Synchronous waveform and broad spectrum phasor measurement method and device

Abstract

The present application relates to the technical field of power systems, and in particular to a synchronous waveform and wide-spectrum phasor measurement method and device, wherein the method includes: collecting three-phase analog voltage and current signals, and performing anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering; performing analog-to-digital conversion on the analog signals after filtering, and performing wide-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain wide-spectrum phasor measurement results; using a preset positioning system's pulse per second PPS signal to time the wide-spectrum phasor measurement results, and uploading the timed results to a master station to obtain the final results. Thus, the problem in the related art that there may be multiple modes in a broadband oscillation, resulting in the mutual influence of the spectrum between the multiple modes, reducing the accuracy of the wide-spectrum phasor measurement, and failing to meet the measurement requirements of the wide-spectrum phasor is solved.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a synchronous waveform and broad-spectrum phasor measurement method and device. Background Art

[0002] In the related technology, the commonly used PMU (phasor measurement unit) can realize the measurement of fundamental phasor based on DFT (Discrete Fourier transform), that is, the frequency of the signal component corresponding to the phasor is 50Hz, and an interharmonic phasor measurement method based on PMU phasor measurement values ​​and voltage and current sampling values ​​is proposed, which is used for monitoring wide-band oscillations of power systems by synchronous waveform and wide-spectrum phasor measurement.

[0003] However, in the related technology, since multiple modes may exist in broadband oscillations, the spectra of multiple modes affect each other, reducing the accuracy of wide-spectrum phasor measurement and failing to meet the measurement requirements of wide-spectrum phasors, which needs to be solved urgently. Summary of the invention

[0004] The present application provides a synchronous waveform and wide-spectrum phasor measurement method and device to solve the problems in the related art that due to the possibility of multiple modes in broadband oscillation, the spectrums of multiple modes influence each other, reducing the accuracy of wide-spectrum phasor measurement and failing to meet the measurement requirements of wide-spectrum phasors.

[0005] The first aspect of the present application provides a synchronous waveform and wide-spectrum phasor measurement method, including the following steps: collecting three-phase analog voltage and current signals, and performing anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering; performing analog-to-digital conversion on the analog signals after filtering, and performing wide-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain wide-spectrum phasor measurement results; using a preset positioning system's PPS (Pulse Per Second, pulse number per second) signal to time the wide-spectrum phasor measurement results, and uploading the timed results to a master station to obtain the final results.

[0006] Optionally, in one embodiment of the present application, uploading the timing result to the master station includes: uploading the timing result to the master station at preset time intervals. Optionally, in one embodiment of the present application, performing broad-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain a broad-spectrum phasor measurement result includes: calculating the broad-spectrum phasor based on a wavelet filter, wherein the wavelet filter is:

[0007]

[0008] Among them, a is the wavelet coefficient that can be adjusted adaptively, f cc is the filter center frequency, f s Signal sampling frequency, n is the sampling point number.

[0009] Optionally, in one embodiment of the present application, the calculation formula of the broad-spectrum phasor is:

[0010]

[0011] Among them, p ih (n) is the broad spectrum phasor value, and s(n) is the grid current signal containing fundamental and interharmonic / harmonic components.

[0012] Optionally, in one embodiment of the present application, the calculation of the broad-spectrum phasor based on the wavelet filter includes: generating sampling data using the sampling values ​​of the voltage and current waveforms of each phase; calculating the fundamental voltage and current vector based on the FFT (Fast Fourier transform) of one fundamental frequency, and substituting it into the wind turbine impedance model to obtain a real-time impedance model, and obtaining an aggregated impedance model based on the system topology; performing a broadband oscillation stability analysis of the system based on the aggregated impedance model, and estimating the broadband oscillation frequency value; calculating the initial broad-spectrum phasor value and the initial broad-spectrum frequency based on the broadband oscillation frequency value, and adjusting the wavelet coefficients based on the initial broad-spectrum phasor amplitude until the final broad-spectrum phasor and the final broad-spectrum frequency are obtained.

