Optimized voltage vector model prediction control method for three-level grid-connected inverter

Abstract

The invention discloses an optimized voltage vector model prediction control method, device and equipment for a three-level grid-connected inverter and a readable storage medium, and relates to the technical field of power system control. Comprising the following steps: firstly, acquiring an original voltage vector of the three-level grid-connected inverter, and optimizing the original voltage vector to obtain an optimized voltage vector; calculating the cost value of each optimized voltage vector according to a cost function, and selecting the optimized voltage vector with the minimum replacement value as a target voltage vector; and finally, determining a modulation signal of the three-level grid-connected inverter according to the target voltage vector, and controlling the three-level grid-connected inverter based on the modulation signal. The original voltage vector is optimized, so that better steady-state output current quality is achieved; and the starting point can move according to the optimized voltage vector at the previous moment, so that sudden change of the output voltage is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system control, in particular to an optimized voltage vector model predictive control method, device and equipment of three-level grid-connected inverter and readable storage medium. BACKGROUND

[0002] Three-level grid-connected inverters are increasingly widely used in power grids, but a series of problems have followed, such as complex control algorithm, current harmonic and midpoint voltage imbalance, which have promoted the continuous development of related control technology.

[0003] Early mainly adopts traditional PI and PR current controller, however, the controller parameter setting is complex, and the adjustment of parameters has great influence on system stability and power quality. In order to solve these problems, finite control set model predictive control (FCS-MPC) is more and more applied in grid-connected inverters. FCS-MPC has many advantages, such as simple structure, fast dynamic response and easy to realize multi-objective control, etc., but the voltage vector of three-level grid-connected inverter has 27, the traditional FCS-MPC method traverses these 27 voltage vectors in each cycle and selects the optimal voltage vector according to the cost function, which will cause the sudden change of output voltage, and is also inefficient in calculation. At low switching frequency, FCS-MPC will produce significant output ripple.

[0004] Therefore, an optimized voltage vector model predictive control method of three-level grid-connected inverter is needed to overcome the above defects. SUMMARY

[0005] The present application aims to provide an optimized voltage vector model predictive control method, device and equipment of three-level grid-connected inverter and readable storage medium, the original voltage vector is optimized, and the steady-state output current quality is better; and the starting point can be moved according to the optimized voltage vector of the previous moment, so as to avoid the sudden change of output voltage.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme: In the first aspect, the present application provides an optimized voltage vector model predictive control method of three-level grid-connected inverter, which comprises: Collecting the original voltage vector of the three-level grid-connected inverter, and optimizing the original voltage vector to obtain the optimized voltage vector; the optimization formula is: ; Among them, The current time is represented by the optimized voltage vector, and n 27 optimized voltage vectors are obtained. a target vector voltage of a last period, a raw voltage vector, a correlation degree of the voltage vector; calculating a cost value of each optimization voltage vector according to the cost function, and selecting an optimization voltage vector with a minimum cost value as a target voltage vector; determining a modulation signal of the three-level grid-connected inverter according to the target voltage vector, and controlling the three-level grid-connected inverter based on the modulation signal.

[0007] In some embodiments, determining the modulation signal of the three-level grid-connected inverter according to the target voltage vector comprises: normalizing the target voltage vector to obtain a reference modulation wave; determining a correction modulation wave based on the reference modulation wave and a zero sequence voltage corresponding to the target voltage vector; modulating the correction modulation wave by using a dual-carrier modulation strategy to obtain the modulation signal of the three-level grid-connected inverter.

[0008] In some embodiments, determining the correction modulation wave based on the reference modulation wave and the zero sequence voltage corresponding to the target voltage vector comprises: determining a target sector in which the target voltage vector is located; determining the correction modulation wave based on the reference modulation wave and a zero sequence voltage corresponding to the target sector.

