Hybrid grid control method, device, system, storage medium and electronic equipment

Abstract

The application provides a hybrid power grid control method, device, system, storage medium and electronic equipment, and belongs to the technical field of power grid control. The hybrid power grid control method comprises the following steps: acquiring a frequency reference value of an alternating current subsystem and a voltage reference value of a direct current subsystem; acquiring a direct current voltage of the direct current subsystem in real time; and based on the frequency reference value of the alternating current subsystem, the voltage reference value and the direct current voltage of the direct current subsystem, a preset controller model is used to control the interconnected converter, so as to control the frequency of the alternating current subsystem. The accuracy of power sharing is improved, and a fast response to alternating current interference is provided through the inertia of the capacitor, so that the frequency of the alternating current system and the average direct current bus voltage of each direct current system converge to the reference value, and the optimal power distribution can be realized in the steady state of the system.

Description

Technical Field

[0001] This invention relates to the field of power grid control technology, and more specifically to a hybrid power grid control method, a hybrid power grid control device, a hybrid power grid control system, a machine-readable storage medium, and an electronic device. Background Technology

[0002] Given the increasing number of solar or wind power converters used in large-scale renewable energy plants in oil fields, hybrid AC / DC networks have become a key technology for sustainable power systems. Hybrid AC / DC networks can easily integrate such renewable energy sources and combine the advantages of both DC and AC grids into a single grid, achieving high-efficiency operation. DC grids offer several advantages over traditional AC systems: lower power losses, primarily due to the absence of reactive power, higher power transmission capacity, and the ability to facilitate the connection of asynchronous AC grids. However, AC technology is already mature and more suitable for certain applications. Therefore, combining AC / DC networks through interconnected voltage source converters to form hybrid AC / DC networks is advantageous.

[0003] Hybrid AC / DC networks present new challenges in frequency and voltage control. In particular, an unresolved issue is the control of interconnecting converters, aiming to ensure stability while maintaining proper frequency and voltage regulation. This is challenging because interconnecting converter operation affects both AC frequency and DC voltage. Furthermore, in many cases, a prescribed allocation is required to achieve economic optimization among generator sets.

[0004] Currently, there are many controllers available for AC or DC networks or individual microgrids, ranging from simple droop-based strategies to sliding mode control for medium-voltage DC networks, distributed consensus control for medium-voltage DC networks, and model predictive control. For hybrid AC / DC microgrids, achieving optimal power allocation between AC and DC power sources is more challenging because control actions on both the AC and DC sides affect the entire network. Summary of the Invention

[0005] The purpose of this invention is to provide a hybrid power grid control method, a hybrid power grid control device, a hybrid power grid control system, a machine-readable storage medium, and an electronic device. The hybrid power grid control method ensures that the AC system frequency and the average DC bus voltage of each DC system converge to the reference value, and the system can achieve optimal power distribution even in steady state.

[0006] To achieve the above objectives, a first aspect of this application provides a hybrid power grid control method for an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnecting converter; the method includes: Obtain the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; The DC voltage of the DC subsystem is acquired in real time. Based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, a preset controller model is used to control the interconnect converter in order to control the frequency of the AC subsystem.

[0007] In this embodiment, controlling the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage to control the frequency of the AC subsystem includes: Based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem, the proportionality coefficient is calculated. Substituting the proportional coefficient and the DC voltage of the DC subsystem into the preset controller model, the AC frequency of the AC subsystem is obtained. Based on the AC frequency of the AC subsystem, the AC output terminal of the interconnect converter is controlled to control the frequency of the AC subsystem.

[0008] In this embodiment of the application, the preset controller model is: , in , The AC bus connected to the interconnect converter is used The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: The set of DC buses connected to the interconnect converter is represented as follows: , For AC bus, It is a DC bus. This is the proportionality coefficient. The DC voltage of the DC bus in the DC subsystem is given. The frequency of the AC bus in the AC subsystem is given.

[0009] In this embodiment of the application, the preset controller model is a distributed controller, and the distributed controller is: , Among them, The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: , For AC bus, This is the proportionality coefficient. This is the average voltage of all nodes in the DC subsystem. The frequency of the AC bus in the AC subsystem is given.

[0010] In this embodiment of the application, the method further includes: The interconnect converter is controlled using a pre-set distributed averaging algorithm model.

[0011] In this embodiment of the application, the preset distributed averaging algorithm model is: , , in, The positive time constant in the diagonal matrix. A column vector of synchronization variables. The derivative of the synchronous communication variable. Let K be the inverse matrix of cost coefficients, and K be the diagonal matrix of positive coefficients. For the imaginary frequency difference of the hybrid power grid, For the Laplace operator, This is the generator power vector.

