New energy station transient voltage and frequency coordination stability control method

Abstract

The invention relates to the technical field of power system stability control, in particular to a new energy station transient voltage and frequency coordination stability control method, which comprises the following steps of: analyzing a transient energy evolution rule of an equivalent synchronous motor and stored energy by constructing an alternating current and direct current hybrid dynamic model and fusing with multi-time scale characteristics; based on dynamic weight matrix optimization and a multi-target coordination control strategy, self-adaptive balance of power distribution is realized; a nonlinear feedback algorithm and a real-time compensation mechanism are designed in combination with the Lyapunov theory, and voltage frequency fluctuation in a disturbance scene is suppressed; establishing a multivariable cooperative control architecture, and dynamically adjusting a power adjustment priority and an inertia time constant through coupling iterative optimization of a source storage cooperative strategy to realize adaptive compensation of a transient energy propagation path; according to the method, the dynamic stability and the anti-interference capability of the new energy station under transient impact are remarkably improved, and safe operation of a high-proportion new energy power grid is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of power system stability control, and in particular to a method for coordinated stability control of transient voltage and frequency at a new energy station. Background Art

[0002] Large-scale renewable energy power generation is one of the key development directions for future power systems. However, the rapid development of renewable energy also poses numerous challenges to the safe and stable operation of the system. In recent years, numerous voltage and frequency safety incidents related to renewable energy have occurred. Therefore, given the uncertainty and weak controllability of renewable energy, further research is necessary to study transient frequency and voltage control methods for renewable energy stations.

[0003] Currently, voltage control at renewable energy stations is primarily achieved through two methods: 1. Automatic voltage control systems (AVCs) coordinate and distribute the reactive power output of various reactive sources within the station; 2. Dynamic reactive power compensation devices, such as static VAR compensators (SVCs) and static VAR generators (SVGs), are installed at the sending end to rapidly provide or absorb reactive power, suppress transient overvoltages, and stabilize system voltage.

[0004] Frequency control for renewable energy power plants can be categorized into two main types, voltage source and current source, based on the power output control method. The former primarily utilizes virtual synchronous generator (VSG) technology, introducing the synchronous machine rotor motion equations and electromagnetic transient equations into grid-connected converter control to simulate the synchronous machine's voltage source characteristics to provide primary frequency modulation. The latter primarily utilizes current source inverter control technology, improving the inverter's active power control link and changing the active power output reference value to rapidly respond to system frequency changes. Summary of the Invention

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a method and system for coordinated and stable control of transient voltage and frequency at new energy stations. In order to ensure that the voltage and frequency of stations with a high proportion of new energy access can be controlled within the allowable fluctuation range under transient port energy impact, a coordinated and stable control strategy for transient voltage and frequency at new energy stations considering energy storage is proposed.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a method for coordinated stabilization control of transient voltage and frequency at a new energy station, comprising:

[0009] Build a dynamic model of new energy stations, integrate synchronization characteristics, and analyze evolution laws;

[0010] Based on the equations, coordinate the power allocation and design a first-level coordinated control strategy to optimize the balance between power and energy;

[0011] Apply theoretical design and develop algorithms to achieve stable response under disturbance conditions;

[0012] Establish a coordinated control mechanism to regulate power and maintain energy balance.

[0013] As a preferred solution of the method for coordinated stability control of transient voltage and frequency of a new energy station according to the present invention, a dynamic model of a new energy station is constructed, synchronization characteristics are integrated, and evolution laws are analyzed, including:

[0014] Build a dynamic model that integrates the dynamic characteristics of motors and energy storage;

[0015] Quantify the voltage-frequency coupling characteristics and analyze the evolution laws.

[0016] As a preferred solution of the method for coordinated stability control of transient voltage and frequency of a new energy station according to the present invention, the method includes: coordinating power distribution based on equations, designing a first-level coordinated control strategy, and optimizing the balance of power and energy, including:

[0017] Establish equations, build a collaborative allocation model through synchronization equations, and define optimization goals;

[0018] Design a coordinated control framework and generate a distribution coefficient matrix based on the equations;

[0019] Build a balance optimization mechanism, synchronize equations, and achieve adaptive energy balance.

[0020] As a preferred solution of the method for coordinated stability control of transient voltage and frequency at a new energy station according to the present invention, the first-level coordinated control strategy is designed, including:

[0021] Based on the coordinated control framework, the dynamic model response characteristics are integrated;

[0022] Through synchronization equations, control parameter sets are constructed and dynamic adjustment priorities are defined;

[0023] Establish an adaptive regulation mechanism, analyze parameters in real time through synchronous equations, and optimize and control the dynamic distribution of energy.

