Electrochemical energy storage power station oscillation risk test method and device covering multiple working conditions

Abstract

The application discloses an oscillation risk test method and device for an electrochemical energy storage power station covering multiple working conditions, and relates to the technical field of power system automation. The method comprises the following steps: injecting a harmonic voltage into a test device comprising a semi-physical simulation platform, collecting a wide-frequency impedance curve of the electrochemical energy storage power station, and extracting a stability margin index from the wide-frequency impedance curve. When the index does not meet a preset threshold, it is determined that the electrochemical energy storage power station has a wide-frequency oscillation risk. The application provides an oscillation risk test method and device for an electrochemical energy storage power station covering multiple working conditions. A semi-physical simulation platform is built based on a double-access mode, a harmonic voltage is injected into the platform to collect a wide-frequency impedance curve, a stability margin index is obtained according to the curve, and a quantitative determination is made by comparing the index with a preset threshold. The method can solve the problems that the existing oscillation risk test method for an electrochemical energy storage power station cannot fully adapt to multiple working conditions and cannot accurately and quantitatively determine the wide-frequency oscillation safety risk of the power station.

Description

Technical Field

[0001] This application relates to the field of power system automation technology, and in particular to a method, device, medium and product for testing the oscillation risk of electrochemical energy storage power stations covering multiple operating conditions. Background Technology

[0002] With the global push for clean energy development and the continuous expansion of new energy power generation such as photovoltaics and wind power, the output of these technologies is intermittent and fluctuating. Electrochemical energy storage power stations are therefore widely used to mitigate power fluctuations and ensure stable power system operation. However, as the scale of energy storage power stations continues to expand and application scenarios become increasingly complex, the multi-condition operation characteristics of these stations and their internal power electronic equipment are prone to causing broadband oscillations, posing a serious threat to the safety and stability of both the energy storage power station and the entire power grid. Existing oscillation risk testing for electrochemical energy storage power stations mainly includes three technical solutions: first, building mathematical models of batteries, converters, and power networks to conduct theoretical analysis and simulation calculations; second, collecting electrical quantity data such as voltage and current at the power station site for steady-state and transient tests; and third, injecting specific frequency signals into the AC / DC sides of the power station and analyzing and assessing the oscillation risk based on the system response.

[0003] However, theoretical analysis and simulation calculations suffer from large deviations from reality due to insufficient model accuracy and difficulty in obtaining parameters; field testing is limited by actual operating conditions and cannot fully cover a variety of complex operating conditions; signal injection testing is only for specific frequencies and operating conditions, and some solutions can only qualitatively determine whether there is oscillation, but cannot quantify stability margin, thus failing to fully adapt to multiple operating conditions and accurately quantify risks. Summary of the Invention

[0004] This application provides a method and apparatus for testing the oscillation risk of electrochemical energy storage power stations covering multiple operating conditions, in order to solve the problem that existing oscillation risk testing methods for electrochemical energy storage power stations cannot fully adapt to multiple operating conditions and are difficult to accurately and quantitatively determine the broadband oscillation safety risks of power stations.

[0005] To achieve the above objectives, this application provides a method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, including: By injecting harmonic voltage into a test device containing a hardware-in-the-loop simulation platform, the broadband impedance curve of the electrochemical energy storage power station is acquired. The hardware-in-the-loop simulation platform is based on a dual-access mode, which is built by directly connecting a real-time simulator to the energy storage controller of the electrochemical energy storage power station via a digital-to-analog converter, or by connecting to a black-box model that encapsulates the corresponding control program of the electrochemical energy storage power station. The stability margin index is obtained based on the wideband impedance curve. If the stability margin index does not meet the preset threshold, the electrochemical energy storage power station is determined to have a wideband oscillation risk.

[0006] This application employs a dual-access mode in platform construction. It can directly connect to the energy storage controller via a real-time simulator and digital-to-analog converter to recreate the control logic and hardware interaction scenarios of the actual power station operation. Simultaneously, it can access a black-box model encapsulating the control program, adapting to the control modes of energy storage power stations from different manufacturers and with different specifications. This breaks the limitations of existing single-access testing platforms, flexibly simulating various operating conditions such as power station startup, grid connection, load fluctuations, and fault recovery, enabling risk testing under multiple operating conditions and solving the pain point of existing methods' inability to fully adapt to multiple operating conditions. In the data acquisition stage, by injecting harmonic voltage into the testing device containing the hardware-in-the-loop simulation platform, it can accurately capture the broadband impedance curves of the electrochemical energy storage power station at different frequencies. Impedance characteristics are a core indicator reflecting the oscillation risk of the power station. Broadband coverage can fully present the response characteristics of the power station in different frequency ranges, avoiding the risk omissions caused by existing tests only targeting specific frequencies and incomplete data acquisition. In terms of risk assessment, stability margin indicators are extracted based on broadband impedance curves and quantitatively judged through preset thresholds. This replaces the shortcomings of existing methods that rely heavily on qualitative analysis and lack unified quantitative standards. It can accurately quantify the safety risk level of broadband oscillations in power plants and clearly determine whether there are potential oscillation hazards in power plants. This achieves accurate quantitative assessment of broadband oscillation risks and effectively solves the problem that existing tests are difficult to accurately quantify risks.

[0007] Compared to existing technologies, this application builds a hardware-in-the-loop (HIL) simulation platform through a dual-access mode, which can flexibly adapt to various operating conditions of electrochemical energy storage power stations. By injecting harmonic voltage into the test device containing the HIL simulation platform, it accurately collects broadband impedance curves, and then obtains stability margin indicators based on these curves and performs quantitative judgments in combination with preset thresholds. This enables accurate identification of broadband oscillation safety risks in power stations, thus solving the problem that existing electrochemical energy storage power station oscillation risk testing cannot fully adapt to multiple operating conditions and is difficult to accurately and quantitatively identify broadband oscillation safety risks in power stations.

[0008] As a preferred approach, the broadband impedance curve of the electrochemical energy storage power station is acquired by injecting harmonic voltage into a test device containing a hardware-in-the-loop simulation platform, specifically as follows: Under preset typical operating conditions, harmonic voltage is injected into the test device containing the hardware-in-the-loop simulation platform, and the harmonic current corresponding to the full frequency points is measured simultaneously. Based on the phasor ratio calculation of the harmonic voltage and harmonic current of the same order, the order impedance of the corresponding order is obtained. Based on the sequence impedance at all frequency points, a broadband impedance curve for the electrochemical energy storage power station is generated by fitting.

