A grid-connected inverter control method and system based on quasi-proportional-resonant
By improving the control technology of grid-connected inverters through quasi-proportional resonant control and dual-loop current feedback mechanisms, the problems of harmonic suppression and slow dynamic response speed are solved, thereby enhancing the stability and reliability of the power system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QUJING POWER SUPPLY BUREAU YUNNAN POWER GRID CO LTD
- Filing Date
- 2024-03-29
- Publication Date
- 2026-07-21
Smart Images
Figure CN122437111A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of grid-connected inverter control technology, and in particular to a grid-connected inverter control method and system based on quasi-proportional resonance. Background Technology
[0002] Society today faces growing contradictions in the energy sector. With the increasing demand for clean energy, especially renewable energy, traditional energy supply models can no longer meet people's pursuit of environmental protection and efficient energy. However, as a core component of renewable energy power generation systems, the control technology of grid-connected inverters is particularly important in the current social context.
[0003] Currently, existing grid-connected inverter control technologies have some shortcomings, such as insufficient flexibility in handling harmonic frequencies in the power grid, making it difficult to effectively suppress the impact of harmonics on the grid; slow dynamic response speed of the controller, making it difficult to meet the power grid's power quality requirements; and traditional control schemes also pose certain challenges to stability and reliability during grid faults. The technical solution of this invention adopts a quasi-proportional resonance-based control method. By improving the design of existing controllers and introducing new technologies such as harmonic compensation controllers and dual-loop current feedback mechanisms, it effectively improves the control accuracy, dynamic performance, and stability of grid-connected inverters, thereby better meeting the power system's demand for clean energy and promoting the sustainable development of energy transition and power supply. Summary of the Invention
[0004] In view of the problems existing in the control methods and systems of grid-connected inverters based on quasi-proportional resonance, this invention is proposed.
[0005] Therefore, the purpose of this invention is to provide a grid-connected inverter control method and system based on quasi-proportional resonance. To address the shortcomings of existing technologies in terms of harmonic suppression, dynamic response speed, and stability, this invention employs a quasi-proportional resonance control method and a dual-loop current feedback mechanism.
[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:
[0007] In a first aspect, embodiments of the present invention provide a grid-connected inverter control method based on quasi-proportional resonance, which includes: making a judgment based on the calculation formulas of the PI controller and the PR controller; improving the PR control technology by adopting quasi-PR control technology; analyzing the parameters within the quasi-PR control technology; and designing the inverter quasi-PR control based on the analysis results.
[0008] As a preferred embodiment of the grid-connected inverter control method based on quasi-proportional resonance described in this invention, the judgment includes extracting and comparing the same parameter values from the PI controller and the PR controller. The extraction includes calculating the transfer functions of the PI controller and the PR controller. The specific steps are as follows:
[0009] The formula for calculating the transfer function of a PI controller is as follows:
[0010]
[0011] Among them, K p Indicates proportional adjustment, K i Indicates the integral coefficient;
[0012] The formula for calculating the transfer function of the PR controller is as follows:
[0013]
[0014] Among them, K R K represents the resonance coefficient. i =K R ;
[0015] Draw Bode plots for both PI and PR controllers, and make judgments based on the harmonic frequencies of the Bode plots. The specific steps are as follows:
[0016] When the harmonic frequency is s, the gain of the PR controller is greater than the gain of the PI controller.
[0017] When the harmonic frequency is greater than s, the gain of the PR controller is equal to the gain of the PI controller.
[0018] When the harmonic frequency is less than s, the gain of the PR controller is less than the gain of the PI controller.
[0019] As a preferred embodiment of the grid-connected inverter control method based on quasi-proportional resonance described in this invention, the PR controller further includes using a PR control strategy to compensate for harmonic frequencies, defining a harmonic compensation controller, and combining the harmonic compensation controller with the proportional resonance controller. The specific steps are as follows:
[0020] The specific calculation formula for the defined harmonic compensation controller is as follows:
[0021]
[0022] Where h represents the harmonic order, K h Controller parameters representing different harmonics;
[0023] The specific formula for combining the harmonic compensation controller and the proportional resonant controller is as follows:
[0024]
[0025] Where w0 represents the fundamental frequency, K R K represents the resonance coefficient. h The controller parameters represent different harmonics, where h represents the harmonic order.
