Oscillation signal detection method, device, equipment, storage medium and program product

Abstract

The invention relates to an oscillation signal detection method and device, equipment, a storage medium and a program product. The method comprises the following steps: acquiring a time domain voltage signal from a power system; performing time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; time-frequency rearrangement is carried out on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, the energy concentration ratio of time-frequency representation of the second time-frequency representation complex matrix is higher than that of the first time-frequency representation complex matrix, and a time-frequency representation spectrogram is generated based on the second time-frequency representation complex matrix; extracting an instantaneous frequency spectral line from the time-frequency representation spectrogram, and carrying out instantaneous frequency identification to obtain an instantaneous frequency value; and based on the instantaneous frequency value, determining whether harmonic waves and / or inter-harmonic waves exist in the time domain voltage signal, and in response to the existence of the harmonic waves and / or inter-harmonic waves in the time domain voltage signal, determining that an oscillation signal exists in the power system. The oscillation signal in the power system can be accurately detected, and a basis is provided for stability analysis of the power system.

Description

Technical Field

[0001] This disclosure relates to the field of power system technology, and in particular to an oscillation signal detection method, apparatus, equipment, storage medium, and program product. Background Technology

[0002] This section is intended to provide background or context for embodiments of this disclosure. The description herein is not intended to imply that it is prior art simply because it is included in this section.

[0003] With the rapid development of power transmission and transformation technology and the large-scale application of power electronic equipment, the "dual high" characteristics (high proportion of new energy power generation and high proportion of power electronic equipment) of the new power system are becoming increasingly prominent, which brings about stability problems different from those of the traditional power system.

[0004] Due to the presence of numerous power electronic devices, the voltage signals of new power systems exhibit harmonic and interharmonic components that differ from those of traditional power systems. The most significant characteristic is the wide frequency distribution of the signal, ranging from a few hertz to hundreds or even thousands of hertz, resulting in frequency oscillations over a broad range. The resulting signal is thus termed a broadband oscillating signal.

[0005] Traditional stability analysis methods are not applicable to the broadband oscillation phenomenon in new power systems, and new analysis methods need to be designed. Summary of the Invention

[0006] In order to at least partially solve one of the technical problems in the related art, this disclosure provides an oscillation signal detection method, apparatus, device, storage medium, and program product.

[0007] To achieve the above objectives, a first aspect of the exemplary embodiments of this disclosure provides an oscillation signal detection method, comprising: Obtain time-domain voltage signals from the target power system; Time-frequency analysis is performed on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; The first time-frequency representation complex matrix is ​​rearranged in time and frequency to obtain a second time-frequency representation complex matrix. The energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix. A time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix. Instantaneous frequency spectral lines are extracted from the time-frequency representation spectrum, and instantaneous frequency identification is performed on the instantaneous frequency spectral lines to obtain the instantaneous frequency values ​​of the instantaneous frequency spectral lines; Based on the instantaneous frequency value, it is determined whether there are harmonics and / or interharmonics in the time-domain voltage signal. In response to the presence of harmonics and / or interharmonics in the time-domain voltage signal, it is determined that there is an oscillation signal in the target power system.

[0008] In some exemplary embodiments, after determining that an oscillation signal exists in the target power system, the method further includes: The time period value of the instantaneous frequency spectrum corresponding to the harmonics and / or interharmonics is obtained by identifying the time period of the instantaneous frequency spectrum. Output the instantaneous frequency value and the time period corresponding to the harmonic and / or interharmonic.

[0009] In some exemplary embodiments, the step of performing time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix includes: Based on the mother wavelet function, a family of wavelet functions controlled by scale and time parameters is constructed. The wavelet function family and the time-domain voltage signal are subjected to an inner product operation under scaling and time shifting. The time-domain voltage signal is then projected onto the wavelet function family to obtain a continuous wavelet transform complex matrix, which serves as the first time-frequency representation complex matrix.

[0010] In some exemplary embodiments, the step of time-frequency rearranging the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix, and generating a time-frequency representation spectrum based on the second time-frequency representation complex matrix, includes: The first time-frequency representation complex matrix is ​​sharpened based on wavelet synchronous compression transform to obtain the second time-frequency representation complex matrix. The time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix.

[0011] In some exemplary embodiments, the step of extracting instantaneous frequency spectral lines from the time-frequency representation spectrum includes iteratively performing the following operations until the number of instantaneous frequency spectral lines extracted from the time-frequency representation spectrum equals a quantity threshold: Extract the time-frequency ridge line with the strongest energy from the current time-frequency representation spectrum as the instantaneous frequency spectrum line; In the second time-frequency representation complex matrix, the values ​​of the complex matrix elements corresponding to the frequency position of the extracted instantaneous frequency spectrum line and the neighborhood are set to zero, and the second time-frequency representation complex matrix is ​​updated. The current time-frequency representation spectrum is updated based on the updated second time-frequency representation complex matrix.

