Method and system for analyzing dynamic interaction and instability risk between energy storage modules of energy storage power station

Abstract

The invention discloses a dynamic interaction and instability risk analysis method between energy storage modules of an energy storage power station, and the method comprises the steps: firstly building a linearization model of an energy storage integrated system, and recognizing the interconnection relation among the energy storage modules, an AC network and an external power system; a transfer function of an energy storage module is derived under a d-q coordinate system, a closed-loop transfer function model is constructed, a characteristic equation is extracted, and oscillation modes and stability of the energy storage module under different control strategies are analyzed. Research finds that the system stability is influenced by factors such as power amplitude, line parameters and control parameters, and an optimization design scheme is proposed to improve the system stability. In addition, the method also considers the risk of subsynchronous oscillation, and provides a theoretical basis and practical guidance for a safe and efficient energy storage integrated system. The method promotes the application of the energy storage technology in the power system, and enhances the performance and reliability of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems and energy management, and in particular to a method and system for dynamic interaction and instability risk analysis between energy storage modules of a large energy storage power station. Background Art

[0002] In modern power systems, energy storage integrated systems are gradually gaining attention as a key component for balancing the volatility of renewable energy and improving the stability of power systems. However, current research focuses on the stability analysis of converter drivers in renewable energy grid-connected systems, and there is a lack of systematic research on the impact of energy storage integrated systems on stability. In particular, the dynamic behavior and stability of energy storage integrated systems under different control loops have not been deeply explored.

[0003] Existing technologies mainly focus on active power control, and few studies focus on the impact of DC voltage control on the stability of energy storage integrated systems. This leads to a lack of comprehensive evaluation basis when designing and optimizing energy storage integrated systems, making it difficult to achieve optimal power exchange between energy storage systems and power systems.

[0004] In addition, with the increasing application of energy storage integrated systems, the risk of subsynchronous oscillation has gradually emerged. Existing research has failed to fully consider this risk and cannot provide effective response strategies. Therefore, it is particularly important to establish a transfer function model based on energy storage integrated systems to analyze the system stability and its changing laws under different control strategies. Summary of the invention

[0005] In view of the defects of the prior art, the present invention provides a method for analyzing the dynamic interaction and instability risk between energy storage modules of an energy storage power station.

[0006] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0007] A method for analyzing dynamic interaction and instability risk between energy storage modules of an energy storage power station comprises the following steps:

[0008] a) By establishing a linearized model of the energy storage integrated system, the interconnection relationship between the energy storage modules, the AC network and the external power system in the system is identified;

[0009] b) deriving the transfer functions of the constant DC voltage control and the constant active power control of the energy storage module in the dq coordinate system to form a transfer function matrix;

[0010] c) Combine similarity transformation theory to build a closed-loop transfer function model of the energy storage integrated system and define the feedforward link and feedback link;

[0011] d) Extract the characteristic equation of the closed-loop system and analyze the oscillation mode and stability of the energy storage module under different control strategies by solving the characteristic equation;

[0012] e) Evaluate the impact of various influencing factors under different control loops on the stability of the energy storage integrated system, including changes in power amplitude, line parameters and control parameters, and propose targeted optimization design solutions to improve the stability of the energy storage integrated system.

[0013] Furthermore, the step a) of establishing a linearized model of the energy storage integrated system includes:

[0014] Collect the structure and parameter information of the energy storage integrated system, including the number, type and rated power of energy storage modules;

[0015] Describe the dynamic behavior of the system and establish mathematical models of energy storage modules, AC networks and external power systems;

[0016] Determine the interconnection method between modules and draw the system topology diagram;

[0017] The nonlinear model is linearized using the small signal analysis method to obtain the linearized state space equation.

[0018] Furthermore, step b) specifically includes:

[0019] Define the dq coordinate system to convert the AC current and voltage into d-axis and q-axis components.