[0013] The second aspect of the present application provides a synchronous waveform and wide-spectrum phasor measurement device, including: a processing module, used to collect three-phase analog voltage and current signals, and perform anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering; a measurement module, used to perform analog-to-digital conversion on the analog signals after filtering, and perform wide-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain wide-spectrum phasor measurement results; a control module, used to use a pulse per second PPS signal of a preset positioning system to time the wide-spectrum phasor measurement results, and upload the timed results to a master station to obtain the final results.

[0014] Optionally, in one embodiment of the present application, the control module is further used to upload the timing result to the master station at preset time intervals.

[0015] Optionally, in one embodiment of the present application, the measurement module is further used to calculate the broad-spectrum phasor based on a wavelet filter, wherein the wavelet filter is:

[0016]

[0017] Among them, a is the wavelet coefficient that can be adjusted adaptively, fcc is the filter center frequency, f s Signal sampling frequency, n is the sampling point number.

[0018] Optionally, in one embodiment of the present application, the calculation formula of the broad-spectrum phasor is:

[0019]

[0020] Among them, p ih (n) is the broad spectrum phasor value, and s(n) is the grid current signal containing fundamental and interharmonic / harmonic components.

[0021] Optionally, in one embodiment of the present application, the calculation of the broad-spectrum phasor based on the wavelet filter includes generating sampling data using the sampling values ​​of the voltage and current waveforms of each phase, calculating the fundamental voltage and current vectors based on the fast Fourier transform FFT of one fundamental frequency, and substituting them into the wind turbine impedance model to obtain a real-time impedance model, and obtaining an aggregate impedance model based on the system topology, performing a broadband oscillation stability analysis of the system based on the aggregate impedance model, estimating the broadband oscillation frequency value, calculating the initial broad-spectrum phasor value and the initial broad-spectrum frequency based on the broadband oscillation frequency value, and adjusting the wavelet coefficients based on the initial broad-spectrum phasor amplitude until the final broad-spectrum phasor and the final broad-spectrum frequency are obtained.

[0022] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the synchronous waveform and wide-spectrum phasor measurement method as described in the above embodiment.

[0023] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the above-mentioned synchronous waveform and wide-spectrum phasor measurement method.

[0024] The embodiment of the present application can collect three-phase analog voltage and current signals, and perform anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering, thereby performing analog-to-digital conversion, and performing broad-spectrum phasor measurement based on an adaptive wavelet filter to obtain broad-spectrum phasor measurement results, and use the pulse number per second PPS signal of the positioning system to time the broad-spectrum phasor measurement results, and upload the timed results to the main station to obtain the final results, thereby effectively improving the stopband attenuation capability, suppressing mutual interference of the spectrum, and improving the measurement accuracy of the broad-spectrum phasor. Thus, the problem in the related art that there may be multiple modes in the broadband oscillation, resulting in the mutual influence of the spectrum between the multiple modes, reducing the accuracy of the broad-spectrum phasor measurement, and failing to meet the measurement requirements of the broad-spectrum phasor is solved.

[0025] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0027] Figure 1 A flowchart of a synchronous waveform and wide-spectrum phasor measurement method provided according to an embodiment of the present application;

[0028] Figure 2 This is a schematic diagram of the broad-spectrum phasor measurement principle of a specific embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of the synchronous waveform acquisition principle of a specific embodiment of the present application;

[0030] Figure 4 This is a flow chart of a broad-spectrum phasor measurement method based on an adaptive wavelet filter according to a specific embodiment of the present application;

[0031] Figure 5 It is a structural schematic diagram of a synchronous waveform and wide-spectrum phasor measurement device according to an embodiment of the present application;

[0032] Figure 6 Schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0034] The following describes the synchronous waveform and wide-spectrum phasor measurement method and device of the embodiment of the present application with reference to the accompanying drawings. In view of the related technology mentioned in the background technology center, due to the possibility of multiple modes in the broadband oscillation, the spectrum between the multiple modes affects each other, reducing the accuracy of the broadband phasor measurement, and failing to meet the measurement requirements of the broadband phasor, the present application provides a synchronous waveform and broadband phasor measurement method, in which three-phase analog voltage and current signals can be collected, and the three-phase analog voltage and current signals are subjected to anti-aliasing filtering to obtain the analog signal after filtering, thereby performing analog-to-digital conversion, and performing broadband phasor measurement based on an adaptive wavelet filter to obtain the broadband phasor measurement result, using the pulse number per second PPS signal of the positioning system to time the broadband phasor measurement result, and uploading the result after time service to the master station to obtain the final result, thereby effectively improving the stopband attenuation capability, suppressing the mutual interference of the spectrum, and improving the measurement accuracy of the broadband phasor. Thus, the related technology solves the problem that due to the possibility of multiple modes in the broadband oscillation, the spectrum between the multiple modes affects each other, reducing the accuracy of the broadband phasor measurement, failing to meet the measurement requirements of the broadband phasor, and the like.

