Compressor unit, control method thereof and computer readable storage medium

Abstract

The invention relates to a compressor unit, a control method of the compressor unit and a computer readable storage medium, and the control method comprises the steps that current values of all compressors during operation are obtained; obtaining a minimum current value according to all the current values; respectively selecting each compressor as a sample, and calculating the deviation value between the current value of the sample and the minimum current value; determining that the sample is normal according to the deviation value smaller than the preset deviation; determining that the sample is abnormal according to the deviation value greater than or equal to the preset deviation; and warning information is sent out and / or shutdown is carried out according to sample abnormity. According to the control method of the compressor unit, the current deviation of the compressor is monitored in real time and compared with the minimum current value, the preset deviation threshold value is dynamically adjusted in combination with the load rate, accurate recognition of the abnormal state is achieved, it can be effectively avoided that early faults are evolved into serious accidents, and the system operation stability and maintenance efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioning equipment, in particular to a compressor unit, a control method thereof and a computer readable storage medium. BACKGROUND

[0002] In order to obtain greater whole machine cooling capacity and simplify the pipeline and control cost, a mainstream scheme of parallel connection of multiple compressors is adopted, and the multiple compressors are connected through an oil balance pipe. Since the starting current of a fixed frequency compressor is large, the compressors are basically started one by one in an interval in a starting stage. The compressors started later are in a relatively poor state in terms of lubricating oil amount, high and low pressure load and power grid voltage. Therefore, the multiple compressors actually connected in parallel are not the same in terms of wear and loss in long-term use.

[0003] Although the compressor maximum running current protection is set in the whole machine according to the compressor specification book, after long-term wear and tear of the moving parts of the compressor and aging of the motor winding insulation, the iron filings generated by the wear and tear fall on the motor winding. In some high load working conditions, the current of the compressor will instantaneously increase, and the motor winding will be burned out. During this period, the control logic and hardware protection cannot act in time, and at the same time, the refrigerant flow path of the parallel connected compressors is polluted, and the contactor of the compressor is stuck by fire, which brings great trouble to the later maintenance. SUMMARY

[0004] The present application aims at at least solving the problem that the abnormality of part of the compressors in the parallel connected compressor unit affects other compressors. The aim is achieved in the following manner: The first aspect of the present application provides a control method of a compressor, the compressor unit comprising multiple compressors connected in parallel in a refrigerant flow path, the control method comprising: acquiring current values of the multiple compressors when the multiple compressors are running; acquiring a minimum current value from all the current values as a minimum current value; selecting each of the multiple compressors as a sample respectively, and calculating a deviation value of the current value of the sample from the minimum current value; determining that the sample is normal according to that the deviation value is less than a preset deviation; determining that the sample is abnormal according to that the deviation value is greater than or equal to the preset deviation; and issuing a warning information and / or stopping according to that the sample is abnormal.

[0005] According to the control method of the compressor unit of the present application, the deviation of the current of the compressor is monitored in real time and compared with the minimum current value, and the preset deviation threshold is dynamically adjusted in combination with the load rate, so that the abnormal state is accurately identified, early failure is effectively avoided from evolving into a serious accident, and the system operation stability and maintenance efficiency are improved.

[0006] In addition, the control method of the compressor unit according to the present application can also have the following additional technical features: In some embodiments of the present application, the step of calculating the deviation value of the current value of the sample from the minimum current value comprises: calculating the difference I i between the current value of the sample and the minimum current value I o ; i I o i , dividing the difference I o by the minimum current value I o to obtain (I i -I o ) / I o as the deviation value; wherein the preset deviation is any value between 10% and 50%.

[0007] In some embodiments of the present application, before the step of determining that the sample is normal according to the deviation value being less than a preset deviation, the method further comprises: obtaining a load rate of the sample; determining that the value range of the preset deviation is 20% to 50% according to the load rate being less than 50%; determining that the value range of the preset deviation is 10% to 20% according to the load rate being greater than or equal to 50%.

[0008] In some embodiments of the present application, before the step of obtaining the current value of each compressor during operation, the method further comprises: obtaining the start-up duration of the compressor set; and performing the step of obtaining the current value of each compressor during operation according to the start-up duration being greater than a preset duration.

