A three-phase grid-connected inverter control method and device

Abstract

This invention relates to the field of inverter technology and discloses a control method and apparatus for a three-phase grid-connected inverter. The method includes: establishing a prediction model for the AC output current of the three-phase grid-connected inverter based on the switching states and voltage and current parameters of the inverter's switching transistors; obtaining a sequence of optimal predicted future output current values ​​that meet the inverter's performance indicators based on the current prediction model; solving for the optimal control quantity of the prediction model at the current moment based on the optimal predicted future output current value sequence and the inverter's performance indicators; and obtaining the current moment modulation signal by performing an inverse dq transform on the current moment optimal control quantity, and generating a control signal for the switching transistors using a preset modulation method. The control method and apparatus of this invention can optimize parameters in real time according to system control deviations, breaking through the limitation of traditional control algorithms that can only control the current state, and effectively improving the adaptability and operational stability of the three-phase grid-connected inverter under different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of inverter technology, specifically to a control method and device for a three-phase grid-connected inverter. Background Technology

[0002] In the field of new energy power generation, the control performance of three-phase grid-connected inverters is crucial to the grid connection quality of the system. Currently, the control algorithms of this equipment mostly adopt traditional PI / PID controllers. Although such algorithms are simple to implement and have a wide range of applications, they have obvious technical shortcomings: parameter adjustment is highly dependent on professional knowledge and engineering experience, lacks adaptive capability, and cannot optimize parameters in real time according to changes in system operating status; at the same time, they can only control the current state of the system and do not have the ability to predict the future output state of the inverter. They are difficult to adapt to the actual operating conditions of photovoltaic output fluctuating due to environmental factors and external disturbances on the grid side, which can easily lead to insufficient inverter control accuracy and decreased operating stability, failing to meet the higher requirements of the development of new energy grid-connected technology. Summary of the Invention

[0003] This invention provides a three-phase grid-connected inverter control method and device to solve the problem of insufficient inverter control accuracy.

[0004] In a first aspect, the present invention provides a control method for a three-phase grid-connected inverter, comprising: establishing a prediction model for the AC output current of the three-phase grid-connected inverter based on the switching states and voltage and current parameters of the inverter's switching transistors; obtaining a sequence of optimal predicted future output current values ​​that satisfy the inverter's performance indicators based on the current prediction model; solving for the optimal control quantity of the prediction model at the current moment based on the optimal predicted future output current value sequence and the inverter's performance indicators; obtaining the current moment modulation signal by performing an inverse dq transformation on the current moment optimal control quantity, and generating a control signal for the switching transistors using a preset modulation method.

[0005] In one optional implementation, the process of establishing a prediction model for the AC side output current of a three-phase grid-connected inverter includes: establishing a linear mathematical model of the output current of the three-phase grid-connected inverter based on a mathematical model of the three-phase grid-connected inverter in a three-phase stationary coordinate system, using Clarke transform, Park transform, and feedforward decoupling; discretizing the linear mathematical model of the inverter output current to obtain a controlled autoregressive integral moving average model of the output current of the three-phase grid-connected inverter; and establishing a prediction model for the AC side output current of the three-phase grid-connected inverter by introducing Diophantine equations based on the controlled autoregressive integral moving average model.

[0006] In one alternative implementation, the process of establishing a prediction model for the AC side output current of a three-phase grid-connected inverter further includes: identifying the polynomial parameters of the controlled autoregressive integral moving average model of the output current of the three-phase grid-connected inverter through the recursive least squares method with diminishing memory.

[0007] In one optional implementation, the process of obtaining the optimal predicted value sequence of future output current that satisfies the inverter performance index includes: calculating the difference between the inverter output current reference trajectory at the current moment and the inverter output current predicted value at the current moment to obtain the current difference; establishing an optimization equation for the performance index of the three-phase grid-connected inverter system based on the current difference and the optimal control increment of the inverter output current at the previous moment; and obtaining the optimal predicted value sequence of future output current of the inverter with the minimum performance index of the three-phase grid-connected inverter system as the optimization objective.

[0008] In one optional implementation, the process of obtaining the inverter output current reference trajectory at the current moment includes: obtaining a current reference value by adjusting the difference between the bus voltage reference value and the actual bus voltage sample value through a PI controller; and obtaining the inverter output current reference trajectory at the current moment based on the current reference value and the inverter output current at the previous moment.

