Hybrid mode multi-grid-connected inverter system optimization configuration method and system

Abstract

The application discloses a kind of mixed mode multi-grid-connected inverter system optimization configuration method and system, belong to power grid power quality control technical field.The multi-grid-connected inverter system includes multiple grid-connected inverters in parallel at point of common coupling, which is composed of network type control grid-connected inverter and follow network type control grid-connected inverter.The optimization configuration method includes the determination of two-layer optimization target, the determination of first-layer optimization target appointment condition, the establishment of first-layer optimization target function, the determination of second-layer optimization target constraint condition and the establishment of second-layer optimization target optimization target function.The configuration method uses tolerant hierarchical sequence method to divide multiple inverter system stability and economy and other multi-objective optimization problems into layers, which can reduce the power generation loss of multiple inverter system while effectively improving the grid stability under weak grid conditions.

Description

Technical Field

[0001] This invention belongs to the field of power grid power quality control technology, and relates to the control technology and system optimization configuration of new energy inverters. Specifically, it is a method and system for optimizing the configuration of a hybrid mode multi-grid-connected inverter system. Background Technology

[0002] As renewable energy sources such as photovoltaic and wind power generation account for an increasingly larger proportion of the power system, grid connection stability has become a crucial performance indicator for grid-connected inverter systems. On the one hand, grid conditions are becoming increasingly complex. Considering the time-varying, random, and power output fluctuations of renewable energy generation, the equivalent grid impedance often exhibits significant fluctuations. On the other hand, renewable energy generation systems typically integrate multiple centralized high-power grid-connected inverters. Long-distance transmission lines and transformers interconnect the system and connect it to the public grid. This results in individual inverters in multi-inverter systems exhibiting characteristics of high grid impedance in weak or extremely weak grids. Currently, the most widely used grid-connected control inverters face severe challenges to grid connection stability under conditions of significant grid impedance fluctuations and extremely weak grids.

[0003] Extensive research has been conducted both domestically and internationally on the stability issues of grid-connected inverters under conditions of large grid impedance fluctuations and extremely weak grids. Methods such as phase-locked loop (PLL) parameter optimization, output impedance reshaping, and hybrid grid-connected / grid-building control modes have been proposed. The first two methods still employ a single control mode for the grid-connected inverter, which has the drawback of only being able to operate stably within a relatively small range of grid impedance variations. The hybrid grid-connected / grid-building control mode method switches the multi-inverter system from a fully grid-connected control inverter to a hybrid mode, where the system simultaneously has both grid-connected and grid-building control inverters. This effectively improves the stability of multi-inverter systems under extremely weak grid conditions. Currently, numerous academic papers and patents have researched the optimization configuration of hybrid mode multi-grid-connected inverters, for example:

[0004] 1. Chinese patent document CN 108933447A, published on July 16, 2019, entitled "Dual-mode Control Method for Grid-connected Inverters Based on Short-Circuit Ratio under Weak Grid Conditions," addresses the common practice in multi-inverter systems operating in full current source mode under weak grid conditions of adjusting grid-connected inverter control parameters or grid-connected modes using grid impedance identification. The system's equivalent short-circuit ratio detection method accurately and intuitively reflects the state of the weak grid, providing a basis for the current source and voltage source grid-connected dual-mode switching of the grid-connected inverter. However, this paper does not consider the economic indicators when configuring new energy sources, and it does not address the optimal configuration capacity and optimal configuration location of the voltage source control mode inverter when the grid continues to weaken.

[0005] 2. The Chinese patent document CN 112653195A, published on April 13, 2021, entitled "A Robust Optimization Capacity Configuration Method for Grid-Connected Microgrids," establishes capacity configuration constraints based on distributed power source control parameters and cost. Considering both economic efficiency and robustness, it utilizes the CC&G algorithm for two-stage robust capacity configuration planning to achieve robust capacity allocation, thus ensuring the robustness of renewable energy power generation distribution. This provides a more convenient and easier-to-operate method for ensuring the reliability of planning schemes in actual production planning. However, this paper does not consider the optimal location configuration of renewable energy sources, especially since most renewable energy power generation systems connect to multiple centralized high-power grid-connected inverters via long-distance transmission lines to the public grid.

[0006] Based on the above literature, the existing technology has the following shortcomings:

[0007] 1. To improve the stability of multi-grid-connected inverter systems under extremely weak grid conditions, when switching from fully grid-connected control inverters to hybrid mode, the power generation efficiency loss of grid-connected control must be considered. The additional configuration of energy storage for grid-connected control mode will lead to increased costs. Therefore, it is necessary to study a multi-objective optimization configuration strategy that considers both economic efficiency and stability.

