Calculation system, magnetic bearing system, and refrigeration device

Abstract

A technique is provided that can obtain good frequency characteristics of a controlled object even at the site where the controlled object is used. [Solution] The calculation system 100 comprises a signal generating unit 30 that inputs an excitation signal from a magnetic bearing control device 10 to a magnetic bearing 20 to excite the magnetic bearing 20, and a calculation unit 512 that calculates the frequency response of part or all of the magnetic bearing control device 10 and the magnetic bearing 20 when the excitation signal is input to the magnetic bearing 20. The excitation signal is a split multi-sine signal that has, on different time axes, a first waveform formed by superimposing a plurality of sine waves with different frequencies, and a second waveform formed by superimposing a plurality of sine waves with different frequencies and which is a waveform different from the first waveform.

Description

[Technical Field]

[0001] The present disclosure relates to a computing system, a magnetic bearing system, and a refrigeration device. [Background technology]

[0002] When calculating the frequency response (transfer function) of a control device or a controlled object, the frequency of the excitation signal input to the control device and the controlled object is usually changed in sequence to calculate the frequency response of multiple frequencies. In this case, the frequencies are changed serially on the time axis, which increases the time required for calculation.

[0003] Therefore, Patent Document 1 discloses a servo analyzer that applies a wideband signal from a signal source of the servo analyzer to a system under test, calculates the spectrum of the measurement frequency band based on the applied wideband signal and the output of the system under test, and measures the transfer function. The wideband signal includes a multi-sine signal.

[0004] Patent Document 2 also discloses a frequency characteristic device that generates a multi-sine signal consisting of sine waves of multiple frequencies, inputs it to a control object (object to be measured), and calculates the frequency characteristics of the control object from sampling data of the input signal and sampling data of the output signal. Thus, conventionally, the time required for calculation has been shortened by outputting a multi-sine signal in which multiple frequencies are superimposed at once, and analyzing the input signal and output signal corresponding to the multi-sine signal in a calculation device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-94690 [Patent Document 2] Patent No. 7007318 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when a multi-sine signal is used as the signal to be applied to the control object, if the frequency band to be measured is wide or the number of frequencies is large, it is necessary to use a large computer or the like as the calculation device, which can perform a large number of calculations per unit time or has a large memory capacity.

[0007] On the other hand, there is a demand for measuring the frequency response at each site of use depending on the controlled object. If a large-scale computing device were to be brought into each of multiple sites of use to measure the frequency response, it would require time and cost to arrange, transport, and install the device, which would defeat the purpose of measuring the frequency response in a short time.

[0008] The present disclosure provides a technique that can obtain good frequency characteristics of a controlled object even at the site where the controlled object is used. [Means for solving the problem]

[0009] According to a first aspect of the present disclosure, a control device includes a signal generating unit that inputs an excitation signal from a control device to a controlled object to vibrate the controlled object, and a calculating unit that calculates the frequency response of the control device and part or all of the controlled object when the excitation signal is input to the controlled object, wherein the excitation signal is a split multi-sine signal having, on different time axes, a first waveform formed by superimposing a plurality of sine waves with different frequencies, and a second waveform formed by superimposing a plurality of sine waves with different frequencies and having a waveform different from the first waveform.

[0010] According to the above, the calculation system uses a divided multi-sine signal as an excitation signal when calculating the frequency response, and can input multiple waveforms having an appropriate number of sine waves to the control target by shifting them on the time axis depending on the performance of the calculation device. This makes it possible to efficiently obtain the frequency response of the control device and the control target depending on the performance of the calculation device. For example, the calculation system can obtain good frequency characteristics of the control target even in a site where the control target is used and where it is difficult to apply a high-performance calculation device.

[0011] Moreover, the signal generating section switches between all of the plurality of sine waves forming the first waveform and all of the plurality of sine waves forming the second waveform at the same timing.

[0012] In this way, by switching between all of the multiple sine waves of the first waveform and all of the multiple sine waves of the second waveform at the same time, the calculation system can easily manage the multiple sine waves for which frequency responses are calculated.

[0013] The signal generating section also switches from the first waveform to the second waveform by switching some of the plurality of sine waves forming the first waveform to sine waves with different frequencies.

[0014] In this way, by switching some of the sine waves that form the first waveform to sine waves with different frequencies, the calculation system can more efficiently calculate the frequency responses of all the sine waves.

[0015] Furthermore, the number of the plurality of sine waves forming the first waveform is the same as the number of the plurality of sine waves forming the second waveform.

[0016] In this way, by having the same number of sinusoids forming the first waveform as the same number of sinusoids forming the second waveform, the calculation system can more efficiently calculate the frequency responses of all sinusoids.

[0017] Furthermore, the signal generating unit sets a larger amplitude for a sine wave having a higher frequency among the plurality of sine waves of the divided multi-sine signal.

[0018] This allows the calculation system to calculate the frequency response well even for sine waves with high frequencies.

[0019] In addition, the frequency response includes characteristics of the amplitude ratio and phase difference between the input signal and the output signal, and the calculation unit calculates the amplitude ratio or the phase difference for each of a plurality of sine waves by performing a discrete Fourier transform on the input signal and the output signal acquired from the control device or the controlled object.

[0020] In this way, by performing a discrete Fourier transform, the calculation system can easily calculate the frequency response for each sine wave of multiple frequencies.

[0021] The calculation unit also calculates the amplitude ratio or the phase difference for each of the plurality of sine waves forming the first waveform by adding together values ​​calculated for each arbitrary time of the first waveform, and calculates the amplitude ratio or the phase difference for each of the plurality of sine waves forming the second waveform by adding together values ​​calculated for each arbitrary time of the second waveform.

[0022] In this way, in the discrete Fourier transform, the amplitude ratio or phase difference of the frequency responses can be calculated independently by adding up the values ​​calculated at any time for the first and second waveforms. As a result, used data can be immediately deleted, and an increase in the memory capacity of the calculation device can be suppressed.

[0023] The signal generating unit is provided inside the control device.

[0024] By providing the signal generating unit inside the control device in this way, the time and effort required to prepare a separate signal generating unit is eliminated, and the frequency response can be obtained more easily.

[0025] The signal generating unit is provided outside the control device.

[0026] By providing the signal generating unit outside the control device in this way, it is possible to prevent the control device from becoming larger in size.

[0027] The device also has a user setting unit that allows a user to set the frequency band or the number of frequencies of the vibration signal to be input to the controlled object, and the signal generating unit automatically sets the number of multiple sine waves included in the first waveform and the second waveform of the divided multi-sine signal based on the frequency band or the number of frequencies set by the user setting unit.

[0028] This allows the calculation system to reduce the load set by the user when acquiring the frequency response, and also makes it possible to appropriately generate divided multi-sine signals.

