Frequency coupling characteristics calculation method, device, equipment, storage medium and product

Abstract

The present application discloses a method, apparatus, device, storage medium, and product for calculating frequency coupling characteristics, and relates to the technical field of frequency coupling characteristic analysis, including: injecting a positive-sequence disturbance signal and a negative-sequence disturbance signal into a power generation device under test, respectively, to obtain a positive-sequence disturbance response signal and a negative-sequence disturbance response signal at the port of the power generation device under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent DIBS signals; performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal, respectively, to obtain corresponding voltage signal components and current signal components; performing phase sequence separation on the voltage signal components and the current signal components, respectively, to obtain voltage signal phase sequence components and current signal phase sequence components; and calculating a frequency coupling admittance matrix based on the voltage signal phase sequence components and the current signal phase sequence components to obtain a frequency coupling characteristic calculation result. The present application can improve the efficiency and accuracy of frequency coupling characteristic calculation.

Description

Technical Field

[0001] The present application relates to the technical field of frequency coupling characteristic analysis, and in particular to a method, apparatus, device, storage medium, and product for calculating frequency coupling characteristics. Background Art

[0002] In related art, when measuring the impedance-frequency coupling characteristics of a power generation device, a single sinusoidal signal or multiple sinusoidal signals is mainly injected into the device under test to perform response analysis to calculate the impedance-frequency coupling characteristics of the device under test.

[0003] While a single sinusoidal signal has a high signal-to-noise ratio, its measurement efficiency is slow and it struggles to quickly cover a wide frequency range. While a multi-sinusoidal signal can simultaneously inject a large number of harmonic components, it can easily produce excessively high peak values, posing a risk of interfering with the steady-state operation of the equipment. Therefore, the aforementioned impedance-frequency coupling characteristic calculation method suffers from shortcomings in measurement efficiency and signal interference, making it impossible to accurately and efficiently measure the frequency-coupled impedance characteristics of power generation equipment, which in turn affects the assessment and analysis of its grid-connected stability. Summary of the Invention

[0004] The main purpose of this application is to provide a method, device, equipment, storage medium and product for calculating frequency coupling characteristics, aiming to solve the technical problem of low efficiency and accuracy in frequency coupling characteristic measurement.

[0005] To achieve the above objectives, the present application proposes a method for calculating frequency coupling characteristics, which includes:

[0006] Injecting a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test, respectively, to obtain a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include a three-phase voltage signal and a three-phase current signal of the port of the power generation equipment under test;

[0007] Perform Fourier analysis on the positive sequence disturbance response signal and the negative sequence disturbance response signal respectively to obtain the corresponding voltage signal components and current signal components;

[0008] Separating the voltage signal component and the current signal component in phase sequence to obtain the voltage signal phase sequence component and the current signal phase sequence component;

[0009] Based on the phase sequence components of the voltage signal and the current signal, the frequency coupling admittance matrix is ​​calculated to obtain the frequency coupling characteristic calculation results.

[0010] In one embodiment, the steps of injecting a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test, and obtaining a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of a port of the power generation equipment under test include:

[0011] Injecting a positive-sequence disturbance signal into the A-phase input terminal of the power generation equipment under test, and injecting an inverted signal of the positive-sequence disturbance signal into the B-phase input terminal of the power generation equipment under test, to obtain a positive-sequence disturbance response signal of the port of the power generation equipment under test;

[0012] A negative-sequence disturbance signal is injected into the A-phase input terminal of the power generation equipment under test, and an inverted signal of the negative-sequence disturbance signal is injected into the B-phase input terminal of the power generation equipment under test to obtain a negative-sequence disturbance response signal of the port of the power generation equipment under test.

[0013] In one embodiment, the positive sequence disturbance signal corresponds to a plurality of first preset signal frequencies, the amplitude of the positive sequence disturbance signal at each first preset signal frequency is a preset signal amplitude and is not 0, and the amplitude of the positive sequence disturbance signal at frequencies other than the first preset signal frequency is 0;

[0014] The negative-sequence disturbance signal corresponds to multiple second preset signal frequencies, the amplitude of the negative-sequence disturbance signal at each second preset signal frequency is the preset signal amplitude and is not 0, and the amplitude of the negative-sequence disturbance signal at non-second preset signal frequencies is 0; the second preset signal frequency = the first preset signal frequency - 2× the base frequency.

[0015] In one embodiment, the steps of performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal to obtain corresponding voltage signal components and current signal components include:

[0016] Sampling the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively according to a preset signal length to obtain a first sampling signal corresponding to the positive-sequence disturbance response signal and a second sampling signal corresponding to the negative-sequence disturbance response signal;

[0017] Extracting, by Fourier analysis, a first positive-sequence disturbance voltage signal component and a first positive-sequence disturbance current signal component of the first sampling signal at a first preset signal frequency, and a second positive-sequence disturbance voltage signal component and a second positive-sequence disturbance current signal component of the first sampling signal at a second preset signal frequency;

[0018] By Fourier analysis, a first negative-sequence disturbance voltage signal component and a first negative-sequence disturbance current signal component of the second sampling signal at a first preset signal frequency, as well as a second negative-sequence disturbance voltage signal component and a second negative-sequence disturbance current signal component of the second sampling signal at a second preset signal frequency are extracted.

[0019] In one embodiment, the steps of performing phase sequence separation on the voltage signal component and the current signal component to obtain the voltage signal phase sequence component and the current signal phase sequence component include:

[0020] Separating the voltage signal component and the current signal component in phase sequence to obtain a phase sequence separation signal;

[0021] When the second preset signal frequency is less than 0, performing positive sequence extraction on the phase sequence separation signal at the first preset signal frequency and the second preset signal frequency respectively to obtain a voltage positive sequence component and a current positive sequence component;

[0022] When the second preset signal frequency is greater than 0, positive sequence extraction is performed on the phase sequence separation signal at the first preset signal frequency to obtain the voltage positive sequence component and the current positive sequence component, and negative sequence extraction is performed on the phase sequence separation signal at the second preset signal frequency to obtain the voltage negative sequence component and the current negative sequence component.

[0023] In one embodiment, the frequency coupling admittance matrix is ​​calculated as: ;in, is the frequency coupling admittance matrix, 、 、 、 are four sub-admittance elements, is the phase sequence component of the current signal at the first preset signal frequency corresponding to the positive sequence disturbance response signal, is the phase sequence component of the voltage signal at the first preset signal frequency corresponding to the positive sequence disturbance response signal, is the current signal phase sequence component at the second preset signal frequency corresponding to the positive sequence disturbance response signal, is the phase sequence component of the voltage signal at the second preset signal frequency corresponding to the positive sequence disturbance response signal, is the phase sequence component of the current signal at the first preset signal frequency corresponding to the negative sequence disturbance response signal, is the phase sequence component of the voltage signal at the first preset signal frequency corresponding to the negative sequence disturbance response signal, is the phase sequence component of the current signal at the second preset signal frequency corresponding to the negative sequence disturbance response signal, It is the phase sequence component of the voltage signal at the second preset signal frequency corresponding to the negative-sequence disturbance response signal.