[0009] In one optional implementation, the process of solving the current optimal control quantity of the prediction model includes: obtaining the partial derivative equation of the performance index of the three-phase grid-connected inverter system with respect to the control increment; setting the partial derivative equation to 0 to obtain the current optimal control increment of the prediction model in the control time domain; and taking the sum of the current optimal control increment and the previous optimal control quantity as the current optimal control quantity.

[0010] In an optional implementation, the formula for calculating the optimal control increment at the current moment includes an adaptive step factor. Therefore, the process of solving for the optimal control quantity at the current moment in the prediction model further includes: calculating the adaptive step factor based on the inverter output current deviation value and the initial value of the step factor; the adaptive step factor is used to increase the duty cycle of the inverter switching transistor when the inverter output current deviation is greater than a first preset threshold, and to decrease the duty cycle of the inverter switching transistor when the inverter output current deviation is less than a second preset threshold.

[0011] Secondly, the present invention provides a three-phase grid-connected inverter control device, the device comprising: a prediction model establishment module, used to establish a prediction model of the AC side output current of the three-phase grid-connected inverter based on the switching state and voltage and current parameters of the inverter's switching transistors; a prediction module, used to obtain a sequence of optimal predicted future output current values ​​that satisfy the inverter's performance indicators according to the current prediction model; a solution module, used to solve for the optimal control quantity at the current moment of the prediction model based on the sequence of optimal predicted future output current values ​​and the inverter's performance indicators; and a control module, used to obtain a modulation wave signal at the current moment by performing an inverse dq transformation on the optimal control quantity at the current moment, and to generate a control signal for the switching transistors using a preset modulation method.

[0012] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the three-phase grid-connected inverter control method of the first aspect or any corresponding embodiment described above.

[0013] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the three-phase grid-connected inverter control method of the first aspect or any corresponding embodiment described above.

[0014] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the three-phase grid-connected inverter control method of the first aspect or any corresponding embodiment described above.

[0015] Beneficial effects: This invention can dynamically adjust control parameters based on the real-time deviation of the inverter output current, eliminating the need for manual intervention and debugging. This lowers the technical threshold for equipment operation and maintenance and on-site debugging, ensuring that the control parameters always accurately match the real-time operating status of the inverter. It fundamentally solves the drawback of traditional algorithm parameters that cannot be optimized in real time as the system changes.

[0016] This invention establishes a precise prediction model for the AC output current of a three-phase grid-connected inverter, derives the optimal prediction sequence of future output current by combining system performance indicators, and solves for the optimal control quantity based on this. This allows for early response to changes in system operating conditions, effectively reducing inverter output current deviation and improving the accuracy and sinusoidal nature of current output.

[0017] Whether it is the power fluctuation caused by environmental factors such as sunlight and temperature affecting photovoltaic output, or external disturbances such as voltage fluctuations and harmonic interference on the grid side, the control method of this invention can respond quickly and make adjustments, avoiding problems such as excessive peak output current and unstable operation of the inverter, and ensuring the continuous and reliable operation of the three-phase grid-connected inverter under various operating conditions.

[0018] This invention improves the quality of grid-connected current by enhancing the control performance and operational stability of the inverter, making the output of the photovoltaic power generation system more aligned with the grid connection requirements, strengthening the compatibility between the photovoltaic power generation system and the grid, and facilitating the efficient and safe integration of new energy power generation with the grid, thus meeting the needs of large-scale and engineering-oriented development in the new energy power generation industry. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the first type of three-phase grid-connected inverter control method according to an embodiment of the present invention; Figure 2 This is a control block diagram of a three-phase grid-connected inverter control method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0023] According to an embodiment of the present invention, a three-phase grid-connected inverter control method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0024] This embodiment provides a three-phase grid-connected inverter control method. Figure 1 This is a flowchart of a three-phase grid-connected inverter control method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: Step S1: Based on the switching status of the inverter's switching transistors and voltage and current parameters, establish a prediction model for the AC output current of the three-phase grid-connected inverter.

[0025] Specifically, refer to Figure 2 The system acquires the current switching status of the switching transistors in the three-phase grid-connected inverter, as well as the inverter-side filter inductor current (I0). Labc ), voltage across the filter capacitor (U) Cinv ), common coupling point voltage (e abc Key voltage and current parameters, such as those that reflect the real-time operating status of the inverter, are used as the basis for modeling. A mathematical model of a three-phase grid-connected inverter in a three-phase stationary coordinate system is first established.