[0024] As a preferred solution of the method for coordinated stability control of transient voltage and frequency at a new energy station according to the present invention, the following methods are used to apply theoretical design and develop algorithms to achieve stable response under disturbance conditions:

[0025] Build a control framework based on theory, combine synchronization equations, and design feedback control laws;

[0026] Develop optimization algorithms, fuse equations, generate weight matrices, and achieve dynamic optimization of power allocation;

[0027] A real-time compensation mechanism is established to achieve dynamic balance compensation of disturbance scenarios through synchronous equation solving and dynamic correction coefficients.

[0028] As a preferred solution of the method for coordinated stability control of transient voltage and frequency at a new energy station according to the present invention, the development algorithm includes:

[0029] Develop a multi-timescale optimization algorithm that integrates the equivalent synchronous motor power angle sensitivity model and the energy storage state of charge constraint equation;

[0030] Generate a dynamic weight matrix including virtual inertia compensation to achieve dynamic optimization of power distribution.

[0031] As a preferred solution of the method for coordinated stabilization control of transient voltage and frequency at a new energy station according to the present invention, a coordinated control mechanism is established to perform power regulation and maintain energy balance, including:

[0032] Build a multivariable collaborative control architecture, based on the linkage solution of equations and weight matrices, to achieve dynamic and balanced power distribution among multiple nodes;

[0033] Based on the adaptive regulation mechanism, combined with the synchronization equation, real-time correction coefficient matrix and inertia time constant, the power regulation priority under different disturbance scenarios is optimized;

[0034] A multi-objective energy balance optimization model is established. Through the coupled iterative calculation of the power angle sensitivity parameters of the synchronous units and the energy storage power regulation constraints, the source-storage collaborative control strategy is dynamically adjusted to achieve adaptive compensation and global stability of the transient energy propagation path.

[0035] In a second aspect, the present invention provides a new energy station transient voltage and frequency coordinated stability control system, comprising:

[0036] Dynamic modeling module, builds dynamic models of new energy stations, integrates synchronization characteristics, and analyzes evolution laws;

[0037] Coordinated control module, based on equations, coordinates power allocation, designs a first-level coordinated control strategy, and optimizes the balance between power and energy;

[0038] Stable control module, applying theoretical design and developing algorithms to achieve stable response under disturbance conditions;

[0039] The collaborative regulation module establishes a collaborative control mechanism to perform power regulation and maintain energy balance.

[0040] In a third aspect, the present invention provides an electronic device, comprising:

[0041] memory and processor;

[0042] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for coordinated stability control of transient voltage and frequency of a new energy station are implemented.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for coordinated stability control of transient voltage and frequency of a new energy station.

[0044] Compared with the prior art, the present invention has the following beneficial effects: the present invention improves the ability to accurately characterize the dynamic evolution of transient voltage and frequency in new energy stations by constructing an AC / DC hybrid dynamic model and integrating it with multi-time scale characteristics. On this basis, a multi-objective coordinated control strategy and dynamic weight matrix optimization are designed for actual disturbance scenarios such as short-circuit faults and power mutations that are common in new energy stations. It can achieve rapid response and adaptive energy balance in power distribution, effectively shorten the voltage and frequency recovery time after a fault, and reduce the risk of over-limit. Combining the multivariable collaborative control architecture with the adaptive compensation mechanism of the disturbance scenario, the system's anti-interference ability and global stability are enhanced. For example, when a three-phase short-circuit fault occurs in a new energy station, the coupled iterative optimization of the source-storage collaborative control strategy can quickly suppress the impact of transient energy propagation on the voltage and frequency of the power grid, avoid equipment disconnection due to voltage collapse or frequency anomalies, ensure the safe and stable operation of a high proportion of new energy stations, and reduce power generation losses and maintenance costs caused by fault shutdowns. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 This is an equivalent network diagram of a new energy station according to the method for coordinated stability control of transient voltage and frequency in a new energy station according to an embodiment of the present invention.

[0047] Figure 2 This is a typical source-load curve diagram of a new energy station according to the method for coordinated stability control of transient voltage and frequency in a new energy station according to an embodiment of the present invention.

[0048] Figure 3 This is a power angle curve diagram of the transient voltage and frequency coordinated stability control method for a new energy station according to an embodiment of the present invention.

[0049] Figure 4 This is a transient energy tracking diagram of the transient voltage and frequency coordinated stability control method for a new energy station according to an embodiment of the present invention.

[0050] Figure 5 This is a frequency diagram of node 1 when a three-phase short circuit occurs and the fault is not cut off within a limited time in a method for coordinated stability control of transient voltage and frequency in a new energy station according to an embodiment of the present invention.

[0051] Figure 6 This is a voltage diagram of node 1 when a three-phase short circuit occurs and the fault is not cut off within a limited time in the transient voltage and frequency coordinated stability control method of a new energy station according to an embodiment of the present invention.

[0052] Figure 7 This is a frequency diagram of node 2 when a three-phase short circuit occurs and the fault is not cut off within a limited time in the method for coordinated stability control of transient voltage and frequency in a new energy station according to an embodiment of the present invention.