[0008] 2. Most new energy power generation systems are connected to multiple centralized high-power grid-connected inverters, which are connected to the public power grid through long-distance transmission lines. The near-end inverter and the far-end inverter of the public power grid have a large difference in equivalent grid impedance. However, the optimization configuration of existing hybrid mode multi-grid-connected inverters only considers capacity configuration and does not consider location configuration. Summary of the Invention

[0009] To overcome the limitations of the aforementioned solutions, this invention proposes an optimal configuration method for hybrid-mode multi-grid-connected inverter systems. This method employs a tolerant hierarchical sequence algorithm that simultaneously considers economic efficiency and stability to optimize the configuration of the hybrid-mode multi-grid-connected inverter system. Furthermore, it considers not only the optimal capacity configuration of the grid-connected control inverters but also their optimal location configuration. This method can obtain the optimal configuration scheme for hybrid-mode systems while achieving high economic efficiency and high stability, effectively improving the stability of multi-inverter systems under weak and extremely weak power grid conditions.

[0010] The objective of this invention is achieved as follows: This invention provides an optimized configuration method for a hybrid mode multi-grid-connected inverter system. The multi-grid-connected inverter system using this method includes a three-phase power grid and multiple grid-connected inverters connected in parallel at a common coupling point. These multiple grid-connected inverters consist of grid-type controlled grid-connected inverters and grid-following controlled grid-connected inverters.

[0011] The optimized configuration method includes the following steps:

[0012] S1, with optimal system economy as the first-level optimization objective f1(X), where X is the capacity configuration of the grid-connected inverter in the system, and optimal grid-connected stability as the second-level optimization objective f2(X, L), where L is the location configuration of the grid-connected inverter, and f2(X, L) takes precedence over f1(X).

[0013] S2, based on the given inverter power P set The power generation efficiency η of a single grid-connected inverter with grid-connected control is calculated.

[0014] S3, based on the given minimum power generation efficiency η of the multi-grid-connected inverter system min The initial constraints of the first-level optimization objective f1(X) are obtained by considering the power generation efficiency η of a single grid-connected inverter and the control efficiency of the grid-connected inverter.

[0015] S4. Based on the initial constraints of the first-level optimization objective f1(X), establish the optimization objective function of the first-level optimization objective f1(X) to obtain the optimal value X of the initial capacity configuration. 1 ;

[0016] S5, configure the initial capacity to the optimal value X 1 Increasing the tolerance ε1 yields the final constraints for the first-level optimization objective;

[0017] S6, gives the constraints for the location configuration L;

[0018] S7, combine the final constraints of the first-level optimization objective and the constraints of the position configuration L to form the constraints of the second-level optimization objective f2(X,L);

[0019] S8. Within the two-dimensional feasible region of the constraints of the second-level optimization objective f2(X,L), with the goal of maximizing the system's stability margin, establish the optimization objective function for the second-level optimization objective f2(X,L), and obtain the optimal capacity configuration value X based on this optimization objective function. * And the optimal value of location configuration L * .

[0020] Preferably, the power generation efficiency η of the single grid-connected inverter is calculated as follows:

[0021]

[0022] Where t is an intermediate variable in the integration, and P set Given the grid-connected inverter power, T is the power control delay of the grid-connected inverter.

[0023] Preferably, the initial constraint condition of the first layer optimization objective f1(X) is:

[0024]

[0025] Preferably, the objective function expression of the first-layer optimization objective f1(X) is:

[0026]

[0027] In the formula, T m1 The impedance ratio of the first layer. In the formula, Z g Z is the power grid impedance. GFL To control the output impedance of the grid-connected inverter, Z GFM , where is the output impedance of the grid-connected inverter, and PM is the phase margin used to obtain the expression.

[0028] Preferably, the final constraint condition of the first-level optimization objective is:

[0029] X 1 (1-ε1)<X<X 1 (1+ε1).

[0030] Preferably, the constraint condition for the position configuration L is:

[0031] Z line_min <L<Z line_max L>0

[0032] In the formula, Z line_min Z represents the minimum impedance of the transmission line in the power station. line_max This represents the maximum impedance of the transmission lines in the power station.