[0024] In addition, to achieve the above-mentioned purpose, the present application also proposes a frequency coupling characteristic calculation device, which includes:

[0025] A disturbance injection module is used to inject a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test, respectively, to obtain a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include a three-phase voltage signal and a three-phase current signal of the port of the power generation equipment under test;

[0026] A Fourier analysis module is used to perform Fourier analysis on the positive sequence disturbance response signal and the negative sequence disturbance response signal to obtain corresponding voltage signal components and current signal components;

[0027] A phase sequence separation module is used to perform phase sequence separation on the voltage signal component and the current signal component respectively to obtain the voltage signal phase sequence component and the current signal phase sequence component;

[0028] The characteristic calculation module is used to calculate the frequency coupling admittance matrix based on the phase sequence component of the voltage signal and the phase sequence component of the current signal to obtain the frequency coupling characteristic calculation result.

[0029] In addition, to achieve the above-mentioned purpose, the present application also proposes a frequency coupling characteristic calculation device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the frequency coupling characteristic calculation method as described above.

[0030] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium and stores a computer program. When the computer program is executed by a processor, the steps of the frequency coupling characteristic calculation method as described above are implemented.

[0031] In addition, to achieve the above-mentioned purpose, the present application also proposes a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps of the frequency coupling characteristic calculation method as described above are implemented.

[0032] One or more technical solutions proposed in this application have at least the following technical effects:

[0033] In the frequency coupling characteristic calculation method proposed in the present application, two sets of linearly independent discrete interval binary sequence signals can be injected into the power generation equipment under test as positive-sequence disturbance signals and negative-sequence disturbance signals, respectively, to obtain the positive-sequence disturbance response signal and negative-sequence disturbance response signal of the port of the power generation equipment under test after the disturbance injection; thereby, the positive-sequence disturbance response signal and the negative-sequence disturbance response signal can be subjected to Fourier analysis and phase sequence separation respectively to obtain the phase sequence component of the voltage signal and the phase sequence component of the current signal; then, the frequency coupling admittance matrix of the phase sequence component of the voltage signal and the phase sequence component of the current signal can be calculated to obtain the frequency coupling characteristic calculation result.

[0034] This application uses two sets of linearly independent discrete interval binary sequence signals (DIBS: Discrete Interval Binary Sequence) as positive-sequence disturbance signals and negative-sequence disturbance signals to input into the power generation equipment under test to calculate the frequency coupling characteristics. The DIBS signal can contain multiple frequency components in one injection, and these components can simultaneously excite the response of the system. Through Fourier analysis, the signals corresponding to multiple frequency components can be extracted at the same time, thereby significantly improving the measurement efficiency. Compared with a single sinusoidal signal, the DIBS signal can cover a wider frequency range in a shorter time, reducing measurement time and resource consumption; at the same time, the DIBS signal has a lower peak characteristic, and compared with multi-sinusoidal signals, it can avoid interference with the steady-state operation of the equipment under test due to excessively high signal peaks; thereby effectively improving the calculation efficiency and accuracy of the frequency coupling characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] Figure 1 A flow chart illustrating a method for calculating frequency coupling characteristics according to the present invention;

[0038] Figure 2 This is a detailed flowchart of step S200;

[0039] Figure 3 This is a detailed flowchart of step S300;

[0040] Figure 4 is a circuit diagram of an exemplary impedance measurement system;

[0041] Figure 5 A schematic diagram of a simplified flow chart of a method for calculating frequency coupling characteristics provided in Example 1 of the present application;

[0042] Figure 6 is a time domain waveform of a first set of DIBS signals as an example;

[0043] Figure 7 is an example of an amplitude-frequency characteristic curve of a first group of DIBS signals;

[0044] Figure 8 is a schematic diagram of an impedance measurement result of an example;

[0045] Figure 9 This is a schematic diagram of the module structure of the frequency coupling characteristics calculation device according to an embodiment of the present application;

[0046] Figure 10 Schematic diagram of the device structure of the hardware operating environment involved in the frequency coupling characteristic calculation method in the embodiment of the present application.

[0047] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present application and are not intended to limit the present application.

[0049] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0050] The main solution of the embodiment of the present application is: injecting a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test respectively, and obtaining a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two groups of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include a three-phase voltage signal and a three-phase current signal of the port of the power generation equipment under test; performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively, and obtaining corresponding voltage signal components and current signal components; performing phase sequence separation on the voltage signal components and the current signal components respectively, and obtaining voltage signal phase sequence components and current signal phase sequence components; calculating the frequency coupling admittance matrix based on the voltage signal phase sequence components and the current signal phase sequence components, and obtaining the frequency coupling characteristic calculation results.

[0051] The impedance model of a renewable energy power generation device can reflect its oscillation stability when connected to the power grid, so obtaining its impedance model is of great significance for testing its grid-connected performance. Impedance measurement is a common method for obtaining impedance models in actual engineering and laboratory testing. Generally, the impedance can be calculated by injecting a small disturbance signal at a specific frequency and extracting its port response signal. The impedance of renewable energy power generation equipment can generally be characterized as two single-input single-output (SISO) impedance models with positive and negative sequence decoupling. Related technologies have proposed the use of disturbance signal injection methods such as single sine sweep, binary sequence signal, and multi-sinusoidal signal for SISO impedance measurement. Related research has shown that renewable energy power generation equipment based on power electronics technology usually exhibits a frequency coupling effect; the frequency coupling effect is mainly manifested in the generation of a coupling frequency component that differs from the fundamental frequency by twice the disturbance frequency. Therefore, in order to transform the impedance model from SISO to multiple-input multiple-output (MIMO), it is necessary to use a two-dimensional admittance matrix to represent it.

[0052] In order to ensure the reliability of the grid-connected stability analysis of power generation equipment, the frequency coupling effect needs to be considered. In the related art, a pseudo-random binary sequence signal can be used for disturbance input, but due to its weak design capability for its own spectrum characteristics, it is difficult to ensure the linear independence of the disturbance signal injection and the accuracy of the analysis results; in the related art, when measuring the impedance frequency coupling characteristics of power generation equipment, a single sinusoidal signal or multiple sinusoidal signals is mainly injected into the device under test for response analysis to calculate the impedance frequency coupling characteristics of the device under test. Among them, although a single sinusoidal signal has a high signal-to-noise ratio, its measurement efficiency is slow and it is difficult to quickly cover a wide frequency range; and although a multi-sinusoidal signal can inject a large number of harmonic components at a time, it is easy for the peak value to be too high, and there is a risk of interfering with the steady-state operation of the equipment.