[0009] In some embodiments, modulating the correction modulation wave by using the dual-carrier modulation strategy to obtain the modulation signal of the three-level grid-connected inverter comprises: generating two carriers; the carriers are triangular waves, and the carriers include a first triangular wave and a second triangular wave; an amplitude of the first triangular wave is -1-0, and an amplitude of the second triangular wave is 0-1; comparing the correction modulation wave with the first triangular wave and the second triangular wave to obtain the modulation signal of the three-level grid-connected inverter.

[0010] In some embodiments, comparing the correction modulation wave with the first triangular wave and the second triangular wave to obtain the modulation signal of the three-level grid-connected inverter comprises: when the correction modulation wave is greater than the first triangular wave and the second triangular wave, determining that the modulation signal of the three-level grid-connected inverter is to turn on a first switch and a second switch of the three-level grid-connected inverter and turn off a third switch and a fourth switch of the three-level grid-connected inverter; when the correction modulation wave is greater than the first triangular wave but less than the second triangular wave, determining that the modulation signal of the three-level grid-connected inverter is to turn on the second switch and the third switch of the three-level grid-connected inverter and turn off the first switch and the fourth switch of the three-level grid-connected inverter; When the corrected modulation wave is less than the first and second triangular waves, it is determined that the modulation signal of the three-level grid-connected inverter turns on the third and fourth switches of the three-level grid-connected inverter and turns off the first and second switches of the three-level grid-connected inverter.

[0011] In some embodiments, the method further comprises: Adjusting the relevance of the voltage vector according to a grid parameter of a target grid; the target grid is a grid to which the three-level grid-connected inverter is connected, and the grid parameter includes a grid frequency and an expected harmonic frequency range.

[0012] In a second aspect, the present application further provides an optimized voltage vector model predictive control device of a three-level grid-connected inverter, which comprises: a voltage optimization module, configured to collect original voltage vectors of the three-level grid-connected inverter and perform optimization processing on the original voltage vectors to obtain optimized voltage vectors; the optimization formula is: ; wherein, represents the optimized voltage vector at the current time point, n represents the target vector voltage at the last cycle, represents the original voltage vector, represents the relevance of the voltage vector; a voltage selection module, configured to calculate the cost value of each optimized voltage vector according to the cost function, and select the optimized voltage vector with the minimum cost value as the target voltage vector; a predictive control module, configured to determine the modulation signal of the three-level grid-connected inverter according to the target voltage vector, and control the three-level grid-connected inverter based on the modulation signal.

[0013] In a third aspect, the present application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the optimized voltage vector model predictive control method of the three-level grid-connected inverter provided in the first aspect when executing the computer program.

[0014] In a fourth aspect, the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the optimized voltage vector model predictive control method of the three-level grid-connected inverter provided in the first aspect.

[0015] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, and the computer program is executed by the processor to implement the optimized voltage vector model predictive control method of the three-level grid-connected inverter provided in the first aspect.

[0016] ​The beneficial effects of the present application are that: the optimization voltage vector model predictive control method of the three-level grid-connected inverter provided in the above embodiment first collects the original voltage vector of the three-level grid-connected inverter, and optimizes the original voltage vector to obtain an optimized voltage vector; then, the cost value of each optimized voltage vector is calculated according to a cost function, and the optimized voltage vector with the minimum cost value is selected as a target voltage vector; finally, the modulation signal of the three-level grid-connected inverter is determined according to the target voltage vector, and the three-level grid-connected inverter is controlled based on the modulation signal. The original voltage vector is optimized, and the steady-state output current quality is better; and the starting point can be moved according to the optimized voltage vector at the previous moment, so that sudden changes in the output voltage are avoided.