[0029] Furthermore, a second aspect of the present disclosure is a magnetic bearing system comprising the above-mentioned calculation system, a magnetic bearing that supports a rotating shaft in a non-contact manner, and a magnetic bearing control device that controls the magnetic bearing, wherein the controlled object is the magnetic bearing and the control device is the magnetic bearing control device.

[0030] This allows the calculation system to stably measure the frequency response of the magnetic bearing system.

[0031] A third aspect of the present disclosure is a refrigeration system comprising: a compressor having a magnetic bearing as a control target; a control device that controls the operation of the magnetic bearing; and a refrigerant circuit in which the compressor is provided and circulates a refrigerant based on the operation of the compressor, wherein the control device inputs an excitation signal to the magnetic bearing to excite the magnetic bearing, and causes a calculation unit to calculate the frequency response of part or all of the magnetic bearing and the control device when the excitation signal is input to the magnetic bearing, and the excitation signal is a split multi-sine signal having, on different time axes, a first waveform formed by superimposing a plurality of sine waves with different frequencies, and a second waveform formed by superimposing a plurality of sine waves with different frequencies and having a waveform different from the first waveform.

[0032] Even in this case, the refrigeration system can obtain good frequency characteristics of the magnetic bearing even at the site where the compressor is used. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a diagram illustrating the overall configuration of an air conditioning apparatus, which is a refrigeration apparatus according to an embodiment. [Figure 2] 1 is a diagram illustrating an overall configuration of a calculation system according to an embodiment. [Figure 3] FIG. 10 is a diagram illustrating an example of generation of a multisine signal. [Figure 4] FIG. 2 is an explanatory diagram showing a divided multisine signal according to a first example. [Figure 5] FIG. 10 is an explanatory diagram showing a divided multisine signal according to a second example. [Figure 6] FIG. 10 is an explanatory diagram showing a divided multisine signal according to a third example. [Figure 7] 10 is a flowchart showing a method for calculating a frequency response. [Figure 8] FIG. 10 is an explanatory diagram showing a state in which a frequency response is calculated by a discrete Fourier transform of the arithmetic unit. [Figure 9] Fig. 9(A) is an explanatory diagram showing an example of performing a discrete Fourier transform on a time-series waveform, and Fig. 9(B) is an explanatory diagram showing the relationship between the calculation formula of the discrete Fourier transform and the frequency response of each frequency. [Figure 10] FIG. 10 is a diagram showing the overall configuration of a calculation system according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals, and duplicate explanations may be omitted. Furthermore, in each drawing, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding of the invention.

[0035] <Configuration of refrigeration equipment> First, an air conditioner 1, which is a refrigeration device to which a calculation system 100 according to the present disclosure is applied, will be described with reference to Fig. 1. The air conditioner 1 is a device that conditions air in a room space using a vapor compression refrigeration cycle. The air conditioner 1 according to the embodiment includes a compressor 2, a heat source-side heat exchanger 3, an expansion mechanism 4, and a user-side heat exchanger 5, and performs cooling operation.

[0036] For example, the compressor 2, heat source side heat exchanger 3, and expansion mechanism 4 are provided inside the heat source side unit of the air conditioner 1. The heat source side unit is an outdoor unit that is placed outside the building in which the air conditioner 1 is installed. On the other hand, the user side heat exchanger 5 is provided inside the user side unit of the air conditioner 1. The user side unit is an indoor unit that is placed in the living space of the building in which the air conditioner 1 is installed. Note that the expansion mechanism 4 is not limited to being provided in the heat source side unit, and may also be provided in the user side unit.

[0037] The heat source side unit and the user side unit are connected to each other via a first pipe 6 and a second pipe 7. The compressor 2, the heat source side heat exchanger 3, the expansion mechanism 4, the user side heat exchanger 5, the first pipe 6, and the second pipe 7 are internally sealed, and form a refrigerant circuit 8 that can circulate a refrigerant.

[0038] A single-stage centrifugal compressor can be applied as the compressor 2. The compressor 2 draws in low-pressure refrigerant circulating through the second pipe 7, compresses this refrigerant to turn it into high-pressure refrigerant, and discharges it to the heat-source-side heat exchanger 3. For example, the compressor 2 has a casing (not shown), and includes within this casing a magnetic bearing 20, a rotating shaft 25, a compression unit 26, a motor 27, and the like.

[0039] The magnetic bearing 20 levitates the rotating shaft 25 and supports the rotating shaft 25 so that the rotating shaft 25 can rotate freely without contact. In other words, the magnetic bearing 20 supports a load in the radial direction of the rotating shaft 25. In addition to the magnetic bearing 20, the compressor 2 may also include a magnetic bearing that supports a load in the axial direction of the rotating shaft 25 (thrust direction).

[0040] Specifically, magnetic bearing 20 has a plurality of electromagnets arranged at intervals in the circumferential direction. When a current controlled by an inverter is supplied to the coil of each electromagnet, magnetic bearing 20 generates a magnetic field between each electromagnet and rotating shaft 25, magnetically levitating rotating shaft 25 and supporting it in a contactless manner. The inverter of magnetic bearing 20 is controlled by magnetic bearing control device 10 connected to magnetic bearing 20.

[0041] The magnetic bearing control device 10 is a computer or microcontroller that has a control circuit board including a processor, memory, input / output interface, communication interface, etc. (not shown), and is dedicated to controlling only the magnetic bearing 20. The magnetic bearing control device 10 may also be installed alongside a control unit that controls the entire heat source unit of the air conditioning device 1.

[0042] The magnetic bearing 20 also includes a gap sensor 28 that detects the size of the gap (radial direction) between the rotating shaft 25 and each electromagnet. The type of gap sensor 28 is not particularly limited, but for example, a displacement sensor that can detect the radial position of the rotating shaft 25 can be applied. The magnetic bearing control device 10 controls the radial position of the rotating shaft 25 by controlling the power supplied to the coil of each electromagnet based on information about the actual position (radial gap size) of the rotating shaft 25 detected by the gap sensor 28.

[0043] The compression section 26 of the compressor 2 compresses the refrigerant drawn in from the second pipe 7, and is disposed in the compression space of the casing. The compression section 26 is mainly composed of an impeller provided at one axial end of the rotary shaft 25. The impeller rotates based on the rotational drive of the motor 27, thereby drawing in and compressing the refrigerant in the second pipe 7 to a high pressure, and discharging the refrigerant toward the user-side heat exchanger 5.

[0044] Furthermore, the motor 27 of the compressor 2 is provided at the other axial end of the rotary shaft 25 opposite the impeller. The motor 27 has a rotor and a stator (not shown) that rotate the rotary shaft 25, and its rotation is controlled by a control unit (not shown) of the air conditioning apparatus 1. Note that the mechanisms and arrangements of the magnetic bearing 20, thrust bearing, motor 27, etc. of the compressor 2 are not limited to those described above and various other configurations are possible. For example, the compressor 2 may have the magnetic bearing of the thrust shaft located at the other axial end opposite the impeller, while the motor 27 is located on the impeller side.

