Control method of refrigeration equipment and refrigeration equipment

Abstract

The invention discloses a control method of refrigeration equipment and the refrigeration equipment, and belongs to the technical field of refrigeration equipment. The control method of the refrigeration equipment comprises the steps that under the condition that a compressor is in a running state, a controller calculates a target carrier frequency based on load information corresponding to the compressor and the actual environment temperature of the environment where the compressor is located; the controller performs modulation processing on the target carrier frequency to obtain a target frequency signal; and the controller controls the rotating speed of the compressor based on the target frequency signal. According to the control method of the refrigeration equipment, the switching loss can be minimized on the basis of ensuring the output precision, energy of a single frequency can be dispersed to a wider frequency band, the frequency spectrum is diffused, the interference peak value of a specific frequency point is reduced, electromagnetic interference and electromagnetic noise are reduced, and the use experience of a user is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of refrigeration equipment, and in particular relates to a control method for refrigeration equipment and refrigeration equipment. Background Art

[0002] Traditional compressor variable frequency drive technologies mostly use a fixed PWM (Pulse Width Modulation) carrier frequency, generally selecting a frequency within the range of 5kHz-8kHz. This method causes large switching losses when the variable frequency compressor is running under light load. At low load frequencies, due to the high carrier frequency, the high-frequency switching action of the power device will generate unnecessary losses. In addition, when the variable frequency compressor is running under heavy load, it will generate large electromagnetic interference (EMI) and electromagnetic noise, resulting in a poor user experience. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems existing in the related art. To this end, this application proposes a control method and refrigeration equipment that can minimize switching losses while ensuring output accuracy, disperse the energy of a single frequency across a wider frequency band, diffuse the spectrum, reduce interference peaks at specific frequency points, reduce electromagnetic interference and electromagnetic noise, and enhance the user experience.

[0004] In a first aspect, the present application provides a method for controlling a refrigeration device, wherein the refrigeration device includes a controller and a compressor connected thereto; the controller is configured to perform the following method:

[0005] When the compressor is in operation, the controller calculates a target carrier frequency based on load information corresponding to the compressor and an actual ambient temperature in an environment where the compressor is located;

[0006] The controller modulates the target carrier frequency to obtain a target frequency signal;

[0007] The controller controls the rotation speed of the compressor based on the target frequency signal.

[0008] According to the control method of the refrigeration equipment provided in the embodiment of the present application, by automatically identifying the load information of the compressor and dynamically adjusting the carrier frequency of the frequency conversion controller according to the load information, ambient temperature conditions and the operating load of the whole machine, the switching loss can be minimized while ensuring the output accuracy. By modulating the target carrier frequency to obtain the target frequency signal, the energy of a single frequency can be dispersed to a wider frequency band, so that the spectrum is diffused, the interference peak at a specific frequency point is reduced, the electromagnetic interference and electromagnetic noise are reduced, and the user experience is improved.

[0009] In a control method for a refrigeration device according to an embodiment of the present application, the target carrier frequency is modulated to obtain a target frequency signal, including:

[0010] Get the target jitter frequency;

[0011] The target jitter frequency is superimposed on the target carrier frequency to obtain the target frequency signal.

[0012] In a control method for a refrigeration device according to an embodiment of the present application, obtaining a target jitter frequency includes:

[0013] Determining a frequency jittering step size and a frequency jittering range based on the target carrier frequency and the load information;

[0014] Within the frequency jittering range, the target jittering frequency is calculated based on the frequency jittering step size.

[0015] In a control method for a refrigeration device according to an embodiment of the present application, obtaining a target jitter frequency includes:

[0016] Obtaining a maximum offset between the modulated signal and the target carrier frequency;

[0017] The target dithering frequency is determined based on the amplitude of the modulation signal and the maximum offset.

[0018] In a control method for a refrigeration device according to an embodiment of the present application, the target carrier frequency is calculated based on load information corresponding to the compressor and the actual ambient temperature of the environment in which the compressor is located, including:

[0019] Based on the load information and the actual ambient temperature, searching a preset relationship table for a candidate carrier frequency corresponding to the interval in which the load information is located and the interval in which the actual ambient temperature is located; the preset relationship table is used to represent a mapping relationship between the interval in which the load information is located, the interval in which the actual ambient temperature is located, and the candidate carrier frequency;

[0020] The candidate carrier frequency is determined as the target carrier frequency.

[0021] In a control method for a refrigeration device according to an embodiment of the present application, the target carrier frequency is calculated based on load information corresponding to the compressor and the actual ambient temperature of the environment in which the compressor is located, including:

[0022] When the load information and / or the actual ambient temperature is updated from the first interval to the second interval in the preset relationship table, obtaining difference information between the load information and / or the actual ambient temperature and a boundary threshold corresponding to the second interval; wherein, when it is determined that the load information and / or the actual ambient temperature has increased, the boundary threshold corresponding to the second interval is a lower boundary threshold of the second interval; and when it is determined that the load information and / or the actual ambient temperature has decreased, the boundary threshold corresponding to the second interval is an upper boundary threshold of the second interval;

[0023] If it is determined that the difference information is less than or equal to the target difference threshold, determining the candidate carrier frequency corresponding to the first interval as the target carrier frequency;

[0024] If it is determined that the difference information is greater than the target difference threshold, the candidate carrier frequency corresponding to the second interval is determined as the target carrier frequency.