[0012] In this embodiment of the application, it also includes: The current frequency of the AC subsystem is obtained in real time; Based on the frequency reference value of the DC subsystem, the voltage reference value of the AC subsystem, and the current frequency, a preset controller model is used to control the interconnect converter in order to control the DC voltage of the DC subsystem.

[0013] A second aspect of this application provides a hybrid power grid control device for an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnect converter; the device includes: The first acquisition module is used to acquire the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; The second acquisition module is used to acquire the DC voltage of the DC subsystem in real time. The control module is used to control the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, so as to control the frequency of the AC subsystem.

[0014] In this embodiment of the application, the control module includes: The first calculation unit is used to calculate the proportionality coefficient based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem. The second calculation unit is used to substitute the proportional coefficient and the DC voltage of the DC subsystem into a preset controller model to obtain the AC frequency of the AC subsystem. The control unit is used to control the AC output terminal of the interconnect converter based on the AC frequency of the AC subsystem, so as to control the frequency of the AC subsystem.

[0015] A third aspect of this application discloses a hybrid power grid control system, comprising a controller, an AC subsystem, and a DC subsystem, wherein the AC subsystem and the DC subsystem are connected via an interconnect converter, and the controller controls the interconnect converter using the aforementioned hybrid power grid control method.

[0016] A fourth aspect of this application provides an electronic device, the electronic device comprising: At least one processor; A memory connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, which implements the hybrid power grid control method described above by executing the instructions stored in the memory.

[0017] A fifth aspect of this application provides a machine-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform the hybrid power grid control method described above.

[0018] The above technical solution involves acquiring the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; acquiring the DC voltage of the DC subsystem in real time; and using a preset controller model to control the interconnect converter based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, thereby controlling the frequency of the AC subsystem. By proportionally correlating the AC frequency with the DC voltage, changes in the DC-side capacitor voltage directly affect the AC-side frequency, allowing the DC capacitor energy to participate in the dynamic adjustment of the system. This control method does not directly control power transmission but involves the frequency and voltage of both the AC and DC sides separately. This not only improves the accuracy of power sharing but also provides a rapid response to AC interference through capacitive inertia, ensuring that the AC system frequency and the average DC bus voltage of each DC system converge to the reference value, enabling the system to achieve optimal power distribution even in steady state.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 The illustration shows a schematic flowchart of a hybrid power grid control method according to an embodiment of this application; Figure 2 An interconnect converter connection diagram according to an embodiment of this application is schematically shown; Figure 3 An AC / DC network (hybrid topology) diagram according to an embodiment of this application is illustrated schematically; Figure 4 An AC / DC network (ring topology) diagram according to an embodiment of this application is schematically shown; Figure 5 The schematic diagram illustrates a structural schematic of a hybrid power grid control device according to an embodiment of this application; Figure 6 The diagram illustrates the internal structure of a computer device according to an embodiment of this application.

[0021] Explanation of reference numerals in the attached figures 410 - First acquisition module; 420 - Second acquisition module; 430 - Control module; A01 - Processor; A02 - Network interface; A03 - Internal memory; A04 - Display screen; A05 - Input device; A06 - Non-volatile storage medium; B01 - Operating system; B02 - Computer program. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0023] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with the relevant provisions of national laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0024] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0026] Please refer to Figure 1 , Figure 1 The schematic diagram illustrates a flow chart of a hybrid power grid control method according to an embodiment of this application. This embodiment provides a hybrid power grid control method for an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnect converter; the method includes the following steps: Step 210: Obtain the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; In this embodiment, please refer to Figures 2-4 , Figure 2 An interconnect converter connection diagram according to an embodiment of this application is schematically shown; Figure 3 An AC / DC network (hybrid topology) diagram according to an embodiment of this application is illustrated schematically; Figure 4 A schematic diagram of an AC / DC network (ring topology) according to an embodiment of this application is shown. An interconnecting converter is located between the AC subsystem and the DC subsystem. The AC / DC hybrid network may include one AC subsystem, one DC subsystem, and one or more interconnecting converters, or multiple interconnecting converters. In the case of multiple interconnecting converters, the AC / DC hybrid network adopts a hybrid topology. Both the frequency reference value and the voltage reference value can be input by the user.

[0027] Step 220: Acquire the DC voltage of the DC subsystem in real time; Step 230: Based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, a preset controller model is used to control the interconnect converter to control the frequency of the AC subsystem.

[0028] In this embodiment, a general AC / DC hybrid network is considered, whose bus set is represented as follows: The collection of transmission lines consists of The network consists of multiple AC and DC subsystems. We use... Denotes the set of subsystems, and has ,in and This represents a set of buses, each belonging to an AC subsystem. and DC subsystem Assuming each subsystem is already connected, and only connected to the rest of the network via interconnect converters, such as... Figure 2 As shown. Each AC subsystem i is represented by a connected graph in any direction. To describe each DC subsystem j using a connectivity graph in any direction. To describe. For each bus We use i: i→j and k: j→k to represent the predecessor and successor of bus j, respectively. For convenience, we define all AC buses. and all DC buses The set of such that Similarly, we define the set of all communication edges. and the set of all DC edges The connection between the AC and DC buses is achieved by interconnecting converters, whose set is represented as follows: . The AC bus connected to the interconnect converter is used , The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows. Similarly, the set of DC buses connected to the interconnect converter is represented as... .

