Compressor open-phase operation protection method and device, computer device and storage medium

Abstract

The application belongs to the technical field of intelligent electric control of air conditioners, and relates to a compressor open-phase operation protection method, which detects the open phase of the compressor at a preset time interval, detects that the compressor is in an open-phase operation state, obtains three-phase currents of the compressor, obtains peak currents according to the three-phase currents, obtains a stator winding temperature of the compressor, takes the stator winding temperature as a rotor temperature, and calculates a demagnetization current according to the rotor temperature; determines the operation state of the compressor based on the demagnetization current and the peak current; and controls the compressor to execute corresponding protection instructions according to the operation state. The application also relates to a compressor open-phase operation protection device, a computer device and a storage medium. The technical scheme provided by the application can monitor and analyze key factors under open-phase operation, so that the compressor can be protected and the potential of the compressor under the open-phase operation state can be tapped as much as possible, so that the compressor can operate with faults within a safe range and the probability of product failure and shutdown can be reduced.

Description

Technical Field

[0001] This application relates to the field of intelligent electronic control technology for air conditioning, and more specifically, to a method, device, computer equipment, and storage medium for protecting a compressor from phase loss. Background Technology

[0002] During compressor operation, a single phase loss may occur in the motor, such as a broken coil, poor contact between the terminal block and the wiring terminal, or loosening and detachment. The compressor can still operate even with one phase missing, but the current in the other two phases will increase. In the current waveform changes, because one phase has no current output, the motor operates abnormally. Prolonged operation in this state will lead to increased output power, overheating, and damage to the compressor and motor components.

[0003] Currently, for compressor phase loss protection during operation, two main protection methods are generally used in control: one is based on the duration of the phase loss, and the other is based on the current of the remaining two phases after the phase loss. For example, if the compressor is detected to have a continuous phase loss for a certain period (typically 10 seconds), the compressor will stop running and a fault shutdown code will be reported; or, if the compressor phase current is detected to be greater than a preset current (which varies depending on the compressor), the compressor will stop running and a fault shutdown code will be reported. However, the above protection methods have the following drawbacks:

[0004] When a phase is lost during compressor operation, if the protection method used is based on the duration of the phase loss, the air conditioner will automatically abandon its function of continuing operation under phase loss. When encountering issues such as aging wiring or poor contact, a short-term phase loss may occur. If the unit quickly reports a fault and shuts down in this situation, it will affect user experience. This is particularly detrimental to users in situations where after-sales support is inconvenient or labor costs are high.

[0005] When a compressor experiences a phase loss during operation, comparing the detected compressor phase current with a preset protection current for protection may lead to a mismatch between current and heat generation. This is because compressors differ from ordinary fans or other motors. Fans, for example, generate heat primarily based on the current in their windings; higher current results in greater heat generation, allowing for protection with a preset current protection value. However, compressors contain refrigerant that carries away heat generated within the compressor. This heat dissipation rate is directly proportional to the refrigerant flow rate. Therefore, when the compressor current is low, the corresponding rotational speed may also be low, resulting in low refrigerant flow and poor compressor heat dissipation. Consequently, the heat generated in this situation may be greater than when the current is high. Therefore, current protection alone cannot adequately address the temperature protection function of compressors operating under phase loss conditions. Summary of the Invention

[0006] The technical problem to be solved by this application is that there is no compressor protection method in the prior art that can both protect the compressor in the single-phase operation state and allow it to operate with faults within a safe range.

[0007] To address the aforementioned technical problems, this application provides a compressor phase loss protection method, which employs the following technical solution:

[0008] The compressor is subjected to phase loss detection at a preset time interval. If the compressor is detected to be in a phase loss operation state, the three-phase current of the compressor is obtained, and the peak current is obtained based on the three-phase current.

[0009] The stator winding temperature of the compressor is obtained, and the stator winding temperature is used as the rotor temperature of the rotor that is in the same plane as the stator winding. The demagnetizing current is calculated based on the rotor temperature.

[0010] The operating status of the compressor is determined based on the demagnetizing current and the peak current;

[0011] The compressor is controlled to execute corresponding protection commands based on the operating status.

[0012] Furthermore, the step of obtaining the three-phase current of the compressor and obtaining the peak current based on the three-phase current includes:

[0013] The voltage signals corresponding to the three compressor components are acquired by sampling resistors;

[0014] Based on the voltage signal, the three-phase current is calculated using a frequency conversion control algorithm;

[0015] The maximum current value among the three-phase currents is taken as the peak current.

