CN117517794A - Dielectric loss angle measurement method and device for electrical equipment - Google Patents
Dielectric loss angle measurement method and device for electrical equipment Download PDFInfo
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Abstract
The application relates to a dielectric loss angle measurement method and a dielectric loss angle measurement device for electrical equipment, wherein the dielectric loss angle measurement method for the electrical equipment comprises the following steps: collecting signals of electrical equipment, and windowing the signals to obtain a double-window output sequence; segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point; performing signal processing on the target input points to obtain output results of the target input points in the plurality of data segments, and transforming the output results to obtain target output results of the frequency domain; and measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method. Through this application, solved the lower problem of measurement accuracy of electrical equipment's dielectric loss angle.
Description
Technical Field
The present disclosure relates to the field of signal processing, and in particular, to a dielectric loss angle measurement method and apparatus for an electrical device.
Background
In an electrical power system, an insulating layer of an electrical device is used to isolate a high voltage line, preventing current leakage and occurrence of electric shock accidents. In electronic devices, insulators are used to protect circuits and components from electrical interference and damage. In home and office environments, various electrical equipment housings and internal circuits are often made of insulating materials to ensure safe use. It is therefore necessary to measure the dielectric loss angle of the signal in the electrical equipment and thus detect whether there is a defect in the insulation of the electrical equipment.
In the prior art, a digital western-style bridge is a special instrument for measuring insulation of electrical equipment; directly comparing the signal phases in a time domain by adopting a voltage zero crossing method, and further measuring the dielectric loss angle of the digital western forest bridge; however, the requirements of the mode on the sampling rate, the resolution of the acquisition card, the environmental noise and the filtering are very high, so that the measurement stability is changed due to the fact that the mode is particularly easy to be interfered in the experimental process, and the measurement accuracy of the dielectric loss angle is low. Meanwhile, a signal is generally subjected to frequency domain processing by using fast fourier transform (Fast Fourier Transform, FFT), but when the signal is processed by FFT, N-segment signal data is extracted to perform FFT operation, and frequency spectrum leakage is easily generated due to limited FFT variation in the extraction process, so that the measurement accuracy of the dielectric loss angle is low.
Aiming at the problem of lower measurement accuracy of dielectric loss angle of electrical equipment in the related art, no effective solution is proposed at present.
Disclosure of Invention
The embodiment provides a dielectric loss angle measuring method and device for electrical equipment, which are used for solving the problem that the dielectric loss angle of the electrical equipment is low in measuring precision in the related technology.
In a first aspect, in this embodiment, there is provided a dielectric loss angle measurement method of an electrical apparatus, including:
collecting signals of electrical equipment, and windowing the signals to obtain a double-window output sequence;
segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point;
performing signal processing on the target input points to obtain output results of the target input points in the data segments, and transforming the output results to obtain target output results of a frequency domain;
and measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method.
In some embodiments, the acquiring the signal of the electrical device and windowing the signal to obtain a double window output sequence includes:
weighting the signals according to a preset windowing sequence to obtain an initial sequence;
performing cycle prolongation treatment on the initial sequence at a preset position to obtain an intermediate sequence;
weighting the intermediate sequence in the vertical direction according to a preset windowing sequence to obtain a double-weighted intermediate sequence;
summing the double weighted intermediate sequences in the vertical direction to form a periodic sequence;
and processing the periodic sequence according to a preset function to obtain a double-window output sequence.
In some embodiments, the segmenting the dual window output sequence results in a plurality of data segments; wherein the plurality of data segments each include a target input point, comprising:
the dual window output sequence is evenly divided into a plurality of data segments so that the target input point traverses all moments of the dual window output sequence.
In some embodiments, the signal processing on the target input point to obtain output results of the target input points in the plurality of data segments, and transforming the output results to obtain a target output result in a frequency domain, including:
according to different moments of the target input point in the data segments, performing signal processing on the target input point to obtain a plurality of data segment output results corresponding to the target input point;
calculating arithmetic average of the sum of the output results of the data segments to obtain a target output result of a time domain;
and carrying out Fourier transform on the target output result of the time domain to obtain the target output result of the frequency domain.
In some embodiments, the signal corresponding to the target output result of the frequency domain presents square regular attenuation so as to inhibit spectrum leakage.