[0009] In some embodiments of the present application, the step of issuing a warning information and / or stopping according to the sample being abnormal comprises: obtaining the determination result of the same sample multiple times at a preset time interval within a first time period, and recording the number of times that the sample is normal and the number of times that the sample is abnormal; calculating the abnormal percentage of the number of times that the sample is abnormal in the total number of determination results; and issuing a warning information and / or stopping according to the abnormal percentage being greater than or equal to a preset proportion.

[0010] In some embodiments of the present application, the compressor is a variable frequency compressor, and the step of issuing a warning information and / or stopping according to the sample being abnormal comprises: issuing a warning information according to the sample being abnormal; and controlling the sample to reduce the operating frequency until the deviation value of the current value of the sample from the minimum current value is less than the preset deviation.

[0011] In some embodiments of the present application, the step of controlling the sample to reduce the operating frequency until the deviation value of the current value of the sample from the minimum current value is less than the preset deviation comprises: controlling the operating frequency of the sample to decrease by a first value for a first duration; ​acquiring a real-time current value of the sample, and calculating a real-time deviation value of the real-time current value and the minimum current value; controlling the sample to keep a current operating frequency according to the real-time deviation value being less than a preset deviation; controlling the operating frequency of the sample to continue to decrease by a second value and for the first time length according to the real-time deviation value being greater than or equal to the preset deviation, the second value being less than the first value; returning to the step of acquiring the real-time current value of the sample.

[0012] In some embodiments of the present application, the control method further comprises: selecting each of the compressors as a sample respectively, and determining whether the current value of the sample is greater than or equal to a maximum current threshold; and performing current overload protection according to the current value of any of the samples being greater than the maximum current threshold.

[0013] In some embodiments of the present application, after the step of determining that the sample is normal according to the deviation value being less than a preset deviation, the control method further comprises: acquiring an accumulated operating time length of each of the compressors; acquiring current value data of each of the compressors within the accumulated operating time length; calculating a growth slope of the current value of each of the compressors with the growth of the accumulated operating time length under the same working condition according to the accumulated operating time length and the current value data; acquiring a minimum growth slope from all the growth slopes as a minimum growth slope value; selecting each of the compressors as a sample respectively, and calculating a slope ratio value of the growth slope of the sample and the minimum growth slope value; and issuing a warning information according to the slope ratio value being greater than or equal to a preset ratio value.

[0014] In some embodiments of the present application, the preset ratio value ranges from 1.01 to 1.5.

[0015] The second aspect of the present application further proposes a compressor unit capable of performing the control method of any one of the first aspect, and the compressor unit comprises: a plurality of compressors connected in parallel in a refrigerant flow path; and a control device electrically connected to each of the compressors respectively.

[0016] The second aspect of the present application further proposes a computer readable storage medium having a computer program stored thereon, and the computer program, when executed by a processor, implements the control method of the compressor unit of any one of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings. The drawings are for purposes of illustration only and are not intended to limit the present application thereto, as the present application can have additional forms that will become apparent to those of ordinary skill in the art upon reading this description. In the drawings, like reference numerals indicate like elements through the several views. Among other things: Figure 1 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 2 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 3 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 4 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 5 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 6 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 7 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 8 Flowchart of a control method of a compressor unit according to an embodiment of the present application; Figure 9 Structure diagram of a compressor unit according to an embodiment of the present application; Figure 10 Electrical connection diagram of a control device and compressors in a compressor unit according to an embodiment of the present application.

[0018] The reference numerals in the drawings indicate the following: 100: compressor unit; 10: compressor; 20: refrigerant flow path; 200: control device; 2002: memory; 2001: processor. DETAILED DESCRIPTION

[0019] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms without being limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0020] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0021] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure rotates, then an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.

[0024] An embodiment of the present invention provides a control method for a compressor unit, such as... Figure 1 As shown, the compressor unit includes multiple compressors connected in parallel in the refrigerant flow path, and the control method includes the following steps: Step S101: Obtain the current value of each compressor during operation; Step S102: Obtain the minimum current value based on all current values; Step S103: Select each compressor as a sample and calculate the deviation between the sample current value and the minimum current value; Step S104: Determine the sample is normal based on the deviation value being less than the preset deviation; Step S105: Determine the sample as abnormal based on the deviation value being greater than or equal to the preset deviation; Step S106: Issue a warning message and / or shut down the system based on sample anomalies.