[0016] Furthermore, the step of obtaining the demagnetizing current of the compressor includes:

[0017] Detect the current thermal resistance of the compressor;

[0018] The stator winding temperature of the compressor is calculated based on the thermal resistance.

[0019] Furthermore, the step of detecting the current hot resistance of the compressor includes:

[0020] By superimposing DC component voltages onto the original three-phase AC voltage of the compressor, the corresponding superimposed AC voltage is obtained;

[0021] Based on the superimposed AC voltage, a corresponding phase sampling current is generated within a preset time period;

[0022] Perform a Fourier transform on the sampled phase current to obtain the corresponding DC component current of the phase.

[0023] The current hot resistance is obtained based on the DC component voltage and the DC component current.

[0024] Furthermore, the step of calculating the stator winding temperature of the compressor based on the thermal resistance includes:

[0025] Obtain the cold resistance and pre-operation temperature of the compressor;

[0026] The stator winding temperature is calculated based on the cold resistance, the pre-operation temperature, and the hot resistance.

[0027] Furthermore, the step of determining the operating state of the compressor based on the demagnetizing current and the peak current includes:

[0028] The current operating value is calculated based on the demagnetizing current and the peak current;

[0029] The operating status of the compressor is determined based on the current operating value; wherein the operating status includes safe status, frequency limiting status, temperature limiting status, and dangerous status.

[0030] Furthermore, the step of executing the corresponding protection instruction based on the operating state includes:

[0031] Obtain the current operating frequency of the compressor;

[0032] When the operating state is a safe state, the compressor is controlled to operate normally;

[0033] When the operating state is frequency limiting state, if the current operating frequency is greater than or equal to a preset frequency value, the current operating frequency is restricted from continuing to increase; if the current operating frequency is less than the preset frequency value, the current operating frequency is restricted from continuing to decrease.

[0034] When the operating state is a temperature-limited state, if the current operating frequency is greater than or equal to a preset frequency value, the current operating frequency is reduced; if the current operating frequency is less than the preset frequency value, the current operating frequency is increased.

[0035] When the operating state is dangerous, the compressor is shut down and a fault alarm signal is output.

[0036] To address the aforementioned technical problems, this application also provides a compressor phase loss protection device, which employs the following technical solution:

[0037] The detection module is used to perform phase loss detection on the compressor at preset time intervals. If the compressor is detected to be in a phase loss operation state, the module acquires the three-phase current of the compressor and obtains the peak current based on the three-phase current.

[0038] The acquisition module is used to obtain the stator winding temperature of the compressor, use the stator winding temperature as the rotor temperature of the rotor that is in the same plane as the stator winding, and calculate the demagnetizing current based on the rotor temperature.

[0039] A status determination module is used to determine the operating status of the compressor based on the demagnetizing current and the peak current;

[0040] The protection execution module is used to control the compressor to execute corresponding protection commands based on the operating status.

[0041] To address the aforementioned technical problems, this application also provides a computer device that employs the following technical solution:

[0042] The computer device includes a memory and a processor. The memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the steps of the compressor phase loss operation protection method as described above.

[0043] To address the aforementioned technical problems, this application also provides a computer-readable storage medium, employing the technical solution described below:

[0044] The computer-readable storage medium stores computer-readable instructions, which, when executed by a processor, implement the steps of the compressor phase loss protection method described above.

[0045] Compared with the prior art, this application has the following main advantages:

[0046] This application obtains the maximum current value among the three-phase currents of the compressor under phase-loss operation, and obtains the operating status based on the maximum current value and the compressor's demagnetizing current. Based on the operating status, the compressor is controlled to execute corresponding protection commands. This avoids the one-size-fits-all protection method under phase-loss operation, and can monitor and analyze key factors under phase-loss operation. This allows the compressor to be protected while maximizing its potential under phase-loss operation, enabling it to operate with faults within a safe range and reducing the probability of product failure and shutdown. Attached Figure Description

[0047] To more clearly illustrate the solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0048] Figure 1 This is a flowchart of an embodiment of the compressor phase loss operation protection method according to this application;

[0049] Figure 2 This is a schematic diagram showing the relationship between demagnetizing current and temperature according to an embodiment of the compressor phase loss protection method of this application;