[0017] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and to implement the content of the specification, the following will be described in detail with the preferred embodiments of the present application and with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flowchart of an optimization voltage vector model predictive control method of a three-level grid-connected inverter according to an embodiment of the present application; Figure 2 A circuit diagram of a three-level grid-connected inverter according to an embodiment of the present application; Figure 3 A schematic diagram of sector division according to an embodiment of the present application; Figure 4 A schematic diagram of modulating a corrected modulation wave using a double carrier modulation strategy according to an embodiment of the present application; Figure 5 An output current waveform diagram of a limited control set model predictive control method according to an embodiment of the present application; Figure 6 An output waveform diagram of an optimization voltage vector model predictive control method of a three-level grid-connected inverter according to an embodiment of the present application; Figure 7 A bus capacitor voltage waveform diagram of a three-level grid-connected inverter according to an embodiment of the present application; Figure 8 A flowchart of another optimization voltage vector model predictive control method of a three-level grid-connected inverter according to an embodiment of the present application; Figure 9 A structural schematic diagram of an optimization voltage vector model predictive control device of a three-level grid-connected inverter according to an embodiment of the present application; Figure 10 A structural schematic diagram of another optimization voltage vector model predictive control device of a three-level grid-connected inverter according to an embodiment of the present application; Figure 11 This is a schematic diagram of an electronic device structure provided in an embodiment of this application. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0020] It should be noted that references to "an embodiment," "embodiment," "example embodiment," etc., in this specification refer to the described embodiment including specific features, structures, or characteristics; however, not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in conjunction with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0021] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] In some embodiments, such as Figure 1 As shown, an optimized voltage vector model predictive control method for a three-level grid-connected inverter is provided. The specific method includes: S101: Acquires the original voltage vector of the three-level grid-connected inverter and optimizes the original voltage vector to obtain the optimized voltage vector; Specifically, the optimized formula is as follows: ; in, Indicates the current time n An optimized voltage vector, This represents the target vector voltage of the previous cycle. Represents the original voltage vector. This indicates the correlation of voltage vectors.

[0023] For example. Figure 2 As shown, Figure 2 The circuit diagram of the three-level grid-connected inverter is shown. A voltage acquisition device can be used to acquire 27 original voltage vectors of the three-level grid-connected inverter, and these 27 original voltage vectors can be optimized according to the above formula (1) to obtain 27 optimized voltage vectors.

[0024] It should be noted that the voltage vector correlation can also be adjusted based on the grid parameters of the target grid. The target grid is the grid to which the three-level grid-connected inverter is connected, and the grid parameters include the grid frequency and the expected harmonic frequency range. A larger voltage vector correlation is beneficial for suppressing current ripple, but excessive voltage vector correlation may impair the output voltage and control performance response. Setting an appropriate voltage vector correlation has a crucial impact on the responsiveness of the control method. In practical applications, the voltage vector correlation can be adjusted and optimized according to the system's dynamic response and stability requirements.

[0025] S102, calculate the cost value of each optimized voltage vector according to the cost function, and select the optimized voltage vector with the smallest cost value as the target voltage vector.

[0026] Specifically, the cost function is: ; in, This represents the optimized voltage vector at the current moment. To optimize the cost of voltage vector, and Indicates the reference voltage.

[0027] For example, the 27 optimized voltage vectors are substituted into the above formula (2) to calculate the cost value of the 27 optimized voltage vectors. The 27 cost values ​​are compared numerically, and the optimized voltage vector corresponding to the minimum cost value is taken as the target voltage vector.

[0028] S103 determines the modulation signal of the three-level grid-connected inverter based on the target voltage vector, and controls the three-level grid-connected inverter based on the modulation signal.

[0029] Optionally, the target voltage vector can be normalized first to obtain the reference modulation wave; then, based on the zero-sequence voltage corresponding to the reference modulation wave and the target voltage vector, the correction modulation wave can be determined; finally, the correction modulation wave can be modulated using a dual-carrier modulation strategy to obtain the modulation signal of the three-level grid-connected inverter.

[0030] Specifically, after normalizing the target voltage vector to obtain the reference modulation wave, the target sector where the target voltage vector is located is first determined; then, based on the reference modulation wave and the zero-sequence voltage corresponding to the target sector, the correction modulation wave is determined.