[0029] The dynamic equations of the hybrid AC / DC network are as follows: (1) in It is the angle difference vector. Let be the frequency of the i-th system. Let be the frequency of the j-th system.

[0030] (2) in For generator inertia, For the generator to output active power, For load power, Let i be the power transmitted from system i to system j. Let J be the power transmitted from system j to system k. is the system damping coefficient.

[0031] (3) (4) in This refers to the capacitor in a DC system.

[0032] (5) in and Let be the susceptance and conductance of line ij.

[0033] Now we write the system dynamics in matrix form, with angle difference vectors. The vector representation of the AC frequency deviation from the nominal value (50 or 60 Hz) is as follows: The vector representation of the DC voltage deviation from the nominal value is as follows: M is the generator inertia. diagonal matrix, Damping coefficient The frequency corresponding to the AC bus is used. This indicates that the frequency vector of the converter bus is... The diagonal matrix of the DC bus capacitors is as follows: Generator power vector is used The load power vector is represented by... This is indicated. For buses without converters, we also use the symbol [symbol missing]. ,Right now and use This represents the vector that powers the converter. Similarly, on the converter bus... Here, we use the mark The power transfer vector is defined as follows: Each of them Matrix A is a graph The correlation matrix. The system equation is expressed as: (6) (7) Equilibrium conditions: (2) The equilibrium of the system is defined by the following conditions: (8) (9) Assume that (2) has an equilibrium point, and use This indicates the equilibrium point. Individual equilibrium values ​​are also indicated by an asterisk, for example... .

[0034] The optimal power sharing among all power sources should be expressed more formally by considering the minimization of a quadratic function: (10) in This is the cost function.

[0035] (11) (12) Where Q is a positive definite diagonal matrix containing the cost coefficients of each energy source, 1 is a vector of 1s with appropriate dimensions, and 0 is a vector of 0s with appropriate dimensions. Constraint (11) is the requirement for balanced power, i.e., total power generation equals demand, while (12) indicates that the power generation of the converter's AC bus is zero. To go further, we define a diagonal matrix. Make , and , Using the standard method of Lagrange multipliers, vectors are defined. Then the solution to the optimization problem for: (13) Master-slave control: Assuming an communication system Control and DC systems Control is represented as: (14) in This is the inverse cost matrix of the pressure drop coefficient. It is a constant. ω and V are column vectors of AC frequency and DC voltage deviation, respectively. Power generation It is a constant reference that satisfies the droop control scheme of (4) total load. Limiting frequency and voltage deviation can be achieved through... An appropriate large droop coefficient is selected to satisfy the requirement. This invention uses a proportional droop control scheme; each AC generator receives input from... To output Each DC generator receives input To output Around their respective equilibrium values and conduct.

[0036] Let the voltage angle at the AC output of the interconnect converter be... for: (15) That is, the frequency is determined by: (16) in , This will proportionally adjust the AC frequency deviation to the DC voltage deviation using a selected constant. Therefore, (15) it is required that the frequency on the AC side of the interconnect converter be set directly by the interconnect converter, rather than controlling the power transfer through the interconnect converter as in traditional interconnect converter control schemes. The relationship between AC frequency and DC voltage allows for appropriate stability and optimal characteristics to be provided for the network.

[0037] Assuming the converter is lossless and the internal dynamics are fast enough compared to the network dynamics. (Settings) ,in and These are reference values ​​for AC grid frequency and DC grid voltage, and are relatively large. The value results in a smaller DC voltage deviation and a larger AC frequency deviation. (15) Instead of directly controlling power transmission, the frequency and voltage on the AC and DC sides are handled separately. This not only improves the accuracy of power sharing, but also provides a fast response to AC interference through capacitive inertia and uses the inertia of the AC system to regulate the DC voltage when appropriate.

[0038] In some embodiments, controlling the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage to control the frequency of the AC subsystem includes: First, the proportional coefficient is calculated based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; In this embodiment, the aforementioned proportionality coefficient refers to the ratio of the frequency reference value of the AC subsystem to the voltage reference value of the DC subsystem.

[0039] Then, the proportional coefficient and the DC voltage of the DC subsystem are substituted into the preset controller model to obtain the AC frequency of the AC subsystem. The preset controller model is as follows: , in , The AC bus connected to the interconnect converter is used The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: The set of DC buses connected to the interconnect converter is represented as follows: , For AC bus, It is a DC bus. This is the proportionality coefficient. The DC voltage of the DC bus in the DC subsystem is given. The frequency of the AC bus in the AC subsystem is given.

