A microgrid voltage control method and device

Abstract

This invention provides a microgrid voltage control method and apparatus, relating to the field of power grid control technology. The method includes: constructing the operating space of the microgrid; constructing a multi-dimensional pipeline based on the operating space, the multi-dimensional pipeline representing the safe operating domain of the microgrid; generating a central path of the multi-dimensional pipeline, the central path representing the rated operating state of the microgrid; and controlling the microgrid voltage so that the actual operating state of the microgrid tends towards the central path and falls within the multi-dimensional pipeline. This invention, by constructing a high-dimensional pipeline to achieve voltage control constraints, ensures that all actual operating states of the microgrid are within the safe and stable operating space of the microgrid, thereby guaranteeing the safe operation of the microgrid and improving the speed and efficiency of control and regulation.

Description

Technical Field

[0001] This invention relates to the field of power grid control technology, and specifically to a microgrid voltage control method and device. Background Technology

[0002] Microgrids are small, independently operating power systems that enable the local consumption of renewable energy, improving the reliability and economy of the power system. However, with the large-scale integration of distributed power sources such as photovoltaics and energy storage, microgrids face technical challenges such as complex voltage control and difficulty in guaranteeing system stability.

[0003] In the field of microgrid voltage control, existing technologies include centralized control and local control methods. Centralized control relies on a central controller to uniformly schedule and control the entire microgrid. While centralized control can achieve global optimization, it suffers from high communication latency and slow response speed, making it difficult to cope with the rapid response requirements of dynamic scenarios such as sudden changes in sunlight and sharp load increases. Local control methods (such as reactive power compensation control measurement based on droop control) can achieve fast response, but lack multi-node coordination mechanisms, which can easily lead to regulation conflicts and equipment overload. Summary of the Invention

[0004] To address the problems in the prior art, embodiments of the present invention provide a microgrid voltage control method and apparatus, which can at least partially solve the problems existing in the prior art.

[0005] On one hand, embodiments of the present invention provide a microgrid voltage control method, comprising: Constructing the operating space for microgrids; A multi-dimensional pipeline is constructed based on the operating space, and the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. Generate the central path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid; Control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

[0006] In some embodiments, the interaction strength between distributed energy sources in a microgrid can be determined based on the microgrid topology; a decoupled dynamic model of the distributed power source can be constructed based on the interaction strength; the critical energy surface can be determined based on the energy function of the distributed power source that matches the decoupled dynamic model; the entropy index of the distributed power source can be obtained; and the operating space of the microgrid can be constructed based on the entropy boundary conditions and the critical energy surface corresponding to the entropy index.

[0007] In some embodiments, the gain matrix of the control variable of the distributed power source relative to the controlled variable can be calculated; the interaction between the distributed power sources can be evaluated based on the gain matrix to obtain the interaction strength; the distributed power sources that need to be ignored and those that need to be decoupled can be determined based on the interaction strength; and the decoupling dynamic model of the distributed power source can be constructed based on the equivalent decoupling power of the distributed power source.

[0008] In some embodiments, the energy function of the distributed power source can be established based on the decoupled dynamic model of the distributed power source; the energy value of the dominant unstable equilibrium point can be selected as the critical energy based on the energy function of the distributed power source; and the critical energy can be fitted to obtain the critical energy surface.

[0009] In some embodiments, the safe operating region of each distributed power source can be defined on the power plane according to the entropy boundary condition; the operating space can be constructed by projecting the safe operating region onto the three-dimensional critical energy surface.

[0010] In some embodiments, voltage trajectory optimization can be performed with the operating space as a constraint to obtain the voltage operating trajectory; and a multi-dimensional pipeline that can adaptively change with the entropy index can be constructed with the voltage operating trajectory as the center and using the entropy index of the distributed power source.

[0011] In some embodiments, the multidimensional pipeline center path can be generated by the main controller; the voltage of the microgrid can be controlled by the auxiliary controller so that the operating state of the microgrid tends to the center path and is within the multidimensional pipeline.

