Converter network following control method, system and device and storage medium
By acquiring the parameters of the converter and the grid-side line, and using a preset optimization model to adjust the control mode of the converter, the problems of transient performance degradation and resonance instability in the converter-grid control are solved, and adaptive, efficient and stable grid-connected control is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-04-10
AI Technical Summary
During grid-connected control, the converter is affected by changes in grid-side line impedance, leading to a decline in transient performance and resonant instability, which threatens the stable operation of the power grid.
By acquiring the converter's specifications and the grid-side line equivalent impedance, and combining the set reference values of the d-axis and q-axis current components, the target control mode is adjusted in real time using a preset optimization model to optimize the on and off states of the switching transistors, thereby achieving adaptive grid-following control.
Under varying converter operating conditions, the optimal target control method was achieved, avoiding control performance degradation and resonance instability, and ensuring efficient and stable grid connection of new energy sources.
Smart Images
Figure CN121840752A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of converter control technology, and in particular to a converter grid control method, system, device and storage medium. Background Technology
[0002] Converters based on power electronic devices are one of the key devices for grid connection of new energy sources. Specifically, the DC power generated by new energy power generation can be converted into AC power by the converter and connected to the power grid. By relying on the set control mode, grid-connected control can be achieved, and the output current of the converter can be adjusted to follow the set reference value.
[0003] Currently, the main control method for converters to achieve grid-connected control is based on the current loop control structure and proportional-integral control strategy, which sets the loop bandwidth of the current loop to one-tenth of the switching frequency. However, due to the influence of changes in grid-side line impedance, the transient performance of converter grid-connected control may decline, and there is even a probability of resonance, which leads to deterioration of power quality and threatens the stable operation of the power grid. Summary of the Invention
[0004] The problem solved by this invention is to provide a converter grid control method, system, device and storage medium, which facilitates real-time adjustment under changing converter operating conditions to determine the optimal target control mode and avoids control performance degradation and resonance instability.
[0005] To address the aforementioned technical problems, this application provides a converter grid connection control method, comprising: Obtain the specifications of the converter and the equivalent impedance of the grid-side lines; Obtain the first set reference value corresponding to the d-axis current component and the second set reference value corresponding to the q-axis current component on the output grid side of the converter; When it is determined that the operating condition of the converter has changed, the details of the change in operating condition are determined. The inherent control mode, the specified parameters, the equivalent impedance, and the operating condition changes are input into a preset optimization model to obtain an optimized target control mode. This optimized target control mode is then used to control the switching transistors in the converter to turn on and off, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value.
[0006] The beneficial effects of this invention are as follows: Based on the preset optimization model and input item settings, this scheme is conducive to real-time adjustment under the changing conditions of the converter to determine the optimal target control mode, thereby realizing adaptive grid-following control, avoiding control performance degradation and resonance instability, ensuring the efficient and stable grid connection of new energy sources, and facilitating practical applications.
[0007] Furthermore, the changes in operating conditions include changes in the specification parameters, and / or changes in the equivalent impedance, and / or changes in the first set reference value corresponding to the d-axis current component, and / or changes in the second set reference value corresponding to the q-axis current component.
[0008] Furthermore, the preset optimization model is deployed on a server terminal with edge computing capabilities.
[0009] Furthermore, the inherent control method, the specified parameters, the equivalent impedance, and the operating condition changes are used as inputs into a preset optimization model to obtain the optimized target control method, including: Encapsulate the control code corresponding to the inherent control method into a DLL file; The DLL file is uploaded to the server terminal through the application programming interface of the preset optimization model, so as to input the DLL file into the preset optimization model; The specified parameters, the equivalent impedance, and the operating condition changes are input into the preset optimization model to obtain the optimized target control mode.
[0010] Furthermore, the inherent control method includes an inherent control structure, an inherent control strategy, and the values of control parameters under the inherent control strategy; The target control method includes the optimized values of the control parameters.