[0025] In a second aspect, the present application provides a refrigeration device, comprising:

[0026] compressor;

[0027] A controller is connected to the compressor, and the controller is used to execute the control method of the refrigeration equipment as described in the first aspect.

[0028] According to the refrigeration equipment provided in the embodiment of the present application, by automatically identifying the load information of the compressor and dynamically adjusting the carrier frequency of the frequency conversion controller according to the load information, ambient temperature conditions and the operating load of the whole machine, the switching loss can be minimized while ensuring the output accuracy. By modulating the target carrier frequency to obtain the target frequency signal, the energy of a single frequency can be dispersed to a wider frequency band, so that the spectrum is diffused, the interference peak at a specific frequency point is reduced, the electromagnetic interference and electromagnetic noise are reduced, and the user experience is improved.

[0029] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the control method for the refrigeration equipment as described in the first aspect above is implemented.

[0030] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the control method for the refrigeration equipment as described in the first aspect above.

[0031] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the control method for the refrigeration equipment as described in the first aspect above.

[0032] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0033] By automatically identifying the load information of the compressor and dynamically adjusting the carrier frequency of the frequency converter according to the load information, ambient temperature conditions, and the operating load of the entire machine, the switching loss can be minimized while ensuring output accuracy. By modulating the target carrier frequency to obtain the target frequency signal, the energy of a single frequency can be dispersed over a wider frequency band, causing the spectrum to diffuse, reducing the interference peak at a specific frequency point, reducing electromagnetic interference and electromagnetic noise, and improving the user experience.

[0034] Furthermore, the frequency jittering step and frequency jittering range are generated through the target frequency signal and load information, so that the target jittering frequency is generated based on the frequency jittering step within the frequency jittering range, which can avoid the current loop control instability caused by excessive frequency offset. In addition, the target jittering frequency is adjusted in real time based on the load information, which can effectively avoid heat loss or oscillation caused by harmonics when the system is highly loaded.

[0035] Furthermore, by setting a difference threshold and a hysteresis mechanism, it is possible to determine whether the target carrier frequency needs to be adjusted based on whether the load information or the actual ambient temperature change is in the hysteresis interval, and to filter short-term fluctuations of the parameters at the interval boundary. This can avoid current harmonics and system oscillations caused by frequent switching of the carrier frequency. The load and temperature difference thresholds can be configured independently to adapt to a variety of different working conditions.

[0036] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0038] Figure 1 This is one of the flow charts of the control method of the refrigeration equipment provided in the embodiment of the present application;

[0039] Figure 2 Schematic diagram of a drive circuit of a variable frequency compressor provided in an embodiment of the present application;

[0040] Figure 3 1 is a schematic diagram of a control circuit of a variable frequency compressor provided in an embodiment of the present application;

[0041] Figure 4 This is the second flow chart of the control method of the refrigeration equipment provided in the embodiment of the present application;

[0042] Figure 5 This is a schematic diagram of the principle of the control method of the refrigeration equipment provided in the embodiment of the present application;

[0043] Figure 6 is a schematic structural diagram of a control device for a refrigeration device provided in an embodiment of the present application;

[0044] Figure 7 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0046] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0047] The following, in conjunction with the accompanying drawings, describes in detail the control method for refrigeration equipment, the control device for refrigeration equipment, the electronic device, and the readable storage medium provided in the embodiments of the present application through specific embodiments and their application scenarios.

[0048] The control method for the refrigeration equipment may be applied to a terminal, and may be specifically executed by hardware or software in the terminal.

[0049] The terminal includes, but is not limited to, a portable communication device such as a mobile phone or tablet computer having a touch-sensitive surface (e.g., a touch screen display and / or a touch pad). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but a desktop computer having a touch-sensitive surface (e.g., a touch screen display and / or a touch pad).

[0050] In the following embodiments, a terminal including a display and a touch-sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, a mouse, and a joystick.

[0051] The control method for a refrigeration device provided in an embodiment of the present application may be executed by a refrigeration device, or may be an electronic device connected to the refrigeration device, or may be a functional module or functional entity in the refrigeration device or the electronic device that can implement the control method for the refrigeration device. The electronic devices mentioned in the embodiment of the present application include but are not limited to mobile phones, tablet computers, computers, cameras, and wearable devices. The control method for a refrigeration device provided in an embodiment of the present application is described below using an electronic device as an example of the execution subject.

[0052] like Figure 1 As shown, the control method of the refrigeration equipment includes: step 110, step 120 and step 130.

[0053] It should be noted that the refrigeration equipment may include a wall-mounted air conditioner, a floor-standing air conditioner, a central air conditioner or a window air conditioner, etc.

[0054] The refrigeration equipment may include a connected controller and compressor.

[0055] Step 110: When the compressor is in operation, the controller calculates a target carrier frequency based on load information corresponding to the compressor and the actual ambient temperature of the environment in which the compressor is located.

[0056] In this step, the real-time load of the compressor (such as the effective value of current, exhaust pressure and power factor, etc.) can be obtained through feedback from the current sensor, pressure sensor or power module.