[0035] Specifically, Figure 1 A schematic flow chart of a synchronous waveform and wide-spectrum phasor measurement method provided in an embodiment of the present application.

[0036] like Figure 1 As shown, the synchronous waveform and broad-spectrum phasor measurement method includes the following steps:

[0037] In step S101 , three-phase analog voltage and current signals are collected, and anti-aliasing filtering is performed on the three-phase analog voltage and current signals to obtain filtered analog signals.

[0038] It can be understood that the embodiment of the present application first performs synchronous waveform acquisition, that is, acquires three-phase analog voltage and current signals, and performs anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering, thereby improving the real-time performance of the acquired signals and improving the feasibility of wide-spectrum phasor measurement.

[0039] In step S102, analog-to-digital conversion is performed on the filtered analog signal, and broad-spectrum phasor measurement is performed based on a preset adaptive wavelet filter to obtain a broad-spectrum phasor measurement result.

[0040] It can be understood that the embodiment of the present application can perform analog-to-digital conversion on the analog signal after filtering, and perform wide-spectrum phasor measurement based on the adaptive wavelet filter in the following steps to obtain wide-spectrum phasor measurement results, thereby improving the real-time performance of power grid operation analysis and improving the measurement accuracy of wide-spectrum phasors.

[0041] As a possible way to achieve this, Figure 2 As shown, the embodiment of the present application first performs anti-aliasing filtering on the three-phase analog voltage and current signals, then performs analog-to-digital conversion on the filtered analog signals, and finally, performs wide-spectrum phasor measurement based on an adaptive wavelet filter to obtain wide-spectrum phasor measurement results. It should be noted that the wide-spectrum phasor measurement adopts a fixed-time measurement method similar to that of the PMU, that is, measurement is performed at regular intervals and the measurement results are uploaded. Unlike the synchronous waveform upload mode, there is no other upload mode for the wide-spectrum phasor measurement results.

[0042] In some embodiments, a grid current signal containing fundamental wave and interharmonic / harmonic components can be expressed as:

[0043]

[0044] Among them, f1, f ih and f s are the rated frequency, interharmonic / harmonic frequency and signal sampling frequency respectively, a1 and θ1 are the fundamental wave effective value and phase respectively, a ih (n) and θ ih (n) are the initial effective value and phase of the interharmonics, and n is the sampling point number.

[0045] in,

[0046]

[0047] Among them, p ih (n) is the interharmonic / harmonic phasor.

[0048] In order to estimate the broad-spectrum phasor, it is generally possible to consider using a bandpass finite impulse response filter. However, since the interharmonic / harmonic frequencies may take values ​​in a wide range from several Hz to several kHz, the center frequency parameters of the filter cannot be known in advance. In addition, since the interharmonics / harmonics may be suddenly generated after a disturbance in the system, the voltage and current signals may be discontinuous at this time, thereby reducing the measurement accuracy of the broad-spectrum phasor. Finally, since there may be multiple modes in the broadband oscillation, the spectra between the multiple modes will affect each other, reducing the measurement accuracy of the broad-spectrum phasor. Therefore, the embodiment of the present application solves the above problems through a broad-spectrum phasor measurement method based on an adaptive wavelet filter.

[0049] In one embodiment of the present application, a broad-spectrum phasor measurement is performed based on a preset adaptive wavelet filter to obtain a broad-spectrum phasor measurement result, including: calculating a broad-spectrum phasor based on a wavelet filter, wherein the wavelet filter is:

[0050]

[0051] Among them, a is the wavelet coefficient that can be adjusted adaptively, f cc is the filter center frequency, f s Signal sampling frequency, n is the sampling point number.