[0012] In some exemplary embodiments, determining whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value includes: Determine the relationship between the instantaneous frequency value and the frequency threshold; In response to the instantaneous frequency value being an integer multiple of the frequency threshold, it is determined that harmonics exist in the time-domain voltage signal; In response to the instantaneous frequency value being a non-integer multiple of the frequency threshold, it is determined that an interharmonic exists in the time-domain voltage signal.

[0013] Based on the same inventive concept, a second aspect of the exemplary embodiments of this disclosure provides an oscillation signal detection device, comprising: The time-domain voltage signal acquisition module is configured to acquire time-domain voltage signals from the target power system; The time-frequency analysis module is configured to perform time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; The time-frequency representation spectrum determination module is configured to perform time-frequency rearrangement on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix, and generate a time-frequency representation spectrum based on the second time-frequency representation complex matrix; The instantaneous frequency spectrum analysis module is configured to extract instantaneous frequency spectrum lines from the time-frequency representation spectrum, perform instantaneous frequency identification on the instantaneous frequency spectrum lines, and obtain the instantaneous frequency value of the instantaneous frequency spectrum lines. The oscillation phenomenon determination module is configured to determine whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value, and to determine that an oscillation signal exists in the target power system in response to the presence of harmonics and / or interharmonics in the time-domain voltage signal.

[0014] Based on the same inventive concept, a third aspect of the exemplary embodiments of this disclosure provides an electronic device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method as described in the first aspect.

[0015] Based on the same inventive concept, a fourth aspect of the exemplary embodiments of this disclosure provides a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implement the steps of the method as described in the first aspect.

[0016] Based on the same inventive concept, a fifth aspect of the exemplary embodiments of this disclosure provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the method as described in the first aspect.

[0017] The technical solution provided in this disclosure has the following advantages compared with the prior art: This disclosure can accurately determine whether there are oscillation signals in a power system, providing a basis for the stability analysis of the power system and improving the safety of the power system. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0019] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0020] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0021] Figure 1 A schematic diagram illustrating an application scenario of the oscillation signal detection method provided in an exemplary embodiment of this disclosure; Figure 2 A schematic flowchart of an oscillation signal detection method provided for an exemplary embodiment of this disclosure; Figure 3 A schematic diagram of a low-resolution time-frequency representation spectrum provided for an exemplary embodiment of this disclosure; Figure 4 A schematic diagram of a low-resolution time-frequency projection planar view provided for an exemplary embodiment of this disclosure; Figure 5 A schematic diagram of a high-resolution time-frequency representation spectrum provided for an exemplary embodiment of this disclosure; Figure 6 A schematic diagram of a high-resolution time-frequency projection planar view provided for an exemplary embodiment of this disclosure; Figure 7 A schematic diagram of an instantaneous frequency spectrum provided for an exemplary embodiment of this disclosure; Figure 8 A flowchart illustrating an instantaneous frequency spectrum extraction method provided for an exemplary embodiment of this disclosure; Figure 9 A schematic diagram of an oscillation signal detection device provided as an exemplary embodiment of the present disclosure; Figure 10 A schematic diagram of the structure of an electronic device provided as an exemplary embodiment of the present disclosure. Detailed Implementation

[0022] It is understood that the data involved in this technical solution (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of relevant laws, regulations and related provisions.

[0023] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0024] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0025] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0026] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0027] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0028] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0029] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0030] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0031] As described in the background section, with the rapid development of power transmission and transformation technology and the large-scale application of power electronic equipment, the "dual high" characteristics (high proportion of new energy power generation and high proportion of power electronic equipment) of the new power system are becoming increasingly prominent, which brings about stability problems different from those of the traditional power system.

[0032] Due to the presence of numerous power electronic devices, the voltage signals of new power systems exhibit harmonic and interharmonic components that differ from those of traditional power systems. The most significant characteristic is the wide frequency distribution of the signal, ranging from a few hertz to hundreds or even thousands of hertz, resulting in frequency oscillations over a broad range. The resulting signal is thus termed a broadband oscillating signal.

[0033] However, the inventors of this disclosure have discovered that traditional stability analysis theory is difficult to apply to the broadband oscillation phenomenon in novel power systems, and new analysis methods need to be designed.

[0034] To address the aforementioned problems, this disclosure provides an oscillation signal detection scheme, specifically including: A time-domain voltage signal is obtained from the target power system; time-frequency analysis is performed on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; the first time-frequency representation complex matrix is ​​rearranged in time and frequency to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix; a time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix; instantaneous frequency spectral lines are extracted from the time-frequency representation spectrum, and instantaneous frequency identification is performed on the instantaneous frequency spectral lines to obtain the instantaneous frequency values ​​of the instantaneous frequency spectral lines; based on the instantaneous frequency values, it is determined whether harmonics and / or interharmonics exist in the time-domain voltage signal; in response to the presence of harmonics and / or interharmonics in the time-domain voltage signal, it is determined that an oscillation signal exists in the target power system.

