimated speed ω by multiplying the mechanical angular velocity command value passed from the mechanical angular velocity command value supply unit 31 by the number of pole pairs of the motor. Furthermore, the constant R in equation (30) is the value of the stator resistance of the motor. Furthermore, Lq in equation (29) is the q-axis inductance. Furthermore, Ψ in equation (30) is the permanent magnet flux linkage. The compensation voltage calculation unit 53 passes the d-axis compensation voltage Vdcmp0 before limiting and the q-axis compensation voltage Vqcmp0 before limiting to the limiter 33.

[0229] The limiter 33 prevents the d-axis compensation voltage Vdcmp0 before limiting and the q-axis compensation voltage Vqcmp0 before limiting, which are passed from the compensation voltage calculation unit 53, from being too high or too low. That is, the limiter 33 sets at least either an upper limit or a lower limit for the compensation voltage. This limits the voltage and prevents the control system from becoming unstable. The limiter 33 generates and outputs the d-axis compensation voltage Vdcmp and the q-axis compensation voltage Vqcmp, which are the final compensation amounts, as a result of applying at least one of the upper limit and the lower limit.

[0230] As described above, with the configuration of the fourth embodiment, the control system 104 generates the compensation voltage as described above and performs vibration suppression by correcting the voltage command value. According to the fourth embodiment, it is expected that it will be possible to compensate for vibrations over a wider frequency band than in the embodiments (first, second, and third embodiments) in which a compensation current is used.

[0231] The features of the above-described embodiments can be summarized as follows.

[0232] As a first feature, as shown in FIGS. 1 and 27 , in a configuration common to all embodiments (including modified examples), the control system (101, 104) includes an electric motor, an inverter, a vibration detection device (vibration detection unit, sensor), and a control unit. The electric motor is built into the compressor. The inverter drives the electric motor. The vibration detection device is installed in a pipe connected to the compressor and having one or more straight sections and one or more bends. The vibration detection device is installed at an end of the first bend farther from the compressor as viewed from the compressor side, or at a bend or straight section farther from the end as viewed from the compressor side. The vibration detection device detects pipe vibration at the installation location and outputs a pipe vibration detection signal. The control unit controls the inverter to suppress pipe vibration based on the pipe vibration detection signal output from the vibration detection device. With this configuration, the control system detects vibrations in the piping (the portion of the piping where the vibration detection device is installed, the piping to be vibration-suppressed) detected by the vibration detection device, and controls the inverter to suppress the piping vibration based on a piping vibration detection signal that represents the piping vibration. In other words, the control system controls to suppress the piping vibration caused by the vibration of the compressor that is operated by the rotation of the electric motor.

[0233] As a second feature, in the above-described control system configuration, as shown in Figures 1, 4, 8, 16, 19, 23, 27, and 28, the control unit includes a vibration extraction unit, a signal amplifier unit, a pipe vibration signal / speed vibration signal switching unit, and a compensation amount generator. The vibration extraction unit, signal amplifier unit, pipe vibration signal / speed vibration signal switching unit, and compensation amount generator may be collectively referred to as a vibration suppression control unit. The vibration extraction unit extracts at least the amplitude and phase of a speed vibration signal of a first-order mechanical angle component from the rotational speed signal of the electric motor, and extracts at least the amplitude and phase of a pipe vibration signal of a first-order mechanical angle component from the pipe vibration detection signal. The signal amplifier unit amplifies the speed vibration signal amplitude or the pipe vibration signal amplitude extracted by the vibration extraction unit. The pipe vibration signal / speed vibration signal switching unit selects either the speed vibration signal amplitude extracted by the vibration extraction unit or the pipe vibration signal amplitude amplified by the signal amplifier, or selects either the pipe vibration signal amplitude extracted by the vibration extraction unit or the speed vibration signal amplitude amplified by the signal amplifier, and outputs the selected speed vibration signal amplitude or the pipe vibration signal amplitude and the speed vibration signal phase or the pipe vibration signal phase corresponding to the selected speed vibration signal amplitude or the pipe vibration signal amplitude. The compensation amount generating unit generates and outputs a compensation amount for controlling the inverter based on (a) the speed vibration signal amplitude and the speed vibration signal phase, or (b) the pipe vibration signal amplitude and the pipe vibration signal phase, output from the pipe vibration signal / speed vibration signal switching unit. That is, the control unit generates a compensation amount for suppressing vibration based on the pipe vibration detection signal. The control unit controls the inverter using this compensation amount, thereby enabling vibration suppression. The rotational speed signal of the electric motor may be a signal of an estimated rotational speed or a signal of a rotational speed command value.