[0020] The transfer function equations under constant DC voltage control and constant active power control are established respectively, and the formulas are as follows:

[0021] ΔI edk =H dk (s)ΔV edk

[0022] ΔI eqk =H qk (s)ΔV edk

[0023] in,

[0024]

[0025] The dynamic equations of each module are converted into transfer functions to form a transfer function matrix as follows:

[0026]

[0027] Verify the stability of the transfer function to ensure it is valid over the system operating range.

[0028] In the formula, ΔI edk and ΔIeqk : Respectively represent the changes in the d-axis and q-axis currents of the k-th energy storage module.

[0029] ΔV edk : represents the change in the d-axis and q-axis voltages of the k-th energy storage module.

[0030] H dk (s): Transfer function of the kth energy storage module on the d-axis, describing the relationship between input voltage change and output current change.

[0031] H qk(s) : The transfer function of the kth energy storage module on the q-axis, describing the relationship between the input voltage change and the output current change.

[0032] I edk,0 : The d-axis current value of the kth energy storage module in steady state.

[0033] G eidk(s) : The current gain function of the kth energy storage module, which represents the dynamic characteristics related to the current.

[0034] and They represent the proportional control gain and integral control gain of the d-axis respectively.

[0035] C ek : Capacitance value of the kth energy storage module.

[0036] V edck,0 : The d-axis voltage value of the kth energy storage module in steady state.

[0037] V ek,0 : The q-axis voltage value of the kth energy storage module in steady state.

[0038] G idk(s) : The current gain function of the kth energy storage module, describing the dynamic characteristics related to the current.

[0039] I eqk,0 : The q-axis current value of the kth energy storage module in steady state.

[0040] G eiqk(s) : The current gain function of the kth energy storage module, which represents the dynamic characteristics related to the current.

[0041] and They represent the proportional control gain and integral control gain of the q-axis respectively.

[0042] E dqk(s) : Transfer function matrix, describing the dynamic response of each module in the system.

[0043] Furthermore, step c) specifically includes:

[0044] Determine the feedforward and feedback links of the system.

[0045] Applying the similarity transformation theory, the closed-loop system transfer function in the xy coordinate system is derived as follows:

[0046] Z exy Diag(E xyk (s))=Diag(1)

[0047] In the formula, Z exy D: represents the transfer function matrix of the closed-loop system, describing the relationship between the input and output of the system.

[0048] Diag(E xyk (s)): represents a diagonal matrix, the elements of which are the transfer functions E of each energy storage module in the xy coordinate system xyk (s). A diagonal matrix means that each module is independent of each other.

[0049] Diag(1): is a unit diagonal matrix, meaning that all diagonal elements are 1, which means that the system has normal stability or a specific reference state under specific conditions.

[0050] Further, step d) specifically includes:

[0051] Extract the characteristic equation from the closed-loop transfer function and calculate the eigenvalues ​​of the system.

[0052] Analyze the real and imaginary parts of the eigenvalues ​​to determine the oscillation mode and stability of the system.

[0053] For different control strategies (constant DC voltage control and constant active power control), the oscillation modes are solved respectively.

[0054] The oscillation frequency and damping ratio under different conditions are recorded to evaluate their impact on the system stability.

[0055] Further, the step of extracting characteristic equations and analyzing oscillation modes in step d) includes:

[0056] When DC-AC converter DC voltage control is used, the analytical solution is:

[0057]

[0058] In the formula, Z exy The transfer function matrix of the closed-loop system describes the dynamic characteristics of the energy storage integrated system.

[0059] E xy1(s): Transfer function of a single energy storage module in the xy coordinate system, representing the relationship between the input and output of the module.

[0060] I 2×2 : The unit matrix represents the standard state or reference state of the system.

[0061] X eL : Represents the reactance in the system.

[0062] x eL1 : Additional reactance term.

[0063] I e1，0 : Initial current value of a single energy storage module.

[0064] V e1，0 : The initial voltage value of a single energy storage module.

