Compressor control method, air conditioner and storage medium

Abstract

The invention provides a compressor control method, an air conditioner and a storage medium, and the method comprises the following steps: obtaining a real-time rotating speed and an ideal rotating speed of a motor, and carrying out PI control calculation according to a rotating speed difference value between the ideal rotating speed and the real-time rotating speed to obtain an ideal current; the real-time current of the motor is obtained, and the current difference value between the ideal current and the real-time current is calculated; calculating the actual slip of the motor according to the current difference value; and adjusting the output frequency of the frequency converter according to the actual slip. By applying the compressor control method, motor rotating speed fluctuation can be reduced, and the working efficiency of the air conditioner compressor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular, to a compressor control method, an air conditioner applying the compressor control method, and a computer-readable storage medium applying the compressor control method. Background Art

[0002] The air conditioning compressor is one of the most important components in the air conditioning system. Its main function is to compress the low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure gas, thereby promoting the entire refrigeration cycle. The compressor is mainly controlled by an inverter. The essence of control is to change the speed of the motor by adjusting the frequency of the AC input to the motor, thereby controlling the power of the compressor.

[0003] In most cases, the motor load is not constant. Changes in the motor load will affect the motor running slip, causing the motor speed to change and thus affecting the compressor's working efficiency. The motor slip is closely related to the motor speed. The actual motor speed is determined by the synchronous speed and the slip. When the slip changes due to load changes, the actual motor speed will also change accordingly. For example, if the synchronous speed remains constant, if the slip increases, it means that the lag of the rotor relative to the rotating magnetic field increases, then the actual motor speed will decrease; on the contrary, if the slip decreases, the actual motor speed will increase. For compressors, their working efficiency is closely related to the speed. The suction volume, exhaust volume, and internal gas compression degree of the compressor will be different at different speeds. Generally speaking, the compressor has a suitable working speed range. When the motor speed deviates from this range due to the slip change caused by the load change, it may cause the compressor's suction, exhaust and other working processes to fail to reach the optimal state, thereby affecting its working efficiency, such as poor cooling or heating effects and increased energy consumption.

[0004] Therefore, a more optimized compressor control method needs to be considered. Summary of the invention

[0005] The first object of the present invention is to provide a compressor control method which can reduce motor speed fluctuation and improve the working efficiency of an air-conditioning compressor.

[0006] A second object of the present invention is to provide an air conditioner which can reduce motor speed fluctuation and improve the working efficiency of the air conditioner compressor.

[0007] A third object of the present invention is to provide a computer-readable storage medium that can reduce motor speed fluctuations and improve the operating efficiency of an air-conditioning compressor.

[0008] In order to achieve the above-mentioned first purpose, the compressor control method provided by the present invention includes: obtaining the real-time speed and ideal speed of the motor, performing PI control calculation according to the speed difference between the ideal speed and the real-time speed, and obtaining the ideal current; obtaining the real-time current of the motor, and calculating the current difference between the ideal current and the real-time current; calculating the actual slip of the motor according to the current difference; and adjusting the output frequency of the inverter according to the actual slip.

[0009] It can be seen from the above scheme that the compressor control method of the present invention obtains the ideal current by performing PI control calculation by obtaining the difference between the real-time speed of the motor and the ideal speed, and calculates the actual slip based on the difference between the ideal current and the real-time current, and then adjusts the output frequency of the inverter according to the actual slip, which can quickly respond to the speed error and adjust the motor speed quickly toward the ideal state; the integral link can eliminate the steady-state error, ensuring that the motor can accurately and stably reach the ideal speed after a long period of operation. Such a control method can effectively deal with the speed deviation caused by various factors, and realize more accurate control of the motor speed. In the face of common working condition changes in actual operation such as dynamic changes in motor load and power supply fluctuations, it can also respond in time, and can quickly adjust the frequency converter frequency to restore the motor speed to stability as soon as possible, ensuring that the compressor is not disturbed by external factors and always maintains a good operating state, ensuring that the compressor operates at an appropriate speed, and improving its working performance and stability.

[0010] In a further embodiment, the step of calculating the actual slip of the motor based on the current difference includes: obtaining a current current setting value, calculating a new current setting value based on the current current setting value and the current difference, and determining the actual slip of the motor based on the new current setting value.

[0011] It can be seen that obtaining the current current setting value and calculating the new current setting value in combination with the current difference, and then determining the actual slip of the motor, takes into account the existing settings of the motor under the current control state, because the current current setting value reflects the previous control system's expectations for the motor operation. On this basis, combined with the current difference, the actual slip can be more accurately calculated.