[0057] The load information may include a load rate, which may be a ratio of an effective current value to a rated current value, or a power utilization rate, etc. The load rate may be used to characterize the real-time working status of a motor or inverter (such as light load, full load, or overload).

[0058] For example, when the current is close to the rated value and the system needs to output full power, the system can be determined to be heavily loaded; when the current is between 50% and 80% of the rated value, the system can be determined to be moderately loaded; and when the current is 30% lower than the rated value, the system can be determined to be lightly loaded.

[0059] A temperature sensor may be provided on the compressor to collect the actual ambient temperature of the environment in which the compressor is located.

[0060] The target carrier frequency can be calculated based on load information, actual ambient temperature and user settings.

[0061] Among them, user settings may include optional parameter configurations.

[0062] Step 120: The controller modulates the target carrier frequency to obtain a target frequency signal.

[0063] In this step, random carrier technology can be used to modulate the target carrier frequency so that the target carrier frequency randomly jitters within a certain range to disperse harmonic energy.

[0064] For example, a target frequency signal may be obtained by modulating the target carrier frequency, so that the target frequency signal varies randomly within the range of 8 kHz ± 0.5 kHz, thereby reducing the amplitude of a specific subharmonic.

[0065] By modulating the target carrier frequency, the digital frequency instruction can be converted into an analog electrical signal. For example, a PWM waveform (pulse width modulation signal) can be output to control the on and off of the inverter switching device based on the PWM waveform, thereby adjusting the output voltage or frequency.

[0066] Step 130: The controller controls the speed of the compressor based on the target frequency signal.

[0067] In this step, the target frequency signal may be a PWM signal, which may be amplified to a power level to drive an inverter. The inverter may convert DC power into AC power, and its frequency and voltage may determine the motor speed of the compressor.

[0068] According to the control method of the refrigeration equipment provided in the embodiment of the present application, by automatically identifying the load information of the compressor and dynamically adjusting the carrier frequency of the frequency conversion controller according to the load information, ambient temperature conditions and the operating load of the whole machine, the switching loss can be minimized while ensuring the output accuracy. By modulating the target carrier frequency to obtain the target frequency signal, the energy of a single frequency can be dispersed to a wider frequency band, so that the spectrum is diffused, the interference peak at a specific frequency point is reduced, the electromagnetic interference and electromagnetic noise are reduced, and the user experience is improved.

[0069] In some embodiments, step 120 may include:

[0070] Get the target jitter frequency;

[0071] The target jitter frequency is added to the target carrier frequency to obtain the target frequency signal.

[0072] In this embodiment, the target jitter frequency may be a sine wave, a triangle wave, a jitter frequency generated based on a random number, or any other form of jitter frequency, which may be selected based on user needs and is not limited in this application.

[0073] The target jitter frequency can be used as a modulation signal and superimposed on the target carrier frequency by frequency modulation to obtain a target frequency signal. The modulation method can be customized based on user needs and is not limited in this application.

[0074] In some embodiments, obtaining the target jitter frequency may include:

[0075] Determine the frequency jittering step size and frequency jittering range based on the target carrier frequency and load information;

[0076] Within the frequency jitter range, the target jitter frequency is calculated based on the frequency jitter step size.

[0077] In this embodiment, a pseudo-random number generator may be used to generate a pseudo-random sequence. For example, a linear feedback shift register (LFSR) or a random number generator built into an MCU may be used to generate a uniformly distributed pseudo-random sequence.

[0078] The frequency jittering step size can be calculated based on the target carrier frequency: Δf_step = ±0.5% × f_carrier, where f_carrier is the target carrier frequency, ±0.5% means that the step size of each frequency adjustment is 0.5% of the target carrier frequency, and the direction can be positive or negative (i.e., the frequency can be increased or decreased).

[0079] By adjusting the target carrier frequency in small steps, the spectrum energy can be prevented from being concentrated at a single frequency point, thereby reducing electromagnetic interference.

[0080] The target jitter frequency can be calculated based on the jitter step size and random number: Δf = (LFSR_output%7) × Δf_step, where LFSR_output is a 16-bit random number generated by the LFSR (ranging from 0 to 65535), Δf_step is the jitter step size, and %7 is the modulo 7 of the random number. The random number can be discretized into integers from 0 to 6, corresponding to seven discrete jitter levels.

[0081] The mapping logic is:

[0082] LFSR_output%7=0→Δf=0 (no offset);

[0083] LFSR_output%7=3→Δf=3×0.5%×f_carrier=+1.5%f_carrier;

[0084] LFSR_output%7=6→Δf=6×0.5%×f_carrier=+3.0%f_carrier.

[0085] Mapping continuous random numbers to a finite number of levels (7 levels) can reduce computational complexity while ensuring the spectrum diffusion effect.

[0086] In actual application, the random number sign bit or alternation strategy can be combined to achieve ± direction offset (such as odd numbers are positive and even numbers are negative).

[0087] The maximum offset of the target jitter frequency can be calculated based on the 7-level step size: (0-6)×0.5%=3.5%. The jitter frequency range can be set to: ±3.5%×f_carrier. The target jitter frequency can be calculated within the jitter frequency range.

[0088] By controlling the frequency to jitter within the frequency jitter range, it is possible to avoid the situation where excessive frequency offset causes current loop control instability (for example, when PWM drives a motor, sudden frequency changes may cause harmonic resonance).