[0053] Figure 8 This is a voltage diagram of node 2 when a three-phase short circuit occurs and the fault is not cut off within a limited time in the transient voltage and frequency coordinated stability control method of a new energy station according to an embodiment of the present invention.

[0054] Figure 9 This is a power angle characteristic diagram of the transient voltage and frequency coordinated stability control method for a new energy station according to an embodiment of the present invention.

[0055] Figure 10 This is a transient energy diagram of the method for coordinated stability control of transient voltage and frequency at a new energy station according to an embodiment of the present invention.

[0056] Figure 11 This is a frequency diagram of node 1 when a three-phase short circuit fault occurs and is cut off within a limited time in a method for coordinated stability control of transient voltage and frequency at a new energy station according to an embodiment of the present invention.

[0057] Figure 12 This is a voltage diagram of node 1 when a three-phase short circuit fault occurs and is cut off within a limited time in a method for coordinated stability control of transient voltage and frequency in a new energy station according to an embodiment of the present invention.

[0058] Figure 13 This is a frequency diagram of node 2 when a three-phase short circuit fault occurs and is cut off within a limited time in a method for coordinated stability control of transient voltage and frequency at a new energy station according to an embodiment of the present invention.

[0059] Figure 14This is a voltage diagram of node 2 when a three-phase short circuit fault occurs and is cut off within a limited time in the transient voltage and frequency coordinated stability control method of a new energy station according to an embodiment of the present invention. DETAILED DESCRIPTION

[0060] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0061] Example 1, reference Figure 1 , which is an embodiment of the present invention, provides a method for coordinated stability control of transient voltage and frequency at a new energy station, comprising:

[0062] S1: Build a dynamic model of new energy stations, integrate synchronization characteristics, and analyze evolution laws;

[0063] S2: Based on the equations, coordinate the power allocation and design a first-level coordinated control strategy to optimize the balance between power and energy;

[0064] S3: Apply theoretical design and develop algorithms to achieve stable response under disturbance conditions;

[0065] S4: Establish a coordinated control mechanism to adjust power and maintain energy balance.

[0066] It should be noted that the voltage and frequency control of new energy stations in existing technologies mostly adopt a single adjustment method, which fails to fully coordinate the dynamic characteristics of the energy storage system and multiple sources, resulting in insufficient system stability under transient energy shocks and a lack of a fast and adaptive power distribution mechanism, making it difficult to cope with the dynamic balance requirements under complex disturbance scenarios.

[0067] Therefore, in order to address the above-mentioned problems of insufficient coupling of dynamic characteristics, delayed power distribution and weak anti-interference ability, through steps S1-S4, an AC / DC hybrid dynamic model is constructed and the evolution law is analyzed, a multi-objective coordinated control strategy is designed to optimize energy distribution, a nonlinear feedback algorithm is developed to improve the dynamic response speed, and a multi-source collaborative regulation mechanism is established to ensure global energy balance, ultimately achieving rapid stabilization of voltage and frequency and high-reliability operation of new energy stations under transient energy shocks.

[0068] Example 2 is an embodiment of the present invention. Based on the above embodiments, a method for coordinated stability control of transient voltage and frequency at a new energy station is provided.

[0069] In the implementation mode of the present application, a dynamic model of a new energy station is constructed in step S1, and the integrated synchronization characteristics are realized by integrating the AC / DC hybrid dynamic state equations of the equivalent synchronous motor and the energy storage system. The evolution law of the power angle, rotor speed and transient electromotive force is combined to quantify the node voltage-frequency coupling relationship, and a DC damping model is established based on the charging and discharging characteristics of the battery energy storage to analyze the dynamic impact of the transient energy propagation path on the system stability.

[0070] In an optional embodiment, a dynamic model of a new energy station is constructed in step S1. The integrated synchronization characteristics can also be achieved by introducing an electromechanical coupling model of a flywheel energy storage system, combining its rotational inertia and power response characteristics, establishing a multi-energy collaborative inertial support framework, and quantifying the contribution of different energy storage units to the dynamic damping of the synchronous motor power angle.

[0071] In another optional embodiment, a dynamic model of a new energy station is constructed in step S1, and the integrated synchronization characteristics can also be achieved through node voltage frequency sensitivity analysis based on neural network prediction, combined with the fast power compensation characteristics of the superconducting energy storage device, to construct a dynamic adaptive equivalent reactance model, correct the network admittance matrix parameters in real time, and optimize the dynamic matching relationship of AC and DC power interaction in the transient process.