[0040] Finally, based on the AC frequency of the AC subsystem, the AC output terminal of the interconnect converter is controlled to control the frequency of the AC subsystem.

[0041] In this embodiment, once the AC frequency of the AC subsystem is obtained, the AC output of the interconnect converter can be controlled to ensure that the frequency of the AC subsystem is the AC frequency of the AC subsystem. The above steps proportionally correlate the AC frequency with the DC voltage, allowing changes in the DC-side capacitor voltage to directly affect the AC-side frequency, thus enabling the DC capacitor energy to participate in the system's dynamic regulation. For example, when the DC voltage changes due to system disturbances, the AC frequency will change accordingly based on this relationship, thereby initiating the system's dynamic regulation process.

[0042] Consider a dynamical system described by (1) and (2), with control schemes in (6) and (16), and an equilibrium point. Then, there exists an open neighborhood of this equilibrium point such that all solutions of (1), (2), (6), and (16) originating from this neighborhood converge to the set of equilibrium points defined in (3). The local convergence of solutions of (1), (2), (6), and (16) with respect to the set of equilibrium points is shown. Due to the sinusoidal power transfer in (5), the result is local; if these were linearized, it would become global.

[0043] When the DC line resistance becomes arbitrarily small, the power sharing of systems (1) and (2) with control schemes (6) and (16) becomes arbitrarily close to the solution of optimization problem (4). That is, when the line resistance becomes arbitrarily small, the equilibrium point of the considered system tends to the global minimum of (4).

[0044] It should be noted that in real-world networks, there will always be some small DC line resistances that affect power sharing. In a linear droop-controlled DC grid, there is a fundamental trade-off between voltage regulation and power sharing accuracy, which can be adjusted by changing the droop gain. However, if these line resistances are very small, the voltage deviation will also be small, and power sharing will be close to optimal.

[0045] Consider the dual droop scheme commonly used in the master control of interconnect converters: (17) in, and The droop coefficients directly control power transfer (in practice, the interconnect converter controls power transfer by changing its output voltage angle until equation (17) is satisfied). Clearly, (17) cannot guarantee correct power sharing for disturbances on any bus under the same assumptions. A system-wide synchronization variable is needed for the droop control source to contribute power proportionally to its droop coefficient. The proposed controller (16) achieves this by associating the AC frequency with the DC voltage. In contrast, the dual-droop controller (17) does not provide this relationship.

[0046] It should be noted that the AC frequency and DC voltage should not deviate too much from the reference values, that is, for all busbars. For all busbars .in, Let j be the frequency of the j-th system. Let the frequency tolerance of the j-th system be... Let be the voltage of the j-th system. Let be the allowable voltage deviation of the j-th system.

[0047] In some embodiments, it can also be distributed control, using communication to achieve precise power sharing, frequency and voltage regulation. That is, the preset controller model is a distributed controller, which is: , Among them, The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: , For AC bus, This is the proportionality coefficient. This is the average voltage of all nodes in the DC subsystem. The frequency of the AC bus in the AC subsystem is given.

[0048] In this embodiment, the average DC voltage deviation k of each subsystem is assumed to be the capacitor-weighted average. If it means: (18) The DC voltage within each subsystem is either communicated within the network to obtain... (For small subsystems), either obtain them through an appropriate fast distributed method. This is so that its dynamics can be decoupled from the stability analysis in this paper. According to (18), then: (19) DC branch current Eliminating within the subsystem, we have the following expression, similar to the oscillating equation: (20) Now we introduce the imaginary frequency difference. The concept of virtual frequency difference for the entire network is defined as follows: (twenty one) Where k is the association set All nodes belonging to the DC subsystem. We will use This represents the vector of average voltage of the DC subsystem. The converter interconnecting the AC bus i and the DC subsystem k is represented as: (twenty two) Where m is a positive coefficient. Similar to the main controller (7), we control the AC frequency of the interconnect converter instead of directly controlling the power transmission.

[0049] In some embodiments, the method further includes controlling the interconnect converter using a preset distributed averaging algorithm model.

[0050] The preset distributed averaging algorithm model is as follows: , , in, The positive time constant in the diagonal matrix. A column vector of synchronization variables. The derivative of the synchronous communication variable. Let K be the inverse matrix of cost coefficients, and K be the diagonal matrix of positive coefficients. For the imaginary frequency difference of the hybrid power grid, For the Laplace operator, This is the generator power vector.