[0012] On the other hand, the present invention provides a microgrid voltage control device, comprising: The first building unit is used to construct the operating space of the microgrid; The second construction unit is used to construct a multi-dimensional pipeline based on the operating space, wherein the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. A generation unit is used to generate the central path of the multidimensional pipeline, the central path being used to characterize the rated operating state of the microgrid. The control unit is used to control the voltage of the microgrid so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

[0013] On the other hand, embodiments of the present invention provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described microgrid voltage control method.

[0014] On the other hand, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described microgrid voltage control method.

[0015] On the other hand, embodiments of the present invention provide a computer program product, the computer program product including a computer program, which, when executed by a processor, implements the above-described microgrid voltage control method.

[0016] The technical solutions of the embodiments in this specification can construct the operating space of a microgrid; construct multi-dimensional pipelines based on the operating space, the multi-dimensional pipelines being used to characterize the safe operating domain of the microgrid; generate a central path for the multi-dimensional pipelines, the central path being used to characterize the rated operating state of the microgrid; and control the microgrid voltage so that the actual operating state of the microgrid tends towards the central path and is within the multi-dimensional pipelines. Therefore, the embodiments of this specification, by constructing high-dimensional pipelines to achieve voltage control constraints, ensure that all actual operating states of the microgrid are within the safe and stable operating space of the microgrid, thereby guaranteeing the safe operation of the microgrid. Furthermore, it can also make the actual operating state of the microgrid tend towards the central path of the high-dimensional pipelines, thereby improving the overall dynamic performance of the microgrid. The control of the embodiments of this specification focuses more on the stability and orderliness of the microgrid itself, can meet the voltage control requirements under various complex operating scenarios, can significantly improve the response speed and stability of microgrid voltage control, and is applicable to dynamic voltage adjustment in scenarios with high penetration of distributed energy. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 A flowchart illustrating a microgrid voltage control method provided in the embodiments of this specification; Figure 2 A schematic diagram of a voltage control process provided in the embodiments of this specification; Figure 3 This is a functional structure diagram of a microgrid voltage control device provided in the embodiments of this specification; Figure 4 This is a functional structure diagram of a computer device provided as an embodiment of this specification. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0019] Please see Figure 1 and Figure 2 This specification provides a microgrid voltage control method applied to computer equipment. The method can be used for real-time autonomous control of microgrid voltage and specifically includes the following steps.

[0020] Step S1: Construct the operating space of the microgrid.

[0021] In some embodiments, a microgrid is a small-scale power system capable of independent operation, enabling local consumption of renewable energy and improving the reliability and economy of the power system. A microgrid may include distributed power sources such as photovoltaic power generation systems, wind turbines, micro gas turbines, and fuel cells; energy storage devices such as batteries and supercapacitors; and energy management systems, monitoring and protection devices, and loads. Based on the microgrid's topology, the interaction strength between distributed energy sources in the microgrid can be determined; based on the interaction strength, the microgrid can be decoupled to construct a decoupled dynamic model of the distributed power sources; the energy function of the distributed power sources can be constructed based on the decoupled dynamic model; the critical energy at different operating points can be solved based on the energy function of the distributed power sources to obtain the critical energy surface; the entropy index of the distributed power sources can be obtained; the entropy boundary conditions corresponding to the entropy index can be obtained; and the safe operating region defined by the entropy boundary conditions can be mapped to the stable boundary defined by the critical energy surface, thereby constructing the operating space of the microgrid.

[0022] In some embodiments, the topology of a microgrid can refer to the physical connections between electrical devices (such as distributed generation sources, energy storage devices, loads, switches, etc.) within the microgrid. An undirected graph can be constructed based on the microgrid's topology. An undirected graph can describe the connections between distributed generation sources. For example, an undirected graph includes multiple nodes and edges between nodes. Nodes represent electrical devices (e.g., distributed generation sources) within the microgrid. Edges represent the physical connections between these electrical devices. Considering the topology, the injected power of a distributed generation node can be described by a node power equation, which can be expressed as: , P represents active power, Q represents reactive power, and A represents the directed correlation matrix. Z v This represents the branch impedance parameter matrix. δ Represents the voltage phase angle vector. B represents the nodal admittance matrix. ii Represents the off-diagonal elements in the admittance matrix. V This represents the node voltage magnitude vector. The node admittance matrix is ​​a mathematical model used in power networks to describe the linear relationship between node voltage and injected current. Injected power can be represented as the net power actually injected by a distributed generation node into its associated branches to maintain microgrid balance, taking into account the actual topology of the microgrid, branch impedance parameters, etc.