[0050] Figure 3 This is a schematic diagram of a structure of an embodiment of the compressor phase loss protection device according to this application;

[0051] Figure 4 This is a schematic diagram of the structure of one embodiment of the computer device according to this application. Detailed Implementation

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0054] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0055] This application provides a method for protecting a compressor from phase loss operation; see [link to relevant documentation]. Figure 1 The flowchart illustrates an embodiment of a compressor phase loss protection method according to this application, including the following steps:

[0056] Step S101: Perform phase loss detection on the compressor at a preset time interval. If the compressor is detected to be in a phase loss operation state, obtain the three-phase current of the compressor and obtain the peak current based on the three-phase current.

[0057] The feature of performing phase loss detection on the compressor at preset time intervals can better protect the compressor while ensuring its operation. The preset time interval can be set to 1 second, 2 seconds, 3 seconds, etc., depending on the specific situation.

[0058] Within a preset time interval, the drive control chip is activated. The control chip determines whether the compressor is missing a phase based on the current value detected by the current detection circuit in the three-phase winding of the compressor. Specifically, if the detected current value is less than or equal to the preset current value, it indicates that the compressor is in a phase-missing operation state.

[0059] It should be noted that the preset current value is the single-phase operation threshold of the compressor, which can be 0, but considering the detection error, it can be slightly larger than 0.

[0060] After detecting that the compressor is operating in a single-phase state, the three-phase current of the compressor is obtained, and the peak current is obtained based on the three-phase current.

[0061] Specifically, the voltage signals of the three phases of the compressor are collected by sampling resistors; based on the voltage signals, the three-phase current is calculated by a frequency conversion control algorithm; and the maximum current value is determined based on the three-phase current.

[0062] The compressor phase current generates a corresponding voltage signal through a sampling resistor. The control chip acquires this voltage signal and uses an FOC (Field Oriented Control) frequency converter control algorithm to calculate the three-phase currents, Ia, Ib, and Ic, based on the resistance value of the sampling resistor and the voltage signal value. The largest current value is taken as the peak current Ic. peak .

[0063] Among them, the FOC frequency conversion control algorithm is currently the mainstream brushless DC motor control algorithm.

[0064] This embodiment uses a frequency conversion control algorithm to calculate the peak current based on the collected voltage signal. The calculation process is simple and can improve calculation efficiency.

[0065] Step S102: Obtain the stator winding temperature of the compressor, use the stator winding temperature as the rotor temperature of the rotor which is in the same plane as the stator winding, and calculate the demagnetizing current based on the rotor temperature.

[0066] When the compressor operates in a phase loss state, the increased current in the stator windings of the other two phases leads to a rapid accumulation of heat in the coils. Since the stator windings and rotor magnets are on the same horizontal plane, the heat from the stator windings is more easily transferred to the rotor magnets. The temperature resistance of the stator windings is determined by the specifications of the enameled wire, and generally, the temperature resistance value is greater than the maximum temperature in the demagnetization current diagram. The demagnetization current of the rotor windings varies at different temperatures, and the demagnetization current of the rotor magnets is used as the demagnetization current of the compressor.

[0067] The relationship between the demagnetizing current and temperature of the compressor is pre-fitted, and the fitting relationship is y = k*T. Magnet +b, where T Magnet The temperature of the rotor magnet (i.e., the rotor temperature) can be used to calculate the demagnetizing current.

[0068] For example, see Figure 2 This illustrates the relationship between the demagnetizing current and temperature of a compressor. Based on the figure, the fitting result of the relationship between the compressor's demagnetizing current and temperature is I. Demage =-1.58×T Magnet +294.87, of which, I Demage Given the demagnetizing current, based on experience, the fitting result is transformed into a piecewise function, resulting in:

[0069]

[0070] In the formula, 1A indicates that the compressor will be immediately stopped when the rotor temperature is greater than or equal to 160℃.

[0071] In some embodiments, the step of obtaining the stator winding temperature of the compressor includes:

[0072] Detect the current hot resistance of the compressor;

[0073] Calculate the stator winding temperature of the compressor based on the thermal resistance.

[0074] The resistance of the conductor changes with temperature. During the operation of the compressor, heat is released, which raises the temperature of the motor stator winding. It is necessary to detect the current hot resistance R2 of the motor stator winding.