[0035] This disclosure can accurately determine whether there are oscillation signals in a power system, providing a basis for the stability analysis of the power system.

[0036] After introducing the basic principles of this disclosure, various non-limiting embodiments of this disclosure will be described in detail below.

[0037] refer to Figure 1 This is a schematic diagram of an application scenario of the oscillation signal detection method provided by the exemplary embodiments of this disclosure.

[0038] This application scenario includes a signal acquisition device 110, a server 120, and a terminal device 130. The signal acquisition device 110, server 120, and terminal device 130 can all be connected via wired or wireless communication networks to achieve data interaction.

[0039] The signal acquisition device 110 can be a device in a power system that has the function of acquiring time-domain voltage signals. For example, voltage transformers (including electromagnetic voltage transformers, capacitive voltage transformers, and electronic voltage transformers), synchronous phasor measurement units, fault recorders, and power quality monitoring devices.

[0040] Server 120 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0041] Terminal device 130 may be an electronic device located close to the user side, possessing data transmission and multimedia input / output functions, including but not limited to desktop computers, mobile phones, portable computers, tablet computers, media players, smart wearable devices, personal digital assistants (PDAs), or other electronic devices capable of performing the aforementioned functions. This electronic device may include a processor and a display screen with touch input functionality. The display screen is used to present a graphical user interface (GUI), which can display an application interface. The processor is used to process application data, generate the GUI, and control the display of the GUI on the screen.

[0042] In some exemplary embodiments, the oscillation signal detection method may be run on server 120.

[0043] When the oscillation signal detection method is running on server 120, server 120 is used to provide oscillation signal detection services to users of terminal device 130, and terminal device 130 has a client installed that communicates with server 120.

[0044] Signal acquisition device 110 acquires time-domain voltage signals from the target power system.

[0045] Server 120 acquires time-domain voltage signals from signal acquisition device 110 in the target power system; performs time-frequency analysis on the time-domain voltage signals based on time-frequency transformation to obtain a first time-frequency representation complex matrix; performs time-frequency rearrangement on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix; generates a time-frequency representation spectrum based on the second time-frequency representation complex matrix; extracts instantaneous frequency spectral lines from the time-frequency representation spectrum, performs instantaneous frequency identification on the instantaneous frequency spectral lines to obtain the instantaneous frequency values ​​of the instantaneous frequency spectral lines; determines whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency values; and determines that an oscillation signal exists in the target power system in response to the presence of harmonics and / or interharmonics in the time-domain voltage signal.

[0046] Server 120 sends the oscillation signal detection results (whether an oscillation signal exists in the target power system, and if so, detailed information about the oscillation signal) to the client. The client then displays the oscillation signal detection results to the user to help the user take suppression measures based on the oscillation signal detection results and ensure the stability of the power system.

[0047] The following is combined with Figure 1 The application scenarios described above illustrate the oscillation signal detection method according to exemplary embodiments of this disclosure. It should be noted that the above application scenarios are shown only to facilitate understanding of the spirit and principles of this disclosure, and the embodiments of this disclosure are not limited in any way. Rather, the embodiments of this disclosure can be applied to any applicable scenario.

[0048] refer to Figure 2 This is a schematic flowchart of an oscillation signal detection method provided by an exemplary embodiment of the present disclosure.

[0049] This method can be executed by an oscillation signal detection device, which can be implemented in software and / or hardware and is generally integrated into an electronic device.

[0050] like Figure 2 As shown, the oscillation signal detection method includes the following steps: Step S210: Obtain the time-domain voltage signal from the target power system.

[0051] In some exemplary embodiments, acquiring the time-domain voltage signal from the target power system includes: The target power system is monitored to obtain a one-dimensional time-domain voltage signal.

[0052] Through the above exemplary embodiments, a one-dimensional time-domain voltage signal selected from several measurement signals can characterize the features of a broadband oscillation signal, providing a basis for the detection of the oscillation signal in subsequent steps.

[0053] The theoretical basis for the detection of oscillation signals in this disclosure will be introduced below: As an example, in a broadband oscillating signal, the fundamental signal component has a frequency of 50 Hz (Hertz, the unit of frequency in the International System of Units, which is a measure of the number of repetitions of periodic variations per second). Signal components whose frequency is an integer multiple of the fundamental frequency are harmonics, and signal components whose frequency is not an integer multiple of the fundamental frequency are interharmonics.

[0054] Among them, the broadband oscillation signal can be regarded as the superposition of multiple cosine or sine signals. The signals only differ in the numerical value of their parameters, but there is no substantial difference between them.

[0055] In this context, the frequency value of each cosine or sine signal is a constant, which means that its instantaneous frequency (IF) always remains unchanged, and the value of IF is equal to its frequency value.