[0052] In one embodiment of the present application, the calculation formula of the broad spectrum phasor is:

[0053]

[0054] Among them, p ih (n) is the broad spectrum phasor value, and s(n) is the grid current signal containing fundamental and interharmonic / harmonic components.

[0055] The frequencies corresponding to the broad spectrum components can be calculated based on the following formula:

[0056]

[0057] In summary, the embodiment of the present application can effectively reduce the impact of harmonic components and phase calculation errors. By adjusting a and f cc The size of can improve the performance of the above wavelet filter, that is, change the accuracy of wide-spectrum phasor measurement.

[0058] It should be noted that, since the time when the multimodal component exists is later than the time when the signal is discontinuous (ie, the time when the oscillation occurs), there will be no contradiction in the adjustment of the wavelet coefficients.

[0059] Optionally, in one embodiment of the present application, a broad-spectrum phasor is calculated based on a wavelet filter, including: generating sampling data using the voltage and current waveform sampling values ​​of each phase; calculating the fundamental voltage and current vector based on a fast Fourier transform (FFT) of one fundamental frequency, and substituting it into the wind turbine impedance model to obtain a real-time impedance model, and obtaining an aggregate impedance model based on the system topology; performing a broadband oscillation stability analysis of the system based on the aggregate impedance model, and estimating the broadband oscillation frequency value; calculating the initial broad-spectrum phasor value and the initial broad-spectrum frequency based on the broadband oscillation frequency value, and adjusting the wavelet coefficient based on the initial broad-spectrum phasor amplitude until the final broad-spectrum phasor and the final broad-spectrum frequency are obtained.

[0060] In the actual implementation process, the broad-spectrum phasor measurement device designed in the embodiment of the present application is mainly used for the time harmonic / harmonic phasor measurement of broadband oscillation in the power system. Therefore, the f can be preset by using the online stability analysis result of broadband oscillation in the power system. cc Specifically, the impedance models of the main components in the power system are established.

[0061] For example, for a wind power grid-connected system, the impedance models of the wind turbine converter, transmission line and power grid can be established, which are set as Z C (U,I,f),ZL (f) and Z G (f), where the impedance model of the wind turbine converter is a function of the fundamental voltage U, fundamental current I and frequency f, and the impedance model of the transmission line Z L (f) and the impedance model Z of the power grid G (f) is a function of frequency f, wherein there are many ways to calculate the impedance model, which are not specifically limited here. It can be seen that the impedance model of the wind turbine converter is related to the operating conditions. Under real-time operation, voltage and current signals can be collected, and the fundamental voltage and current values ​​can be obtained based on the fast Fourier transform FFT calculation. After substituting them into the above impedance model, the impedance values ​​of the wind turbine converter at different frequencies can be obtained.

[0062] Next, after obtaining the impedance values ​​of different components, the aggregate impedance model can be established according to the topology. For example, when the wind farm, transmission line and power grid are connected in series in the wind power grid-connected system, the aggregate impedance model is:

[0063] Z(f)=Z C (U,I,f)+Z L (f)+Z G (f)

[0064] Among them, Z C (U,I,f),Z L (f) and Z G (f) Impedance models of wind turbine converter, transmission line and power grid respectively.

[0065] Thus, the embodiment of the present application can draw a frequency characteristic curve of the aggregate impedance Z(f). When it is found that the imaginary part of the impedance intersects the horizontal axis and the corresponding real part is a negative number, the system is unstable at this time, and the corresponding oscillation frequency is the frequency at the intersection of the imaginary part and the horizontal axis. Based on the above steps, the impedance model of each component can be calculated to further establish an aggregate impedance model, analyze the oscillation stability of the system, and obtain a rough value of the interharmonic frequency.

[0066] Furthermore, in order to solve the problem of low phasor measurement accuracy under the problem of signal discontinuity, firstly, the embodiment of the present application can use a and f cc The wide-spectrum phasor measurement is performed with the value, and the wide-spectrum phasor amplitude calculated at multiple moments before and after is continuously compared. When the wide-spectrum phasor amplitude measured at a certain moment suddenly increases, for example, from 0 to a certain threshold, it is considered that the signal is discontinuous. At this time, the wavelet coefficient a can be adjusted to improve the accuracy of the wide-spectrum phasor measurement.