[0009] This preferred solution obtains the sequence impedance based on the phasor ratio of harmonic voltage and current of the same order, accurately reflecting the impedance characteristics of energy storage power stations at different frequencies. This solves the problems of inaccurate impedance calculation and lack of specificity in traditional testing methods. By fitting the sequence impedance at all frequencies to generate a broadband impedance curve, the impedance variation law of the energy storage power station over a wide frequency range can be intuitively presented. This provides reliable and comprehensive data support for obtaining subsequent stability margin indicators, significantly improving the scientificity and accuracy of broadband oscillation risk testing, providing a solid foundation for risk assessment, and effectively avoiding risk misjudgment caused by incomplete data.

[0010] As a preferred option, the preset typical operating conditions include the full operating conditions of the energy storage converter, the full reactive power operating conditions of the SVG, and the grid operation conditions. Specifically, the active power output levels of the energy storage converter are divided and adjusted according to the charging and discharging modes, and the adjustment results are processed by different preset reactive power types and power factors to construct the full operating conditions of the energy storage converter. Based on the rated reactive power of the SVG, the reactive power output is divided and adjusted to construct the full reactive power operating condition of the SVG, which covers the entire operating range of the SVG reactive power adjustment. By configuring preset normal operating modes and line fault types for the power grid, corresponding normal and fault scenarios are set to construct the power grid operating conditions, which cover various normal and fault scenarios. Based on actual testing requirements, the full operating conditions of the energy storage converter, the full reactive power condition of the SVG, and the grid operation condition are arbitrarily arranged and combined to obtain a complete set of test conditions covering all operating scenarios of the electrochemical energy storage power station; the complete test conditions are the operating scenarios of the electrochemical energy storage power station when the broadband impedance curve is collected.

[0011] This optimized solution clearly defines the specific types and coverage of preset typical operating conditions, overcoming the shortcomings of traditional test conditions that are singular and incomplete, ensuring that test results are adaptable to various scenarios in the actual operation of energy storage power stations. The comprehensive coverage of all operating conditions for the energy storage converter, all reactive power conditions for the SVG, and grid operation conditions can fully capture the broadband characteristics of energy storage power stations under different operating states, avoiding the undetected potential oscillation risks due to omitted operating conditions. Furthermore, the implementation methods of each operating condition are closely aligned with actual operation and maintenance scenarios. For example, the energy storage converter adjusts its active power output level, reactive power type, and power factor; the SVG adjusts its reactive power output level; and the grid operation conditions are configured with conventional operating modes and line fault types. This makes the test conditions more practical and targeted, realistically simulating the complex operating conditions in actual power station operation, improving the comprehensiveness and practicality of risk testing, and providing more comprehensive protection for the safe and stable operation of the power station.

[0012] As a preferred approach, the active power output levels of the energy storage converter are divided and adjusted according to its charging and discharging modes. The adjustment results are then processed using different preset reactive power types and power factors to construct the full operating condition of the energy storage converter. Specifically: For the charging and discharging modes of the energy storage converter, the active power output is divided into several levels according to the target rated power in each mode and then adjusted to obtain the active power output data of each level. Based on the active power output data for each level, the maximum capacitive reactive power, power factor, and maximum inductive reactive power under the corresponding active power output are matched respectively, and combined to form the full operating conditions of the energy storage converter.

[0013] This optimized solution matches the maximum capacitive reactive power, power factor, and maximum inductive reactive power for each active power output level, achieving precise matching of active and reactive power. It realistically simulates the operating state of the energy storage converter under different loads and reactive power configurations, solving the problems of unreasonable active and reactive power matching and disconnect from actual operating scenarios in traditional operating condition settings. This refined operating condition configuration can accurately capture the broadband oscillation characteristics of the energy storage power station under different combinations of operating parameters, improving the targeting and accuracy of testing. It can effectively identify potential oscillation risks under specific operating conditions, providing precise data support for parameter optimization and risk control of the energy storage converter.

[0014] As a preferred embodiment, the stability margin index is obtained based on the broadband impedance curve, specifically as follows: For the aforementioned broadband impedance curve, at the phase critical frequency point, the amplitude margin is calculated by combining the ratio of the impedance amplitude on the power station side to the impedance amplitude on the grid side. At the critical frequency point of amplitude, the phase margin is calculated by combining the phase of the power station side impedance and the phase margin of the grid side impedance. The stability margin index is composed of the magnitude margin and the phase margin.

[0015] This preferred solution, through the combined use of amplitude margin and phase margin, comprehensively reflects the broadband stability characteristics of energy storage power stations. These two indicators complement and corroborate each other, avoiding the limitations of relying on a single indicator and ensuring a more scientific and comprehensive assessment of broadband oscillation risks. This quantitative stability margin indicator not only accurately determines whether an oscillation risk exists but also intuitively reflects the severity of the risk, providing a clear quantitative basis for the formulation of subsequent risk control measures. This facilitates operation and maintenance personnel in optimizing equipment parameters in a targeted manner, mitigating oscillation risks, and improving the stability of power station operation.

[0016] As a preferred embodiment, if the stability margin index does not meet the preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk, specifically: If either the amplitude margin or the phase margin fails to meet the corresponding preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk.

[0017] In this preferred scheme, amplitude margin and phase margin are core indicators reflecting the broadband stability characteristics of a power station. Failure of either margin to meet the standard indicates a potential oscillation hazard. This judgment logic can promptly identify the risks arising from a single indicator exceeding the standard, solving the problem of delayed risk identification caused by the traditional approach of "only determining risk when both indicators fail to meet the standard." Simultaneously, the clear judgment logic provides testing personnel with clear operational standards, reducing errors in human judgment, improving the consistency and accuracy of risk assessment, and facilitating timely detection of potential hazards and implementation of preventative measures by maintenance personnel. This effectively reduces the probability of broadband oscillation accidents and ensures the safe and stable operation of the energy storage power station.

[0018] As a preferred embodiment, the hardware-in-the-loop simulation platform is integrated with a single energy storage converter AC port, an SVG AC port, and an energy storage power station grid connection point as measurement points; The AC port of a single energy storage converter is formed by configuring a dedicated measurement point on the topology node of the AC output side of the single energy storage converter in the real-time simulator. The SVG AC port is formed by configuring a dedicated measurement point on the AC grid-connected topology node of the static var generator in the real-time simulator. The grid connection point of the energy storage power station is formed by converging the AC output branches of all equipment on the power station side to a common connection point and configuring a total measurement point.