[0011] Furthermore, the target control method also includes an optimized optimal control structure and / or an optimal control strategy.
[0012] Furthermore, the preset optimization model is LLM.
[0013] To address the aforementioned technical problems, this application also provides a converter-grid connection control system, comprising: The first acquisition unit is used to acquire the specifications of the converter and the equivalent impedance of the grid-side lines; The second acquisition unit is used to acquire the first set reference value corresponding to the d-axis current component and the second set reference value corresponding to the q-axis current component on the output grid side of the converter. The operating condition change determination unit is used to determine the operating condition change when it is determined that the operating condition of the converter has changed. The optimization unit is used to input the inherent control mode, the specification parameters, the equivalent impedance, and the operating condition changes as input items into a preset optimization model to obtain an optimized target control mode. This optimized target control mode is then used to control the switching transistors in the converter to turn on and off, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value.
[0014] To address the aforementioned technical problems, this application also provides a converter grid connection control device, comprising: Memory, used to store computer programs; A processor is used to execute the computer program to implement the steps of the converter and grid control method as described above.
[0015] To address the aforementioned technical problems, this application also provides a computer storage medium storing a computer program, which, when executed by a processor, implements the steps of the converter-grid control method described above. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A flowchart of a converter grid control method provided by the present invention; Figure 2 A schematic diagram illustrating transient performance comparison provided by the present invention; Figure 3 This invention provides another schematic diagram for comparing transient performance. Figure 4 A schematic diagram illustrating the comparison of resonance suppression effects provided by this invention; Figure 5 This invention provides a schematic diagram of the structure of a converter and grid control system. Figure 6 This is a schematic diagram of the structure of a converter and grid control device provided by the present invention. Detailed Implementation
[0017] The core of this invention is to provide a converter grid control method, system, device, and storage medium, which facilitates real-time adjustment under changing converter operating conditions to determine the optimal target control mode and avoids control performance degradation and resonance instability.
[0018] 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.
[0019] Please refer to Figure 1 , Figure 1 A flowchart of a converter-grid control method provided by the present invention.
[0020] The converter's grid control method includes: S11: Obtain the specifications of the converter and the equivalent impedance of the grid-side lines; S12: Obtain the first set reference value corresponding to the d-axis current component and the second set reference value corresponding to the q-axis current component on the output grid side of the converter; S13: When it is determined that the operating conditions of the converter have changed, determine the changes in operating conditions; S14: Input the inherent control mode, specification parameters, equivalent impedance, and operating condition changes into the preset optimization model to obtain the optimized target control mode. Then, control the switching transistors in the converter to turn on and off based on the target control mode, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value.
[0021] Specifically, the DC power supply is connected to the input terminal of the converter, and the output terminal of the converter is connected to the power grid through the grid-side line. The DC power here includes, but is not limited to, output from new energy power generation devices. The grid-side line can be equivalently regarded as a resistor and an inductor connected in series, and its corresponding equivalent impedance can be obtained by monitoring the grid side. The converter includes an inverter module, which includes multiple switching transistors. The specific circuit structure used when multiple switching transistors are connected is not particularly limited. For example, it can be a three-phase full-bridge inverter structure.
[0022] The specifications of the converter mentioned in step S11 include, but are not limited to, the DC voltage received by the converter (which can be obtained by sampling circuit), the AC voltage and AC current output by the converter (which can be obtained by sampling circuit), the current switching frequency, and the internal electrical connection structure of the converter. The d-axis current component and q-axis current component here can be understood as: the output grid-side current in the dq-axis rotating coordinate system obtained by transforming the output grid-side current of the converter based on the three-phase stationary coordinate system to the two-phase synchronous dq-axis rotating coordinate system transformation strategy, which specifically includes the d-axis current component and the q-axis current component.
[0023] More specifically, in some embodiments, the changes in operating conditions include changes in specification parameters, and / or changes in equivalent impedance, and / or changes in the first set reference value corresponding to the d-axis current component, and / or changes in the second set reference value corresponding to the q-axis current component.