[0031] For example, such as Figure 3 As shown, Figure 3 This is a schematic diagram of sector division, which can be based on... Figure 3 The target sector containing the target voltage vector is determined. Each sector corresponds to a zero-sequence voltage, as shown in Table 1.

[0032] in, This represents the three-phase output current of a three-level grid-connected inverter. Indicates the bus capacitance value. Indicates the control period. This represents the voltage across the bus capacitor. This represents the reference modulation wave for the three phases. This represents the zero-sequence voltage.

[0033] After determining the zero-sequence voltage corresponding to the target sector, the corrected modulation wave is calculated according to the following formula: ; in, Indicates the reference modulation wave, Represents zero-sequence voltage. This indicates the corrected modulation wave.

[0034] It should be noted that the correction modulation wave is a sine wave with an amplitude of -1 to 1, which can generate two carrier waves; the carrier waves are triangular waves, including a first triangular wave and a second triangular wave; the amplitude of the first triangular wave is -1 to 0, and the amplitude of the second triangular wave is 0 to 1; the correction modulation wave is compared with the first triangular wave and the second triangular wave to obtain the modulation signal of the three-level grid-connected inverter.

[0035] Specifically, such as Figure 4 As shown, Figure 4 The diagram illustrates the modulation of the correction modulation wave using a dual-carrier modulation strategy. When the correction modulation wave is greater than the first triangular wave and the second triangular wave, the modulation signal for the three-level grid-connected inverter is determined to be the conduction of the first switch (Sa1) and the second switch (Sa2) of the three-level grid-connected inverter, while the third switch (Sa3) and the fourth switch (Sa4) of the three-level grid-connected inverter are disconnected. When the correction modulation wave is greater than the first triangular wave but less than the second triangular wave, the modulation signal for the three-level grid-connected inverter is determined to be the conduction of the second switch and the third switch of the three-level grid-connected inverter, while the first switch and the fourth switch of the three-level grid-connected inverter are disconnected. When the correction modulation wave is less than the first triangular wave and the second triangular wave, the modulation signal for the three-level grid-connected inverter is determined to be the conduction of the third switch and the fourth switch of the three-level grid-connected inverter, while the first switch and the second switch of the three-level grid-connected inverter are disconnected.

[0036] Finally, the modulation signal of the three-level grid-connected inverter is input to the three-level grid-connected inverter to realize the control of the three-level grid-connected inverter.

[0037] The optimized voltage vector model predictive control method for a three-level grid-connected inverter in the above embodiments first acquires the original voltage vector of the three-level grid-connected inverter and optimizes it to obtain an optimized voltage vector. Then, it calculates the cost value of each optimized voltage vector based on a cost function and selects the optimized voltage vector with the lowest cost value as the target voltage vector. Finally, based on the target voltage vector, it determines the modulation signal of the three-level grid-connected inverter and controls the inverter based on the modulation signal. The optimized original voltage vector results in better steady-state output current quality; furthermore, the starting point can be moved based on the optimized voltage vector from the previous moment, thus avoiding sudden changes in the output voltage.

[0038] In another embodiment, the effectiveness of the method in this application was verified by controlling hardware-in-the-loop experiments, such as... Figure 5 and Figure 6 As shown, Figure 5 The output current waveform of the predictive control method using a finite control set model is shown. Figure 6 The output waveform of the optimized voltage vector model predictive control method for a three-level grid-connected inverter is shown. The results indicate that the optimized voltage vector model predictive control method for the three-level grid-connected inverter (i.e., the method in this application) can significantly reduce the total harmonic distortion (THD) of the output current from 5.85% to 1.54%. Figure 7 As shown, Figure 7 The waveform diagram shows the bus capacitor voltage of a three-level grid-connected inverter, indicating that the method in this application achieves neutral point voltage balance.

[0039] To more comprehensively demonstrate this solution, this embodiment presents an optional approach to an optimized voltage vector model predictive control method for a three-level grid-connected inverter, such as... Figure 8 As shown: S201, adjust the correlation of the voltage vector according to the grid parameters of the target grid.