[0056] The IF is defined as follows: Now assume a time-domain voltage signal of a certain dimension. x ( t )= A ( t cos( φ ( t The analytic signal corresponding to it is a complex signal. z ( t ), its expression is z ( t )= x ( t )+ j H[ x ( t In the formula, j H[] is the imaginary unit, and H[] is the real signal. x ( t The Hilbert transform of is defined as follows: (1) Where PV represents the Cauchy principal value. Based on the obtained analytical signal... z ( t One-dimensional time-domain voltage signal x ( t The IF of ) is defined as z ( t The derivative of the phase angle, i.e.: (2) Obviously, for any pure cosine or sine signal s ( t )= Acos(2π f 0+ φ For 0), its IF is always equal to its own frequency. f 0.

[0057] As an example, taking a broadband oscillation signal containing a fundamental wave and several harmonics and interharmonics in a power system as an example, the oscillation signal detection method provided in this disclosure is illustrated: A broadband oscillation signal is simulated by superimposing several sinusoidal signals, including: a fundamental signal with a frequency of 50 Hz, harmonic signals with frequencies of 150 Hz and 1000 Hz, and an interharmonic signal with a frequency of 320 Hz.

[0058] The sampling frequency is set to fs = 1 × 10 4 Hz, sampling length is 10 4 The sampling time is 1 second. The amplitude and initial phase angle of each signal are different; therefore, in this embodiment, the expression for the broadband oscillation signal is... x ( t As shown below.

[0059] (3) In the formula, WN( t ) represents Gaussian white noise with a mean of 0 and a standard deviation of 1, conforming to a standard normal distribution; χ [] This is an interval characteristic function, which has a value of 1 only on the closed interval specified by the function, and a value of 0 on other intervals. T This refers to the sampling duration.

[0060] Step S220: Perform time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain the first time-frequency representation complex matrix.

[0061] In some exemplary embodiments, acquiring the time-domain voltage signal from the target power system includes: The target power system is monitored to obtain a one-dimensional time-domain voltage signal; Then, the time-frequency analysis of the time-domain voltage signal based on time-frequency transformation to obtain the first time-frequency representation complex matrix includes: The one-dimensional time-domain voltage signal is mapped to a two-dimensional first time-frequency representation complex matrix, wherein the dimensions of the two-dimensional first time-frequency representation complex matrix are time and frequency, and the matrix elements of the two-dimensional first time-frequency representation complex matrix are complex values ​​used to characterize the energy and phase of the signal at the corresponding time and frequency points.

[0062] In some exemplary embodiments, the step of performing time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix includes: The time-frequency analysis of the time-domain voltage signal is performed based on continuous wavelet transform to obtain the continuous wavelet transform complex matrix.

[0063] Wherein, the time-frequency transform is a continuous wavelet transform, then the first time-frequency representation complex matrix is ​​a continuous wavelet transform complex matrix.

[0064] In some exemplary embodiments, the step of performing time-frequency analysis on the time-domain voltage signal based on continuous wavelet transform to obtain a continuous wavelet transform complex matrix includes: Based on the mother wavelet function, a family of wavelet functions controlled by scale and time parameters is constructed. The family of wavelet functions is then subjected to an inner product operation with the time-domain voltage signal under scaling and time shift. The time-domain voltage signal is then projected onto the family of wavelet functions to obtain the continuous wavelet transform complex matrix.

[0065] As an example, consider a one-dimensional time-domain voltage signal. h ( t Performing a continuous wavelet transform (CWT) yields a two-dimensional CWT complex matrix. Wf ( a , b The specific expression is as follows: (4) In the formula, It's wavelet ψ ( t Fourier transform of ) It's wavelet ψ ( t The conjugate operation of the Fourier transform. a It is a scale. b It's time.

[0066] In performing continuous wavelet transform, the bump wavelet is chosen as the mother wavelet function. The bump wavelet is characterized by being a wavelet defined in the frequency domain. The Fourier transform function expression of the bump wavelet in the frequency domain is as follows: (5) In the formula, χ [ ] It is an indicator function.

[0067] Through the above exemplary embodiments, preliminary time-frequency analysis of the time-domain voltage signal is achieved, with reference to... Figure 3 This is the time-frequency representation spectrum corresponding to the preliminary time-frequency analysis results.

[0068] Among them, the CWT complex matrix is ​​obtained. Wf ( a , b The absolute value of )Wf ( a , b This yields the corresponding three-dimensional time-frequency representation (TFR) spectrum, which is then visually presented through plotting, such as... Figure 3 As shown.

[0069] Projecting it onto the time-frequency plane yields a two-dimensional time-frequency projection plane diagram, as shown below. Figure 4 As shown.

[0070] However, reference Figure 3 and Figure 4 However, the resolution has a certain degree of ambiguity, and the accuracy of identification is not high. Therefore, this disclosure further improves the accuracy of identification through step S130.