[0025] In step S101, obtaining the current value of each compressor during operation means extracting real-time current data from the compressor's current sensor or monitoring device. The current signal can be directly acquired by hardware circuitry and converted into a digital signal, or the received analog signal can be processed by software algorithm to obtain the current value, so as to realize real-time monitoring of the compressor's operating status.

[0026] In step S102, the minimum current value is obtained based on all current values. By comparing all current values, the minimum value is selected one by one from all current values. The purpose of obtaining the minimum current value is to establish a benchmark value for subsequent deviation calculation.

[0027] In step S103, the deviation between the current value of the sample and the minimum current value can be calculated by absolute difference, such as by subtracting the minimum current value from the sample current value and taking the absolute value, or by relative difference, such as by taking the difference between the ratio of the sample current value to the minimum current value and 1 as the deviation value. This is mainly to quantify the degree of difference between the sample and the benchmark.

[0028] In steps S104 and S105, the preset deviation is a pre-set fixed threshold. The deviation value is compared with the preset deviation. When the deviation value is less than the preset deviation, it indicates that the current value of the sample is within the normal range, and the sample is determined to be normal, ensuring the stable operation of the system within a reasonable range. Conversely, if the deviation value is greater than or equal to the preset deviation, it is determined that due to the accumulation of wear on moving parts, aging of motor winding insulation, etc., the sample has a higher current value than other compressors under the same operating conditions, and it is necessary to prevent the sample from burning out under high load conditions.

[0029] In this embodiment, the operating current values ​​of multiple parallel compressors are monitored in real time to obtain current data of each compressor under actual working conditions, thus providing a basis for subsequent analysis. Further, based on all the obtained current values, the minimum current value is determined and used as a benchmark value to reflect the operating level of the compressor with the least wear under the current condition. Specifically, each compressor is selected as a sample, and the deviation between its current value and the minimum current value is calculated, thereby achieving a quantitative comparison of the current state of each compressor. When the deviation value is less than a preset deviation, the sample is determined to be in a normal state, ensuring stable operation of the system within a reasonable fluctuation range; when the deviation value is greater than or equal to the preset deviation, the sample is determined to be in an abnormal state, thus accurately identifying compressors with abnormal current due to increased wear. Based on this, warning information and / or shutdown operations are issued according to the abnormal sample results, promptly interrupting the fault development path and preventing motor winding burnout accidents and refrigerant flow path contamination caused by a sudden increase in current. This effectively solves the problem of abnormal current caused by uneven wear of multiple parallel compressors during long-term use, thereby achieving safe protection and stable operation of the compressor unit.

[0030] In some embodiments, the step of calculating the deviation between the sample current value and the minimum current value includes: calculating the difference Ii between the sample current value Ii and the minimum current value Io. i -Io is calculated by dividing the difference by the minimum current value to obtain the deviation value (Ii-Io) / Io; where the preset deviation is any value between 10% and 50%. In this embodiment, the preset deviation is set to 15%.

[0031] Specifically, the deviation value refers to the result obtained through the relative deviation calculation method. In practical applications, the deviation value (Ii-Io) provides the difference between the sample current and the reference current, but the magnitude of this difference is directly affected by the current level and cannot directly reflect the degree of abnormality. Therefore, by dividing the deviation value by the minimum current value Io, the absolute difference can be converted into a relative percentage form, so that the deviation value no longer depends on the absolute magnitude of the current, thus improving the accuracy of the state judgment.

[0032] In this embodiment, by introducing a relative deviation calculation method, the problem of poor adaptability of the deviation threshold under different operating conditions is effectively solved. First, the deviation (Ii-Io) between the sample current value Ii and the minimum current value Io is calculated, providing basic data for subsequent analysis. Then, the deviation value is divided by the minimum current value Io to obtain the deviation value (Ii-Io) / Io, thereby converting the relative difference into a relative percentage form. This ensures that the deviation value can accurately determine the operating status of the sample compressor under various load conditions, avoiding misjudgment caused by changes in current level. In addition, the preset deviation range of 10% to 50% is set based on actual operating data, which can effectively capture abnormal states while covering the normal current fluctuation range.

