Power system frequency response characteristic parameter measurement method and related device

Abstract

The invention discloses a power system frequency response characteristic parameter measurement method and a related device, and the method builds a parameter inversion method based on a frequency dynamic response characteristic by actively injecting power disturbance of a set frequency into a grid-connected point of a power system and combining the high-precision extraction of a system frequency variation. The equivalent inertia and the equivalent damping of the system can be quantitatively calculated; the injected disturbance signal has a fixed frequency and a settable amplitude, so that high-precision measurement can be realized in a normal operation state, a large disturbance event or environmental noise depending on a system is avoided, and good experimental repeatability and engineering adaptability are achieved; compared with an off-line evaluation method depending on fault disturbance, response testing and parameter estimation of the system in a non-fault state are achieved through active disturbance, the potential of online and periodic measurement and supporting capacity dynamic updating is achieved, and efficient technical support is provided for new energy field station grid-connected evaluation and dispatching access assessment.

Description

Technical Field

[0001] This invention pertains to power system inertia level measurement technology, and particularly relates to a method and related apparatus for measuring the frequency response characteristic parameters of a power system. Background Technology

[0002] With the rapid development of new energy sources and the gradual phasing out of traditional thermal power units, the inertia level of power systems is gradually decreasing. In the future, a large number of power electronic devices, including new energy sources, energy storage, and flexible DC transmission systems, will be integrated into the grid, and the safety and stability of the power system will increasingly rely on the control of these devices. Existing research has proposed various control methods to achieve inertia and damping support for the power grid provided by power electronic devices. However, due to the influence of control components such as sampling, filtering, and limiting, the actual inertia and damping characteristics provided by power electronic devices may differ from the design parameters, requiring physical testing to determine their true levels.

[0003] Existing methods calculate inertia by measuring power feedback through frequency changes with a fixed slope and damping by measuring current feedback through voltage harmonics. While these methods offer high accuracy, they are primarily used for single-unit testing. Applying frequency changes or voltage harmonics through a grid simulation source is not applicable to station-level testing due to the limited capacity of the grid simulation source. For station-level measurements, existing methods assess inertia and damping levels through converter responses after large system disturbances. However, the randomness of large disturbances makes routine system monitoring impossible. Some solutions propose utilizing noise in the system or random small disturbances generated by equipment switching for measurement, but these methods lack clear data characteristics and have low accuracy. Summary of the Invention

[0004] Based on this, the present invention aims to propose a method and related device for measuring the frequency response characteristic parameters of a power system. By actively injecting active power disturbances of a specific frequency into the system, the inertia and damping of the substation or individual unit are calculated by measuring the frequency change, thus solving the problems of low timeliness and low accuracy.

[0005] In a first aspect, the present invention provides a method for measuring the frequency response characteristic parameters of a power system, comprising:

[0006] Actively inject power disturbances of a set frequency into the system;

[0007] Measure the frequency change at the grid connection point of the system after the injected power disturbance;

[0008] Based on the frequency response characteristics of the power system, the equivalent inertia and equivalent damping of the system are calculated according to the frequency change and power disturbance at the grid connection point.

[0009] Furthermore, the above method also includes:

[0010] Measure the power and frequency changes at a single converter port under the influence of power disturbances;

[0011] Based on the frequency response characteristics of the power system, the inertia parameters and damping parameters of a single converter are calculated according to the power change and frequency change at a single converter port.

[0012] Furthermore, injecting power disturbances at a set frequency into the system includes:

[0013] A power disturbance of a set frequency is actively injected into the system grid connection point through an external disturbance injection device.

[0014] Furthermore, injecting power disturbances at a set frequency into the system includes:

[0015] Control any converter at the grid connection point of the system to actively inject a power disturbance of a set frequency into the grid connection point.

[0016] Furthermore, the power disturbance is a sinusoidal active power disturbance.

[0017] Furthermore, the frequency change at the grid connection point of the system after the injected power disturbance is measured, including:

[0018] Measure the AC voltage at the grid connection point of the system after the injected power disturbance;

[0019] The current frequency of the system's grid connection point is obtained based on the AC voltage using the zero-crossing detection method.