[0012] In a further embodiment, the new current setting value is obtained by the following formula: I n =I o +K i (I * -I); where, I n is the new current setting, I o is the current setting value, K i is the integral gain, I * is the ideal current and I is the real-time current.

[0013] In a further solution, the step of adjusting the output frequency of the inverter according to the actual slip includes: obtaining the current output frequency of the inverter, and calculating a new output frequency of the inverter according to the current output frequency and the actual slip.

[0014] In a further solution, the new output frequency is obtained by the following formula: n =f o +K p (ss a ), where f n is the new output frequency, f o is the current output frequency, K p is the proportional gain, s is the desired slip, s a It is the actual slip.

[0015] In a further embodiment, the expected slip is obtained by the following formula: Among them, n s is the current synchronous speed of the motor, and n is the real-time speed.

[0016] It can be seen that the motor slip is a key indicator to measure the difference between the actual operating state of the motor and the ideal state. The size and direction of the actual slip reflects whether the motor speed is too high or too low and the degree of deviation. By combining it with the current output frequency of the inverter to calculate the new output frequency, targeted and precise adjustment can be achieved.

[0017] In a further solution, when obtaining the real-time speed of the motor, the real-time speed is filtered.

[0018] In a further solution, when obtaining the real-time current of the motor, the real-time current is filtered.

[0019] It can be seen that in the actual industrial environment, there are many electromagnetic interference, mechanical vibration and other factors around the motor when it is running, which will cause the real-time speed and real-time current signals collected by the sensor to be mixed with noise components. Through filtering processing, these noise interferences can be effectively filtered out, and the speed and current data closer to the true value can be restored, thereby providing accurate and reliable basic data for subsequent control calculations.

[0020] In order to achieve the second objective of the present invention, the present invention provides an air conditioner including a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the above-mentioned compressor control method are implemented.

[0021] In order to achieve the third objective of the present invention, the present invention provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a controller, the steps of the above-mentioned compressor control method are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a system schematic diagram of an air conditioner using the compressor control method of the present invention.

[0023] Figure 2 It is a flow chart of an embodiment of a compressor control method of the present invention.

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0025] The compressor control method of the present invention is a computer program applied to an air conditioner and is used to control the compressor of the air conditioner.

[0026] In this embodiment, Figure 1 As shown, the air conditioner includes a main controller 1, a frequency converter 2 and a motor 3 of a compressor. The main controller 1 is used to control the frequency output by the frequency converter 2 to the motor 3, thereby controlling the speed of the motor 3. The motor 3 is also provided with a motor speed sensor (not shown) and a current sensor (not shown). The motor speed sensor monitors the actual speed of the motor in real time, and the current sensor monitors the input current of the motor in real time. The main controller 1 controls the frequency output by the frequency converter 2 according to the actual speed and the input current.

[0027] Compressor control method embodiment:

[0028] See also Figure 2 In this embodiment, when the compressor control method is working, step S1 is first executed to obtain the real-time speed and the ideal speed of the motor, and a PI control calculation is performed according to the speed difference between the ideal speed and the real-time speed to obtain the ideal current.

[0029] In actual operation, the motor load of the compressor often changes. For example, the load conditions of the compressor are different under different cooling or heating requirements. When the load changes, the motor speed will be affected and fluctuate, which will cause the speed difference to change. Therefore, it is necessary to be able to dynamically adjust the ideal current based on this real-time changing speed difference, so that the motor can adapt to the load fluctuation in time and maintain a relatively stable speed. The real-time speed can be obtained by installing a suitable motor speed sensor on the motor. The ideal speed is a target speed value determined in advance based on factors such as the working requirements of the compressor, process settings, or the expected operating state of the system. It is usually set by the operator of the control system according to the actual application scenario. For example, in an air-conditioning compressor, based on the optimal performance requirements in the cooling or heating mode, combined with the specifications of the compressor, an ideal speed value that can enable the air conditioner to achieve good cooling or heating effects and take into account energy consumption and other aspects is set, and it is stored in the relevant parameter storage area of ​​the controller for subsequent control calculations. The speed difference is obtained by subtracting the ideal speed from the real-time speed, such as Figure 1 As shown, n* is the ideal speed, n is the real speed of the motor, and the speed Δn is obtained by subtracting the two speeds. Δn=n * -n, the speed difference is obtained and input into the PI controller for proportional and integral calculation to obtain the ideal current.

[0030] In this embodiment, when the real-time speed of the motor is obtained, the real-time speed is filtered. By filtering the real-time speed, noise interference can be effectively filtered out, and a speed closer to the real value can be restored, thereby improving the detection accuracy.

[0031] After obtaining the ideal current, execute step S2 to obtain the real-time current of the motor and calculate the current difference between the ideal current and the real-time current. Figure 1 As shown, the ideal current I output by the PI controller is * Subtract the current from the real-time current I to obtain the current difference ΔI, ΔI = I * -I.

