An automatic control method for an air compressor, a control system and an air compressor

Abstract

The present invention discloses an automatic control method, a control system and an air compressor, comprising: after the motor is started, periodically obtaining the real-time pressure value of the air storage tank and the corresponding real-time pressure increase rate. Comparing the magnitudes of the real-time pressure increase rate and the target pressure increase rate, if the real-time pressure increase rate is less than the target pressure increase rate, then according to the motor temperature, the room temperature and the motor temperature rise curve, determining whether the power of the motor can be increased, and if the power of the motor cannot be increased, then sending out a fault prompt. If the real-time pressure increase rate is greater than the target pressure increase rate, then reducing the power of the motor. By monitoring the real-time pressure increase rate of the air storage tank in real time, the actual air collection effect of the air compressor is monitored, so as to timely adjust the working state of the motor, realize the closed-loop control of the air compressor, effectively protect the motor and improve the service life of the air compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of air compressors, and in particular, to an automatic control method for an air compressor, a control system, and an air compressor. Background Art

[0002] An air compressor, abbreviated as an air compressor, is a device commonly used to collect and supply compressed air to a pneumatic system. The current commonly used portable air compressor control system is simple, for example, it only has functions such as pressure regulation and automatic start and stop. However, during daily use, due to reasons such as untimely maintenance, the air compressor may malfunction and cannot work properly. For example, the commonly used piston air compressors on the market mostly use thin steel sheets to seal the air holes in the piston. The thin steel sheets will be damaged due to metal fatigue and other reasons during long-term use, resulting in the air compressor being unable to collect air normally. However, the current air compressor control system is not intelligent enough. When the air compressor cannot collect air normally, it cannot timely adjust the power of the motor to meet the air supply demand, nor can it give a fault alarm to prompt the user that the air compressor has a fault. Summary of the Invention

[0003] In order to solve the problems that the air compressor control system cannot adjust the working state of the motor according to the actual air supply situation of the air compressor and cannot give a fault alarm, the present application provides an automatic control method for an air compressor, including the following steps: S1: After the motor is started, periodically obtain the real-time pressure value of the air storage tank and the corresponding real-time pressure increase rate; S2: Calculate the first absolute difference between the real-time pressure increase rate and the target pressure increase rate corresponding to the same pressure value; S3: Compare the first absolute difference with a first threshold. If the first absolute difference is greater than the first threshold, then compare the magnitudes of the real-time pressure increase rate and the target pressure increase rate; S4: If the real-time pressure increase rate is less than the target pressure increase rate, then at least based on the motor temperature, room temperature, and the motor temperature rise curve, determine whether the power of the motor can be increased. If the power of the motor cannot be increased, then issue a fault prompt; S5: If the real-time pressure increase rate is greater than the target pressure increase rate, then reduce the power of the motor.

[0004] By monitoring the real-time pressure increase rate of the air storage tank in real time, the actual air collection effect of the air compressor is monitored, so as to timely adjust the working state of the motor, realize the closed-loop control of the air compressor, and can effectively protect the motor and improve the service life of the air compressor.

[0005] Specifically, the target pressure increase rate is obtained through the following steps: S211: Preset multiple pressure recording points, where the pressure recording points are the pressure values of the gas storage tank; S212: Select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S213: Adjust the pressure of the gas storage tank to the designed minimum pressure value, start the motor, and whenever the pressure of the gas storage tank reaches one of the pressure recording points, record the corresponding test time point until the pressure of the gas storage tank reaches the designed maximum pressure value; S214: Calculate the second absolute difference between two adjacent pressure recording points one by one, as well as the test interval duration of the corresponding test time points; S215: Divide the second absolute difference by the test interval duration to obtain the test pressure increase rate, and mark the test pressure increase rate as the larger one of the two adjacent pressure recording points; S216: Repeat steps S212 to S215 so that each pressure recording point obtains multiple corresponding test pressure increase rates; S217: Calculate the average value of the test pressure increase rates corresponding to each pressure recording point, that is, obtain the target pressure increase rate corresponding to each pressure recording point. During the actual operation of the air compressor, due to different usage conditions, the actual gas collection efficiency of each air compressor is different. By conducting experiments on multiple air compressors of the same model, multiple test pressure increase rates are measured, and the target pressure increase rate is calculated based on the multiple test pressure increase rates. By introducing the first threshold in the actual fault judgment process and filtering out reasonable fluctuations in the pressure increase rate, misjudgment of faults can be effectively avoided.