[0026] As a preferred embodiment of the grid-connected inverter control method based on quasi-proportional resonance described in this invention, the improvement includes adding zero-point calculations to the PR controller based on the extracted parameter values to obtain the quasi-PR controller transfer function, and the specific calculation formula is as follows:
[0027]
[0028] Wherein, the fundamental frequency w0 = 314.15 rad / sec, γ represents the correlation coefficient between the cutoff frequency and the resonant frequency, and the Bode plot of QPR is obtained based on the transfer function of the quasi-PR controller.
[0029] As a preferred embodiment of the grid-connected inverter control method based on quasi-proportional resonance described in this invention, the analysis includes fixing the variables in the quasi-PR controller transfer function using the fixed variable method based on the Bode plot of the QPR, and comparing and analyzing the impact of changing one parameter on the controller Bode plot. The specific steps are as follows:
[0030] When controlling K R When γ and K are both present, then K p If K changes p As the gain increases, the system gain also increases, and the two are directly proportional, while the system's resonant peak value remains unchanged.
[0031] When controlling K p When γ and K are both present, then K R If K changes R As the value increases, the system's resonant peak value continuously increases, and the system's bandwidth also increases.
[0032] When controlling K p and K R When γ increases, γ changes. If γ continues to increase, the system gain remains unchanged, the resonant peak value remains unchanged, and the system bandwidth increases.
[0033] As a preferred embodiment of the quasi-proportional resonance-based grid-connected inverter control method of the present invention, the design includes controlling the grid-connected current in the αβ stationary coordinate system based on variable analysis results. The control includes introducing a dual-loop current feedback mechanism with the filter capacitor current as the inner loop and the grid current as the outer loop. The reactive power of the system is calculated according to the equivalent control block diagram of the LCL grid-connected inverter controlled by QPR. Based on the reactive power, the open-loop transfer function from the reference signal to the filter current and the closed-loop transfer function from the reference current to the grid current are calculated. The specific steps are as follows:
[0034] The specific formula for calculating the reactive power is as follows:
[0035] Q = 1.5 × (-1u) gβ i ckα +u gβ i ckβ )
[0036] Where Q represents the reactive power of the system, let as well as
[0037] The specific formula for the open-loop transfer function is as follows:
[0038]
[0039] The specific formula for calculating the closed-loop transfer function is as follows:
[0040]
[0041] Where A(s)=G QPR (s)K PWM-k G Lk1 (s)+G Lk1 (s)G C (s)+G QPR (s)K PWM-k G Lk1 (s)G c (s)G Lk2 (s).
[0042] As a preferred embodiment of the grid-connected inverter control method based on quasi-proportional resonance described in this invention, the design further includes determining, based on the calculation results of the open-loop transfer function and the closed-loop transfer function, that there is no amplitude or phase error between the input current and the output current, thus the system has a fast dynamic response and good dynamic performance.
[0043] Secondly, embodiments of the present invention provide a grid-connected inverter control system based on quasi-proportional resonance, which includes: a judgment module, which makes judgments based on the calculation formulas of the PI controller and the PR controller, and improves the PR control technology by adopting quasi-PR control technology;
[0044] The control module analyzes the parameters within the quasi-PR control technology and designs the quasi-PR control for the inverter based on the analysis results.
[0045] Thirdly, embodiments of the present invention provide a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement any step of the above-described grid-connected inverter control method based on quasi-proportional resonance.
[0046] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any step of the above-described grid-connected inverter control method based on quasi-proportional resonance.