[0089] Based on the load information, the allowable range of the offset can be determined, and the amplitude of the generated pseudo-random sequence can vary within the allowable range. When the target jitter frequency is determined, the target jitter frequency can be superimposed on the target carrier frequency to obtain a modulated frequency signal.

[0090] When it is determined based on load information that the system load is high and the system is more sensitive to current ripple, the frequency jittering step size can be reduced, such as from ±0.5% to ±0.3%, to avoid current loop instability.

[0091] When the load rate is determined to be close to a threshold value (such as 90%) based on the load information, the frequency jittering range can be further limited. For example, the frequency jittering range can be tightened from ±3.5% to ±2.5%, thereby effectively preventing harmonics from causing heat loss or oscillation.

[0092] In some embodiments, when the load rate changes, the update frequency of the LSFR can be adjusted, for example, it can be updated from every 10 PWM cycles to every 5 PWM cycles to respond more quickly to changes in working conditions.

[0093] In the actual execution process, for example, the target carrier frequency f_carrier = 10kHz, the frequency jittering step Δf_step = 0.5% × 10kHz = 50Hz, the maximum frequency offset Δf = 3.5% × 10kHz = 0.35kHz, and the random number generated by the LFSR is 32987 (corresponding to 32987% 7 = 3). The current target jittering frequency is: 3 × 50Hz = +0.15kHz, and the actual carrier frequency becomes 10.15kHz.

[0094] The random number can be mapped to a carrier frequency variation range, such as ±Δf, where the target jitter frequency Δf = 500 Hz to 2 kHz. For example, when the base frequency is 6 kHz and Δf = 1 kHz, the carrier frequency can randomly jump between 5 kHz and 7 kHz.

[0095] In the case of using a linear feedback shift register (LFSR) to generate a pseudo-random sequence, the parameters of the LFSR can be defined based on the following method:

[0096] The register bit number is defined as 16 bits (to meet the period length requirement of the pseudo-random sequence); the feedback polynomial is defined as: x^16+x^14+x^13+x^11+1 (primitive polynomial used to ensure a maximum period of 2^16-1); the initial seed is defined as a non-all-zero value (such as 0xACE1), and the seed value is initialized using the temperature sensor noise source to avoid the repetitive spectral characteristics caused by a fixed seed; the update frequency is defined as once every 10 PWM cycles.

[0097] The use of 16-bit LFSR can reduce the computational overhead while ensuring randomness. Its cycle length (2 16 -1=65535 times) far exceeds the actual operating requirements (typical working conditions <1000 times / second).

[0098] According to the control method of the refrigeration equipment provided in the embodiment of the present application, the frequency jittering step and the frequency jittering range are generated by the target frequency signal and the load information, so that the target jittering frequency is generated based on the frequency jittering step within the frequency jittering range, which can avoid the situation where the current loop control is unstable due to excessive frequency offset, and the target jittering frequency is adjusted in real time based on the load information, which can effectively avoid the situation where heat loss or oscillation caused by harmonics when the system is highly loaded.

[0099] In some embodiments, obtaining the target jitter frequency may include:

[0100] Obtain the maximum offset between the modulated signal and the target carrier frequency;

[0101] Based on the amplitude and maximum offset of the modulating signal, the target dither frequency is determined.

[0102] In this embodiment, the modulation signal may be a low-frequency modulation signal, for example, a low-frequency (eg, 100-500 Hz) sine wave or a triangle wave.

[0103] For example, a single frequency sine wave can be used to obtain the target frequency signal:

[0104] f carrier (t) = f0 + Δf·sin(2πf mod t)

[0105] Among them, f carrier (t) is the target frequency signal, f0 is the center frequency corresponding to the target carrier frequency (fixed frequency when not modulated), Δf is the maximum offset corresponding to the target carrier frequency (the maximum amplitude of the frequency offset, that is, the maximum change of the carrier frequency relative to the center frequency), f mod is the frequency of the modulation signal, that is, the frequency of the signal that controls the frequency change, sin(2πf mod t) is the modulation signal.

[0106] In some embodiments, a set of discrete frequency steps (such as ±100 Hz, ±200 Hz, and ±300 Hz) can be preset, and then a frequency step is randomly selected as the target dithering frequency in each PWM cycle, and the target dithering frequency is added to the current carrier frequency. The frequency range can be limited, for example, to ensure that the carrier frequency dithers within 5 kHz to 7 kHz.

[0107] In some embodiments, center-aligned PWM can be used to sample the current at the midpoint of the PWM cycle (50% duty cycle position) so that the inductor current is at the average value point, which can minimize switching noise interference and avoid sampling deviation caused by frequency changes.

[0108] In some embodiments, the current loop bandwidth may be increased to speed up the system response and suppress the impact of high-frequency current ripple caused by the addition of frequency jittering.

[0109] In some embodiments, a low-pass filter (such as a first-order IIR filter) may be added to the current loop input to attenuate high-frequency ripples.

[0110] In actual implementation, the disturbance problem caused by coupling can be avoided by adjusting the control parameters of the current loop, increasing the bandwidth or increasing the integral control coefficient.

[0111] In some embodiments, control logic such as temperature over-limit protection, over-current protection, and current distortion rate protection may be added to the control function to trigger frequency reduction or shutdown when an abnormality occurs.

