Broadband oscillation signal detection processing method and device

Abstract

The invention provides a broadband oscillation signal detection processing method and device, and the method comprises the steps: obtaining a corresponding three-phase voltage and current instantaneous value sequence of an initial broadband oscillation signal under a three-phase static coordinate system, carrying out the coordinate transformation processing of the three-phase voltage and current instantaneous value sequence, and obtaining a target signal sequence under a synchronous rotating coordinate system; compressing the target signal sequence to obtain a compressed signal sequence, marking a time mark on the compressed signal sequence, and sending the compressed signal sequence to a master station; performing frequency spectrum reconstruction processing on the compressed signal sequence marked with the time mark based on a sparsity self-adaptive matching pursuit algorithm operated in the master station to obtain a frequency spectrum signal reconstruction sequence; and performing interpolation correction and inverse coordinate transformation processing on the frequency spectrum signal reconstruction sequence to obtain a target broadband oscillation signal under the three-phase static coordinate system. According to the method provided by the invention, the detection accuracy of the broadband oscillation signal is effectively improved, and meanwhile, the storage and transmission load of the broadband oscillation signal is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power system analysis, and in particular to a method and device for detecting and processing a broadband oscillation signal, and also to an electronic device, a non-transient computer-readable storage medium, and a computer program product. Background Art

[0002] In recent years, with the vigorous development of a high proportion of renewable energy, the power electronics level of the system has gradually increased. The dynamic interaction between power electronic devices or between them and the network may induce broadband oscillation problems, such as multiple occurrences of 25Hz oscillation, 3~12Hz oscillation, and 15-85Hz oscillation. Such oscillation problems may induce a series of problems such as new energy units disconnecting from the grid, resonance of thermal power units, overvoltage / overcurrent of equipment, etc., which seriously affect the quality of power and threaten the safe and stable operation of the power system. In order to avoid further propagation and deterioration of oscillation, it is necessary to locate the disturbance source in time and perform emergency control to restore system stability. Accurate detection of oscillation signals is the basis for locating and analyzing disturbance sources. The current broadband oscillation voltage and current show characteristics such as wide bandwidth and time-varying amplitude, which puts forward requirements for high sampling rate, high frequency resolution, fast response speed and accuracy for the existing harmonic detection system, and brings huge load to data storage and transmission.

[0003] According to the data source, the existing broadband oscillation harmonic signal detection methods mainly include two categories: oscillation detection methods based on the instantaneous value data of the substation and oscillation detection methods based on the synchronous phasor of the master station. Taking the instantaneous value data of the substation as the analysis object has the advantages of low theoretical difficulty, wide measurement frequency band and high measurement accuracy, but it also has many defects. At present, the sampling frequency of the instantaneous value sequence of the substation is generally high (1200Hz, 9600Hz, 24kHz), which brings extremely high calculation load to the substation; at the same time, the instantaneous value data can only be obtained from the substation, and it is impossible to detect and analyze the propagation and development process of broadband from a global perspective. Due to the limitation of transmission bandwidth, the existing synchronous phasor measurement unit (PMU) can only upload the sub / supersynchronous oscillation identification results with the largest amplitude to the wide area measurement system (WAMS) master station, and can only detect and analyze subsynchronous oscillation signals below 50Hz, and the detection accuracy is low, and the storage and transmission load of broadband oscillation signals is high. Therefore, how to design an effective broadband oscillation signal detection and processing solution has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present invention provides a wideband oscillation signal detection and processing method, which is used to solve the defect that the wideband oscillation signal detection scheme in the prior art has high limitations, resulting in poor actual detection accuracy.

[0005] The present invention provides a method for detecting and processing a broadband oscillation signal, comprising: Obtaining a three-phase voltage and current instantaneous value sequence corresponding to the initial wide-band oscillation signal in a three-phase stationary coordinate system, performing coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system; compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to the master station after adding a time stamp; Based on the sparsity adaptive matching pursuit algorithm running in the master station, the spectrum of the compressed signal sequence marked with the time mark is reconstructed to obtain the spectrum signal reconstruction sequence; The frequency spectrum signal reconstruction sequence is subjected to interpolation correction and inverse coordinate transformation processing to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0006] According to a wide-band oscillation signal detection and processing method provided by the present invention, compressing the target signal sequence to obtain a compressed signal sequence specifically includes: Performing windowing processing on the target signal sequence to obtain a windowed target signal sequence; The target signal sequence after the windowing process is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence; wherein the measurement matrix is ​​a binarized Gaussian random measurement matrix.

[0007] According to a broadband oscillation signal detection and processing method provided by the present invention, before compressing the target signal sequence after windowing based on a preset measurement matrix to obtain a corresponding compressed signal sequence, the method further includes: Generate a Gaussian random matrix with M rows and N columns; wherein M is the length of the compressed signal sequence after compression, N is the length of the original target signal sequence, and each original target signal sequence is a random number that obeys a standard normal distribution; binarize the Gaussian random matrix, set the elements in the Gaussian random matrix that are greater than a preset target value to 1, and set the elements in the Gaussian random matrix that are less than or equal to the target value to 0, to obtain a binarized Gaussian random measurement matrix.