[0045] The compressor 2 can smoothly rotate the impeller by supporting the rotary shaft 25 in a non-contact manner by the magnetic bearing 20. This allows the compressor 2 to stably circulate the refrigerant through the refrigerant circuit 8 while compressing the refrigerant.

[0046] On the other hand, the heat source side heat exchanger 3 of the heat source side unit receives the compressed refrigerant and exchanges heat between the refrigerant and air or water, thereby dissipating the heat of the refrigerant. The expansion mechanism 4 is a mechanism for decompressing the refrigerant, and for example, an expansion valve can be used.

[0047] The refrigerant expanded (decompressed) by the expansion mechanism 4 flows into the user-side heat exchanger 5 of the user-side unit through the first pipe 6, and heat is exchanged between the refrigerant and the air in the living space, heating the refrigerant. The user-side unit can lower the temperature of the air discharged from the user-side unit by cooling the air as a result of the heat exchange in the user-side heat exchanger 5.

[0048] The air conditioner 1 may be configured to reverse the flow direction of the refrigerant by installing a switching valve (a three-way or four-way switching valve, not shown) between the compressor 2 and the heat source-side heat exchanger 3. This switching of the refrigerant flow enables the air conditioner 1 to perform heating operation in addition to cooling operation.

[0049] When installing or maintaining the air conditioning apparatus 1, the frequency response of one or both of the controlled object and the control device may be measured at the site where the apparatus is installed. This frequency response is a transfer function that includes the characteristics of the amplitude ratio and phase difference between the input signal and output signal of selected components of the controlled object and the control device. For example, to properly control the levitation state of the rotating shaft 25, it is necessary to properly measure and recognize the transfer function of the magnetic bearing 20 of the compressor 2. Hereinafter, the task of measuring the frequency response at the site of use will also be referred to as a field test.

[0050] <Calculation system> When conducting a field test of the magnetic bearing 20, an operator constructs, for example, a calculation system 100 as shown in Figures 1 and 2. The calculation system 100 is formed by applying a computing device 50 to a magnetic bearing system consisting of a magnetic bearing control device 10 and a magnetic bearing 20 that are installed at the site of use in conjunction with the installation of the air conditioning device 1. The computing device 50 acquires input signals and output signals from selected locations in the magnetic bearing control device 10, which is the control device, and the magnetic bearing 20, which is the controlled object, and calculates the frequency response of that location.

[0051] The arithmetic device 50 may be a computer having a processor 51, a memory 52, and an input / output interface and a communication interface (not shown). The processor 51 may be one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit made up of multiple discrete semiconductors, etc. The memory 52 includes a main memory device and an auxiliary memory device. In other words, in this disclosure, the arithmetic device 50 is an electronic circuit having a CPU, a GPU, an ASIC, an FPGA, etc., which executes various control operations described in this specification by executing instruction codes stored in the memory 52 or by being a circuit designed for a specific application. The processor 51 of the arithmetic device 50 executes a program stored in the memory 52 to implement a signal acquisition unit 511 and a calculation unit 512, as shown in FIG. 2, for example.

[0052] The signal acquisition unit 511 acquires data on input signals and output signals from the components of the magnetic bearing control device 10 and the magnetic bearing 20 selected by the operator, and temporarily stores the data in the memory 52. ​​The arithmetic device 50 may automatically delete the data on input signals and output signals stored in the memory 52 after calculating the frequency response. This allows the arithmetic device 50 to appropriately ensure the capacity of the memory 52 in the process of calculating the frequency responses of multiple frequencies.

[0053] The calculation unit 512 is a functional unit that calculates a frequency response based on the input signal and the output signal acquired by the signal acquisition unit 511. The calculation of the frequency response by the calculation unit 512 will be described in detail later.

[0054] On the other hand, the magnetic bearing control device 10 and the magnetic bearing 20 control the levitation of the rotating shaft 25 of the compressor 2 using various configurations as shown in Fig. 2. Specifically, the magnetic bearing control device 10 includes a levitation position command unit 11, a subtractor 12, a position control unit 13, a supporting force-to-current conversion unit 14, and a current control unit 15. Each unit of the magnetic bearing control device 10 is a software functional unit formed by the processor of the magnetic bearing control device 10 executing a program stored in memory. However, without being limited to this, each unit of the magnetic bearing control device 10 may also be a hardware functional unit formed by an appropriate circuit.

[0055] The levitation position command unit 11 calculates a position command value x of the rotation shaft 25 based on the target position of the rotation shaft 25 received from the control unit of the heat source side unit. * is output to the subtractor 12. For example, the target position of the rotary shaft 25 is determined or calculated in the control unit to be an appropriate position depending on the model of the compressor 2 and the driving details.

[0056] The subtractor 12 subtracts the position command value x output from the levitation position command unit 11. * and the actual position x fed back from the gap sensor 28 of the magnetic bearing 20. The subtractor 12 subtracts the position command value x * is subtracted from the actual position x, and the corrected position deviation xEr is output to the position control unit 13.

[0057] When the position deviation xEr is input, the position control unit 13 determines a supporting force command value f for levitating the rotating shaft 25 by the magnetic bearing 20 based on the position deviation xEr and placing it at an appropriate position. * Then, the position control unit 13 calculates the calculated supporting force command value f * is output to the supporting force-current converter 14.

[0058] The supporting force-current conversion unit 14 converts the supporting force command value f * When input, the supporting force command value f * The current command value i supplied to the magnetic bearing 20 based on * and outputs it to the current control unit 15. For example, the supporting force-current conversion unit 14 calculates the supporting force command value f* and the current command value i * The supporting force command value f * to the current command value i * Extract.

[0059] The current control unit 15 determines the current command value i * When this current command value i * For example, the current control unit 15 outputs a control signal for the inverter 21 of the magnetic bearing 20 according to the voltage command value v * Calculate the voltage command value v * Output.

[0060] The magnetic bearing 20 of the compressor 2, which is the object to be controlled, includes an inverter 21, a coil 22, an electromagnet 23, a magnetic bearing rotor 24, and a gap sensor 28. Each component of the magnetic bearing 20 is a hardware functional unit formed by appropriate members.

[0061] The inverter 21 outputs a voltage command value v * When the voltage command value v * The magnetic bearing 20 outputs an actual voltage v corresponding to the frequency of the magnetic bearing 20 to the coil 22. The actual voltage v corresponding to the frequency of the magnetic bearing 20 is input to the coil 22, and the magnetic bearing 20 is subjected to voltage control via the inverter 21.

[0062] Coil 22 is supplied with power of actual voltage v output from inverter 21. This allows coil 22 to pass a controlled actual current i through electromagnets 23. Each electromagnet 23 is excited based on the actual current i of coil 22, generating an actual supporting force f that levitates rotating shaft 25. The levitated position of rotating shaft 25 is adjusted based on the actual supporting force f (magnetic field) of each electromagnet 23 that orbits around the rotating shaft 25.