[0006] Specifically, the first threshold is obtained through the following steps: For each pressure recording point, calculate the range of the multiple test pressure increase rates corresponding to this pressure recording point obtained through step S216, which is the first threshold. The range can effectively cover the fluctuations in the pressure increase rate of the air compressor during normal operation and reduce the probability of misjudging faults.

[0007] Specifically, the real-time pressure increase rate is obtained through the following steps: S221: When the pressure of the gas storage tank reaches the pressure recording point, record the corresponding actual time point; S222: Calculate the actual interval duration between two adjacent pressure recording points based on the actual time points; S223: Divide the second absolute difference by the actual interval duration to obtain the real-time pressure increase rate, and mark this real-time pressure increase rate as the larger one of the two adjacent pressure recording points. By recording the real-time pressure increase rate through the pressure recording points, the real-time pressure increase rate can be accurately compared with the target pressure increase rate at the same pressure level to accurately judge the actual working state of the air compressor.

[0008] Further, the steps of sending out the fault prompt include: S401: Obtain the real-time intake air flow rate at the piston intake port and the real-time gas collection flow rate at the piston outlet port; S402: Calculate the third absolute difference between the real-time intake air flow rate and the target intake air flow rate, and compare the third absolute difference with a second threshold, calculate the fourth absolute difference between the real-time gas collection flow rate and the target gas collection flow rate, and compare the fourth absolute difference with a third threshold; S403: If the third absolute difference is greater than the second threshold and the fourth absolute difference is greater than the third threshold, send out a piston seal ring fault alarm. If only the third absolute difference is greater than the second threshold, send out an intake valve plate fault alarm. If only the fourth absolute difference is greater than the third threshold, send out a gas collection valve plate fault alarm. Faults in the intake valve plate, gas collection valve plate, and seal ring in the piston will cause different phenomena. By collecting different data and analyzing them, the faulty component can be accurately judged.

[0009] Specifically, the target intake air flow rate and the target gas collection flow rate are obtained through the following steps: S501: Preset a plurality of pressure recording points, where the pressure recording points are the pressure values of the air storage tank; S502: Select an air compressor that has not participated in the test from a plurality of air compressors of the same model as the test object; S503: Adjust the pressure of the air storage tank to the designed minimum pressure value, start the motor, and whenever the pressure of the air storage tank reaches one of the pressure recording points, record the corresponding test intake air flow rate and test gas collection flow rate until the pressure of the air storage tank reaches the designed maximum pressure value; S504: Repeat steps S502 to S503 so that each pressure recording point obtains a plurality of corresponding test intake air flow rates and a plurality of corresponding test gas collection flow rates; S505: Calculate the average value of the plurality of test intake air flow rates corresponding to each pressure recording point, that is, obtain the target intake air flow rate corresponding to each pressure recording point, and calculate the average value of the plurality of test gas collection flow rates corresponding to each pressure recording point, that is, obtain the target gas collection flow rate corresponding to each pressure recording point.

[0010] Specifically, the second threshold and the third threshold are obtained through the following steps: S601: Calculate the range of the plurality of test intake air flow rates corresponding to each pressure recording point obtained in step S504, that is, obtain the second threshold; S602: Calculate the range of the plurality of test gas collection flow rates corresponding to each pressure recording point obtained in step S504, that is, obtain the third threshold.