[0051] In this embodiment, a common method for achieving optimal power sharing in secondary control is to introduce a synchronization communication variable ξ and update these values ​​using a distributed averaging algorithm for an undirected connected communication graph. Specifically, we use... This diagram represents the graph, where Let L represent the set of communication links. The Laplace operator, which is defined as (twenty three) Where deg(i) represents the degree of node i. The distributed controller for the hybrid AC / DC system is designed as follows: (twenty four) (25) In the formula, Let ξ be the positive time constant in the diagonal matrix, and let ξ be the synchronization variable. column vectors, The cost coefficient inverse matrix is ​​the same as before, and K is a diagonal matrix of positive coefficients used to improve performance and determine the power contribution of each generator within the main time frame. Proportional terms. It is an effective primary (drooping) controller, while the slower secondary term... Integrating frequency and average voltage deviation into a steady-state value of zero results in optimal power sharing.

[0052] This controller uses a DC bus voltage weighted by the associated capacitors to capture the dynamics of the subsystem's physical energy, as shown in equation (26). There may be low-capacitance bus voltages that are significantly lower than the reference voltage, but still satisfy the following conditions: Because they respond faster. However, such small voltage deviations on the bus can still be maintained in two ways. First, the steady-state DC bus voltage must still satisfy the power flow equation. This is a capacitance-independent constraint that can potentially limit large voltage deviations (which will depend on the power flow and line resistance). Second, virtual capacitance... The derivative term in DC source dynamics can be easily added to any DC source bus j, for example: (26) The addition of the derivative term will not affect The steady-state value is thus preserved, thereby preserving its optimality.

[0053] The distributed controller proposed in this invention is implemented in a DC subgrid using voltage measurements only within that subgrid and is also fully distributed across the AC subgrids of the network. Importantly, relaxation (9) is achieved by a fully distributed controller that uses only local voltage measurements without additional information transmission, while preserving the stability and optimality presented. This is a very important issue because it would distort the synchronization of the communication variable ξ required for optimal power sharing.

[0054] The equilibrium of systems (1) and (2) with control schemes (12), (13), and (16) resolves the issue that power sharing among all power sources should be optimal. When controllers (12), (13), and (16) are applied to the global minimum of power sharing among the power sources, the solutions for dynamical systems (1) and (2) are locally convergent. Furthermore, it guarantees that the frequency returns to its reference value upon equilibrium, i.e. And ensure that the average voltage deviation of each DC subsystem is zero, that is .

[0055] Consider the dynamical system described in (1) and (2) with control schemes (12), (13), and (16). Then, there exists an open neighborhood of this equilibrium point such that all solutions to (1), (2), (12), (13), and (16) converge from this neighborhood to a set of equilibrium points that solve for power sharing, where... , .

[0056] Stability analysis and theorem proof: 1. Construct Lyapunov functions

[0057] in: , , , here It is the generator inertia matrix. Related to line parameters, It is a DC bus capacitor matrix. It is the corresponding frequency vector. It is an angle difference vector. This is a DC voltage vector; the asterisk (*) indicates the balanced value. In the middle, DC bus capacitor matrix It is related to the DC-side capacitor energy, which reflects the impact of DC-side capacitor voltage changes on the system energy state, and thus affects system stability.

[0058] 2. Analyze the system stability by differentiating the Lyapunov function: beg The derivative, by adding converter bus-related terms (whose values ​​are zero) and rearranging using the balance condition, yields an expression containing power and frequency-related terms. This step primarily analyzes the relationship between AC-side power and frequency in the system dynamics, preparing for subsequent correlation with DC-side capacitor energy-related terms.

[0059] beg The derivative, combined with the equilibrium condition, yields an expression related to the power transfer term, which is used to subsequently offset part of the power term.

[0060] beg The derivative, derived from the definition and known relationships, yields an expression that includes DC-side power, voltage deviation, and the conductance matrix (related to the DC line conductance), and utilizes the VSC controller relationship. Further processing of related items is needed. Specifically, ,because It is a conductance matrix and m>0, so This demonstrates the impact of the DC-side capacitor voltage on the system's energy dissipation through the conductance matrix, while This relationship links the voltage related to the DC-side capacitor energy to the AC-side power transmission.

[0061] Based on the above derivative results, substituting each term into... The expression, after simplification and rearrangement, yields:

[0062] in: Yes The relevant diagonal matrix, D is the damping coefficient matrix. In this process, the DC-side capacitor energy passes through... C in and with The related derivations affect the expressions, and thus the judgment of system stability.

[0063] According to LaSalle's theorem, by roll out And thus obtain and other related variables (such as The convergence of the DC capacitor energy demonstrates that the system converges to the equilibrium point set. During this convergence process, the DC capacitor energy plays a crucial role, indirectly affecting frequency regulation by influencing system stability and providing a stable system environment for steady-state power distribution. For example, when the system is subjected to a disturbance, the change in DC capacitor energy causes a change in V, which in turn affects the equilibrium point set through the aforementioned relationship. By controlling variables such as frequency regulation, the system eventually returns to stability, achieving frequency regulation and tending towards steady-state power distribution.