[0075] Specifically, a DC component voltage is superimposed on the original three-phase AC voltage of the compressor to obtain the corresponding superimposed AC voltage; a phase sampling current is generated within a preset time based on the superimposed AC voltage; a Fourier transform is performed on the phase sampling current to obtain the DC component current of the corresponding phase; and the current hot resistance is obtained based on the DC component voltage and the DC component current.

[0076] Let the phase voltage output by the original FOC frequency converter control algorithm be:

[0077] Ua = U0 * cos(ωt),

[0078] Ub=U0*cos(ωt–2π / 3),

[0079] Uc = U0 * cos(ωt + 2π / 3)

[0080] A DC component voltage Ur is superimposed on Ua, Ub, and Uc respectively. Assuming the current compressor operating frequency is Freq1, then one cycle time Tcycle = 1 / Freq1. If the output of this DC component voltage Ur is maintained for a time period of 5 × Tcycle (a preset time), then the phase voltage output by the FOC becomes:

[0081] Ua'=U0*cos(ωt)+Ur,

[0082] Ub'=U0*cos(ωt–2π / 3)+Ur,

[0083] Uc'=U0*cos(ωt+2π / 3)+Ur

[0084] Based on the fact that the input voltage passes through the compressor motor windings at this time, corresponding phase sampling currents Ia, Ib and Ic will be generated.

[0085] Ur is a preset value, which can be selected according to the actual situation.

[0086] It should be understood that the compressor is in a single-phase operation state, and no current is generated in the missing phase. Therefore, the phase sampling current is 0. For example, assuming that phase B is missing, phases A and C are the operating phases. The corresponding phase sampling currents Ia and Ic generated within the preset time 5×Tcycle are collected.

[0087] It should be noted that, in order to reduce the burden on the control chip, according to the sampling theorem, "the sampling frequency must be greater than or equal to twice the operating frequency in order to recover its actual waveform", the storage density of Ia, Ib and Ic is diluted.

[0088] For example, when the carrier frequency is 6KHz, the compressor frequency is 60Hz, and the number of compressor pole pairs is 3, the corresponding compressor phase current frequency is 180Hz, and the number of sampling points within 5×Tcycle reaches 166 points. However, when sampling points are taken with a sampling period of 10 times that, only 50 points need to be sampled.

[0089] Using the Fast Fourier Transform (FFT) principle, the 50 stored points are processed by FFT to convert the time-domain signal into a frequency-domain signal, which yields a phase DC component current Ir and the amplitude I0 of the alternating current at that frequency.

[0090] For example, assuming the compressor operates at a frequency of 60Hz and is a 3-pole permanent magnet synchronous motor, when Ua, Ub, and Uc are outputting normally, the current should be a 180Hz sine wave, which can be modeled using Ia=A*sin(2*π*180*t). When Ua, Ub, and Uc are superimposed with Ur components, they can be modeled using Ia'=A*sin(2*π*180*t)+B, where t is time in milliseconds.

[0091] By performing FFT operations on Ia and Ia', their spectral data can be obtained. The DC component amplitude B and harmonic component amplitude A can be obtained by analyzing the data through the control chip.

[0092] In this embodiment, in the FFT calculation result, the amplitude of the harmonic component (i.e., I0) is the amplitude of the harmonic component A in the original signal, while the amplitude of the DC component (i.e., the phase DC component current Ir) is 1 / 2 of the amplitude of the DC component B in the original signal.

[0093] The calculation methods for Ib' and Ic' are the same as above.

[0094] Calculate the phase DC component current Ir, and the corresponding phase resistance R = Ur / Ir. Assuming phase B is missing, then phases A and C are the operating phases. The calculated phase resistances are Ra and Rb. The hot resistance R2 can be either the larger one or the average of the two.

[0095] Obtaining the thermal resistance by superimposing the DC component can improve the efficiency and accuracy of acquisition.

[0096] In some embodiments, the step of calculating the stator winding temperature of the compressor based on thermal resistance includes:

[0097] Obtain the compressor's cold-state resistance and pre-operation temperature;

[0098] The stator winding temperature is calculated based on the cold resistance, the temperature before operation, and the hot resistance.

[0099] For rotor temperature T Magnet The temperature of the stator winding can be detected by resistance method. Before the motor runs, the cold resistance R1 of the stator winding is measured, and the temperature of the stator winding at this time is assumed to be the same as the current ambient temperature T1 (temperature before operation). R1 ​​and T1 are stored in advance, for example, stored in EEPROM (Electrically Erasable Programmable Read Only Memory).