[0053] Therefore, the above-mentioned impedance frequency coupling characteristic calculation method has shortcomings in measurement efficiency and signal interference. It is unable to accurately and efficiently measure the frequency coupling impedance characteristics of power generation equipment, which in turn affects the stability assessment and analysis of its grid connection. Therefore, it is necessary to seek a better frequency coupling characteristic calculation method to improve the shortcomings in related technologies.

[0054] The present application provides a solution that can use two sets of linearly independent discrete interval binary sequence signals (DIBS: Discrete Interval Binary Sequence) as positive-sequence disturbance signals and negative-sequence disturbance signals to input into the power generation equipment under test for frequency coupling characteristic calculation. The DIBS signal can contain multiple frequency components in one injection, and these components can simultaneously excite the response of the system. Through Fourier analysis, multiple frequency component signals can be extracted at the same time, thereby significantly improving the measurement efficiency. Compared with a single sinusoidal signal, the DIBS signal can cover a wider frequency range in a shorter time, reducing measurement time and resource consumption; at the same time, the DIBS signal has a lower peak characteristic, and compared with multi-sinusoidal signals, it can also avoid interference with the steady-state operation of the equipment under test due to excessively high signal peaks, and can improve the calculation efficiency and accuracy of the frequency coupling characteristics.

[0055] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication, and program execution functions, such as a personal computer, or an electronic device capable of implementing the above functions. This embodiment and the following embodiments are described below using a frequency coupling characteristic calculation device as an example.

[0056] Based on this, the embodiment of the present application provides a method for calculating frequency coupling characteristics, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the method for calculating frequency coupling characteristics of the present application.

[0057] In this embodiment, the frequency coupling characteristic calculation method includes steps S100 to S400:

[0058] Step S100 : injecting a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test respectively, and obtaining a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of a port of the power generation equipment under test.

[0059] Among them, the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include the port three-phase voltage signal and the port three-phase current signal of the tested power generation equipment.

[0060] Specifically, the positive-sequence disturbance signal is mainly used to stimulate the positive-sequence response of the power generation equipment under test and obtain the positive-sequence disturbance response signal. Injecting the positive-sequence disturbance signal helps to simulate the response of the power generation equipment under test in an ideal working environment. The characteristics of the positive-sequence disturbance signal are that its frequency characteristics and phase sequence match the normal operation of the power generation equipment; while the negative-sequence disturbance signal is used to stimulate the positive-sequence response of the power generation equipment under test and obtain the negative-sequence disturbance response signal. Injecting the negative-sequence disturbance signal into the power generation equipment under test can simulate the abnormal behavior of the equipment or the load imbalance state; by injecting the positive-sequence disturbance signal and the negative-sequence disturbance signal into the power generation equipment under test respectively, the frequency coupling characteristics of the power generation equipment can be comprehensively analyzed. The above-mentioned positive-sequence disturbance signal and negative-sequence disturbance signal can be set as two sets of linearly independent DIBS signals. The linearly independent design of the positive-sequence disturbance signal and the negative-sequence disturbance signal can ensure their independence in subsequent signal processing, avoid mutual interference, and affect the accuracy of the subsequent frequency coupling characteristic calculation.

[0061] In a feasible embodiment, the positive-sequence disturbance signal may correspond to multiple first preset signal frequencies, the amplitude of the positive-sequence disturbance signal at each first preset signal frequency is the preset signal amplitude and is not 0, and the amplitude of the positive-sequence disturbance signal at frequencies other than the first preset signal frequency is 0; the negative-sequence disturbance signal corresponds to multiple second preset signal frequencies, the amplitude of the negative-sequence disturbance signal at each second preset signal frequency is the preset signal amplitude and is not 0, and the amplitude of the negative-sequence disturbance signal at frequencies other than the second preset signal frequency is 0; the second preset signal frequency = the first preset signal frequency - 2 × the base frequency.

[0062] For example, the base frequency and multiple measurement frequencies (i.e., first preset signal frequencies) can be predetermined according to the test requirements of the power generation equipment. The set of first preset signal frequencies can be regarded as , the fundamental frequency can be written as , the second preset signal frequency corresponds to ; That is, the frequency of the positive sequence disturbance signal is , the frequency of the negative sequence disturbance signal is , there is no linear relationship between the two. In practical applications, the DIBS signal can be set to obtain the positive-sequence disturbance signal and the negative-sequence disturbance signal mentioned above: the frequency component where the disturbance amplitude of the DIBS signal is mainly distributed is defined as the set frequency; the DIBS signal can contain multiple frequency components in one injection, that is, there are multiple set frequencies of the DIBS signal. When designing the positive-sequence disturbance signal, the set frequency of the DIBS signal is set to multiple first preset signal frequencies determined according to the design requirements. , the amplitude corresponding to each first preset signal frequency can be set to a uniform value (i.e., the preset signal amplitude) according to actual needs, and then the amplitudes at the remaining frequencies (not the first preset signal frequency) are set to 0, thereby obtaining a set of DIBS signals corresponding to the positive sequence disturbance; similarly, when designing the negative sequence disturbance signal, the setting frequency of the DIBS is set to the second preset signal frequency ( ), the amplitude corresponding to each second preset signal frequency is consistent with the preset signal amplitude when the positive-sequence disturbance signal is designed, and then the amplitudes at the remaining frequencies (non-second preset signal frequencies) are set to 0 to obtain a set of DIBS signals corresponding to the negative-sequence disturbance; based on the above design, two sets of linearly independent DIBS signals can be obtained as the positive-sequence disturbance signal and negative-sequence disturbance signal of the device under test.

[0063] After the positive-sequence and negative-sequence disturbance signals obtained through the DIBS design are respectively input into the power generation equipment under test, the positive-sequence and negative-sequence disturbance response signals at the power generation equipment's ports can be obtained for subsequent analysis. It should be noted that the power generation equipment's ports are generally those connected to the frequency coupling characteristic calculation device. The positive-sequence disturbance response signals at the power generation equipment's ports are the three-phase voltage and current signals actually measured at the power generation equipment's ports after the aforementioned positive-sequence disturbance signal is injected. The negative-sequence disturbance response signals are the three-phase voltage and current signals actually measured at the power generation equipment's ports after the aforementioned negative-sequence disturbance signal is injected. The DIBS signal design method enables the configuration of disturbance parameters for two sets of linearly independent disturbance signals. Furthermore, the two signal injections (i.e., the first injection of the positive-sequence disturbance signal and the second injection of the negative-sequence disturbance signal) comprehensively cover the positive- and negative-sequence responses across a wide frequency range, enabling broadband impedance identification.