[0026] Optionally, the process of establishing a prediction model for the AC side output current of a three-phase grid-connected inverter includes: establishing a linear mathematical model of the output current of the three-phase grid-connected inverter based on a mathematical model of the three-phase grid-connected inverter in a three-phase stationary coordinate system, using Clarke transform, Park transform, and feedforward decoupling; discretizing the linear mathematical model of the inverter output current to obtain a controlled autoregressive integral moving average model of the output current of the three-phase grid-connected inverter; and establishing a prediction model for the AC side output current of the three-phase grid-connected inverter by introducing Diophantine equations based on the controlled autoregressive integral moving average model.

[0027] Specifically, the linear mathematical model of the inverter output current is discretized to obtain the controlled auto-regressive integrated moving average (CARIMA) model of the three-phase grid-connected inverter output current. The CARIMA model is as follows: (1) in, A ( z -1 ), B ( z-1 ), C ( z -1 (Regarding z) -1 Model parameters of the polynomial; y ( k )for k The system output at any given time is the inverter output current, which is also the inverter-side filter inductor current I. Labc ; u ( k )for k The system input at any given time is the switching transistor control signal; z -1 It is a shift operator, representing the corresponding value in the previous sampling period; ξ ( k () represents an uncorrelated random sequence, indicating the effect of a class of random noise; =1- z -1 It is a difference operator.

[0028] Based on the CARIMA model of the three-phase grid-connected inverter output current, the predicted value of the future inverter current output is represented by the Diophantine equation using the known control signal and inverter output current information at the current moment. The Diophantine equation is as follows: (2) in, j For predicted length; E j , F j It is by A ( z -1 ) and j are uniquely determined polynomials.

[0029] Based on the Diophantine equation and the CARIMA model of the output current of the three-phase grid-connected inverter, the following can be obtained: k + j The prediction model for the AC output current of a three-phase grid-connected inverter without random noise at any given time is as follows: (3) in, G j ( z -1 ) is a polynomial.

[0030] Optionally, the polynomial parameters of the controlled autoregressive integral moving average model of the output current of the three-phase grid-connected inverter can be obtained by identifying the recursive least squares method with diminishing memory.

[0031] Specifically, the recursive least squares expression for diminishing memory is: (4) (5) (6) in, μ Forgetting factor; L ( k ) is the weighting factor; P ( k ) is a positive definite covariance matrix.

[0032] Step S2: Based on the current prediction model, obtain the optimal predicted value sequence of future output current that meets the inverter performance index.

[0033] Optionally, the process of obtaining the optimal predicted value sequence of future output current that satisfies the inverter performance index includes: calculating the difference between the inverter output current reference trajectory at the current moment and the inverter output current predicted value at the current moment to obtain the current difference; establishing an optimization equation for the performance index of the three-phase grid-connected inverter system based on the current difference and the optimal control increment of the inverter output current at the previous moment; and obtaining the optimal predicted value sequence of future output current of the inverter with the minimum performance index of the three-phase grid-connected inverter system as the optimization objective.

[0034] The performance index expression for a three-phase grid-connected inverter system is as follows: (7) In the formula, w ( k +1) is a reference trajectory weighted by the inverter output current value and the current reference value; N 1. To optimize the initial values ​​in the time domain, it is usually taken as... N 1 = 1; N 2. To optimize the final value in the time domain, N The value of 2 must be greater than B ( z -1 The order of ) M To control the time domain ( M ≤ N ), that is, in M The control quantity remains unchanged after the step; γ ( k )for k The error weight at time step is generally taken as... γ ( k )= γ ; λ ( k )for k The weighting coefficients for the control effect at specific times are usually assumed to be... λ (k )= λ .

[0035] The system reference trajectory mentioned in the performance indicators of a three-phase grid-connected inverter system is: (8) in, j =1,2,3,…, N ; y r Reference current value ; α The softening factor is 0 < α <1.

[0036] Optionally, the process of obtaining the inverter output current reference trajectory at the current moment includes: obtaining a current reference value by adjusting the difference between the bus voltage reference value and the actual bus voltage sample value through a PI controller; and obtaining the inverter output current reference trajectory at the current moment based on the current reference value and the inverter output current at the previous moment.

[0037] Specifically, as described in the reference trajectory It is the reference voltage value of the maximum power point in the PV boost circuit or based on the voltage of the common coupling point. e abc Calculated reference voltage value u ref Compared with the actual bus voltage sampling value u dc The results are obtained by comparison and then processed through a PI controller.

[0038] Based on the AC side output current prediction model of the three-phase grid-connected inverter, the optimal predicted value sequence of future output current that satisfies the inverter system performance indicators is as follows: (9) (10) (11) Equation (9) includes two parts: the unknown quantity at time k and the known quantity. f Represents a known quantity; G , H , F All are parameter matrices composed of parameter sequences; U To control the incremental sequence.