[0065] H d1 (s): Transfer function of a single energy storage module under DC voltage control, describing its dynamic response.

[0066] For a single energy storage module, the characteristic equation is derived as follows:

[0067]

[0068] In the formula, λ e : Represents the characteristic value of the system and reflects the dynamic behavior of the system.

[0069] X m : Indicates a certain inductance or reactance value.

[0070] C e1 : The capacitance value of a single energy storage module affects the dynamic characteristics of the energy storage module.

[0071] V edc1，0 : Initial value of DC voltage control of energy storage module.

[0072] K pp1 : The proportional coefficient of the DC voltage control loop affects the stability of the system.

[0073] K pi1 : The integral coefficient of the DC voltage control loop affects the dynamic response of the system.

[0074] When DC-AC converter active power control is used, the approximate solution is:

[0075]

[0076] Where, X eL : Reactance, which affects the dynamic behavior of the system.

[0077] Kpi1 : The integral coefficient of the active power control loop affects the dynamic response of the system.

[0078] The present invention also discloses a system for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station. The system can be used to implement the above-mentioned method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station, specifically including:

[0079] Linearization model module: establishes a linearization model of the energy storage integrated system and identifies the interconnection between each energy storage module, AC network and external power system;

[0080] Transfer function export module: export the transfer functions of the constant DC voltage control and the constant active power control of the energy storage module in the dq coordinate system, form and manage the transfer function matrix;

[0081] Closed-loop transfer function construction module: Combined with similarity transformation theory, a closed-loop transfer function model of the energy storage integrated system is constructed to define the feedforward link and feedback link;

[0082] Characteristic equation extraction module: extracts the characteristic equation of the closed-loop system and analyzes the oscillation mode and stability of the energy storage module under different control strategies;

[0083] Stability evaluation and optimization module: evaluates the impact of influencing factors under different control loops on system stability, and proposes targeted optimization design solutions to improve the stability of the energy storage integrated system;

[0084] Data analysis and simulation module: collect and analyze system operation data, perform numerical simulation, and verify the effectiveness and feasibility of the optimization plan.

[0085] The present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the above-mentioned method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station is implemented.

[0086] The present invention also discloses a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for analyzing the dynamic interaction and instability risk between energy storage modules of the energy storage power station is implemented.

[0087] Compared with the prior art, the advantages of the present invention are:

[0088] Systematic analysis: By establishing a linearized model, the interconnection between the energy storage module, the AC network and the external power system is systematically identified, which helps to fully understand the dynamic behavior of the system.

[0089] Transfer function optimization: Deriving and analyzing the transfer function matrix can effectively reveal the impact of different control strategies on system performance, making it easier to formulate more accurate control strategies.

[0090] Enhance system stability: By extracting characteristic equations and analyzing oscillation patterns, potential instability risks can be identified, promoting safe operation and stability of the system.

[0091] Flexible response to changing environments: This method can evaluate the influencing factors under different control loops, allowing the system to adapt to diverse operating conditions and improve overall operating efficiency.

[0092] Optimization design guidance: By proposing targeted optimization design solutions, we can provide a scientific basis for the improvement of energy storage integrated systems and enhance the functions and performance of the systems.

[0093] Practicality and verifiability: Combine numerical simulation with theoretical analysis to ensure the effectiveness and feasibility of the optimization solution and improve the reliability and operability of the design. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 It is a schematic diagram of the structure of an energy storage grid-connected system containing N energy storage modules according to an embodiment of the present invention.

[0095] Figure 2 It is a schematic diagram of the closed-loop transfer function structure of the energy storage integrated system according to an embodiment of the present invention.