[0072] In the embodiment of the present application, in step S2, based on the equation, power is coordinated and distributed, and a first-level coordinated control strategy is designed by coupling the transient power balance equation with the multi-source dynamic characteristics to model the dynamic weight coefficient matrix, combining the DC damping characteristics of the energy storage system and the equivalent synchronous motor excitation response, and designing a multi-objective optimization control law based on Lyapunov stability theory to achieve rapid coordinated regulation of power distribution and adaptive balance under transient energy shocks.

[0073] In an optional embodiment, in step S2, based on the equation, the power is coordinated and allocated, and a first-level coordinated control strategy is designed. The traditional proportional integral differential (PID) control framework can be introduced, combined with the static power allocation weight coefficient, and a fixed adjustment priority can be set based on historical operating data to achieve steady-state distribution and local balance of multi-source power within the station.

[0074] In another optional embodiment, in step S2, based on the equation, power is coordinated and allocated, and a first-level coordinated control strategy is designed. The fuzzy logic control method can also be used to dynamically adjust the energy storage output ratio according to the fuzzy rule base of the voltage-frequency deviation, and the power adjustment range of each node is limited in combination with the empirical threshold to complete the coarse-grained power allocation in the transient scenario.

[0075] In the embodiment of the present application, step S2 coordinates power allocation based on the equation, designs a first-level coordinated control strategy, optimizes and balances power and energy flow, and further includes:

[0076] Frequency and voltage dynamic model of equivalent synchronous motor:

[0077] The number of nodes in the AC / DC hybrid station is set to m+n. After considering the dynamic process of the DC side of the battery, the state equation of the equivalent synchronous motor of the AC / DC hybrid system considering the excitation characteristics is:

[0078]

[0079] in, are the power angle, rotor angular velocity and transient electromotive force of the equivalent synchronous motor of the new energy station node i during the transient process; is the rated synchronous angular velocity of the new energy station; I di is the direct component of the output current of the equivalent synchronous motor at the new energy station node i; P mi is the input energy of the equivalent synchronous motor at the new energy station node i; E fi is the excitation electromotive force of the equivalent synchronous motor at the new energy station node i; X di and X′ di are the direct equivalent reactance and direct axis transient reactance of the equivalent synchronous motor at the node i of the new energy station; T doi is the transient time constant of the equivalent synchronous motor at the new energy station node i; T ji is the inertia time constant of the equivalent synchronous motor rotor at the new energy station node i; D i Damping coefficient of the equivalent synchronous motor at node i of the new energy station.

[0080] When the battery energy storage is connected to the i-th node of the new energy station, if the battery energy storage system is converting DC power into AC power for input to the grid, that is, the battery energy storage system is in a discharging state, then the active power P of the equivalent synchronous motor in the formula is ei Should be:

[0081] P ei =P aci +P dci +P Li (2)

[0082] Where, P aci and P dci are the AC input power and DC input power of the new energy station node i respectively; P Li is the total equivalent active load power of the new energy station node i.

[0083] When the battery energy storage is connected to the i-th node of the new energy station, if the battery energy storage system is converting AC power into DC power and inputting it into the battery energy storage system, that is, the battery energy storage system is in a charging state, then the active power P of the equivalent synchronous motor in formula (1) is ei Should be:

[0084] P ei =P aci +P dci +P Li (3)

[0085] The first-order inertia chain model is used to describe the DC side dynamic model of the battery energy storage system:

[0086]

[0087] Where, u is the power value given by the DC side of the battery energy storage system when the new energy station is in steady state; dcs is the additional control quantity applied to the DC side of the battery energy storage system during the transient process of the new energy station; T dc is the inertia time constant of the DC side power response of the battery energy storage system during the transient process of the new energy station.

[0088] Assume that the total number of nodes in the new energy station is m + n, of which m are nodes with equivalent synchronous motors, and n are nodes with battery energy storage systems and DC damping control capabilities. Assume that all nodes are load-related, that is, regardless of whether they have equivalent synchronous motors or battery energy storage systems, all nodes are related to equivalent load impedance. After considering the input and output characteristics of the DC side of the battery energy storage system, the power balance equation of the new energy station can be expressed as:

[0089]

[0090] In the implementation mode of the present application, theoretical design is applied in step S3, and an algorithm is developed by integrating Lyapunov stability theory and multi-time scale optimization method, combining the equivalent synchronous motor power angle sensitivity model and energy storage charge state constraint equation, to generate a dynamic weight matrix and a real-time compensation mechanism, so as to realize dynamic optimization and adaptive balance adjustment of power distribution under disturbance scenarios, effectively suppress voltage and frequency fluctuations and maintain synchronous operation of the system.

[0091] in, They are respectively the complex power of the traditional equivalent synchronous motor, the complex power of the battery energy storage system, the complex power of the equivalent load, and the complex power of the new energy equivalent synchronous motor in the transient process of the new energy station; among them, They are respectively the transient electromotive force of the traditional equivalent synchronous motor, the voltage of the battery energy storage system, the equivalent load voltage, and the transient electromotive force of the new energy equivalent synchronous motor in the transient process of the new energy station; among them, They are respectively the current of the traditional equivalent synchronous motor, the current of the battery energy storage system, the equivalent load current, and the current of the new energy equivalent synchronous motor during the transient process of the new energy station; Y is the network conductance matrix of the new energy station during the transient process.