[0008] According to a broadband oscillation signal detection and processing method provided by the present invention, the interpolation correction and inverse coordinate transformation processing of the spectrum signal reconstruction sequence are performed to obtain the target broadband oscillation signal in the three-phase stationary coordinate system, specifically including: Performing interpolation correction processing on the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system; The frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system are subjected to inverse coordinate transformation processing to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0009] According to a broadband oscillation signal detection and processing method provided by the present invention, the interpolation correction processing is performed on the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system, specifically including: An interpolation algorithm is used to perform interpolation correction on the signal reconstruction sequence to obtain the frequency, amplitude and phase of the broadband oscillation signal component in the synchronous rotating coordinate system.

[0010] According to a wideband oscillation signal detection and processing method provided by the present invention, the windowed target signal sequence is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence, specifically: the windowed target signal sequence is multiplied by the measurement matrix for compression to obtain a corresponding compressed signal sequence.

[0011] The present invention also provides a broadband oscillation signal detection and processing device, comprising: A coordinate transformation processing unit is used to obtain a three-phase voltage and current instantaneous value sequence corresponding to the initial wide-band oscillation signal in a three-phase stationary coordinate system, and to perform coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system; A compression processing unit, used for compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to the main station after adding a time stamp; A spectrum reconstruction processing unit, used for performing spectrum reconstruction processing on the compressed signal sequence marked with the time stamp based on the sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence; The interpolation correction processing unit is used to perform interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0012] According to a broadband oscillation signal detection and processing device provided by the present invention, the compression processing unit is specifically used for: Performing windowing processing on the target signal sequence to obtain a windowed target signal sequence; The target signal sequence after the windowing process is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence; wherein the measurement matrix is ​​a binarized Gaussian random measurement matrix.

[0013] According to a broadband oscillation signal detection and processing device provided by the present invention, before compressing the target signal sequence after windowing based on a preset measurement matrix to obtain a corresponding compressed signal sequence, it also includes: Gaussian random measurement matrix building block for: Generate a Gaussian random matrix with M rows and N columns; wherein M is the length of the compressed signal sequence after compression, N is the length of the original target signal sequence, and each original target signal sequence is a random number that obeys a standard normal distribution; binarize the Gaussian random matrix, set the elements in the Gaussian random matrix that are greater than a preset target value to 1, and set the elements in the Gaussian random matrix that are less than or equal to the target value to 0, to obtain a binarized Gaussian random measurement matrix.

[0014] According to a broadband oscillation signal detection and processing device provided by the present invention, the interpolation correction processing unit is specifically used for: Performing interpolation correction processing on the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system; The frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system are subjected to inverse coordinate transformation processing to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0015] According to a broadband oscillation signal detection and processing device provided by the present invention, the interpolation correction processing of the spectrum signal reconstruction sequence is performed to obtain the frequency, amplitude and phase of the broadband oscillation signal component corrected in the synchronous rotating coordinate system, specifically including: An interpolation algorithm is used to perform interpolation correction on the signal reconstruction sequence to obtain the frequency, amplitude and phase of the broadband oscillation signal component in the synchronous rotating coordinate system.

[0016] According to a wideband oscillation signal detection and processing device provided by the present invention, the windowed target signal sequence is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence, specifically: the windowed target signal sequence is multiplied by the measurement matrix to obtain a corresponding compressed signal sequence.

[0017] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the wide-band oscillation signal detection and processing method as described in any one of the above items is implemented.

[0018] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for detecting and processing a broadband oscillation signal as described in any one of the above items is implemented.

[0019] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for detecting and processing a broadband oscillation signal as described in any one of the above items is implemented.

[0020] The broadband oscillation signal detection and processing method provided by the present invention obtains a three-phase voltage and current instantaneous value sequence corresponding to an initial broadband oscillation signal in a three-phase stationary coordinate system, performs coordinate transformation processing on the three-phase voltage and current instantaneous value sequence, obtains a target signal sequence in a synchronous rotating coordinate system, compresses the target signal sequence to obtain a compressed signal sequence, and sends the compressed signal sequence to a master station after time stamping, performs spectrum reconstruction processing on the compressed signal sequence after time stamping based on a sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence, performs interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system, which effectively improves the detection accuracy of broadband oscillation signals and reduces the load of broadband oscillation signal storage and transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a flow chart of the broadband oscillation signal detection and processing method provided by the present invention.

[0023] Figure 2 It is a schematic diagram of the instantaneous value waveform of the instantaneous value sequence of the A-phase current provided by the present invention.