[0024] It is understandable that a change in operating condition is determined when the currently acquired specifications change compared to the previously acquired specifications (or when it is known that the currently acquired specifications are about to be adjusted to another specification); a change in operating condition is determined when the currently acquired equivalent impedance changes compared to the previously acquired equivalent impedance (or when it is known that the currently acquired equivalent impedance is about to change to another equivalent impedance); a change in operating condition is determined when the currently acquired first set reference value changes compared to the previously acquired first set reference value (or when it is known that the currently acquired first set reference value is about to be adjusted to another first set reference value); a change in operating condition is determined when the currently acquired second set reference value changes compared to the previously acquired second set reference value (or when it is known that the currently acquired second set reference value is about to be adjusted to another second set reference value); the change in operating condition here can be understood as a specific parameter change, for example, the first set reference value changes from 0A to 10A.
[0025] In addition, in some embodiments, the inherent control method includes an inherent control structure, an inherent control strategy, and the values of control parameters under the inherent control strategy; The target control method includes the optimized values of the control parameters.
[0026] Specifically, the inherent control method can be understood as the control method determined in the previous control cycle. The inherent control structure here can be a current loop control structure, a voltage loop control structure, or various dual-loop control structures, without any particular limitation. The inherent control strategy here can be various optimized control strategies, such as proportional-integral control strategy, proportional-integral-derivative control strategy, and the strategy of adding first-order filter poles to smooth measurement noise / interference, without any particular limitation. Correspondingly, the control parameters under the inherent control strategy here can be understood as follows: if the inherent control strategy is a proportional-integral control strategy, then the control parameters are proportional parameters minus integral parameters; if the inherent control strategy is a proportional-integral-derivative control strategy, then the control parameters are proportional parameters minus integral parameters minus derivative parameters.
[0027] The target control method may include optimized optimal values for control parameters. This means that the inherent control structure and inherent control strategy are not changed, but only the values of control parameters under the inherent control strategy are adjusted (i.e., the current inherent control structure and inherent control strategy can meet the application requirements). The switching transistors in the converter are controlled by the optimal values of the control parameters, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value. Furthermore, in some embodiments, the target control method also includes an optimized optimal control structure and / or an optimal control strategy. When the current inherent control structure and / or inherent control strategy cannot meet the requirement that the actual current output value follows the set reference value, the corresponding preset optimization model can also output the optimal control structure and / or optimal control strategy. For example, the original inherent control structure is a voltage loop plus feedforward control structure, and the optimal control structure is a voltage loop and current loop dual-loop control structure. The original inherent control strategy is a proportional-integral control strategy, and the optimal control structure is a proportional-integral control strategy combined with a lead-lag compensator. It can be understood that the optimal control parameters output by the preset optimization model at this time are the optimal values of the control parameters corresponding to the optimal control strategy.
[0028] It should also be noted that in some embodiments, the preset optimization model is LLM.
[0029] LLM (Large Language Model) possesses powerful code review and generation capabilities. It can be pre-trained to learn in conjunction with relevant control optimization theories so that it can output the corresponding target control method with good transient performance based on the input terms. Alternatively, an online LLM model can be used directly, which does not require pre-training. Before actually implementing the technical solution in this application, some simple information such as the research object and field is provided so that the LLM model can output effective code corresponding to the target control method more quickly and accurately.
[0030] In summary, this application provides a converter grid-connected control method, system, device, and storage medium. This scheme is based on a preset optimization model and input item settings, which facilitates real-time adjustment under changing converter operating conditions to determine the optimal target control mode, thereby achieving adaptive grid-connected control, avoiding control performance degradation and resonance instability, ensuring efficient and stable grid connection of new energy sources, and facilitating practical applications.
[0031] In some embodiments, the preset optimization model is deployed on a server terminal with edge computing capabilities.
