Method, system, device and medium for suppressing compressor torque pulsation based on genetic factor ILC iterative learning

Abstract

This invention discloses a method, system, device, and medium for suppressing compressor torque pulsation based on genetic factor ILC iterative learning. This method relates to the field of permanent magnet synchronous motor control technology. Based on the load characteristics of the compressor, the load torque is observed and directly controlled via q-axis current. Combined with ILC iterative learning control with genetic factor attenuation, this method suppresses the effects of torque disturbances in single-rotor compressors. This method directly addresses the essence of torque pulsation, compensating for it by directly observing and controlling torque, resulting in simple and effective control. Furthermore, the method exhibits self-learning capabilities, enabling adaptive adaptation to the variable external loads of variable-frequency air conditioners, rather than relying on pre-set, rigid parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motor control, and in particular to a method, system, device and medium for suppressing compressor torque pulsation based on genetic factor ILC iterative learning. Background Art

[0002] Compared with fixed-speed air conditioners, variable-speed air conditioners have occupied a major share of the global air conditioner market. Among them, the largest proportion of household variable-speed air conditioners uses single-rotor compressors because of their high cost-effectiveness. For example, Figure 1 However, the pulsation of the torque of the single-rotor compressor in one mechanical cycle will cause harmful vibration and noise. The load fluctuation curve of the single-rotor compressor in each mechanical cycle is as follows: Figure 2 As shown in the figure, the essence of load fluctuation is that the load torque of a single-rotor compressor fluctuates in a shark-fin-like pattern due to the eccentric rotor of the compressor. The pressure in the suction and discharge chambers fluctuates during each rotor rotation, causing the load torque to fluctuate. Therefore, the controller needs to construct a load torque observer to calculate the difference between the output torque Te and the load torque TL in real time. Iterative learning is performed based on the torque error, continuously correcting the output torque to achieve the goal of adapting the control torque to the load torque.

[0003] It can be seen that under different operating conditions of air-conditioning equipment, the load fluctuation degree of the single-rotor compressor is also different, and it cannot be suppressed by pre-setting some compensation data. It is urgently necessary for the controller to have a set of self-adaptive and self-learning methods to dynamically respond to load changes. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method, system, device and medium for suppressing compressor torque pulsation based on genetic factor ILC iterative learning. According to the load characteristics of the compressor, the q-axis current i q Observe the load torque T L , and directly control the torque T e , combined with ILC iterative learning control with genetic factor attenuation design, so as to suppress the influence of torque disturbance of single rotor compressor.

[0005] To achieve the above object, the technical solution of the present invention is implemented as follows:

[0006] In the first aspect, the present invention provides a method for suppressing torque pulsation of a compressor, which is applied to the speed and current double closed-loop control of a permanent magnet synchronous motor. After the park transformation, the q-axis current i q First, it passes through the torque observer control link, then enters the ILC iterative learning control link, and then generates the desired q-axis current i * q, wherein, in the torque observer control link, the q-axis current i q Converted into electromagnetic torque, in the ILC iterative learning control link, the electromagnetic torque is converted into the desired q-axis current i * q .

[0007] In the second aspect, the present invention provides a system for suppressing compressor torque pulsation, which is applied to the speed and current double closed-loop control of the permanent magnet synchronous motor, and is characterized in that after the park transformation, the q-axis current i q First, it passes through the torque observer control unit, then enters the ILC iterative learning control unit, and then generates the desired q-axis current i * q , wherein, in the torque observer control unit, the q-axis current i q Converted into electromagnetic torque, in the ILC iterative learning control unit, the electromagnetic torque is converted into the desired q-axis current i * q .

[0008] In a third aspect, the present invention provides an electronic device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method for suppressing low-frequency jitter of a single-rotor compressor as described above.

[0009] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by a processor to implement the method for suppressing low-frequency jitter of a single-rotor compressor as described above.