[0234] As a third feature, as shown in Figures 16, 23, etc., the control unit described as the second feature may further include a vibration suppression index selection unit. That is, there are a plurality of pipe vibration detection signals. The control unit further includes a vibration suppression index selection unit. The vibration suppression index selection unit determines an index for vibration suppression control from one of the plurality of pipe vibration detection signals and outputs the determined pipe vibration detection signal. Within the control unit, each unit after the signal amplification unit operates using the pipe vibration detection signal output by the vibration suppression index selection unit. This makes it possible to detect vibrations at a plurality of locations in the pipe and suppress vibrations based on the characteristics corresponding to each location.

[0235] As a fourth feature, as shown in FIG. 18 etc., the control unit described as the second feature may further include a vibration suppression index selection unit for calculating the square root of the sum of the squares of the signals. In other words, there are a plurality of pipe vibration detection signals. The control unit includes a vibration suppression index selection unit. This vibration suppression index selection unit calculates the square root of the sum of the squares of the pipe vibration signal amplitudes of each of the plurality of pipe vibration detection signals and outputs the pipe vibration detection signal of the square root. Then, within the control unit, each unit after the signal amplification unit operates using the pipe vibration detection signal output by the vibration suppression index selection unit. In this way, vibrations at a plurality of locations in the pipe can be detected and vibrations can be suppressed based on the characteristics corresponding to each location.

[0236] As a fifth feature, as shown in Figures 1, 4, 8, 13, 14, 16, 19, and 23, in the control unit described as the second feature, the compensation amount generation unit may generate and output a compensation current corresponding to the compensation amount. That is, the inverter can be controlled using this compensation current.

[0237] 27, 28, and 29, in the control unit described as the second feature, the compensation amount generation unit may generate and output a compensation voltage corresponding to the compensation amount. That is, the inverter can be controlled using this compensation voltage.

[0238] As a seventh feature, as also shown in FIGS. 9 and 10 , in the control unit described as the second feature, the signal amplifier automatically adjusts the amplification factor of the velocity vibration signal amplitude or the pipe vibration signal amplitude based on the velocity vibration signal amplitude before amplification and the pipe vibration signal amplitude before amplification. This allows the value of the ratio of the velocity vibration signal amplitude and the pipe vibration signal amplitude output as the amplified signals, obtained by dividing the velocity vibration signal amplitude by the pipe vibration signal amplitude, to be 1 or close to 1. In other words, the signal amplifier automatically adjusts the amplification factor of the signal based on the velocity vibration signal amplitude and the pipe vibration signal amplitude before amplification. The signal amplifier adjusts the amplification factor so that the value of the ratio calculated by (the velocity vibration signal amplitude / the pipe vibration signal amplitude) is equal to or greater than (1−δ) and equal to or less than (1+δ), where δ is a small positive value determined as appropriate. In addition, when adjustment of the amplification factor is not necessary (when the ratio calculated by (the amplitude of the velocity vibration signal / the amplitude of the piping vibration signal) before amplification is greater than or equal to (1-δ) and less than or equal to (1+δ)), the signal amplifier does not adjust the amplification factor and may set the amplification factor to 1, for example.

[0239] 3, 15, etc., in the control unit described as the second feature, the compensation amount generator may generate the compensation amount based on the speed vibration signal amplitude or the piping vibration signal amplitude so that the vibration signal amplitude is equal to or less than a predetermined vibration signal tolerance. In other words, the control system can switch between pipe vibration suppression control and speed vibration suppression control so that the vibration signal amplitude is equal to or less than the predetermined vibration signal tolerance.

[0240] 14 and the like, in the configuration of the eighth feature, the compensation amount generator may store the plurality of vibration signal allowable values, and generate the compensation amount so that the vibration signal amplitude is equal to or less than the vibration signal allowable value appropriately selected from the plurality of vibration signal allowable values. In other words, the control system can switch between piping vibration suppression control and velocity vibration suppression control so that the vibration signal amplitude is equal to or less than the vibration signal allowable value appropriately selected from the plurality of vibration signal allowable values.