[0092] In an optional embodiment, the theoretical design is applied in step S3, and the algorithm can also be developed by introducing a hybrid framework of fuzzy logic and model predictive control, combining the dynamic response characteristics of the equivalent synchronous motor and the charging and discharging efficiency constraints of the energy storage system, constructing a fuzzy rule base and a rolling optimization strategy, and realizing multi-objective collaborative optimization and dynamic adjustment of power distribution under disturbance scenarios.

[0093] In another optional implementation, the theoretical design is applied in step S3, and the algorithm can also be developed by integrating adaptive sliding mode control and robust optimization methods, combining the dynamic boundary conditions of the energy storage system's state of charge and the equivalent synchronous motor power angle deviation feedback, designing a variable structure control law and a robust weight distribution mechanism, so as to achieve anti-interference regulation and dynamic balance maintenance of power distribution during transient processes.

[0094] In the embodiment of the present application, step S3 applies theoretical design to develop an algorithm to achieve a stable response under disturbance conditions, and further includes:

[0095] From the S2 power balance equation, the total equivalent active power of the equivalent synchronous motor and battery energy storage system connected to node i in the new energy station can be obtained as:

[0096]

[0097] Among them, δ ij =δ i -δ j is the power angle δ of the two equivalent synchronous motors connected at nodes i and j of the new energy station i and δ j The phase angle difference; is the equivalent synchronous motor power angle δ connected at node i i Phase angle of the AC side voltage of the battery energy storage system in the new energy station The phase angle difference between them.

[0098] After considering the DC damping characteristics of battery energy storage, the state equation of the new energy station in the discrete-time system can be expressed as an AC / DC hybrid state equation:

[0099]

[0100] Where x(k) represents the power angle, frequency, transient electromotive force, and DC power of the battery energy storage system at each power node in the new energy station. ξ(k) represents the active and reactive components of the output power of the equivalent synchronous generators of hydropower, thermal power, wind power, and photovoltaic power sources in the new energy station, that is, the direct-axis and quadrature-axis components of the output current of each equivalent synchronous motor. u(k) represents the excitation voltage control variable of the equivalent synchronous generators of hydropower, thermal power, wind power, and photovoltaic power sources, as well as the DC control variable of the battery energy storage system in the new energy station. f represents the relationship function between the complex power, power angle, frequency, transient voltage, and DC power state variables of the equivalent synchronous generators of the battery energy storage system at each power node in the new energy station. G represents the relationship function between the system controllable input variables and the station state variables, where the state variables include the equivalent synchronous complex power, power angle, frequency, transient voltage, and DC power of the battery energy storage system at each power node in the transmission system. β represents the complex power balance equation of the station.

[0101] Assume that the equivalent synchronous motors in the new energy station are nodes 1, 2, ..., m, and the battery energy storage system is nodes m+1, m+2, ..., m+n. The relationship function of the equivalent synchronous generator complex power, power angle, frequency, transient voltage, and DC power state variables of the battery energy storage system at each power node in the new energy station is shown in the formula; it is determined by the AC / DC hybrid state equation:

[0102]

[0103] According to the AC / DC hybrid state equation, the relationship function between the system controllable input variables and the station state variables is as follows:

[0104]

[0105] The complex power balance equation of the new energy station is:

[0106] β(x,ξ)=[β1(x,ξ)…β i (x,ξ)…β m+k-p (x,ξ)] T (10)

[0107] in:

[0108]

[0109] In the embodiment of the present application, a coordinated control mechanism is established in step S4 to perform power regulation and maintain energy balance, including:

[0110] According to the frequency and voltage trajectory evolution characteristics of each equivalent power node, the equivalent power voltage and frequency of each node in the new energy station are controlled.

[0111] Transient stability balance point of new energy station (xe ,y e ) is defined as:

[0112]

[0113] When the new energy station is in steady state The corresponding steady-state input control quantity is u r .

[0114] When the new energy station is in a transient process, the deviation equation of the state equation under the state evolution trajectory is:

[0115]

[0116] in, Δu=uu r , Δf=f(x,y)-f(x e ,y e ), and Δρ=ρ(x,y)-ρ(x e ,y e ).