[0024] Figure 3 It is a schematic diagram of the A-phase current amplitude spectrum provided by the present invention.

[0025] Figure 4 This is the x-axis current amplitude spectrum provided by the present invention.

[0026] Figure 5 It is a schematic diagram of some elements of the binarized Gaussian random measurement matrix provided by the present invention.

[0027] Figure 6 It is a structural schematic diagram of a broadband oscillation signal detection and processing device provided by the present invention.

[0028] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Combine the following Figure 1-Figure 7 The broadband oscillation signal detection and processing method and device of the present invention are described, and the embodiments thereof are described in detail.

[0031] The following is a detailed description of an embodiment of the broadband oscillation signal detection and processing method according to the present invention. Figure 1 As shown, it is one of the flow charts of the broadband oscillation signal detection and processing method provided by the present invention, and the specific implementation process includes the following steps: Step 101: Obtain a three-phase voltage and current instantaneous value sequence corresponding to an initial wide-band oscillation signal in a three-phase stationary coordinate system, perform coordinate transformation processing on the three-phase voltage and current instantaneous value sequence, and obtain a target signal sequence in a synchronous rotating coordinate system.

[0032] In an embodiment of the present invention, the three-phase voltage and current instantaneous value sequence can be subjected to synchronous coordinate transformation processing to transform the three-phase voltage and current instantaneous value sequence from a three-phase stationary coordinate system to a synchronous rotating coordinate system, and obtain a target signal sequence in the synchronous rotating coordinate system. When transforming the three-phase stationary coordinate system to the synchronous rotating coordinate system, the reference frequency of the rotating coordinate system is the fundamental frequency, which can be obtained by a phase-locked loop or other frequency measurement means. When transforming the three-phase voltage and current instantaneous value sequence sampled by the substation to the synchronous rotating coordinate system, the frequency coupling characteristics of sub / supersynchronous oscillations can be used to reduce the sparsity of the initial wide-band oscillation signal in the synchronous rotating coordinate system, thereby improving the accuracy of reconstruction. For example, specifically: suppose the three-phase voltage instantaneous value sequence in the power grid is , and the coordinate transformation matrix D is used to obtain the voltage sequence in the synchronous rotating coordinate system: in, , , They are the instantaneous value sequences of three-phase voltages in the abc coordinate system respectively; , They are synchronously rotating coordinate systems ( xy coordinate system) x axis, y The instantaneous value sequence of shaft voltage. The coordinate transformation matrix is ​​as follows: in, As the reference angular velocity of the synchronously rotating coordinate system, the fundamental angular velocity is used here (120*pi rad / s is used for a system with a rated frequency of 60 Hz, and 100*pi rad / s is used for a system with a rated frequency of 50 Hz). t is the sequence sampling time.

[0033] Step 102: compress the target signal sequence to obtain a compressed signal sequence, and then time-stamp the compressed signal sequence and send it to the main station.

[0034] In an embodiment of the present invention, the target signal sequence may be windowed to obtain a windowed target signal sequence, and then the windowed target signal sequence may be compressed using a measurement matrix to obtain a corresponding compressed signal sequence. The measurement matrix is ​​a binary Gaussian random measurement matrix. Then, the compressed compressed signal sequence is time-stamped and uploaded from the substation to the main station. xy The shaft voltage / current sequence (i.e., the target signal sequence) is compressed. Compared with the traditional Gaussian random matrix, the binarized Gaussian random measurement matrix can significantly reduce the storage and computing load, while ensuring that the compressed signal sequence can completely retain the original information. Since broadband oscillation signals are generally sparse in the frequency domain, the present invention uses compressed sensing technology to compress the three-phase voltage and current instantaneous value sequence in the synchronous phasor measurement device in the substation and then transmit it to the main station; the main station summarizes the compressed signal sequences from different substations at the same time according to the time scale, and then reconstructs the spectrum for subsequent spectrum or other analysis. This not only reduces the demand for signal transmission bandwidth, but also enables modal analysis from a global perspective.