[0241] As a tenth feature, as shown in Figures 19, 20, 21, 23, 24, and 25, the pipe vibration signal / speed vibration signal switching unit may weight and add (mix) the pipe vibration signal and the speed vibration signal using a predetermined weighting coefficient, instead of switching completely between the pipe vibration signal and the speed vibration signal. In other words, the pipe vibration signal / speed vibration signal switching unit switches between the pipe vibration signal and the speed vibration signal, but may add the two signals using a weighting coefficient when switching (transitioning). That is, in the configuration of the first feature, the control unit has a vibration extraction unit, a signal amplification unit, a pipe vibration signal / speed vibration signal switching unit, and a compensation amount generation unit. The vibration extraction unit extracts at least the amplitude and phase of the speed vibration signal of a first-order mechanical angle component from the rotational speed signal of the electric motor, and extracts at least the amplitude and phase of the pipe vibration signal of a first-order mechanical angle component from the pipe vibration detection signal. The signal amplifier amplifies the speed vibration signal amplitude and the one or more pipe vibration signal amplitudes extracted by the vibration extractor using an amplification factor based on a weighting coefficient that continuously changes with the rotational speed of the motor for each of the speed vibration signal amplitude and the one or more pipe vibration signal amplitudes, and amplifies the speed vibration signal phase and one or more pipe vibration signal phases using an amplification factor based on the weighting coefficient. The pipe vibration signal / speed vibration signal switcher adds the speed vibration signal amplitude amplified by the signal amplifier to the one or more pipe vibration signal amplitudes and outputs the result as a vibration signal amplitude, and adds the speed vibration signal phase amplified by the signal amplifier to the one or more pipe vibration signal phases and outputs the result as a vibration signal phase. The compensation amount generator generates and outputs a compensation amount for controlling the inverter based on the vibration signal amplitude and the vibration signal phase output from the pipe vibration signal / speed vibration signal switcher. This makes it possible to eliminate or mitigate shock caused by switching control.

[0242] As an eleventh feature, as shown in FIGS. 21 and 25 , the configuration of the tenth feature may be configured as follows. That is, in the specific range of the rotation speed, the weighting coefficient corresponding to only one of the speed vibration signal amplitude and one or more pipe vibration signal amplitudes is 1, and the weighting coefficients corresponding to the other amplitudes are 0. In the process of transitioning from the specific first range of the rotation speed to the specific second range of the rotation speed (which may be a transition in the direction of increasing or decreasing the rotation speed), the weighting coefficient of the amplitude corresponding to the first range continuously changes from 1 to 0, and the weighting coefficient of the amplitude corresponding to the second range continuously changes from 0 to 1. Furthermore, in all ranges of the rotation speed, the sum of the weighting coefficients corresponding to the respective amplitudes is 1. This makes it possible to eliminate or mitigate shock when switching control.

[0243] In other words, the value of each weighting factor is determined based on the rotation speed. When the weighting factors are changed continuously between 0 and 1, the weighting factors may be changed linearly with respect to the change in the rotation speed.

[0244] As a twelfth feature, as shown in FIG. 1 etc., in one aspect, a refrigeration cycle apparatus may include a compressor, an electric motor, an inverter, a vibration detection device, and a control unit. The compressor realizes a refrigeration cycle by compressing a gas. The electric motor is built in the compressor. The inverter drives the electric motor. One or more vibration detection devices are installed in a pipe connected to the compressor and having one or more straight sections and one or more bends. The vibration detection device is installed at an end of a first bend farther from the compressor as viewed from the compressor side, or in a bend or straight section farther from the end as viewed from the compressor side. The vibration detection device detects pipe vibration at the installation location and outputs a pipe vibration detection signal. The control unit controls the inverter to suppress vibration of the pipe based on the pipe vibration detection signal output from the vibration detection device.

[0245] As a thirteenth feature, in the configuration of the twelfth feature, the refrigeration cycle apparatus may include a plurality of the vibration detection devices, and each of the vibration detection devices may be attached to a predetermined position on the piping.

[0246] As a fourteenth feature, in the configuration of the twelfth or thirteenth feature, each of the vibration detection devices may be an acceleration sensor, a velocity sensor, or a displacement sensor. Any of these sensors detects the degree of vibration of the piping and outputs a signal representing the vibration.

[0247] In each of the above embodiments, the control system controls the electric motor 12 of the air conditioner 13. As a modification, the control system may control an electric motor generally provided in a refrigeration cycle device instead of any of the air conditioners 13 of the first to fourth embodiments. Generally, a refrigeration cycle device produces cold air or cold water by utilizing a refrigerant and a refrigeration cycle.