[0023] In some embodiments, the gain matrix of the control variable (e.g., reactive power) relative to the controlled variable (e.g., voltage) in a microgrid can be calculated. The gain matrix represents the interaction strength between different control loops (different distributed power sources). The gain matrix includes multiple elements. The elements in the gain matrix represent the interaction (or coupling) strength between distributed power source nodes. Thus, the interaction strength between various distributed power sources in the microgrid can be obtained from the gain matrix. Based on the interaction strength, distributed power sources with negligible interactions and those with non-negligible interactions can be identified; for distributed power sources with non-negligible interactions, the equivalent decoupling power can be calculated based on the transfer function relationship; and a decoupling dynamic model of the distributed power sources can be constructed based on the equivalent decoupling power.

[0024] Distributed power sources in a microgrid have multiple variables. These variables can include control variables and controlled variables; control variables include reactive power, etc., while controlled variables include voltage, etc. n The elements in the gain matrix of a microgrid with distributed power sources. It can be represented as . This can represent distributed power sources. i With distributed power j The strength of the interaction between them. Indicates control variables, Distributed power sources i The control variables, Distributed power sources j The control variables, Represents the controlled variable. Distributed power source i The controlled variable, Distributed power sources j The controlled variable is 0≤i≤n, 0≤j≤n, where i and j are both positive numbers. i and j can be equal or unequal. . G i ( s () indicates distributed power sourcei Closed-loop transfer function acting alone. Control variables With the controlled variable The relative gain matrix can be expressed as .

[0025] If the interaction strength of two distributed power sources falls within a first numerical range, it can be determined that there is a strong interaction between the two distributed power sources, and their mutual influence cannot be ignored. If the interaction strength of the two distributed power sources falls within a second numerical range, it can be determined that the interaction between the two distributed power sources is weak, and their mutual influence can be ignored. For example, the first numerical range is... The second numerical range is . . Distributed power sources i With distributed power j The strength of the interaction. Indicate whether distributed power sources can be ignored. i With distributed power j The interaction between them.

[0026] neglect Interactions between distributed power sources with a value of 0 are preserved. For the interaction between distributed power sources with a value of 1, the transfer function of the stable branch state variable of distributed power source node i can be expressed as: . J ij ( s () indicates distributed power source i With distributed power j Network transfer functions between them Δ x j ( s (Distributed power source) j Control variable disturbance, Δ S i ( s (Distributed power source) i The response of the controlled variable. Distributed power sources j With distributed power j The mutual coupling between +1. Capable of representing distributed power sources i The dynamic coupling relationship of the controlled variable (such as voltage) is formed by the linear superposition of its own control action and network coupling interference.

[0027] To eliminate or reduce the influence of coupling interference terms, the equivalent decoupling power of distributed source i can be determined based on the transfer function of the steady branch state variables of distributed source i. Based on the equivalent decoupling power, a decoupling dynamic model of distributed power sources can be constructed. . x t These are system state variables, including the frequency and phase angle states within the phase-locked loop, the states of the inner and outer loop PI controllers, the states of the filter inductors and capacitors, the DC voltage states, and the decoupled state variables. y t For algebraic variables, the active power at the steady-state operating point of the distributed generation is included. P reactive power Q , This is a disturbance quantity. For example, it can couple the network to the power supply. i The effect of stable branch transfer function M i ( s) Equivalent to decoupled power input Then inject that equivalent power into the power supply. i The single-machine dynamic equations (including PLL, inner and outer loop PI, filters, DC side, etc.) are obtained and then linearized / state-spaced using small-signal linearization, resulting in the form: The decoupled dynamic model.