[0019] This preferred solution integrates the AC ports of a single energy storage converter, the AC ports of an SVG (Induction Var Generator), and the grid connection point of the energy storage power station, enabling comprehensive testing of both individual devices and the entire power station. This solves the problem of traditional platforms having limited test points and failing to cover both local and overall aspects. The configuration of dedicated measurement points, such as dedicated points on the AC output side of the single energy storage converter and the AC grid connection side of the SVG, ensures the accuracy of data acquisition and avoids data distortion caused by unreasonable measurement points. The grid connection point of the energy storage power station forms a common connection point through a busbar and is configured with a total measurement point, comprehensively reflecting the broadband characteristics of the entire power station. This approach balances local testing of individual devices with system-wide testing of the entire power station, improving the comprehensiveness and flexibility of the testing. This port configuration makes the hardware-in-the-loop (HIL) simulation platform more closely match actual testing needs, providing reliable hardware support for multi-condition, multi-dimensional broadband oscillation risk testing, and improving testing efficiency and data accuracy.

[0020] As a preferred embodiment, the harmonic voltage is a positive-sequence harmonic voltage or a negative-sequence harmonic voltage that does not exceed a first threshold.

[0021] This preferred solution specifies the exact parameters of harmonic voltage, limiting it to no more than 0.1 per unit. This ensures effective acquisition of harmonic signals to meet testing requirements while preventing excessively high harmonic voltages from impacting energy storage power station equipment and the hardware-in-the-loop simulation platform, thus protecting equipment safety. It also solves the problem of equipment damage or data distortion caused by unreasonable harmonic voltage amplitudes in traditional testing. The reasonable harmonic voltage parameter settings balance testing effectiveness, equipment safety, and test realism, standardize the testing process, ensure the comparability of test results under different testing scenarios, improve the standardization and universality of broadband oscillation risk testing, and adapt to the testing needs of different types of electrochemical energy storage power stations.

[0022] This application also provides an electrochemical energy storage power station oscillation risk testing device covering multiple operating conditions, including an impedance acquisition module and a risk assessment module; The impedance acquisition module is used to acquire the broadband impedance curve of the electrochemical energy storage power station by injecting harmonic voltage into the test device containing the hardware-in-the-loop simulation platform. The hardware-in-the-loop simulation platform is built based on a dual-access mode, which is a real-time simulator connected directly to the energy storage controller of the electrochemical energy storage power station via a digital-to-analog converter, or connected to a black box model that encapsulates the corresponding control program of the electrochemical energy storage power station. The risk assessment module is used to obtain a stability margin index based on the broadband impedance curve. If the stability margin index does not meet a preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk.

[0023] This application also provides a storage medium storing a computer program, which is called and executed by a computer to implement the above-described method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions.

[0024] This application also provides a computer program product, including a computer program or instructions, which, when executed by a communication device, implements the above-described method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating a method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, provided in an embodiment of this application. Figure 2 This is a system architecture diagram provided in the embodiments of this application; Figure 3 This is a diagram showing the composition of the simulation model provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of an electrochemical energy storage power station oscillation risk testing device covering multiple operating conditions provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] In the description of this application, unless otherwise stated, "a number" means two or more.

[0028] The present application provides a method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions. This method aims to address the problems of insufficient theoretical modeling accuracy, high cost and risk of on-site testing, limited operating condition coverage, and the fact that traditional hardware-in-the-loop simulation can only qualitatively determine the presence or absence of oscillation but cannot quantify stability margin and does not cover all operating conditions of the energy storage converter. This method makes up for the shortcomings of existing technologies in that they cannot comprehensively and accurately assess the broadband oscillation risk of energy storage power stations under multiple operating conditions and cannot meet the needs of actual engineering applications.

[0029] Example 1: Please see Figure 1 The embodiments of this application provide a method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, including S1~S2, and the specific implementation steps are as follows: S1. By injecting harmonic voltage into a test device containing a hardware-in-the-loop simulation platform, the broadband impedance curve of the electrochemical energy storage power station is collected. The hardware-in-the-loop simulation platform is built based on a dual-access mode, which is either a real-time simulator connected directly to the energy storage controller of the electrochemical energy storage power station via a digital-to-analog converter, or a black-box model that encapsulates the corresponding control program of the electrochemical energy storage power station.

[0030] Step S1 in this embodiment includes S1.1 to S1.2, specifically as follows: S1.1. Based on a dual-access mode, a semi-physical simulation platform is built by directly connecting a real-time simulator to the energy storage controller of the electrochemical energy storage power station via a digital-to-analog converter, or by connecting to a black-box model containing the corresponding control program of the electrochemical energy storage power station. Specifically: (1) Building the platform infrastructure: A customized hardware-in-the-loop simulation platform for energy storage systems was selected as the test carrier. A three-layer dedicated architecture was built, consisting of a host computer monitoring and testing layer, a real-time simulation core layer, and a physical interface and controller access layer. The functional positioning and signal interaction logic of each layer were clarified, thus forming the overall layout framework, hierarchical interaction rules, and installation boundaries of each module of the platform.

[0031] (2) Complete the deployment of hardware equipment: Based on the platform framework and installation boundaries determined in the previous step, a real-time simulator with microsecond-level simulation step size is installed in the core layer of real-time simulation. Dedicated simulation units for power grids and lithium batteries, power interfaces, and high-precision protection measurement equipment are deployed simultaneously. Hardware wiring, signal calibration, and power-on debugging are completed, thereby building a hardware simulation system with real-time simulation, signal acquisition, power simulation, and accurate measurement capabilities.

[0032] (3) Integrated software system module: Based on the already deployed hardware simulation system, a full-element electromagnetic transient model of the primary system of energy storage grid connection, including transformers, lines, circuit breakers, energy storage converters, and SVG reactive power compensation devices, is loaded into the platform. A full-scale, refined battery electrochemical model with unit-level charge / discharge and temperature rise characteristics is configured, a dedicated analysis tool for energy storage grid connection adaptability is installed, and a dedicated communication protocol module for the entire energy storage chain, compatible with BMS, PCS, and EMS, is connected. This completes the linkage adaptation and debugging of software and hardware, forming a core simulation system that enables collaborative software and hardware operation. This system possesses core capabilities for simulating all operating conditions of energy storage power stations, data interaction, and characteristic analysis. The "full-element electromagnetic transient model of the primary system of energy storage grid connection" is a mature and universally used standard electromagnetic transient model in the field of power system simulation. It fully includes all primary equipment on the grid-connected side of the energy storage power station and can accurately simulate broadband electromagnetic transients, harmonic responses, and fault transient characteristics. The "full-scale, refined battery electrochemical model" is a classic and mature mechanistic model in the field of battery modeling, accurately simulating the internal electrochemical reactions, charge / discharge kinetics, and temperature rise characteristics of the battery with the cell as the smallest unit.