[0064] Starting from the equilibrium condition, analyze the situation when the resistance of the DC line is arbitrarily small. With balanced frequency The relationship (based on the voltage difference and conductance relationship under equilibrium conditions). In this process, the DC-side capacitor voltage V changes with the AC frequency. The association ( This affects the determination of the frequency in the system's equilibrium state, and thus affects the power distribution.

[0065] By solving the relevant equations under equilibrium conditions, such as: and , This involves power vectors , , , and And so on, and taking advantage of lossless network conditions ( , ),get: (where is a constant), thus leading to: , This proves that the power allocation is close to the solution of the optimization problem (4). During the solution of these equations, parameters related to the DC-side capacitor energy (such as the role of m in the relationship with frequency and voltage) affect the frequency. Indirectly affects power distribution The calculation results. For example, the size of m will affect... The degree of correlation with V plays a key role in solving power allocation and achieving improved steady-state power allocation.

[0066] By analyzing the controller-related equations in equilibrium, such as from... In steady state roll out ( For node j The same equilibrium value), combined with the equilibrium condition, yields the optimal solution for power allocation, indicating that the distributed controller utilizes the energy of the DC capacitor (through... The effectiveness of achieving optimal power sharing (and related parameters) is assessed.

[0067] Constructing Lyapunov functions (such as...) And perform derivative analysis, by analyzing each term of the derivative (including the processing of DC capacitor energy-related terms, such as...) Part of it is related to DC voltage, and DC voltage is passed through... (Related to DC capacitor energy), combined with LaSalle's theorem, the conclusion is drawn that the system converges to the optimal state, further illustrating the effectiveness of the distributed control strategy in utilizing DC capacitor energy to achieve optimal frequency and voltage regulation and power sharing, ensuring stable system operation and achieving optimal performance.

[0068] In the above implementation process, the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem are obtained; the DC voltage of the DC subsystem is acquired in real time; based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, a preset controller model is used to control the interconnect converter to control the frequency of the AC subsystem. By proportionally correlating the AC frequency with the DC voltage, changes in the DC-side capacitor voltage can directly affect the AC-side frequency, thereby allowing the DC capacitor energy to participate in the dynamic adjustment of the system. This control method does not directly control power transmission, but involves the frequency and voltage of the AC and DC sides respectively. This not only improves the accuracy of power sharing, but also provides a fast response to AC interference through capacitive inertia, ensuring that the AC system frequency and the average DC bus voltage of each DC system converge to the reference value, and the system can achieve optimal power distribution even in steady state. Distributed control achieves improved steady-state power distribution and primary frequency regulation by utilizing the energy stored in the DC-side capacitor. By employing a pre-defined distributed averaging algorithm model to control the interconnected converter, the frequency and weighted average voltage of the DC subgrid can be adjusted to specified reference values ​​under steady-state conditions, ensuring the convergence of the AC system frequency and the weighted average DC voltage of each DC subsystem with their reference values. Furthermore, power sharing among all power sources should be optimal. Additionally, virtual capacitors in the controller can be used to further improve performance.

[0069] In some embodiments, it also includes: First, the current frequency of the AC subsystem is acquired in real time; Then, based on the frequency reference value of the DC subsystem, the voltage reference value of the AC subsystem, and the current frequency, a preset controller model is used to control the interconnect converter in order to control the DC voltage of the DC subsystem.

[0070] In this real-time example, the inertia of the AC system can also be used to regulate the DC voltage when appropriate. The above control process is similar to the process described above of controlling the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, and will not be repeated here.

[0071] Figure 1This is a flowchart illustrating the hybrid power grid control method in this embodiment. It should be understood that, although... Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0072] This embodiment provides a hybrid power grid control system, including a controller, an AC subsystem, and a DC subsystem. The AC subsystem and the DC subsystem are connected via an interconnect converter. The controller uses the hybrid power grid control method described above to control the interconnect converter.

[0073] In the above implementation, by proportionally correlating the AC frequency with the DC voltage, changes in the DC-side capacitor voltage directly affect the AC-side frequency, allowing the DC capacitor energy to participate in the dynamic regulation of the system. This control method does not directly control power transmission but involves the frequency and voltage of both the AC and DC sides separately. This not only improves the accuracy of power sharing but also provides a rapid response to AC interference through capacitive inertia, ensuring that the AC system frequency and the average DC bus voltage of each DC system converge to the reference value, and that the system achieves optimal power distribution even in steady state. Distributed control utilizes the energy stored in the DC-side capacitors to achieve improved steady-state power distribution and primary frequency regulation. By using a pre-set distributed averaging algorithm model to control the interconnect converter, the frequency and weighted average voltage of the DC subgrid can be adjusted to the specified reference value in steady state, ensuring the convergence of the AC system frequency and the weighted average DC voltage of each DC subsystem with their reference values. Furthermore, power sharing among all power sources should be optimal. In addition, virtual capacitors in the controller can be used to further improve performance.

