Energy-saving control method of alternating current motor, computer equipment and storage medium
By obtaining the initial signal of the AC motor, and adjusting the motor running signal using equivalent circuit model and optimization algorithm, the ineffective energy consumption problem of the AC motor is solved, and the energy utilization rate and dynamic response speed are improved.
Patent Information
- Application Number
- CN202510452469.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-07-15
AI Technical Summary
Existing AC motors have a large amount of ineffective energy consumption during use, resulting in poor energy utilization, especially in the fixed frequency adjustment mode that cannot adapt to dynamic load changes and low power factor during light loads.
By obtaining the initial signals such as voltage, current and speed of the AC motor, using an equivalent circuit model for parameter identification, combining gradient descent algorithm and model prediction control, optimizing the target operation data, adjusting the motor operation signal to reduce energy consumption, and implementing feedforward compensation control and active filtering device for real-time compensation when the load suddenly changes.
It has achieved the reduction of energy consumption and improvement of energy utilization of AC motors, improved dynamic response speed, and improved light load energy efficiency, solving the problem that the fixed frequency adjustment mode cannot adapt to dynamic load changes.
Smart Images
Figure CN120320656A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of computer technology, and particularly relates to an energy-saving control method for an AC motor, a computer device, and a storage medium. Background Art
[0002] An AC motor is a motor that converts electrical energy into mechanical energy through the principle of electromagnetic induction. Its main components include a stator, a rotor, a power supply, and a control system. Among them, the stator and the rotor are the core components of the motor, and they interact with each other through the principle of electromagnetic induction to achieve the conversion of mechanical energy.
[0003] However, existing AC motors generate a large amount of ineffective energy consumption during use, resulting in poor energy utilization efficiency of the AC motor. Summary of the Invention
[0004] The technical problem to be solved by this application is how to provide an energy-saving control strategy for an AC motor to reduce the ineffective energy consumption of the AC motor, thereby improving the energy utilization efficiency of the AC motor.
[0005] To solve the above problems, in a first aspect, this application provides an energy-saving control method for an AC motor. The method includes: obtaining a plurality of initial signals of the AC motor, where the initial signals include at least one of the voltage, current, and speed when the AC motor is running; inputting the initial signals into an equivalent circuit model, and performing parameter identification based on the equivalent circuit model to obtain the first parameters of the AC motor; inputting the first parameters into an objective function with the minimum energy loss, and obtaining target operating data based on the objective function; adjusting the operating signals of the AC motor based on the target operating data.
[0006] In an optional embodiment, the gradient descent algorithm is used to solve the objective function to obtain the target operating data; where the target operating data includes at least a target voltage and a target frequency.
[0007] In an optional embodiment, the objective function can be expressed by the following formula:
[0008] J(V,f) = 3×I1 2 ×R1 + I2 2 ×(R2 / s) + (V / f) 2 / Rm×(K1×f + K2×f 2 ) + K v ×ω r 2 ;
[0009] Among them, J(V, f) is a loss function that varies based on voltage V and frequency f; R1, R2 / s, and Rm are equivalent resistances obtained based on the above equivalent circuit model; I1 is the stator terminal current; I2 is the rotor terminal current; K1 and K2 are iron loss coefficients, which can be obtained based on the factory calibration value of the AC motor and the temperature compensation factor; Kv×ωr2 is mechanical loss.
[0010] In an alternative embodiment, the recursive least squares method with a forgetting factor is used for parameter identification, where the value range of the forgetting factor λ is 0.9 to -0.99.
[0011] In an alternative embodiment, the operating signal includes voltage amplitude and voltage frequency.
[0012] In an alternative embodiment, the method further includes: starting feedforward compensation control when the load of the AC motor suddenly changes, and the gain of the feedforward compensation is calculated according to the following formula: Kf = ΔT / (J×Δω), where Kf is the gain of the feedforward compensation, J is the moment of inertia, ΔT is the change in torque, and Δω is the change in angular velocity.
[0013] In an alternative embodiment, the DC bus side of the AC motor includes an active filtering device, and the method further includes: detecting the load current in real time through the active filtering device and generating a reverse compensation current based on the detection result and injecting it into the power grid.
[0014] In an alternative embodiment, adjusting the operating signal of the AC motor based on the target operating data includes: generating a PWM modulation signal based on model predictive control to achieve coordinated control of the voltage amplitude and the voltage frequency.