[0096] Figure 3 It is a flow chart of a method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station according to an embodiment of the present invention. DETAILED DESCRIPTION

[0097] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0098] A method for analyzing dynamic interaction and instability risk between energy storage modules of an energy storage power station, comprising:

[0099] 1. Establishing a linearized model of energy storage integrated system

[0100] like Figure 1 As shown in the figure, it is a model of an energy storage grid-connected system with N energy storage modules, including an energy storage integrated system, an AC network and an external power system. The energy storage integrated system consists of multiple energy storage modules and an internal AC network. Each energy storage includes a DC-DC converter and a DC-AC converter for energy exchange between the power supply and the AC system. The external power system and the energy storage integrated system are interconnected through the AC network. The grid-side converter of the energy storage module adopts constant DC voltage control and constant active power control.

[0101] Since the q-axis control link of constant power control and constant DC voltage control is the same, the q-axis transfer function of constant power control is the same as the q-axis transfer function of constant DC voltage. Combining the above model for theoretical derivation, the transfer function model of the grid-side converter of the kth energy storage module using constant DC voltage control and constant active power control in the dq coordinate system is obtained:

[0102]

[0103] in,

[0104]

[0105] After sorting, it can be written in matrix form:

[0106]

[0107] 2. Stability Analysis Based on Different Control Loop Transfer Functions

[0108] After coordinate transformation, the Figure 2 The closed-loop system shown in FIG. 1 is a closed-loop system with an AC network as a feedforward link and energy storage as a feedback link. Combined with the similarity transformation theory, the closed-loop system transfer function of the energy storage integrated system containing N energy storage modules in the xy coordinate system is derived as follows:

[0109] Z exy Diag(E xyk (s))=Diag(1) (3)

[0110] Where "Diag" means that the matrix is ​​a diagonal matrix.

[0111] When considering a single energy storage module, the following relationship can be obtained from formula (3):

[0112] Z exy E xy1 (s)=I 2×2 (4)

[0113] By calculating the matrix determinant of formula (4), the characteristic equation of a single energy storage module can be obtained as follows:

[0114]

[0115] When DC-AC converter DC voltage control is adopted, equation (5) is solved to obtain the analytical solution of the subsynchronous oscillation mode of a single energy storage module under constant DC voltage control of energy storage:

[0116]

[0117] Similarly, when the DC-AC converter active power control is adopted, the equation (5) is solved and the approximate calculation is:

[0118]

[0119] A simple analysis of the analytical solution of the oscillation mode of a single energy storage module leads to the following conclusions:

[0120] (1) When the power exchange amplitude between energy storage and the power system increases, the stability margin decreases.

[0121] (2) The stability of a single energy storage module decreases with the increase of transmission line reactance and internal line reactance.

[0122] (3) Stability can be improved by increasing the proportional coefficient of the DC voltage control loop and the integral coefficient of the active power control loop respectively.

[0123] (4) The effect of the exchange power on the stability of a single energy storage module is independent of its direction but is determined by its amplitude, which is caused by the transformation between dq and xy coordinates.

[0124] The analysis of the stability of an energy storage integrated system containing multiple energy storage can be regarded as similar to the analysis of an energy storage integrated system containing a single energy storage, realizing similarity transformation. Based on the similarity transformation theory, an energy storage integrated system containing multiple energy storage can be essentially equivalent to an energy storage integrated system with one energy storage and a transmission line with N times the original impedance. Its transfer function is written as:

[0125]

[0126] Find the analytical solution of the oscillation mode:

[0127] 1) Energy storage DC-AC converter adopts constant DC voltage control

[0128]

[0129] Among them, Re(λ e ) is the real part of the variable.

[0130] 2) Energy storage DC-AC converter adopts fixed active power control

[0131]

[0132] It can be seen from equations (9) and (10) that when the number of energy storage modules N increases, the oscillation damping decreases, the oscillation amplitude increases, and the stability of the energy storage integrated system deteriorates.