[0033] Preferably, the constraint condition for the second-layer optimization objective f2(X, L) is:

[0034]

[0035] Preferably, the expression for the objective function of the second-layer optimization objective f2(X, L) is:

[0036] max{PM(T m2 )}

[0037] In the formula, PM represents the phase margin used to obtain the expression, and T... m2 This is the expression for the second-layer impedance ratio. Z g Z is the power grid impedance. GFL To control the output impedance of the grid-connected inverter, Z GFM S represents the output impedance of the grid-connected inverter with grid-connected control, and S is the Laplace operator.

[0038] This invention also provides a hybrid mode multi-grid-connected inverter system optimization configuration system, comprising:

[0039] The control module is used to establish the first-level optimization objective f1(X) and the second-level optimization objective f2(X, L);

[0040] Used to determine the given inverter power P set A calculation module for the power generation efficiency η of a single grid-connected inverter with grid-connected control;

[0041] The control module is used to determine the initial constraints of the first-level optimization objective f1(X);

[0042] The optimization objective function f1(X) is used to establish the first-level optimization objective, and the optimal value X of the initial capacity configuration is obtained. 1 The control module;

[0043] The control module is used to determine the constraints of the second-level optimization objective f2(X,L);

[0044] The optimization objective function f2(X, L) is used to establish the second-level optimization objective and to obtain the optimal capacity configuration value X. * And the optimal value of location configuration L * The control module;

[0045] The module and microprocessor are programmed or configured to perform the steps of the hybrid-mode multi-grid-connected inverter system optimization configuration method, and a microprocessor and memory are also included.

[0046] The present invention also provides a computer-readable storage medium storing a computer program programmed or configured to perform the hybrid-mode multi-grid-connected inverter system optimization configuration method.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] 1. This invention provides an optimized configuration method for a hybrid mode multi-grid-connected inverter system. Through a tolerant hierarchical sequence algorithm, it proposes a multi-objective optimized configuration strategy that considers both economic efficiency and stability, avoiding the increased cost caused by additional energy storage configuration while simultaneously achieving the highest power generation efficiency.

[0049] 2. When multiple grid-connected inverters are operating in parallel, there is a significant difference in equivalent grid impedance between the near-end inverter and the far-end inverter of the public grid. This optimization method not only considers the optimal capacity configuration of the grid-connected control inverter, but also obtains the optimal location configuration, which can effectively improve the stability of the multi-inverter system under extremely weak grid conditions. Attached Figure Description

[0050] Figure 1This is a topology diagram of the main circuit of a high-proportion new energy power generation system applying the optimized configuration method of the present invention in an embodiment of the present invention.

[0051] Figure 2 This is a flowchart of the optimized configuration method of the present invention.

[0052] Figure 3 A schematic diagram illustrating the optimal capacity configuration under different power grid conditions.

[0053] Figure 4 A schematic diagram illustrating the optimal location configuration under different power grid conditions.

[0054] Figure 5 Analysis of PCC voltage waveform and THD for fully grid-controlled inverters under weak grid conditions.

[0055] Figure 6 Analysis of PCC voltage waveform and THD for hybrid mode multi-grid-connected inverters under weak grid conditions. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0057] This invention provides an optimized configuration method for a hybrid mode multi-grid-connected inverter system. The multi-grid-connected inverter system using this method is a high-proportion renewable energy power generation system, including a three-phase power grid and multiple grid-connected inverters connected in parallel at a common coupling point. These multiple grid-connected inverters consist of grid-connected inverters with grid-forming control and grid-following control.

[0058] In an embodiment of the present invention, the main circuit topology of the high-proportion new energy power generation system of the present invention is shown below. Figure 1 .Depend on Figure 1 As can be seen, the high proportion of new energy power generation includes multiple grid-connected inverters with identical topologies, a three-phase grid impedance, and a three-phase grid. The grid-connected inverter includes a three-phase DC power supply, a three-phase full-bridge inverter circuit, and a three-phase LC filter connected in sequence. The outputs of multiple three-phase LC filters are connected in parallel to a common coupling point PCC, and then connected in series with the three-phase grid impedance and the three-phase grid in sequence.

[0059] exist Figure 1 In the diagram, 10 represents the DC power supply, 20 represents the three-phase full-bridge inverter circuit, 30 represents the three-phase LC filter, 40 represents the three-phase grid impedance, and 50 represents the three-phase grid. Udc represents the DC voltage, C represents the filter capacitor of the three-phase LC filter, L1 represents the filter inductance of the three-phase LC filter, and Rd represents the filter resistor of the three-phase LC filter.