[0010] Compared with the prior art, the present invention has the following advantages: the present invention aims at the load characteristics of the compressor, and uses the q-axis current i q Observe the load torque T L , and directly control the torque T e , combined with ILC iterative learning control with genetic factor attenuation design, so as to suppress the influence of torque disturbance of single rotor compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 Schematic diagram of the suction and exhaust structure of a single-rotor compressor in one cycle;

[0013] Figure 2 Load fluctuation diagram of a single-rotor compressor within one mechanical cycle;

[0014] Figure 3 Schematic diagram of compressor variable frequency control based on ILC iterative learning and torque observer;

[0015] Figure 4 A detailed diagram of the ILC iterative learning control unit;

[0016] Figure 5 Illustrations of embodiments of the present invention;

[0017] Figure 6 Speed fluctuation graph before implementation;

[0018] Figure 7 Speed fluctuation diagram after implementing ILC control (1);

[0019] Figure 8 Speed fluctuation diagram after implementing ILC control (2);

[0020] Figure 9 Comparison of speed errors under three conditions. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] Example:

[0023] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] In the description of the present invention, "plurality" means at least two, such as two or three, unless otherwise specifically defined. Furthermore, unless otherwise specified or defined, the terms "mounted," "connected," and "connected" should be understood broadly, meaning, for example, fixed, removable, or integral; mechanical or electrical; direct or indirect through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention.

[0025] The word “exemplary” is used hereinafter to mean “serving as an example, example, or illustration.” Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0026] In order to better understand the technical solutions provided by the embodiments of the present invention, the following briefly introduces the technical background of the technical solutions provided by the embodiments of the present invention, so as to better understand the technical concept of the present invention.

[0027] The basic principle of ILC iterative learning can be simply described as achieving a certain control target through repeated iterative corrections. ILC adopts a "learning through repetition" strategy and has a memory and correction mechanism. It attempts control through the controlled system to correct the deviation of the output trajectory from the given trajectory to generate a new control signal, so that the controlled object can keep up with the target.

[0028] In actual operation, air conditioning compressors experience load characteristics that are not completely cyclical, especially when experiencing temperature fluctuations, frequency changes, or sudden load changes. Instead, they exhibit characteristics similar to genetic factor decay: not only are the load characteristics correlated with the past, but this correlation decreases. To address this unique load characteristic, we propose an iterative learning control algorithm based on genetic factors, combining the ILC algorithm with optimization and improvements.

[0029] Based on this, the present invention provides a method for suppressing low-frequency vibration of a single-rotor compressor, which is applied to the speed and current double closed-loop control of a permanent magnet synchronous motor. Figure 3 Based on the basic principle diagram of permanent magnet synchronous motor speed and current dual closed loop FOC SVPWM control, the design adds Figure 3 The “torque observer control unit” and the “ILC iterative learning control unit” are shown by the dotted lines.

[0030] Among them, the design basis of the torque observer is the electromagnetic torque formula

[0031]

[0032] Where P is the number of rotor poles of the compressor motor, Ψ m is the permanent magnetic flux of the compressor motor rotor, both of which can be considered constant, so the electromagnetic torque can be obtained by the q-axis current i q Observation.

[0033] After considering the motor's cogging torque and the torque ripple caused by current measurement error (T cog 、T ΔI ), the expression of electromagnetic torque is as shown in Equation 2.

[0034]

[0035] According to the torque balance principle of the motor in steady state operation, formula (2)T m In fact, it corresponds to the load moment T L It also corresponds to the desired output control torque T ref .

[0036] From the above formula, we can know that the torque can be converted into the desired q-axis reference current:

[0037]

[0038] The q-axis current is expressed as:

[0039]

[0040] in, is the DC component, is the remaining unknown component.

[0041] The DC component corresponds to the output of the speed loop PI controller. In physical terms, it is the non-fluctuating component of the load torque that needs to be overcome, that is, the DC component; and the remaining component corresponds to the component of the load torque pulsation.

[0042] The goal of iterative self-learning control is to continuously learn the According to this periodic The torque given current of the motor can be derived It is also a periodic signal.

[0043] The load characteristic of the compressor is related to the rotor position angle θ in one mechanical cycle. Therefore, the reference torque current can be expressed as:

[0044]

[0045] Where η(θ) = T cog +T ΔI ,

[0046]

[0047] In each electrical angle cycle, the compensation torque current is generated through iterative self-learning control Load to The iterative self-learning control is as follows:

[0048]

[0049] Where i is the i-th sampling calculation cycle (a mechanical cycle usually contains hundreds of sampling calculation cycles, which is mainly determined by the computing power of the MCU microcontroller and is usually positively correlated with the PWM carrier frequency, see the embodiment),

[0050] e i+1 (θ e )=T * (θ e )-T m,i+1 (θ e ), represents the error between the observed load torque and the controlled output electromagnetic torque;

[0051] Φ and Γ are constant gains, with initial values e0(θ e ) are all zero, and 1-α is the genetic factor, which is to compromise the speed and robustness of self-learning. Figure 4 This is the design of the ILC iterative learning control unit. The addition of the low-pass filter LPF is to remove measurement noise and has no effect on the overall principle of the solution.