[0133] 3. Evaluation of the influence of various factors on the damping of oscillation modes

[0134] Since the GFL control of energy storage is based on dq coordinates, while the AC power system operates on xy coordinates. Therefore, when performing GFL control, the AC system power variable must undergo a transformation between dq coordinates and xy coordinates to transform the linear relationship between active power and stability into a nonlinear relationship. Therefore, the phenomenon of "regardless of the power direction, when the power amplitude of the energy storage increases, the stability margin of the energy storage module decreases" is mainly caused by the transformation between dq and xy coordinates.

[0135] However, the effect of the increase in power amplitude on oscillation damping varies with the reactance. Specifically, the larger the reactance value, the more significant the impact on stability for the same increase in power amplitude. eL , the larger the range of oscillation mode trajectory changes. In addition, as x eLk As the value of x increases, the oscillation mode moves to the right of the real axis. eLk With the same power amplitude, the oscillation trajectory of the energy storage integrated system increases.

[0136] In addition, no matter what the direction of the exchange power is, when the energy storage quantity N increases, the oscillation amplitude increases and the waveform becomes less convergent.

[0137] Moreover, the oscillation frequency changes significantly with the change of topology. When the number of branches extending from the transmission line decreases, the oscillation period decreases, and the waveform does not converge when the energy storage power is -1 p.u.

[0138] 4. The main process of the present invention is as follows Figure 3 As shown:

[0139] Step 1: First, based on the configuration of the energy storage integrated system, a closed-loop system transfer function of the energy storage integrated system containing N energy storage modules in the xy coordinate system is constructed, and the oscillation mode between the system under constant DC voltage control and the system under constant active power control is studied.

[0140] Step 2: Extract the characteristic equation based on the system transfer function model, and find the analytical solution of the subsynchronous oscillation mode of the energy storage module under various influencing factors, so as to determine its impact on the system stability.

[0141] Step 3: Based on the above analysis, clarify the impact and impact mechanism of various influencing factors on the system and draw conclusions.

[0142] 5. Examples

[0143] A storage system with 46 nodes, 45 branches and 16 storage modules is used. The full-order model and time-domain simulation are used to analyze the effects of power bidirectionality, line parameters, energy storage quantity and topology on system stability.

[0144] When the number of energy storage devices, line parameters and control parameters are the same and they are connected in parallel, the fewer the number of branches extending from the transmission line, the worse the stability of the energy storage integrated system at the same exchange power.

[0145] For an energy storage integrated system containing multiple energy storage modules, the influence of the bidirectionality of the power flow of the energy storage integrated system on the system stability under different control loops is studied. The main conclusions are as follows:

[0146] 1) When the amplitude of active power exchanged between the energy storage integrated system and the connected power system increases, the stability of the energy storage integrated system will decrease. Specifically, when the DC-AC converter of the energy storage uses constant DC voltage control and experiences significant power exchange, it may cause growing subsynchronous oscillations.

[0147] 2) The stability of the energy storage integrated system is affected by the control loop parameters and line parameters. When the DC-AC converter is controlled at a constant DC voltage, adjusting the proportional coefficient is a more effective option to improve stability. On the other hand, when a constant active power control is used, the integral coefficient is a better choice. When the transmission line is connected to the system, increasing the reactance will directly reduce the stability of the system. Therefore, in order to achieve a higher level of active power exchange between the energy storage and the connected power system, the parameters of the control loop and the network need to be carefully designed.

[0148] In another embodiment of the present invention, a system for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station is provided. The system can be used to implement the above-mentioned method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station, specifically including:

[0149] Linearization model module: establishes a linearization model of the energy storage integrated system and identifies the interconnection between each energy storage module, AC network and external power system;

[0150] Transfer function export module: export the transfer functions of the constant DC voltage control and the constant active power control of the energy storage module in the dq coordinate system, form and manage the transfer function matrix;

[0151] Closed-loop transfer function construction module: Combined with similarity transformation theory, a closed-loop transfer function model of the energy storage integrated system is constructed to define the feedforward link and feedback link;

[0152] Characteristic equation extraction module: extracts the characteristic equation of the closed-loop system and analyzes the oscillation mode and stability of the energy storage module under different control strategies;

[0153] Stability evaluation and optimization module: evaluates the impact of influencing factors under different control loops on system stability, and proposes targeted optimization design solutions to improve the stability of the energy storage integrated system;

[0154] Data analysis and simulation module: collect and analyze system operation data, perform numerical simulation, and verify the effectiveness and feasibility of the optimization plan.