[0040] The target power grid is the grid connected to a three-level grid-connected inverter, and the grid parameters include the grid frequency and the expected harmonic frequency range.

[0041] S202 acquires the original voltage vector of the three-level grid-connected inverter and optimizes the original voltage vector to obtain the optimized voltage vector.

[0042] S203, calculate the cost value of each optimized voltage vector according to the cost function, and select the optimized voltage vector with the smallest cost value as the target voltage vector.

[0043] S204 normalizes the target voltage vector to obtain the reference modulation wave.

[0044] S205, determine the target sector where the target voltage vector is located.

[0045] S206, determining a correction modulation wave based on the reference modulation wave and the zero sequence voltage corresponding to the target sector.

[0046] S207, generating two carriers.

[0047] The carrier is a triangular wave, and the carrier includes a first triangular wave and a second triangular wave; the amplitude of the first triangular wave is -1-0, and the amplitude of the second triangular wave is 0-1.

[0048] S208, comparing the correction modulation wave with the first triangular wave and the second triangular wave to obtain a modulation signal of the three-level grid-connected inverter.

[0049] Specifically, when the correction modulation wave is greater than the first triangular wave and the second triangular wave, it is determined that the modulation signal of the three-level grid-connected inverter is to turn on the first switch and the second switch of the three-level grid-connected inverter and turn off the third switch and the fourth switch of the three-level grid-connected inverter; when the correction modulation wave is greater than the first triangular wave but less than the second triangular wave, it is determined that the modulation signal of the three-level grid-connected inverter is to turn on the second switch and the third switch of the three-level grid-connected inverter and turn off the first switch and the fourth switch of the three-level grid-connected inverter; when the correction modulation wave is less than the first triangular wave and the second triangular wave, it is determined that the modulation signal of the three-level grid-connected inverter is to turn on the third switch and the fourth switch of the three-level grid-connected inverter and turn off the first switch and the second switch of the three-level grid-connected inverter.

[0050] S209, controlling the three-level grid-connected inverter based on the modulation signal.

[0051] The specific process of S201-S209 can be referred to the description of the above method embodiments, which has similar implementation principles and technical effects, and will not be described here.

[0052] Based on the same inventive concept, the embodiments of the present application also provide an optimization voltage vector model predictive control device for a three-level grid-connected inverter, which is used to implement the optimization voltage vector model predictive control method of the three-level grid-connected inverter. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more three-level grid-connected inverter optimization voltage vector model predictive control device embodiments provided below can be referred to the limitations of the three-level grid-connected inverter optimization voltage vector model predictive control method described above, and will not be described here.

[0053] In one embodiment, as shown in Figure 9 a three-level grid-connected inverter optimization voltage vector model predictive control device is provided, which includes: The voltage optimization module 30 is used to acquire the original voltage vector of the three-level grid-connected inverter and optimize the original voltage vector to obtain the optimized voltage vector; the optimization formula is: ; in, Indicates the current time n An optimized voltage vector, This represents the target vector voltage of the previous cycle. Represents the original voltage vector. Indicates the correlation of voltage vectors; The voltage selection module 31 is used to calculate the cost value of each optimized voltage vector according to the cost function, and select the optimized voltage vector with the minimum cost value as the target voltage vector. The predictive control module 32 is used to determine the modulation signal of the three-level grid-connected inverter based on the target voltage vector, and control the three-level grid-connected inverter based on the modulation signal.

[0054] In another embodiment, such as Figure 10 As shown above, Figure 9 The predictive control module 32 includes: The voltage processing unit 320 is used to normalize the target voltage vector to obtain a reference modulation wave; The waveform correction unit 321 is used to determine the correction modulation wave based on the zero-sequence voltage corresponding to the reference modulation wave and the target voltage vector; The signal determination unit 322 is used to modulate the correction modulation wave using a dual-carrier modulation strategy to obtain the modulation signal of the three-level grid-connected inverter.