[0020] Harmonic analysis is performed on the current frequency of the system's grid connection point to extract the frequency change.

[0021] Furthermore, based on the frequency response characteristics of the power system, the equivalent inertia and equivalent damping of the system are calculated according to the frequency variation and power disturbance at the system grid connection point, including:

[0022] Determine the frequency variation and the phase difference of the power disturbance at the grid connection point of the system, and denote the grid connection disturbance phase difference;

[0023] A frequency dynamic response model of the system under the influence of power disturbance is established;

[0024] Substitute the frequency change and power disturbance at the grid connection point of the system into the frequency dynamic response model, and calculate the equivalent inertia and equivalent damping of the system based on the phase difference of the grid connection disturbance according to the frequency dynamic response model.

[0025] Furthermore, the frequency dynamic response model can be represented as follows:

[0026] ,

[0027] in, This indicates the power disturbance at a set frequency. This represents the sum of the capacities of all converters in the system. Represents the equivalent inertia. Indicates equivalent damping, This represents the frequency variation at the system's grid connection point. Indicates the system's rated frequency. Describes the differential operator. This indicates that the frequency change is differentiated.

[0028] In a second aspect, the present invention provides a power system frequency response characteristic parameter measuring device, comprising:

[0029] The disturbance injection module is used to actively inject power disturbances of a set frequency into the system;

[0030] The frequency measurement module is used to measure the frequency change at the grid connection point of the system after the injected power disturbance.

[0031] The parameter calculation module is used to calculate the equivalent inertia and equivalent damping of the power system based on the frequency response characteristics of the power system, according to the frequency change and power disturbance at the grid connection point.

[0032] Thirdly, the present invention provides an electronic device including a memory storing computer-executable instructions and a processor, wherein when the computer-executable instructions are executed by the processor, the device performs the steps of the power system frequency response characteristic parameter measurement method provided in the first aspect.

[0033] Fourthly, the present invention provides a readable storage medium storing a computer-executable program that, when executed, can implement the various steps of the power system frequency response characteristic parameter measurement method provided in the first aspect.

[0034] Compared with existing measurement methods, the present invention has the following advantages:

[0035] This invention proposes a method for measuring the frequency response characteristic parameters of a power system. By actively injecting a power disturbance of a set frequency into the grid connection point of the power system, and combining this with high-precision extraction of system frequency changes, a parameter inversion method based on the dynamic frequency response characteristics is established. This method can quantitatively calculate the equivalent inertia and equivalent damping of the system, improving the accuracy and engineering feasibility of frequency response characteristic modeling. The injected disturbance signal has a fixed frequency and a settable amplitude. In particular, the active power disturbance using a sinusoidal waveform has significant identification characteristics in the system frequency response, which helps to achieve high-precision measurement under normal operating conditions, avoiding reliance on large system disturbance events or environmental noise. It has good experimental repeatability and engineering adaptability. Compared with offline evaluation methods that rely on fault disturbances, this scheme achieves response testing and parameter estimation of the system under non-fault conditions through active disturbances. It has the potential for online, periodic measurement and dynamic updating of support capabilities, providing efficient technical support for grid connection evaluation and dispatch access assessment of new energy power plants. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 A power grid connection system architecture diagram provided for embodiments of the present invention;

[0038] Figure 2 A flowchart illustrating the implementation of the power system frequency response characteristic parameter measurement method provided in this embodiment of the invention;

[0039] Figure 3 A schematic diagram of the structure of a power system frequency response characteristic parameter measuring device provided in an embodiment of the present invention;

[0040] Figure 4 This is an electronic device architecture diagram provided for an embodiment of the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The following embodiments of the present invention provide a method for measuring the frequency response characteristic parameters of a power grid-connected system. By injecting a small active power disturbance, the equivalent inertia parameters and equivalent damping parameters at the grid connection point are calculated by measuring the frequency change at the grid connection point. Furthermore, the inertia parameters and damping parameters of a single converter can be calculated by measuring the active power change and frequency change at a single converter port. The measurement method proposed in this invention is implemented through active injection and can be applied to single-unit or grid-level testing.