[0015] In a second aspect, the present application further provides an energy-saving control device for an AC motor, which may include:
[0016] An initial signal acquisition module, configured to acquire a plurality of initial signals of the AC motor, where the initial signals include at least one of voltage, current, and speed when the AC motor is operating;
[0017] A parameter identification module, configured to input the initial signals into an equivalent circuit model and perform parameter identification based on the equivalent circuit model to obtain the first parameters of the AC motor;
[0018] A target function calculation module, configured to input the first parameters into an objective function with minimum energy loss and obtain target operating data based on the objective function;
[0019] An adjustment module, configured to adjust the operating signal of the AC motor based on the target operating data.
[0020] In a third aspect, the present application further provides a computer device, which includes a memory and a processor. The memory stores a computer program, and when the program is executed by the processor, it can implement the steps of any one of the above methods.
[0021] In a fourth aspect, the present application further provides a storage medium for storing a computer program, and when the program is executed by a computer or a processor, it implements the steps of any one of the above methods.
[0022] Compared with the prior art, the technical solutions of the embodiments of the present application have the following beneficial effects:
[0023] The energy-saving control method of the AC motor in the embodiment of the present application can detect initial signals such as the voltage, current, and speed of the AC motor in real time, perform parameter identification on the equivalent circuit model based on the initial signals, calculate the energy loss of the AC motor based on the parameter identification results, obtain the target operation data of the AC motor when the energy loss is minimized, and control the operation of the AC motor based on the target operation data. Thus, it can accurately adjust the operation signal of the AC motor according to the current operation condition of the AC motor, effectively reduce the energy consumption of the AC motor, and improve the energy utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is a schematic flow chart of an energy-saving control method for an AC motor according to an embodiment of the present application;
[0025] Figure 2 is a schematic diagram of a T-type equivalent circuit of a three-phase asynchronous motor according to an embodiment of the present application;
[0026] Figure 3 is a schematic structural diagram of an energy-saving control device for an AC motor according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] As mentioned in the background art, a large amount of ineffective energy consumption is generated during the use of existing AC motors, resulting in poor energy utilization rate of the AC motors.
[0028] Specifically, the main reasons for the generation of ineffective energy consumption during the use of AC motors at least include the following points: The fixed-frequency adjustment mode of AC motors cannot adapt to dynamic load changes; The power factor is low during light load of AC motors, resulting in an increase in ineffective energy consumption; There is a problem of response lag in using traditional PID control in AC motors, where PID control refers to proportional, integral, and differential control.
[0029] To solve the above problems, the present invention proposes an energy-saving control method for an AC motor, which can be executed by the control end of the AC motor.
[0030] To further elaborate on the technical means and effects adopted by this application to achieve the intended application purpose, the following specifically describes the specific implementation manners and effects of the energy-saving control method for an AC motor proposed according to this application in conjunction with the accompanying drawings and preferred embodiments as follows.
[0031] According to the first aspect of this application, please refer to Figure 1 , Figure 1 which is a schematic flowchart of an energy-saving control method for an AC motor according to an embodiment of this application. The method includes the following steps S101, S102, S103, and S104, and the following specifically describes each step.
[0032] Step S101: Obtain multiple initial signals of the AC motor, where the initial signals include at least one of the voltage, current, and rotational speed when the AC motor is operating.
[0033] Specifically, during the operation of the AC motor, the voltage signal, current signal, rotational speed, etc. of the AC motor can be collected in real time as initial signals.
[0034] Furthermore, the three-phase current and voltage signals of the motor can be collected in real time through a Hall sensor group, and the rotational speed of the rotor can be obtained in combination with a rotational speed sensor.
[0035] It should be noted that the initial signals include but are not limited to the above examples, and other operating signals of the AC motor can also be used as initial signals.
[0036] Step S102: Input the initial signals into an equivalent circuit model, and perform parameter identification based on the equivalent circuit model to obtain the first parameters of the AC motor.
[0037] Among them, the equivalent circuit model is used to represent the circuit of the AC motor. There are various types of AC motors, such as asynchronous motors and servo motors. For different types of AC motors, their corresponding equivalent circuit models are also different.
[0038] In a specific embodiment, please refer to Figure 2 , Figure 2 which is a schematic diagram of the T-type equivalent circuit of a three-phase asynchronous motor. Among them, U1 is the stator terminal voltage; R1 is the stator winding resistance; jX1 is the reactance generated by the stator leakage flux; R2 / s is the rotor equivalent resistance, which changes with the slip s, and s = (n s -n) / n s , where n is the actual rotational speed, and n sis the synchronous speed; jX2 is the leakage reactance of the rotor flux; Rm is the equivalent resistance of the core loss, which may include hysteresis loss and eddy current loss, etc.; jXm is the magnetizing reactance of the main flux. Further, the identified parameters may include R1, R2 / s, and Rm, etc.