[0064] It is worth mentioning that when injecting positive-sequence disturbance signals and negative-sequence disturbance signals into the power generation equipment under test respectively, in order to avoid introducing zero-sequence components and affecting the accuracy of the measurement results; in a feasible implementation manner, step S100 may specifically include: injecting a positive-sequence disturbance signal into the A-phase input terminal of the power generation equipment under test, and injecting an inverted signal of the positive-sequence disturbance signal into the B-phase input terminal of the power generation equipment under test, to obtain a positive-sequence disturbance response signal of the port of the power generation equipment under test; injecting a negative-sequence disturbance signal into the A-phase input terminal of the power generation equipment under test, and injecting an inverted signal of the negative-sequence disturbance signal into the B-phase input terminal of the power generation equipment under test, to obtain a negative-sequence disturbance response signal of the port of the power generation equipment under test.

[0065] That is, when injecting the disturbance signal, the disturbance signals with opposite phases can be injected into the A and B phases of the power generation equipment under test to ensure that the injected signals do not generate zero-sequence components; for example, the positive-sequence disturbance signal is expressed as , the negative sequence disturbance signal is expressed as When injecting disturbance signals, the first time is to inject the disturbance signals into the A and B phases of the generator under test. and , in order to obtain the positive sequence disturbance response signal of the power generation equipment under test; then in the second injection, the A phase and B phase of the power generation equipment under test are injected respectively and , to obtain the negative-sequence disturbance response signal of the port of the tested power generation equipment; by reducing the zero-sequence component, the subsequent signal processing process can be simplified to a certain extent, and the noise interference caused by the zero-sequence component can also be avoided, thereby ensuring the accuracy of the signal response and subsequent analysis.

[0066] Step S200 , performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively to obtain corresponding voltage signal components and current signal components.

[0067] Step S300 , performing phase sequence separation on the voltage signal component and the current signal component respectively to obtain a voltage signal phase sequence component and a current signal phase sequence component.

[0068] Specifically, after obtaining the positive-sequence disturbance response signal and the negative-sequence disturbance response signal of the port of the tested power generation equipment, the three-phase voltage signal and the three-phase current signal of the port under the positive-sequence disturbance, as well as the three-phase voltage signal and the three-phase current signal of the port under the negative-sequence disturbance of the tested power generation equipment can be subjected to Fourier analysis respectively; through Fourier transform, the signal in the time domain dimension can be converted into a frequency domain signal, and the result after Fourier analysis can include the amplitude of the signal at different frequencies, so as to better analyze and identify the frequency components in the response signal. Therefore, by performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively, the frequency components of the voltage signal and the current signal corresponding to the positive / negative-sequence disturbance response signal (i.e., the voltage signal component and the current signal component) can be obtained respectively. In a feasible embodiment, step S200 can specifically include steps S210~S230, such as Figure 2 As shown, Figure 2 This is a detailed flowchart of step S200.

[0069] Step S210 , sampling the positive-sequence disturbance response signal and the negative-sequence disturbance response signal according to a preset signal length to obtain a first sampling signal corresponding to the positive-sequence disturbance response signal and a second sampling signal corresponding to the negative-sequence disturbance response signal.

[0070] Step S220: Extracting a first positive-sequence disturbance voltage signal component and a first positive-sequence disturbance current signal component of the first sampling signal at a first preset signal frequency, and a second positive-sequence disturbance voltage signal component and a second positive-sequence disturbance current signal component of the first sampling signal at a second preset signal frequency through Fourier analysis.

[0071] Step S230: Extracting, by Fourier analysis, a first negative-sequence disturbance voltage signal component and a first negative-sequence disturbance current signal component of the second sampling signal at a first preset signal frequency, and a second negative-sequence disturbance voltage signal component and a second negative-sequence disturbance current signal component of the second sampling signal at a second preset signal frequency.

[0072] Specifically, a preset signal length (such as 1s) can be determined according to actual test requirements, and the positive-sequence disturbance response signal and the negative-sequence disturbance response signal are sampled and processed according to the preset signal length to obtain a first sampling signal and a second sampling signal; then, the components of the first sampling signal at the first preset signal frequency (the first positive-sequence disturbance voltage signal component and the first positive-sequence disturbance current signal component) and the components at the second preset signal frequency (the second positive-sequence disturbance voltage signal component and the second positive-sequence disturbance current signal component) are extracted by Fourier analysis; similarly, the components of the second sampling signal at the first preset signal frequency (the first negative-sequence disturbance voltage signal component and the first negative-sequence disturbance current signal component) and the components at the second preset signal frequency (the second negative-sequence disturbance voltage signal component and the second negative-sequence disturbance current signal component) are extracted by Fourier analysis.

[0073] It should be noted that the first sampling signal corresponds to the positive-sequence disturbance of the equipment. As can be seen from the above content, when designing the injection of the positive-sequence disturbance signal, although the disturbance amplitude is only set for the signal at the set frequency (first preset signal frequency), since the DIBS signal cannot achieve accurate design of the desired spectral characteristics, there may also be a weaker disturbance amplitude at the non-set frequency (second preset signal frequency); therefore, in order to consider the clutter interference at the non-set frequency and to achieve accurate measurement of the frequency coupling impedance, when Fourier analysis is performed on the first sampling signal, the components at the corresponding set frequency and non-set frequency need to be extracted; in the extraction of the first sampling signal corresponding to the positive-sequence disturbance, the component extracted at the first preset signal frequency is the set frequency component, and the component extracted at the second preset signal frequency is regarded as the clutter component, and then the clutter component and the set frequency component are regarded together as the disturbance signal actually injected into the power generation equipment under test for frequency coupling characteristic analysis and calculation.

[0074] Similarly, the second sampling signal corresponds to the device's negative-sequence disturbance. While the disturbance amplitude is set only for the signal at the set frequency (the second preset signal frequency) during the negative-sequence disturbance signal injection design, weaker disturbance amplitudes may also exist at non-set frequencies (the first preset signal frequency). Therefore, when performing Fourier analysis on the second sampling signal, the components at both the set and non-set frequencies must be extracted. When extracting the second sampling signal corresponding to the negative-sequence disturbance, the component extracted at the second preset signal frequency is considered the set frequency component, while the component extracted at the first preset signal frequency is considered the clutter component. It should be noted that because the amplitude of the clutter component is significantly smaller than the amplitude of the set frequency component, this clutter component extraction still ensures linear independence between the two injections of the positive-sequence disturbance signal and the negative-sequence disturbance signal.