[0112] In this embodiment, the temperature of the power device can be monitored in real time, and when the temperature exceeds a threshold, the frequency jitter amplitude is reduced or switched to a fixed frequency.

[0113] A dynamic overcurrent threshold can be set (taking into account the peak-to-peak value of the ripple), which will immediately shut down the PWM and report an error when triggered.

[0114] The current distortion rate can be calculated through FFT or THD, and the frequency jitter parameters can be adjusted or the machine can be shut down when the limit is exceeded.

[0115] In the event of an abnormality, the switching frequency can be reduced to a safe range as a priority; if it cannot be restored, the machine will be shut down and a fault code will be reported.

[0116] In this application, by adding control logic such as temperature over-limit protection, overcurrent protection, and current distortion rate protection to the control function, frequency reduction or shutdown can be triggered when an abnormality occurs, which can effectively avoid problems such as current distortion, excessive temperature rise, or overcurrent caused by the addition of frequency jitter control.

[0117] In some embodiments, step 110 may include:

[0118] Based on the load information and the actual ambient temperature, searching a preset relationship table for a candidate carrier frequency corresponding to the interval in which the load information is located and the interval in which the actual ambient temperature is located;

[0119] The candidate carrier frequency is determined as the target carrier frequency.

[0120] In this embodiment, the preset relationship table may be a two-dimensional mapping table, which is used to define the corresponding relationship between the load interval, the temperature interval and the candidate carrier frequency.

[0121] Table 1 shows an example of a preset relationship table:

[0122] Table 1

[0123] Load rate η Actual ambient temperature T Candidate carrier frequency f_carrier η≤30% T≥40℃ 4kHz 30%<η≤60% 25℃≤T<40℃ 6kHz η>60% T<25℃ 8kHz

[0124] The real-time load value (such as the effective value of the current) is obtained through the current sensor or power calculation, and the range in which the load information is located can be determined. For example, when 0≤load rate≤30%, it can be determined to be in the low load range; when 30%<load rate≤60%, it can be determined to be in the medium load range; when the load rate is greater than 60%, it can be determined to be in the high load range.

[0125] The actual ambient temperature can be obtained through an NTC thermistor or a digital temperature sensor, and the range of the actual ambient temperature can be determined. For example, when the actual ambient temperature is <25°C, it can be determined to be in the low temperature range; when the actual ambient temperature is 25°C ≤ the actual ambient temperature <40°C, it can be determined to be in the normal temperature range; when the actual ambient temperature is ≥40°C, it can be determined to be in the high temperature range.

[0126] According to the current load range and temperature range, a unique matching candidate carrier frequency can be found from the preset relationship table. For example, when the current load rate = 50% (medium load range) and the actual ambient temperature is 30°C (normal temperature range), the candidate carrier frequency corresponding to the current load range and temperature range can be determined to be 6kHz, and it can be determined as the target carrier frequency.

[0127] In some embodiments, step 110 may include:

[0128] When the load information and / or the actual ambient temperature is updated from the first interval to the second interval in the preset relationship table, obtaining difference information between the load information and / or the actual ambient temperature and a boundary threshold corresponding to the second interval;

[0129] If it is determined that the difference information is less than or equal to the target difference threshold, determining the candidate carrier frequency corresponding to the first interval as the target carrier frequency;

[0130] If it is determined that the difference information is greater than the target difference threshold, the candidate carrier frequency corresponding to the second interval is determined as the target carrier frequency.

[0131] In this embodiment, when it is determined that the load information and / or the actual ambient temperature increases, the boundary threshold corresponding to the second interval is the lower boundary threshold of the second interval; when it is determined that the load information and / or the actual ambient temperature decreases, the boundary threshold corresponding to the second interval is the upper boundary threshold of the second interval.

[0132] When the load / temperature changes from a low range to a high range (such as low temperature to normal temperature), it can be determined that the load information and / or the actual ambient temperature increases; when the load / temperature changes from a high range to a low range (such as high temperature to normal temperature), it can be determined that the load information and / or the actual ambient temperature decreases.

[0133] When the load or temperature changes across intervals (eg, from a low load region to a medium load region), a difference comparison process may be initiated.

[0134] like Figure 5 As shown, when the load information and / or the actual ambient temperature increases, the difference between the current value and the lower boundary of the new interval can be compared. For example, the load increases from 25% (low load area) to 35% (medium load area), the lower boundary is 30%, and the difference = 35% - 30% = 5%.

[0135] The temperature drops from 45°C (high temperature zone) to 35°C (normal temperature zone), with the upper boundary being 40°C, and the difference = 40°C - 35°C = 5°C.

[0136] The target difference threshold may include a load difference threshold and a temperature difference threshold, wherein the load difference threshold may be set to 2%, and the temperature difference threshold may be set to 1° C., or may be set to other values, which are not limited in this application.

[0137] For example, when the load factor increases from 29% to 31%, the current target carrier frequency may be kept unchanged; and when the load factor exceeds 32%, 6 kHz may be determined as the new target carrier frequency.

[0138] When the actual ambient temperature rises from 39°C to 41°C, the current target carrier frequency may be kept unchanged. When the actual ambient temperature exceeds 42°C, 4 kHz may be determined as the new target carrier frequency.