[0039] In an alternative embodiment, the parameters of the equivalent circuit can be identified by at least one of the following methods: the least squares method; the extended Kalman filtering method; intelligent optimization algorithms such as genetic algorithms and particle swarm optimization.
[0040] In a preferred embodiment, the recursive least squares method with a forgetting factor is used to identify the parameters of the equivalent circuit model, where the value range of the forgetting factor λ is 0.9 to -0.99. This can balance the weights of new and old data, adapt to the time-varying characteristics of the parameters, and improve the accuracy of parameter identification.
[0041] Step S103, input the first parameter into the objective function with the minimum energy loss, and obtain the target operating data based on the objective function.
[0042] Among them, the target operating data is the data used to adjust the operating conditions of the AC motor, which may include the target voltage and target frequency, etc.
[0043] In an alternative embodiment, the objective function can be expressed by the following formula (1):
[0044] J(V,f) = 3 × I1 2 × R1 + I2 2 × (R2 / s) + (V / f) 2 / Rm × (K1 × f + K2 × f 2 ) + K v × ω r 2 (1)
[0046] Among them, J(V,f) is the loss function that varies based on the voltage V and frequency f; R1, R2 / s, and Rm are the equivalent resistances obtained based on the above equivalent circuit model respectively; I1 is the stator terminal current; I2 is the rotor terminal current; K1 and K2 are the iron loss coefficients respectively, which can be obtained according to the factory calibration values and temperature compensation factors of the AC motor; K v × ω r 2 is the mechanical loss.
[0047] By solving the minimum value of the loss function in formula (1), the combination of voltage and frequency with the minimum loss can be obtained. Controlling the operation of the AC motor through the obtained combination of voltage and frequency can reduce the loss of the AC motor and achieve energy-saving control of the AC motor.
[0048] In an alternative embodiment, when solving for the minimum loss of the objective function (such as the function of Equation (1)), the gradient descent algorithm can be used to quickly and accurately obtain the target operating data corresponding to the minimum loss. Specifically, calculate the gradients of the objective function with respect to voltage V and frequency f, and then adjust the values of voltage V and frequency f in the opposite direction of the gradient until convergence to the minimum value. It should be noted that the operating parameters of the motor are constrained. For example, the voltage and frequency cannot exceed the rated values, otherwise the equipment may be damaged. Therefore, after each update in gradient descent, it is necessary to perform constraint processing on V and f, such as limiting them within a reasonable range.
[0049] Optionally, the gradient descent algorithm can be non-linearly optimized through constraint conditions.
[0050] Furthermore, the constraint conditions can at least include electrical constraints and / or mechanical constraints.
[0051] Among them, the electrical constraints can be expressed as:
[0052] 0.7Vrated ≤ V ≤ 1.1Vrated, where Vrated is a preset voltage value.
[0053] f min ≤ f ≤ f max where f min is the minimum frequency value and f max is the maximum frequency value.
[0054] V / f ≤ Φ sat where Φ sat is the flux saturation limit value.
[0055] In addition, the gradient descent algorithm is sensitive to the initial values. Different initial points may lead to convergence to different local minima. Therefore, the initial values of V and f can be selected through heuristic algorithms or based on motor operating experience, or combined with other optimization methods (such as particle swarm optimization) to find better initial values.
[0056] Moreover, the gradient descent algorithm may get stuck in local minima. If there are multiple local minima, global optimization methods can be used, or random perturbations (such as stochastic gradient descent) can be added during gradient descent to jump out of the local optimum.
[0057] Step S104, adjust the operating signal of the AC motor based on the target operating data.
[0058] Among them, the operating signal can include signals such as the voltage, current, and speed of the AC motor.
[0059] In an alternative embodiment, the operating signal of the AC motor can be directly adjusted to the target operating data.
[0060] In another alternative embodiment, in order to avoid mutations in the operating data, the operating signal of the AC motor can be gradually adjusted according to a certain control logic so that the operating signal gradually approaches the target operating data.