[0074] Please refer to Figure 5 , Figure 5 This schematically illustrates a structural diagram of a hybrid power grid control device according to an embodiment of the present application. This embodiment provides a hybrid power grid control device for an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnect converter; the device includes a first acquisition module 410, a second acquisition module 420, and a control module 430, wherein: The first acquisition module 410 is used to acquire the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; The second acquisition module 420 is used to acquire the DC voltage of the DC subsystem in real time. The control module 430 is used to control the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, so as to control the frequency of the AC subsystem.

[0075] The control module 430 includes: The first calculation unit is used to calculate the proportionality coefficient based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem. The second calculation unit is used to substitute the proportional coefficient and the DC voltage of the DC subsystem into a preset controller model to obtain the AC frequency of the AC subsystem. The control unit is used to control the AC output terminal of the interconnect converter based on the AC frequency of the AC subsystem, so as to control the frequency of the AC subsystem.

[0076] The hybrid power grid control device includes a processor and a memory. The first acquisition module 410, the second acquisition module 420, and the control module 430 are all stored in the memory as program units. The processor executes the program units stored in the memory to realize the corresponding functions.

[0077] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and hybrid power grid control can be achieved by adjusting kernel parameters.

[0078] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0079] This invention provides a machine-readable storage medium storing a program that, when executed by a processor, implements the hybrid power grid control method.

[0080] This invention provides a processor for running a program, wherein the program executes the hybrid power grid control method during runtime.

[0081] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6As shown in the figure, the computer device includes a processor A01, a network interface A02, a display screen A04, an input device A05, and a memory (not shown) connected via a system bus. The processor A01 provides computing and control capabilities. The memory includes internal memory A03 and a non-volatile storage medium A06. The non-volatile storage medium A06 stores an operating system B01 and a computer program B02. The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 stored in the non-volatile storage medium A06. The network interface A02 is used for communication with external terminals via a network connection. When the computer program is executed by the processor A01, it implements a hybrid power grid control method. The display screen A04 can be a liquid crystal display (LCD) or an e-ink display. The input device A05 can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0082] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0083] In one embodiment, the hybrid power grid control method apparatus provided in this application can be implemented as a computer program, and the computer program can be implemented in the form of, for example, Figure 6 The computer device shown runs on this device. The computer device's memory can store the various program modules that make up the hybrid power grid control method apparatus, for example, Figure 5 The first acquisition module 410, the second acquisition module 420, and the control module 430 are shown. The computer program comprised of these modules causes the processor to execute the steps of the hybrid power grid control method described in the various embodiments of this application.

[0084] Figure 6 The computer device shown can be used as follows Figure 5 The first acquisition module 410 in the hybrid power grid control method device shown executes step 210. The computer device can execute step 220 via the second acquisition module 420. The computer device can execute step 230 via the control module 430.

[0085] This application provides an electronic device comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the at least one processor implements the aforementioned hybrid power grid control method by executing the instructions stored in the memory, for an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnect converter; the processor executes the instructions to perform the following steps: Obtain the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; The DC voltage of the DC subsystem is acquired in real time. Based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, a preset controller model is used to control the interconnect converter in order to control the frequency of the AC subsystem.

[0086] In one embodiment, controlling the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage to control the frequency of the AC subsystem includes: Based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem, the proportionality coefficient is calculated. Substituting the proportional coefficient and the DC voltage of the DC subsystem into the preset controller model, the AC frequency of the AC subsystem is obtained. Based on the AC frequency of the AC subsystem, the AC output terminal of the interconnect converter is controlled to control the frequency of the AC subsystem.

[0087] In one embodiment, the preset controller model is: , in , The AC bus connected to the interconnect converter is used The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: The set of DC buses connected to the interconnect converter is represented as follows: , For AC bus, It is a DC bus. This is the proportionality coefficient. The DC voltage of the DC bus in the DC subsystem is given. The frequency of the AC bus in the AC subsystem is given.

[0088] In one embodiment, the preset controller model is a distributed controller, and the distributed controller is: , Among them, The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: , For AC bus, This is the proportionality coefficient. This is the average voltage of all nodes in the DC subsystem. The frequency of the AC bus in the AC subsystem is given.

[0089] In one embodiment, the method further includes: The interconnect converter is controlled using a pre-set distributed averaging algorithm model.

[0090] In one embodiment, the pre-defined distributed averaging algorithm model is: , , in, The positive time constant in the diagonal matrix. A column vector of synchronization variables. The derivative of the synchronous communication variable. Let K be the inverse matrix of cost coefficients, and K be the diagonal matrix of positive coefficients. For the imaginary frequency difference of the hybrid power grid, For the Laplace operator, This is the generator power vector.