[0075] After obtaining the voltage signal component and the current signal component, phase sequence separation is required to separate the positive phase sequence and the negative phase sequence of the component so as to perform subsequent accurate analysis. In a feasible embodiment, step S300 may specifically include steps S310 to S330, such as Figure 3 As shown, Figure 3 This is a detailed flowchart of step S300.

[0076] Step S310 , performing phase sequence separation on the voltage signal component and the current signal component respectively to obtain a phase sequence separation signal.

[0077] Step S320 , when the second preset signal frequency is less than 0, performing positive sequence extraction on the phase sequence separation signal at the first preset signal frequency and the second preset signal frequency respectively to obtain a voltage positive sequence component and a current positive sequence component.

[0078] Step S330, when the second preset signal frequency is greater than 0, the phase sequence separation signal is subjected to positive sequence extraction at the first preset signal frequency to obtain the voltage positive sequence component and the current positive sequence component, and the phase sequence separation signal is subjected to negative sequence extraction at the second preset signal frequency to obtain the voltage negative sequence component and the current negative sequence component.

[0079] Specifically, the voltage signal component and current signal component extracted by Fourier analysis can be separated and processed according to their phase sequence characteristics (positive sequence, negative sequence) to obtain corresponding phase sequence separation signals; the phase sequence separation signal includes a phase sequence separation signal of the voltage signal component and a phase sequence separation signal of the current signal component. If the second preset signal frequency is less than 0, the positive sequence components at the first preset signal frequency and the second preset signal frequency in the phase sequence separation signal are correspondingly extracted to obtain the voltage positive sequence component and the current positive sequence component; if the second preset signal frequency is greater than 0, the positive sequence components at the first preset signal frequency in the phase sequence separation signal are correspondingly extracted to obtain the voltage positive sequence component and the current positive sequence component, and the negative sequence components at the second preset signal frequency in the phase sequence separation signal are correspondingly extracted to obtain the voltage negative sequence component and the current negative sequence component.

[0080] Step S400 , calculating a frequency coupling admittance matrix based on the phase sequence component of the voltage signal and the phase sequence component of the current signal to obtain a calculation result of a frequency coupling characteristic.

[0081] Specifically, the frequency coupling admittance matrix is ​​a tool that can describe the coupling relationship between the voltage and current of a device at different frequencies. Based on the extracted phase sequence components of the voltage and current signals, the frequency coupling admittance matrix can be calculated to obtain the coupling characteristics of the power generation device under test at different frequencies. As a feasible implementation method, the calculation formula for the above frequency coupling admittance matrix is: ;in, is the frequency coupling admittance matrix, 、 、 、 are four sub-admittance elements, is the phase sequence component of the current signal at the first preset signal frequency corresponding to the positive sequence disturbance response signal, is the phase sequence component of the voltage signal at the first preset signal frequency corresponding to the positive sequence disturbance response signal, is the current signal phase sequence component at the second preset signal frequency corresponding to the positive sequence disturbance response signal, is the phase sequence component of the voltage signal at the second preset signal frequency corresponding to the positive sequence disturbance response signal, is the phase sequence component of the current signal at the first preset signal frequency corresponding to the negative sequence disturbance response signal, is the phase sequence component of the voltage signal at the first preset signal frequency corresponding to the negative sequence disturbance response signal, is the phase sequence component of the current signal at the second preset signal frequency corresponding to the negative sequence disturbance response signal, It is the phase sequence component of the voltage signal at the second preset signal frequency corresponding to the negative-sequence disturbance response signal.

[0082] Substituting the extracted phase-sequence components of the voltage signal and the current signal into the above formula, the frequency-coupled admittance matrix corresponding to the tested power generation equipment can be calculated. This frequency-coupled admittance matrix reflects the response characteristics of the power generation equipment at different frequencies. These characteristics can reveal the equipment performance and comprehensively evaluate the operating stability of the power generation equipment.

[0083] It can be understood that the frequency coupling characteristic calculation method provided in the embodiment of the present application adopts two sets of linearly independent discrete interval binary sequence signals (DIBS: Discrete Interval Binary Sequence) as positive-sequence disturbance signals and negative-sequence disturbance signals to input into the power generation equipment under test for frequency coupling characteristic calculation. The DIBS signal can contain multiple frequency components in one injection, and these components can simultaneously excite the response of the system. Through Fourier analysis, multiple frequency component signals can be extracted at the same time, thereby significantly improving the measurement efficiency. Compared with a single sinusoidal signal, the DIBS signal can cover a wider frequency range in a shorter time, reducing measurement time and resource consumption; at the same time, the DIBS signal has a lower peak characteristic, and compared with multi-sinusoidal signals, it can also avoid interference with the steady-state operation of the equipment under test due to excessively high signal peaks, and can improve the calculation efficiency and accuracy of the frequency coupling characteristics.

[0084] For example, in order to help understand the implementation process of the frequency coupling characteristic calculation method obtained by combining this embodiment with the above embodiment 1, please refer to Figures 4 and 5 . Figure 4 This is an example of an impedance measurement system circuit diagram; the frequency coupling characteristic calculation method of this application is mainly based on the following Figure 4 The impedance measurement system shown is implemented as Figure 4 As shown in the figure, the impedance measurement system includes a power grid, a disturbance voltage source and a main circuit of the device under test connected in sequence; the designed DIBS signal can be injected into the main circuit of the device under test in series through the disturbance voltage source; after each disturbance injection, the three-phase voltage can be collected from the port of the device under test and three-phase current ; And perform fast Fourier transform (FFT) and phase sequence separation on the three-phase voltage and three-phase current to obtain the voltage components at different measurement frequencies f and current components ; Then calculate the frequency coupling admittance matrix based on the extracted related components. Based on the above impedance measurement system, Figure 5 A brief flowchart of an exemplary method for calculating frequency coupling characteristics is provided, specifically:

[0085] In this example, a grid-connected inverter (GCI) is used as the measurement object to perform the frequency coupling characteristic calculation method described above. The GCI parameters are shown in Table 1 below.