[0011] Further, in step S403, if the third absolute difference is not greater than the second threshold and the fourth absolute difference is not greater than the third threshold, then gas storage system fault diagnosis is performed, including the following steps: S701: After the motor stops, the pressure value of the gas storage tank and the corresponding real-time pressure drop rate are periodically recorded; S702: Calculate the fifth absolute difference between the real-time pressure drop rate and the target pressure drop rate, and compare the fifth absolute difference with the fourth threshold; S703: If the fifth absolute difference is greater than the fourth threshold, a gas storage system fault prompt is issued. When the piston does not malfunction but the air compressor still cannot collect gas normally, it is necessary to determine whether the gas storage system malfunctions. By comparing the rate of air pressure drop in the gas storage system when the motor is not working with the normal rate, it is determined whether there is a fault in the gas storage system.

[0012] The present application also provides an air compressor automatic control system, which includes a data collection module, a data processing module, and a control module. The data collection module is used to periodically obtain the real-time pressure value of the gas storage tank and the corresponding real-time pressure increase rate. The data processing module is used to calculate the first absolute difference between the real-time pressure increase rate and the target pressure increase rate corresponding to the same pressure value, and compare the first absolute difference with the first threshold. If the first absolute difference is greater than the first threshold, then compare the magnitudes of the real-time pressure increase rate and the target pressure increase rate. The control module is used to control the power of the motor according to the result output by the data processing module, or issue a fault prompt.

[0013] The present application also provides an air compressor, including the above control system.

[0014] The technical effects and advantages of the present invention:

[0015] 1. By real-time monitoring the real-time pressure increase rate of the gas storage tank, the actual gas collection effect of the air compressor is monitored, so as to timely adjust the working state of the motor, realize the closed-loop control of the air compressor, and can effectively protect the motor and improve the service life of the air compressor;

[0016] 2. By comparing the absolute difference between the real-time pressure increase rate and the target pressure increase rate with the first threshold, the reasonable fluctuations of the real-time pressure increase rate of the gas storage tank are filtered out, and misjudgment of faults can be effectively avoided.

[0017] 3. By real-time monitoring the real-time pressure increase rate of the gas storage tank and the operating state of the motor, it is determined whether the air compressor malfunctions, and then the cause of the fault is analyzed according to specific data, and an accurate fault prompt is given. Description of the Drawings

[0018] Figure 1 Flow chart of the automatic control method provided by the first embodiment of the present invention;

[0019] Figure 2 Flow chart of the method for obtaining the target pressure increase rate in the first embodiment of the present invention;

[0020] Figure 3 Flow chart of the method for obtaining the real-time pressure increase rate in the first embodiment of the present invention;

[0021] Figure 4 Flow chart of the fault diagnosis in the second embodiment of the present invention;

[0022] Figure 5 Schematic diagram of the control system provided by the third embodiment of the present invention;

[0023] Figure 6 Schematic diagram of the connection relationship of each component of the air compressor provided by the fourth embodiment of the present invention. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] Embodiment 1

[0026] Refer to Figures 1 - 3 , the first embodiment of the present invention provides an automatic control method for an air compressor, including the following steps: S1: After the motor is started, periodically obtain the real-time pressure value of the air storage tank and the corresponding real-time pressure increase rate; S2: Calculate the first absolute difference between the real-time pressure increase rate and the corresponding target pressure increase rate at the same pressure value; S3: Compare the first absolute difference with a first threshold. If the first absolute difference is greater than the first threshold, then compare the magnitudes of the real-time pressure increase rate and the target pressure increase rate; S4: If the real-time pressure increase rate is less than the target pressure increase rate, then at least based on the motor temperature, room temperature, and the motor temperature rise curve, determine whether the power of the motor can be increased. If the power of the motor cannot be increased, then issue a fault prompt; S5: If the real-time pressure increase rate is greater than the target pressure increase rate, then reduce the power of the motor.

[0027] Due to certain differences in the production, installation, and commissioning processes, and also due to certain differences in the degree of newness of each air compressor, when the air compressor is actually operating, there may still be room for improvement in the actual pressure increase rate of its air storage tank. Or perhaps the actual pressure increase rate of the air storage tank does not reach the design index, so the air collection speed can be increased by increasing the power of the motor.