[0032] Specifically, if the inherent control method is deployed on another terminal, then: More specifically, in some embodiments, the inherent control method, specification parameters, equivalent impedance, and operating condition changes are used as inputs to a preset optimization model to obtain the optimized target control method, including: Encapsulate the control code corresponding to the inherent control method into a DLL file; Upload the DLL file to the server terminal through the application programming interface of the preset optimization model, so as to input the DLL file into the preset optimization model; Input the specifications, equivalent impedance, and operating condition changes into the preset optimization model to obtain the optimized target control mode.
[0033] Specifically, the inherent control structure, inherent control strategy, and control parameter values under the inherent control strategy are uniformly encapsulated into a modular DLL file (Dynamic Link Library) for easy calling and uploading. The DLL file is uploaded to the server terminal through the application programming interface (API) of the preset optimization model to input the DLL file into the preset optimization model. Then, the specification parameters, equivalent impedance, and operating condition changes are input into the preset optimization model on the server terminal to obtain the optimized target control mode. It can be understood that the preset optimization model can also output the target control mode in the form of a DLL file.
[0034] The following is a statement explaining the validity of the technical solution provided in this application: Please refer to Figure 2 , Figure 2 This invention provides a transient performance comparison diagram, using the example of the d-axis current component about to jump from 0A to 10A under changing operating conditions. Figure 2 The blue lines represent the references (corresponding to the annotations in the legend); the orange lines represent the control effects when controlled in the manner described in the background art. Figure 2 The legend uses "Simulated (original)" as the label; the green line corresponds to the control effect when controlled in accordance with the method described in this application. Figure 2 The legend is marked with Simulated (tuned), and it can be clearly seen that the transient performance of the control scheme in this application is better.
[0035] Please refer to Figure 3 , Figure 3 This invention provides another transient performance comparison diagram, using the example of the d-axis current component about to jump from 0A to 20A under changing operating conditions. Figure 2The blue lines represent the references (corresponding to the annotations in the legend); the orange lines represent the control effects when controlled in the manner described in the background art. Figure 3 The legend uses "Simulated (original)" as the label; the green line corresponds to the control effect when controlled in accordance with the method described in this application. Figure 3 The legend is marked with Simulated (tuned), and it can be clearly seen that the transient performance of the control scheme in this application is better.
[0036] Please refer to Figure 4 , Figure 4 This invention provides a comparative schematic diagram of resonance suppression effects. The example used here illustrates a change in operating conditions where the d-axis current component is about to jump from 0A to 10A. Figure 4 The blue lines represent the references (corresponding to the annotations in the legend); the orange lines represent the control effects when controlled in the manner described in the background art. Figure 2 The legend uses "Simulated (original)" as the label; the green line corresponds to the control effect when controlled in accordance with the method described in this application. Figure 2 The legend is marked with Simulated (tuned), and it can be clearly seen that when controlled according to the scheme in this application, the resonance fluctuation is smaller, the vibration amplitude is smaller, and the transient performance is better.
[0037] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of a converter and grid control system provided by the present invention.
[0038] The converter and grid control system include: The first acquisition unit 21 is used to acquire the specifications of the converter and the equivalent impedance of the grid-side line; The second acquisition unit 22 is used to acquire the first set reference value corresponding to the d-axis current component and the second set reference value corresponding to the q-axis current component on the output grid side of the converter. The operating condition change determination unit 23 is used to determine the operating condition change when the operating condition of the converter changes. The optimization unit 24 is used to input the inherent control mode, specification parameters, equivalent impedance, and operating condition changes as input items into the preset optimization model to obtain the optimized target control mode. This allows the switching transistors in the converter to be turned on and off based on the target control mode, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value.
[0039] For a description of the converter-grid control system provided in this application, please refer to the embodiments of the converter-grid control method described above, and no special limitations are made here.