[0039] Step S3: Based on the optimal predicted value sequence of future output current and the inverter performance index, solve for the optimal control quantity of the prediction model at the current moment.

[0040] Optionally, the process of solving the optimal control quantity of the prediction model at the current moment includes: obtaining the partial derivative equation of the performance index of the three-phase grid-connected inverter system with respect to the control increment; setting the partial derivative equation to 0 to obtain the optimal control increment of the prediction model at the current moment in the control time domain; and taking the sum of the optimal control increment at the current moment and the optimal control quantity at the previous moment as the optimal control quantity at the current moment.

[0041] Specifically, solving To obtain the optimal control increment at the current moment of the prediction model for the AC output current of the three-phase grid-connected inverter in the control time domain: (12) (13) (14) (15) in, W For reference trajectory sequence; β ad An adaptive step factor; This is the new matrix after introducing the step factor.

[0042] Optionally, an adaptive step factor is calculated based on the inverter output current deviation value and the initial value of the step factor. The adaptive step factor is used to increase the duty cycle of the inverter switching transistor when the inverter output current deviation is greater than a first preset threshold, so that the inverter output current approaches the desired reference trajectory more quickly, and to decrease the duty cycle of the inverter switching transistor when the inverter output current deviation is less than a second preset threshold, so as to prevent the generation of large current peaks.

[0043] Specifically, the adaptive step factor is shown in the following equation: (16) (17) In the formula, β 0 is the initial value of the step factor, which can be adjusted according to the actual operating characteristics of the inverter and different... β ad The influence of the value on the inverter output current is adjusted. φ For a constant greater than zero, it can be determined according to β ad Select the range that needs to be adjusted; e It is the natural logarithm; err This represents the inverter output current deviation value.

[0044] The optimal control quantity for the inverter prediction model at the current moment is generated based on the optimal control increment at the current moment and the optimal control quantity at the previous moment in the optimal control quantity sequence of the three-phase grid-connected inverter: (18) Step S4: The optimal control quantity at the current moment is obtained by inverse dq transformation to obtain the modulated wave signal at the current moment, and the control signal of the switching transistor is generated by using a preset modulation method.

[0045] It should be noted that the phases required for steps S1 to S4, such as coordinate transformation, are obtained by a phase-locked loop. The specific phase-locking method will not be described in detail here.

[0046] This embodiment also provides a three-phase grid-connected inverter control device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0047] This embodiment provides a three-phase grid-connected inverter control device, the device comprising: The prediction model building module is used to build a prediction model of the AC side output current of a three-phase grid-connected inverter based on the switching state and voltage and current parameters of the inverter's switching transistors. The prediction module is used to obtain the optimal predicted value sequence of future output current that meets the inverter performance indicators based on the current prediction model. The solution module is used to solve for the optimal control quantity of the prediction model at the current moment based on the optimal prediction value sequence of future output current and the inverter performance index. The control module is used to obtain the modulated wave signal at the current time by inverse dq transformation of the optimal control quantity at the current time, and to generate the control signal of the switching transistor using a preset modulation method.

[0048] The three-phase grid-connected inverter control device provided in this embodiment of the invention can execute the three-phase grid-connected inverter control method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units described above are the same as in the corresponding embodiments described above, and will not be repeated here.

[0049] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0050] The following is a detailed reference. Figure 3The diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 001, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 002 or a program loaded from memory 008 into random access memory (RAM) 003. The RAM 003 also stores various programs and data required for the operation of the electronic device. The processor 001, ROM 002, and RAM 003 are interconnected via bus 004. An input / output (I / O) interface 005 is also connected to bus 004.

[0051] Typically, the following devices can be connected to I / O interface 005: input devices 006 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 007 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 008 including, for example, magnetic tapes, hard disks, etc.; and communication devices 009. Communication device 009 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 3 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0052] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication device 009, or installed from memory 008, or installed from ROM 002. When the computer program is executed by processor 001, it performs the functions defined in the three-phase grid-connected inverter control method of the embodiments of the present invention.

[0053] Figure 3 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0054] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the three-phase grid-connected inverter control method shown in the above embodiments is implemented.