[0155] In another embodiment of the present invention, a terminal device is provided, the terminal device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding functions; the processor described in the embodiment of the present invention can be used for the operation of the dynamic interaction and instability risk analysis method between energy storage modules of energy storage power stations.

[0156] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one disk storage.

[0157] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station in the above embodiment; one or more instructions in the computer-readable storage medium are loaded and executed by the processor.

[0158] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0159] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0160] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0161] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0162] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the implementation methods of the present invention, and should be understood that the protection scope of the present invention is not limited to such special statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station, characterized by: The following steps are involved: a) By establishing a linearized model of the energy storage integrated system, the interconnection relationship between the energy storage modules, the AC network and the external power system in the system is identified; b) deriving the transfer functions of the constant DC voltage control and the constant active power control of the energy storage module in the dq coordinate system to form a transfer function matrix; c) Combine similarity transformation theory to build a closed-loop transfer function model of the energy storage integrated system and define the feedforward link and feedback link; d) Extract the characteristic equation of the closed-loop system and analyze the oscillation mode and stability of the energy storage module under different control strategies by solving the characteristic equation; e) Evaluate the impact of various influencing factors under different control loops on the stability of the energy storage integrated system, including changes in power amplitude, line parameters and control parameters, and propose targeted optimization design solutions to improve the stability of the energy storage integrated system.

2. The method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station according to claim 1, characterized in that: The step a) of establishing a linearized model of the energy storage integrated system comprises: Collect the structure and parameter information of the energy storage integrated system, including the number, type and rated power of energy storage modules; Describe the dynamic behavior of the system and establish mathematical models of energy storage modules, AC networks and external power systems; Determine the interconnection method between modules and draw the system topology diagram; The nonlinear model is linearized using the small signal analysis method to obtain the linearized state space equation.

3. The method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station according to claim 1, characterized in that: Step b) specifically comprises: Define the dq coordinate system to convert the AC current and voltage into d-axis and q-axis components; The transfer function equations under constant DC voltage control and constant active power control are established respectively, and the formulas are as follows: ΔI edk =H dk (s)ΔV edk ΔI eqk =H qk (s)ΔV edk in, The dynamic equations of each module are converted into transfer functions to form a transfer function matrix as follows: Verify the stability of the transfer function to ensure it is valid within the system operating range; In the formula, ΔI edk and ΔI eqk : represent the changes of d-axis and q-axis currents of the k-th energy storage module respectively; ΔV edk : represents the change in the d-axis and q-axis voltages of the k-th energy storage module; H dk (s): transfer function of the kth energy storage module on the d-axis, describing the relationship between input voltage change and output current change; H qk(s) : The transfer function of the kth energy storage module on the q axis, describing the relationship between the input voltage change and the output current change; I edk，0 : d-axis current value of the kth energy storage module in steady state; G eidk(s) : The current gain function of the kth energy storage module, which represents the dynamic characteristics related to the current; and They represent the proportional control gain and integral control gain of the d-axis respectively; C ek : The capacitance value of the kth energy storage module; V edck,0 : d-axis voltage value of the kth energy storage module in steady state; V ek，0 : q-axis voltage value of the kth energy storage module in steady state; G idk(s) : The current gain function of the kth energy storage module, describing the dynamic characteristics related to the current; I eqk,0 : q-axis current value of the kth energy storage module in steady state; G eiqk(s) : The current gain function of the kth energy storage module, which represents the dynamic characteristics related to the current; and They represent the proportional control gain and integral control gain of the q-axis respectively; E dqk(s) : Transfer function matrix, describing the dynamic response of each module in the system.