[0071] It should be noted that, in actual implementation, there is no need to generate [the necessary data]. Figure 3 and Figure 4 Here, Figure 3 and Figure 4 This is only used to illustrate that because the energy concentration of the time-frequency representation of the first time-frequency representation complex matrix is ​​insufficient, the resolution of the time-frequency representation spectrum generated in this stage has a certain degree of ambiguity and the accuracy of identification is not high. Therefore, this disclosure provides a technical means to further improve the accuracy of identification through step S130.

[0072] Step S230: Perform time-frequency rearrangement on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix. The energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix. Based on the second time-frequency representation complex matrix, generate a time-frequency representation spectrum.

[0073] In some exemplary embodiments, the step of time-frequency rearranging the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix, and generating a time-frequency representation spectrum based on the second time-frequency representation complex matrix, includes: The first time-frequency representation complex matrix is ​​sharpened based on wavelet synchronous compression transform to obtain the second time-frequency representation complex matrix. The time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix.

[0074] In some exemplary embodiments, the step of sharpening the first time-frequency representation complex matrix based on wavelet synchronous compression transform to obtain a second time-frequency representation complex matrix, and generating the time-frequency representation spectrum based on the second time-frequency representation complex matrix, includes: The continuous wavelet transform complex matrix is ​​sharpened by wavelet synchronous compression transform to obtain the sharpened continuous wavelet transform complex matrix. The time-frequency representation spectrum is generated based on the sharpened continuous wavelet transform complex matrix.

[0075] As an example, consider the CWT complex matrix obtained in step S120. Wf ( a , b Sharpening is performed to improve the performance of CWT complex matrices. Wf ( a , b The resolution of the generated time-frequency representation spectrum is increased to display it more accurately and highlight the time-frequency information it contains. To a certain extent, this avoids the resolution blurring problem caused by the Heisenberg uncertainty principle in the CWT results.

[0076] Among them, in complex matrix Wf ( a , b Based on this, the complex matrix is ​​sharpened using Wavelet Synchrosqueezing Transform (WSST) to obtain the sharpened complex matrix. Ts ; The WSST principle involves tracing and redistributing the ambiguous and diffused energy caused by the Heisenberg uncertainty principle in the time-frequency representation spectrum in three-dimensional space and on the time-frequency projection plane. For a given time point, each point in the TFR of the CWT (…) a , b ) mapped to a new point, i.e. ( ω s ( a , b ), b ),in ω s =2π f s Instantaneous frequency to be estimated f s The complex matrix obtained after time-frequency reconstruction of CWT using the WSST method. Ts The expression is: (6) (7) The calculated WSST complex matrix Ts absolute value | Ts |, thereby obtaining a time-frequency representation spectrum TFR' with significantly improved resolution and highly concentrated energy.

[0077] After obtaining the sharpened time-frequency representation spectrum TFR', it is also presented graphically, such as... Figure 5 As shown, it is projected onto the time-frequency plane to obtain a two-dimensional time-frequency projection plane diagram, as shown. Figure 6 As shown.

[0078] Through the above exemplary embodiments, the resolution of the time-frequency representation spectrum TFR' is significantly improved and the energy is highly concentrated, so as to display it more accurately and highlight the time-frequency information contained therein.

[0079] Therefore, in Figure 5 Combination Figure 6 Based on this, the number N of spectral lines representing IF can be determined intuitively.

[0080] As an example, see reference Figure 5 and Figure 6 Among them, four "flat ridge" shaped waveforms can be clearly seen; in the two-dimensional time-frequency projection coordinates, the projection of TFR' is a straight line parallel to the time axis. Although the presence of white noise will cause some numerical fluctuations, the several IF spectral lines representing the instantaneous frequency can still be clearly identified. According to their frequency magnitude, they are denoted as IF1~IF4, respectively. Figure 7 It can be seen that IF1 and IF4 exist throughout all time periods, while IF2 exists from 0 to 0.51 s and IF3 exists from 0.51 to 1 s. Therefore, the number N representing IF is determined to be 4.

[0081] Step S240: Extract instantaneous frequency spectral lines from the time-frequency representation spectrum, perform instantaneous frequency identification on the instantaneous frequency spectral lines, and obtain the instantaneous frequency value of the instantaneous frequency spectral lines.

[0082] In some exemplary embodiments, the step of extracting instantaneous frequency spectral lines from the time-frequency representation spectrum includes iteratively performing the following operations until the number of instantaneous frequency spectral lines extracted from the time-frequency representation spectrum equals a quantity threshold: Extract the time-frequency ridge line with the strongest energy from the current time-frequency representation spectrum as the instantaneous frequency spectrum line; In the second time-frequency representation complex matrix, the values ​​of the complex matrix elements corresponding to the frequency position of the extracted instantaneous frequency spectrum line and the neighborhood are set to zero, and the second time-frequency representation complex matrix is ​​updated. The current time-frequency representation spectrum is updated based on the updated second time-frequency representation complex matrix.