[0063] The gap sensor 28 detects the gap dimension of the rotating shaft 25 relative to the magnetic bearing 20 when the rotating shaft 25 is levitated, and transmits the detected information (the actual position x of the rotating shaft 25) to the magnetic bearing control device 10. The magnetic bearing control device 10 feeds back the actual position of the rotating shaft 25 to the subtractor 12. The subtractor 12 calculates the position command value x of the rotating shaft 25 as described above. * The position of the rotation axis 25 is corrected by subtracting the actual position x from

[0064] The operator then constructs the calculation system 100 by connecting the arithmetic unit 50 to a location in each of the magnetic bearing control device 10 and the magnetic bearing 20 where a frequency response is desired to be obtained. The calculation system 100 outputs an excitation signal, the frequency of which is set and controlled, from the magnetic bearing control device 10 to the magnetic bearing 20, while acquiring, by the arithmetic unit 50, an input signal input to a selected location in the control loop to which the excitation signal is input, and an output signal output from the selected location in the control loop to which the excitation signal is input. The excitation signal may be supplied from outside the control loop as shown in FIG. 10, but the input and output signals for calculating the frequency response are acquired from within the control loop. In other words, the "input signal" is a signal input to a location in the control loop of the magnetic bearing control device 10 and the magnetic bearing 20 where a frequency response is desired to be obtained. This input signal may be the excitation signal initially input from the signal generating unit 30, or may be a signal (command value, actual voltage, actual current, actual position) input to each component of the magnetic bearing control device 10 and the magnetic bearing 20. Furthermore, the "output signal" is a signal output from a point in the control loop of the magnetic bearing control device 10 and the magnetic bearing 20 where a frequency response is desired to be obtained. By acquiring and calculating these input and output signals, the calculation device 50 can calculate the frequency response of the selected point.

[0065] The part of each component of the magnetic bearing control device 10 and the magnetic bearing 20 selected by the operator may be the whole or a part of each component of the magnetic bearing control device 10 and the magnetic bearing 20. For example, when measuring the whole of the magnetic bearing control device 10 and the magnetic bearing 20, the position command value x* (input signal) and the actual position x (output signal) of the gap sensor 28 of the magnetic bearing 20. For example, when measuring the frequency response of the current control system of the magnetic bearing control device 10 and the magnetic bearing 20, the current command value i * , and calculates the frequency response between the actual current i as the output signal. Alternatively, the calculation system 100 may calculate the frequency response only within the magnetic bearing control device 10. As an example, when checking the frequency response of the position control unit 13, the position deviation xEr (input signal) input to the position control unit 13 and the supporting force command value f * Calculate the frequency response of (the output signal).

[0066] The calculation system 100 described above includes a signal generating unit 30 and a user setting unit 31 that allows the user to set the state of the excitation signal in order to output an excitation signal from the magnetic bearing control device 10 to the magnetic bearing 20 in measuring the frequency response. Fig. 2 illustrates an example in which the signal generating unit 30 and the user setting unit 31 are pre-installed inside the magnetic bearing control device 10.

[0067] The user setting unit 31, for example, works in conjunction with the operation unit and display unit of the magnetic bearing control device 10 to allow an operator to set the state of the excitation signal that the operator wishes to recognize. The state of the excitation signal that the operator sets may include the frequency band, the number of frequencies (frequency resolution for calculating the frequency response), amplitude, etc. The user setting unit 31 may be configured to allow the operator to set all or only some of the states of the excitation signal.

[0068] The signal generating unit 30 generates an excitation signal based on the settings of the user setting unit 31, and outputs the excitation signal to the levitation position command unit 11 of the magnetic bearing control device 10. The "excitation signal" is a signal that has a frequency that changes to check the operation of the magnetic bearing 20, and is output from the signal generating unit 30 and applied to the magnetic bearing 20 that is the object of control, causing the magnetic bearing 20 to vibrate. The signal generating unit 30 according to the embodiment generates, as the excitation signal, a divided multi-sine signal having, on different time axes, a first waveform obtained by superimposing a plurality of sine waves with different frequencies, and a second waveform obtained by superimposing a plurality of sine waves with different frequencies and which is a waveform different from the first waveform.

[0069] <Split multi-sine signal> The significance of using this divided multi-sine signal and the types of divided multi-sine signals will be explained below with reference to Figs. 3 to 6. When measuring the frequency response of a control device and a controlled object, excitation signals of multiple frequencies are usually generated and output in sequence, and the frequency response for each of the multiple frequencies is measured. For example, the frequency response for each frequency is calculated while increasing the frequency from low to high within the frequency band of the excitation signal. In this case, the frequency of the excitation signal changes at appropriate intervals. In particular, measuring the frequency response for a large number of frequencies (for example, hundreds to thousands of frequencies) takes a significant amount of time.

[0070] For this reason, a known method for calculating frequency responses is to generate a multi-sine signal by superimposing multiple sine waves with different frequencies, output the signal as an excitation signal, and simultaneously calculate the frequency responses of the multiple frequencies contained in the multi-sine signal, as shown in Figure 3. For ease of understanding, Figure 3 illustrates a multi-sine signal by adding together six sine waves with different frequencies. When calculating the frequency response, the superimposed sine waves of the multiple frequencies contained in the multi-sine signal can be decomposed into separate sine waves, and the frequency response of each sine wave can be calculated.

[0071] However, the larger the frequency band to be measured or the number of superimposed sine waves, the greater the load on the processing load and memory capacity of the arithmetic device. In field tests at the site where the air conditioning device 1 described above is installed, it may be difficult to use a high-performance arithmetic device for analysis, as it may be difficult to bring in or it may take time to arrange and transport. Furthermore, field tests often require limited time because inspections and maintenance of other parts of the air conditioning device 1 are also performed. Therefore, the calculation system 100 according to the embodiment generates a divided multi-sine signal in which the sine waves contained in the excitation signal are changed on the time axis of the excitation signal, depending on the performance of the arithmetic device 50.

[0072] The divided multi-sine signal generated by the signal generating unit 30 may be, for example, the first example shown in Fig. 4. The divided multi-sine signal of the first example has a pattern in which multiple sine waves included in the divided multi-sine signal are switched at the same timing. That is, the divided multi-sine signal of the first example changes all of the sine waves to be superimposed at each set time point simultaneously, thereby making the waveform different for each set range on the time axis.

[0073] 4, the divided multi-sine signal has a first waveform in the period from time t1 to time t2, a second waveform in the period from time t2 to time t3, and a third waveform in the period from time t3 to time t4. The first waveform is formed by superimposing a sine wave of frequency f11, a sine wave of frequency f12, a sine wave of frequency f13, ..., a sine wave of frequency f1n. Similarly, the second waveform is formed by superimposing a sine wave of frequency f21, a sine wave of frequency f22, a sine wave of frequency f23, ..., a sine wave of frequency f2n. The third waveform is formed by superimposing a sine wave of frequency f31, a sine wave of frequency f32, a sine wave of frequency f33, ..., a sine wave of frequency f3n.