[0117] The voltage and frequency output functions of the new energy station corresponding to the dynamic system are:

[0118] g=h(x,y) (14)

[0119] Under the transient stability conditions of the new energy station, the frequency and voltage control target deviations ξ that need to be controlled and constrained during the transient process are:

[0120] ξ=Δg=gg r (15)

[0121] Where g r Indicates the evolution trajectory of the frequency and voltage output functions of each equivalent power node when the new energy station is in a transient stable equilibrium state

[0122] From the above analysis, it can be seen that the frequency and voltage control target deviation ξ in the transient process of the new energy station is independent of the stable equilibrium state of the system and its corresponding state variables. It can be concluded that:

[0123]

[0124] Based on the above two equations, this patent constructs a multi-objective dynamic control system for the frequency and voltage of the equivalent synchronous motors at the power generation network nodes under the transient stability of new energy stations:

[0125]

[0126] Where u is the control input of the equivalent synchronous motor active power and excitation voltage at each node, and is the DC side power control input of the battery energy storage system. The coefficient matrices A and B are as follows:

[0127]

[0128] Diagonal matrix A i and B i In Brunovsky standard form:

[0129]

[0130] Among them, μ i is the subsystem dimension of the i-th input of the multi-objective dynamic control system.

[0131] According to Lyapunov theory, the feedback control law of the linear system is designed:

[0132] u=-Kξ (20)

[0133] In the formula, ξ=(A-BK)ξ, (A-BK) and Re(λi[A-BK])<0. K=R -1 B T P is the control matrix. R is the positive definite weight matrix, and P is the Riccati equation PA+A T P-PBR -1 B T Solution of P = -Q, where Q is a positive definite matrix.

[0134] Therefore, the linear control law of the i-th subsystem designed to stabilize the system can be expressed as:

[0135]

[0136] Then, solve the nonlinear equivalent input u i , if the algebraic variable in the algebraic equation is an explicit function, then the algebraic variable is derived. If the algebraic variable in the algebraic equation is an implicit function, the calculation is as follows:

[0137]

[0138] Among them, Λ(x,y) is the relationship transformation matrix, I n is an n×n identity matrix, and the linear input μ is obtained i The corresponding equivalent nonlinear control input is:

[0139]

[0140] in,

[0141] Excitation control model of equivalent synchronous motor in new energy station:

[0142] When the system is subject to large disturbances, excitation control can maintain the stability of the system voltage and frequency. The system's power balance and rotor power angle are key to determining the stability of the system frequency and voltage. Therefore, the generator's angular frequency, active power, and terminal voltage are selected as output functions, and the target deviation can be expressed as:

[0143]

[0144] The multi-objective equation is constructed based on the target deviation. The multi-objective sub-equation of the generator excitation control corresponding to the i-th subsystem is:

[0145]

[0146] Design a linear feedback control law to stabilize the system:

[0147]

[0148] The target deviation is obtained The Γ derivative of :

[0149]

[0150] The equivalent additional excitation control input is:

[0151]

[0152] For systems without wide-area signal acquisition, the control signal can be controlled using local conventional acquisition signals as follows:

[0153]

[0154] Nonlinear additional control model of battery energy storage system:

[0155] The nonlinear additional control of battery energy storage can suppress the power fluctuation of the power grid, increase the system damping, and improve the transient stability of the system through the rapid power control of the DC system. Therefore, the control target deviation is determined as the deviation Δω between the actual operation and stable operation of the system frequency and the AC tie line power deviation ΔP ac , DC power generation deviation ΔP dc The deviation power relationship obtained by replacing the constant load with the impedance equivalent is:

[0156] ΔP cni =ΔP ti -ΔP dni (32)

[0157] The target equation based on the target deviation is:

[0158]

[0159] According to the control algorithm proposed in this patent, the DC linear control law is:

[0160]

[0161] in, Designed according to the Lyapunov method.

[0162] According to the above equation, the DC nonlinear additional control of battery energy storage can be obtained as:

[0163]

[0164] In summary, the present invention achieves precise regulation of transient voltage and frequency and dynamic energy balance of new energy stations by constructing an AC / DC hybrid dynamic model and a multi-source collaborative control strategy, integrating the dynamic characteristics of the equivalent synchronous motor and the rapid response advantages of the energy storage system, and combining a nonlinear feedback algorithm with an adaptive compensation mechanism. It significantly improves the system's anti-interference ability and global stability, and provides reliable protection for the safe and stable operation of a high proportion of new energy access to the power grid.

[0165] Example 3, reference Figures 1-14 , is an embodiment of the invention, which provides a dual-high-characteristic power transient stability analysis method. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0166] The topological structure of the equivalent network model of new energy stations is as follows: Figure 1 The typical source load curve of the station is shown as follows: Figure 2 As shown. Figure 1 Taking the three-phase short-circuit fault of node 2 as an example, the effectiveness of the transient energy balance robust control model of the power generation system established by this patent is verified.