[0035] It should be noted that before the target signal sequence after windowing is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence, it also includes: generating a Gaussian random matrix with M rows and N columns; wherein M is the length of the compressed signal sequence after compression, N is the length of the original target signal sequence, and each original target signal sequence is a random number that obeys a standard normal distribution; binarizing the Gaussian random matrix, setting elements in the Gaussian random matrix that are greater than a preset target value to 1, and setting elements in the Gaussian random matrix that are less than or equal to the target value to 0, to obtain a binarized Gaussian random measurement matrix. The target signal sequence after windowing is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence, specifically: multiplying the target signal sequence after windowing with the measurement matrix for compression to obtain a corresponding compressed signal sequence. Among them, the specific implementation method of the binarized random measurement matrix is: first generate a Gaussian random matrix with M rows and N columns, where M is the length of the compressed signal sequence after compression, N is the length of the original target signal sequence, and each original target signal sequence is a random number that obeys the standard normal distribution; then binarize the Gaussian random matrix, set the elements greater than the preset target value (such as 0.5) to 1, and set the elements less than or equal to the target value (such as 0.5) to 0, to obtain a binarized Gaussian random measurement matrix A; finally compress the target signal sequence x to obtain the compressed compressed signal sequence y: For example, the present invention performs synchronous rotating coordinate transformation through substation sampling. Assuming that the system does not have three-phase asymmetry, the substation samples the three-phase voltage and current instantaneous value sequence, the sampling point is N, and the sampling rate is 1 / Ts. At this time, the total dimension of the three-phase voltage and current instantaneous value sequence is 6*N, and the following measurement matrix is ​​used to transform it to the xy coordinate system (i.e., the synchronous rotating coordinate system): in, is the fundamental frequency, which can be obtained through a phase-locked loop. Assuming that a single-mode equal-amplitude oscillation signal appears in the power grid, the three-phase voltage and current instantaneous value sequence can be expressed as follows: Among them, 0, -, + represent the corresponding synchronous component, sub-synchronous component, and super-synchronous component respectively; the reference directions of the three frequency components are consistent. U and I are the voltage and current amplitudes, and are the initial phases of voltage and current respectively. is the torsional vibration frequency.

[0036] After synchronous coordinate transformation and subtracting the average value, xyThe AC component of the voltage instantaneous value sequence signal in the coordinate system becomes: Among them, Δ represents the deviation from the DC component, that is, the AC component of the voltage instantaneous value sequence signal.

[0037] It can be seen that the coupled sub-supersynchronous oscillation signal (frequency is symmetric about the fundamental wave) becomes a sub-synchronous component of the same frequency after coordinate transformation, and the sparsity of the oscillation signal is significantly reduced. This coupling also exists in the high-frequency component, but the frequency of the coupled pair of high-frequency components is is the positive sequence component, and the frequency is is a negative sequence component, which also has the above characteristics after synchronous rotation coordinate transformation. At the same time, the fundamental wave accounts for a high proportion of the sparsity of the original signal, which is meaningless for broadband oscillation detection itself. Therefore, after filtering out the fundamental wave, the sparsity is significantly reduced again, and the accuracy of compression / reconstruction can be significantly improved. The target signal sequence in the xy coordinate system (the total dimension is 4*N at this time) is windowed (that is, a Hanning window is added), and compressed using a 0 / 1 random measurement matrix. The dimension of the compressed signal sequence becomes 4*M, and the compressed signal sequence is time-stamped and sent to the master station.

[0038] The 0 / 1 random measurement matrix is ​​a Gaussian random matrix (dimension is M*N, M / N is the compression ratio) that is binarized, where values ​​less than the target value (such as 0.5) are converted to 0, and values ​​less than the target value (such as 0.5) are converted to 1. Each element in the Gaussian random matrix is ​​a random number that follows a standard normal distribution.

[0039] The method of the present invention can significantly reduce the memory used for storing random measurement matrices and the computational load. Especially in high sampling rate measurements, an integer matrix of M*9600 that can be sparsely stored has obvious advantages in storage and computation compared to an M*9600 float matrix. In the compression process, that is, in the calculation of the compression matrix*original sequence, the 0 / 1 random measurement matrix is ​​essentially addition rather than multiplication, which significantly improves the computational efficiency compared to Gaussian random matrix compression or direct discrete Fourier transform (DFT) processing.

[0040] Step 103: Perform spectrum reconstruction processing on the compressed signal sequence marked with the time stamp based on the sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence.

[0041] In the embodiment of the present invention, the compressed signal sequence sent by the substation is received by the master station, and the spectrum, i.e., the spectrum signal reconstruction sequence, is reconstructed by using the sparsity adaptive matching pursuit algorithm, so that the fence effect can be alleviated by interpolation correction later, and the frequency, amplitude and phase of the oscillation component in the synchronous rotating coordinate system are obtained. Finally, the frequency, amplitude and inverse of the oscillation component in the above synchronous rotating coordinate system are transformed to the three-phase stationary coordinate system.

[0042] Step 104 : performing interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0043] In an embodiment of the present invention, the spectrum signal reconstruction sequence can be interpolated and corrected to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system. The frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system are subjected to inverse coordinate transformation to obtain the target broadband oscillation signal in the three-phase stationary coordinate system. Among them, the interpolation and correction processing of the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system, the corresponding specific implementation process includes: using an interpolation algorithm to interpolate and correct the signal reconstruction sequence to obtain the frequency, amplitude and phase of the broadband oscillation signal component in the synchronous rotating coordinate system. It should be noted that the spectrum reconstructed using the sparsity adaptive matching pursuit algorithm is corrected by the master station to reduce the fence effect and improve the accuracy of the estimation of the frequency, amplitude and phase of the oscillation component. The specific implementation method is: the reconstructed spectral signal reconstructed sequence is an N-dimensional vector, in which the non-zero elements (sparseness) are adaptively obtained according to the compressed signal sequence after compression and the allowable error. Therefore, the spectral line with the local maximum amplitude in the high probability spectrum and the spectral lines on both sides thereof can be used to calculate the correction coefficient and correct the frequency, amplitude and phase information of the oscillation component.