[0055] In another embodiment, the above Figure 10 The waveform correction unit 321 includes: The sector determination sub-unit is used to determine the target sector where the target voltage vector is located; The waveform correction subunit is used to determine the correction modulation wave based on the reference modulation wave and the zero-sequence voltage corresponding to the target sector.

[0056] In another embodiment, the above Figure 10 The signal determination unit 322 in the middle includes: The carrier generation subunit is used to generate two carriers; the carriers are triangular waves, including a first triangular wave and a second triangular wave; the amplitude of the first triangular wave is -1 to 0, and the amplitude of the second triangular wave is 0 to 1. The waveform comparison subunit is used to compare the corrected modulation wave with the first triangular wave and the second triangular wave to obtain the modulation signal of the three-level grid-connected inverter.

[0057] In another embodiment, the waveform comparison subunit in the above embodiment is specifically used for: when the corrected modulation wave is greater than the first triangular wave and the second triangular wave, determining that the modulation signal of the three-level grid-connected inverter is to turn on the first and second switches of the three-level grid-connected inverter, and turning off the third and fourth switches of the three-level grid-connected inverter; when the corrected modulation wave is greater than the first triangular wave but less than the second triangular wave, determining that the modulation signal of the three-level grid-connected inverter is to turn on the second and third switches of the three-level grid-connected inverter, and turning off the first and fourth switches of the three-level grid-connected inverter; when the corrected modulation wave is less than the first triangular wave and the second triangular wave, determining that the modulation signal of the three-level grid-connected inverter is to turn on the third and fourth switches of the three-level grid-connected inverter, and turning off the first and second switches of the three-level grid-connected inverter.

[0058] In another embodiment, the above Figure 9 The optimized voltage vector model predictive control device for the three-level grid-connected inverter is also specifically used to: adjust the correlation of the voltage vector according to the grid parameters of the target grid; the target grid is the grid to which the three-level grid-connected inverter is connected, and the grid parameters include the grid frequency and the expected harmonic frequency range.

[0059] This application also provides an electronic device, in some embodiments, referring to... Figure 11 As shown, the electronic device 700 includes an input unit 710, a memory 720, a processor 730, and an output unit 740. The memory 720 stores program instructions that can run on the processor 730. The processor 730 can execute the optimized voltage vector model predictive control method and / or technical solution based on the three-level grid-connected inverter in the aforementioned embodiments by calling the program instructions. This electronic device 700 can be a mobile terminal device such as a mobile phone or computer.

[0060] Furthermore, embodiments of this application also provide a computer-readable storage medium for storing a computer program that executes an optimized voltage vector model predictive control method for a three-level grid-connected inverter. For example, computer program instructions, when executed by a computer, can invoke or provide the methods and / or technical solutions according to this application through the operation of the computer. The program instructions that invoke the methods of this application may be stored in a fixed or removable storage medium, and / or transmitted via data streams in broadcast or other signal carrying media, and / or stored in a storage medium that operates according to the program instructions.

[0061] Obviously, those skilled in the art should understand that the modules or steps of the present application described above can be realized by universal computing devices, and can be centralized on a single computing device or distributed on a network composed of multiple computing devices. Alternatively, they can be realized by program codes executable by the computing devices, so that they can be stored in storage devices and executed by the computing devices, or they can be respectively manufactured into individual integrated circuit modules, or multiple modules or steps among them can be manufactured into a single integrated circuit module to realize. Thus, the present application is not limited to any specific combination of hardware and software.

[0062] The technical features of the above embodiments can be integrated in any manner. In order to make the description simple, all possible integrations of the technical features in the above embodiments are not described, however, as long as the integration of the technical features does not exist contradictions, it should be considered as the scope of the present application.