[0028] In some embodiments, the energy function of the distributed power source can be established based on the decoupled dynamic model of the distributed power source; the energy value of the dominant unstable equilibrium point can be selected as the critical energy based on the energy function of the distributed power source; and the critical energy can be fitted to obtain the critical energy surface.

[0029] Key states can be selected based on the decoupled dynamic model of distributed power sources. And write it in a structure-preserving form: , , The potential energy term can be obtained by first integrating the power angle and voltage channels, and the kinetic energy term can be constructed by integrating the frequency channels, thus forming the energy function of the distributed source. The energy function is used for transient energy. Based on the energy function construction of the distributed source, the homotopy method is used to solve for the dominant unstable equilibrium point. Specifically, let... Introducing parameters t and auxiliary functions Thus establishing homotopy mapping And solve it. Among them, x r0 yes x r The initial value is used to define the initial conditions. x r(0). Find the dominant unstable equilibrium point. The energy value corresponding to the dominant unstable equilibrium point can be used as the critical energy. E cr If the energy of the distributed power source exceeds the critical energy... E cr If the condition is deemed unstable, then instability is considered to have occurred. To obtain a continuously usable stability boundary, the above critical energy solution method can be repeated at multiple different steady-state operating points (corresponding to different P and Q values) to calculate a series of critical energy values. This process is repeated for different critical energies calculated at different steady-state operating points. E cr The critical energy surface can be fitted in the power-energy space (PQE) using the hyperplane piecewise affine fitting method.

[0030] To achieve the above fitting efficiently and reliably, a two-stage solution model can be established using the critical energy as the boundary value to characterize the critical energy surface. The two-stage solution model includes an inner model and an outer model. The inner model is used to determine the stability of the system (microgrid) based on boundary condition constraints. The outer model searches for boundary points along the power growth direction until the system loses stability, and takes the previous boundary point as the critical stability point. The inner model needs to determine the operating conditions for solution, and the limit of the outer model is constrained by the stability margin of the inner model. The critical energy surface includes multiple critical stability hyperplanes, and the fitting function of the critical energy surface is expressed as... . Distributed power sources i The steady-state operating point, g It is a polynomial function, usually of order 2-3.

[0031] In some embodiments, a system entropy index can be constructed to characterize the power flow balance and static voltage safety of a microgrid. This system entropy index can be decomposed and allocated to each distributed generation node to obtain a distributed generation entropy index. The distributed generation entropy index represents the contribution of a single distributed generation to the system's power flow balance and static voltage safety; that is, whether the local operating state of the power source leads to a more uneven power flow distribution or a more concentrated risk of voltage exceedance. For example, a branch delimitation / node affiliation method can be used to divide the statistical objects in the system entropy calculation (e.g., branch load rate interval counts, node voltage deviation interval counts) according to the set of branches / nodes connected to or affected by the power source. Within this subset, the power source-level probability and corresponding entropy value are recalculated or weighted to form a power source-level entropy index. The distributed generation entropy index used to characterize power flow balance and static voltage safety can be expressed as follows: . These are the power flow balance entropy index and the voltage safety entropy index, respectively. These represent the weights. The entropy boundary conditions can be determined based on the distributed power source entropy index. The entropy boundary conditions of a distributed power source can be expressed as follows: Based on the entropy index and entropy boundary conditions, in two-dimensional power ( PQ Construct the entropy boundary of distributed sources on the two-dimensional power plane; based on the fitted critical energy surface, the entropy boundary of distributed sources in the two-dimensional power plane can be projected onto the three-dimensional plane. PQE On the critical energy surface in the (active power - reactive power - energy) space, the projected microgrid operating space can be represented as: , . This represents the critical energy surface. The entropy boundary condition is used to define the microgrid operating space, which refers to the feasible operating region in the PQE space that simultaneously satisfies static safety order (entropy constraint) and dynamic stability margin (critical energy constraint). It characterizes the set of operating points where the microgrid can operate safely and stably under disturbances. Therefore, by integrating and mapping the safe operating regions of each node on the two-dimensional power plane (defined by the entropy boundary condition) onto the three-dimensional power-energy space defined by the critical energy surface, the resulting three-dimensional subspace is the microgrid operating space.