[0033] In some embodiments, such as Figure 2 As shown, before the step of determining that the sample is normal based on the deviation value being less than the preset deviation, the following steps are also included: Step S201: Obtain the sample load rate; Step S202: Based on the load rate being less than 50%, determine the preset deviation range to be 20% to 50%; Step S203: Based on the load rate being greater than or equal to 50%, determine the range of the preset deviation to be 10% to 20%.

[0034] Specifically, the load rate of the sample is obtained as a quantitative basis for estimating the current operating load state of the compressor through sensors or algorithms. This can be achieved using methods such as current detection, power calculation, or pressure difference measurement. In this embodiment, the compressor load rate is obtained through the current value I... i / Maximum current threshold I max Calculated maximum current threshold I max This is the maximum operating current specified in the compressor product specifications. When the compressor's current exceeds the maximum operating current, overload protection will be activated to shut it down.

[0035] According to the load factor (I) i / I max For loads less than 50%, the preset deviation range is set to 20% to 50%. This aims to set a wider deviation range for current fluctuations under low load conditions, thereby avoiding misjudgment of current changes during normal operation. For loads greater than or equal to 50%, the preset deviation range is set to 10% to 20%. This aims to focus on fault sensitivity under high load conditions, setting a narrower deviation range to more sensitively detect abnormal current increases.

[0036] In detail, in this embodiment, the system first obtains the load rate of the sample to provide a sense of the compressor's current operating environment. The preset deviation range is dynamically adjusted based on the load rate, enabling the anomaly detection mechanism to adapt to different operating conditions. When the load rate is below 50%, the system determines that the compressor is operating under partial load, allowing for a larger current fluctuation range. Therefore, the preset deviation range is set to 20% to 50%, effectively accommodating normal fluctuations and reducing unnecessary warnings or shutdowns. When the load rate reaches or exceeds 50%, the system determines that the compressor is approaching its design operating condition, requiring a highly stable current value. Therefore, the preset deviation range is reduced to 10% to 20% to promptly identify potential wear or insulation aging risks. This setting not only solves the problem of a fixed range being unable to adapt to changes in operating conditions but also significantly improves the accuracy of fault detection and system reliability.

[0037] In some embodiments, such as Figure 3 As shown, the step of obtaining the current value of each compressor during operation also includes: Step S301: Obtain the start-up duration of the compressor unit; Step S302: If the start-up time is longer than the preset time, execute the step of obtaining the current value of each compressor during operation.

[0038] Specifically, the start-up time refers to the time interval from the start of the compressor to the current moment, which can be achieved through a timer or system clock. The purpose of obtaining the start-up time is to ensure that current monitoring is only performed after the system has entered a stable state, thereby avoiding false alarms. The preset time can be a fixed time threshold set based on experimental data or equipment characteristics to avoid the unstable state during the compressor start-up transition phase. In this case, the preset time is set to 5 minutes.

[0039] In this embodiment, by using the start-up duration as a prerequisite trigger condition, the risk of misjudgment due to system instability during the startup phase is effectively avoided. In practical applications, the compressor needs to go through an inherent transition period from startup to stable operation, during which current fluctuations occur. By tracking the start-up duration in real time, it is possible to objectively quantify whether the system has escaped transient operating conditions. The current value acquisition step is only executed when the start-up duration exceeds the preset duration, distinguishing between normal startup current fluctuations and actual fault characteristics, thereby improving the accuracy of fault diagnosis.

[0040] It should also be noted that by introducing the start-up duration judgment, not only is the timing of current monitoring optimized, but the continuity and reliability of system operation are further enhanced, and the problem of false alarms caused by drastic current fluctuations in the early stage of startup is specifically solved.

[0041] In some embodiments, such as Figure 4As shown, issuing warning messages and / or shutting down the system based on sample anomalies includes the following steps: Step S401: Within the first time period, obtain the judgment result of the same sample multiple times at preset time step intervals, and record the number of times the sample is normal and the number of times it is abnormal. Step S402: Calculate the percentage of abnormal occurrences out of all judgment results; Step S403: Issue a warning message and / or shut down the machine if the percentage of abnormalities is greater than or equal to a preset percentage.