[0248] FIG. 30 is a schematic diagram illustrating the operation of a refrigeration cycle device. The compressor 41, suction cup 42, vibration-suppressed pipe 14, and vibration detection unit 15 (sensor) are as described with reference to FIG. 2 . The cycle shown in FIG. 30 is an example of a heat pump refrigeration cycle capable of heating and cooling. In FIG. 30 , a denotes a four-way valve. This four-way valve a changes the flow of refrigerant. b denotes a user-side heat exchanger. This user-side heat exchanger b functions as an evaporator / condenser. c denotes an expansion valve. This expansion valve c reduces the pressure of the refrigerant. d denotes a heat-source-side heat exchanger. This heat-source-side heat exchanger d functions as a condenser / evaporator. The solid and dashed arrows in FIG. 30 indicate the direction of fluid (refrigerant) flow within the pipes. That is, the refrigerant flows in the direction of the solid lines during cooling (cooling) and in the direction of the dashed lines during heating (heating). The direction of the refrigerant flow can be controlled by switching the four-way valve a. The refrigeration cycle device described here is an existing technology.

[0249] The compressor 41 is a device that compresses and sends out the refrigerant that is supplied to it. Specifically, the compressor 41 compresses the refrigerant that is sucked in through a suction cup 42, and sends out the compressed refrigerant to the user side.

[0250] FIG. 31 is a block diagram showing an example of the internal configuration of a computer when at least some of the functions of each of the first to fourth embodiments (including variations) are realized using a computer. That is, a computer can be used inside a device or component constituting a control system in each embodiment. As shown in the figure, the computer includes a central processing unit 901, a RAM 902, an input / output port 903, input / output devices 904 and 905, and a bus 906. The computer itself can be realized using existing technology. The central processing unit 901 executes instructions contained in a program read from the RAM 902 or the like. In accordance with each instruction, the central processing unit 901 writes data to the RAM 902, reads data from the RAM 902, and performs arithmetic and logical operations. The RAM 902 stores data and programs. Each element in the RAM 902 has an address and can be accessed using the address. Note that RAM stands for "random access memory." The input / output port 903 is a port through which the central processing unit 901 exchanges data with external input / output devices, etc. The input / output devices 904 and 905 are input / output devices. The input / output devices 904 and 905 exchange data with the central processing unit 901 via the input / output port 903. The bus 906 is a common communication path used within the computer. For example, the central processing unit 901 reads and writes data from the RAM 902 via the bus 906. Also, for example, the central processing unit 901 accesses the input / output port 903 via the bus 906.

[0251] At least some of the control functions in the above-described embodiments may be implemented by a computer and a program. In this case, the program for implementing this function may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. Note that the term "computer system" herein includes hardware such as an OS and peripheral devices. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, CD-ROMs, DVD-ROMs, and USB memory, as well as storage devices such as hard disks built into computer systems. In other words, a "computer-readable recording medium" may be a non-transitory computer-readable recording medium. Furthermore, the term "computer-readable recording medium" may also include media that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or telephone lines, or media that store programs for a fixed period of time, such as volatile memory within the computer systems that serve as the server or client in such cases. Furthermore, the above program may be one that realizes part of the functions described above, or may be one that can realize the functions described above in combination with a program already recorded in the computer system.

[0252] According to at least one of the embodiments described above, pipe vibrations are directly detected using the vibration detection unit 15 (sensor) provided in the pipe. As a result, even when pipe resonance is excited, control for suppressing pipe vibrations can be performed based on the vibration signal output by the vibration detection unit 15 (sensor). As a result, vibrations and noise of the entire refrigeration cycle system (air conditioner, etc.) can be suppressed.