[0028] Specifically, the method for obtaining the target pressure increase rate is mainly obtained through experiments on multiple air compressors of the same model. During the experiment, the pressure value of the air storage tank can be recorded at fixed time intervals, and then the pressure increase rate between two adjacent pressure values can be calculated. It is also possible to record the time point when the pressure of the air storage tank reaches a fixed pressure value point, and then calculate the time interval between two adjacent pressure values, and then calculate the pressure increase rate. The advantage of the former is that regardless of whether the pressure of the air storage tank rises, it can trigger the pressure value recording step and calculate the pressure increase rate. The disadvantage is that the real-time pressure increase rate cannot be accurately corresponded to the target pressure increase rate at the same pressure level, and it is necessary to find the target pressure increase rate closest to the pressure level where the real-time pressure increase rate is located, which will inevitably lead to a certain error, and the size of the error depends on the detailed degree of the target pressure increase rate record. The advantage of the latter is that the pressure increase rate can be accurately compared with the target pressure increase rate at the same pressure level. The disadvantage is that when a failure occurs in the piston and the pressure of the air storage tank cannot be increased, the pressure value of the air storage tank cannot reach the recording point, and the comparison step cannot be triggered. An additional fault judgment method needs to be added. For example, when the next pressure value recording point is not reached after exceeding a predetermined time interval, a fault prompt is issued.

[0029] In the first embodiment of the present application, as Figure 2As shown, the target pressure increase rate is obtained by recording the time point when the pressure of the gas storage tank reaches a fixed pressure value point, and specifically includes the following steps: S211: Preset multiple pressure recording points, where the pressure recording points are the pressure values of the gas storage tank; S212: Select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S213: Adjust the pressure of the gas storage tank to the designed minimum pressure value, start the motor, and record the corresponding test time point whenever the pressure of the gas storage tank reaches one of the pressure recording points until the pressure of the gas storage tank reaches the designed maximum pressure value; S214: Calculate the second absolute difference between two adjacent pressure recording points one by one, and the test interval duration of the corresponding test time points; S215: Divide the second absolute difference by the test interval duration to obtain the test pressure increase rate, and mark the test pressure increase rate as the larger one of the two adjacent pressure recording points; S216: Repeat steps S212 to S215 so that each pressure recording point obtains multiple corresponding test pressure increase rates; S217: Calculate the average value of the test pressure increase rates corresponding to each pressure recording point, that is, obtain the target pressure increase rate corresponding to each pressure recording point.

[0030] Specifically, in the first embodiment of the present application, the first threshold is obtained through the following steps: For each of the pressure recording points, calculate the range of the multiple test pressure increase rates corresponding to this pressure recording point obtained through step S216, which is the first threshold. The range can effectively cover the fluctuations in the pressure increase rate of the air compressor during normal operation and reduce the probability of misjudging faults.

[0031] The first threshold can also be represented by other statistical data of the multiple test pressure increase rates, such as the absolute deviation. The value range of the first threshold determines the accuracy of fault judgment. When the value range of the first threshold is small, it is easier to have a fault prompt. For some air compressors with a longer service life, during the actual working process, the pressure rise rate of the gas storage tank should have a larger difference from the target pressure increase rate. Increasing the value range of the first threshold can effectively avoid false alarms of faults.

[0032] Specifically, in the first embodiment, as Figure 3As shown, the real-time pressure increase rate is obtained through the following steps: S221: When the pressure of the gas storage tank reaches the pressure recording point, record the corresponding actual time point; S222: Calculate the actual interval duration between two adjacent pressure recording points according to the actual time point; S223: Divide the second absolute difference by the actual interval duration to obtain the real-time pressure increase rate, and mark this real-time pressure increase rate as the larger one of two adjacent pressure recording points. The acquisition method of the real-time pressure increase rate is the same as that of the target pressure increase rate. Both are to record the corresponding time points at the preset pressure recording points and calculate the pressure increase rate according to the time interval, so that the real-time pressure increase rate can be accurately compared with the target pressure increase rate at the same pressure level, improving the accuracy of fault diagnosis.