[0083] In specific implementation, refer to Figure 8 Methods for extracting instantaneous frequency spectral lines include: S410. Set the sharpened time-frequency representation spectrum as the current time-frequency representation spectrum, and set its corresponding second time-frequency representation complex matrix as the current second time-frequency representation complex matrix. S420. From the current time-frequency representation spectrum, extract the time-frequency ridge line with the strongest current energy as an instantaneous frequency spectrum line; S430. In the current second time-frequency representation complex matrix, the frequency position corresponding to the extracted instantaneous frequency spectrum line and the matrix element values ​​in its neighborhood are set to zero to obtain an updated second time-frequency representation complex matrix. S440. Based on the updated second time-frequency representation complex matrix, generate an updated time-frequency representation spectrum and set it as the new current time-frequency representation spectrum, while setting the updated second time-frequency representation complex matrix as the new current second time-frequency representation complex matrix; S450. Determine whether the number of instantaneous frequency spectral lines extracted from the time-frequency representation spectrum is equal to the number threshold. If not, repeat steps S420 to S440 until the number of instantaneous frequency spectral lines extracted from the time-frequency representation spectrum is equal to the number threshold, thereby completing the extraction of instantaneous frequency spectral lines. If yes, end.

[0084] As an example, the instantaneous frequency values ​​of the instantaneous frequency spectrum are shown in Table 1. It can be seen that the calculated values ​​and theoretical values ​​differ only slightly: Table 1 Instantaneous Frequency Values

[0085] Step S250: Based on the instantaneous frequency value, determine whether there are harmonics and / or interharmonics in the time-domain voltage signal; in response to the presence of harmonics and / or interharmonics in the time-domain voltage signal, determine that there is an oscillation signal in the target power system.

[0086] In some exemplary embodiments, determining whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value includes: Based on the instantaneous frequency value and the frequency threshold, it is determined whether there are harmonics and / or interharmonics in the time-domain voltage signal.

[0087] In some exemplary embodiments, determining whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value and a frequency threshold includes: Determine the relationship between the instantaneous frequency value and the frequency threshold; In response to the instantaneous frequency value being an integer multiple of the frequency threshold, it is determined that harmonics exist in the time-domain voltage signal; In response to the instantaneous frequency value being a non-integer multiple of the frequency threshold, it is determined that an interharmonic exists in the time-domain voltage signal.

[0088] Wherein, in response to the instantaneous frequency value being equal to the frequency threshold, the signal component is determined to be the fundamental frequency; In response to the instantaneous frequency value being an integer multiple of the frequency threshold, the signal component is determined to be a harmonic; In response to the instantaneous frequency value being a non-integer multiple of the frequency threshold, the signal component is determined to be an interharmonic.

[0089] In some exemplary embodiments, after determining that an oscillation signal exists in the target power system, the method further includes: The time period value of the instantaneous frequency spectrum corresponding to the harmonics and / or interharmonics is obtained by identifying the time period of the instantaneous frequency spectrum. Output the instantaneous frequency value and the time period corresponding to the harmonic and / or interharmonic.

[0090] In this process, by combining the time-domain and frequency-domain characteristics of the extracted instantaneous frequency spectrum, the existence time and corresponding frequency of each component in the broadband oscillation signal are determined.

[0091] As an example, by determining the extracted frequency values ​​and their multiple relationship with the power frequency of 50Hz, it can be determined that there is always a fundamental frequency and a 20th harmonic in the system. There is a 3rd harmonic in the first half of the sampling time and an interharmonic between the 6th and 7th harmonics in the second half of the sampling time.

[0092] As an example, see reference Figure 7 This demonstrates the distribution of instantaneous frequency spectral lines in the time and frequency domains: It can be seen that IF1 and IF4 exist at all times, while IF2 exists for 0~0.51s and IF3 exists for 0.51~1s.

[0093] The instantaneous frequency of IF1 is 50Hz, the instantaneous frequency of IF4 is 1000Hz, the instantaneous frequency of IF2 is 150Hz, and the instantaneous frequency of IF3 is 320Hz.

[0094] This disclosure can accurately determine whether there are oscillation signals in a power system, providing a basis for the stability analysis of the power system and improving the safety of the power system.

[0095] It should be noted that the method of this embodiment can be executed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method of this embodiment, and the multiple devices will interact with each other to complete the method described.

[0096] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0097] To achieve the above embodiments, this disclosure also proposes an oscillation signal detection device.

[0098] Figure 9 This is a schematic diagram of an oscillation signal detection device provided in an embodiment of the present disclosure. The device can be implemented by software and / or hardware and is generally integrated into an electronic device.