[0139] According to the control method for refrigeration equipment provided in the embodiment of the present application, by setting a difference threshold and a hysteresis mechanism, it is determined whether the target carrier frequency needs to be adjusted according to whether the change in load information or actual ambient temperature is in the hysteresis interval, and the short-term fluctuations of the filtering parameters at the interval boundary can be avoided. This can avoid current harmonics and system oscillations caused by frequent switching of the carrier frequency, and can independently configure the difference thresholds of load and temperature to adapt to a variety of different working conditions.

[0140] In some embodiments, the target carrier frequency may be adjusted based on the current harmonic distortion rate until the current harmonic distortion rate reaches a set value.

[0141] In this embodiment, the current signal can be sampled at twice the switching frequency (eg, when f_carrier=10kHz, the sampling rate ≥ 20kHz), and FFT can be performed on the sampling data of the most recent power frequency cycle (50Hz / 60Hz) to calculate the amplitudes of the fundamental and harmonic components.

[0142] The current harmonic distortion rate may be approximated by a sliding window integration method, or may be calculated by other methods, which are not limited in this application.

[0143] The current harmonic distortion (THD) may be calculated every 100 ms. For example, when THD>8%, the target carrier frequency is controlled to increase, for example, by 5%-10%, until THD≤8%.

[0144] like Figure 4 As shown, in some embodiments, the method may include:

[0145] Based on the target carrier frequency, generating a PWM signal corresponding to the target carrier frequency;

[0146] The compressor is controlled to operate based on a PWM signal.

[0147] In this embodiment, the PWM generation module can dynamically adjust the timer value based on the MCU instruction to update the carrier frequency to the target carrier frequency, and then generate a PWM waveform corresponding to the target carrier frequency (such as center alignment or edge alignment).

[0148] The power drive module can amplify the PWM signal to a power level to drive the compressor motor or load.

[0149] like Figure 2The invention provides an example of a drive circuit for a variable frequency compressor, including an EMI filter circuit, a voltage rectification module, a PFC control module, an IPM power inverter module and an MCU control unit.

[0150] In this embodiment, the EMI filter circuit is used to suppress electromagnetic interference (EMI) generated by electronic equipment, while preventing external interference from affecting the device itself, ensuring that the device complies with electromagnetic compatibility (EMC) standards. The EMI filter circuit can "filter" noise signals in a specific frequency band to block or attenuate interference energy, complementing "random frequency jittering". Random frequency jittering disperses energy EMI peaks, while the EMI filter directly blocks the noise propagation path. The two can be used in combination to enhance anti-interference capabilities.

[0151] The use of random frequency jittering technology in variable frequency drive control can reduce the design specifications of EMI filter circuits while meeting EMC test standards at a lower cost.

[0152] The voltage rectifier module is used to rectify the AC voltage into a DC voltage.

[0153] PFC control includes passive PFC (passive PFC) and active PFC (active PFC). Passive PFC uses inductors and capacitors to compensate for phase differences. It has low cost but average efficiency, with a PF value of approximately 0.7-0.8. Inverter air conditioners generally use active PFC, which dynamically adjusts the current waveform through control chips and IGBTs. It has high efficiency and a PF value of up to 0.95-0.99.

[0154] The IPM power inverter module can be used for power conversion and can achieve efficient conversion (inversion) between DC and AC, or adjust voltage / frequency through the high-speed switching of the internal IGBT.

[0155] like Figure 3 The example shows the FOC drive control block diagram of a variable frequency compressor. When the compressor is running, the two-phase current of the compressor can be sampled. The current signal is input to the MCU control unit through an operational amplifier. After the Clarke / Park transformation, the three-phase current is converted into two-phase currents Iα, Iβ, Id and Iq. The compressor rotor position and rotor speed are estimated through a sliding mode observer. The q-axis current loop and d-axis current loop are controlled by a PI controller, and the estimated speed and target speed are controlled through the speed PI loop. After PI iteration, the two components of the voltage vector in the rotating dq coordinate system can be obtained.

[0156] The two components of the voltage vector are then transformed back to the three-phase motor voltage through an inverse transformation: the two-axis rotating dq coordinate system can be transformed into a two-axis stationary α-β coordinate system through the Park inverse transformation, and then the stationary α-β coordinate system can be transformed into the stator stationary 3-axis and 3-phase reference coordinate system through the CLARKE inverse transformation to generate the three-phase voltages Vr1, Vr2 and Vr3 for compressor operation.

[0157] The MCU control unit can be used to generate and modulate PWM signals. It can calculate and output PWM (pulse width modulation) waveforms in real time according to the target carrier frequency and voltage (Vr1, Vr2 and Vr3), control the switching timing of IGBT / MOSFET in the IPM module, and adjust the output voltage / frequency.

[0158] The load rate calculation A can be introduced into the Clarke inverse transformation coordinate system conversion in the system control block diagram, such as Figure 3 As shown, the load rate calculation A can collect and calculate the load rate (η) and actual ambient temperature (T) of the compressor in real time, and dynamically calculate the optimal carrier frequency (f_carrier) according to the load rate and the actual ambient temperature conditions. Among them, the load rate calculation A can calculate the load rate of the current system by measuring the motor phase current (such as Ia, Ib and Ic) or voltage (Va and Vβ) combined with the adjustment of the PI controller.