[0100] It should be noted that the cold resistance R1 and the stator winding temperature T1 before operation can be stored permanently and do not need to be checked every time the motor is started.

[0101] Assuming the stator winding temperature rises to T2 after the motor starts running, and given that the resistance of a conductor changes with temperature, the stator winding resistance will rise to R2, which is the hot-state resistance. The relationship between the hot-state resistance and the cold-state resistance is R1 / R2 = (K + T1) / (K + T2), where K is the temperature coefficient of the winding material. For copper wire windings, K = 235°C; for aluminum wire windings, K = 220°C. T1 and T2 are expressed in degrees Celsius.

[0102] The stator windings and rotor magnets are on the same horizontal plane and very close to each other, so the stator winding temperature can be approximated as the rotor temperature. Even with some errors, the stator winding temperature is higher than the rotor temperature because the stator winding is the main heat source. Therefore, using the stator winding temperature as a protective variable is safe, and the error leads to a larger safety margin, further ensuring the safety of the compressor during single-phase operation.

[0103] Step S103: Determine the operating status of the compressor based on the demagnetizing current and peak current.

[0104] Specifically, based on the demagnetizing current I Demage and peak current I peak The current operating value is calculated; the operating status of the compressor is determined based on the current operating value.

[0105] The formula for calculating the current running value N is as follows:

[0106]

[0107] The compressor's operating status is determined based on the calculated current operating value N. The operating status includes safe status, frequency-limited status, temperature-limited status, and dangerous status. Specifically, the safe status is N < X1, indicating that the compressor is operating within the safe range; the frequency-limited status is X1 ≤ N < X2, indicating that the compressor is operating within the frequency-limited range; the temperature-limited status is X2 ≤ N < X3, indicating that the compressor is operating within the temperature-limited range; and the dangerous status is X3 ≤ N, indicating that the compressor is operating within the dangerous range.

[0108] For example, X1 is 0.6, X2 is 0.8, and X3 is 0.9.

[0109] It should be understood that the specific values ​​of X1, X2, and X3 can be set according to the actual situation.

[0110] This embodiment determines the compressor's operating status under phase loss conditions so that subsequent processing can be carried out accordingly, enabling more accurate phase loss protection.

[0111] Step S104: Control the compressor to execute the corresponding protection command according to the operating status.

[0112] Specifically, the compressor's current operating frequency is obtained; when the operating state is safe, the compressor is controlled to operate normally; when the operating state is frequency-limited, if the current operating frequency is greater than or equal to the preset frequency value, the current operating frequency is limited from increasing; if the current operating frequency is less than the preset frequency value, the current operating frequency is limited from decreasing; when the operating state is temperature-limited, if the current operating frequency is greater than or equal to the preset frequency value, the current operating frequency is decreased; if the current operating frequency is less than the preset frequency value, the current operating frequency is increased; when the operating state is dangerous, the compressor is shut down and a fault alarm signal is output.

[0113] When the air conditioner is turned on, during the operation of its compressor, the air conditioner detects the compressor's operating frequency in real time or at regular intervals to obtain the compressor's current operating frequency.

[0114] The preset frequency value is the critical value for dividing the low-frequency zone and the high-frequency zone. When the frequency is less than the preset frequency value, the frequency is in the low-frequency zone; when the frequency is greater than or equal to the preset frequency value, the frequency is in the high-frequency zone.

[0115] Different operating states correspond to different protection commands. When the operating state is safe, it means that the compressor is operating within a safe range, and the protection command is normal operation. The compressor can freely increase or decrease the frequency according to the control logic.

[0116] When the operating status is frequency limiting, determine whether the current operating frequency is in the high frequency range or the low frequency range. If it is in the high frequency range, the protection command is to limit the compressor from continuing to increase the frequency. If it is in the low frequency range, the protection command is to limit the compressor from continuing to decrease the frequency.

[0117] When the operating status is limited temperature, it determines whether the current operating frequency is in the high-frequency or low-frequency range. If it is in the high-frequency range, the protection command is for the compressor to actively reduce the frequency; if it is in the low-frequency range, the protection command is for the compressor to actively increase the frequency, which can increase the refrigerant flow and increase the heat dissipation capacity.