[0042] Specifically, the first time period refers to a fixed time window set by the system, which can be adjusted according to actual working conditions. For example, the first time period can be set to 5 minutes or 10 minutes. The preset time step interval can be uniformly distributed time points or non-uniformly distributed time series with specific patterns, ensuring that the sampled data can comprehensively reflect the actual operating status of the samples. The anomaly percentage is the ratio of the number of anomalies to the total number of samples within the statistical period. This indicator can effectively quantify the frequency of anomalies.

[0043] In this embodiment, the compressor sample current value is first collected by sampling multiple times within a fixed time window to determine if it is abnormal, and the number of normal and abnormal occurrences is recorded. This repeated detection method within a certain time period captures the continuous characteristics of anomalies, thus avoiding the influence of instantaneous factors such as power grid fluctuations or load changes on single measurements. Subsequently, the number of anomalies is converted into a percentage of the total number of samples, allowing the judgment standard to move beyond the limitations of absolute numbers and adapt to sampling densities under different operating conditions. Finally, the system triggers an alarm message and / or shutdown operation only when the percentage of anomalies reaches or exceeds a preset proportion. This setting ensures that a response is triggered only when an anomaly persists to a certain extent, effectively filtering instantaneous interference and avoiding malfunctions caused by occasional interference. This not only improves system stability but also significantly reduces the false alarm rate caused by instantaneous current fluctuations or occasional interference, thereby ensuring the continuity and reliability of the compressor unit's operation.

[0044] In some embodiments, such as Figure 5 As shown, when the compressor is a variable frequency compressor, the steps for issuing warning messages and / or shutting down the machine based on sample anomalies include: Step S501: Issue a warning message based on sample anomalies; Step S502: Control the sample to reduce the operating frequency until the deviation between the sample current value and the minimum current value is less than the preset deviation.

[0045] Specifically, a variable frequency compressor refers to a compressor that changes the motor speed by adjusting the frequency of the input power supply. Variable frequency compressors can dynamically adjust their operating frequency according to load demand, thereby optimizing energy consumption and extending equipment life. Controlling the compressor reduces the operating frequency to avoid system interruptions due to direct shutdown, while simultaneously using frequency adjustment to bring the current back to the normal range.

[0046] In this embodiment, the system maintains continuous operation and protects equipment by dynamically adjusting the operating frequency to cope with abnormal situations. First, when the deviation between the sample current value and the minimum current value exceeds a preset deviation, the system issues a warning message to provide operators with response time and prevent unnecessary shutdowns due to misjudgment or temporary overload. Subsequently, the system controls the sample to reduce its operating frequency, gradually decreasing the load and dynamically responding to overload conditions using the frequency converter's characteristics until the current value returns to the normal range. This closed-loop adjustment, combined with real-time deviation monitoring, ensures the targeted and effective frequency reduction, avoids the interference of indiscriminate shutdowns on overall operation, effectively prevents the risk of motor burnout, and guarantees continuous power supply to the system.

[0047] In some embodiments, such as Figure 6 As shown, the steps to control the sample to reduce its operating frequency until the deviation between the sample's current value and the minimum current value is less than a preset deviation include: Step S601: Control the sample running frequency to decrease the first value and continue for a first duration; Step S602: Obtain the real-time current value of the sample and calculate the real-time deviation between the real-time current value of the sample and the minimum current value; Step S603: Based on the real-time deviation value being less than the preset deviation, control the sample to maintain the current operating frequency; Step S604: Based on the real-time deviation value being greater than or equal to the preset deviation, control the sample's running frequency to continue decreasing the second value for a first duration, and return to the step of obtaining the sample's real-time current value.

[0048] Specifically, the first value is the larger frequency adjustment step size used in the initial stage for rapid response to abnormal states. It can be set to a fixed value or an adjustable parameter depending on the specific model and operating conditions of the compressor unit. In practical applications, the first value can be determined using empirical values, experimental data, or adaptive algorithms, with the aim of rapidly approaching the target frequency while avoiding system shock. The first duration refers to the time interval maintained after each frequency adjustment, ensuring the system has sufficient time to adapt to frequency changes and avoiding operational oscillations caused by excessively rapid adjustments. The second value refers to the smaller frequency adjustment step size used in the subsequent fine-tuning stage. The second value is a certain proportion of the first value. In this embodiment, the ratio of the second value b to the first value a, b / a, ranges from 0.5 to 0.9 to achieve finer frequency control and eliminate residual deviations.