[0033] (4) Implement dual access to the control system: Based on the established simulation core system, closed-loop integration between the energy storage control system and the simulation platform is achieved in two ways: First, the real-time simulator is directly connected to the actual energy storage controller of the electrochemical energy storage power station through a digital-to-analog converter, establishing a real-time interactive channel between measurement signals and control commands. Second, the actual control program of the electrochemical energy storage power station is encapsulated as a black-box model in the form of a dynamic link library, and linked with the full-element electromagnetic transient model of the primary system of the energy storage grid through a dedicated interface to restore the real control logic. This completes the construction of a closed-loop simulation platform equipped with the real control strategy, fully reproduces the actual operation and control logic of the energy storage power station, and becomes a complete test environment for conducting broadband oscillation risk tests.

[0034] (5) Conduct accuracy verification of simulation results: Using the completed closed-loop simulation platform as the test object, and based on the type test items of energy storage converters, SVG and other equipment and the "GB / T 44117-2024 Test Procedure for Model Parameters of Electrochemical Energy Storage Power Stations", simulation conditions were set up for active power control test, reactive power control test, low voltage ride-through test, high voltage ride-through test, primary frequency regulation test and inertia response test. The simulation results were compared and verified with the experimental measured data to obtain a semi-physical simulation platform that has passed accuracy verification. This ensures that the platform simulation results are consistent with the characteristics of actual power stations and can be directly used for subsequent multi-condition impedance scanning and broadband oscillation risk quantification analysis.

[0035] In addition, the hardware-in-the-loop simulation platform integrates a single energy storage converter AC port, an SVG AC port, and an energy storage power station grid connection point as measurement points; Among them, the AC port of a single energy storage converter is formed by configuring dedicated measurement points on the topology node of the AC output side of a single energy storage converter in a real-time simulator; The SVG AC port is formed by configuring dedicated measurement points on the AC grid-connected topology node of the static var generator in a real-time simulator. The grid connection point of an energy storage power station is formed by converging the AC output branches of all equipment on the power station side to a common connection point and configuring a total measurement point.

[0036] It should be noted that the testing device in this application is based on the aforementioned hardware-in-the-loop simulation platform, and its hardware architecture mainly includes the following parts: (1) Real-time simulator: The real-time simulator is the core equipment of the hardware-in-the-loop simulation platform, used to simulate the wideband dynamic characteristics of electrochemical energy storage power stations and near-field AC systems at grid connection points in real time. The equipment adopts a high-performance CPU or FPGA hardware platform, which has microsecond-level high real-time performance, high-speed data processing and precise time synchronization capabilities. It can load the full-element electromagnetic transient model of the primary system of energy storage grid connection and the full-scale refined battery electrochemical model, and complete the numerical solution of the system at a fixed step size, accurately reproducing the operating status of the power station under multiple operating conditions. It can simulate the electrical characteristics of components such as transformers, transmission lines, energy storage converters (PCS), and SVG reactive power compensation devices, and restore the switching actions and control logic of power electronic equipment. The CPU simulation step size is 10–50 microseconds, which can be adapted to the real-time simulation of AC systems; the FPGA simulation step size is 0.1–5 microseconds, which can be adapted to the real-time simulation of power electronic systems such as energy storage converters and SVG.

[0037] (2) Interface device: The interface device is deployed at the physical interface and the controller access layer, with a digital-to-analog conversion device as the core, to realize dual-mode signal interaction between the real-time simulator and the control system of the electrochemical energy storage power station. It includes analog interfaces and digital interfaces: the analog interfaces transmit analog signals such as harmonic voltage, harmonic current, and sequence impedance, to complete two-way interaction of measurement signals and control instructions between the real-time simulator and the energy storage controller; the digital interfaces transmit digital signals such as working condition switching, fault triggering, and protection action, to ensure stable communication of the black-box model between the real-time simulator and the actual energy storage controller / package control program, and support the closed-loop operation of the dual-access mode.

[0038] (3) Power interface and amplification unit: Corresponding to the power interface deployed on the platform, it is used for power conditioning and amplification of the small signals output by the real-time simulator, to meet the driving and simulation requirements of power equipment such as energy storage converters and SVGs. It can accurately amplify the voltage and current signals output by simulation, reproduce the power conversion process under wide-band harmonic excitation without distortion, and features high precision, high bandwidth and good linearity, so as to ensure that the power signals completely match the simulation instructions, and adapt to multi-working-condition wide-band impedance scanning tests.

[0039] (4) High-precision data acquisition and monitoring equipment: It is used to collect electrical quantities such as harmonic voltage, harmonic current, power and frequency required for wide-band impedance scanning at three dedicated measurement points, namely the AC port of a single energy storage converter, the AC port of the SVG, and the grid connection point of the energy storage power station, and synchronously collect the operating parameters of the battery system, the energy storage converter and the SVG. The data is uploaded to the upper computer monitoring test layer via a high-speed acquisition card to complete storage, analysis and impedance fitting; at the same time, it monitors the operating status of the platform in real time, and gives immediate alarms for situations such as overvoltage, overcurrent and signal abnormality, so as to ensure the safety and reliability of the whole process of multi-working-condition tests.

[0040] In addition, the complete set of dedicated test control and analysis software system running on the hardware-in-the-loop simulation platform and supporting the hardware includes multiple functional modules, which work together to realize the full-process automation of multi-working-condition wide-band oscillation risk tests and the analysis and processing of impedance data: (1) Simulation Modeling Module: It has a variety of preset power system equipment models built in, and supports the construction of complete simulation models of electrochemical energy storage power stations and near-field AC systems through graphical drag and drop; at the same time, it supports the customization of energy storage equipment models and power grid topology models through a dedicated scripting language, and can load BMS, PCS, and EMS full-link communication protocol modules, perfectly adapting to the simulation requirements under dual access mode. Among them, the "Complete Simulation Model of Electrochemical Energy Storage Power Station and Near-field AC System" is an integrated electromagnetic transient simulation model that integrates the energy storage power station body, grid-connected device and all electrical components of the surrounding AC power grid, and can simulate the overall wideband dynamic operation characteristics. The "Energy Storage Equipment Model" is a standardized simulation unit model that describes the electrical characteristics and control logic of core energy storage equipment such as energy storage converters, lithium batteries, BMS, and SVG. The "Power Grid Topology Model" is a network structure simulation model that represents the connection relationship and electrical parameters of power grid lines, transformers, buses, circuit breakers and other components.

[0041] (2) Operating condition setting module: It supports three major categories of preset typical operating conditions. It can set the active power level, reactive power type and power factor of the energy storage converter charging and discharging, the reactive power output level of SVG capacitive / inductive, the power grid summer high / summer low / winter high / winter low operation mode, and the line N-1 / N-2 fault type with one click. The module sends the operating condition parameters to the real-time simulator and automatically completes the switching of multiple operating conditions and the adjustment of the operating status.