[0032] Calculating the current difference between the ideal current and the real-time current can intuitively reflect the degree of deviation between the actual operating current of the motor and the desired ideal current, and is the key basis for further analyzing the motor's operating status and subsequent control operations such as slip calculation. For example, if the calculated current difference is a positive value, it means that the current actual motor current is less than the ideal current, which may imply that the motor's operating status has not met expectations, such as load changes that may cause insufficient motor driving force, and corresponding measures need to be taken to adjust; conversely, if the current difference is a negative value, it means that the actual motor current is greater than the ideal current, and there may be motor overload or other abnormal conditions. It is also necessary to further analyze and make corresponding control adjustments based on this difference to ensure that the motor can operate stably and normally, thereby ensuring that the compressor works efficiently under appropriate working conditions.

[0033] In this embodiment, when the real-time current of the motor is obtained, the real-time current is filtered. By filtering the real-time current, noise interference can be effectively filtered out, current data closer to the real value can be restored, and control accuracy can be improved.

[0034] After obtaining the current difference, step S3 is executed to calculate the actual slip of the motor according to the current difference. Because the current fluctuation is more sensitive than the speed, even slight changes can be identified, so calculating the actual slip of the motor according to the current difference can more accurately control the speed stability.

[0035] In this embodiment, the step of calculating the actual slip of the motor according to the current difference includes: obtaining the current current setting value, calculating a new current setting value according to the current current setting value and the current difference, and determining the actual slip of the motor according to the new current setting value. The new current setting value is obtained by the following formula:n =I o +K i (I * -I); where, I n is the new current setting, I o is the current setting value, K i is the preset integral gain, I * is the ideal current and I is the real-time current.

[0036] The current set value is the current reference value previously set by the control system based on factors such as the motor's operating requirements, load conditions, and the desired working state. It is usually stored in the relevant parameter storage area of ​​the controller. This value represents the current that the control system believes the motor should maintain at a certain stage or under specific working conditions. It is an expected setting for the motor's operating current. For example, in the stable operation stage of the compressor, based on the rated power of the compressor, the set speed, and the corresponding load conditions, through relevant theoretical calculations or empirical judgments, a suitable current value is pre-set as the current current set value to guide the motor to work in the expected state.

[0037] The current difference reflects the deviation between the actual current and the ideal current. Calculating the new current setting value based on the current current setting value and the current difference can guide the motor current to return to a reasonable range, making the motor operating state closer to expectations.

[0038] After obtaining the new current setting value, the actual slip of the corresponding motor can be obtained according to the new current setting value. The corresponding relationship between the actual slip and the current setting value can be preset according to experimental data or according to the current-slip characteristic curve in the motor design manual. The new current setting value is obtained by calculating the current current setting value and the current difference, and then the actual slip of the motor is determined according to the new current setting value. It fully combines the current setting state of the motor and the deviation of the actual operation, and can more accurately calculate the actual slip of the motor, which provides a reliable basis for further analysis of the motor operation state, comparison with the expected slip, and corresponding control operations such as inverter frequency adjustment.

[0039] After obtaining the actual slip of the motor, execute step S4 to adjust the output frequency of the inverter according to the actual slip. By monitoring the slip in real time and adjusting the output frequency of the inverter according to the actual slip, the motor speed can be accurately controlled. Regardless of whether the motor slip changes due to load changes, power supply fluctuations or other factors, the output frequency of the inverter can be adjusted in time to keep the motor speed within the desired range, meet the requirements of compressors and other equipment for motor speed stability and accuracy, and ensure the efficient operation of the equipment.

[0040] In this embodiment, the step of adjusting the output frequency of the inverter according to the actual slip includes: obtaining the current output frequency of the inverter, and calculating the new output frequency of the inverter according to the current output frequency and the actual slip. The new output frequency is obtained by the following formula: n =f o +K p (ss a ), where f n is the new output frequency, f o is the current output frequency, K p is the preset proportional gain, s is the expected slip, s a is the actual slip. In this embodiment, the expected slip is obtained by the following formula: Among them, n s is the current synchronous speed of the motor, f is the set frequency of the inverter, p is the number of pole pairs of the motor, and n is the real-time rotation speed.

[0041] Motor slip is a key indicator to measure the difference between the actual operating state of the motor and the ideal state. The size and direction of the slip reflects whether the motor speed is too high or too low and the degree of deviation. By combining it with the current output frequency of the inverter to calculate the new output frequency, and controlling the output frequency of the inverter according to the new output frequency, the output frequency of the inverter can be accurately adjusted, so that the motor speed can more accurately approach and stabilize at the ideal state.