[0159] A random carrier frequency generator B can be introduced into the Clarke inverse transform coordinate system conversion, such as Figure 3 As shown in Figure 3, by randomly modulating the carrier frequency, the harmonic energy can be dispersed into a wider frequency band, reducing the peak amplitude and thus reducing the high-frequency noise of the motor.

[0160] In this application, by combining sensorless FOC, dynamic carrier frequency and software frequency jittering to control the variable frequency operation of the compressor, the EMI filter circuit design parameters are reduced, the cost is reduced, and the carrier frequency is dynamically matched to the load requirements, reducing the switching loss and the temperature rise of the IPM inverter. The fundamental frequency is iterated and random carrier frequency is formed to form a frequency jittering control mechanism, which reduces EMI interference and electromagnetic noise.

[0161] The control method for the refrigeration equipment provided in the embodiment of the present application can be transplanted to any MCU platform that supports FOC (such as ARM Cortex-M4 / M7), and this application does not limit it.

[0162] According to the inventor's test, the control method of the refrigeration equipment provided in the embodiment of the present application can control the operation of the variable frequency air conditioner, which can operate stably at an ambient temperature of -10°C to 50°C, and the EMI test can pass the CISPR 25Class 3 limit test; and it has been verified that based on the comparison of the conducted radiation of the variable frequency controller measured in the range of 150kHz to 30MHz, the peak limit and average limit measured by the control method of the refrigeration equipment provided in the embodiment of the present application are both lower than the electromagnetic noise of the method in the related art.

[0163] The control device of the refrigeration equipment provided in the present application is described below. The control device of the refrigeration equipment described below and the control method of the refrigeration equipment described above can be referenced to each other.

[0164] The control method for refrigeration equipment provided in the embodiment of the present application can be executed by a control device of the refrigeration equipment. In the embodiment of the present application, the control device of the refrigeration equipment executing the control method for refrigeration equipment is used as an example to illustrate the control device of the refrigeration equipment provided in the embodiment of the present application.

[0165] An embodiment of the present application also provides a control device for refrigeration equipment.

[0166] like Figure 6 As shown, the control device of the refrigeration equipment includes a connected controller and a compressor; the device includes: a first processing module 610, a second processing module 620 and a third processing module 630.

[0167] The first processing module 610 is configured to calculate a target carrier frequency based on load information corresponding to the compressor and an actual ambient temperature of the environment in which the compressor is located when the compressor is in operation;

[0168] The second processing module 620 is configured to enable the controller to modulate the target carrier frequency to obtain a target frequency signal;

[0169] The third processing module 630 is configured to enable the controller to control the speed of the compressor based on the target frequency signal.

[0170] According to the control device of the refrigeration equipment provided in the embodiment of the present application, by automatically identifying the load information of the compressor, the carrier frequency of the frequency conversion controller is dynamically adjusted according to the load information, the ambient temperature conditions and the operating load of the whole machine, so as to minimize the switching loss while ensuring the output accuracy. By modulating the target carrier frequency to obtain the target frequency signal, the energy of a single frequency can be dispersed to a wider frequency band, so that the spectrum is diffused, the interference peak at a specific frequency point is reduced, the electromagnetic interference and electromagnetic noise are reduced, and the user experience is improved.

[0171] In some embodiments, the second processing module 620 may also be configured to:

[0172] Get the target jitter frequency;

[0173] The target jitter frequency is added to the target carrier frequency to obtain the target frequency signal.

[0174] In some embodiments, the second processing module 620 may also be configured to:

[0175] Determine the frequency jittering step size and frequency jittering range based on the target carrier frequency and load information;

[0176] Within the frequency jitter range, the target jitter frequency is calculated based on the frequency jitter step size.

[0177] In some embodiments, the second processing module 620 may also be configured to:

[0178] Obtain the maximum offset between the modulated signal and the target carrier frequency;

[0179] Based on the amplitude and maximum offset of the modulating signal, the target dither frequency is determined.

[0180] In some embodiments, the first processing module 610 may also be configured to:

[0181] Based on the load information and the actual ambient temperature, a candidate carrier frequency corresponding to the interval of the load information and the interval of the actual ambient temperature is searched from a preset relationship table; the preset relationship table is used to represent the mapping relationship between the interval of the load information, the interval of the actual ambient temperature and the candidate carrier frequency;

[0182] The candidate carrier frequency is determined as the target carrier frequency.

[0183] In some embodiments, the first processing module 610 may also be configured to:

[0184] When the load information and / or the actual ambient temperature are updated from the first interval to the second interval in the preset relationship table, obtaining difference information between the load information and / or the actual ambient temperature and a boundary threshold corresponding to the second interval; wherein, when it is determined that the load information and / or the actual ambient temperature have increased, the boundary threshold corresponding to the second interval is the lower boundary threshold of the second interval; and when it is determined that the load information and / or the actual ambient temperature have decreased, the boundary threshold corresponding to the second interval is the upper boundary threshold of the second interval;

[0185] If it is determined that the difference information is less than or equal to the target difference threshold, determining the candidate carrier frequency corresponding to the first interval as the target carrier frequency;

[0186] If it is determined that the difference information is greater than the target difference threshold, the candidate carrier frequency corresponding to the second interval is determined as the target carrier frequency.