[0060] The present invention provides a method for optimizing the configuration of a hybrid multi-grid-connected inverter system. The optimization configuration method uses a tolerant hierarchical sequence method to hierarchically divide the multi-objective optimization problem of capacity optimization and location optimization of the multi-inverter system. Figure 2 This is a flowchart illustrating the optimized configuration method for a hybrid-mode multi-grid-connected inverter system according to the present invention. Figure 2 As can be seen, the optimized configuration method includes the following steps:

[0061] Step 1: The first-level optimization objective is f1(X) with optimal system economy, where X is the capacity configuration of the grid-connected inverter in the system. The second-level optimization objective is f2(X, L) with optimal grid-connected stability, where L is the location configuration of the grid-connected inverter. f2(X, L) takes precedence over f1(X).

[0062] Step 2, based on the given inverter power P set The power generation efficiency η of a single grid-connected inverter was calculated.

[0063] In this embodiment of the invention, the power generation efficiency η of the single grid-connected inverter is calculated as follows:

[0064]

[0065] Where t is an intermediate variable in the integration, and P set Given the grid-connected inverter power, T is the power control delay of the grid-connected inverter.

[0066] In this embodiment, no energy storage inverter is configured. That is, the grid-connected inverter needs to reserve a certain amount of power generation capacity to support voltage and frequency, so there will be a certain loss of power generation efficiency.

[0067] Step 3, based on the given minimum power generation efficiency η of the multi-grid-connected inverter system min The initial constraints of the first-level optimization objective f1(X) are obtained by considering the power generation efficiency η of a single grid-connected inverter and the grid-connected inverter.

[0068] In this embodiment of the invention, the initial constraint condition of the first layer optimization objective f1(X) is:

[0069]

[0070] Step 4: Based on the initial constraints of the first-level optimization objective f1(X), establish the optimization objective function of the first-level optimization objective f1(X) to obtain the optimal value X of the initial capacity configuration. 1 .

[0071] In this embodiment of the invention, the objective function expression of the first-layer optimization objective f1(X) is:

[0072]

[0073] In the formula, T m1 The impedance ratio of the first layer. In the formula, Z g Z is the power grid impedance. GFL To control the output impedance of the grid-connected inverter, Z GFM , where is the output impedance of the grid-connected inverter, and PM is the phase margin used to obtain the expression.

[0074] Because grid-connected control strategies incur certain power generation efficiency losses, to achieve optimal system economy, it is necessary to configure grid-connected control inverters with the smallest possible capacity while ensuring grid stability. Therefore, the grid impedance Z should be set accordingly. g Subsequently, the short-circuit ratio (SCR) is used to more intuitively describe the power grid state. In the formula, Un is the rated voltage of the grid-connected inverter, In is the rated current of the grid-connected inverter, and f0 is the fundamental frequency. The numerical relationship between the short-circuit ratio (SCR) and the capacity configuration X is obtained using the D-segmentation method as follows: Figure 3 As shown, based on the optimization objective function expression of the first-layer optimization objective f1(X), the minimum capacity configuration required to maintain the phase margin of the first-layer impedance ratio expression Tm1 at 30° is selected, i.e. Figure 3 The optimal capacity configuration point shown above is (2, 0.55).

[0075] Step 5: Configure the initial capacity to the optimal value X. 1 Increasing the tolerance ε1 yields the final constraints for the first-level optimization objective.

[0076] In this embodiment of the invention, the final constraint condition of the first-layer optimization objective is:

[0077] X 1 (1-ε1)<X<X 1 (1+ε1).

[0078] Step 6: Give the constraints for the location configuration L.

[0079] In this embodiment of the invention, the constraint condition for the position configuration L is:

[0080] Z line_min <L<Z line_max L>0

[0081] In the formula, Z line_min Z represents the minimum impedance of the transmission line in the power station. line_max This represents the maximum impedance of the transmission lines in the power station.

[0082] Step 7: Combine the final constraints of the first-level optimization objective and the constraints of the position configuration L to form the constraints of the second-level optimization objective f2(X, L).

[0083] In this embodiment of the invention, the constraint condition for the second-layer optimization objective f2(X, L) is:

[0084]

[0085] Step 8: Within the two-dimensional feasible region of the constraints of the second-level optimization objective f2(X,L), with the goal of maximizing the system's stability margin, establish the optimization objective function for the second-level optimization objective f2(X,L), and obtain the optimal capacity configuration value X based on this optimization objective function. * And the optimal value of location configuration L * .