[0074] In this case, the periods of the first waveform, second waveform, third waveform, ..., nth waveform may be the same length or different lengths. By making the periods the same length, the signal generating unit 30 can easily manage each waveform and the sine waves contained in the waveforms. On the other hand, if the periods are different lengths, the signal generating unit 30 can shorten the periods, for example, as the magnitude of the frequency contained in each waveform increases. In other words, the periods of the first waveform, second waveform, third waveform, ..., nth waveform may be set according to the sine wave with the smallest frequency among the sine waves contained in each waveform. This allows the overall period of the field test to be shortened.

[0075] When generating a divided multi-sine signal, it is preferable to generate each waveform (first waveform, second waveform, third waveform, ... nth waveform) by superimposing sine waves of similar frequencies. For example, when the frequency band to be measured is 1 Hz to 10 Hz and there are 10 frequencies (in 1 Hz increments), when forming divided multi-sine signals of the first waveform and the second waveform, a first waveform is generated by superimposing a total of five sine waves of 1 Hz to 5 Hz, and a second waveform is generated by superimposing a total of five sine waves of 6 Hz to 10 Hz.

[0076] To calculate the frequency response for each sine wave of multiple frequencies, at least one waveform cycle is required for each sine wave. The lower the frequency of the sine wave, the longer the cycle. For example, if a 10 Hz sine wave and a 1 Hz sine wave are combined, the 10 Hz sine wave will repeat multiple times until the 1 Hz sine wave cycle is completed, which takes a long time. However, by overlapping sine waves of similar frequencies, it is possible to shorten the duration of each waveform in the divided multi-sine signal.

[0077] Furthermore, sine wave 1, sine wave 2, sine wave 3, ..., sine wave n in FIG. 4 are set to have different amplitudes, but the first and second waveforms, which have different time axes, may have the same amplitude. For example, the sine wave with frequency f11, the sine wave with frequency f21, the sine wave with frequency f31, ..., and the sine wave with frequency fn1 that are lined up in sine wave 1 may have the same amplitude. The same applies to sine wave 2, sine wave 3, ..., and sine wave n. However, this is not a limitation, and for example, the sine wave with frequency f11, the sine wave with frequency f21, the sine wave with frequency f31, ..., and the sine wave with frequency fn1 that are lined up in sine wave 1 may have different amplitudes for some or all of them. The same applies to sine wave 2, sine wave 3, ..., and sine wave n.

[0078] Furthermore, it is preferable that the amplitude of each sine wave forming each waveform be set to a larger value as the frequency of the sine wave increases. This is because the higher the frequency, the greater the inertial force of the magnetic bearing 20, and the smaller the ratio (gain) of the output signal to the excitation signal. For example, if the frequency relationship of each sine wave in the first waveform is frequency f11 > frequency f12 > frequency f13 > ... frequency f1n, then the amplitudes should also be set to frequency f11 > frequency f12 > frequency f13 > ... frequency f1n.

[0079] 5 as the divided multi-sine signal to be generated. The divided multi-sine signal of the second example has a pattern in which the multiple sine waves included in the divided multi-sine signal are switched at different timings. That is, the divided multi-sine signal of the second example switches between sine waves of one (or multiple) frequencies while maintaining sine waves of the other frequencies, thereby switching in order from a first waveform to a second waveform, a third waveform, ..., and an n-th waveform.

[0080] In FIG. 5, the divided multi-sine signal is formed by superimposing a sine wave of frequency f11, a sine wave of frequency f12, a sine wave of frequency f13, ..., and a sine wave of frequency f1n in the first waveform from time t1 to time t2. Then, at the transition at time t2, only the sine wave of frequency f11 switches to a sine wave of frequency f12, while the sine waves of the other frequencies do not switch. In other words, the second waveform from time t2 to time t3 is formed by superimposing a sine wave of frequency f21, a sine wave of frequency f12, a sine wave of frequency f13, ..., and a sine wave of frequency f1n. Similarly, at the transition at time t3, only the sine wave of frequency f12 switches to a sine wave of frequency f22, while the sine waves of the other frequencies do not switch. That is, the third waveform from time t3 to time t4 is formed by superimposing a sine wave of frequency f21, a sine wave of frequency f22, a sine wave of frequency f13, ..., a sine wave of frequency f1n. Similarly, at each transition of the individual sine waves thereafter, the waveform of the divided multi-sine signal changes to a different form.

[0081] In the second example, the divided multi-sine signal is not limited to switching between sine waves of one frequency at the same time, but may switch between sine waves of multiple frequencies simultaneously. For example, Fig. 5 illustrates an example in which a sine wave of frequency f21 and a sine wave of frequency f1n are simultaneously switched to a sine wave of frequency f31 and a sine wave of frequency f2n at time t5.

[0082] The timing of switching between each sine wave (in other words, the period during which a sine wave of each frequency is output) can be determined according to the frequency of each sine wave. For example, the switching timing can be set earlier for sine waves with higher frequencies. This is because a sine wave with higher frequencies repeats its amplitude more times (periods) within a set period.

[0083] 5 are set to have different amplitudes, but the amplitudes of the sine waves that switch at each point in time may be the same or different. For example, in sine wave 1, the sine wave of frequency f11, the sine wave of frequency f21, the sine wave of frequency f31, ... the sine wave of frequency fn1 are set to the same amplitude, and sine wave 2, sine wave 3, ... sine wave n are also set to the same amplitude, thereby making it easier to manage each sine wave.

[0084] Furthermore, in the first example shown in Fig. 4 and the second example shown in Fig. 5, the signal generator 30 sets the number of sine waves forming each waveform of the divided multi-sine signal to be the same on the time axis. By setting the number of sine waves of each waveform to be the same in this way, it becomes possible to output the excitation signal efficiently and shorten the time required to calculate the frequency response.

[0085] However, this is not limiting, and as shown in the third example in FIG. 6, the divided multi-sine signal may have the frequency and amplitude of one or more of the multiple sine waves forming each waveform set to zero (a configuration in which no sine waves are output). For example, FIG. 6 shows a second example of the divided multi-sine signal in which some of the multiple sine waves are set to zero. As an example, the divided multi-sine signal in the second example switches waveforms in response to the switching of one sine wave. However, in some cases, it may be better to switch multiple sine waves simultaneously. One example of this is when resonance occurs due to a combination of frequencies. In such a case, the signal generating unit 30 can set some of the sine waves to zero so that the multiple sine waves are switched at the same timing at any point in time.

[0086] 6, some sine waves are set to zero in the divided multi-sine signal of the second example, but some sine waves may also be set to zero in the divided multi-sine signal of the first example. For example, in the early stage when the arithmetic device 50 calculates the frequency response, the waveform of the divided multi-sine signal may be formed using a large number of sine waves, while in the later stage when the arithmetic device 50 calculates the frequency response, each waveform of the divided multi-sine signal may be formed using a small number of sine waves. This is because in the later stage when the frequency response is calculated, there is a possibility that the processing capacity of the arithmetic device 50 may decrease due to an increase in cache memory, etc.