[0042] (3) Frequency scanning control module: Strictly follow the scanning range of 1Hz to 1000Hz and the fixed step of 1Hz to control the real-time simulator to perform harmonic voltage injection and impedance scanning at three dedicated measurement points: the AC port of a single energy storage converter, the AC port of the SVG, and the grid connection point of the energy storage power station; synchronously coordinate the digital-to-analog conversion equipment and the data acquisition equipment to work together, collect harmonic voltage and harmonic current response data in real time and push them to the data processing module.

[0043] (4) Data processing module: After filtering and noise reduction preprocessing of the collected data, the positive / negative sequence impedance at each frequency point is calculated based on the sequence impedance theory, and a broadband impedance curve is generated by fitting. Then, the magnitude margin and phase margin quantification index are calculated by using the Nyquist stability criterion and Bode plot method, and the impedance characteristics and stability margin under multiple working conditions are compared and statistically analyzed to provide core basis for risk assessment.

[0044] (5) Results display and storage module: Displays the broadband impedance curves, amplitude margin, phase margin and risk judgment results of the three measurement points in a graphical interface; supports storing test conditions, impedance data, stability margin indicators and risk warning information into the database for retrospective query; and links the warning mechanism to display risk warning information in a pop-up window.

[0045] The testing software features a fully open API interface, supporting automated testing under multiple operating conditions, batch impedance analysis, and automatic report generation processes via Python scripts. It can output standardized broadband oscillation risk test reports for electrochemical energy storage power stations with a single click, significantly reducing manpower input.

[0046] This embodiment S1.1 integrates the AC port of a single energy storage converter, the AC port of an SVG, and the grid connection point of the energy storage power station, achieving comprehensive testing of both local equipment and the entire power station. This solves the problem of traditional platforms having only one test point and being unable to cover both local and overall aspects. The configuration of dedicated measurement points, such as dedicated points on the AC output side of the single energy storage converter and the AC grid connection side of the SVG, ensures the accuracy of data acquisition and avoids data distortion caused by unreasonable measurement points. The grid connection point of the energy storage power station forms a common connection point through a busbar and is configured with a total measurement point, which can comprehensively reflect the broadband characteristics of the entire power station, taking into account both local testing of individual equipment and system testing of the entire power station, improving the comprehensiveness and flexibility of the test. This port configuration makes the hardware-in-the-loop simulation platform more closely match actual testing needs, providing reliable hardware support for multi-condition, multi-dimensional broadband oscillation risk testing, improving testing efficiency and data accuracy. In summary, this application utilizes a black-box model that connects to the actual energy storage controller or encapsulates the power station control program via a digital-to-analog converter. Compared to a purely theoretical model, this model better reflects the actual operation and control characteristics of the power station. Compared to on-site testing, it has lower costs, eliminates on-site operational risks, and covers various extreme faults and grid operating conditions. Furthermore, through complete primary system modeling, dual access to the actual secondary control system, three categories of preset typical operating condition configurations, and collaborative testing at three dedicated measurement points—the AC port of a single energy storage converter, the AC port of the SVG, and the grid connection point of the energy storage power station—it achieves full coverage of broadband oscillation risk points across all scenarios in electrochemical energy storage power stations. It can also quantitatively output full-band amplitude margin and phase margin indicators, abandoning the binary results of traditional time-domain simulation that can only qualitatively determine stability, thus providing stronger practical guidance value for engineering projects.

[0047] S1.2 Under various preset typical operating conditions, conduct wideband impedance scanning tests on the test device with the hardware-in-the-loop simulation platform as the core to complete the plotting of the wideband impedance curve. Specifically, first set the frequency scanning range to 1Hz to 1000Hz, with a fixed step length of 1Hz, inject harmonic voltages into the test device containing the hardware-in-the-loop simulation platform at three measurement points: the AC port of a single energy storage converter, the AC port of the SVG, and the grid connection point of the energy storage power station, and simultaneously measure the harmonic currents corresponding to all frequency points; wherein, the harmonic voltage is a positive sequence harmonic voltage or a negative sequence harmonic voltage not exceeding 0.1 per unit (pu) (i.e., the first threshold).

[0048] The order impedance is obtained by performing phasor ratio calculations based on harmonic voltages and harmonic currents of the same order. Based on the sequence impedance at all frequencies, broadband impedance curves corresponding to the three measurement points in the electrochemical energy storage power station are generated by fitting.

[0049] The preset typical operating conditions are defined based on the operating characteristics and actual needs of the power system, and with reference to industry standards such as "NB / T 10651 Technical Specification for Impedance Characteristic Evaluation of Wind Farms" and "NB / T 11344 Technical Specification for Impedance Characteristic Evaluation of Photovoltaic Power Stations". They are broadly categorized into three types: full operating conditions for energy storage converters, full reactive power operating conditions for SVG, and grid operating conditions. A complete test condition system can be formed through multi-parameter combinations. The specific conditions for each are as follows: (1) The full operating condition of the energy storage converter is achieved by adjusting the active power output level in the charging and discharging modes, and matching different preset reactive power types and power factors; specifically: for the charging and discharging modes of the energy storage converter, the active power output is divided into ten gradient levels from 10% to 100% according to the rated power in each mode and adjusted to obtain the active power output data of each level; based on the active power output data of each level, the maximum capacitive reactive power, power factor and maximum inductive reactive power under the corresponding active power output are matched respectively, and the combination constitutes the full operating condition of the energy storage converter, including: ① The active power output (charging mode) of the energy storage converter is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the rated power, and the reactive power is the maximum capacitive reactive power under the corresponding active power output. ② The active power output (charging mode) of the energy storage converter is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the rated power, and the power factor is 1. ③ The active power output (charging mode) of the energy storage converter is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the rated power, and the reactive power is the maximum inductive reactive power under the corresponding active power output. ④ The active power output (discharge mode) of the energy storage converter is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the rated power, and the reactive power is the maximum capacitive reactive power under the corresponding active power output. ⑤ The active power output (discharge mode) of the energy storage converter is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the rated power, and the power factor is 1. ⑥ The active power output (discharge mode) of the energy storage converter is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of the rated power, and the reactive power is the maximum inductive reactive power under the corresponding active power output. (2) The full reactive power operation of SVG is achieved by adjusting the reactive power output level. Specifically, based on the rated reactive power, ten adjustment levels are divided from 10% to 100%, respectively, to build full-level operation conditions for both capacitive and inductive reactive power output modes, fully covering the entire operating range of SVG reactive power adjustment, including: ①SVG reactive power output is capacitive reactive power at 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of rated power; ②SVG reactive power output is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% of rated power inductive reactive power; (3) The power grid operating conditions are achieved by configuring preset conventional operating modes and line fault types. The conventional scenarios include four typical conventional operating modes: summer heavy, summer light, winter heavy, and winter light. The fault scenarios cover two line fault types, N-1 and N-2, of the main AC lines in the power grid's vicinity, including: ①The power grid operates under typical conventional modes such as high summer load, low summer load, high winter load, and low winter load; ② Faults in the main AC lines near the power grid: N-1 fault and N-2 fault.