[0047] The beneficial effects of this invention are as follows: This invention employs a quasi-proportional resonant control method and a harmonic compensation controller, effectively suppressing harmonics in the inverter output, improving the grid-connected inverter's compatibility with the power grid, reducing harmonic damage to grid equipment and interference to the power system, and enhancing the stability and reliability of the power system. The introduction of a dual-loop current feedback mechanism optimizes the inverter's dynamic response speed, enabling it to quickly and stably adjust the output current under sudden events such as grid faults, effectively improving the system's dynamic performance and response speed. Furthermore, this invention further improves the inverter's control accuracy and stability through optimized design of the quasi-proportional resonant controller parameters, ensuring good performance under various operating conditions. Attached Figure Description
[0048] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:
[0049] Figure 1 The following is a detailed flowchart of a grid-connected inverter control method and system based on quasi-proportional resonance, provided as an embodiment of the present invention.
[0050] Figure 2 A different K-line of the grid-connected inverter control method and system based on quasi-proportional resonance provided in one embodiment of the present invention. P Bode plot of the QPR controller. Detailed Implementation
[0051] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0052] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0053] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.
[0054] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.
[0055] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0056] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0057] Example 1
[0058] Reference Figures 1-2 This is the first embodiment of the present invention, which provides a grid-connected inverter control method based on quasi-proportional resonance, including:
[0059] S1: Based on the calculation formulas of the PI controller and PR controller, a judgment is made, and the PR control technology is improved by adopting quasi-PR control technology.
[0060] The process includes comparing identical parameter values extracted from the PI and PR controllers, and calculating the transfer functions of the PI and PR controllers. The specific steps are as follows:
[0061] The formula for calculating the transfer function of a PI controller is as follows:
[0062]
[0063] Among them, K p Indicates proportional adjustment, K i Indicates the integral coefficient;
[0064] The formula for calculating the transfer function of the PR controller is as follows:
[0065]
[0066] Among them, K R K represents the resonance coefficient. i =K R ;
[0067] Draw Bode plots for both PI and PR controllers, and make judgments based on the harmonic frequencies of the Bode plots. The specific steps are as follows:
[0068] When the harmonic frequency is s, the gain of the PR controller is greater than the gain of the PI controller.
[0069] When the harmonic frequency is greater than s, the gain of the PR controller is equal to the gain of the PI controller.
[0070] When the harmonic frequency is less than s, the gain of the PR controller is less than the gain of the PI controller.
[0071] Furthermore, when calculating the controller's transfer function, 's' can be replaced with a specific harmonic frequency value of 50Hz or 60Hz for calculation. The harmonic frequency values are compared in Table 1 below:
[0072] Table 1 Comparison of Harmonic Frequency Values
[0073] First harmonic 50 Second harmonic 100 Third harmonic 150 Fourth harmonic 200 Fifth harmonic 250
[0074] The table shows several possible harmonic frequency values, including the first, second, and third harmonics. These values are usually multiples of the power system's fundamental frequency, such as 50Hz or 60Hz. By comparing different harmonic frequency values, the system's performance and stability at different frequencies, as well as the effectiveness of the controller, can be evaluated.
[0075] S1.1: The PR controller also includes harmonic frequency compensation using a PR control strategy. A harmonic compensation controller is defined, and it is combined with a proportional resonant controller. The specific steps are as follows:
[0076] The specific calculation formula for the harmonic compensation controller is defined as follows:
[0077]
[0078] Where h represents the harmonic order, K h Controller parameters representing different harmonics;
[0079] The specific formula for combining the harmonic compensation controller with the proportional resonant controller is as follows:
[0080]
[0081] Where w0 represents the fundamental frequency, K R K represents the resonance coefficient. h The controller parameters represent different harmonics, where h represents the harmonic order.
[0082] S1.2: The improvement includes adding zero-point calculation to the PR controller based on the extracted parameter values to obtain the quasi-PR controller transfer function. The specific calculation formula is as follows:
[0083]
[0084] Wherein, the fundamental frequency w0 = 314.15 rad / sec, γ represents the correlation coefficient between the cutoff frequency and the resonant frequency, and the Bode plot of QPR is obtained based on the transfer function of the quasi-PR controller.