[0253] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0254] 1...Speed ​​command unit, 2...Speed ​​control system, 3...Current command correction unit, 4...Current control system, 5...dq / UVW coordinate converter, 6...Modulation unit, 7...Inverter (INV), 8...UVW / dq coordinate converter, 9...Speed ​​estimation unit, 10...Integrator, 11...Pole pair multiplication unit, 12...Electric motor, 13...Air conditioner, 14...Pipe to be subjected to vibration suppression, 15...Vibration detection unit (vibration detection device), 16...Vibration suppression control unit, 17...Vibration extraction unit, 17 a...Pipe signal vibration extraction unit, 17b...Speed ​​signal vibration extraction unit, 18...Vibration suppression index selection unit, 19...Signal amplification unit, 19a...First signal amplification unit, 19b...Second signal amplification unit, 20...Pipe vibration signal / speed vibration signal switching unit, 21...Compensation amount generation unit, 22...Amplifier (fixed amplification factor), 23...Amplifier (variable amplification factor), 24...Amplification factor adjustment unit, 25...Speed ​​command unit, 26...Vibration signal amplitude switching unit, 27...Vibration signal phase Switching unit, 28...piping signal allowable value storage unit, 29...subtractor, 30...multiplier, 31...mechanical angular velocity command value supply unit, 32...repetitive control unit, 33...limiter, 34...speed command unit, 35...piping vibration signal amplitude switching unit, 36...piping vibration signal phase switching unit, 37...square root sum calculation unit, 38...phase calculation unit, 39...vibration signal allowable value switching unit, 40...adder, 40a...adder, 40b...adder, 41...compressor 42...suction cup, 51...voltage command correction unit, 52...pole pair number multiplication unit, 53...compensation voltage calculation unit, 61...first piping end, 62...second piping end, 63, 63A...straight section, 64, 64A...bent section, 65...connection section, 101...control system, 104...control system, 901...central processing unit, 902...RAM, 903...input / output port, 904, 905...input / output device, 906...bus

Claims

1. A refrigeration cycle apparatus comprising: an electric motor built in a compressor provided in the refrigeration cycle apparatus; an inverter that drives the electric motor; piping connected to the compressor; a vibration detection device installed on the piping that detects piping vibrations occurring in the piping and outputs a piping vibration detection signal; and a control unit that controls the inverter to suppress piping vibrations based on the piping vibration detection signal output from the vibration detection device, wherein the piping has: a first piping end connected to the compressor; a second piping end located opposite the first piping end in an extension direction of the piping; one or more straight sections located between the first piping end and the second piping end; and one or more bent sections located between the first piping end and the second piping end, wherein the bent section located closest to the first piping end in the extension direction of the one or more bent sections has a connection section connected to the straight section located closest to the first piping end in the extension direction of the one or more straight sections, and the vibration detection device detects the connection section, the bent section located between the connection section and the second piping end, and a straight section located between the connection section and the second pipe end, wherein the vibration detection device detects the pipe vibration at a point on the pipe where the vibration detection device is installed, and outputs a pipe vibration detection signal to the control section.

2. The control unit includes: a vibration extraction unit that extracts at least the speed vibration signal amplitude and speed vibration signal phase of a first-order mechanical angle component from the rotation speed signal of the motor, and extracts at least the pipe vibration signal amplitude and pipe vibration signal phase of the first-order mechanical angle component from the pipe vibration detection signal; a signal amplification unit that amplifies the speed vibration signal amplitude or the pipe vibration signal amplitude extracted by the vibration extraction unit; and a pipe vibration signal / speed vibration signal switching unit that selects either the speed vibration signal amplitude extracted by the vibration extraction unit or the pipe vibration signal amplitude amplified by the signal amplification unit, or selects either the pipe vibration signal amplitude extracted by the vibration extraction unit or the speed vibration signal amplitude amplified by the signal amplification unit, and outputs the speed vibration signal amplitude or the pipe vibration signal amplitude of the selected side and the speed vibration signal phase or the pipe vibration signal phase of the side corresponding to the selected speed vibration signal amplitude or the pipe vibration signal amplitude. a compensation amount generating unit that generates and outputs a compensation amount for controlling the inverter based on (a) the amplitude of the speed vibration signal and the phase of the speed vibration signal, or (b) the amplitude of the pipe vibration signal and the phase of the pipe vibration signal, which are output from the pipe vibration signal / speed vibration signal switching unit.

3. The control system according to claim 2, wherein the vibration detection device outputs a plurality of pipe vibration detection signals, and the control unit comprises a vibration suppression index selection unit that determines an index for vibration suppression control from one of the plurality of pipe vibration detection signals and outputs the determined pipe vibration detection signal, and the control system operates using the pipe vibration detection signal output by the vibration suppression index selection unit from the signal amplification unit onwards.

4. The control system according to claim 2, wherein the vibration detection device outputs a plurality of pipe vibration detection signals, and the control unit comprises a vibration suppression index selection unit that calculates the square root of the sum of the squares of the pipe vibration signal amplitudes of each of the plurality of pipe vibration detection signals and outputs the pipe vibration detection signal of the square root, and the control system operates using the pipe vibration detection signal output by the vibration suppression index selection unit from the signal amplification unit onwards.

5. The control system according to claim 2, wherein the compensation amount generating unit generates and outputs a compensation current corresponding to the compensation amount.