[0061] By Figure 1 The provided energy-saving control method for an AC motor can detect initial signals such as the voltage, current, and speed of the AC motor in real time, identify the parameters of the equivalent circuit model based on the initial signals, calculate the energy loss of the AC motor based on the parameter identification results, obtain the target operating data of the AC motor when the energy loss is minimized, and control the operation of the AC motor based on the target operating data. Thus, the operating signal of the AC motor can be accurately adjusted according to the current operating condition of the AC motor, effectively reducing the energy consumption of the AC motor and improving the energy utilization rate.
[0062] In a specific embodiment, the operating signal includes the voltage amplitude and the voltage frequency. Figure 1 In step S104, adjusting the operating signal of the AC motor based on the target operating data may include: generating a Pulse Width Modulation (PWM) signal based on model predictive control to achieve coordinated control of the voltage amplitude and the voltage frequency.
[0063] Specifically, generating a PWM modulation signal based on model predictive control may include: establishing a mathematical model of the motor, including voltage equations, flux linkage equations, etc.; predicting the system state (such as the amplitude and / or frequency of the voltage) in the next few time steps based on the current state and possible control inputs; defining the objectives to be optimized, such as tracking error (deviation of current and speed), switching loss, harmonic distortion, etc.; considering constraint objectives such as the switching frequency of the inverter, voltage limit, current limit, etc.; solving the optimization problem in each control cycle to obtain the optimal voltage vector; and converting the optimized voltage vector into a specific PWM signal to drive the inverter.
[0064] In this embodiment, directly generating a PWM signal through model predictive control realizes the dynamic coordination of the voltage amplitude and frequency, improving the dynamic response speed and light-load energy efficiency compared with traditional methods.
[0065] In an alternative embodiment, the DC bus side of the AC motor includes an active filtering device, and the method further includes: detecting the load current in real time through the active filtering device and generating a reverse compensation current based on the detection result and injecting it into the power grid.
[0066] Specifically, an Active Power Filter (APF) detects the harmonic and reactive components in the load current in real time, generates a reverse compensation current and injects it into the power grid, thereby suppressing harmonics and compensating for reactive power. When applied on the DC bus side, inverter technology needs to be combined to convert DC electrical energy into a controllable AC compensation current.
[0067] Furthermore, the instantaneous reactive power theory can be adopted to separate the harmonic and reactive components in the load current in real time through a Phase Locked Loop (PLL).
[0068] Furthermore, the algorithm for dynamically compensating reactive power can include: constructing a function and minimizing the weighted sum of harmonic current and reactive current based on the function; using Model Predictive Control (MPC) or Proportion Resonant (PR) controller to generate a Pulse Width Modulation (PWM) modulation signal to dynamically adjust the compensation current output by the inverter. Additionally, the reactive power can be dynamically compensated by adjusting the amplitude and phase of the inverter output voltage while maintaining the stability of the DC bus voltage.
[0069] This can solve the problems that the fixed-frequency regulation mode of AC motors cannot adapt to dynamic load changes and the low power factor during light load of AC motors leads to increased ineffective energy consumption, and improve the energy utilization rate of AC motors.
[0070] In an alternative embodiment, Figure 1 the energy-saving method for the AC motor may further include: starting feedforward compensation control when the load of the AC motor suddenly changes, and the gain of the feedforward compensation is calculated according to the following formula (2):
[0071] Kf = ΔT / (J × Δω) (2)
[0072] where Kf is the gain of the feedforward compensation, J is the moment of inertia, ΔT is the change in torque, and Δω is the change in angular velocity.
[0073] Optionally, the sudden change of the load of the AC motor can be detected by at least one of the following methods:
[0074] Method 1: Calculate the change rate of the torque component of the load current in real time, and when the change rate exceeds the threshold, it is considered that a load mutation has occurred; Method 2: Obtain the rotor acceleration through a speed sensor or an observer, and when the acceleration exceeds the threshold, it is considered that a load mutation has occurred; Method 3: Construct an Extended Kalman Filter (EKF) to estimate the load torque in real time, detect its mutation amplitude, and when the amplitude is too large, it is considered that a load mutation has occurred.
[0075] In a preferred embodiment, the above three methods are used simultaneously to detect load mutations of an AC motor. If two or more methods determine that a load mutation has occurred, compensation is triggered, which can avoid misjudgment.
[0076] In another preferred embodiment, the above three methods are used simultaneously to detect load mutations of an AC motor. When one method determines that a load mutation has occurred, compensation is triggered, which can effectively reduce energy consumption.
[0077] In this embodiment, by reasonably designing the feedforward gain, the dynamic response performance of the system to load mutations can be significantly improved.