[0050] The three operating conditions mentioned above are not independent and can be flexibly arranged and combined according to actual testing needs to form a complete set of test conditions covering all operating scenarios of the electrochemical energy storage power station. The complete test conditions refer to the operating scenarios of the electrochemical energy storage power station when the broadband impedance curves are collected.

[0051] In this embodiment, S1.2 obtains the sequence impedance based on the phasor ratio of harmonic voltage and current of the same order, which can accurately reflect the impedance characteristics of the energy storage power station at different frequencies, solving the problems of inaccurate impedance calculation and lack of specificity in traditional testing methods. By fitting the sequence impedance at all frequencies to generate a broadband impedance curve, the impedance variation law of the energy storage power station over a wide frequency range can be intuitively presented, providing reliable and comprehensive data support for the subsequent acquisition of stability margin indicators. This significantly improves the scientificity and accuracy of broadband oscillation risk testing, provides a solid foundation for risk assessment, and effectively avoids risk misjudgment caused by incomplete data. Furthermore, this embodiment clearly defines the specific types and coverage of preset typical operating conditions, making up for the shortcomings of traditional test conditions being singular and incomplete in coverage, ensuring that the test results can be adapted to various scenarios in the actual operation of energy storage power stations. The full coverage of all operating conditions of the energy storage converter, all reactive power conditions of the SVG, and grid operation conditions can comprehensively capture the broadband characteristics of the energy storage power station under different operating states, avoiding the undetected potential oscillation risks due to omissions in operating conditions. The implementation methods of each operating condition are tailored to actual operation and maintenance scenarios. For example, the energy storage converter adjusts the active power level of charging and discharging, and combines reactive power type and power factor; the SVG adjusts the reactive power output level; and the grid operation conditions are configured with conventional operating modes and line fault types. This makes the test conditions more practical and targeted, realistically simulating the complex operating conditions in actual power station operation, improving the comprehensiveness and practicality of risk testing, and providing more comprehensive protection for the safe and stable operation of the power station. For each active power output level, the system matches the maximum capacitive reactive power, power factor, and maximum inductive reactive power under the corresponding scenario, achieving a precise match between active and reactive power. This allows for realistic simulation of the energy storage converter's operation under different loads and reactive power configurations, solving the problems of unreasonable active and reactive power matching and disconnect from actual operating scenarios in traditional operating condition settings. This refined operating condition configuration can accurately capture the broadband oscillation characteristics of energy storage power stations under different combinations of operating parameters, improving the targeting and accuracy of testing. It can effectively identify potential oscillation risks under specific operating conditions, providing precise data support for parameter optimization and risk control of energy storage converters.

[0052] Furthermore, this embodiment clarifies the specific parameters of harmonic voltage, limiting it to no more than 0.1 per unit. This ensures that harmonic signals can be effectively acquired and test requirements are met, while preventing excessively high harmonic voltages from impacting energy storage power station equipment and the hardware-in-the-loop simulation platform, thus protecting equipment safety. It also solves the problem of equipment damage or data distortion caused by unreasonable harmonic voltage amplitudes in traditional testing. The reasonable harmonic voltage parameter settings balance test effectiveness, equipment safety, and test authenticity, standardize the test process, ensure the comparability of test results under different test scenarios, improve the standardization and universality of broadband oscillation risk testing, and adapt to the testing needs of different types of electrochemical energy storage power stations.

[0053] S2. Obtain the stability margin index based on the broadband impedance curve. If the stability margin index does not meet the preset threshold, it is determined that the electrochemical energy storage power station has a broadband oscillation risk.

[0054] Step S2 in this embodiment includes S2.1 to S2.2, specifically as follows: S2.1. For the broadband impedance curves corresponding to the three measurement points, quantitative analysis of stability margin is carried out based on the sequence impedance theory of three-phase power systems: the system is divided into equipment / power station side and grid side at the selected measurement points, and the positive and negative sequence impedances of both sides are obtained respectively. The impedance of equipment / power station side is denoted as Z1 and the impedance of grid side is denoted as Zg. The impedance ratio T=Z1 / Zg is calculated. Based on this, the stability is qualitatively determined by the Nyquist stability criterion and the stability margin is quantitatively calculated by the Bode plot method.

[0055] When using the Nyquist stability criterion, the Nyquist curve of the impedance ratio T is plotted. Based on the encirclement of the curve around the point (-1,j0) on the complex plane and the distribution of the open-loop poles of the system, the stability of the closed-loop system is determined. At the same time, the distance between the curve and the point (-1,j0) is used to complete the preliminary quantification of the stability margin.

[0056] Based on this, Bode plot analysis is performed to plot the amplitude-frequency response curves and phase-frequency response curves of Z1 and Zg respectively. These two characteristic curves are used as the basis for calculation: at the phase critical frequency point where the phase curve reaches -180°, the impedance amplitudes of the power station side and the grid side in the amplitude-frequency response curve are read, and the amplitude margin is obtained by converting the ratio of the two; at the amplitude critical frequency point where the amplitude-frequency response curve reaches 0dB, the phase difference between the power station side and the grid side in the phase-frequency response curve is read, and the phase margin is calculated based on this phase margin. Ultimately, the stability margin index is composed of the gain margin and the phase margin, thus obtaining the stability margin index corresponding to each of the three measurement points.

[0057] This embodiment, S2.1, utilizes a combination of amplitude margin and phase margin to comprehensively reflect the broadband stability characteristics of the energy storage power station. These two indicators complement and corroborate each other, avoiding the limitations of relying on a single indicator and ensuring a more scientific and comprehensive assessment of the power station's broadband oscillation risk. This quantitative stability margin indicator not only accurately determines whether the power station faces oscillation risk but also intuitively reflects the severity of the risk. It provides a clear quantitative basis for formulating subsequent risk control measures, facilitating maintenance personnel to optimize equipment parameters in a targeted manner, mitigate oscillation risks, and improve the stability of the power station's operation.