[0033] In the first embodiment, the temperature rise curve of the motor is measured through experiments, or can also be measured by establishing a thermodynamic model of the motor and simulating and analyzing. When conducting the temperature rise curve of the motor, it should be tested under different room temperature environments to obtain the temperature rise curves of the motor under different room temperature environments. The temperature rise curve data can be stored in the control system in the form of electronic data to facilitate the judgment of whether the motor can increase power in step S4.

[0034] Embodiment Two

[0035] In the first embodiment of the present application, when there is a certain gap between the real-time pressure increase rate and the target pressure increase rate and it cannot be improved by increasing the motor power, a fault prompt will be issued. The fault prompt can either simply prompt that the air compressor cannot work properly, or determine the specific fault cause through specific fault diagnosis methods.

[0036] The second embodiment of the present application is an improvement based on the first embodiment. Specifically, as Figure 4 shown, the steps of issuing the fault prompt include: S401: Obtain the real-time intake air flow rate at the piston intake port and the real-time gas collection flow rate at the piston outlet; S402: Calculate the third absolute difference between the real-time intake air flow rate and the target intake air flow rate, and compare the third absolute difference with the second threshold, calculate the fourth absolute difference between the real-time gas collection flow rate and the target gas collection flow rate, and compare the fourth absolute difference with the third threshold; S403: If the third absolute difference is greater than the second threshold and the fourth absolute difference is greater than the third threshold, issue a piston seal ring fault alarm. If only the third absolute difference is greater than the second threshold, issue an intake valve plate fault alarm. If only the fourth absolute difference is greater than the third threshold, issue a gas collection valve plate fault alarm.

[0037] The basic principle of the above steps is that when the intake valve disc, the gas collecting valve disc and the sealing ring in the piston fail, different phenomena will occur. By collecting different data and analyzing them, the faulty components can be accurately judged.

[0038] Specifically, in step 403, if the third absolute difference is not greater than the second threshold, and the fourth absolute difference is not greater than the third threshold, but the real-time pressure increase rate of the gas storage tank is still abnormal, it may be due to a failure in the gas storage system, such as air leakage in the gas storage tank itself, or air leakage at the joint between the gas storage tank and other equipment. Therefore, it is necessary to diagnose the gas storage system failure, including the following steps: S701: After the motor stops, periodically record the pressure value of the gas storage tank and the corresponding real-time pressure decrease rate; S702: Calculate the fifth absolute difference between the real-time pressure decrease rate and the target pressure decrease rate, and compare the fifth absolute difference with the fourth threshold; S703: If the fifth absolute difference is greater than the fourth threshold, issue a gas storage system failure prompt.

[0039] In the above steps, the target intake air flow rate and the target gas collecting air flow rate are obtained in a similar way to the target pressure increase rate, that is, when the pressure of the gas storage tank reaches a preset pressure recording point, the corresponding intake air flow rate and gas collecting air flow rate are recorded.

[0040] Specifically, it includes the following steps: S501: Preset multiple pressure recording points, where the pressure recording points are the pressure values of the gas storage tank; S502: Select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S503: Adjust the pressure of the gas storage tank to the designed minimum pressure value, start the motor, and whenever the pressure of the gas storage tank reaches one of the pressure recording points, record the corresponding test intake air flow rate and test gas collecting air flow rate until the pressure of the gas storage tank reaches the designed maximum pressure value; S504: Repeat steps S502 to S503 so that each pressure recording point obtains multiple corresponding test intake air flow rates and multiple corresponding test gas collecting air flow rates; S505: Calculate the average value of the multiple test intake air flow rates corresponding to each pressure recording point, that is, obtain the target intake air flow rate corresponding to each pressure recording point, and calculate the average value of the multiple test gas collecting air flow rates corresponding to each pressure recording point, that is, obtain the target gas collecting air flow rate corresponding to each pressure recording point.