[0049] In this embodiment, firstly, by reducing a first value and maintaining it for a first duration, a rapid response to abnormal states is achieved, while simultaneously preventing frequency abrupt changes from impacting the system. Subsequently, by acquiring the current value of the sample in real time and calculating the real-time deviation value, a dynamic feedback mechanism is formed, ensuring that adjustment decisions closely align with the current operating conditions. When the real-time deviation value is less than a preset deviation, the system automatically maintains the current operating frequency, avoiding efficiency losses caused by over-adjustment. If the real-time deviation value is still greater than or equal to the preset deviation, a smaller second value is used for fine-tuning. Through a step-by-step convergence adjustment method, energy efficiency deterioration caused by excessive frequency reduction is prevented, while ensuring the precise elimination of minor deviations. This solution effectively addresses the sample anomaly problem while ensuring safe system operation and maximizing operational efficiency.

[0050] In some embodiments, such as Figure 7 As shown, the control method includes the following steps: Step S701: Obtain the current value of each compressor during operation; Step S702: Obtain the minimum current value from all current values ​​as the minimum current value; Step S703: Select each compressor as a sample and determine whether the current value of the sample is greater than or equal to the maximum current threshold. Step S704: Execute overcurrent protection based on the current value of any sample being greater than or equal to the maximum current threshold. Step S705: Based on the fact that the current values ​​of all samples are less than the maximum current threshold, calculate the deviation between the current values ​​of the samples and the minimum current values. Step S706: Determine the sample is normal based on the deviation value being less than the preset deviation; Step S707: Determine the sample as abnormal based on the deviation value being greater than or equal to the preset deviation; Step S708: Issue a warning message and / or shut down the system based on sample anomalies.

[0051] In this embodiment, step S701 is the same as step S101, step S702 is the same as step S102, and steps S705 to S708 are the same as steps S103 to S106, which will not be described again here.

[0052] In steps S703 and S704, determining whether the sample current value is greater than or equal to the maximum current threshold can be achieved through a real-time monitoring circuit. For example, a current transformer or Hall effect sensor can be used to detect the current signal, and the measured current value can be compared with a preset maximum current threshold. Maximum current threshold I maxThis refers to the maximum operating current, or rated current value, set in the compressor product specifications. For example, the maximum current threshold can be a fixed value between 120% and 150% of the rated current to ensure safe operation. In this embodiment, the maximum current threshold I... max Set to 85A.

[0053] In detail, by introducing a real-time monitoring mechanism for absolute current values, the original anomaly detection system based on relative deviation is effectively supplemented. First, each compressor is selected as a sample, and its current value is checked against the maximum current threshold. The real-time current level of each compressor is then assessed based on this fixed threshold. Second, the overload condition is determined by directly comparing the real-time current value with the maximum current threshold. This allows for immediate identification of potential overload risks when the current spikes instantaneously, without waiting for deviation calculations. Finally, upon detecting an overload, a protection mechanism, such as shutdown or warning, is immediately activated, ensuring immediate response and effectively preventing continuous damage to the motor from high current. This also prevents winding burnout and refrigerant flow path contamination caused by protection delays.

[0054] In some embodiments, such as Figure 8 As shown, after determining that the sample is normal based on the deviation value being less than the preset deviation, the control method also includes the following steps: Step S801: Obtain the cumulative runtime of each compressor; Step S802: Obtain the current value data of each compressor during the cumulative running time; Step S803: Based on the cumulative running time and current value data, calculate the slope of the current value of each compressor as the cumulative running time increases under the same operating conditions; Step S804: Obtain the minimum growth slope from all growth slopes as the minimum growth slope value, select each compressor as a sample, and calculate the ratio of the sample's growth slope to the minimum growth slope value. Step S805: Issue a warning message if the slope ratio is greater than or equal to a preset ratio.

[0055] The preset ratio ranges from 1.01 to 1.5.