[0032] Step S2: Construct a multi-dimensional pipeline based on the operating space. The multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid.

[0033] In some embodiments, voltage trajectory optimization can be performed with the microgrid operating space as a constraint to obtain an optimized voltage operating trajectory; and a multi-dimensional pipeline that can adaptively change with the entropy index can be constructed using the voltage operating trajectory as the center and the entropy index of distributed power sources.

[0034] In some embodiments, a discrete state-space model of a microgrid system can be constructed: , . , , These are the state variables, control variables, and output disturbances, respectively. Consider a sequence of independent disturbance variables. and They respectively follow probability distribution P[ w ] and P[ v Based on a discrete model, the microgrid system can be represented as a Markov decision process (Markov model). Based on the Markov decision process, the next time step state of the microgrid system... x t+1 Can be determined from the current state x t and control input u t Decision. In practical applications, this can be achieved through vectors. Indicates to t All system information available at any time. This represents all output voltages up to time t. This represents all control commands up to time t. In a given I t At that time, state x t posterior probability distribution It can be calculated using the recursive Bayesian estimation method. , .

[0035] by and They represent the random states respectively. x t In random variables w k and v k The expected value and probability of the event under the influence. N Represents the predicted time domain of the voltage trajectory, and the corresponding N The step control sequence can be represented as The objective function for trajectory optimization can be expressed as minimizing the expected cost. The objective function represents the direction of voltage trajectory evolution. The optimization problem must satisfy the opportunity constraints within the operating space (entropy-space opportunity constraints). By solving this optimization problem, the voltage operating trajectory that satisfies the safety operation constraints can be obtained.

[0036] In some embodiments, the operating state of a microgrid under conditions such as renewable energy generation, load consumption, and entropy distribution can be characterized and constrained by a high-dimensional polyhedral pipeline. The multidimensional pipeline can be represented as... . Let be the compact fundamental set of distributed source voltages under entropy constraints, representing the set of voltages of a given distributed source under a given entropy. H The constraint range within which the system state is allowed to change; matrix sum vector The coefficients are set-parameterized. n and m Let C and c represent the number of rows and columns of the matrix, respectively. Since the coefficient matrix C and coefficient vector c are of finite dimension, this fundamental set... It can be pre-computed and stored in the controller's memory. For example, if the basic set If stored as an interval, then the cell interval can be used as the base set. In this case, the coefficient vector cIt can serve as the center of the foundation set, used to represent the rated operating state of a microgrid. Coefficient matrix. C It is nonnegative and a diagonalized matrix. The diagonal terms of the coefficient matrix C can represent the width of the pipe along different coordinate axes. Alternatively, if a more general coefficient matrix is ​​used... C (Not necessarily a diagonal matrix), then non-coordinate aligned intervals can be constructed through rotational transformations, thus forming a more adaptable pipe shape. To achieve adaptive parameter adjustment, the following parameterized coefficient function can be further constructed: , . For conversion gain. For a properly designed basis set, the robust invariant set of a microgrid system can be expressed as: , This ensures that as long as the current state is within the pipe, under the influence of system dynamics and control laws, the state at the next moment will remain within the updated pipe, thus providing a provable robust safety guarantee for the closed-loop system.

[0037] Step S3: Generate the central path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid.

[0038] Step S4: Control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

[0039] In some embodiments, the multidimensional pipeline center path can be generated by the main controller; the voltage of the microgrid can be controlled by the auxiliary controller so that the operating state of the microgrid tends to the center path and is within the multidimensional pipeline.