[0043] See Figure 1 One embodiment of the present invention provides an architecture diagram of a power grid-connected system, applicable to power systems such as wind power, photovoltaic, energy storage, or flexible DC power connected to the grid via converters, and is used to illustrate the measurement method proposed in the present invention.

[0044] like Figure 1 As shown, n converters converge at an AC convergence point (grid connection point) and are then connected to the power grid via lines. For the measurement method proposed in this invention, there are two ways to actively inject power disturbances into the system: one is internal disturbance injection, where one converter is controlled to inject a disturbance into the grid connection point; the other is external disturbance injection, where a disturbance is injected into the grid connection point through a disturbance injection device such as a supercapacitor. This allows for the measurement of the frequency response characteristics of a single converter, as well as the response of the grid connection point, thereby obtaining the equivalent inertia and equivalent damping of the entire power station (i.e., all converters).

[0045] See Figure 2 An embodiment of the present invention provides a method for measuring the frequency response characteristic parameters of a power system, comprising the following steps:

[0046] Step S210. Actively inject a power disturbance of a set frequency into the system.

[0047] This step stimulates the system frequency response through active injection, causing a controlled disturbance in the system frequency. This provides input excitation for frequency response characteristic parameters, such as inertia / damping identification. According to the power system frequency response mechanism, when there is a disturbance in the grid-connected power (increase or decrease in active power), the system frequency will shift accordingly. In particular, small-amplitude sinusoidal disturbances (such as 1 Hz, 5% of rated power amplitude) can excite a measurable frequency response without interfering with system operation.

[0048] Furthermore, the disturbance injection device can be external or internal. If an external injection method is used, a supercapacitor energy storage system, a lithium battery energy storage converter, a dedicated disturbance injection module, or a frequency response testing device can be selected. If an internal injection method is used, any converter connected to the grid can be selected as the injection point.

[0049] Compared to the passive injection method of existing technologies, the active injection proposed in this invention can actively inject disturbance power into the system according to a preset frequency, amplitude, and waveform, thereby triggering a controlled response of the system. In this step, the injected power disturbance is directed to inject a signal of active power change with a certain frequency and amplitude into the system. The purpose is to induce a frequency shift, which is used to construct a frequency response model and extract the system inertia and damping.

[0050] Power disturbances clearly indicate the system's frequency dynamic response, allowing direct construction of frequency response function models. Modeling is permitted based on the differential relationship between disturbance power and frequency offset, supporting time-domain / frequency-domain analysis. Furthermore, disturbances can be designed as small disturbances or micro-disturbances that do not affect the stable operation of the main system.

[0051] Furthermore, the injected perturbation is frequency. Amplitude sinusoidal active power disturbance In a more preferred embodiment, to reduce the impact on the system, the disturbance amplitude... The total capacity of all converters can be selected. One ten-thousandth (i.e.) ), perturbation frequency It is necessary to avoid frequency ranges where the system may oscillate; for example, 0.2 Hz can be selected.

[0052] Step S220. Measure the frequency change at the grid connection point of the system after the injected power disturbance.

[0053] This step involves collecting data on the system frequency changes during the disturbance response process, providing data support for subsequent model parameter inversion. After a power disturbance is injected, the system frequency will experience transient changes. These frequency changes typically include information on the disturbance amplitude and phase; accurately extracting the frequency disturbance signal is a prerequisite for inertia / damping estimation.

[0054] Specifically, the measurement of frequency change involves the following steps:

[0055] Step S221. Measure the AC voltage at the system grid connection point.

[0056] Step S222. Use the zero-crossing detection method to obtain the current frequency of the system grid connection point based on the AC voltage.

[0057] Step S223. Perform harmonic analysis on the current frequency of the system's grid connection point to extract the frequency change.

[0058] After obtaining the AC voltage at the grid connection point of the converter station, calculating the system frequency using the zero-crossing detection method is a high-precision, low-delay frequency estimation method, particularly suitable for dynamic frequency response testing. This method is based on the zero-crossing time interval of the power frequency sine wave to estimate the current frequency and is suitable for relatively clean AC waveforms (such as the voltage on the low-voltage or high-voltage side of the main transformer). The system frequency disturbance signal is considered as a small variation contained above the fundamental frequency (e.g., 50 Hz), and specific disturbance frequency components, such as the amplitude and phase corresponding to the disturbance injection frequency, are extracted through harmonic analysis.