[0167] The total load of the new energy station at node 2 is 12,000 MW, with an AC transmission power of 2,300 MW and a DC transmission power of 2,800 MW. The total load of the receiving system at node 1 is 15,200 MW, with 3,000 MW of DC power received from the station. The total load of the receiving system at node 3 is 50,000 MW, with 2,000 MW of AC power received from the station. In the new energy station shown in Figure S, PV1 and PV2 are photovoltaic power generation nodes, WP1 and WP2 are wind power nodes, HG1 is a hydropower generation node, G1 and G2 are thermal power generation nodes, and ES1, ES2, ES3, and ES4 are energy storage system nodes.

[0168] When a three-phase short circuit occurs at node 2 of the new energy station and the fault is not cut off within the specified time, the equivalent power angle instability curve of node 2 and its corresponding transient port energy tracking are as follows: Figure 3-4 shown.

[0169] like Figure 3 As shown in the figure, when a three-phase short circuit occurs at station node 2 and the fault is not cleared within the specified time, the system acquires a large amount of transient energy. Comparing the proposed transient energy balance robust control model with an unestablished system power angle variation characteristic reveals the following: Although the system is equipped with battery energy storage, without an effective energy tracking control algorithm, the rapid energy balance characteristics of the station battery energy storage cannot be fully utilized, and the system will remain unstable. With energy balance control, the system maintains excellent stability and can quickly bring the power angle back to synchronization with the two pendulums.

[0170] At the same time, if Figure 3 As shown in Figure 1, the energy tracking control algorithm proposed in this patent can quickly determine the port energy obtained by the station when a transient fault is triggered. The port energy response is achieved through the effective coordination of energy storage and other power sources in the new energy station.

[0171] When a three-phase short circuit occurs at station node 2 and the fault is not cut off within the specified time, the frequency and voltage change curves of the equivalent synchronous motors at station nodes 1 and 2 are as follows: Figure 5-8 shown.

[0172] like Figure 4 As shown in the figure, when a three-phase short circuit occurs at the outlet of the new energy station channel and the fault is not cut off within the specified time, due to the large transient energy imbalance of the system and the rapid propagation within the system, the frequency and voltage of the equivalent synchronous motors at grid nodes 1 and 2 are significantly affected. However, under the action of the voltage-frequency control algorithm proposed in this patent, the voltage and frequency exceedance time is short and the impact on the system is small. On the contrary, if the frequency-voltage multi-objective nonlinear control model proposed in this patent is not adopted, the frequency and voltage of the grid-connected power supplies at nodes 1 and 2 will have a large deviation. The transient energy obtained by the system is large.

[0173] When a three-phase short circuit occurs at station node 2 and the fault is cut off within the limited cut-off time, the equivalent power angle instability curve of station node 2 and its corresponding transient port energy tracking are as follows: Figure 9-10 shown.

[0174] like Figure 5 As shown in the figure, when a three-phase short circuit occurs at station node 2 and the fault is cleared within a limited time, the system receives relatively little transient energy. By comparing the power angle variation characteristics of the system before and after the proposed transient energy balance robust control model is implemented, the following conclusions are drawn: An effective energy tracking control algorithm can better utilize the rapid energy regulation characteristics of battery energy storage. This effectively reduces the fluctuation amplitude of the station and restores synchronization within a relatively short period of time.

[0175] When a three-phase short circuit occurs at station node 2 and the fault is cut off within a limited time, the frequency and voltage change curves of the equivalent synchronous motors at station nodes 1 and 2 are as follows: Figure 11-14 shown.

[0176] like Figure 6 As shown in the figure, when a three-phase short circuit occurs at node 2 of the new energy station and the fault is disconnected within a limited time, the transient energy imbalance in the system is small, and the propagation of transient energy in the system has little impact on the frequency and voltage of the equivalent synchronous motors at nodes 1 and 2. At the same time, this voltage-frequency control algorithm can significantly reduce the amplitude of voltage and frequency fluctuations, achieving rapid suppression of voltage and frequency fluctuations.

[0177] Example 4. The above is a schematic scheme of a method for coordinated and stable control of transient voltage and frequency at a new energy station. It should be noted that the technical scheme of the system for coordinated and stable control of transient voltage and frequency at a new energy station is based on the same concept as the technical scheme of the method for coordinated and stable control of transient voltage and frequency at a new energy station described above. For details not described in detail in the technical scheme of the system for coordinated and stable control of transient voltage and frequency at a new energy station in this embodiment, please refer to the description of the technical scheme of the method for coordinated and stable control of transient voltage and frequency at a new energy station described above.

[0178] This embodiment also provides a new energy station transient voltage and frequency coordinated stability control system, including:

[0179] Dynamic modeling module, builds dynamic models of new energy stations, integrates synchronization characteristics, and analyzes evolution laws;

[0180] Coordinated control module, based on equations, coordinates power allocation, designs a first-level coordinated control strategy, and optimizes the balance between power and energy;

[0181] Stable control module, applying theoretical design and developing algorithms to achieve stable response under disturbance conditions;

[0182] The collaborative regulation module establishes a collaborative control mechanism to perform power regulation and maintain energy balance.