[0058] S2.2 Based on the stability margin index, for any of the three measurement points, if either the amplitude margin or the phase margin does not meet the corresponding preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk. The broadband oscillation risk warning mechanism is immediately triggered, a risk alarm command is generated in real time and pushed to the host computer monitoring platform, and a global alarm is completed through interface pop-ups, audio and visual prompts, and automatic archiving of warning logs. If both the amplitude margin and the phase margin meet the corresponding preset thresholds, the electrochemical energy storage power station is determined not to have a broadband oscillation risk, the broadband oscillation risk warning mechanism is not triggered, and the normal operation log is automatically archived simultaneously.

[0059] Based on the broadband oscillation risk assessment results, a broadband oscillation risk test report for the electrochemical energy storage power station is generated, including the following: (1) Basic information of electrochemical energy storage power station and grid connection system: Detail the installed capacity of the power station, the configuration parameters of the energy storage converter (PCS) and SVG, the grid connection point topology, the grid connection voltage level and the parameters of the near-field system, and clarify the basic information of the test object.

[0060] (2) Evaluation of hardware-in-the-loop simulation platform and simulation model: The three-layer architecture hardware-in-the-loop simulation platform construction scheme and dual access mode implementation method are introduced. The composition of the full-element electromagnetic transient model and the full-quantity refined battery electrochemical model of the primary system of energy storage grid connection is explained. The accuracy verification and evaluation conclusion of the simulation results and field measured data are attached.

[0061] (3) Wideband oscillation risk test conditions: Clearly define the specific configuration of three major categories of preset typical operating conditions: full operating conditions of energy storage converter, full reactive operating conditions of SVG, and grid operating conditions, including test conditions such as charging and discharging active power level, reactive power output, grid operating mode and fault type.

[0062] (4) Multi-point and multi-condition broadband impedance characteristics: Show the positive / negative sequence impedance curves of three measurement points: AC port of a single energy storage converter, AC port of SVG, and grid connection point of energy storage power station, in a wide frequency range of 1Hz to 1000Hz, and analyze the impedance amplitude and phase change law under each typical operating condition.

[0063] (5) Quantitative assessment of broadband oscillation stability: Explain the assessment method based on sequence impedance theory, Nyquist stability criterion and Bode plot method, give quantitative indicators of amplitude margin and phase margin under each working condition, and clarify the broadband oscillation risk judgment results at each measurement point.

[0064] (6) Risk summary and prevention and control optimization suggestions: Summarize the risk assessment conclusions of all operating conditions and all measurement points, locate potential oscillation risk points, and propose targeted engineering suggestions such as PCS / SVG control parameter optimization, power grid operation mode adjustment, and oscillation suppression strategies.

[0065] For examples of this application, please refer to [link / reference]. Figure 2 , 3 , Figure 2 This is a system architecture diagram provided in an embodiment of the present application, which shows the overall hardware and architecture composition of the test device including the hardware-in-the-loop simulation platform in the present application; Figure 3 This is a diagram of the simulation model provided in the embodiments of this application, showing the composition of a complete simulation model of an electrochemical energy storage power station and a near-field AC system.

[0066] In this embodiment S2.2, amplitude margin and phase margin are core indicators reflecting the broadband stability characteristics of a power station. Failure of either indicates a potential oscillation hazard. This judgment logic can promptly identify the risk caused by a single indicator exceeding the standard, solving the problem of delayed risk identification caused by the traditional approach of "only determining risk when both indicators fail to meet the standard." Simultaneously, the clear judgment logic provides testing personnel with clear operational standards, reducing errors in human judgment, improving the consistency and accuracy of risk assessment, and facilitating timely detection of potential hazards and implementation of preventative measures by maintenance personnel. This effectively reduces the probability of broadband oscillation accidents and ensures the safe and stable operation of the energy storage power station.

[0067] Overall, this embodiment has the following beneficial effects: This application employs a dual-access mode in platform construction. It can directly connect to the energy storage controller via a real-time simulator and digital-to-analog converter to recreate the control logic and hardware interaction scenarios of the actual power station operation. Simultaneously, it can access a black-box model encapsulating the control program, adapting to the control modes of energy storage power stations from different manufacturers and with different specifications. This breaks the limitations of existing single-access testing platforms, flexibly simulating various operating conditions such as power station startup, grid connection, load fluctuations, and fault recovery, enabling risk testing under multiple operating conditions and solving the pain point of existing methods' inability to fully adapt to multiple operating conditions. In the data acquisition stage, by injecting harmonic voltage into the testing device containing the hardware-in-the-loop simulation platform, it can accurately capture the broadband impedance curves of the electrochemical energy storage power station at different frequencies. Impedance characteristics are a core indicator reflecting the oscillation risk of the power station. Broadband coverage can fully present the response characteristics of the power station in different frequency ranges, avoiding the risk omissions caused by existing tests only targeting specific frequencies and incomplete data acquisition. In terms of risk assessment, stability margin indicators are extracted based on broadband impedance curves and quantitatively judged through preset thresholds. This replaces the shortcomings of existing methods that rely heavily on qualitative analysis and lack unified quantitative standards. It can accurately quantify the safety risk level of broadband oscillations in power plants and clearly determine whether there are oscillation hazards in power plants, thereby achieving accurate quantitative assessment of broadband oscillation risks and effectively solving the problem that existing tests are difficult to accurately quantify risks. In summary, this application constructs a test device with a hardware-in-the-loop (HIL) simulation platform through a dual-access mode. It connects to the actual energy storage controller or a black-box model encapsulating the power station control program via a digital-to-analog converter. Compared to purely theoretical models and equivalent simplified models, this approach better reflects the actual operation and control characteristics of the power station. Compared to on-site power station testing, it offers significant advantages such as lower cost, no on-site operational safety risks, and full coverage of various extreme faults and grid operating conditions. Furthermore, relying on a combined scheme of complete primary system modeling, dual-mode access to the secondary control system, refined configuration of three categories of preset typical operating conditions, and collaborative testing of three dedicated measurement points—the AC port of a single energy storage converter, the AC port of the SVG, and the grid connection point of the energy storage power station—it achieves comprehensive coverage of broadband oscillation risks across all scenarios in electrochemical energy storage power stations. It can quantitatively output full-band amplitude margin and phase margin stability indicators, completely breaking through the limitations of traditional time-domain simulation, which can only qualitatively determine stability using a binary 0 / 1 result. This significantly enhances its practical engineering guidance and application value.