[0059] Furthermore, the system time-domain signal is represented using harmonic disturbances. Step S220 aims to extract the term corresponding to the power disturbance frequency. Then, the current frequency at the grid connection point is obtained using the zero-crossing detection method. Then, through Fourier decomposition, from frequency... Extract the frequency change corresponding to the power disturbance. , The magnitude of the frequency change. For the perturbation frequency, for and The phase difference.

[0060] Step S230. Based on the frequency response characteristics of the power system, calculate the equivalent inertia and equivalent damping of the system according to the frequency change at the grid connection point and the power value of the power disturbance.

[0061] This step involves constructing a frequency dynamic response model and, based on the measured power disturbance signal and frequency change signal, inverting to obtain the system's equivalent inertia and damping.

[0062] Specifically, step S220 determines the frequency change and the phase difference of the power disturbance at the grid connection point, and records the grid disturbance phase difference. A frequency dynamic response model of the system under the influence of the power disturbance is established. The frequency change and power disturbance at the grid connection point are substituted into the frequency dynamic response model, and the equivalent inertia and equivalent damping of the system are calculated based on the grid disturbance phase difference. Through the frequency dynamic response model, the inertia and damping can be solved through algebraic back-substitution of the amplitude-frequency characteristics or the phase difference and amplitude, simplifying the parameter identification process.

[0063] Furthermore, the frequency dynamic response model can be represented as follows:

[0064]

[0065] in, This indicates the power disturbance at a set frequency. This represents the sum of the capacities of all converters in the system. Represents the equivalent inertia. Indicates equivalent damping, This represents the frequency variation at the system's grid connection point. Indicates the system's rated frequency. Describes the differential operator. This indicates that the frequency change is differentiated.

[0066] Based on the aforementioned steps, the active power disturbance is... and frequency change Substituting back into the above model, we have the following deduction:

[0067]

[0068] The equivalent inertia of the system can be obtained by simplification. and equivalent damping as follows:

[0069]

[0070] Furthermore, the measurement method proposed in this invention can also be used to measure the inertia parameters and damping parameters of a single converter, specifically including the following measurement steps:

[0071] Step S241. Measure the power change and frequency change at a single converter port under the influence of power disturbance;

[0072] Step S242. Based on the frequency response characteristics of the power system, calculate the inertia parameters and damping parameters of a single converter according to the power change and frequency change at a single converter port.

[0073] Specifically, by measuring the voltage and current signals at the converter ports, the change in active power at a single converter x-port under the influence of disturbances is obtained. and frequency change ,in This represents the amplitude of the sinusoidal active power change at the converter port. The amplitude of the sinusoidal frequency change at the converter port. for and The phase difference between them, assuming the rated capacity of a single converter x is... Similar to the calculation of the equivalent inertia and equivalent damping of the above system, the inertia parameters and damping parameters of a single converter x are calculated as follows:

[0074]

[0075] The above embodiments provide a method for measuring the frequency response characteristic parameters of a power system, which can effectively achieve quantitative identification of system inertia and damping parameters. By actively injecting a sinusoidal power disturbance of a set frequency into the power system grid connection point, combined with high-precision extraction of system frequency changes, a parameter inversion method based on a frequency dynamic response model is established. This method can quantitatively calculate the equivalent inertia and equivalent damping of the system, improving the accuracy and engineering feasibility of frequency response characteristic modeling. In addition to the inertia and damping parameters of the overall system (such as at the substation level), this invention further supports the measurement of the power response behavior of a single converter port and the inversion of its own frequency response parameters, realizing the hierarchical quantification of frequency support capability. This helps to accurately evaluate the support role and control performance of each converter in the system. The injected disturbance signal has a fixed frequency and a settable amplitude, especially using... Using sinusoidal active power disturbances provides significant identification features in the system frequency response, facilitating high-precision measurements under normal operating conditions. This avoids reliance on large system disturbances or environmental noise, exhibiting good experimental repeatability and engineering adaptability. The method provided in this invention supports injecting disturbance signals through external disturbance injection devices or converters arbitrarily connected to the grid connection point, expanding the feasible methods for frequency response testing in different topologies (centralized / distributed access stations), adapting to various application scenarios, and facilitating practical deployment and online testing. Compared to offline evaluation methods that rely on fault disturbances, this invention achieves system response testing and parameter estimation under non-fault conditions through active disturbances, possessing the potential for online, periodic measurement and dynamic capability updates, providing efficient technical support for grid connection evaluation and dispatch access assessment of new energy power stations.