[0086] Table 1 GCI parameters

[0087]

[0088] like Figure 5 As shown in , when calculating the frequency coupling characteristics, the frequency and amplitude configuration of two sets of linearly independent DIBS signals can be performed first; wherein, the measurement frequency of the frequency coupling impedance is selected according to actual needs. In this example, the measurement frequency is determined to be [1, 2, 3, 4, 5, 7, 10, 13, 16, 21, 26, 34, 43, 55, 62, 70, 89,114, 144, 183, 234, 298, 379, 483, 616, 800, 960] Hz, so that two sets of linearly independent DIBS signals can be configured according to the above selected measurement frequencies. Let the set of measurement frequencies be , the fundamental frequency is According to the linear independent disturbance injection requirement of frequency coupled impedance measurement, the first signal injected into the power generation equipment under test should be of frequency Hz positive sequence disturbance signal, the second injection frequency should be Hz negative sequence disturbance signal. Therefore, the first group of DIBS signals ( ) is configured as The corresponding amplitude is set to a unified preset signal amplitude D (D≠0) according to actual needs. In this example, the preset signal amplitude is determined to be 25V, and the other frequencies (frequency is not ) is configured as 0, and the first group of DIBS signals corresponds to positive sequence disturbance signals; Figures 6 and 7 As shown, Figure 6 is the time domain waveform of the first group of DIBS signals, Figure 7 is the amplitude-frequency characteristic curve of the first group of DIBS signals; Figure 7 It can be seen The disturbance amplitude at each measurement frequency is 15~20V, that is, Figure 7 The amplitude-frequency characteristics shown are different from the expected 25V. At the same time, the non-set frequency (non- ) is not zero either. This is because the DIBS signal approximates the target amplitude-frequency characteristic through a binary sequence rather than precisely controlling the amplitude-frequency characteristic.

[0089] Then the second injected DIBS signal is designed, that is, the second set of DIBS signals ( ), configure the frequency of the second set of DIBS signals to , the corresponding amplitude and Keep consistent and set D=25V. The other frequencies (frequency is not ) is set to 0, and the second group of DIBS signals corresponds to negative-sequence disturbance signals; according to the above amplitude and frequency configuration, two groups of linearly independent DIBS signals can be obtained, which are input into the power generation equipment under test as positive-sequence disturbance signals and negative-sequence disturbance signals respectively.

[0090] After completing the DIBS signal configuration, you can perform three-phase injection of the DIBS signal. When injecting for the first time, inject the signal into the A phase of the power generation equipment. , B phase injection ; During the second injection, inject into the A phase of the power generation equipment , B phase injection , thus avoiding the introduction of zero-sequence components.

[0091] After the DIBS signal is injected, the DIBS excitation-response signal is analyzed and processed. The two DIBS injections introduce both positive-sequence and negative-sequence disturbances. Furthermore, because the DIBS signal cannot precisely design the desired spectral characteristics, in addition to the disturbance amplitude at the set frequency, weaker disturbance amplitudes also exist at non-set frequencies. Therefore, when analyzing and processing the excitation-response signal, it is necessary to account for clutter interference at non-set frequencies to achieve accurate measurement of the frequency-coupled impedance.

[0092] Specifically, after the first injection (i.e., the positive sequence disturbance signal injection), it is necessary to extract the sampling values ​​of the three-phase voltage signal and the three-phase current signal of the port of the tested power generation equipment with a duration of 1s, and extract the set frequency through Fourier analysis. Signal components at and non-set frequencies The clutter component at the position is considered together with the set frequency component as the actual positive sequence disturbance signal injected into the power generation equipment under test for subsequent frequency coupling calculation. When the three-phase voltage signal of the port is Quantity and The components are separated in phase sequence and the positive sequence components are extracted to obtain and ; For the three-phase current signal of the port Quantity and The components are separated in phase sequence and the positive sequence components are extracted to obtain and .when When the three-phase voltage signal and the three-phase current signal of the port are The components are separated in phase sequence and the positive sequence components are extracted to obtain and ; For the three-phase voltage signal and the three-phase current signal of the port The components are separated in phase sequence and the negative sequence components are extracted to obtain and .

[0093] After the second injection (i.e., negative sequence disturbance signal injection), similarly, the sampling values ​​of the three-phase voltage signal and three-phase current signal with a duration of 1s at the port of the tested power generation equipment are extracted, and the set frequency is extracted through Fourier analysis. Signal components at and non-set frequencies When When the three-phase voltage signal of the power generation equipment port is Quantity and The components are separated in phase sequence and the positive sequence components are extracted to obtain and ; For three-phase current signal Quantity and The components are separated in phase sequence and the positive sequence components are extracted to obtain and .when When the three-phase voltage signal and the three-phase current signal are The components are separated in phase sequence and the positive sequence components are extracted to obtain and ; For three-phase voltage signal and three-phase current signal The components are separated in phase sequence and the negative sequence components are extracted to obtain and .

[0094] In combination with all the above 、 、 、 、 、 、 and Then, substitute it into the frequency coupling admittance matrix calculation formula: , the frequency coupling characteristics of the power generation equipment under test are calculated , complete the impedance measurement, the above is the entire calculation process of the frequency coupling characteristics; Figure 8 As shown, Figure 8 The impedance measurement results of this example are shown in Figure 2. Figure 8 In the figure, the blue asterisk indicates the impedance measurement result (i.e., the measurement result) obtained by the DIBS injection method in this application, and the red solid line indicates the analytical impedance model (i.e., the actual admittance) obtained by mathematical deduction. Figure 8In the example, (a) is the sub-admittance element The amplitude-frequency characteristic measurement results and actual value Bode diagram, (b) is the sub-admittance element The amplitude-frequency characteristic measurement results and actual value Bode diagram, (c) is the sub-admittance element The Bode diagram of the phase-frequency characteristic measurement results and actual values, (d) is the sub-admittance element The phase-frequency characteristic measurement results and actual value Bode diagram; Figure 8 It can be seen that the two results are basically consistent, thus verifying the accuracy of the frequency coupling characteristic calculation method provided in the embodiment of the present application.

[0095] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the method for calculating the frequency coupling characteristics of the present application. More simple transformations based on this technical concept are all within the scope of protection of the present application.

[0096] This application also provides a frequency coupling characteristic calculation device, please refer to Figure 9 , the frequency coupling characteristic calculation device includes:

[0097] The disturbance injection module 10 is used to inject the positive-sequence disturbance signal and the negative-sequence disturbance signal into the power generation equipment under test, respectively, to obtain the positive-sequence disturbance response signal and the negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include the three-phase voltage signal and the three-phase current signal of the port of the power generation equipment under test;

[0098] A Fourier analysis module 20 is used to perform Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal to obtain corresponding voltage signal components and current signal components;

[0099] The phase sequence separation module 30 is used to perform phase sequence separation on the voltage signal component and the current signal component respectively to obtain the voltage signal phase sequence component and the current signal phase sequence component;

[0100] The characteristic calculation module 40 is used to calculate the frequency coupling admittance matrix based on the phase sequence component of the voltage signal and the phase sequence component of the current signal to obtain a frequency coupling characteristic calculation result.