[0067] Generally speaking, discontinuous signal components will make the spectrum leakage phenomenon more obvious, thereby reducing the accuracy of wide-spectrum phasor measurement. To this end, the current wide-spectrum phasor measurement accuracy can be improved by increasing the wavelet coefficient a and increasing the passband width, that is, reducing the passband ripple. The initial value of a can be set to 0.0004. When discontinuity is detected in the signal, a can be set to 0.003.

[0068] Furthermore, the embodiments of the present application can perform a wide-band oscillation stability analysis of the system based on the aggregate impedance model and estimate the wide-band oscillation frequency value. After the wide-band oscillation diverges for a period of time, the amplitude of the wide-band oscillation coupling component will increase. At this time, in addition to the main oscillation mode, there is also a coupled oscillation mode in the voltage and current signals. The spectra of different modes affect each other, thereby reducing the accuracy of wide-spectrum phasor measurement.

[0069] When the measured main oscillation amplitude exceeds a certain threshold of the fundamental wave, for example, exceeds 5% of the fundamental wave, the value of the wavelet coefficient a can be reduced, thereby improving the stopband attenuation capability of the wavelet filter and increasing the accuracy of wide-spectrum phasor measurement. According to the mechanism analysis of broadband oscillation, the frequency difference between different modes is 100Hz. When the amplitude of the main oscillation mode exceeds a certain threshold, the a value can be set from the original 0.003 to 0.0008. At this time, the spectrum interference generated by the broadband oscillation mode 100Hz away from the main oscillation mode can be effectively suppressed.

[0070] In summary, the embodiment of the present application determines the rough value of the interharmonic frequency through online stability analysis based on the impedance model. It only needs to calculate the fundamental voltage and current through FFT with a time window length of 1 fundamental cycle, and then substitute them into the impedance model to achieve it, which reduces the amount of calculation and has low latency. At the same time, by adaptively increasing the wavelet filter coefficient, the stopband attenuation capability is effectively improved, the mutual interference of the spectrum is suppressed, and the measurement accuracy of the wide-spectrum phasor is improved.

[0071] In step S103, the pulse per second PPS signal of the preset positioning system is used to time the broad-spectrum phasor measurement result, and the timed result is uploaded to the main station to obtain the final result.

[0072] In the actual implementation process, Figure 2 As shown, the embodiment of the present application first performs anti-aliasing filtering on the three-phase analog voltage and current signals, then performs analog-to-digital conversion on the analog signals after filtering, and finally performs wide-spectrum phasor measurement based on an adaptive wavelet filter. After obtaining the wide-spectrum phasor measurement results, the PPS signal emitted by the GPS or Beidou in the following steps is used to synchronize the measurement results, and the results after synchronization are uploaded to the main station to obtain the final results, thereby increasing the wavelet filter coefficient and improving the stopband attenuation capability, effectively suppressing the mutual interference of the spectrum, and improving the accuracy of the wide-spectrum phasor measurement.

[0073] It should be noted that the preset positioning system is set by those skilled in the art according to actual conditions and is not specifically limited here.

[0074] In one embodiment of the present application, uploading the result after timing synchronization to the main station includes: uploading the result after timing synchronization to the main station every preset time period.

[0075] In some embodiments, the embodiments of the present application can upload the timing results to the master station at regular intervals, for example, uploading the timing results to the master station every 5 seconds, thereby effectively improving the real-time performance of the power grid operation analysis.

[0076] It should be noted that the preset duration is set by those skilled in the art according to actual conditions and is not specifically limited here.

[0077] For example, Figure 3 As shown, it is a schematic diagram of the synchronous waveform acquisition principle of a specific embodiment of the present application. The embodiment of the present application first performs anti-aliasing filtering on the three-phase analog voltage and current signals, and then performs analog-to-digital conversion on the analog signals after filtering. The PPS signal sent by GPS or Beidou can be used to synchronize the sampling. In the case of limited communication channel capacity, the sampling signal can be downsampled, that is, one point is taken for each of several sampling points as the signal to be uploaded. The downsampling ratio can be set to 1, 1 / 2, 1 / 4 or 1 / 8. When it is set to 1, it means that no downsampling is performed. Finally, the collected waveform can be uploaded.