[0076] The disclosed method can be implemented using various types of devices. Therefore, the present invention also discloses an apparatus corresponding to the above method, and specific embodiments are given below for detailed description.

[0077] like Figure 3 As shown, one embodiment of the present invention provides a power system frequency response characteristic parameter measuring device, comprising:

[0078] The disturbance injection module 302 is used to actively inject a power disturbance of a set frequency into the system;

[0079] The frequency measurement module 304 is used to measure the frequency change at the grid connection point of the system after the injected power disturbance.

[0080] The parameter calculation module 306 is used to calculate the equivalent inertia and equivalent damping of the system based on the frequency response characteristics of the power system, according to the frequency change and power disturbance at the system grid connection point.

[0081] The device provided in this application embodiment has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0082] The methods and related apparatuses mentioned in the above embodiments are described with reference to the method flowcharts and / or structural diagrams provided in the embodiments of this application. Specifically, each block of the method flowchart and / or structural diagram, as well as combinations of 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, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, generate instructions for implementing the process. Figure 1 A schematic diagram of one or more processes and / or structures. Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 A schematic diagram of one or more processes and / or structures. Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 A process or multiple processes and / or structures illustrate the steps of the functions specified in one or more boxes.

[0083] The following embodiments illustrate the application of this method to a computer device. It is understood that the computer device can be any device with computing and processing capabilities, including but not limited to servers or personal laptops. In one embodiment, the computer device can be an application server, which can be a server used to run the application under test.

[0084] See Figure 4This document illustrates a hardware block diagram of an electronic device intended to represent various forms of digital computers, such as laptops, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframes, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present application described and / or claimed herein.

[0085] like Figure 4 As shown, the electronic device includes: at least one processor 1, at least one communication interface 2, at least one memory 3, and at least one communication bus 4;

[0086] In this embodiment of the application, the number of processor 1, communication interface 2, memory 3, and communication bus 4 is at least one, and processor 1, communication interface 2, and memory 3 communicate with each other through communication bus 4;

[0087] Processor 1 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0088] Memory 3 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk storage device;

[0089] The memory stores a program, which the processor can call. The program is used to implement the various processing steps of the aforementioned power system frequency response characteristic parameter measurement scheme.

[0090] This invention also provides a readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it implements various processing flows of the power system frequency response characteristic parameter measurement scheme provided in any possible implementation of the above embodiments and / or in combination with the embodiments.

[0091] The invention has been described in particular detail above with respect to possible scenarios, and those skilled in the art will recognize that the invention can be practiced through other embodiments. Specific naming of components, capitalization of terms, attributes, data structures, or any other programming or structural aspects are not mandatory or important, and the mechanisms or features of implementing the invention may have different names, forms, or procedures. The system can be implemented through a combination of hardware and software (as described), entirely through hardware elements, or entirely through software elements. The specific division of functions among the various system components described herein is merely exemplary and not mandatory; rather, the functions performed by a single system component can be performed by multiple components, or the functions performed by multiple components can be performed by a single component.

[0092] Those skilled in the art should understand that the various steps of the disclosed methods can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using device-executable program code, which can then be stored in a storage device for execution by the computing device. Alternatively, they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Therefore, the embodiments disclosed in this invention are not limited to any specific hardware and software combination.