[0063] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. An optimized voltage vector model predictive control method for a three-level grid-connected inverter, characterized in that, The method includes: The original voltage vector of the three-level grid-connected inverter is acquired and optimized to obtain the optimized voltage vector; the optimization formula is: ； in, Indicates the current time n An optimized voltage vector, This represents the target vector voltage of the previous cycle. Represents the original voltage vector. Indicates the correlation of voltage vectors; The cost value of each optimized voltage vector is calculated based on the cost function, and the optimized voltage vector with the smallest cost value is selected as the target voltage vector. Based on the target voltage vector, the modulation signal of the three-level grid-connected inverter is determined, and the three-level grid-connected inverter is controlled based on the modulation signal.

2. The optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in claim 1, characterized in that, Based on the target voltage vector, the modulation signal of the three-level grid-connected inverter is determined, including: The target voltage vector is normalized to obtain a reference modulation wave; Based on the reference modulation wave and the zero-sequence voltage corresponding to the target voltage vector, the correction modulation wave is determined; The correction modulation wave is modulated using a dual-carrier modulation strategy to obtain the modulation signal of the three-level grid-connected inverter.

3. The optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in claim 2, characterized in that, Based on the reference modulation wave and the zero-sequence voltage corresponding to the target voltage vector, the corrected modulation wave is determined, including: Determine the target sector where the target voltage vector is located; The corrected modulation wave is determined based on the reference modulation wave and the zero-sequence voltage corresponding to the target sector.

4. The optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in claim 2, characterized in that, The correction modulation wave is modulated using a dual-carrier modulation strategy to obtain the modulation signal of the three-level grid-connected inverter, including: Two carrier waves are generated; the carrier waves are triangular waves, including a first triangular wave and a second triangular wave; the amplitude of the first triangular wave is -1 to 0, and the amplitude of the second triangular wave is 0 to 1. The correction modulation wave is compared with the first triangular wave and the second triangular wave to obtain the modulation signal of the three-level grid-connected inverter.

5. The optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in claim 4, characterized in that, The correction modulation wave is compared with the first triangular wave and the second triangular wave to obtain the modulation signal of the three-level grid-connected inverter, including: When the correction modulation wave is greater than the first triangular wave and the second triangular wave, the modulation signal of the three-level grid-connected inverter is determined to turn on the first and second switches of the three-level grid-connected inverter and turn off the third and fourth switches of the three-level grid-connected inverter. When the correction modulation wave is greater than the first triangular wave but less than the second triangular wave, the modulation signal of the three-level grid-connected inverter is determined to turn on the second and third switches of the three-level grid-connected inverter and turn off the first and fourth switches of the three-level grid-connected inverter. When the correction modulation wave is smaller than the first triangular wave and the second triangular wave, the modulation signal of the three-level grid-connected inverter is determined to turn on the third and fourth switches of the three-level grid-connected inverter and turn off the first and second switches of the three-level grid-connected inverter.

6. The optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in claim 1, characterized in that, The method further includes: The correlation of the voltage vector is adjusted according to the grid parameters of the target grid; the target grid is the grid to which the three-level grid-connected inverter is connected, and the grid parameters include the grid frequency and the expected harmonic frequency range.

7. An optimized voltage vector model predictive control device for a three-level grid-connected inverter, characterized in that, The device includes: The voltage optimization module is used to acquire the original voltage vector of the three-level grid-connected inverter and optimize the original voltage vector to obtain the optimized voltage vector; the optimization formula is: ； in, Indicates the current time n An optimized voltage vector, This represents the target vector voltage of the previous cycle. Represents the original voltage vector. Indicates the correlation of voltage vectors; The voltage selection module is used to calculate the cost value of each optimized voltage vector according to the cost function, and select the optimized voltage vector with the minimum cost value as the target voltage vector. The predictive control module is used to determine the modulation signal of the three-level grid-connected inverter based on the target voltage vector, and control the three-level grid-connected inverter based on the modulation signal.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the optimized voltage vector model predictive control method for the three-level grid-connected inverter as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the optimized voltage vector model predictive control method for a three-level grid-connected inverter as described in any one of claims 1 to 6.

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