[0118] When the operating status is dangerous, it indicates that the compressor is operating in a dangerous range. It is considered that the compressor is close to the safety protection threshold, so the compressor is actively shut down and a fault alarm signal, i.e., a fault protection code, is output.

[0119] This embodiment determines the compressor's operating range by analyzing the above operating states and then executes corresponding protection commands, enabling more intelligent compressor phase loss protection. On one hand, compared to protection methods that shut down the compressor based on accumulated phase loss time, this method provides more analysis of the phase loss operating state, rather than simply assuming phase loss operation is dangerous and avoiding it altogether. On the other hand, compared to protection methods that rely on current magnitude to determine phase loss protection shutdown, this method effectively avoids the risk of overheating caused by low refrigerant flow when the compressor operates at low frequency and low current, providing stronger control over safe operation.

[0120] This application obtains the maximum current value among the three-phase currents of the compressor under phase-loss operation, and obtains the operating status based on the maximum current value and the compressor's demagnetizing current. Based on the operating status, the compressor is controlled to execute corresponding protection commands. This avoids the one-size-fits-all protection method under phase-loss operation, and can monitor and analyze key factors under phase-loss operation. This allows the compressor to be protected while maximizing its potential under phase-loss operation, enabling it to operate with faults within a safe range and reducing the probability of product failure and shutdown.

[0121] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0122] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by instructing related hardware through computer-readable instructions. These computer-readable instructions can be stored in a computer-readable storage medium. When executed, the program can include the processes of the embodiments of the above methods. The aforementioned storage medium can be a non-volatile storage medium such as a magnetic disk, optical disk, or read-only memory (ROM), or random access memory (RAM).

[0123] Further reference Figure 3 As a response to the above Figure 1 The implementation of the method shown in this application provides an embodiment of a compressor phase loss operation protection device, which is similar to... Figure 1 Corresponding to the method embodiments shown, this device can be specifically applied to various electronic devices.

[0124] like Figure 3 As shown, the compressor phase loss protection device 300 described in this embodiment includes: a detection module 301, an acquisition module 302, a status determination module 4303, and an execution protection module 4204. Wherein:

[0125] The detection module 301 is used to perform phase loss detection on the compressor at a preset time interval. If the compressor is detected to be in a phase loss operation state, the three-phase current of the compressor is obtained, and the peak current is obtained based on the three-phase current.

[0126] The acquisition module 302 is used to obtain the stator winding temperature of the compressor, use the stator winding temperature as the rotor temperature of the rotor which is in the same plane as the stator winding, and calculate the demagnetizing current based on the rotor temperature.

[0127] The status determination module 4303 is used to determine the operating status of the compressor based on the demagnetizing current and the peak current;

[0128] The protection execution module 304 is used to control the compressor to execute corresponding protection commands according to the operating status.

[0129] Based on the aforementioned compressor phase loss protection device, by acquiring the maximum current value among the three-phase currents of the compressor under phase loss operation, and obtaining the operating status based on the maximum current value and the compressor's demagnetizing current, the compressor can be controlled to execute corresponding protection commands according to the operating status. This avoids the one-size-fits-all protection method under phase loss operation, and can monitor and analyze key factors under phase loss operation. This not only protects the compressor but also maximizes the compressor's potential under phase loss operation, enabling it to operate with faults within a safe range and reducing the probability of product failure and shutdown.

[0130] In this embodiment, the detection module 301 includes an acquisition submodule, a current calculation submodule, and a selection submodule, wherein:

[0131] The acquisition submodule is used to acquire the voltage signals corresponding to the three components of the compressor through the sampling resistor;

[0132] The current calculation submodule is used to calculate the three-phase current based on the voltage signal using a frequency conversion control algorithm.

[0133] The selection submodule is used to select the maximum current value among the three-phase currents as the peak current.

[0134] The peak current is determined by calculating based on the collected voltage signal using a frequency conversion control algorithm. The calculation process is simple and can improve calculation efficiency.

[0135] In this embodiment, the acquisition module 302 includes a detection submodule and a temperature calculation submodule, wherein:

[0136] The detection submodule is used to detect the current hot resistance of the compressor;

[0137] The temperature calculation submodule is used to calculate the stator winding temperature of the compressor based on the thermal resistance;

[0138] In some optional implementations of this embodiment, the detection submodule is further used for:

[0139] By superimposing DC component voltages onto the original three-phase AC voltage of the compressor, the corresponding superimposed AC voltage is obtained.