[0044] The master station uses a sparse adaptive matching pursuit algorithm to reconstruct the spectrum, and uses the following interpolation algorithm to correct the error caused by the fence effect, so as to obtain the frequency, amplitude and phase information of the oscillation component whose amplitude exceeds the set threshold, which is used for subsequent oscillation source positioning and emergency control.

[0045] For example, let the spectrum obtained after reconstruction be S[z]. Since the harmonic frequency is inconsistent with the discrete spectrum line frequency, it is necessary to find the actual harmonic frequency (the peak value of the continuous spectrum line) through interpolation. Z is the spectrum line number with the largest amplitude near the harmonic frequency, and the compensation parameter is δ for: in, is the amplitude of the Zth spectral line.

[0046] Get frequency , Amplitude , Phase Estimated value: in, N is the number of signal sampling points, T s is the sampling time, δ is the compensation parameter.

[0047] The broadband oscillation signal detection and processing method of the present invention is as follows: first, the synchronous phasor measurement device preset in the substation collects the three-phase voltage and current instantaneous value sequence corresponding to the broadband oscillation signal, transforms the three-phase voltage and current instantaneous value sequence corresponding to the broadband oscillation signal from the three-phase stationary coordinate system to the synchronous rotating coordinate system, obtains the target signal sequence in the synchronous rotating coordinate system, and adds the Hanning window to the target signal sequence, and filters out the fundamental wave by subtracting the mean; then, the measurement matrix is ​​used for compression, that is, the target signal sequence is compressed by the measurement matrix and uploaded to the main station after being marked with a time stamp; the main station uses a sparse adaptive matching pursuit algorithm to reconstruct the spectrum, and uses an interpolation algorithm formula to correct and estimate the frequency, amplitude, and phase of the oscillation component, alleviate spectrum leakage and fence effect, so as to meet the needs of subsequent oscillation source positioning and emergency control. The method can be deployed in a real-time monitoring system for a power grid (i.e., a real-time monitoring device for a power grid), realizes accurate detection of broadband oscillation signals, and reduces the load of oscillation signal storage and transmission, providing a basis for emergency control and subsequent analysis of oscillation. The real-time monitoring system for a power grid or the real-time monitoring device for a power grid includes a substation and a main station. The synchronized phasor measurement device (ie, PMU device) is arranged in the substation.

[0048] In a complete embodiment of the present invention, the implementation of the proposed wide-band oscillation signal detection and transmission framework will be specifically demonstrated below in conjunction with a set of oscillated current sequences.

[0049] s1) Sampling and synchronous rotating coordinate transformation through the substation: Assume that a multi-modal broadband oscillation signal appears on a certain line of the power grid, where the amplitude and phase information of each frequency in the A-phase current are shown in the following figure: Table 1 Oscillation signal frequency, amplitude, and phase

[0050] Set the sampling rate to 9600Hz and the sampling window length to 1s. The sequence and spectrum are as follows Figure 2 and Figure 3As shown in the figure, the broadband oscillation signal fluctuates violently in the time domain, and the fundamental wave occupies the main part, that is, most of the information in the three-phase voltage and current instantaneous value sequence (time domain) corresponding to the broadband oscillation signal is invalid information. And due to the multimodal characteristics of the broadband oscillation signal itself and the spectrum leakage problem, the sparsity of the broadband oscillation signal in the frequency domain is not ideal, especially in the range of 0~100Hz. The original three-phase voltage and current instantaneous value sequence is transformed into a synchronous rotating coordinate system, and the spectrum of the x-axis signal is as follows Figure 4 As shown in the figure, the original 10 harmonic components are reduced to 5, and the fundamental component with the highest proportion becomes a DC component and is filtered out, and the sparsity of the broadband oscillation signal in the frequency domain is greatly improved. It should be noted that Figure 3 The sub-graph shown in the upper right corner with a horizontal coordinate of 0-100 and a vertical coordinate of 0-0.4 corresponds to Figure 3 The horizontal axis in the middle is an enlarged view of the first 0-100 part of 0-1000. Similarly, it should be noted that Figure 4 The sub-graph shown in the upper middle side with a horizontal coordinate of 0-40 and a vertical coordinate of 0-0.5 corresponds to Figure 4 The horizontal axis in the middle is an enlarged view of the first 0-40 part of 0-1000.

[0051] s2) The substation in the same freight line adds a Hanning window to the xy axis sequence and multiplies it with the measurement matrix for compression processing, and then adds a time stamp to send it to the main station: The Hanning window w[n] formula is as follows, and the windowing can be completed by multiplying it with the original target signal sequence: in, N w is the Hanning window length, which is consistent with the number of signal sampling points. w [n] is the value of the nth element of the Hanning window.