[0183] This embodiment also provides an electronic device suitable for the coordinated stability control of transient voltage and frequency at a new energy station, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the method for coordinated stability control of transient voltage and frequency at a new energy station proposed in the above embodiment.

[0184] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for realizing coordinated stability control of transient voltage and frequency of a new energy station as proposed in the above embodiment is implemented.

[0185] The storage medium proposed in this embodiment and the method for realizing coordinated stability control of transient voltage and frequency of new energy stations proposed in the above embodiment belong to the same inventive concept. Technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0186] Through the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented with the help of software and necessary general hardware, and of course can also be implemented by hardware. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention.

[0187] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for coordinated stability control of transient voltage and frequency at a new energy station, characterized in that: include: Build a dynamic model of new energy stations, integrate synchronization characteristics, and analyze evolution laws; Based on the equations, coordinate the power allocation and design a first-level coordinated control strategy to optimize the balance between power and energy; Apply theoretical design and develop algorithms to achieve stable response under disturbance conditions; Establish a coordinated control mechanism to regulate power and maintain energy balance.

2. The method for coordinated stability control of transient voltage and frequency at a new energy station according to claim 1, characterized in that: Build a dynamic model of new energy stations, integrate synchronization characteristics, and analyze evolution laws, including: Build a dynamic model that integrates the dynamic characteristics of motors and energy storage; Quantify the voltage-frequency coupling characteristics and analyze the evolution laws.

3. The method for coordinated stability control of transient voltage and frequency at a new energy station according to claim 2, characterized in that: Based on the equations, coordinate power allocation and design a first-level coordinated control strategy to optimize the balance of power and energy, including: Establish equations, build a collaborative allocation model through synchronization equations, and define optimization goals; Design a coordinated control framework and generate a distribution coefficient matrix based on the equations; Build a balance optimization mechanism, synchronize equations, and achieve adaptive energy balance.

4. The method for coordinated stability control of transient voltage and frequency at a new energy station according to claim 3, characterized in that: The first-level coordinated control strategy is designed, including: Based on the coordinated control framework, the dynamic model response characteristics are integrated; Through synchronization equations, control parameter sets are constructed and dynamic adjustment priorities are defined; Establish an adaptive regulation mechanism, analyze parameters in real time through synchronous equations, and optimize and control the dynamic distribution of energy.

5. The method for coordinated stability control of transient voltage and frequency at a new energy station according to claim 4, characterized in that: Apply theoretical design and develop algorithms to achieve stable response under disturbance conditions, including: Build a control framework based on theory, combine synchronization equations, and design feedback control laws; Develop optimization algorithms, fuse equations, generate weight matrices, and achieve dynamic optimization of power allocation; A real-time compensation mechanism is established to achieve dynamic balance compensation of disturbance scenarios through synchronous equation solving and dynamic correction coefficients.

6. The method for coordinated stability control of transient voltage and frequency at a new energy station according to claim 5, characterized in that: The development algorithm includes: Develop a multi-timescale optimization algorithm that integrates the equivalent synchronous motor power angle sensitivity model and the energy storage state of charge constraint equation; Generate a dynamic weight matrix including virtual inertia compensation to achieve dynamic optimization of power distribution.

7. The method for coordinated stability control of transient voltage and frequency at a new energy station according to claim 6, characterized in that: Establish a coordinated control mechanism to regulate power and maintain energy balance, including: Build a multivariable collaborative control architecture, based on the linkage solution of equations and weight matrices, to achieve dynamic and balanced power distribution among multiple nodes; Based on the adaptive regulation mechanism, combined with the synchronization equation, real-time correction coefficient matrix and inertia time constant, the power regulation priority under different disturbance scenarios is optimized; A multi-objective energy balance optimization model is established. Through the coupled iterative calculation of the power angle sensitivity parameters of the synchronous units and the energy storage power regulation constraints, the source-storage collaborative control strategy is dynamically adjusted to achieve adaptive compensation and global stability of the transient energy propagation path.

8. A coordinated stability control system for transient voltage and frequency at a new energy station, applying the method according to any one of claims 1 to 7, characterized in that: include: Dynamic modeling module, builds dynamic models of new energy stations, integrates synchronization characteristics, and analyzes evolution laws; Coordinated control module, based on equations, coordinates power allocation, designs a first-level coordinated control strategy, and optimizes the balance between power and energy; Stable control module, applying theoretical design and developing algorithms to achieve stable response under disturbance conditions; The collaborative regulation module establishes a collaborative control mechanism to perform power regulation and maintain energy balance.

9. An electronic device comprising: memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the transient voltage and frequency coordinated stability control method of the new energy station described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for coordinated stability control of transient voltage and frequency at a new energy station as described in any one of claims 1 to 7.

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