[0086] In this embodiment of the invention, the expression for the optimization objective function of the second-layer optimization objective f2(X, L) is:

[0087] max{PM(T m2 )}

[0088] In the formula, PM represents the phase margin used to obtain the expression, and T... m2 This is the expression for the second-layer impedance ratio. Z g Z is the power grid impedance. GFL To control the output impedance of the grid-connected inverter, Z GFM S represents the output impedance of the grid-connected inverter with grid-connected control, and S is the Laplace operator.

[0089] Because the near-end and far-end inverters of the public power grid have significant differences in equivalent grid impedance, and because the output line impedance has a significant impact on the stability of the grid-connected inverter, in order to achieve the goal of optimal system stability, it is necessary to configure the grid-connected control inverters with the minimum possible capacity while selecting the optimal location for L... * Therefore, the grid impedance Z is set. g Subsequently, the short-circuit ratio (SCR) is used to more intuitively describe the power grid state. In the formula, Un is the rated voltage of the grid-connected inverter, In is the rated current of the grid-connected inverter, and f0 is the fundamental frequency. The numerical relationship between the short-circuit ratio (SCR) and the location configuration L is obtained using the D-segmentation method as follows: Figure 4 As shown, based on the optimization objective function expression of the second-layer optimization objective f2(X, L), we take the expression T that allows the second-layer impedance ratio to be optimized. m2 The phase margin is maximized, and the required position configuration is optimal, i.e. Figure 4 The optimal location configuration point shown above is (0.027, 0.5).

[0090] To demonstrate the beneficial effects of the present invention, a simulation was performed.

[0091] Figure 5 This paper analyzes the PCC voltage waveform and THD of a grid-connected inverter under full grid-following control in a weak grid environment. Under this condition, the grid short-circuit ratio (SCR) is 2, the PCC voltage waveform is significantly distorted, and the system's grid-connected voltage THD is 1105.12%.

[0092] After applying the hybrid mode multi-grid-connected inverter system optimization configuration method provided by this invention, Figure 6 The PCC voltage waveform and THD of the hybrid mode multi-grid-connected inverter under weak grid conditions are analyzed. Under this condition, the grid short-circuit ratio (SCR) is 2, the PCC voltage resonance is significantly suppressed, and the grid-connected voltage THD of the system is 2.24%.

[0093] This invention also provides a hybrid mode multi-grid-connected inverter system optimization configuration system, comprising:

[0094] The control module is used to establish the first-level optimization objective f1(X) and the second-level optimization objective f2(X, L);

[0095] Used to determine the given inverter power P set A calculation module for the power generation efficiency η of a single grid-connected inverter with grid-connected control;

[0096] The control module is used to determine the initial constraints of the first-level optimization objective f1(X);

[0097] The optimization objective function f1(X) is used to establish the first-level optimization objective, and the optimal value X of the initial capacity configuration is obtained. 1 The control module;

[0098] The control module is used to determine the constraints of the second-level optimization objective f2(X,L);

[0099] The control module is used to establish the optimization objective function f2(X, L) of the second-level optimization objective and to obtain the optimal value X* for capacity configuration and the optimal value L* for location configuration.

[0100] The module and microprocessor are programmed or configured to perform the steps of the hybrid-mode multi-grid-connected inverter system optimization configuration method, and a microprocessor and memory are also included.

[0101] The present invention also provides a computer-readable storage medium storing a computer program programmed or configured to perform the hybrid-mode multi-grid-connected inverter system optimization configuration method.

[0102] The circuit topology, control strategy, and method of the present invention described above can be viewed as a hardware embodiment of the circuit topology alone, or as a software embodiment containing only the control strategy and method, or as a combined hardware and software implementation based on the control strategy and method of the circuit topology and modules. Furthermore, the control strategy and method of the present invention can be implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code, appearing in the form of a computer program product; and can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0103] Furthermore, the embodiments of the present invention are described in conjunction with flowcharts and / or block diagrams, and should be understood to mean that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, generate instructions for implementing the flowcharts of the present invention. Figure 1 One or more processes and / or boxes Figure 1 The means specifying the functions in one or more boxes. These computer program instructions may also be stored in a computer-readable storage medium capable of directing a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means implemented in the process of the invention. Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process of the present invention. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0104] Therefore, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any changes and modifications made by those skilled in the art based on the specific embodiments of the present invention and the above circumstances should be considered as equivalent solutions of this application and should fall within the protection scope of the present invention.