4. The method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station according to claim 1, characterized in that: Step c) specifically comprises: Determine the feedforward and feedback links of the system; Applying the similarity transformation theory, the closed-loop system transfer function in the xy coordinate system is derived as follows: Z exy Diag(E xyk (s))=Diag(1) In the formula, Z exy D: represents the transfer function matrix of the closed-loop system, which describes the relationship between the input and output of the system and is usually related to the dynamic characteristics and stability analysis of the system; Diag(E xyk (s)): represents a diagonal matrix, the elements of which are the transfer functions E of each energy storage module in the xy coordinate system xyk (s); A diagonal matrix means that each module is independent of each other; Diag(1): is a unit diagonal matrix, meaning that all diagonal elements are 1, which means that the system has normal stability or a specific reference state under specific conditions.

5. The method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station according to claim 1, characterized in that: Step d) specifically comprises: Extract characteristic equation from closed-loop transfer function and calculate eigenvalue of the system; Analyze the real and imaginary parts of the eigenvalues ​​to determine the oscillation mode and stability of the system; For different control strategies (constant DC voltage control and constant active power control), the oscillation modes are solved respectively; The oscillation frequency and damping ratio under different conditions are recorded to evaluate their impact on the system stability.

6. The method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station according to claim 5, characterized in that: The step of extracting characteristic equations and analyzing oscillation modes in step d) comprises: When DC-AC converter DC voltage control is used, the analytical solution is: In the formula, Z exy : The transfer function matrix of the closed-loop system describes the dynamic characteristics of the energy storage integrated system; E xy1 (s): transfer function of a single energy storage module in the xy coordinate system, which represents the relationship between the input and output of the module; I 2×2 : The unit matrix represents the standard state or reference state of the system; X eL : represents the reactance in the system; x eL1 : additional reactance term; I e1，0 : Initial current value of a single energy storage module; V e1，0 : The initial voltage value of a single energy storage module; H d1 (s): transfer function of a single energy storage module under DC voltage control, describing its dynamic response; For a single energy storage module, the characteristic equation is derived as follows: In the formula, λ e : represents the eigenvalue of the system; X m : Indicates a certain inductance or reactance value; C e1 : Capacitance value of a single energy storage module; V edc1，0 : The initial value of the DC voltage control of the energy storage module; K pp1 : Proportional coefficient of DC voltage control loop; K pi1 : Integral coefficient of DC voltage control loop; When DC-AC converter active power control is used, the approximate solution is: Where, X eL : Reactance, which affects the dynamic behavior of the system; K pi1 : The integral coefficient of the active power control loop affects the dynamic response of the system.

7. A dynamic interaction and instability risk analysis system between energy storage modules of an energy storage power station, characterized by: The system can be used to implement the method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station as described in any one of claims 1 to 6, specifically including: Linearization model module: establishes a linearization model of the energy storage integrated system and identifies the interconnection between each energy storage module, AC network and external power system; Transfer function export module: export the transfer functions of the constant DC voltage control and the constant active power control of the energy storage module in the dq coordinate system, form and manage the transfer function matrix; Closed-loop transfer function construction module: Combined with similarity transformation theory, a closed-loop transfer function model of the energy storage integrated system is constructed to define the feedforward link and feedback link; Characteristic equation extraction module: extracts the characteristic equation of the closed-loop system and analyzes the oscillation mode and stability of the energy storage module under different control strategies; Stability evaluation and optimization module: evaluates the impact of influencing factors under different control loops on system stability, and proposes targeted optimization design solutions to improve the stability of the energy storage integrated system; Data analysis and simulation module: collect and analyze system operation data, perform numerical simulation, and verify the effectiveness and feasibility of the optimization plan.

8. A computer device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station as claimed in any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the method for dynamic interaction and instability risk analysis between energy storage modules of an energy storage power station as described in one of claims 1 to 6 is implemented.

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