[0101] The frequency coupling characteristic calculation device provided in this application utilizes the frequency coupling characteristic calculation method described in the aforementioned embodiments, resolving the technical issues of low efficiency and accuracy in frequency coupling characteristic calculations in related technologies. Compared to related technologies, the frequency coupling characteristic calculation device provided in this application achieves the same beneficial effects as the frequency coupling characteristic calculation method described in the aforementioned embodiments. Other technical features of the frequency coupling characteristic calculation device are the same as those disclosed in the aforementioned embodiments and are not further elaborated here.

[0102] The present application provides a frequency coupling characteristic calculation device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the frequency coupling characteristic calculation method in the above-mentioned embodiment 1.

[0103] Reference below Figure 10 , which shows a schematic diagram of the structure of a frequency coupling characteristic calculation device suitable for implementing the embodiments of the present application. The frequency coupling characteristic calculation device in the embodiments of the present application may include, but is not limited to, mobile terminals such as laptop computers and PADs (Portable Application Descriptions), as well as fixed terminals such as desktop computers. Figure 10 The frequency coupling characteristic calculation device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0104] like Figure 10As shown, the frequency coupling characteristics calculation device may include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes based on programs stored in a read-only memory (ROM) 1002 or programs loaded from a storage device 1003 into a random access memory (RAM) 1004. RAM 1004 also stores various programs and data required for the operation of the frequency coupling characteristics calculation device. Processing device 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007, such as a touchscreen, touchpad, keyboard, mouse, image sensor, microphone, etc.; output devices 1008, such as a liquid crystal display (LCD), speaker, vibrator, etc.; storage device 1003, such as a magnetic tape or hard disk; and communication device 1009. The communication device 1009 can allow the frequency coupling characteristic calculation device to communicate wirelessly or wired with other devices to exchange data. Although the figure shows a frequency coupling characteristic calculation device with various systems, it should be understood that it is not required to implement or have all of the systems shown. More or fewer systems may be implemented or have alternatively.

[0105] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program comprising program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0106] The frequency coupling characteristic calculation device provided in this application utilizes the frequency coupling characteristic calculation method described in the aforementioned embodiments, resolving the technical issues of low efficiency and accuracy in frequency coupling characteristic calculations in related technologies. Compared to related technologies, the frequency coupling characteristic calculation device provided in this application achieves the same beneficial effects as the frequency coupling characteristic calculation method described in the aforementioned embodiments. Other technical features of this frequency coupling characteristic calculation device are the same as those disclosed in the aforementioned embodiments and are not further elaborated here.

[0107] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0108] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0109] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, a computer program) stored thereon, wherein the computer-readable program instructions are used to execute the frequency coupling characteristic calculation method in the above embodiment.

[0110] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0111] The computer-readable storage medium may be included in the frequency coupling characteristic calculation device; or may exist independently without being assembled into the frequency coupling characteristic calculation device.

[0112] The above-mentioned computer-readable storage medium carries one or more programs. When the above-mentioned one or more programs are executed by the frequency coupling characteristic calculation device, the frequency coupling characteristic calculation device: injects the positive-sequence disturbance signal and the negative-sequence disturbance signal into the power generation equipment under test respectively, and obtains the positive-sequence disturbance response signal and the negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two groups of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include the three-phase voltage signal and the three-phase current signal of the port of the power generation equipment under test; Fourier analysis is performed on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively to obtain corresponding voltage signal components and current signal components; phase sequence separation is performed on the voltage signal components and the current signal components respectively to obtain voltage signal phase sequence components and current signal phase sequence components; based on the voltage signal phase sequence components and the current signal phase sequence components, the frequency coupling admittance matrix is ​​calculated to obtain the frequency coupling characteristic calculation result.

[0113] Computer program code for performing the operations of the present application may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0114] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0115] The modules described in the embodiments of the present application may be implemented in software or hardware, wherein the name of a module does not necessarily limit the unit itself.

[0116] The computer-readable storage medium provided in this application stores computer-readable program instructions (i.e., a computer program) for executing the aforementioned method for calculating frequency coupling characteristics. This computer-readable storage medium can address the technical issues of low efficiency and accuracy in frequency coupling characteristic calculations in related technologies. Compared to related technologies, the beneficial effects of the computer-readable storage medium provided in this application are similar to those of the frequency coupling characteristic calculation method provided in the aforementioned embodiments and are not further elaborated here.

[0117] The present application also provides a computer program product, including a computer program, which implements the steps of the above-mentioned frequency coupling characteristic calculation method when executed by a processor.

[0118] The computer program product provided in this application can address the technical issues of low efficiency and accuracy in frequency coupling characteristic calculations in related technologies. Compared to related technologies, the beneficial effects of the computer program product provided in this application are the same as those of the frequency coupling characteristic calculation method provided in the above-mentioned embodiments, and are not further elaborated here.

[0119] The above description is only part of the embodiments of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for calculating frequency coupling characteristics, characterized in that: The frequency coupling characteristic calculation includes: Injecting a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test, respectively, to obtain a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent discrete interval binary sequence signals; the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include a three-phase voltage signal and a three-phase current signal of the port of the power generation equipment under test; Performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively to obtain corresponding voltage signal components and current signal components; Separating the voltage signal component and the current signal component in phase sequence to obtain a voltage signal phase sequence component and a current signal phase sequence component; Calculating a frequency coupling admittance matrix based on the phase sequence component of the voltage signal and the phase sequence component of the current signal to obtain a frequency coupling characteristic calculation result; The positive-sequence disturbance signal corresponds to a plurality of first preset signal frequencies, the amplitude of the positive-sequence disturbance signal at each of the first preset signal frequencies is a preset signal amplitude and is not 0, and the amplitude of the positive-sequence disturbance signal at frequencies other than the first preset signal frequencies is 0; the negative-sequence disturbance signal corresponds to a plurality of second preset signal frequencies, the amplitude of the negative-sequence disturbance signal at each of the second preset signal frequencies is a preset signal amplitude and is not 0, and the amplitude of the negative-sequence disturbance signal at frequencies other than the second preset signal frequencies is 0; the second preset signal frequency = the first preset signal frequency - 2× the fundamental frequency; The step of performing Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal to obtain corresponding voltage signal components and current signal components comprises: Sampling the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively according to a preset signal length to obtain a first sampling signal corresponding to the positive-sequence disturbance response signal and a second sampling signal corresponding to the negative-sequence disturbance response signal; Extracting, by Fourier analysis, a first positive-sequence disturbance voltage signal component and a first positive-sequence disturbance current signal component of the first sampling signal at the first preset signal frequency, and a second positive-sequence disturbance voltage signal component and a second positive-sequence disturbance current signal component of the first sampling signal at the second preset signal frequency; Through Fourier analysis, a first negative-sequence disturbance voltage signal component and a first negative-sequence disturbance current signal component of the second sampling signal at the first preset signal frequency, as well as a second negative-sequence disturbance voltage signal component and a second negative-sequence disturbance current signal component of the second sampling signal at the second preset signal frequency are extracted.