[0052] The windowed target signal sequence is multiplied by the measurement matrix. It should be noted that the length M of the compressed signal sequence after compression needs to meet the following conditions: in, K is the sparsity, in order to fully retain the information. Here we choose M The length is 150, so the compression ratio is 0.0156.

[0053] The measurement matrix here is a binary Gaussian random measurement matrix, such as Figure 5 A portion of the elements of the measurement matrix is ​​shown.

[0054] s3) The spectrum is reconstructed through the master station's matching pursuit algorithm based on sparsity adaptation. Since the broadband oscillation signal is sparse in the frequency domain, the sparse basis is selected as the DFT matrix. The reconstruction algorithm is as follows: In each iteration, the inner product between the measurement matrix A and the residual r (initialized as the compressed signal sequence after compression) is first calculated, and K atoms with the largest correlation coefficient are selected (K is the current sparsity or the initialization sparsity), and together with the support set obtained in the previous iteration, they constitute a candidate set, and there are 2K atoms in the candidate set; then the candidate set is used to estimate the sparsity coefficient, and the most relevant K atoms are selected from them, and the new residual is calculated; if the new residual is not less than the residual of the previous iteration, it means that the signal reconstruction effect is not good, and the step size is superimposed on the current sparsity as the new sparsity. Repeat the iterative process multiple times or reach the stopping condition, and finally use the selected atoms to reconstruct the signal (that is, the spectrum signal reconstruction sequence).

[0055] The spectrum signal reconstruction sequence of the xy axis is corrected by interpolation algorithm to obtain the frequency, amplitude and phase of the corrected oscillation component in the xy coordinate system, and then it is inversely transformed to the abc coordinate system (i.e. the three-phase stationary coordinate system).

[0056] In addition, the following compares the relative errors of the oscillation component frequency, amplitude, and phase using the compressed sampling matching pursuit algorithm CoSaMP, the sparsity adaptive matching pursuit algorithm SAMP but without coordinate transformation, and the sparsity adaptive matching pursuit algorithm with coordinate transformation: Table 2 Summary of relative errors after reconstruction

[0057] As can be seen from the table above, the amplitude and phase errors of the reconstruction using the compressed sampling matching pursuit algorithm exceed the requirements at some frequencies. The reason for the analysis may be that the algorithm requires the sparsity to be given in advance, but the sparsity cannot be predicted in actual oscillations, so it may not be possible to accurately reconstruct the signal. Regardless of whether the coordinate transformation is performed, the matching pursuit algorithm with adaptive sparsity can meet the national standard requirements. In addition, since the fundamental wave is filtered out after the coordinate transformation and the sparsity of the signal in the frequency domain is significantly reduced, the result of reconstructing the sequence compressed after the coordinate transformation is more accurate.

[0058] The present invention proposes a broadband oscillation signal detection and transmission framework based on compressed sensing, which includes two parts: data processing and compression of the substation and reconstruction and interpolation correction of the main station. The data processing of the substation mainly includes two parts: synchronous rotating coordinate transformation and windowing processing. Windowing can alleviate the common spectrum leakage phenomenon in Fourier analysis, while the synchronous rotating coordinate transformation utilizes the coupling characteristics of sub / supersynchronous oscillations in broadband oscillations and filters out the fundamental wave, which can significantly reduce the sparsity and improve the reconstruction effect of the main station. In addition, the substation also uses a binary random measurement matrix for compression, which can significantly reduce the amount of calculation in the compression process compared to non-binarized matrices such as Gaussian random matrices. Reduce computing load. The main station includes a matching pursuit algorithm that uses sparsity adaptation, and interpolates and corrects the reconstructed spectrum to alleviate the fence effect. Compared with the traditional detection method based on the instantaneous value sequence of the substation, this framework avoids large amounts of local calculations or channel occupancy, and instead transfers the calculation workload to the master station for global analysis of the oscillation. It also reduces the transmission bandwidth requirements and storage requirements of the oscillation signal through compression, and can be applied to a broadband oscillation detection framework, providing a basis for subsequent emergency control.

[0059] The broadband oscillation signal detection and processing method provided by the present invention obtains a three-phase voltage and current instantaneous value sequence corresponding to an initial broadband oscillation signal in a three-phase stationary coordinate system, performs coordinate transformation processing on the three-phase voltage and current instantaneous value sequence, obtains a target signal sequence in a synchronous rotating coordinate system, compresses the target signal sequence to obtain a compressed signal sequence, and sends the compressed signal sequence to a master station after time stamping, performs spectrum reconstruction processing on the compressed signal sequence after time stamping based on a sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence, performs interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system, which effectively improves the detection accuracy of broadband oscillation signals and reduces the load of broadband oscillation signal storage and transmission.