[0041] Further, the second threshold is obtained through step S601: calculate the range of multiple test inhalation flows corresponding to each pressure recording point obtained in step S504, that is, obtain the second threshold; the third threshold is obtained through step S602: calculate the range of multiple test gas collection flows corresponding to each pressure recording point obtained in step S504, that is, obtain the third threshold.

[0042] Embodiment III

[0043] The present application also provides an automatic control system for an air compressor, as Figure 5 shown. The control system includes a data collection module, a data processing module, and a control module. The data collection module is used to periodically obtain the real-time pressure value of the air storage tank. The data processing module is used to calculate the real-time pressure increase rate corresponding to the real-time pressure value, and the first absolute difference between the real-time pressure increase rate and the target pressure increase rate corresponding to the same pressure value, and compare the first absolute difference with the first threshold. If the first absolute difference is greater than the first threshold, then compare the magnitudes of the real-time pressure increase rate and the target pressure increase rate. The control module is used to control the power of the motor or issue a fault prompt according to the result output by the data processing module.

[0044] Embodiment IV

[0045] The present application also provides an air compressor including the above control system.

[0046] Specifically, referring to Figure 6 , the air compressor further includes: a motor, an air storage tank, a piston, a pressure sensor, a first flow sensor, a second flow sensor, and a control component. The piston is used to supply gas to the air storage tank. The motor is used to drive the piston to deliver gas into the air storage tank. The motor has a temperature sensor for measuring the temperature of the motor winding. The pressure sensor is used to measure the pressure of the gas in the air storage tank. The first flow sensor is used to measure the gas flow at the intake port of the piston. The second flow sensor is used to measure the gas flow at the outlet port of the piston. The motor, the pressure sensor, the first flow sensor, and the second flow sensor are all electrically connected to the control component.

[0047] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatic control method for an air compressor, characterized in that, It includes the following steps: S1: After the motor starts, periodically obtain the real-time pressure value of the air storage tank and the corresponding real-time pressure increase rate; S2: Calculate the first absolute difference between the real-time pressure increase rate and the target pressure increase rate corresponding to the same pressure value; S3: Compare the first absolute difference with a first threshold. If the first absolute difference is greater than the first threshold, then compare the magnitudes of the real-time pressure increase rate and the target pressure increase rate; S4: If the real-time pressure increase rate is less than the target pressure increase rate, then at least based on the motor temperature, room temperature, and the motor temperature rise curve, determine whether the power of the motor can be increased. If the power of the motor cannot be increased, then issue a fault prompt; S5: If the real-time pressure increase rate is greater than the target pressure increase rate, then reduce the power of the motor; The target pressure increase rate is obtained through the following steps: S211: Preset multiple pressure recording points, and the pressure recording points are the pressure values of the air storage tank; S212: Select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S213: Adjust the pressure of the air storage tank to the designed minimum pressure value, start the motor, and whenever the pressure of the air storage tank reaches one of the pressure recording points, record the corresponding test time point until the pressure of the air storage tank reaches the designed maximum pressure value; S214: Calculate the second absolute difference between two adjacent pressure recording points and the test interval duration of the corresponding test time points one by one; S215: Divide the second absolute difference by the test interval duration to obtain the test pressure increase rate, and mark the test pressure increase rate as the larger one of the two adjacent pressure recording points; S216: Repeat steps S212 to S215 so that each pressure recording point obtains multiple corresponding test pressure increase rates; S217: Calculate the average value of the test pressure increase rates corresponding to each pressure recording point, that is, obtain the target pressure increase rate corresponding to each pressure recording point.

2. The automatic control method of an air compressor according to claim 1, wherein The first threshold is obtained through the following steps: For each pressure recording point, calculate the range of the multiple test pressure increase rates corresponding to this pressure recording point obtained through step S216, which is the first threshold corresponding to this pressure recording point.