[0085] S2: Analyze the parameters within the quasi-PR control technology, and design the inverter quasi-PR control based on the analysis results.
[0086] The analysis includes fixing the variables in the quasi-PR controller transfer function using the fixed variable method based on the Bode plot of the QPR, changing one parameter, and comparing the impact of the parameter change on the controller's Bode plot. The specific steps are as follows:
[0087] When controlling K R When γ and K are both present, then K p If K changes pAs the gain increases, the system gain also increases, and the two are directly proportional, while the system's resonant peak value remains unchanged.
[0088] When controlling K p When γ and K are both present, then K R If K changes R As the value increases, the system's resonant peak value continuously increases, and the system's bandwidth also increases.
[0089] When controlling K p and K R When γ increases, γ changes. If γ continues to increase, the system gain remains unchanged, the resonant peak value remains unchanged, and the system bandwidth increases.
[0090] When controlling K R When γ = 400 and γ = 0.01, then K p If K changes p As the gain increases, the system gain also increases, and the two are directly proportional, while the system's resonant peak value remains unchanged.
[0091] When controlling K p When γ = 10 and γ = 0.01, then K R If K changes R As the value increases, the system's resonant peak value continuously increases, and the system's bandwidth also increases.
[0092] When controlling K p =10 and K R When γ = 400, γ changes. If γ continues to increase, the system gain remains unchanged, the resonant peak value remains unchanged, and the system bandwidth increases. The data on the influence of the control variables on the system performance are shown in Table 2 below:
[0093] Table 2. Data on the impact of control variables on system performance
[0094]
[0095] The table shows the changes in system performance under different control variables. By comparing the changes in the system's resonant peak value and bandwidth when the control variables take different values, including the integral coefficient and proportional modulation, the system's performance parameters will be different under different control variables. This shows that the choice of control variables has an important impact on system performance.
[0096] S2.1: The design includes controlling the grid-connected current in the αβ stationary coordinate system based on the results of variable analysis. The control mechanism includes a dual-loop current feedback mechanism with the filter capacitor current as the inner loop and the grid current as the outer loop. The reactive power of the system is calculated based on the equivalent control block diagram of the LCL grid-connected inverter controlled by QPR. Based on the reactive power, the open-loop transfer function from the reference signal to the filter current and the closed-loop transfer function from the reference current to the grid-connected current are calculated. The specific steps are as follows:
[0097] The specific formula for calculating reactive power is:
[0098] Q = 1.5 × (-u) gβ i ckα +u gβ i ckβ )
[0099] Where Q represents the reactive power of the system, let as well as
[0100] The specific formula for the open-loop transfer function is:
[0101]
[0102] The specific formula for calculating the closed-loop transfer function is as follows:
[0103]
[0104] Where: A(s) = G QPR (s)K PWM-k G Lk1 (s)+G Lk1 (s)G C (s)+G QPR (s)K PWM-k G Lk1 (s)G C (s)G Lk2 (s).
[0105] Furthermore, the design also includes calculations based on the open-loop and closed-loop transfer functions to determine that there are no amplitude or phase errors between the input and output currents, thus ensuring that the system has a fast dynamic response and good dynamic performance.
[0106] In a preferred embodiment, a grid-connected inverter control method and system based on quasi-proportional resonance is provided. The system includes a judgment module that makes judgments based on the calculation formulas of the PI controller and the PR controller, and improves the PR control technology by adopting quasi-PR control technology.
[0107] The control module analyzes the parameters within the quasi-PR control technology and designs the quasi-PR control for the inverter based on the analysis results.
[0108] The above-mentioned unit modules can be embedded in the processor of the computer device in hardware form or independent of it, or they can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of the above modules.
[0109] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.
[0110] In summary, this invention employs a quasi-proportional resonant control method and a harmonic compensation controller, effectively suppressing harmonics in the inverter output, improving the grid-connected inverter's compatibility with the power grid, reducing harmonic damage to grid equipment and interference to the power system, and enhancing the stability and reliability of the power system. The introduction of a dual-loop current feedback mechanism optimizes the inverter's dynamic response speed, enabling it to quickly and stably adjust the output current under sudden events such as grid faults, effectively improving the system's dynamic performance and response speed. Furthermore, this invention further improves the inverter's control accuracy and stability through optimized design of the quasi-proportional resonant controller parameters, ensuring good performance under various operating conditions.