[0040] In some embodiments, the optimization unit 24 includes: The encapsulation unit is used to encapsulate the control code corresponding to the inherent control method into a DLL file; An upload unit is used to upload the DLL file to the server terminal through the application programming interface of a preset optimization model, so as to input the DLL file into the preset optimization model; The input unit is used to input the specification parameters, the equivalent impedance, and the operating condition changes into the preset optimization model to obtain the optimized target control mode.
[0041] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of a converter and grid control device provided by the present invention.
[0042] The converter and grid control device includes: Memory 31 is used to store computer programs; The processor 32 is used to implement the steps of the converter and grid control method as described above when executing the computer program.
[0043] For a description of the converter and grid control device provided in this application, please refer to the embodiments of the converter and grid control method described above, and no special limitations are made here.
[0044] The present invention also provides a computer storage medium storing a computer program, which, when executed by a processor, implements the steps of the converter-grid control method described above.
[0045] For a description of the computer storage medium provided in this application, please refer to the above-described embodiments of the converter and grid control method; no special limitations are made here.
[0046] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.
[0047] Furthermore, the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0048] Furthermore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A converter-grid control method, characterized in that, include: Obtain the specifications of the converter and the equivalent impedance of the grid-side lines; Obtain the first set reference value corresponding to the d-axis current component and the second set reference value corresponding to the q-axis current component on the output grid side of the converter; When it is determined that the operating condition of the converter has changed, the details of the change in operating condition are determined. The inherent control mode, the specified parameters, the equivalent impedance, and the operating condition changes are input into a preset optimization model to obtain an optimized target control mode. This optimized target control mode is then used to control the switching transistors in the converter to turn on and off, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value.
2. The converter grid connection control method as described in claim 1, characterized in that, The changes in operating conditions include changes in the specified parameters, and / or changes in the equivalent impedance, and / or changes in the first set reference value corresponding to the d-axis current component, and / or changes in the second set reference value corresponding to the q-axis current component.
3. The converter grid control method as described in claim 1, characterized in that, The preset optimization model is deployed on a server terminal with edge computing capabilities.
4. The converter grid control method as described in claim 3, characterized in that, The inherent control mode, the specified parameters, the equivalent impedance, and the operating condition changes are used as inputs to a preset optimization model to obtain the optimized target control mode, including: Encapsulate the control code corresponding to the inherent control method into a DLL file; The DLL file is uploaded to the server terminal through the application programming interface of the preset optimization model, so as to input the DLL file into the preset optimization model; The specified parameters, the equivalent impedance, and the operating condition changes are input into the preset optimization model to obtain the optimized target control mode.
5. The converter grid connection control method as described in claim 1, characterized in that, The inherent control method includes an inherent control structure, an inherent control strategy, and the values of control parameters under the inherent control strategy; The target control method includes the optimized values of the control parameters.
6. The converter grid connection control method as described in claim 5, characterized in that, The target control method also includes an optimized optimal control structure and / or an optimal control strategy.
7. The converter grid control method according to any one of claims 1 to 6, characterized in that, The preset optimization model is LLM.
8. A converter-grid control system, characterized in that, include: The first acquisition unit is used to acquire the specifications of the converter and the equivalent impedance of the grid-side lines; The second acquisition unit is used to acquire the first set reference value corresponding to the d-axis current component and the second set reference value corresponding to the q-axis current component on the output grid side of the converter. The operating condition change determination unit is used to determine the operating condition change when it is determined that the operating condition of the converter has changed. The optimization unit is used to input the inherent control mode, the specification parameters, the equivalent impedance, and the operating condition changes as input items into a preset optimization model to obtain an optimized target control mode. This optimized target control mode is then used to control the switching transistors in the converter to turn on and off, so that the actual value of the d-axis current component follows the first set reference value, and the actual value of the q-axis current component follows the second set reference value.
9. A converter-grid control device, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the converter-grid control method as described in any one of claims 1 to 7 when executing the computer program.
10. A computer storage medium, characterized in that, The computer storage medium stores a computer program, which, when executed by a processor, implements the steps of the converter-grid control method as described in any one of claims 1 to 7.