[0040] The microgrid voltage control method is implemented through a master-slave controller architecture. The master controller and the slave controller work collaboratively. Based on a high-dimensional pipeline representing the microgrid's operating state, two model predictive controllers are used to track the control objective. These two model predictive controllers include a master controller and a slave controller, and the control objective can include the voltage of distributed power sources. The master controller generates the central path of the pipeline representing the microgrid's rated operating state, while the slave controller controls the microgrid under uncertain disturbances within the edge of the pipeline, thus forming a control framework that tends towards the center of the pipeline.

[0041] A robust forward-invariant pipeline construction method can be used here to ensure the stability of closed-loop control. A set-valued function is defined. If a feedback control law exists , so that: If the set-valued function is such that the set-valued function is called a robust forward-invariant pipeline, then the set-valued function is called a robust forward-invariant pipeline. For all t 1, t 2 , andt 1< t 2, and use This indicates that the dynamic system is in time [0, ... T The set of all robust forward-invariant pipes on [the network]. Furthermore, considering that perturbations cause the entropy distribution to have probabilistic characteristics, the system state can be described by a probabilistic description: Extending this description to the prediction time domain, it can be expressed as: The master controller optimization problem for pipeline model prediction, considering the probabilistic characteristics of disturbances, can then be expressed as: z t As a reference state for the center path of the pipeline, u t This serves as the control input for the main controller. Therefore, the optimization problem of the main controller can be formulated as finding the optimal center path and corresponding control sequence under probabilistic constraints. The main controller uses a high-dimensional polyhedral pipeline as the safety constraint set and generates the pipeline center path (i.e., the rated operating state trajectory or nominal state trajectory) by rolling the solution of the predictive optimization problem.

[0042] The control objective of the auxiliary controller can be set as tracking the trajectory generated by the main controller, ensuring that the actual voltage trajectory remains within the channel centered on the path generated by the main controller under uncertain power, parameter, and other disturbances. Therefore, the optimization problem of the auxiliary controller can be expressed as: .

[0043] As a key component guiding real-time state variables towards optimization, the auxiliary controller reflects the dynamic deviation between the rated state variables and the actual state variables. The dynamic model of this deviation can be expressed as: . A , B 1. B 2 represents the system matrix, disturbance matrix, and control matrix after the model is linearized, respectively. D , F , E 1. E 2 indicates that it is used to construct the system matrix. A and control matrix B The uncertainty part in 2.

[0044] To achieve adaptive adjustment of control parameters with entropy value, the key parameters affecting the controller can be optimized based on the optimization effect of the actual voltage feedback (the effect of controlling the actual voltage to approach the center of the pipeline).

[0045] The optimization process for control parameters may include: 1) Solve the system of linear matrix inequalities. Based on the L2 norm constraint of the key voltage state variables under entropy constraints and robust performance indicators, solve a set of linear matrix inequalities to obtain the feedback gain matrix of the auxiliary controller. This ensures that the closed-loop system meets the requirements for robust stability and dynamic performance.

[0046] 2) Apply static operating constraints. Incorporate physical limits of the actual equipment (such as upper and lower limits of reactive power output, ramp rate, etc.) into the control quantity calculation, and ensure the feasibility of control commands through projection or saturation processing.

[0047] By further considering the static constraints of the actual equipment, the final control effect can be achieved through output limitations.

[0048]

[0049] By controlling the overall feedback process, i.e., real-time centralized acquisition of the status information of each distributed power node in the system, based on the above optimization model and adaptive gain... Centralized computing control commands The commands are then distributed to the local controllers of each distributed power source for execution, achieving a closed-loop dynamic feedback adjustment process. The control commands contain... This is used to control the actual voltage within the area centered on the pipeline. In the overall feedback process described above, voltage information can be collected from the distribution network, control commands can be calculated according to the control strategy, and then sent to the control unit. The control unit outputs power to control the voltage magnitude, thus forming feedback. This process is then repeated at each sampling time.

[0050] Therefore, it is possible to uniformly handle model uncertainties, entropy changes, and equipment constraints at the algorithm level, thereby achieving the goal of dynamic voltage control that adaptively adjusts based on real-time entropy values.