[0042] From the above, it can be seen that the compressor control method of the present invention obtains the ideal current by performing PI control calculation by obtaining the difference between the real-time speed of the motor and the ideal speed, and calculates the slip based on the difference between the ideal current and the real-time current, and then adjusts the output frequency of the inverter according to the slip, which can quickly respond to the speed error and adjust the motor speed quickly toward the ideal state; the integral link can eliminate the steady-state error, ensuring that the motor can accurately and stably reach the ideal speed after a long period of operation. Such a control method can effectively deal with the speed deviation caused by various factors, and realize more accurate control of the motor speed. In the face of common working condition changes in actual operation such as dynamic changes in motor load and power supply fluctuations, it can also respond in time, and can quickly adjust the frequency converter frequency to restore the motor speed to stability as soon as possible, ensuring that the compressor is not disturbed by external factors and always maintains a good operating state, ensuring that the compressor operates at an appropriate speed, and improving its working performance and stability.

[0043] Air conditioner embodiment:

[0044] The air conditioner of this embodiment includes a controller, and the controller implements the steps in the above compressor control method embodiment when executing a computer program.

[0045] For example, the computer program can be divided into one or more modules, one or more modules are stored in the memory and executed by the controller to complete the present invention. One or more modules can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program in the air conditioner.

[0046] The air conditioner may include, but is not limited to, a controller and a memory. Those skilled in the art will appreciate that the air conditioner may include more or fewer components, or a combination of certain components, or different components, for example, the air conditioner may also include input and output devices, network access devices, buses, etc.

[0047] For example, the controller may be a central processing unit (CPU), other general controllers, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general controller may be a microcontroller or any conventional controller, etc. The controller is the control center of the air conditioner, and uses various interfaces and lines to connect the various parts of the entire air conditioner.

[0048] The memory can be used to store computer programs and / or modules. The controller realizes various functions of the air conditioner by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory. For example, the memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound receiving function, a sound conversion to text function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, text data, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0049] Computer readable storage medium embodiment:

[0050] If the air conditioner integrated module of the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the implementation of all or part of the process in the above compressor control method embodiment can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the controller, the steps of the above compressor control method embodiment can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The storage medium may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electric carrier signal and telecommunication signal.

[0051] It should be noted that the above are only preferred embodiments of the present invention, but the design concept of the invention is not limited thereto, and any non-substantial modifications made to the present invention using this concept also fall within the protection scope of the present invention.

Claims

1. A compressor control method, characterized in that: include: Obtaining the real-time speed and the ideal speed of the motor, performing PI control calculation according to the speed difference between the ideal speed and the real-time speed, and obtaining the ideal current; Acquire the real-time current of the motor, and calculate the current difference between the ideal current and the real-time current; Calculating the actual slip of the motor according to the current difference; The output frequency of the frequency converter is adjusted according to the actual slip.

2. The compressor control method according to claim 1, characterized in that: The step of calculating the actual slip of the motor according to the current difference comprises: A current setting value is obtained, a new current setting value is calculated according to the current setting value and the current difference, and an actual slip of the motor is determined according to the new current setting value.

3. The compressor control method according to claim 2, characterized in that: The new current setting value is obtained by the following formula: I n =I o +K i (I * -I); Among them, I n is the new current setting value, I o is the current setting value, K i is the preset integral gain, I * is the ideal current, and I is the real-time current.

4. The compressor control method according to claim 2, characterized in that: The step of adjusting the output frequency of the frequency converter according to the actual slip comprises: The current output frequency of the inverter is obtained, and a new output frequency of the inverter is calculated according to the current output frequency and the actual slip.

5. The compressor control method according to claim 4, characterized in that: The new output frequency is obtained by the following formula: f n =f o +K p (s-s a ); Among them, f n is the new output frequency, f o is the current output frequency, K p is the preset proportional gain, s is the expected slip, s a is the actual slip.

6. The compressor control method according to any one of claims 1 to 5, characterized in that: The expected slip is obtained by the following formula: Among them, n s is the current synchronous speed of the motor, and n is the real-time speed.

7. The compressor control method according to any one of claims 1 to 5, characterized in that: When the real-time rotation speed of the motor is acquired, filtering is performed on the real-time rotation speed.

8. The compressor control method according to any one of claims 1 to 5, characterized in that: When acquiring the real-time current of the motor, filtering is performed on the real-time current.

9. An air conditioner, comprising a processor and a memory, characterized in that: The memory stores a computer program, and when the computer program is executed by the processor, the steps of the compressor control method according to any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the controller, the steps of the compressor control method according to any one of claims 1 to 8 are implemented.

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