[0087] The signal generating unit 30 may automatically set the number and period of sine waves included in the waveform of the divided multi-sine signal, the number of divisions and period of each waveform, etc., based on the frequency band and number of frequencies (frequency resolution for calculating frequency response) set by the operator and the performance of the computing device 50. Examples of the performance of the computing device 50 include the number of calculation processes per unit time of the processor 51, the capacity of the memory 52 for storing input signals and output signals, etc.

[0088] For example, when the number of calculation processes per unit time of the processor 51 is large, the number of sine waves included in the waveform of the divided multi-sine signal is increased, thereby setting the number of divisions of each waveform of the divided multi-sine signal to be small. Conversely, when the number of calculation processes per unit time of the processor 51 is small, the number of sine waves included in the waveform of the divided multi-sine signal is decreased, thereby setting the number of divisions of each waveform of the divided multi-sine signal to be large. Alternatively, when the capacity of the memory 52 is large, the number of sine waves included in the waveform of the divided multi-sine signal is increased, thereby setting the number of divisions of each waveform of the divided multi-sine signal to be small. Conversely, when the capacity of the memory 52 is small, the number of sine waves included in the waveform of the divided multi-sine signal is decreased, thereby setting the number of divisions of each waveform of the divided multi-sine signal to be large.

[0089] However, the actual performance of the arithmetic device 50 is a combination of the number of calculations per unit time of the processor 51 and the capacity of the memory 52. ​​Therefore, the signal generating unit 30 may combine these pieces of information to set the number of sine waves included in each waveform of the divided multi-sine signal. Of course, since the performance of the arithmetic device 50 also varies depending on other factors (thermal control, communication speed, etc.), each waveform of the divided multi-sine signal may be generated based on various factors.

[0090] <Calculation method> The air conditioning apparatus 1 and calculation system 100 according to the embodiment are basically configured as described above, and their operation will be described below with reference to the flowchart in Fig. 7. The magnetic bearing control device 10 and the arithmetic device 50 of the calculation system 100 cooperate with each other to execute steps S101 to S107 in Fig. 7 as a method for calculating the frequency response.

[0091] In the calculation method, an operator first selects the locations in the magnetic bearing control device 10 and the magnetic bearing 20 where frequency responses are to be calculated, in other words, the locations of the input signals and output signals to be acquired by the arithmetic device 50 (step S101). As described above, the calculation system 100 can selectively acquire frequency responses for some or all of the components of the magnetic bearing control device 10, which is the control device, and the magnetic bearing 20, which is the controlled object.

[0092] Next, in the calculation method, the operator sets the frequency band and the number of frequencies (resolution) within which the frequency response is calculated via the user setting unit 31 (step S102). For example, the frequency band of the magnetic bearing 20 may be in the range of 1 Hz to 2000 Hz. Furthermore, the frequency resolution of the magnetic bearing 20 may be in 1 Hz units (for a range of 1 Hz to 2000 Hz, the number of frequencies is 2000).

[0093] Then, the signal generating unit 30 sets the number of sine waves included in each waveform of the divided multi-sine signal and the number of divisions of each waveform based on the set frequency bands and the number of frequencies and the performance of the arithmetic unit 50 (step S103). As described above, if the performance of the arithmetic unit 50 is high, it is preferable to set the number of sine waves included in each waveform of the divided multi-sine signal to be large. On the other hand, if the performance of the arithmetic unit 50 is low, it is preferable to set the number of sine waves included in each waveform of the divided multi-sine signal to be small.

[0094] When step S103 is completed, the calculation system 100 proceeds to the stage of actually acquiring the frequency response in a field test. In this case, the signal generating unit 30 generates each waveform of the divided multi-sine signal along the time axis according to the settings of the above steps, and outputs the divided multi-sine signal to the magnetic bearing 20, which is the control target, via the magnetic bearing control device 10 (step S104).

[0095] The signal acquisition unit 511 of the calculation device 50 acquires the input signals and output signals when each waveform of the divided multi-sine signal is input at a location selected by the operator among the components of the magnetic bearing control device 10 and the magnetic bearing 20 (step S105).

[0096] The calculation unit 512 of the arithmetic device 50 then calculates a frequency response by discrete Fourier transform while acquiring the input signal and the output signal using the signal acquisition unit 511 (step S106). Specifically, the calculation unit 512 acquires an input signal as shown in the upper left diagram of FIG. 8 and an output signal as shown in the upper right diagram of FIG. 8. The calculation unit 512 performs DFT processing, which is a discrete Fourier transform (fast Fourier transform), on these input and output signals (hereinafter also referred to as input and output signals), and calculates the frequency response for each sine wave included in the waveform. The frequency response for each of multiple sine waves (1 Hz, 2 Hz, ...) is calculated, including the characteristics of the amplitude ratio and phase difference of the input and output signals for each frequency, as shown in (1), (2), and (3) in the lower diagram of FIG. 8.

[0097] Specifically, the calculation unit 512 performs the calculations shown in Fig. 9(A) and Fig. 9(B) in the DFT processing. In the DFT processing, as shown in Fig. 9(A), for N sections in each waveform (time-series waveform) of the divided multi-sine signal, a discrete signal x(n) (x(0), x(1), x(2), ... x(N-1)) is added up at each time using the following formula (1) of the discrete Fourier transform.

[0098]

number

[0099] The calculation unit 512 can calculate the frequency response X(0), X(1), X(2), ..., X(N-1) for each sine wave included in each waveform by adding together N values ​​calculated using Equation (1) using the discrete signals x(0), x(1), x(2), ..., x(N-1), as shown in FIG. 9(B). In this case, the frequency responses X(0), X(1), X(2), ..., X(N-1) for each sine wave are independent and do not affect each other. Therefore, the calculation unit 512 can calculate the frequency responses X(0), X(1), X(2), ..., X(N-1) in parallel. The frequency responses X(0), X(1), X(2), ..., X(N-1) for each sine wave include amplitude ratio and phase difference characteristics, as shown in the left diagram of FIG. 9(B). In this way, the calculation section 512 can accurately calculate the frequency response for each of a plurality of sine waves with different frequencies.

[0100] For example, the calculation unit 512 calculates the frequency response (amplitude ratio or phase difference) for each of the multiple sine waves forming the first waveform by adding up values ​​calculated using Equation (1) using discrete signals calculated for each arbitrary time of the first waveform. After the calculation of the first waveform is completed, the calculation unit 512 deletes the discrete signals used for the calculation. Then, for example, the calculation unit 512 calculates the frequency response (amplitude ratio or phase difference) for each of the multiple sine waves forming the second waveform by adding up values ​​calculated using Equation (1) using discrete signals calculated for each arbitrary time of the second waveform. The calculation unit 512 repeats this calculation for each waveform of the divided multi-sine signal to obtain the frequency responses of the multiple sine waves included in all waveforms.