[0111] Example 2
[0112] Reference Figures 1-2 This is the second embodiment of the present invention, which provides a grid-connected inverter control method based on quasi-proportional resonance. In order to verify the beneficial effects of the present invention, a simulation experiment is conducted for scientific demonstration.
[0113] Multiple sets of data are collected and compared to evaluate the performance of the grid-connected inverter system. Data such as current, voltage, power, harmonic content, and dynamic response speed are recorded and compared under different control variable conditions. When the control variable is K... i =0.01, K pWhen the value is 400, the observed current is 100A, voltage is 220V, power is 22kW, harmonic content is 5%, and dynamic response speed is 10ms; while when the control variable is K i =0.01, K p When the value is 10, these data are 120A, 210V, 20kW, 8%, and 15ms respectively; when the control variable is K i =400, K p When the value is 0.01, the data are 90A, 230V, 25kW, 3%, and 8ms. These specific values will help to better understand the working state and performance of the grid-connected inverter system under different control conditions, and provide an important reference for system optimization. The experimental data comparison is shown in Table 3 below:
[0114] Table 3 Comparison of Experimental Data
[0115] Ki = 0.01, Kp = 400 100 220 22 5 10 Ki = 0.01, Kp = 10 120 210 20 8 15 Ki = 400, Kp = 0.01 90 230 25 3 8
[0116] The table summarizes the experimental data under different control variable conditions. By comparing parameters such as current, voltage, power, harmonic content, and dynamic response speed, the differences in system performance under different control conditions are clearly shown. A comparison with existing technologies is shown in Table 4 below:
[0117] Table 4 Comparison with Existing Technologies
[0118] Control methods Based on PI and PR controllers Control methods based on quasi-PR control technology Parameter adjustment method Manual adjustment or fixed parameters Automatically adjust parameters based on experimental data Harmonic suppression effect Generally, parameters need to be adjusted manually. Better harmonic suppression effect Dynamic response performance Generally, parameters need to be adjusted manually. Faster dynamic response performance System stability Relying on experience and manual adjustments Provides more stable system operation The difficulty of the optimization scheme It's quite complex and requires specialized knowledge. Simpler, relying on automated algorithms
[0119] The table highlights the advantages of this invention over existing technologies. Compared to existing technologies, this invention employs an improved method based on quasi-PR control technology, resulting in better harmonic suppression and faster dynamic response performance. Furthermore, this technology enables automatic parameter adjustment, making the system more stable and simplifying the implementation of optimization schemes.
[0120] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A grid-connected inverter control method based on quasi-proportional resonance, characterized in that: include, Judgment is made based on the calculation formulas of PI controller and PR controller, and quasi-PR control technology is used to improve PR control technology; The parameters within the quasi-PR control technology are analyzed, and the quasi-PR control of the inverter is designed based on the analysis results.
2. The grid-connected inverter control method based on quasi-proportional resonance as described in claim 1, characterized in that: The judgment includes extracting and comparing the same parameter values from the PI controller and the PR controller. The extraction includes calculating the transfer functions of the PI controller and the PR controller. The specific steps are as follows: The formula for calculating the transfer function of the PI controller is as follows: Among them, K p Indicates proportional adjustment, K i Indicates the integral coefficient; The formula for calculating the transfer function of the PR controller is as follows: Among them, K R K represents the resonance coefficient. i =K R ; Draw Bode plots for both PI and PR controllers, and make judgments based on the harmonic frequencies of the Bode plots. The specific steps are as follows: When the harmonic frequency is s, the gain of the PR controller is greater than the gain of the PI controller. When the harmonic frequency is greater than s, the gain of the PR controller is equal to the gain of the PI controller. When the harmonic frequency is less than s, the gain of the PR controller is less than the gain of the PI controller.