[0078] In one embodiment, the present application further provides a schematic structural diagram of an energy-saving control device for an AC motor. The energy-saving control device 30 for the AC motor includes:
[0079] An initial signal acquisition module 301, configured to acquire a plurality of initial signals of the AC motor, where the initial signals include at least one of voltage, current, and speed during the operation of the AC motor;
[0080] A parameter identification module 302, configured to input the initial signals into an equivalent circuit model and perform parameter identification based on the equivalent circuit model to obtain first parameters of the AC motor;
[0081] A target function calculation module 303, configured to input the first parameters into a target function with minimum energy loss and obtain target operation data based on the target function;
[0082] An adjustment module 304, configured to adjust the operation signal of the AC motor based on the target operation data.
[0083] In an optional embodiment, the target function calculation module 303 is further configured to solve the target function by using a gradient descent algorithm to obtain the target operation data; wherein, the target operation data includes at least a target voltage and a target frequency.
[0084] In an optional embodiment, the target function can be expressed by the following formula:
[0085] J(V,f) = 3 × I1 2 × R1 + I2 2 × (R2 / s) + (V / f) 2 / Rm × (K1 × f + K2 × f 2 ) + K v × ω r 2 ;
[0086] Among them, J(V, f) is a loss function that varies based on voltage V and frequency f; R1, R2 / s, and Rm are equivalent resistances obtained based on the above equivalent circuit model; I1 is the stator terminal current; I2 is the rotor terminal current; K1 and K2 are iron loss coefficients, which can be obtained according to the factory calibration value of the AC motor and the temperature compensation factor; Kv×ωr2 is the mechanical loss.
[0087] In an alternative embodiment, the recursive least squares method with a forgetting factor is used for parameter identification, where the value range of the forgetting factor λ is 0.9 to -0.99.
[0088] In an alternative embodiment, the operating signal includes the voltage amplitude and the voltage frequency.
[0089] In an alternative embodiment, the energy-saving control device 30 of the AC motor may further include: a feedforward compensation module for starting feedforward compensation control when the load of the AC motor suddenly changes; the gain of the feedforward compensation is calculated according to the following formula: Kf = ΔT / (J×Δω), where Kf is the gain of the feedforward compensation, J is the moment of inertia, ΔT is the change in torque, and Δω is the change in angular velocity.
[0090] In an alternative embodiment, the DC bus side of the AC motor includes an active filtering device, and the energy-saving control device 30 of the AC motor may further include: a load detection module for detecting the load current in real time through the active filtering device and generating a reverse compensation current based on the detection result to inject into the power grid.
[0091] In an alternative embodiment, the adjustment module 304 may further be configured to: generate a PWM modulation signal based on model predictive control to achieve coordinated control of the voltage amplitude and the voltage frequency.
[0092] For more content about the working principle and working mode of the energy-saving control device 30 of the AC motor, reference may be made to the relevant description of the energy-saving control method of the AC motor, which will not be elaborated here.
[0093] The embodiment of the present application further provides a storage medium, specifically a computer-readable storage medium, for storing a computer program, and the program performs the steps of any one of the above energy-saving control methods of the AC motor by a computer or a processor. The computer-readable storage medium may include a non-volatile memory or a non-transitory memory, and may also include optical discs, mechanical hard disks, solid-state drives, etc.
[0094] An embodiment of the present application further provides a computer device, which may include a computer device, comprising a memory and a processor. The memory stores a computer program, and when the program is executed by the processor, it can implement the steps of any one of the above-mentioned energy-saving control methods for AC motors.
[0095] In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.
[0096] In the embodiments of the present application, the memory may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., or may also be a volatile memory, such as a random-access memory (RAM). The memory is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiments of the present application may also be a circuit or any other device capable of implementing a storage function, for storing computer programs and / or data.
[0097] In the energy-saving control method of the AC motor provided by the embodiments of the present application, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program is loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable devices. The computer program can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or a wireless manner (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a digital video disc (DVD)), or a semiconductor medium (such as an SSD), etc.
[0098] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.
[0099] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.
[0100] In the above embodiments, the descriptions of the respective embodiments have their own emphases, and any plurality of embodiments can be combined for use. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0101] In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in the processor or the instructions in the form of software. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by the hardware processor, or executed and completed by the combination of the hardware and software units in the processor. The software unit can be located in a mature storage medium in the art such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. This storage medium is located in the memory, and the processor executes the instructions in the memory and combines its hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.