[0078] Specifically, waveform upload includes three modes: a. fixed interval upload, b. event triggered upload and c. call upload. The principles of these three upload modes will be introduced respectively below.

[0079] a. Regular interval upload: upload a fundamental frequency waveform at regular intervals.

[0080] b. Event-triggered upload: After a transient event occurs, the waveform of the 10 cycles before and after the event is uploaded. That is, after a sudden change in waveform energy is detected, the upload of the waveform of the 10 cycles before and after the event is initiated.

[0081] Among them, the above-mentioned transient event triggers the waveform acquisition mechanism, and its principle is: the waveform energy is calculated every 1 cycle. If the absolute value of the difference between the current cycle energy and the previous cycle energy (of either voltage or current phase) exceeds 0.09% of the previous cycle energy, it is considered that a transient event has occurred. At this time, the voltage and current waveforms start to be uploaded to the main station. The uploaded waveforms are the current waveform and 10 cycles of this waveform, a total of 21 cycles.

[0082] The waveform energy calculation method is:

[0083]

[0084] Where L is the length of the 1-cycle time window.

[0085] If the sampling rate is 12.8kHz, then L is 256, and the energy of the next cycle is:

[0086]

[0087] Next, calculate the relative deviation:

[0088]

[0089] If r>0.09% (ie, the equivalent amplitude exceeds 3%), it is considered that a transient mutation event exists and the waveform upload mechanism is triggered.

[0090] c. Call for upload: The waveform is uploaded continuously within the set time period. You can set the upload time period first and start uploading from the starting time. The upload time period is a few seconds / minutes / hours / days.

[0091] like Figure 4 As shown, the working principle of the embodiment of the present application is described in detail below with a specific embodiment.

[0092] Step S401: Sample the waveform values ​​of each phase of voltage and current respectively, and obtain N sampling points of data.

[0093] Step S402: Calculate fundamental voltage and current phasors based on FFT of one fundamental frequency cycle.

[0094] Step S403: Substitute the wind turbine impedance model to obtain a real-time impedance model, and obtain an aggregate impedance model according to the system topology.

[0095] Step S404: Perform an online analysis of the broadband oscillation stability of the system based on the aggregate impedance model, and roughly estimate the broadband oscillation frequency value.

[0096] Step S405: Substitute the rough oscillation frequency value into the wavelet filter formula, set the initial value of the wavelet coefficient a, calculate the broad-spectrum phasor value, and calculate the broad-spectrum frequency.

[0097] Step S406: Based on the calculated broad-spectrum phasor amplitude, if it is determined that the signal has undergone a sudden change, the wavelet coefficient a is increased.

[0098] Step S407: based on the calculated broad-spectrum phasor amplitude, if it is determined that the main oscillation mode exceeds a certain threshold, the wavelet coefficient a is reduced.

[0099] Step S408: output the broad-spectrum phasor and broad-spectrum frequency results, thereby effectively suppressing the mutual interference of the spectrum by increasing the wavelet filter coefficient and improving the accuracy of the broad-spectrum phasor measurement.

[0100] According to the synchronous waveform and wide-spectrum phasor measurement method proposed in the embodiment of the present application, three-phase analog voltage and current signals can be collected, and the three-phase analog voltage and current signals can be subjected to anti-aliasing filtering to obtain analog signals after filtering, thereby performing analog-to-digital conversion, and performing wide-spectrum phasor measurement based on an adaptive wavelet filter to obtain wide-spectrum phasor measurement results, using the pulse number per second PPS signal of the positioning system to time the wide-spectrum phasor measurement results, and uploading the timed results to the main station to obtain the final results, thereby effectively improving the stopband attenuation capability, suppressing mutual interference of the spectrum, and improving the measurement accuracy of the wide-spectrum phasor. Thus, the problems in the related art that there may be multiple modes in the broadband oscillation, resulting in the mutual influence of the spectrum between the multiple modes, reducing the accuracy of the wide-spectrum phasor measurement, and failing to meet the measurement requirements of the wide-spectrum phasor are solved.

[0101] Next, the synchronous waveform and wide-spectrum phasor measurement device proposed according to the embodiment of the present application is described with reference to the accompanying drawings.