3. The automatic control method of an air compressor according to claim 1, wherein The real-time pressure increase rate is obtained through the following steps: S221: When the pressure of the air storage tank reaches the pressure recording point, record the corresponding actual time point; S222: Calculate the actual interval duration between two adjacent pressure recording points according to the actual time point; S223: Divide the second absolute difference by the actual interval duration to obtain the real-time pressure increase rate, and mark this real-time pressure increase rate as the larger one of the two adjacent pressure recording points.

4. The automatic control method of an air compressor according to claim 1, characterized in that, The steps for issuing the fault prompt include: S401: Obtain the real-time intake air flow rate at the piston intake port and the real-time gas collection flow rate at the piston outlet port; S402: Calculate the third absolute difference between the real-time intake air flow and the target intake air flow, compare the third absolute difference with the second threshold, calculate the fourth absolute difference between the real-time gas collection flow and the target gas collection flow, and compare the fourth absolute difference with the third threshold; S403: If the third absolute difference is greater than the second threshold and the fourth absolute difference is greater than the third threshold, issue a piston seal ring fault alarm. If only the third absolute difference is greater than the second threshold, issue an intake valve plate fault alarm. If only the fourth absolute difference is greater than the third threshold, issue a gas collection valve plate fault alarm.

5. The automatic control method of an air compressor according to claim 4, wherein, The target intake air flow and the target gas collection flow are obtained through the following steps: S501: Preset multiple pressure recording points, where the pressure recording points are the pressure values of the gas storage tank; S502: Select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S503: Adjust the pressure of the gas storage tank to the designed minimum pressure value, start the motor, and record the corresponding test intake air flow and test gas collection flow whenever the pressure of the gas storage tank reaches one of the pressure recording points until the pressure of the gas storage tank reaches the designed maximum pressure value; S504: Repeat steps S502 to S503 so that each pressure recording point obtains multiple corresponding test intake air flows and multiple corresponding test gas collection flows; S505: Calculate the average value of the multiple test intake air flows corresponding to each pressure recording point, that is, obtain the target intake air flow corresponding to each pressure recording point, calculate the average value of the multiple test gas collection flows corresponding to each pressure recording point, that is, obtain the target gas collection flow corresponding to each pressure recording point.

6. The automatic control method of an air compressor according to claim 5, characterized in that, The second threshold and the third threshold are obtained through the following steps: S601: Calculate the range of the multiple test intake air flows corresponding to each pressure recording point obtained in step S504, that is, obtain the second threshold; S602: Calculate the range of the multiple test gas collection flows corresponding to each pressure recording point obtained in step S504, that is, obtain the third threshold.

7. The automatic control method of an air compressor according to claim 4, wherein In step S403, if the third absolute difference is not greater than the second threshold and the fourth absolute difference is not greater than the third threshold, the gas storage system fault diagnosis is performed through the following steps: S701: After the motor stops, periodically record the pressure value of the gas storage tank and the corresponding real-time pressure drop rate; S702: Calculate the fifth absolute difference between the real-time pressure drop rate and the target pressure drop rate, and compare the fifth absolute difference with the fourth threshold; S703: If the fifth absolute difference is greater than the fourth threshold, issue a gas storage system fault prompt.

8. An automatic control system for an air compressor, characterized in that, For implementing the control method according to any one of claims 1-7, the control system includes: A data collection module for periodically obtaining the real-time pressure value of the gas storage tank and the corresponding real-time pressure increase rate; A data processing module, configured to calculate a first absolute difference between the real-time pressure increase rate and the corresponding target pressure increase rate at the same pressure value, and compare the first absolute difference with a first threshold. If the first absolute difference is greater than the first threshold, then compare the magnitudes of the real-time pressure increase rate and the target pressure increase rate; A control module, configured to control the power of the motor or issue a fault prompt according to the result output by the data processing module.

9. An air compressor, characterized in that, It includes the control system according to claim 8.

Images