[0099] like Figure 9 As shown, the oscillation signal detection device includes the following modules: The time-domain voltage signal acquisition module 910 is configured to acquire a time-domain voltage signal from the target power system. The time-frequency analysis module 920 is configured to perform time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; The time-frequency representation spectrum determination module 930 is configured to perform time-frequency rearrangement on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix, and generate a time-frequency representation spectrum based on the second time-frequency representation complex matrix; The instantaneous frequency spectrum analysis module 940 is configured to extract instantaneous frequency spectrum lines from the time-frequency representation spectrum, perform instantaneous frequency identification on the instantaneous frequency spectrum lines, and obtain the instantaneous frequency value of the instantaneous frequency spectrum lines. The oscillation phenomenon determination module 950 is configured to determine whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value, and to determine that an oscillation signal exists in the target power system in response to the presence of harmonics and / or interharmonics in the time-domain voltage signal.

[0100] In some exemplary embodiments, the oscillation signal detection device is further configured to: The time period value of the instantaneous frequency spectrum corresponding to the harmonics and / or interharmonics is obtained by identifying the time period of the instantaneous frequency spectrum. Output the instantaneous frequency value and the time period corresponding to the harmonic and / or interharmonic.

[0101] In some exemplary embodiments, the time-frequency analysis module 920 is specifically configured as follows: Based on the mother wavelet function, a family of wavelet functions controlled by scale and time parameters is constructed. The wavelet function family and the time-domain voltage signal are subjected to an inner product operation under scaling and time shifting. The time-domain voltage signal is then projected onto the wavelet function family to obtain a continuous wavelet transform complex matrix, which serves as the first time-frequency representation complex matrix.

[0102] In some exemplary embodiments, the time-frequency representation spectrum determination module 930 is specifically configured as follows: The first time-frequency representation complex matrix is ​​sharpened based on wavelet synchronous compression transform to obtain the second time-frequency representation complex matrix. The time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix.

[0103] In some exemplary embodiments, the instantaneous frequency spectral line analysis module 940 is specifically configured to iteratively perform the following operations until the number of instantaneous frequency spectral lines extracted from the time-frequency representation spectrum equals a number threshold: Extract the time-frequency ridge line with the strongest energy from the current time-frequency representation spectrum as the instantaneous frequency spectrum line; In the second time-frequency representation complex matrix, the values ​​of the complex matrix elements corresponding to the frequency position of the extracted instantaneous frequency spectrum line and the neighborhood are set to zero, and the second time-frequency representation complex matrix is ​​updated. The current time-frequency representation spectrum is updated based on the updated second time-frequency representation complex matrix.

[0104] In some exemplary embodiments, the oscillation phenomenon determination module 950 is specifically configured as follows: Determine the relationship between the instantaneous frequency value and the frequency threshold; In response to the instantaneous frequency value being an integer multiple of the frequency threshold, it is determined that harmonics exist in the time-domain voltage signal; In response to the instantaneous frequency value being a non-integer multiple of the frequency threshold, it is determined that an interharmonic exists in the time-domain voltage signal.

[0105] For ease of description, the above apparatus is described in terms of its functions, divided into various modules. Of course, in implementing this disclosure, the functions of each module can be implemented in one or more software and / or hardware.

[0106] The page element display device provided in this disclosure embodiment can execute the page element display method provided in any embodiment of this disclosure, and has the corresponding functional modules and beneficial effects of executing the method.

[0107] To implement the above embodiments, this disclosure also proposes a computer program product, including a computer program / instructions, which, when executed by a processor, implements the page element display method in the above embodiments.

[0108] Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present disclosure.

[0109] The following is a detailed reference. Figure 10 The diagram illustrates a structural schematic suitable for implementing the electronic device in the embodiments of this disclosure. The electronic device in the embodiments of this disclosure may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 10 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0110] like Figure 10 As shown, the electronic device may include a processor (e.g., a central processing unit, a graphics processing unit, etc.) 1001, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a memory 1008 into a random access memory (RAM) 1003. The RAM 1003 also stores various programs and data required for the operation of the electronic device. The processor 1001, ROM 1002, and RAM 1003 are interconnected via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0111] Typically, the following devices can be connected to the I / O interface 1005: input devices 1006 including, for example, a touchscreen, touchpad, keyboard, mouse, camera, microphone, accelerometer, gyroscope, etc.; output devices 1007 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; memory devices 1008 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. Communication device 1009 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 10 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown. More or fewer devices may be implemented or have alternatively.

[0112] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 1009, or installed from a memory 1008, or installed from a ROM 1002. When the computer program is executed by the processor 1001, it performs the functions defined in the page element display method of embodiments of this disclosure.

[0113] It should be noted that the computer-readable medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having 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, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0114] In some implementations, clients and servers can communicate using any currently known or future-developed network protocol such as HTTP (Hypertext Transfer Protocol) and can interconnect with digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (“LANs”), wide area networks (“WANs”), the Internet (e.g., the Internet of Things), and end-to-end networks (e.g., ad hoc end-to-end networks), as well as any currently known or future-developed networks.

[0115] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0116] The aforementioned computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the method for displaying the aforementioned page elements.