[0060] The following is a description of the broadband oscillation signal detection and processing device provided by the present invention. The broadband oscillation signal detection and processing device described below and the broadband oscillation signal detection and processing method described above can be referred to each other. Figure 6 As shown, it is a schematic diagram of the structure of the wide-band oscillation signal detection and processing device provided by the present invention. The wide-band oscillation signal detection and processing device of the present invention specifically includes the following parts: The coordinate transformation processing unit 601 is used to obtain a three-phase voltage and current instantaneous value sequence corresponding to the initial wide-band oscillation signal in a three-phase stationary coordinate system, and perform coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system.

[0061] The compression processing unit 602 is used to perform compression processing on the target signal sequence to obtain a compressed signal sequence, and then send the compressed signal sequence to the main station after adding a time stamp.

[0062] The spectrum reconstruction processing unit 603 is used to perform spectrum reconstruction processing on the time-stamped compressed signal sequence based on the sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstructed sequence.

[0063] The interpolation correction processing unit 604 is used to perform interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0064] According to a broadband oscillation signal detection and processing device provided by the present invention, the compression processing unit is specifically used for: Performing windowing processing on the target signal sequence to obtain a windowed target signal sequence; The target signal sequence after the windowing process is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence; wherein the measurement matrix is ​​a binarized Gaussian random measurement matrix.

[0065] According to a broadband oscillation signal detection and processing device provided by the present invention, before compressing the target signal sequence after windowing based on a preset measurement matrix to obtain a corresponding compressed signal sequence, it also includes: Gaussian random measurement matrix building block for: Generate a Gaussian random matrix with M rows and N columns; wherein M is the length of the compressed signal sequence after compression, N is the length of the original target signal sequence, and each original target signal sequence is a random number that obeys a standard normal distribution; binarize the Gaussian random matrix, set the elements in the Gaussian random matrix that are greater than a preset target value to 1, and set the elements in the Gaussian random matrix that are less than or equal to the target value to 0, to obtain a binarized Gaussian random measurement matrix.

[0066] According to a broadband oscillation signal detection and processing device provided by the present invention, the interpolation correction processing unit is specifically used for: Performing interpolation correction processing on the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system; The frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system are subjected to inverse coordinate transformation processing to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

[0067] According to a broadband oscillation signal detection and processing device provided by the present invention, the interpolation correction processing of the spectrum signal reconstruction sequence is performed to obtain the frequency, amplitude and phase of the broadband oscillation signal component corrected in the synchronous rotating coordinate system, specifically including: An interpolation algorithm is used to perform interpolation correction on the signal reconstruction sequence to obtain the frequency, amplitude and phase of the broadband oscillation signal component in the synchronous rotating coordinate system.

[0068] According to a wideband oscillation signal detection and processing device provided by the present invention, the windowed target signal sequence is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence, specifically: the windowed target signal sequence is multiplied by the measurement matrix to obtain a corresponding compressed signal sequence.

[0069] The broadband oscillation signal detection and processing device provided by the present invention obtains a three-phase voltage and current instantaneous value sequence corresponding to an initial broadband oscillation signal in a three-phase stationary coordinate system, performs coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system, compresses the target signal sequence to obtain a compressed signal sequence, and sends the compressed signal sequence to a master station after time stamping, performs spectrum reconstruction processing on the compressed signal sequence after time stamping based on a sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence, performs interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system, which effectively improves the detection accuracy of broadband oscillation signals and reduces the load of broadband oscillation signal storage and transmission.

[0070] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7As shown, the electronic device (i.e., a power grid real-time monitoring system or a power grid real-time monitoring device) may include: a processor (processor) 701, a communication interface (Communications Interface) 704, a memory (memory) 702 and a communication bus 703, wherein the processor 701, the communication interface 704, and the memory 702 communicate with each other via the communication bus 703. The processor 701 can call the logic instructions in the memory 702 to execute the broadband oscillation signal detection and processing method, which includes: obtaining a three-phase voltage and current instantaneous value sequence corresponding to the initial broadband oscillation signal in a three-phase stationary coordinate system, performing coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system; compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to the master station after time stamping; performing spectrum reconstruction processing on the compressed signal sequence after time stamping based on the sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence; performing interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain the target broadband oscillation signal in the three-phase stationary coordinate system.

[0071] In addition, the logic instructions in the above-mentioned memory 702 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.

[0072] On the other hand, the present application also provides a computer program product, which includes a computer program. The computer program can be stored on a computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the broadband oscillation signal detection and processing method provided by the above methods, which method includes: obtaining a three-phase voltage and current instantaneous value sequence corresponding to the initial broadband oscillation signal in a three-phase stationary coordinate system, performing coordinate transformation processing on the three-phase voltage and current instantaneous value sequence, and obtaining a target signal sequence in a synchronous rotating coordinate system; compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to a master station after time stamping; performing spectrum reconstruction processing on the compressed signal sequence after time stamping based on a sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence; performing interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain the target broadband oscillation signal in the three-phase stationary coordinate system.