[0187] The control device of the refrigeration equipment in the embodiment of the present application can be an electronic device or a component in the electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices other than a terminal. For example, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, a mobile Internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook or a personal digital assistant (PDA), etc. It can also be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), a teller machine or a self-service machine, etc., and the embodiment of the present application does not specifically limit it.

[0188] The control device of the refrigeration equipment in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0189] The control device of the refrigeration equipment provided in the embodiment of the present application can achieve Figures 1 to 5 To avoid repetition, the various processes implemented in the method embodiment are not described here.

[0190] In some embodiments, as Figure 7 As shown, an embodiment of the present application also provides an electronic device 700, including a processor 701, a memory 702, and a computer program stored in the memory 702 and executable on the processor 701. When the program is executed by the processor 701, each process of the control method embodiment of the above-mentioned refrigeration equipment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0191] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0192] In some embodiments, the present application also provides a refrigeration device, including: a compressor and a controller.

[0193] In this embodiment, the controller is connected to the compressor.

[0194] The controller can be used to execute the control method of the refrigeration equipment described in any of the above embodiments.

[0195] According to the refrigeration equipment provided in the embodiment of the present application, by automatically identifying the load information of the compressor and dynamically adjusting the carrier frequency of the frequency conversion controller according to the load information, ambient temperature conditions and the operating load of the whole machine, the switching loss can be minimized while ensuring the output accuracy. By modulating the target carrier frequency to obtain the target frequency signal, the energy of a single frequency can be dispersed to a wider frequency band, so that the spectrum is diffused, the interference peak at a specific frequency point is reduced, the electromagnetic interference and electromagnetic noise are reduced, and the user experience is improved.

[0196] On the other hand, the present application also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the various processes of the above-mentioned control method embodiment of the refrigeration equipment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0197] On the other hand, the present application also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it is implemented to perform the various processes of the above-mentioned control method embodiment of the refrigeration equipment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0198] On the other hand, an embodiment of the present application further provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned control method embodiment of the refrigeration equipment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0199] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0200] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0201] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling a refrigeration device, characterized in that: The refrigeration device includes a controller and a compressor connected; the controller is used to perform the following method: When the compressor is in operation, the controller calculates a target carrier frequency based on load information corresponding to the compressor and an actual ambient temperature in an environment where the compressor is located; The controller modulates the target carrier frequency to obtain a target frequency signal; The controller controls the rotation speed of the compressor based on the target frequency signal.

2. The control method for refrigeration equipment according to claim 1, characterized in that: The modulating the target carrier frequency to obtain a target frequency signal includes: Get the target jitter frequency; The target jitter frequency is superimposed on the target carrier frequency to obtain the target frequency signal.

3. The control method for refrigeration equipment according to claim 2, characterized in that: The obtaining of the target jitter frequency includes: Determining a frequency jittering step size and a frequency jittering range based on the target carrier frequency and the load information; Within the frequency jittering range, the target jittering frequency is calculated based on the frequency jittering step size.

4. The control method for refrigeration equipment according to claim 2, characterized in that: The obtaining of the target jitter frequency includes: Obtaining a maximum offset between the modulated signal and the target carrier frequency; The target dithering frequency is determined based on the amplitude of the modulation signal and the maximum offset.

5. The control method for refrigeration equipment according to any one of claims 1 to 4, characterized in that: The target carrier frequency is calculated based on the load information corresponding to the compressor and the actual ambient temperature of the environment in which the compressor is located, including: Based on the load information and the actual ambient temperature, searching a preset relationship table for a candidate carrier frequency corresponding to the interval in which the load information is located and the interval in which the actual ambient temperature is located; the preset relationship table is used to represent a mapping relationship between the interval in which the load information is located, the interval in which the actual ambient temperature is located, and the candidate carrier frequency; The candidate carrier frequency is determined as the target carrier frequency.

6. The control method for refrigeration equipment according to claim 5, characterized in that: The target carrier frequency is calculated based on the load information corresponding to the compressor and the actual ambient temperature of the environment in which the compressor is located, including: When the load information and / or the actual ambient temperature is updated from the first interval to the second interval in the preset relationship table, obtaining difference information between the load information and / or the actual ambient temperature and a boundary threshold corresponding to the second interval; wherein, when it is determined that the load information and / or the actual ambient temperature has increased, the boundary threshold corresponding to the second interval is a lower boundary threshold of the second interval; and when it is determined that the load information and / or the actual ambient temperature has decreased, the boundary threshold corresponding to the second interval is an upper boundary threshold of the second interval; If it is determined that the difference information is less than or equal to the target difference threshold, determining the candidate carrier frequency corresponding to the first interval as the target carrier frequency; If it is determined that the difference information is greater than the target difference threshold, the candidate carrier frequency corresponding to the second interval is determined as the target carrier frequency.

7. A refrigeration device, characterized in that: include: compressor; A controller is connected to the compressor, and the controller is used to execute the control method of the refrigeration equipment according to any one of claims 1 to 6.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the control method for the refrigeration equipment according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the control method for the refrigeration equipment according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the control method for the refrigeration equipment according to any one of claims 1 to 6 is implemented.

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