Claims

1. A method for optimizing the configuration of a hybrid mode multi-grid-connected inverter system, wherein the multi-grid-connected inverter system using this method includes a three-phase grid and multiple grid-connected inverters connected in parallel at a common coupling point, wherein the multiple grid-connected inverters consist of grid-connected inverters with grid-connected control and grid-following control; Its features are, The optimized configuration method includes the following steps: S1, with optimal system economy as the first-level optimization objective f1(X), where X is the capacity configuration of the grid-connected inverter in the system, and optimal grid-connected stability as the second-level optimization objective f2(X,L), where L is the location configuration L of the grid-connected inverter, and f2(X,L) takes precedence over f1(X). S2, based on the given inverter power The power generation efficiency of a single grid-connected inverter was calculated. ; S3, based on the given minimum power generation efficiency of the multi-grid-connected inverter system Power generation efficiency of a single grid-connected inverter Thus, the initial constraints of the first-level optimization objective f1(X) are obtained; S4. Based on the initial constraints of the first-level optimization objective f1(X), establish the optimization objective function of the first-level optimization objective f1(X) to obtain the optimal value X of the initial capacity configuration. 1 ; S5, configure the initial capacity to the optimal value X 1 Increase tolerance Then the final constraints of the first-level optimization objective are obtained; S6, gives the constraints on the location configuration L; S7, combine the final constraints of the first-level optimization objective and the constraints of the position configuration L to form the constraints of the second-level optimization objective f2(X,L); S8. Within the two-dimensional feasible region of the constraints of the second-level optimization objective f2(X,L), with the goal of maximizing the system's stability margin, establish the optimization objective function for the second-level optimization objective f2(X,L), and obtain the optimal capacity configuration value based on this optimization objective function. and optimal value for location configuration ; The power generation efficiency of the single grid-connected inverter The calculation formula is as follows: Where t is an intermediate variable in the integration. For a given grid-connected inverter power, For power control delay of grid-connected inverters; The objective function expression for the first-level optimization objective f1(X) is: In the formula, T m1 The impedance ratio of the first layer. In the formula, For grid impedance, To control the output impedance of the grid-connected inverter, The output impedance of the grid-connected inverter is defined as the control output impedance, and PM is the phase margin used to obtain the expression. The objective function of the second-level optimization objective f2(X,L) is expressed as follows: In the formula, PM represents the phase margin used to obtain the expression, and T... m2 This is the expression for the second-layer impedance ratio. , For grid impedance, To control the output impedance of the grid-connected inverter, S represents the output impedance of the grid-connected inverter with grid-connected control, and S is the Laplace operator.

2. The method for optimizing the configuration of a hybrid mode multi-grid-connected inverter system according to claim 1, characterized in that, The initial constraints of the first-level optimization objective f1(X) are as follows: 。 3. The method for optimizing the configuration of a hybrid mode multi-grid-connected inverter system according to claim 1, characterized in that, The final constraint condition for the first-level optimization objective is: 。 4. The method for optimizing the configuration of a hybrid mode multi-grid-connected inverter system according to claim 1, characterized in that, The constraints on the location configuration L are as follows: In the formula, This represents the minimum impedance of the transmission lines in the power station. This represents the maximum impedance of the transmission lines in the power station.

5. The method for optimizing the configuration of a hybrid mode multi-grid-connected inverter system according to claim 1, characterized in that, The constraints for the second-level optimization objective f2(X,L) are: 。 6. A hybrid mode multi-grid-connected inverter system optimization configuration system, characterized in that, include: The control module is used to establish the first-level optimization objective f1(X) and the second-level optimization objective f2(X,L); Used to determine the given inverter power The power generation efficiency of a single grid-connected inverter was calculated. The calculation module; The control module is used to determine the initial constraints of the first-level optimization objective f1(X); The optimization objective function f1(X) is used to establish the first-level optimization objective, and the optimal value X of the initial capacity configuration is obtained. 1 The control module; The control module is used to determine the constraints of the second-level optimization objective f2(X,L); The objective function for establishing the second-level optimization objective f2(X,L) is used to obtain the optimal capacity configuration value. and optimal value for location configuration The control module; The module and microprocessor are programmed or configured to perform the steps of the hybrid mode multi-grid-connected inverter system optimization configuration method according to any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that is programmed or configured to perform the hybrid mode multi-grid-connected inverter system optimization configuration method according to any one of claims 1 to 5.

Images