6. The control system according to claim 2, wherein the compensation amount generating unit generates and outputs a compensation voltage corresponding to the compensation amount.

7. The control system according to claim 2, wherein the signal amplifier automatically adjusts the amplification factor of the velocity vibration signal amplitude or the piping vibration signal amplitude based on the velocity vibration signal amplitude before amplification and the piping vibration signal amplitude before amplification, so that the value of the ratio obtained by dividing the velocity vibration signal amplitude by the piping vibration signal amplitude for the velocity vibration signal amplitude and the piping vibration signal amplitude output as the amplified signal becomes 1 or a value close to 1.

8. The control system according to claim 2, wherein the compensation amount generating unit generates the compensation amount based on the velocity vibration signal amplitude or the piping vibration signal amplitude so that the vibration signal amplitude is equal to or less than a predetermined vibration signal tolerance value.

9. The control system according to claim 8, wherein the compensation amount generating unit stores a plurality of vibration signal allowable values, and generates the compensation amount so that the vibration signal amplitude is equal to or less than a vibration signal allowable value appropriately selected from the plurality of vibration signal allowable values.

10. The control unit comprises: a vibration extraction unit that extracts at least the speed vibration signal amplitude and speed vibration signal phase of a first-order mechanical angle component from the rotation speed signal of the motor, and extracts at least the pipe vibration signal amplitude and pipe vibration signal phase of the first-order mechanical angle component from the pipe vibration detection signal; a signal amplification unit that amplifies the speed vibration signal amplitude and one or more pipe vibration signal amplitudes extracted by the vibration extraction unit using an amplification factor based on a weighting coefficient that changes continuously with the rotation speed of the motor for each of the speed vibration signal amplitude and one or more pipe vibration signal amplitudes, and amplifies the speed vibration signal phase and one or more pipe vibration signal phases using an amplification factor based on the weighting coefficient; a pipe vibration signal / speed vibration signal switching unit that adds the speed vibration signal amplitude and one or more pipe vibration signal amplitudes amplified by the signal amplification unit and outputs the result as a vibration signal amplitude, and adds the speed vibration signal phase amplified by the signal amplification unit and one or more pipe vibration signal phases and outputs the result as a vibration signal phase; a compensation amount generating unit that generates and outputs a compensation amount for controlling the inverter based on the vibration signal amplitude and the vibration signal phase output from the pipe vibration signal / velocity vibration signal switching unit.

11. The control system according to claim 10, wherein, in the specific region of the rotational speed, the weighting coefficient corresponding to only one of the speed vibration signal amplitude and one or more pipe vibration signal amplitudes is 1 and the weighting coefficient corresponding to the other amplitudes is 0, and in the process of transitioning from the specific first region of the rotational speed to the specific second region of the rotational speed, the weighting coefficient of the amplitude corresponding to the first region continuously changes from 1 to 0, and the weighting coefficient of the amplitude corresponding to the second region continuously changes from 0 to 1, and the sum of the weighting coefficients corresponding to each amplitude in all regions of the rotational speed is 1.

12. A system comprising: a compressor; an electric motor built in the compressor; an inverter that drives the electric motor; a pipe connected to the compressor; a vibration detection device that is installed on the pipe and detects pipe vibrations occurring in the pipe and outputs a pipe vibration detection signal; and a control unit that controls the inverter to suppress vibrations of the pipe based on the pipe vibration detection signal output from the vibration detection device, wherein the pipe has: a first pipe end connected to the compressor; a second pipe end located opposite the first pipe end in an extension direction of the pipe; one or more straight sections located between the first pipe end and the second pipe end; and one or more bent sections located between the first pipe end and the second pipe end, wherein the bent section located closest to the first pipe end in the extension direction of the one or more bent sections has a connection section connected to the straight section located closest to the first pipe end in the extension direction of the one or more straight sections, and the vibration detection device detects the connection section, the bent section located between the connection section and the second pipe end, and a straight portion located between the connection portion and the second pipe end, wherein the vibration detection device detects the pipe vibration at a portion of the pipe where the vibration detection device is installed, and outputs a pipe vibration detection signal to the control unit.

13. The refrigeration cycle apparatus according to claim 12, further comprising a plurality of vibration detection devices each corresponding to one of the vibration detection devices, each of the plurality of vibration detection devices being attached to the piping.

14. A refrigeration cycle apparatus according to claim 12 or 13, wherein the vibration detection device is any one of an acceleration sensor, a velocity sensor, and a displacement sensor.

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