[0055] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0056] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A control method for a three-phase grid-connected inverter, characterized in that, include: Based on the switching states and voltage and current parameters of the inverter's switching transistors, a prediction model for the AC side output current of a three-phase grid-connected inverter is established. Based on the current prediction model, a sequence of optimal predicted values ​​for future output current that meets the inverter performance indicators is obtained. Based on the optimal predicted value sequence of future output current and the inverter performance index, the optimal control quantity of the prediction model at the current moment is solved. The optimal control quantity at the current moment is obtained by inverse dq transformation to obtain the modulated wave signal at the current moment, and the control signal of the switching transistor is generated by using a preset modulation method.

2. The three-phase grid-connected inverter control method according to claim 1, characterized in that, The process of establishing a predictive model for the AC side output current of a three-phase grid-connected inverter includes: Based on the mathematical model of a three-phase grid-connected inverter in a three-phase stationary coordinate system, a linear mathematical model of the output current of the three-phase grid-connected inverter is established by using Clarke transform, Park transform, and feedforward decoupling. The linear mathematical model of inverter output current is discretized to obtain a controlled autoregressive integral moving average model of three-phase grid-connected inverter output current. Based on the controlled autoregressive integral moving average model, a prediction model for the AC output current of a three-phase grid-connected inverter is established by introducing the Diophantine equation.

3. The three-phase grid-connected inverter control method according to claim 2, characterized in that, The process of establishing a predictive model for the AC output current of a three-phase grid-connected inverter also includes: By using the recursive least squares method with diminishing memory, the polynomial parameters of the controlled autoregressive integral moving average model of the output current of a three-phase grid-connected inverter are obtained.

4. The three-phase grid-connected inverter control method according to claim 1, characterized in that, The process of obtaining the optimal predicted sequence of future output current values ​​that meet the inverter performance specifications includes: The difference between the inverter output current reference trajectory at the current moment and the inverter output current prediction value at the current moment is calculated to obtain the current difference. Based on the current difference and the optimal control increment of the inverter output current at the previous moment, an optimization equation for the performance index of the three-phase grid-connected inverter system is established. With the goal of minimizing the performance index of the three-phase grid-connected inverter system, the optimal prediction sequence of the future output current of the inverter is obtained.

5. The three-phase grid-connected inverter control method according to claim 4, characterized in that, The process of obtaining the inverter output current reference trajectory at the current moment includes: The current reference value is obtained by adjusting the difference between the bus voltage reference value and the actual bus voltage sample value through a PI controller. Based on the current reference value and the inverter output current at the previous moment, the reference trajectory of the inverter output current at the current moment is obtained.

6. The three-phase grid-connected inverter control method according to claim 4, characterized in that, The process of solving for the optimal control quantity of the prediction model at the current time includes: Obtain the partial derivative equations of the performance indicators of the three-phase grid-connected inverter system with respect to the control increment sequence; Setting the partial derivative equation to 0, we obtain the current time-optimal control increment of the prediction model in the control time domain; The sum of the optimal control increment at the current moment and the optimal control quantity at the previous moment is taken as the optimal control quantity at the current moment.

7. The three-phase grid-connected inverter control method according to claim 6, characterized in that, The formula for calculating the optimal control increment at the current moment includes an adaptive step factor. Therefore, the process of solving for the optimal control quantity at the current moment in the prediction model further includes: The adaptive step factor is calculated based on the inverter output current deviation and the initial value of the step factor. The adaptive step factor is used to increase the duty cycle of the inverter switching transistor when the inverter output current deviation is greater than a first preset threshold, and to decrease the duty cycle of the inverter switching transistor when the inverter output current deviation is less than a second preset threshold.

8. A three-phase grid-connected inverter control device, characterized in that, The device includes: The prediction model building module is used to build a prediction model of the AC side output current of a three-phase grid-connected inverter based on the switching state and voltage and current parameters of the inverter's switching transistors. The prediction module is used to obtain the optimal predicted value sequence of future output current that meets the inverter performance indicators based on the current prediction model. The solution module is used to solve for the optimal control quantity of the prediction model at the current moment based on the optimal prediction value sequence of the future output current of the inverter and the inverter performance index. The control module is used to obtain the current-time modulated wave signal by inverse dq transformation of the current-time optimal control quantity, and to generate the control signal of the switching transistor using a preset modulation method.

9. An electronic device, characterized in that, include: The system includes a memory and a processor, which are interconnected and communicate with each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the three-phase grid-connected inverter control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the three-phase grid-connected inverter control method according to any one of claims 1 to 7.

11. A computer program product, characterized in that, Includes computer instructions for causing a computer to execute the three-phase grid-connected inverter control method according to any one of claims 1 to 7.

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