[0140] The phase sampling current within a preset time period is generated based on the superimposed AC voltage;

[0141] Perform a Fourier transform on the sampled phase current to obtain the corresponding DC component current of the phase.

[0142] The current hot resistance is obtained based on the DC component voltage and DC component current.

[0143] Obtaining the thermal resistance by superimposing the DC component can improve the efficiency and accuracy of acquisition.

[0144] In this embodiment, the temperature calculation submodule is further used for:

[0145] Obtain the compressor's cold-state resistance and pre-operation temperature;

[0146] The stator winding temperature is calculated based on the cold resistance, the temperature before operation, and the hot resistance.

[0147] In some optional implementations, the state determination module 4303 includes a calculation submodule and a state determination submodule. The calculation submodule is used to calculate the current operating value based on the demagnetizing current and the peak current. The state determination submodule is used to determine the operating state of the compressor based on the current operating value. The operating state includes a safe state, a frequency limiting state, a temperature limiting state, and a dangerous state.

[0148] By judging the compressor's operating status under phase loss, we can take appropriate actions based on the operating status and perform phase loss protection more accurately.

[0149] In this embodiment, the protection execution module 304 is further configured to:

[0150] Obtain the current operating frequency of the compressor;

[0151] When the operating state is a safe state, the compressor is controlled to operate normally;

[0152] When the operating state is frequency limiting state, if the current operating frequency is greater than or equal to a preset frequency value, the current operating frequency is restricted from continuing to increase; if the current operating frequency is less than the preset frequency value, the current operating frequency is restricted from continuing to decrease.

[0153] When the operating state is a temperature-limited state, if the current operating frequency is greater than or equal to a preset frequency value, the current operating frequency is reduced; if the current operating frequency is less than the preset frequency value, the current operating frequency is increased.

[0154] When the operating state is dangerous, the compressor is shut down and a fault alarm signal is output.

[0155] By judging the above operating status, determining the range in which the compressor is operating, and then executing the corresponding protection command, the compressor phase loss protection can be performed relatively intelligently.

[0156] To address the aforementioned technical problems, embodiments of this application also provide a computer device. Please refer to [link / reference needed]. Figure 4 , Figure 4 This is a basic structural block diagram of the computer device in this embodiment.

[0157] The computer device 4 includes a memory 41, a processor 42, and a network interface 43 that are interconnected via a system bus. It should be noted that only the computer device 4 with components 41-43 is shown in the figure; however, it should be understood that it is not required to implement all the shown components, and more or fewer components can be implemented alternatively. Those skilled in the art will understand that the computer device described here is a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), embedded devices, etc.

[0158] The computer device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The computer device can interact with the user via a keyboard, mouse, remote control, touchpad, or voice control.

[0159] The memory 41 includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 41 may be an internal storage unit of the computer device 4, such as the hard disk or memory of the computer device 4. In other embodiments, the memory 41 may also be an external storage device of the computer device 4, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the computer device 4. Of course, the memory 41 may also include both the internal storage unit and its external storage device of the computer device 4. In this embodiment, the memory 41 is typically used to store the operating system and various application software installed on the computer device 4, such as computer-readable instructions for compressor phase loss protection methods. In addition, the memory 41 can also be used to temporarily store various types of data that have been output or will be output.

[0160] In some embodiments, the processor 42 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. The processor 42 is typically used to control the overall operation of the computer device 4. In this embodiment, the processor 42 is used to execute computer-readable instructions stored in the memory 41 or to process data, for example, to execute computer-readable instructions for the compressor phase loss protection method.

[0161] The network interface 43 may include a wireless network interface or a wired network interface, which is typically used to establish communication connections between the computer device 4 and other electronic devices.

[0162] This embodiment implements the steps of the compressor phase loss protection method described in the above embodiment by having the processor execute computer-readable instructions stored in the memory.

[0163] This application also provides another embodiment, namely, providing a computer-readable storage medium storing computer-readable instructions that can be executed by at least one processor to cause the at least one processor to perform the steps of the compressor phase loss operation protection method described above.