[0051] The technical solutions of the embodiments in this specification can construct the operating space of a microgrid; construct multi-dimensional pipelines based on the operating space, the multi-dimensional pipelines being used to characterize the safe operating domain of the microgrid; generate a central path for the multi-dimensional pipelines, the central path being used to characterize the rated operating state of the microgrid; and control the microgrid voltage so that the actual operating state of the microgrid tends towards the central path and is within the multi-dimensional pipelines. Therefore, the embodiments of this specification, by constructing high-dimensional pipelines to achieve voltage control constraints, ensure that all actual operating states of the microgrid are within the safe and stable operating space of the microgrid, thereby guaranteeing the safe operation of the microgrid. Furthermore, it can also make the actual operating state of the microgrid tend towards the central path of the high-dimensional pipelines, thereby improving the overall dynamic performance of the microgrid. The control in the embodiments of this specification focuses more on the stability and orderliness of the microgrid itself, can meet the voltage control requirements under various complex operating scenarios, and is applicable to dynamic voltage adjustment in scenarios with high penetration of distributed energy resources.

[0052] It should be noted that, in Figure 2 In the middle, P PV (k) represents the active power of the photovoltaic device at time k. and This indicates the active power output limits (minimum and maximum limits) of photovoltaic equipment. and Q represents the reactive power output limits (minimum and maximum limits) of photovoltaic equipment. PV (k) represents the reactive power of the photovoltaic device at time k, P ES (k) represents the active power of the energy storage device at time k. and This indicates the active power output limits (minimum and maximum limits) of the energy storage device. and V represents the reactive power output limits (minimum and maximum limits) of energy storage devices. i (k) represents the voltage magnitude of node i at time k. and This represents the voltage safety limits (minimum and maximum limits) of node i.

[0053] Figure 3 This is a schematic diagram of the microgrid voltage control device provided in the embodiments of this specification, as shown below. Figure 3 As shown in the embodiments of this specification, the microgrid voltage control device includes a first building unit 301, a second building unit 302, a generation unit 303, and a control unit 304.

[0054] The first construction unit 301 is used to construct the operating space of the microgrid. Specifically, the first construction unit 301 is used to determine the interaction strength between distributed energy sources in the microgrid based on the microgrid topology; construct a decoupled dynamic model of the distributed energy sources based on the interaction strength; determine the critical energy surface based on the energy function of the distributed energy sources that matches the decoupled dynamic model; obtain the entropy index of the distributed energy sources; and construct the operating space of the microgrid based on the entropy boundary conditions and critical energy surface corresponding to the entropy index.

[0055] The second construction unit 302 is used to construct a multi-dimensional pipeline based on the operating space, wherein the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. Specifically, the second construction unit 302 is used to optimize the voltage trajectory with the operating space as a constraint to obtain the voltage operating trajectory; and using the voltage operating trajectory as the center, a multi-dimensional pipeline that can adaptively change with the entropy index of the distributed power source is constructed.

[0056] The generation unit 303 is used to generate the center path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid. Specifically, the generation unit 303 is used to generate the center path of the multidimensional pipeline through the main controller.

[0057] The control unit 304 is used to control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and is within the multidimensional pipeline. Specifically, the control unit 304 is used to control the voltage of the microgrid through an auxiliary controller so that the operating state of the microgrid tends to the central path and is within the multidimensional pipeline.

[0058] Figure 4 This is a schematic diagram of the physical structure of a computer device provided in an embodiment of the present invention, such as... Figure 4 As shown, the computer device includes: a memory 401, a processor 402, and a computer program stored in the memory 401 and executable on the processor 402. When the processor 402 executes the computer program, it implements the following method: Constructing the operating space for microgrids; A multi-dimensional pipeline is constructed based on the operating space, and the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. Generate the central path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid; Control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

[0059] This embodiment discloses a computer program product, which includes a computer program that, when executed by a processor, implements the following method: Constructing the operating space for microgrids; A multi-dimensional pipeline is constructed based on the operating space, and the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. Generate the central path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid; Control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