[0101] 7, in step S107 after step S106, the arithmetic device 50 determines whether or not the frequency responses have been measured for all waveforms (sine waves of all frequencies) of the divided multi-sine signal. If the frequency responses of some of the waveforms of the divided multi-sine signal have not been measured (step S107: NO), the arithmetic device 50 returns to step S104 and repeats the same processing flow thereafter. On the other hand, if the frequency responses of all waveforms of the divided multi-sine signal have been measured (step S107: YES), the processing flow of the calculation method ends.

[0102] As described above, the arithmetic device 50 can accurately calculate the frequency response of selected locations in each configuration of the magnetic bearing control device 10 and the magnetic bearing 20 for each of a plurality of frequencies. By knowing this frequency response, an operator can grasp the stability of signal transmission according to frequency, or delays in signal transmission, abnormalities, etc., in the magnetic bearing control device 10 and the magnetic bearing 20. For example, an operator can use the grasped frequency response to identify maintenance targets for the magnetic bearing control device 10 and the magnetic bearing 20 based on the frequency response. Furthermore, in controlling the magnetic bearing 20, the magnetic bearing system can accurately adjust the state of power supplied to the magnetic bearing 20, etc., according to the frequency response, by automatically or manually correcting the software of the magnetic bearing control device 10.

[0103] The calculation system 100 and the refrigeration device 1 according to the present disclosure are not limited to the above embodiment and may take various modified forms. For example, in the above embodiment, the frequency response is calculated by the arithmetic device 50, which is a computer separate from the magnetic bearing control device 10. However, the calculation system 100 may be configured to include only the magnetic bearing control device 10 and the magnetic bearing 20 by incorporating the functions of the arithmetic device 50 (signal acquisition unit 511, calculation unit 512) within the magnetic bearing control device 10. Furthermore, the calculation system 100 is not limited to being applied to the refrigeration device 1 or magnetic bearing system, but may also be applied to various devices that require frequency response calculation. Furthermore, the calculation system 100 is not limited to being configured to calculate the frequency response of devices installed at the site of use, but may also be applied to devices in locations where devices are developed, manufactured, etc., such as laboratories, test sites, and factories.

[0104] 10, the signal generating unit 30 and the user setting unit 31 do not necessarily have to be provided inside the magnetic bearing control device 10, but may be provided outside the magnetic bearing control device 10. For example, FIG. 10 shows an example in which an oscillator 32 having the signal generating unit 30 and the user setting unit 31 is connected to the magnetic bearing control device 10 and a divided multi-sine signal is output from the oscillator 32. This simplifies the configuration of the magnetic bearing control device 10, making it possible to reduce the size and cost of the device. Alternatively, the calculation system 100 may be configured such that the signal generating unit 30 and the user setting unit 31 are provided in a calculation device 50, and the calculation device 50 is connected to the magnetic bearing control device 10, thereby performing both the output of the excitation signal and the calculation of the frequency response.

[0105] <Aspects and Effects of the Present Disclosure> The above-disclosed embodiment has, for example, the following aspects and effects.

[0106] [Appendix 1] a signal generating unit that inputs a vibration signal from the control device to the controlled object to vibrate the controlled object; a calculation unit that calculates a frequency response of the control device and a part or all of the control object when the excitation signal is input to the control object, The excitation signal is a split multi-sine signal having a first waveform in which a plurality of sine waves with different frequencies are superimposed, and a second waveform in which a plurality of sine waves with different frequencies are superimposed and which is a waveform different from the first waveform, on different time axes. Calculation system.

[0107] [Effects of Appendix 1] According to the above, the calculation system uses a divided multi-sine signal as an excitation signal when calculating the frequency response, and can input multiple waveforms having an appropriate number of sine waves to the control target by shifting them on the time axis depending on the performance of the calculation device. This makes it possible to efficiently obtain the frequency response of the control device and the control target depending on the performance of the calculation device. For example, the calculation system can obtain good frequency characteristics of the control target even in a site where the control target is used and where it is difficult to apply a high-performance calculation device.

[0108] [Appendix 2] the signal generating unit switches between all of the plurality of sine waves forming the first waveform and all of the plurality of sine waves forming the second waveform at the same timing; Calculation system according to appendix 1.

[0109] [Effects of Appendix 2] In this way, by switching between all of the multiple sine waves of the first waveform and all of the multiple sine waves of the second waveform at the same time, the calculation system can easily manage the multiple sine waves for which frequency responses are calculated.

[0110] [Appendix 3] the signal generating unit switches from the first waveform to the second waveform by switching some of the plurality of sine waves forming the first waveform to sine waves having different frequencies. Calculation system according to appendix 1.

[0111] [Effects of Appendix 3] In this way, by switching some of the sine waves that form the first waveform to sine waves with different frequencies, the calculation system can more efficiently calculate the frequency responses of all the sine waves.

[0112] [Appendix 4] The number of the plurality of sine waves forming the first waveform is the same as the number of the plurality of sine waves forming the second waveform. 4. A calculation system according to any one of claims 1 to 3.

[0113] [Effects of Appendix 4] In this way, by having the same number of sinusoidal waves forming the first waveform as the same number of sinusoidal waves forming the second waveform, the calculation system can more efficiently calculate the frequency response of the sinusoidal waves.

[0114] [Appendix 5] the signal generation unit sets a larger amplitude for a sine wave having a higher frequency among the plurality of sine waves of the divided multi-sine signal; 5. A calculation system according to any one of claims 1 to 4.

[0115] [Effects of Appendix 5] This allows the calculation system to calculate the frequency response well even for sine waves with high frequencies.

[0116] [Appendix 6] the frequency response includes characteristics of an amplitude ratio and a phase difference between an input signal and an output signal; the calculation unit calculates the amplitude ratio or the phase difference for each of a plurality of sine waves by performing a discrete Fourier transform on the input signal and the output signal acquired from the control device or the controlled object. 6. A calculation system according to any one of claims 1 to 5.

[0117] [Effects of Appendix 6] In this way, by performing a discrete Fourier transform, the calculation system can easily calculate the frequency response for each sine wave of multiple frequencies.

[0118] [Appendix 7] The calculation unit calculating the amplitude ratio or the phase difference for each of a plurality of sine waves forming the first waveform by adding up values ​​calculated for each arbitrary time of the first waveform; and calculating the amplitude ratio or the phase difference for each of a plurality of sine waves forming the second waveform by adding up values ​​calculated for each arbitrary time of the second waveform. Calculation system according to appendix 6.

[0119] [Effects of Appendix 7] In this way, in the discrete Fourier transform, the amplitude ratio or phase difference of the frequency responses can be calculated independently by adding up the values ​​calculated at any time for the first and second waveforms. As a result, used data can be immediately deleted, and an increase in the memory capacity of the calculation device can be suppressed.