[0164] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0165] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A method for protecting a compressor from phase loss during operation, characterized in that, Includes the following steps: The compressor is subjected to phase loss detection at a preset time interval. If the compressor is detected to be in a phase loss operation state, the three-phase current of the compressor is obtained, and the peak current is obtained based on the three-phase current. The stator winding temperature of the compressor is obtained, and the stator winding temperature is used as the rotor temperature of the rotor that is in the same plane as the stator winding. The demagnetizing current is calculated based on the rotor temperature using a pre-fitted piecewise function, wherein the piecewise function is obtained by empirically fitting the relationship between the demagnetizing current of the compressor rotor magnet and the rotor temperature. The current operating value is calculated based on the demagnetizing current and the peak current; the operating state of the compressor is determined based on the current operating value; wherein, the operating state includes safe state, frequency limiting state, temperature limiting state, and dangerous state; The current operating frequency of the compressor is obtained, and the compressor is controlled to execute corresponding protection commands based on the operating status and the current operating frequency.

2. The compressor phase loss operation protection method according to claim 1, characterized in that, The step of obtaining the three-phase current of the compressor and obtaining the peak current based on the three-phase current includes: The voltage signals corresponding to the three compressor components are acquired by sampling resistors; Based on the voltage signal, the three-phase current is calculated using a frequency conversion control algorithm; The maximum current value among the three-phase currents is taken as the peak current.

3. The compressor phase loss operation protection method according to claim 1, characterized in that, The step of obtaining the stator winding temperature of the compressor includes: Detect the current thermal resistance of the compressor; The stator winding temperature of the compressor is calculated based on the thermal resistance.

4. The compressor phase loss operation protection method according to claim 3, characterized in that, The step of detecting the current hot resistance of the compressor includes: By superimposing DC component voltages onto the original three-phase AC voltage of the compressor, the corresponding superimposed AC voltage is obtained; Based on the superimposed AC voltage, a corresponding phase sampling current is generated within a preset time period; Perform a Fourier transform on the sampled phase current to obtain the corresponding DC component current of the phase. The current hot resistance is obtained based on the DC component voltage and the DC component current.

5. The compressor phase loss operation protection method according to claim 3, characterized in that, The step of calculating the stator winding temperature of the compressor based on the thermal resistance includes: Obtain the cold resistance and pre-operation temperature of the compressor; The stator winding temperature is calculated based on the cold resistance, the pre-operation temperature, and the hot resistance.

6. The compressor phase loss operation protection method according to claim 1, characterized in that, The step of controlling the compressor to execute corresponding protection commands based on the operating status and the current operating frequency includes: When the operating state is a safe state, the compressor is controlled to operate normally; When the operating state is frequency limiting state, if the current operating frequency is greater than or equal to a preset frequency value, the current operating frequency is restricted from continuing to increase; if the current operating frequency is less than the preset frequency value, the current operating frequency is restricted from continuing to decrease. When the operating state is a temperature-limited state, if the current operating frequency is greater than or equal to a preset frequency value, the current operating frequency is reduced; if the current operating frequency is less than the preset frequency value, the current operating frequency is increased. When the operating state is dangerous, the compressor is shut down and a fault alarm signal is output.

7. A compressor phase loss protection device, characterized in that, include: The detection module is used to perform phase loss detection on the compressor at preset time intervals. If the compressor is detected to be in a phase loss operation state, the module acquires the three-phase current of the compressor and obtains the peak current based on the three-phase current. The acquisition module is used to obtain the stator winding temperature of the compressor, take the stator winding temperature as the rotor temperature of the rotor that is in the same plane as the stator winding, and calculate the demagnetizing current based on the rotor temperature through a pre-fitted piecewise function, wherein the piecewise function is obtained by empirically fitting the relationship between the demagnetizing current of the compressor rotor magnet and the rotor temperature. A status determination module is used to determine the operating status of the compressor based on the demagnetizing current and the peak current. The status determination module includes a calculation submodule and a status determination submodule. The calculation submodule is used to calculate the current operating value based on the demagnetizing current and the peak current. The status determination submodule is used to determine the operating status of the compressor based on the current operating value. The operating status includes a safe status, a frequency limiting status, a temperature limiting status, and a dangerous status. The protection execution module is used to obtain the current operating frequency of the compressor and control the compressor to execute corresponding protection commands based on the operating status and the current operating frequency.

8. A computer device comprising a memory and a processor, wherein the memory stores computer-readable instructions, and the processor, when executing the computer-readable instructions, implements the steps of the compressor phase loss protection method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-readable instructions, which, when executed by a processor, implement the steps of the compressor phase loss operation protection method as described in any one of claims 1 to 6.

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