[0056] In this embodiment, the cumulative runtime is the total operating time of the compressor from its initial use to the current moment, which can be recorded using a built-in timer or external monitoring equipment. Current value data is a set of compressor current values ​​collected at different time points, monitored in real-time by sensors and stored in a database to capture long-term trends in electrical characteristics. The growth slope refers to the rate of change of the current value with cumulative runtime under the same operating conditions. The minimum growth slope value represents a reference benchmark for the slightest wear state among all compressors, aiming to provide a reliable reference point for lateral comparison. The slope ratio refers to the proportional relationship between the growth slope of each compressor and the minimum growth slope value. The magnitude of the slope ratio can relativize the degree of degradation of some compressors, accurately identifying individuals with abnormally accelerated wear. The preset ratio range is set to 1.01 to 1.5, aiming to balance the sensitivity of early warning with system stability and avoid false alarms due to minor fluctuations.

[0057] In this embodiment, a mapping framework between compressor operating time and current value is first established by acquiring cumulative running time and current value data. By analyzing the gradual increase in compressor current with increasing operating time under the same operating conditions, the gradual impact of wear on compressor moving parts and insulation aging on current is indirectly obtained, thus compensating for the inability to monitor long-term wear trends by relying solely on real-time data. Subsequently, based on the current growth slope calculation under the same operating conditions, the fairness of data under consistent load is ensured, avoiding interference from operating condition fluctuations on the judgment of degradation trends. On this basis, by introducing the minimum growth slope value as a benchmark, a horizontal comparison of the wear state of each compressor is realized. Furthermore, by calculating the slope ratio and comparing it with a preset ratio, an early warning mechanism can be triggered before the problem worsens, thereby effectively preventing sudden failures caused by long-term wear accumulation. In addition, the above scheme, combined with the aforementioned anomaly detection method based on real-time current deviation, forms a multi-layered protection mechanism that considers both real-time status and long-term trends, significantly improving the reliability and safety of the system. It can not only identify potential risks in advance, but also trigger an early warning mechanism before the problem worsens, thereby effectively preventing sudden failures caused by long-term wear and tear.

[0058] According to an embodiment of the present invention, a compressor unit 100 is also provided, such as Figure 9 and Figure 10 As shown, the compressor unit 100 is capable of executing the above-described control method. The compressor unit 100 includes multiple compressors 10 and a control device 200. The multiple compressors 10 are connected in parallel in the refrigerant flow path 20. The control device 200 is electrically connected to each compressor 10. The control device 200 obtains the operating information of each compressor 10 through the electrical connection. The control device 200 extracts real-time current data from the current sensor or monitoring device of the compressor 10, or processes the received analog signal through software algorithms to obtain the current value, thereby achieving real-time monitoring of the operating status of the compressor 10. Further, the control device 200 obtains the minimum current value based on all current values ​​and calculates the deviation between the sample current value and the minimum current value. The control device 200 determines that the sample is normal if the deviation is less than a preset deviation, ensuring stable system operation within a reasonable range. When the deviation is greater than or equal to the preset deviation, the control device 200 controls the compressor unit 100 to stop, or controls the compressor unit 100 to issue a warning message. This effectively solves the problem of abnormal current caused by uneven wear during long-term use of multiple parallel compressors 10, thus achieving safe protection and stable operation of the compressor unit 100.

[0059] In this embodiment, as Figure 10 As shown, the control device 200 includes a memory 2002 and at least one processor 2001, wherein the memory 2002 stores a program or instructions that can be executed on the processor 2001, and the processor 2001 executes the program or instructions to implement the steps of the compressor unit control method in this application.

[0060] According to embodiments of the present invention, a computer storage medium is also provided, on which computer-readable instructions are stored. When executed by one or more processors, the computer-readable instructions cause the one or more processors to perform the control method of the compressor unit in any embodiment of the present invention. The control method may include, but is not limited to, at least one of the following steps: acquiring the current value of each compressor during operation; acquiring the minimum current value based on all current values; selecting each compressor as a sample and calculating the deviation between the current value of the sample and the minimum current value; determining that the sample is normal if the deviation value is less than a preset deviation; determining that the sample is abnormal if the deviation value is greater than or equal to the preset deviation; issuing a warning message and / or stopping the compressor based on the abnormal sample.

[0061] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable storage medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable storage media include: electrical connections (electronic devices) having one or more wires, portable computer disks (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM, or flash memory), fiber optic devices, and compact disc read-only memory (CDROM). Furthermore, computer-readable storage media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0062] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0063] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method of a compressor unit, characterized by, The compressor unit comprises a plurality of compressors connected in parallel in a refrigerant flow path, and the control method comprises: obtaining current values of each compressor in operation; obtaining the minimum current value from all current values as the minimum current value; selecting each compressor as a sample respectively, and calculating the deviation value of the current value of the sample and the minimum current value; determining that the sample is normal according to the deviation value being less than a preset deviation; determining that the sample is abnormal according to the deviation value being greater than or equal to the preset deviation; issuing a warning information and / or stopping according to the sample being abnormal.