[0120] [Appendix 8] The signal generating unit is provided inside the control device. 8. A calculation system according to any one of claims 1 to 7.

[0121] [Effects of Appendix 8] By providing the signal generating unit inside the control device in this way, the time and effort required to prepare a separate signal generating unit is eliminated, and the frequency response can be obtained more easily.

[0122] [Appendix 9] The signal generating unit is provided outside the control device. 8. A calculation system according to any one of claims 1 to 7.

[0123] [Effects of Appendix 9] By providing the signal generating unit outside the control device in this way, it is possible to prevent the control device from becoming larger in size.

[0124] [Appendix 10] a user setting unit that allows a user to set a frequency band or a number of frequencies of the excitation signal to be input to the controlled object; the signal generation unit automatically sets the number of the plurality of sine waves included in the first waveform and the second waveform of the divided multi-sine signal based on the frequency band or the number of the frequencies set by the user setting unit. 10. A calculation system according to any one of claims 1 to 9.

[0125] [Effects of Appendix 10] This allows the calculation system to reduce the load set by the user when acquiring the frequency response, and also makes it possible to appropriately generate divided multi-sine signals.

[0126] [Appendix 11] A calculation system according to any one of Supplementary Notes 1 to 3; a magnetic bearing that supports the rotating shaft in a non-contact manner; a magnetic bearing control device for controlling the magnetic bearing, the controlled object is a magnetic bearing, The control device is a magnetic bearing control device. Magnetic bearing system.

[0127] [Effects of Appendix 11] This allows the calculation system to stably measure the frequency response of the magnetic bearing system.

[0128] [Appendix 12] a compressor having a magnetic bearing as a control target; a control device for controlling the operation of the magnetic bearing; a refrigeration apparatus including: a refrigerant circuit in which the compressor is provided and which circulates a refrigerant based on operation of the compressor; the control device inputs an excitation signal to the magnetic bearing for vibrating the magnetic bearing, and causes a calculation unit to calculate a frequency response of the magnetic bearing and a part or all of the control device when the excitation signal is input to the magnetic bearing; The excitation signal is a split multi-sine signal having a first waveform in which a plurality of sine waves with different frequencies are superimposed, and a second waveform in which a plurality of sine waves with different frequencies are superimposed and which is a waveform different from the first waveform, on different time axes. Refrigeration equipment.

[0129] [Effects of Appendix 12] Even in this case, the refrigeration system can obtain good frequency characteristics of the magnetic bearing even at the site where the compressor is used.

[0130] The refrigeration apparatus (air conditioner 1), calculation system 100, and magnetic bearing system according to the presently disclosed embodiments are illustrative in all respects and not restrictive. The embodiments may be modified and improved in various ways without departing from the spirit and scope of the appended claims. The matters described in the above embodiments may be configured differently within a consistent range, and may be combined within a consistent range. [Explanation of symbols]

[0131] 1. Refrigeration equipment (air conditioning equipment) 2 Compressor 8 Refrigerant circuit 10 Magnetic bearing control device 20 Magnetic bearings 25 Rotation axis 30 Signal generation unit 31 User Settings 50 Arithmetic unit 512 Calculation Unit

Claims

1. a signal generating unit (30) that inputs a vibration signal from the control device (10) to the controlled object (20) for vibrating the controlled object (20); a calculation unit (512) that calculates a frequency response of the control device (10) and a part or all of the control target (20) when the excitation signal is input to the control target (20), The excitation signal is a split multi-sine signal having a first waveform obtained by superimposing a plurality of sine waves having different frequencies and a second waveform obtained by superimposing a plurality of sine waves having different frequencies and being a waveform different from the first waveform, on different time axes. A computing system (100).

2. The signal generating unit (30) switches between all of the plurality of sine waves forming the first waveform and all of the plurality of sine waves forming the second waveform at the same timing. The computing system (100) of claim 1.

3. the signal generating unit (30) switches from the first waveform to the second waveform by switching some of the plurality of sine waves forming the first waveform to sine waves of different frequencies; The computing system (100) of claim 1.

4. The number of the plurality of sine waves forming the first waveform is the same as the number of the plurality of sine waves forming the second waveform. A computing system (100) according to any one of claims 1 to 3.

5. The signal generating unit (30) sets a larger amplitude for a sine wave having a higher frequency among the plurality of sine waves of the divided multi-sine signal. A computing system (100) according to any one of claims 1 to 3.

6. the frequency response includes characteristics of an amplitude ratio and a phase difference between an input signal and an output signal; The calculation unit (512) calculates the amplitude ratio or the phase difference for each of a plurality of sine waves by performing a discrete Fourier transform on the input signal and the output signal acquired from the control device (10) or the controlled object (20). A computing system (100) according to any one of claims 1 to 3.

7. The calculation unit (512) calculating the amplitude ratio or the phase difference for each of a plurality of sine waves forming the first waveform by adding up values ​​calculated for each arbitrary time of the first waveform; and calculating the amplitude ratio or the phase difference for each of a plurality of sine waves forming the second waveform by adding up values ​​calculated for each arbitrary time of the second waveform. The computing system (100) of claim 6.

8. The signal generating unit (30) is provided inside the control device (10). A computing system (100) according to any one of claims 1 to 3.

9. The signal generating unit (30) is provided outside the control device (10). A computing system (100) according to any one of claims 1 to 3.

10. a user setting unit (31) that allows a user to set a frequency band or a number of frequencies of the excitation signal to be input to the controlled object (20); The signal generating unit (30) automatically sets the number of sine waves included in the first waveform and the second waveform of the divided multi-sine signal based on the frequency band or the number of frequencies set by the user setting unit (31). A computing system (100) according to any one of claims 1 to 3.

11. A calculation system (100) according to any one of claims 1 to 3; a magnetic bearing (20) that supports a rotating shaft (25) in a non-contact manner; A magnetic bearing system comprising: a magnetic bearing control device (10) that controls the magnetic bearing (20), The controlled object (20) is a magnetic bearing, The control device (10) is a magnetic bearing control device. Magnetic bearing system.

12. a compressor (2) having a magnetic bearing (20) as a control target; a control device (10) for controlling the operation of the magnetic bearing (20); a refrigeration system (1) including the compressor (2) and a refrigerant circuit (8) that circulates a refrigerant based on operation of the compressor (2), The control device (10) inputs an excitation signal to the magnetic bearing (20) for vibrating the magnetic bearing (20), and causes a calculation unit (512) to calculate frequency responses of the magnetic bearing (20) and part or all of the control device (10) when the excitation signal is input to the magnetic bearing (20); The excitation signal is a split multi-sine signal having a first waveform obtained by superimposing a plurality of sine waves having different frequencies and a second waveform obtained by superimposing a plurality of sine waves having different frequencies and being a waveform different from the first waveform, on different time axes. Refrigeration device (1).

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