[0073] On the other hand, the present application also provides a computer-readable storage medium, the computer-readable storage medium includes a stored program, wherein the program, when running, executes the broadband oscillation signal detection and processing method provided by the above-mentioned methods, the method comprising: obtaining a three-phase voltage and current instantaneous value sequence corresponding to the initial broadband oscillation signal in a three-phase stationary coordinate system, performing coordinate transformation processing on the three-phase voltage and current instantaneous value sequence, and obtaining a target signal sequence in a synchronous rotating coordinate system; compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to a master station after time stamping; performing spectrum reconstruction processing on the compressed signal sequence after time stamping based on a sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence; performing interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain the target broadband oscillation signal in the three-phase stationary coordinate system.

[0074] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0075] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for detecting and processing a broadband oscillation signal, characterized in that: include: Obtaining a three-phase voltage and current instantaneous value sequence corresponding to the initial wide-band oscillation signal in a three-phase stationary coordinate system, performing coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system; compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to the master station after adding a time stamp; Based on the sparsity adaptive matching pursuit algorithm running in the master station, the spectrum of the compressed signal sequence marked with the time mark is reconstructed to obtain the spectrum signal reconstruction sequence; The frequency spectrum signal reconstruction sequence is subjected to interpolation correction and inverse coordinate transformation processing to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

2. The method for detecting and processing a broadband oscillation signal according to claim 1, wherein: The compressing the target signal sequence to obtain a compressed signal sequence specifically includes: Performing windowing processing on the target signal sequence to obtain a windowed target signal sequence; The target signal sequence after the windowing process is compressed based on a preset measurement matrix to obtain a corresponding compressed signal sequence; wherein the measurement matrix is ​​a binarized Gaussian random measurement matrix.

3. The method for detecting and processing a broadband oscillation signal according to claim 2, wherein: Before compressing the windowed target signal sequence based on a preset measurement matrix to obtain a corresponding compressed signal sequence, the method further includes: Generate a Gaussian random matrix with M rows and N columns; wherein M is the length of the compressed signal sequence after compression, N is the length of the original target signal sequence, and each original target signal sequence is a random number that obeys a standard normal distribution; binarize the Gaussian random matrix, set the elements in the Gaussian random matrix that are greater than a preset target value to 1, and set the elements in the Gaussian random matrix that are less than or equal to the target value to 0, to obtain a binarized Gaussian random measurement matrix.

4. The method for detecting and processing a broadband oscillation signal according to claim 1, wherein: The interpolation correction and inverse coordinate transformation processing of the spectrum signal reconstruction sequence to obtain the target broadband oscillation signal in the three-phase stationary coordinate system specifically includes: Performing interpolation correction processing on the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system; The frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system are subjected to inverse coordinate transformation processing to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

5. The method for detecting and processing a broadband oscillation signal according to claim 4, wherein: The interpolation correction processing is performed on the spectrum signal reconstruction sequence to obtain the frequency, amplitude and phase of the corrected broadband oscillation signal component in the synchronous rotating coordinate system, specifically including: An interpolation algorithm is used to perform interpolation correction on the signal reconstruction sequence to obtain the frequency, amplitude and phase of the broadband oscillation signal component in the synchronous rotating coordinate system.

6. The method for detecting and processing a broadband oscillation signal according to claim 2, wherein: The compressing process is performed on the windowed target signal sequence based on a preset measurement matrix to obtain a corresponding compressed signal sequence, specifically: the windowed target signal sequence is multiplied by the measurement matrix to perform compression to obtain a corresponding compressed signal sequence.

7. A broadband oscillation signal detection and processing device, characterized in that: include: A coordinate transformation processing unit is used to obtain a three-phase voltage and current instantaneous value sequence corresponding to the initial wide-band oscillation signal in a three-phase stationary coordinate system, and to perform coordinate transformation processing on the three-phase voltage and current instantaneous value sequence to obtain a target signal sequence in a synchronous rotating coordinate system; A compression processing unit, used for compressing the target signal sequence to obtain a compressed signal sequence, and sending the compressed signal sequence to the main station after adding a time stamp; A spectrum reconstruction processing unit, used for performing spectrum reconstruction processing on the compressed signal sequence marked with the time stamp based on the sparsity adaptive matching pursuit algorithm running in the master station to obtain a spectrum signal reconstruction sequence; The interpolation correction processing unit is used to perform interpolation correction and inverse coordinate transformation processing on the spectrum signal reconstruction sequence to obtain a target broadband oscillation signal in the three-phase stationary coordinate system.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the wide-band oscillation signal detection and processing method according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the wide-band oscillation signal detection and processing method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the wide-band oscillation signal detection and processing method according to any one of claims 1 to 6 is implemented.

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