[0093] The programs (also referred to as programs, software, software applications, or code) executable by these computing devices include machine instructions of a programmable processor and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms “machine-readable medium” and “computer-readable medium” refer to any computer program product, device, and / or apparatus (e.g., disk, optical disk, memory, programmable logic device (PLD)) used to provide machine instructions and / or data to a programmable processor, including machine-readable media that receive machine instructions as machine-readable signals. The term “machine-readable signal” refers to any signal used to provide machine instructions and / or data to a programmable processor.

[0094] Certain aspects of this invention include the process steps and instructions described herein in algorithmic form. It should be noted that the process steps and instructions of this invention can be implemented in software, firmware, and / or hardware, and when implemented in software, they can be downloaded, stored on various operating systems and operated from said platforms.

[0095] Those skilled in the art will understand that the structures shown in the figures are merely block diagrams of some structures related to the present application and do not constitute a limitation on the terminal device to which the present application is applied. Specific terminal devices may include more or fewer components than those shown in the figures, or combine certain components, or have different component arrangements.

[0096] In the description of this specification, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "possible design," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0097] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the frequency response characteristic parameters of a power system, characterized in that, include: Actively inject power disturbances of a set frequency into the system; Measure the frequency change at the grid connection point of the system after the injected power disturbance; Based on the frequency response characteristics of the power system, the equivalent inertia and equivalent damping of the system are calculated according to the frequency change and power disturbance at the grid connection point of the system.

2. The method according to claim 1, characterized in that, The method further includes: Measure the power and frequency changes at a single converter port under the influence of power disturbances; Based on the frequency response characteristics of the power system, the inertia parameters and damping parameters of a single converter are calculated according to the power change and frequency change at a single converter port.

3. The method according to claim 1 or 2, characterized in that, The power disturbance injected into the system at a set frequency includes: A power disturbance of a set frequency is actively injected into the system grid connection point through an external disturbance injection device.

4. The method according to claim 1 or 2, characterized in that, The power disturbance injected into the system at a set frequency includes: Control any converter at the grid connection point of the system to actively inject a power disturbance of a set frequency into the grid connection point.

5. The method according to claim 1, characterized in that, The measured frequency change at the grid connection point of the system after the power disturbance is injected includes: Measure the AC voltage at the grid connection point of the system after the injected power disturbance; The current frequency of the system's grid connection point is obtained based on the AC voltage using the zero-crossing detection method. The frequency change is obtained by performing harmonic analysis on the current frequency of the system's grid connection point.

6. The method according to claim 1, characterized in that, The calculation of the equivalent inertia and equivalent damping of the system based on the frequency response characteristics of the power system, according to the frequency change and power disturbance at the grid connection point, includes: Determine the frequency variation and the phase difference of the power disturbance at the grid connection point of the system, and denote the grid connection disturbance phase difference; A frequency dynamic response model of the system under the influence of the power disturbance is established; Substitute the frequency change and power disturbance at the grid connection point of the system into the frequency dynamic response model, and calculate the equivalent inertia and equivalent damping of the system based on the phase difference of the grid connection disturbance according to the frequency dynamic response model.

7. The method according to claim 6, characterized in that, The frequency dynamic response model is represented as follows: ， in, This indicates the power disturbance at a set frequency. This represents the sum of the capacities of all converters in the system. Represents the equivalent inertia. Indicates equivalent damping, This represents the frequency variation at the system's grid connection point. Indicates the system's rated frequency. Describes the differential operator. This indicates that the frequency change is differentiated.

8. A device for measuring the frequency response characteristic parameters of a power system, characterized in that, include: The disturbance injection module is used to actively inject power disturbances of a set frequency into the system; The frequency measurement module is used to measure the frequency change at the grid connection point of the system after the injected power disturbance. The parameter calculation module is used to calculate the equivalent inertia and equivalent damping of the power system based on the frequency response characteristics of the power system, according to the frequency change and power disturbance at the grid connection point.

9. An electronic device, characterized in that, It includes a memory storing computer-executable instructions and a processor, which, when executed by the processor, causes the device to perform the power system frequency response characteristic parameter measurement method as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, It contains a computer-executable program that, when executed, enables the measurement method for power system frequency response characteristic parameters as described in any one of claims 1 to 7.

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