[0102] In the embodiments of the present application, the processor of the above device may be a central processing unit (CPU), and this processor may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or this processor may also be any conventional processor, etc.
[0103] The embodiments of the present application also provide a computer program product. The above computer program product includes a non-transitory computer-readable storage medium storing a computer program. The above computer program is operable to cause a computer to execute some or all of the steps of any of the methods described in the above method embodiments. This computer program product may be a software installation package.
[0104] In several embodiments provided in the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the above division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical or other form.
[0105] The units described above as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.
[0106] In addition, in each embodiment of the present application, each functional unit can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.
[0107] If the above-mentioned integrated unit 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 memory. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, a server, or a TRP, etc.) to execute all or part of the steps of the methods in the various embodiments of the present application. The aforementioned memory includes: various media such as USB flash drives, read-only memories (ROMs), random access memories (RAMs), mobile hard disks, magnetic disks, or optical discs that can store program codes.
[0108] It should be understood that the term "and / or" in this article is only a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article indicates that the associated objects before and after are in an "or" relationship.
[0109] The term "a plurality of" appearing in the embodiments of the present application refers to two or more.
[0110] The descriptions such as first and second appearing in the embodiments of the present application are only for schematic and distinguishing description objects, without an order, nor do they represent a special limitation on the number of devices in the embodiments of the present application, and cannot constitute any limitation to the embodiments of the present application.
[0111] The term "connection" appearing in the embodiments of the present application refers to various connection methods such as direct connection or indirect connection to achieve communication between devices, and the embodiments of the present application do not make any limitations on this.
[0112] The above has introduced the embodiments of the present application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. An energy-saving control method for an AC motor, characterized in that, The method includes: Obtaining a plurality of initial signals of the AC motor, where the initial signals include at least one of voltage, current, and rotational speed during the operation of the AC motor; Inputting the initial signals into an equivalent circuit model, and performing parameter identification based on the equivalent circuit model to obtain the first parameters of the AC motor; Inputting the first parameters into an objective function with minimum energy loss, and obtaining target operation data based on the objective function; Adjusting the operation signals of the AC motor based on the target operation data.
2. The method according to claim 1, wherein The obtaining of the target operation data based on the objective function includes: Using the gradient descent algorithm to solve the objective function to obtain the target operation data; Wherein, the target operation data includes at least a target voltage and a target frequency.
3. The method according to claim 2, wherein The objective function can be expressed by the following formula: J(V,f) = 3×I1 2 ×R1 + I2 2 T2×(R2 / s) + (V / f) 2 / RmT2×(K1×f + K2×f 2 ) + Kv×ωr 2 ; Wherein, J(V,f) is a loss function varying based on voltage V and frequency f; R1, R2 / s, and Rm are equivalent resistances obtained based on the above equivalent circuit model respectively; I1 is the stator terminal current; I2 is the rotor terminal current; K1 and K2 are iron loss coefficients respectively, which can be obtained according to the factory calibration value of the AC motor and the temperature compensation factor; Kv×ωr2 is the mechanical loss.
4. The method according to claim 1, characterized in that, Using the recursive least squares method with a forgetting factor for parameter identification, where the value range of the forgetting factor λ is 0.9 to -0.
99.
5. The method according to claim 1, wherein The operation signals include voltage amplitude and voltage frequency.
6. The method according to claim 1, wherein The method further includes: Starting feedforward compensation control when the load of the AC motor suddenly changes, and the gain of the feedforward compensation is calculated according to the following formula: Kf = ΔT / (J×Δω), where Kf is the gain of the feedforward compensation, J is the moment of inertia, ΔT is the change in torque, and Δω is the change in angular velocity.
7. The method according to claim 1, characterized in that The DC bus side of the AC motor includes an active filtering device, and the method further includes: Real-time detecting the load current through the active filtering device, and generating a reverse compensation current based on the detection result and injecting it into the power grid.
8. The method according to any one of claims 1 to 7, characterized in that The adjusting of the operation signals of the AC motor based on the target operation data includes: Generating a PWM modulation signal based on model predictive control to achieve coordinated control of the voltage amplitude and the voltage frequency.
9. A computer device, comprising a processor and a storage device, the storage device being adapted to store a plurality of program codes, characterized in that, The program code is suitable for being loaded and run by the processor to execute the method according to any one of claims 1 to 8.
10. A storage medium in which multiple program codes are stored, characterized in that, The program code is suitable for being loaded and run by the processor to execute the method according to any one of claims 1 to 8.