3. The grid-connected inverter control method based on quasi-proportional resonance as described in claim 2, characterized in that: The PR controller also includes harmonic frequency compensation using a PR control strategy, defining a harmonic compensation controller, and combining the harmonic compensation controller with a proportional resonant controller. The specific steps are as follows: The specific calculation formula for the defined harmonic compensation controller is as follows: Where h represents the harmonic order, K h Controller parameters representing different harmonics; The specific formula for combining the harmonic compensation controller and the proportional resonant controller is as follows: Where w0 represents the fundamental frequency, K R K represents the resonance coefficient. h The controller parameters represent different harmonics, where h represents the harmonic order.
4. The grid-connected inverter control method based on quasi-proportional resonance as described in claim 3, characterized in that: The improvement includes adding zero-point calculation to the PR controller based on the extracted parameter values to obtain the quasi-PR controller transfer function. The specific calculation formula is as follows: Wherein, the fundamental frequency w0 = 314.15 rad / sec, γ represents the correlation coefficient between the cutoff frequency and the resonant frequency, and the Bode plot of QPR is obtained based on the transfer function of the quasi-PR controller.
5. The grid-connected inverter control method based on quasi-proportional resonance as described in claim 4, characterized in that: The analysis includes fixing the variables in the quasi-PR controller transfer function using the fixed variable method based on the Bode plot of the QPR, changing one parameter, and comparing the impact of the parameter change on the controller's Bode plot. The specific steps are as follows: When controlling K R When γ and K are both present, then K p If K changes p As the gain increases, the system gain also increases, and the two are directly proportional, while the system's resonant peak value remains unchanged. When controlling K p When γ and K are both present, then K R If K changes R As the value increases, the system's resonant peak value continuously increases, and the system's bandwidth also increases. When controlling K p and K R When γ increases, γ changes. If γ continues to increase, the system gain remains unchanged, the resonant peak value remains unchanged, and the system bandwidth increases.
6. The grid-connected inverter control method based on quasi-proportional resonance as described in claim 5, characterized in that: The design includes controlling the grid-connected current in the αβ stationary coordinate system based on variable analysis results. This control includes a dual-loop current feedback mechanism, introducing the filter capacitor current as the inner loop and the grid current as the outer loop. The reactive power of the system is calculated based on the equivalent control block diagram of the LCL grid-connected inverter controlled by QPR. Based on the reactive power, the open-loop transfer function from the reference signal to the filter current and the closed-loop transfer function from the reference current to the grid-connected current are calculated. The specific steps are as follows: The specific formula for calculating the reactive power is as follows: Q=1.5×(-u gβ i ckα +u gβ i ckβ ) Where Q represents the reactive power of the system, let as well as The specific formula for the open-loop transfer function is as follows: The specific formula for calculating the closed-loop transfer function is as follows: where A(s) = G QPR (s)K PWM-k G Lk1 (s)+G Lk1 (s)G C (s+G QPR (s)K PWM-k G Lk1 (s)G C (s)G Lk2 (s).
7. The grid-connected inverter control method based on quasi-proportional resonance as described in claim 6, characterized in that: The design also includes determining, based on the calculation results of the open-loop transfer function and the closed-loop transfer function, that there is no amplitude or phase error between the input current and the output current, thus the system has a fast dynamic response and good dynamic performance.
8. A grid-connected inverter control system based on quasi-proportional resonance, based on the grid-connected inverter control method based on quasi-proportional resonance according to any one of claims 1 to 7, characterized in that: include, The judgment module makes judgments based on the calculation formulas of the PI controller and the PR controller, and improves the PR control technology by adopting quasi-PR control technology; The control module analyzes the parameters within the quasi-PR control technology and designs the quasi-PR control for the inverter based on the analysis results.
9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the grid-connected inverter control method based on quasi-proportional resonance as described in any one of claims 1 to 7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the grid-connected inverter control method based on quasi-proportional resonance as described in any one of claims 1 to 7.