2. The frequency coupling characteristic calculation method according to claim 1, wherein: The steps of injecting the positive-sequence disturbance signal and the negative-sequence disturbance signal into the power generation equipment under test, respectively, and obtaining the positive-sequence disturbance response signal and the negative-sequence disturbance response signal of the port of the power generation equipment under test include: Injecting the positive-sequence disturbance signal into the A-phase input terminal of the power generation device under test, and injecting the inverse phase signal of the positive-sequence disturbance signal into the B-phase input terminal of the power generation device under test, to obtain a positive-sequence disturbance response signal of the port of the power generation device under test; The negative-sequence disturbance signal is injected into the A-phase input terminal of the power generation equipment under test, and the inverted signal of the negative-sequence disturbance signal is injected into the B-phase input terminal of the power generation equipment under test to obtain the negative-sequence disturbance response signal of the port of the power generation equipment under test.

3. The frequency coupling characteristic calculation method according to claim 1, wherein: The step of performing phase sequence separation on the voltage signal component and the current signal component to obtain the voltage signal phase sequence component and the current signal phase sequence component comprises: performing phase sequence separation on the voltage signal component and the current signal component respectively to obtain a phase sequence separation signal; When the second preset signal frequency is less than 0, performing positive sequence extraction on the phase sequence separation signal at the first preset signal frequency and the second preset signal frequency respectively to obtain a voltage positive sequence component and a current positive sequence component; When the second preset signal frequency is greater than 0, the phase sequence separation signal is subjected to positive sequence extraction at the first preset signal frequency to obtain a voltage positive sequence component and a current positive sequence component, and the phase sequence separation signal is subjected to negative sequence extraction at the second preset signal frequency to obtain a voltage negative sequence component and a current negative sequence component.

4. The method for calculating frequency coupling characteristics according to claim 1, wherein: The calculation formula of the frequency coupling admittance matrix is: ;in, is the frequency coupling admittance matrix, 、 、 、 are four sub-admittance elements, is the phase sequence component of the current signal at the first preset signal frequency corresponding to the positive-sequence disturbance response signal, is the phase sequence component of the voltage signal at the first preset signal frequency corresponding to the positive-sequence disturbance response signal, is the phase sequence component of the current signal at the second preset signal frequency corresponding to the positive-sequence disturbance response signal, is the phase sequence component of the voltage signal at the second preset signal frequency corresponding to the positive-sequence disturbance response signal, is the phase sequence component of the current signal at the first preset signal frequency corresponding to the negative-sequence disturbance response signal, is the phase sequence component of the voltage signal at the first preset signal frequency corresponding to the negative-sequence disturbance response signal, is the phase sequence component of the current signal at the second preset signal frequency corresponding to the negative-sequence disturbance response signal, It is the phase sequence component of the voltage signal at the second preset signal frequency corresponding to the negative-sequence disturbance response signal.

5. A frequency coupling characteristic calculation device, characterized in that: The frequency coupling characteristic calculation device includes: A disturbance injection module is configured to inject a positive-sequence disturbance signal and a negative-sequence disturbance signal into the power generation equipment under test, respectively, to obtain a positive-sequence disturbance response signal and a negative-sequence disturbance response signal of the port of the power generation equipment under test; wherein the positive-sequence disturbance signal and the negative-sequence disturbance signal are two sets of linearly independent discrete interval binary sequence signals; and the positive-sequence disturbance response signal and the negative-sequence disturbance response signal both include a three-phase voltage signal and a three-phase current signal of the port of the power generation equipment under test; A Fourier analysis module, configured to perform Fourier analysis on the positive-sequence disturbance response signal and the negative-sequence disturbance response signal, respectively, to obtain corresponding voltage signal components and current signal components; A phase sequence separation module is used to perform phase sequence separation on the voltage signal component and the current signal component respectively to obtain a voltage signal phase sequence component and a current signal phase sequence component; a characteristic calculation module, configured to calculate a frequency coupling admittance matrix based on the phase sequence component of the voltage signal and the phase sequence component of the current signal, and obtain a frequency coupling characteristic calculation result; The positive-sequence disturbance signal corresponds to a plurality of first preset signal frequencies, the amplitude of the positive-sequence disturbance signal at each of the first preset signal frequencies is a preset signal amplitude and is not 0, and the amplitude of the positive-sequence disturbance signal at frequencies other than the first preset signal frequencies is 0; the negative-sequence disturbance signal corresponds to a plurality of second preset signal frequencies, the amplitude of the negative-sequence disturbance signal at each of the second preset signal frequencies is a preset signal amplitude and is not 0, and the amplitude of the negative-sequence disturbance signal at frequencies other than the second preset signal frequencies is 0; the second preset signal frequency = the first preset signal frequency - 2× the fundamental frequency; The Fourier analysis module is also used to sample the positive-sequence disturbance response signal and the negative-sequence disturbance response signal respectively according to a preset signal length to obtain a first sampling signal corresponding to the positive-sequence disturbance response signal and a second sampling signal corresponding to the negative-sequence disturbance response signal; through the Fourier analysis method, extract the first positive-sequence disturbance voltage signal component and the first positive-sequence disturbance current signal component of the first sampling signal at the first preset signal frequency, and the second positive-sequence disturbance voltage signal component and the second positive-sequence disturbance current signal component of the first sampling signal at the second preset signal frequency; through the Fourier analysis method, extract the first negative-sequence disturbance voltage signal component and the first negative-sequence disturbance current signal component of the second sampling signal at the first preset signal frequency, and the second negative-sequence disturbance voltage signal component and the second negative-sequence disturbance current signal component of the second sampling signal at the second preset signal frequency.

6. A frequency coupling characteristic calculation device, characterized in that: The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the frequency coupling characteristic calculation method according to any one of claims 1 to 4.

7. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the frequency coupling characteristic calculation method according to any one of claims 1 to 4 are implemented.

8. A computer program product, characterized in that The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the frequency coupling characteristic calculation method according to any one of claims 1 to 4 are implemented.

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