2. The control method of a compressor unit according to claim 1, characterized by, The step of calculating the deviation value of the current value of the sample and the minimum current value comprises: calculating a current value I of the sample i the difference I o -I i o , from the difference I i -I o divided by the minimum current value I o (I i -I o ) / I o as the deviation value;​ wherein the preset deviation takes any value in the range of 10% to 50%.

3. The control method of a compressor unit according to claim 2, characterized by, Before the step of determining that the sample is normal according to the deviation value being less than a preset deviation, the method further comprises: obtaining the load rate of the sample; determining that the value range of the preset deviation is 20% to 50% according to the load rate being less than 50%; determining that the value range of the preset deviation is 10% to 20% according to the load rate being greater than or equal to 50%.

4. The control method of a compressor unit according to claim 1, characterized by, Before the step of obtaining the current values of each compressor in operation, the method further comprises: obtaining the start-up time length of the compressor unit; performing the step of obtaining the current values of each compressor in operation according to the start-up time length being greater than a preset time length.

5. The control method of the compressor unit according to claim 4, wherein The step of issuing a warning information and / or stopping according to the sample being abnormal comprises: in a first time period, obtaining the determination result of the same sample multiple times at a preset time step interval, and recording the number of times of normal and abnormal of the sample; calculating the abnormal percentage of the number of times of abnormal in the total number of determination results; issuing a warning information and / or stopping according to the abnormal percentage being greater than or equal to a preset percentage.

6. The control method of a compressor unit according to any one of claims 1 to 5, characterized by, The compressor is a variable frequency compressor, and the step of issuing a warning information and / or stopping according to the sample being abnormal comprises: issuing a warning information according to the sample being abnormal; controlling the sample to reduce the operating frequency until the deviation value of the current value of the sample and the minimum current value is less than the preset deviation.

7. The control method of a compressor unit according to claim 6, characterized by The step of controlling the sample to reduce the operating frequency until the deviation value of the current value of the sample and the minimum current value is less than the preset deviation comprises: controlling the operating frequency of the sample to decrease by a first value for a first time length; obtaining the real-time current value of the sample, and calculating the real-time deviation value of the real-time current value and the minimum current value; controlling the sample to keep the current operating frequency according to the real-time deviation value being less than a preset deviation; controlling the operating frequency of the sample to continue to decrease by a second value for the first time length according to the real-time deviation value being greater than or equal to the preset deviation, the second value being less than the first value; returning to perform the step of obtaining the real-time current value of the sample.

8. The control method of a compressor unit according to any one of claims 1 to 5, characterized by, The control method further comprises: selecting each compressor as a sample respectively, and determining whether the current value of the sample is greater than or equal to a maximum current threshold value; The current overload protection is performed according to the current value of any sample being greater than or equal to the maximum current threshold.

9. The control method of a compressor unit according to any one of claims 1 to 5, characterized by, After the step of determining that the sample is normal according to the deviation value being less than the preset deviation, the control method further comprises: acquiring an accumulated running time length of each of the compressors; acquiring current value data of each of the compressors within the accumulated running time length; calculating, according to the accumulated running time length and the current value data, a growth slope of the current value of each of the compressors with the increase of the accumulated running time length under the same working condition; acquiring, from all the growth slopes, a minimum growth slope as a minimum growth slope value; selecting each of the compressors as a sample respectively, and calculating a slope ratio value of the growth slope of the sample and the minimum growth slope value; issuing a warning information according to the slope ratio value being greater than or equal to the preset ratio value.

10. The control method of a compressor unit according to claim 9, characterized by, The preset ratio value ranges from 1.01 to 1.

5.

11. A compressor unit capable of performing the control method according to any one of claims 1 to 10, characterized by The compressor unit comprises: a plurality of compressors connected in parallel in a refrigerant flow path; a control device electrically connected to each of the compressors.

12. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by a processor, implements the control method of the compressor unit according to any one of claims 1-10.

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