[0102] Figure 5 It is a block diagram of a synchronous waveform and wide-spectrum phasor measurement device according to an embodiment of the present application.

[0103] like Figure 5 As shown, the synchronous waveform and wide-spectrum phasor measurement device 10 includes: a processing module 100 , a measurement module 200 and a control module 300 .

[0104] Specifically, the processing module 100 is used to collect three-phase analog voltage and current signals, and perform anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering.

[0105] The measurement module 200 is used to perform analog-to-digital conversion on the analog signal after filtering, and perform wide-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain a wide-spectrum phasor measurement result.

[0106] The control module 300 is used to use the pulse per second PPS signal of the preset positioning system to time the broad-spectrum phasor measurement results, and upload the timed results to the main station to obtain the final results.

[0107] Optionally, in one embodiment of the present application, the control module 300 is further configured to transmit the result after timing synchronization to the master station at a preset time interval.

[0108] Optionally, in one embodiment of the present application, the measurement module 200 is further used to calculate the broad spectrum phasor based on a wavelet filter, wherein the wavelet filter is:

[0109]

[0110] Among them, a is the wavelet coefficient that can be adjusted adaptively, f cc is the filter center frequency, f s Signal sampling frequency, n is the sampling point number.

[0111] Optionally, in one embodiment of the present application, the calculation formula of the broad spectrum phasor is:

[0112]

[0113] Among them, p ih (n) is the broad spectrum phasor value, and s(n) is the grid current signal containing fundamental and interharmonic / harmonic components.

[0114] Optionally, in one embodiment of the present application, a broad-spectrum phasor is calculated based on a wavelet filter, including generating sampling data using the voltage and current waveform sampling values ​​of each phase, calculating the fundamental voltage and current vector based on a fast Fourier transform (FFT) of one fundamental frequency, and substituting them into the wind turbine impedance model to obtain a real-time impedance model, and obtaining an aggregate impedance model based on the system topology, performing a broadband oscillation stability analysis of the system based on the aggregate impedance model, estimating the broadband oscillation frequency value, calculating the initial broad-spectrum phasor value and the initial broad-spectrum frequency based on the broadband oscillation frequency value, and adjusting the wavelet coefficient based on the initial broad-spectrum phasor amplitude until the final broad-spectrum phasor and the final broad-spectrum frequency are obtained.

[0115] It should be noted that the aforementioned explanation of the embodiment of the synchronous waveform and wide-spectrum phasor measurement method is also applicable to the synchronous waveform and wide-spectrum phasor measurement device of this embodiment, and will not be repeated here.

[0116] According to the synchronous waveform and wide-spectrum phasor measurement device proposed in the embodiment of the present application, three-phase analog voltage and current signals can be collected, and anti-aliasing filtering can be performed on the three-phase analog voltage and current signals to obtain analog signals after filtering, thereby performing analog-to-digital conversion, and performing wide-spectrum phasor measurement based on an adaptive wavelet filter to obtain wide-spectrum phasor measurement results, using the pulse number per second PPS signal of the positioning system to time the wide-spectrum phasor measurement results, and uploading the timed results to the main station to obtain the final results, thereby effectively improving the stopband attenuation capability, suppressing mutual interference of the spectrum, and improving the measurement accuracy of the wide-spectrum phasor. Thus, the problem in the related art that there may be multiple modes in the broadband oscillation, resulting in the mutual influence of the spectrum between the multiple modes, reducing the accuracy of the wide-spectrum phasor measurement, and failing to meet the measurement requirements of the wide-spectrum phasor is solved.

[0117] Figure 6A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0118] A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

[0119] When the processor 602 executes the program, the synchronous waveform and wide-spectrum phasor measurement method provided in the above embodiment is implemented.

[0120] Furthermore, the electronic device further comprises:

[0121] The communication interface 603 is used for communication between the memory 601 and the processor 602 .

[0122] The memory 601 is used to store computer programs that can be executed on the processor 602 .

[0123] The memory 601 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0124] If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0125] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

[0126] The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0127] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned synchronous waveform and wide-spectrum phasor measurement method.