[0060] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the following method: Constructing the operating space for microgrids; A multi-dimensional pipeline is constructed based on the operating space, and the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. Generate the central path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid; Control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

[0061] Compared with existing technologies, the embodiments of this invention can achieve voltage control constraints by constructing a high-dimensional pipeline, ensuring that all actual operating states of the microgrid remain within its safe and stable operating space, thereby guaranteeing the safe operation of the microgrid. Furthermore, it can guide the actual operating state of the microgrid towards the central path of the high-dimensional pipeline, improving the overall dynamic performance of the microgrid. The control measures described in this specification focus more on the stability and orderliness of the microgrid itself, meeting the voltage control requirements of various complex operating scenarios and applicable to dynamic voltage regulation in scenarios with high penetration rates of distributed energy resources.

[0062] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention 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.

[0063] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. 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 illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0064] 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.

[0065] 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 1The steps of the function specified in one or more boxes.

[0066] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A microgrid voltage control method, characterized in that, include: Constructing the operating space for microgrids; A multi-dimensional pipeline is constructed based on the operating space, and the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. Generate the central path of the multidimensional pipeline, which is used to characterize the rated operating state of the microgrid; Control the microgrid voltage so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

2. The method according to claim 1, characterized in that, The operating space for constructing the microgrid includes: Based on the microgrid topology, determine the interaction strength among distributed energy sources in the microgrid; Based on the strength of the interaction, a decoupled dynamic model of the distributed power source is constructed; The critical energy surface is determined based on the energy function of the distributed power source that matches the decoupled dynamic model. Obtain the entropy metric of distributed power sources; The operating space of a microgrid is constructed based on the entropy boundary conditions and critical energy surface corresponding to the entropy index.

3. The method according to claim 2, characterized in that, Determining the interaction strength among distributed energy sources in a microgrid includes: Calculate the gain matrix of the control variable relative to the controlled variable of the distributed power source; The interaction between distributed power sources is evaluated based on the gain matrix to obtain the interaction strength. The construction of the decoupled dynamic model for distributed power sources includes: Based on the strength of the interaction, determine the distributed power sources that should be ignored and those that need to be decoupled; Based on the equivalent decoupling power of distributed power sources, a decoupling dynamic model of distributed power sources is constructed.

4. The method according to claim 2, characterized in that, The determination of the critical energy surface includes: Based on the decoupled dynamic model of distributed power sources, the energy function of distributed power sources is established. Based on the energy function of distributed power sources, the energy value of the dominant unstable equilibrium point is selected as the critical energy. By fitting the critical energy, a critical energy surface is obtained.

5. The method according to claim 2, characterized in that, The operating space for constructing the microgrid includes: Based on the entropy boundary condition, the safe operating area of ​​each distributed power source is defined on the power plane; The operating space is constructed by projecting the safe operating region onto the three-dimensional critical energy surface.

6. The method according to claim 1, characterized in that, The construction of multi-dimensional pipelines based on the operating space includes: Voltage trajectory optimization is performed using the aforementioned operating space as a constraint to obtain the voltage operating trajectory; Centered on the voltage operating trajectory, a multi-dimensional pipeline that can adaptively change with the entropy index of the distributed power source is constructed using the entropy index.

7. The method according to claim 1, characterized in that, The central path for generating the multidimensional pipeline includes: The multidimensional pipeline center path is generated by the main controller; The control of the microgrid voltage includes: The voltage of the microgrid is controlled by an auxiliary controller so that the operating state of the microgrid tends to the central path and within the multidimensional pipeline.

8. A microgrid voltage control device, characterized in that, include: The first building unit is used to construct the operating space of the microgrid; The second construction unit is used to construct a multi-dimensional pipeline based on the operating space, wherein the multi-dimensional pipeline is used to characterize the safe operating domain of the microgrid. A generation unit is used to generate the central path of the multidimensional pipeline, the central path being used to characterize the rated operating state of the microgrid. The control unit is used to control the voltage of the microgrid so that the actual operating state of the microgrid tends to the central path and within the multidimensional pipeline.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 7.

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