[0068] Example 2: Please see Figure 4 The embodiments of this application provide an oscillation risk testing device for an electrochemical energy storage power station covering multiple operating conditions, including an impedance acquisition module 10 and a risk determination module 20; Among them, the impedance acquisition module 10 is used to acquire the broadband impedance curve of the electrochemical energy storage power station by injecting harmonic voltage into the test device containing the semi-physical simulation platform; wherein, the semi-physical simulation platform is built based on the dual access mode, by directly connecting the energy storage controller of the electrochemical energy storage power station through a real-time simulator and a digital-to-analog converter, or by connecting to a black box model that encapsulates the corresponding control program of the electrochemical energy storage power station. The risk assessment module 20 is used to obtain the stability margin index based on the broadband impedance curve. If the stability margin index does not meet the preset threshold, it is determined that the electrochemical energy storage power station has a broadband oscillation risk.

[0069] It should be noted that the technical concept of this second embodiment is completely consistent with that of the first embodiment. The two maintain a high degree of synergy at the technical logic level. The specific technical details can be referred to the relevant description of the first embodiment, which will not be repeated here.

[0070] Example 3: This application provides a computer-readable storage medium, which includes a stored computer program, wherein the computer program controls the device where the computer-readable storage medium is located to execute the described method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions when it is running. The aforementioned method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, when implemented as a software functional unit and used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above-described embodiments can also be implemented by a computer program instructing related hardware. This computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0071] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0072] The above are preferred embodiments of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, characterized in that, include: By injecting harmonic voltage into a test device containing a hardware-in-the-loop simulation platform, the broadband impedance curve of the electrochemical energy storage power station is acquired. The hardware-in-the-loop simulation platform is based on a dual-access mode, which is built by directly connecting a real-time simulator to the energy storage controller of the electrochemical energy storage power station via a digital-to-analog converter, or by connecting to a black-box model that encapsulates the corresponding control program of the electrochemical energy storage power station. The stability margin index is obtained based on the wideband impedance curve. If the stability margin index does not meet the preset threshold, the electrochemical energy storage power station is determined to have a wideband oscillation risk.

2. The method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in claim 1, characterized in that, By injecting harmonic voltage into a test device containing a hardware-in-the-loop simulation platform, the broadband impedance curve of the electrochemical energy storage power station was acquired, specifically: Under preset typical operating conditions, harmonic voltage is injected into the test device containing the hardware-in-the-loop simulation platform, and the harmonic current corresponding to the full frequency points is measured simultaneously. Based on the phasor ratio calculation of the harmonic voltage and harmonic current of the same order, the order impedance of the corresponding order is obtained. Based on the sequence impedance at all frequency points, a broadband impedance curve for the electrochemical energy storage power station is generated by fitting.

3. The method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in claim 2, characterized in that, The preset typical operating conditions include the full operating conditions of the energy storage converter, the full reactive power operating conditions of the SVG, and the grid operation conditions. Specifically, the active power output levels of the energy storage converter are divided and adjusted according to the charging and discharging modes, and the adjustment results are processed by different preset reactive power types and power factors to construct the full operating conditions of the energy storage converter. Based on the rated reactive power of the SVG, the reactive power output is divided and adjusted to construct the full reactive power operating condition of the SVG, which covers the entire operating range of the SVG reactive power adjustment. By configuring preset normal operating modes and line fault types for the power grid, corresponding normal and fault scenarios are set to construct the power grid operating conditions, which cover various normal and fault scenarios. Based on actual testing requirements, the full operating conditions of the energy storage converter, the full reactive power condition of the SVG, and the grid operation condition are arbitrarily arranged and combined to obtain a complete set of test conditions covering all operating scenarios of the electrochemical energy storage power station; the complete test conditions are the operating scenarios of the electrochemical energy storage power station when the broadband impedance curve is collected.

4. The method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in claim 3, characterized in that, The active power output levels of the energy storage converter are divided and adjusted according to its charging and discharging modes. The adjustment results are then processed using different preset reactive power types and power factors to construct a full-condition operating system for the energy storage converter. Specifically: For the charging and discharging modes of the energy storage converter, the active power output is divided into several levels according to the target rated power in each mode and then adjusted to obtain the active power output data of each level. Based on the active power output data for each level, the maximum capacitive reactive power, power factor, and maximum inductive reactive power under the corresponding active power output are matched respectively, and combined to form the full operating conditions of the energy storage converter.

5. The method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in claim 1, characterized in that, The stability margin index is obtained based on the aforementioned wideband impedance curve, specifically as follows: For the aforementioned broadband impedance curve, at the phase critical frequency point, the amplitude margin is calculated by combining the ratio of the impedance amplitude on the power station side to the impedance amplitude on the grid side. At the critical frequency point of amplitude, the phase margin is calculated by combining the phase of the power station side impedance and the phase margin of the grid side impedance. The stability margin index is composed of the magnitude margin and the phase margin.

6. The method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in claim 5, characterized in that, If the stability margin index does not meet the preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk, specifically: If either the amplitude margin or the phase margin fails to meet the corresponding preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk.

7. The method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in claim 1, characterized in that, The hardware-in-the-loop simulation platform is integrated with a single energy storage converter AC port, an SVG AC port, and an energy storage power station grid connection point as measurement points. The AC port of a single energy storage converter is formed by configuring a dedicated measurement point on the topology node of the AC output side of the single energy storage converter in the real-time simulator. The SVG AC port is formed by configuring a dedicated measurement point on the AC grid-connected topology node of the static var generator in the real-time simulator. The grid connection point of the energy storage power station is formed by converging the AC output branches of all equipment on the power station side to a common connection point and configuring a total measurement point.

8. A method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions as described in any one of claims 1 to 7, characterized in that, The harmonic voltage is a positive-sequence harmonic voltage or a negative-sequence harmonic voltage that does not exceed a first threshold.

9. A device for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, characterized in that, Includes an impedance acquisition module and a risk assessment module; The impedance acquisition module is used to acquire the broadband impedance curve of the electrochemical energy storage power station by injecting harmonic voltage into the test device containing the hardware-in-the-loop simulation platform. The hardware-in-the-loop simulation platform is built based on a dual-access mode, which is a real-time simulator connected directly to the energy storage controller of the electrochemical energy storage power station via a digital-to-analog converter, or connected to a black box model that encapsulates the corresponding control program of the electrochemical energy storage power station. The risk assessment module is used to obtain a stability margin index based on the broadband impedance curve. If the stability margin index does not meet a preset threshold, the electrochemical energy storage power station is determined to have a broadband oscillation risk.

10. A storage medium, characterized in that, The storage medium stores a computer program, which is called and executed by a computer to implement a method for testing the oscillation risk of an electrochemical energy storage power station covering multiple operating conditions, as described in any one of claims 1 to 8.

11. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by the communication device, they implement the oscillation risk testing method for an electrochemical energy storage power station covering multiple operating conditions as described in any one of claims 1 to 8.

Images