[0091] In one embodiment, it also includes: The current frequency of the AC subsystem is obtained in real time; Based on the frequency reference value of the DC subsystem, the voltage reference value of the AC subsystem, and the current frequency, a preset controller model is used to control the interconnect converter in order to control the DC voltage of the DC subsystem.

[0092] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0093] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations 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 apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0094] These computer program instructions may also be stored in a computer-readable storage medium that can direct 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, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0095] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0096] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0097] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0098] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0099] It should also be noted that 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 process, method, article, or apparatus. Unless otherwise specified, 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 that element.

[0100] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A hybrid power grid control method, characterized in that, For an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnect converter; the method includes: Obtain the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; The DC voltage of the DC subsystem is acquired in real time. Based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, a preset controller model is used to control the interconnect converter in order to control the frequency of the AC subsystem.

2. The hybrid power grid control method according to claim 1, characterized in that, The control of the interconnect converter using a preset controller model, based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, to control the frequency of the AC subsystem includes: Based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem, the proportionality coefficient is calculated. Substituting the proportional coefficient and the DC voltage of the DC subsystem into the preset controller model, the AC frequency of the AC subsystem is obtained. Based on the AC frequency of the AC subsystem, the AC output terminal of the interconnect converter is controlled to control the frequency of the AC subsystem.

3. The hybrid power grid control method according to claim 2, characterized in that, The preset controller model is as follows: ， in , The AC bus connected to the interconnect converter is used The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: The set of DC buses connected to the interconnect converter is represented as follows: , For AC bus, It is a DC bus. This is the proportionality coefficient. The DC voltage of the DC bus in the DC subsystem is given. The frequency of the AC bus in the AC subsystem is given.

4. The hybrid power grid control method according to claim 2, characterized in that, The pre-defined controller model is a distributed controller, and the distributed controller is as follows: ， Among them, The DC bus connected to the interconnect converter is used The set of AC buses connected to the interconnect converter is represented as follows: , For AC bus, This is the proportionality coefficient. This is the average voltage of all nodes in the DC subsystem. The frequency of the AC bus in the AC subsystem is given.

5. The hybrid power grid control method according to claim 4, characterized in that, The method further includes: The interconnect converter is controlled using a pre-set distributed averaging algorithm model.

6. The hybrid power grid control method according to claim 5, characterized in that, The pre-defined distributed averaging algorithm model is as follows: ， ， in, The positive time constant in the diagonal matrix. A column vector of synchronization variables. The derivative of the synchronous communication variable. Let K be the inverse matrix of cost coefficients, and K be the diagonal matrix of positive coefficients. For the imaginary frequency difference of the hybrid power grid, For the Laplace operator, This is the generator power vector.

7. The hybrid power grid control method according to claim 1, characterized in that, Also includes: The current frequency of the AC subsystem is obtained in real time; Based on the frequency reference value of the DC subsystem, the voltage reference value of the AC subsystem, and the current frequency, a preset controller model is used to control the interconnect converter in order to control the DC voltage of the DC subsystem.

8. A hybrid power grid control device, characterized in that, For an AC / DC hybrid network, the AC / DC hybrid network including an AC subsystem and a DC subsystem, the AC subsystem and the DC subsystem being connected via an interconnect converter; the device includes: The first acquisition module is used to acquire the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem; The second acquisition module is used to acquire the DC voltage of the DC subsystem in real time. The control module is used to control the interconnect converter using a preset controller model based on the frequency reference value of the AC subsystem, the voltage reference value of the DC subsystem, and the DC voltage, so as to control the frequency of the AC subsystem.

9. The hybrid power grid control device according to claim 8, characterized in that, The control module includes: The first calculation unit is used to calculate the proportionality coefficient based on the frequency reference value of the AC subsystem and the voltage reference value of the DC subsystem. The second calculation unit is used to substitute the proportional coefficient and the DC voltage of the DC subsystem into a preset controller model to obtain the AC frequency of the AC subsystem. The control unit is used to control the AC output terminal of the interconnect converter based on the AC frequency of the AC subsystem, so as to control the frequency of the AC subsystem.

10. A hybrid power grid control system, characterized in that, It includes a controller, an AC subsystem, and a DC subsystem, wherein the AC subsystem and the DC subsystem are connected via an interconnect converter, and the controller controls the interconnect converter using the hybrid power grid control method described in claims 1-7.

11. An electronic device, characterized in that, The electronic device includes: At least one processor; A memory connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the hybrid power grid control method according to any one of claims 1 to 7 by executing the instructions stored in the memory.

12. A machine-readable storage medium storing instructions thereon, characterized in that, When executed by a processor, this instruction causes the processor to be configured to perform the hybrid power grid control method according to any one of claims 1 to 7.

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