[0128] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0129] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0130] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0131] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0132] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0133] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0134] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0135] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A synchronous waveform and broad spectrum phasor measurement method, characterized in that: The following steps are involved: Collecting three-phase analog voltage and current signals, and performing anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering; Performing analog-to-digital conversion on the filtered analog signal, and performing broad-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain a broad-spectrum phasor measurement result, wherein the broad-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain a broad-spectrum phasor measurement result includes: calculating the broad-spectrum phasor based on a wavelet filter, wherein the wavelet filter is: Among them, a is the wavelet coefficient that can be adjusted adaptively, f cc is the filter center frequency, f s Signal sampling frequency, n is the sampling point number; The calculation formula of the broad spectrum phase is: Among them, p ih (n) is a broad spectrum phasor value, s(n) is a grid current signal containing fundamental and interharmonic / harmonic components; and The broad-spectrum phasor measurement result is timed using a pulse per second (PPS) signal of a preset positioning system, and the timed result is uploaded to a master station to obtain a final result.

2. The method according to claim 1, characterized in that The step of uploading the timing result to the main station includes: The timing result is uploaded to the master station at preset time intervals.

3. The method according to claim 1, characterized in that The method of calculating the broad spectrum phasor based on the wavelet filter comprises: Generate sampling data using the waveform sampling values ​​of each phase of voltage and current; The fundamental voltage and current vectors are calculated based on the fast Fourier transform (FFT) of one fundamental frequency, and substituted into the wind turbine impedance model to obtain a real-time impedance model, and an aggregate impedance model is obtained according to the system topology; Based on the aggregate impedance model, a broadband oscillation stability analysis of the system is performed to estimate the broadband oscillation frequency value; An initial broad-spectrum phasor value and an initial broad-spectrum frequency are calculated according to the broadband oscillation frequency value, so as to adjust the wavelet coefficient based on the initial broad-spectrum phasor amplitude until a final broad-spectrum phasor and a final broad-spectrum frequency are obtained.

4. A synchronous waveform and broad spectrum phasor measurement device, characterized in that: The following steps are involved: A processing module, used for collecting three-phase analog voltage and current signals, and performing anti-aliasing filtering on the three-phase analog voltage and current signals to obtain analog signals after filtering; A measurement module is used to perform analog-to-digital conversion on the analog signal after the filtering process, and perform broad-spectrum phasor measurement based on a preset adaptive wavelet filter to obtain a broad-spectrum phasor measurement result, wherein the broad-spectrum phasor measurement based on the preset adaptive wavelet filter to obtain the broad-spectrum phasor measurement result includes: calculating the broad-spectrum phasor based on the wavelet filter, wherein the wavelet filter is: Among them, a is the wavelet coefficient that can be adjusted adaptively, f cc is the filter center frequency, f s Signal sampling frequency, n is the sampling point number; The calculation formula of the broad spectrum phase is: Among them, p ih (n) is a broad spectrum phasor value, s(n) is a grid current signal containing fundamental and interharmonic / harmonic components; and The control module is used to use the pulse per second PPS signal of the preset positioning system to time the broad-spectrum phasor measurement result, and upload the timed result to the main station to obtain the final result.

5. The device according to claim 4, characterized in that The control module is further used to upload the timing result to the main station at preset time intervals.

6. The device according to claim 4, characterized in that The method of calculating the broad-spectrum phasor based on the wavelet filter includes generating sampling data by using the waveform sampling values ​​of each phase of the voltage and current, calculating the fundamental voltage and current vector based on the fast Fourier transform (FFT) of one fundamental frequency, substituting the fundamental voltage and current vector into the impedance model of the wind turbine generator set to obtain a real-time impedance model, and obtaining an aggregate impedance model according to the system topology, performing a broadband oscillation stability analysis of the system based on the aggregate impedance model, estimating the broadband oscillation frequency value, calculating the initial broad-spectrum phasor value and the initial broad-spectrum frequency according to the broadband oscillation frequency value, and adjusting the wavelet coefficient based on the initial broad-spectrum phasor amplitude until a final broad-spectrum phasor and a final broad-spectrum frequency are obtained.

7. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the synchronous waveform and broad-spectrum phasor measurement method as described in any one of claims 1 to 3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the synchronous waveform and wide-spectrum phasor measurement method as described in any one of claims 1 to 3.

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