[0052] Therefore, the present invention directly reaches the essence of torque pulsation and compensates for it by directly observing and controlling the torque, thereby making the control simple and effective. In addition, the present invention has a self-learning feature and can self-adapt to the variable external load of the variable frequency air conditioner, rather than presetting rigid parameters. Furthermore, the control and adjustment principles of the present invention are in line with human thinking and are practical, economical and easy to maintain.

[0053] The technical solutions in the embodiments of the present invention are clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention:

[0054] See also Figure 5 In this example, the carrier frequency is set to 10KHz, the speed reference value and the actual value are both calibrated to 3000r / min, the target speed of the compressor is given as f=0.3*3000=900r / min, the starting rise time from 0 speed is designed to be 1s, and the total simulation time length is 10s.

[0055] Before implementing the control method of the present invention, the speed control effect is as follows Figure 6 The speed error is: 0.020*3000=60r / min, and the speed fluctuation is: ±6.67%. It should be noted that: Figure 6 The pink line at the top is the position angle θ, and the black line is the phase current. The black broken line at the bottom of the figure is the given target speed, the red broken line is the actual speed, and the blue line is the difference between the two, that is, the speed fluctuation.

[0056] Implement ILC control, design ILC control parameters as Γ=0.2,Φ=0.05,1-α is designed to converge after 10 iterations. Observe the speed error as: 0.0096*3000=28.8r / min, speed fluctuation as: ±3.2% (as Figure 7 )

[0057] The control parameters of ILC were further optimized to be Γ=0.8,Φ=0.05,1-α was designed to converge after 12 iterations. The speed error was observed to be: 0.0018*3000=5.4r / min, and the speed fluctuation was: ±0.6% (such as Figure 8 )

[0058] The speed error comparison results under three conditions are as follows: Figure 9 shown.

[0059] Based on the same inventive concept, the embodiment of the present invention also provides a system for suppressing compressor torque pulsation, which is applied to the speed and current double closed-loop control of the permanent magnet synchronous motor, and is characterized in that after the park transformation, the q-axis current i q First, it passes through the torque observer control unit, then enters the ILC iterative learning control unit, and then generates the desired q-axis current i * q , wherein, in the torque observer control unit, the q-axis current i q Converted into electromagnetic torque, in the ILC iterative learning control unit, the electromagnetic torque is converted into the desired q-axis current i * q .

[0060] Since this system is a system corresponding to the method for suppressing low-frequency vibration of a single-rotor compressor in an embodiment of the present invention, and the principle of solving the problem by this system is similar to that of the method, the implementation of this system can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0061] Based on the same inventive concept, an embodiment of the present invention also provides an electronic device, which includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method for suppressing low-frequency jitter of a single-rotor compressor as described above.

[0062] It is understood that the memory may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function, instructions for implementing the various method embodiments described above, etc.; the data storage area may store data created based on the use of the server, etc.

[0063] The processor may include one or more processing cores. The processor utilizes various interfaces and circuits to connect the various components within the server. It executes various server functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in memory, as well as accessing data stored in memory. Optionally, the processor may be implemented using at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), or programmable logic array (PLA). The processor may integrate one or a combination of a central processing unit (CPU) and a modem. The CPU primarily processes the operating system and application programs, while the modem handles wireless communications. It is understood that the modem may not be integrated into the processor and may be implemented separately via a single chip.

[0064] Since the electronic device is the electronic device corresponding to the method for suppressing low-frequency jitter of a single-rotor compressor in an embodiment of the present invention, and the principle of solving the problem by the electronic device is similar to that of the method, the implementation of the electronic device can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0065] Based on the same inventive concept, an embodiment of the present invention also provides a computer-readable storage medium, which stores at least one instruction, at least one program, a code set or an instruction set. The at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by a processor to implement the method for suppressing low-frequency jitter of a single-rotor compressor as described above.