[0117] Electronic devices can be programmed with computer program code in one or more programming languages ​​or combinations thereof to perform the operations of this disclosure. These programming languages ​​include, but are not limited to, object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can 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 can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0118] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0119] The units described in the embodiments of this disclosure can be implemented in software or hardware. The names of the units are not, in some cases, intended to limit the specific unit.

[0120] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), and so on.

[0121] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0122] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

[0123] Furthermore, while the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential order. In certain environments, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0124] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A method for detecting oscillation signals, characterized in that, include: Obtain time-domain voltage signals from the target power system; Time-frequency analysis is performed on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; The first time-frequency representation complex matrix is ​​rearranged in time and frequency to obtain a second time-frequency representation complex matrix. The energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix. A time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix. Instantaneous frequency spectral lines are extracted from the time-frequency representation spectrum, and instantaneous frequency identification is performed on the instantaneous frequency spectral lines to obtain the instantaneous frequency values ​​of the instantaneous frequency spectral lines; Based on the instantaneous frequency value, it is determined whether there are harmonics and / or interharmonics in the time-domain voltage signal. In response to the presence of harmonics and / or interharmonics in the time-domain voltage signal, it is determined that there is an oscillation signal in the target power system.

2. The method according to claim 1, characterized in that, After determining that an oscillation signal exists in the target power system, the method further includes: The time period value of the instantaneous frequency spectrum corresponding to the harmonics and / or interharmonics is obtained by identifying the time period of the instantaneous frequency spectrum. Output the instantaneous frequency value and the time period corresponding to the harmonic and / or interharmonic.

3. The method according to claim 1, characterized in that, The time-frequency analysis of the time-domain voltage signal based on time-frequency transformation yields a first time-frequency representation complex matrix, including: Based on the mother wavelet function, a family of wavelet functions controlled by scale and time parameters is constructed. The wavelet function family and the time-domain voltage signal are subjected to an inner product operation under scaling and time shifting. The time-domain voltage signal is then projected onto the wavelet function family to obtain a continuous wavelet transform complex matrix, which serves as the first time-frequency representation complex matrix.

4. The method according to claim 1, characterized in that, The step of performing time-frequency rearrangement on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix, and generating a time-frequency representation spectrum based on the second time-frequency representation complex matrix, includes: The first time-frequency representation complex matrix is ​​sharpened based on wavelet synchronous compression transform to obtain the second time-frequency representation complex matrix. The time-frequency representation spectrum is generated based on the second time-frequency representation complex matrix.

5. The method according to claim 1, characterized in that, The step of extracting instantaneous frequency spectral lines from the time-frequency representation spectrum includes iteratively performing the following operations until the number of instantaneous frequency spectral lines extracted from the time-frequency representation spectrum equals a number threshold: Extract the time-frequency ridge line with the strongest energy from the current time-frequency representation spectrum as the instantaneous frequency spectrum line; In the second time-frequency representation complex matrix, the values ​​of the complex matrix elements corresponding to the frequency position of the extracted instantaneous frequency spectrum line and the neighborhood are set to zero, and the second time-frequency representation complex matrix is ​​updated. The current time-frequency representation spectrum is updated based on the updated second time-frequency representation complex matrix.

6. The method according to claim 1, characterized in that, The step of determining whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value includes: Determine the relationship between the instantaneous frequency value and the frequency threshold; In response to the instantaneous frequency value being an integer multiple of the frequency threshold, it is determined that harmonics exist in the time-domain voltage signal; In response to the instantaneous frequency value being a non-integer multiple of the frequency threshold, it is determined that an interharmonic exists in the time-domain voltage signal.

7. An oscillation signal detection device, characterized in that, include: The time-domain voltage signal acquisition module is configured to acquire time-domain voltage signals from the target power system; The time-frequency analysis module is configured to perform time-frequency analysis on the time-domain voltage signal based on time-frequency transformation to obtain a first time-frequency representation complex matrix; The time-frequency representation spectrum determination module is configured to perform time-frequency rearrangement on the first time-frequency representation complex matrix to obtain a second time-frequency representation complex matrix, wherein the energy concentration of the time-frequency representation of the second time-frequency representation complex matrix is ​​higher than that of the first time-frequency representation complex matrix, and generate a time-frequency representation spectrum based on the second time-frequency representation complex matrix; The instantaneous frequency spectrum analysis module is configured to extract instantaneous frequency spectrum lines from the time-frequency representation spectrum, perform instantaneous frequency identification on the instantaneous frequency spectrum lines, and obtain the instantaneous frequency value of the instantaneous frequency spectrum lines. The oscillation phenomenon determination module is configured to determine whether harmonics and / or interharmonics exist in the time-domain voltage signal based on the instantaneous frequency value, and to determine that an oscillation signal exists in the target power system in response to the presence of harmonics and / or interharmonics in the time-domain voltage signal.

8. An electronic device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, It stores a computer program / instruction thereon, which, when executed by a processor, implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that, Includes a computer program / instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 6.

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