[0066] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0067] Since the storage medium is the storage medium corresponding to the method for suppressing low-frequency jitter of a single-rotor compressor in an embodiment of the present invention, and the principle of solving the problem by the storage medium is similar to that of the method, the implementation of the storage medium can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0068] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0069] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A method for suppressing torque pulsation of a compressor, applied to the speed and current double closed-loop control of a permanent magnet synchronous motor, characterized in that: After park transformation, the q-axis current i q First, it passes through the torque observer control link, then enters the ILC iterative learning control link, and then generates the desired q-axis current i * q ,in, In the torque observer control link, the q-axis current i q Converted into electromagnetic torque, in the ILC iterative learning control link, the electromagnetic torque is converted into the desired q-axis current i * q , the q-axis current i q Convert to electromagnetic torque, the specific steps are: The electromagnetic torque of the torque observer is expressed as: Where P is the number of rotor poles of the compressor motor, Ψ m is the permanent magnet flux linkage of the compressor motor rotor; Considering the cogging torque T of the motor cog and torque ripple T caused by current measurement error △I After that, the electromagnetic torque of the torque observer should be expressed as: Formula (2) reflects the load torque T L It also corresponds to the desired output control torque T ref , The electromagnetic torque is converted into the desired q-axis current i * q , the specific steps are: Rearrange equation (2) to the desired q-axis reference current: The desired q-axis current is expressed as a DC component superimposed on an unknown component to be determined: in, is the DC component, is the remaining unknown component; Continuously learn through ILC iteration to obtain periodic Then according to the periodic Then derive the expected current of the motor It is also a periodic signal; Since the load characteristics of the compressor are related to the rotor position angle θ of a mechanical cycle, the reference torque current can be expressed as: Where, η(θ)=T cog +T ΔI , In each electrical angle cycle, the compensation torque current is generated through iterative self-learning control Load to Therefore, the pulsating torque is reduced and the motor load torque is finally tracked to the desired reference torque.

2. The method for suppressing compressor torque pulsation according to claim 1, characterized in that: The control of iterative self-learning is as follows: Where i is the i-th sampling calculation period; e i+1 (θ e )=T * (θ e )-T m,i+1 (θ e ), represents the load torque T of this observation m and the electromagnetic torque T of the control output * Error; Φ and Γ are constant gains, initial values e0(θ e ) are all zero, and 1-α is the genetic factor coefficient.

3. A compressor torque pulsation suppression system, applied to the speed and current dual closed-loop control of a permanent magnet synchronous motor, characterized in that: After park transformation, the q-axis current i q First, it passes through the torque observer control unit, then enters the ILC iterative learning control unit, and then generates the desired q-axis current i * q ,in, In the torque observer control unit, the q-axis current i q Converted into electromagnetic torque, in the ILC iterative learning control unit, the electromagnetic torque is converted into the desired q-axis current i * q ; The q-axis current i q Convert to electromagnetic torque, the specific steps are: The electromagnetic torque of the torque observer is expressed as: Where P is the number of rotor poles of the compressor motor, Ψ m is the permanent magnet flux linkage of the compressor motor rotor; Considering the cogging torque T of the motor cog and torque ripple T caused by current measurement error △I After that, the electromagnetic torque of the torque observer should be expressed as: Formula (2) reflects the load torque T L It also corresponds to the desired output control torque T ref , The electromagnetic torque is converted into the desired q-axis current i * q , the specific steps are: Rearrange equation (2) to the desired q-axis reference current: The desired q-axis current is expressed as a DC component superimposed on an unknown component to be determined: in, is the DC component, is the remaining unknown component; Continuously learn through ILC iteration to obtain periodic Then according to the periodic Then derive the expected current of the motor It is also a periodic signal; Since the load characteristics of the compressor are related to the rotor position angle θ of a mechanical cycle, the reference torque current can be expressed as: Where, η(θ)=T cog +T ΔI , In each electrical angle cycle, the compensation torque current is generated through iterative self-learning control Load to Therefore, the pulsating torque is reduced and the motor load torque is finally tracked to the desired reference torque.

4. The compressor torque pulsation suppression system according to claim 3, characterized in that: The control of iterative self-learning is as follows: Where i is the i-th sampling calculation cycle; e i+1 (θ e )=T * (θ e )-T m,i+1 (θ e ), represents the error between the load torque observed this time and the electromagnetic torque output by the control; Φ and Γ are constant gains, and the initial value is e0(θ e ) are all zero, and 1-α is the genetic factor.

5. An electronic device, characterized in that: The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method for suppressing low-frequency jitter of a single-rotor compressor as described in any one of claims 1 to 2.

6. A computer-readable storage medium, characterized in that The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement the method for suppressing low-frequency jitter of a single-rotor compressor as described in any one of claims 1 to 2.

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