In some embodiments, the regular attenuation of the square of the signal corresponding to the target output result of the frequency domain is: the ratio of the side lobe to the main spectral line in the frequency spectrum decays according to the rule of square, and the frequency spectrum is the frequency spectrum of the target output result of the frequency domain of the signal.
In some embodiments, the processing the periodic sequence according to a preset function to obtain a double window output sequence includes:
cutting off the periodic sequence by using a preset rectangular window function to obtain a cut-off periodic sequence;
and determining the cut periodic sequence as the double-window output sequence.
In a second aspect, in this embodiment, there is provided a dielectric loss angle measurement device for an electrical apparatus, the device including: the device comprises an acquisition module, a processing module and a measurement module;
the acquisition module is used for acquiring signals of the electrical equipment;
the processing module is used for windowing the signals to obtain a double-window output sequence; the method is also used for segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point; the method is also used for carrying out signal processing on the target input points to obtain output results of the target input points in the data segments, and transforming the output results to obtain target output results of a frequency domain;
the measuring module is used for measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method.
In a third aspect, in this embodiment, there is provided an electronic apparatus including a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor implements the dielectric loss angle measurement method of the electrical device according to the first aspect.
In a fourth aspect, in the present embodiment, there is provided a storage medium having stored thereon a computer program which, when executed by a processor, implements the dielectric loss angle measurement method of the electrical apparatus described in the first aspect.
Compared with the related art, the dielectric loss angle measuring method of the electrical equipment provided by the embodiment acquires signals of the electrical equipment and performs windowing processing on the signals to obtain a double-window output sequence; segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point; performing signal processing on the target input points to obtain output results of the target input points in the data segments, and transforming the output results to obtain target output results of a frequency domain; according to the target output result of the frequency domain and a preset measuring method, the dielectric loss angle of the electrical equipment is measured, spectrum leakage is restrained, and further the measuring precision of the dielectric loss angle of the electrical equipment is improved.
The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the other features, objects, and advantages of the application.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:
fig. 1 is a block diagram of the hardware configuration of a terminal of a dielectric loss angle measurement method of an electrical device according to an embodiment of the present application.
Fig. 2 is a flowchart of a dielectric loss angle measurement method of an electrical device according to an embodiment of the present application.
Fig. 3 is a flowchart of a signal processing method of the electrical device of the present embodiment.
Fig. 4 is a flowchart of windowing processing using full phase fourier transform in this particular embodiment.
Fig. 5 is a schematic diagram of spectral analysis of the window of the present embodiment.
Fig. 6a is a graph of a fast fourier transform of an input signal in this embodiment.
Fig. 6b is a diagram of a full phase fft of an input signal in this embodiment.
Fig. 7 is a block diagram of the structure of the dielectric loss angle measurement device of the electric apparatus according to the embodiment of the present application.
Detailed Description
For a clearer understanding of the objects, technical solutions and advantages of the present application, the present application is described and illustrated below with reference to the accompanying drawings and examples.
Unless defined otherwise, technical or scientific terms used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms "a," "an," "the," "these," and the like in this application are not intended to be limiting in number, but rather are singular or plural. The terms "comprising," "including," "having," and any variations thereof, as used in the present application, are intended to cover a non-exclusive inclusion; for example, a process, method, and system, article, or apparatus that comprises a list of steps or modules (units) is not limited to the list of steps or modules (units), but may include other steps or modules (units) not listed or inherent to such process, method, article, or apparatus. The terms "connected," "coupled," and the like in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Reference to "a plurality" in this application means two or more. "and/or" describes an association relationship of an association object, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone. Typically, the character "/" indicates that the associated object is an "or" relationship. The terms "first," "second," "third," and the like, as referred to in this application, merely distinguish similar objects and do not represent a particular ordering of objects.
The method embodiments provided in the present embodiment may be executed in a terminal, a computer, or similar computing device. For example, the terminal is operated, and fig. 1 is a block diagram of a hardware structure of the terminal of the dielectric loss angle measurement method of the electrical device according to the embodiment of the present application. As shown in fig. 1, the terminal may include one or more (only one is shown in fig. 1) processors 102 and a memory 104 for storing data, wherein the processors 102 may include, but are not limited to, a microprocessor MCU, a programmable logic device FPGA, or the like. The terminal may also include a transmission device 106 for communication functions and an input-output device 108. It will be appreciated by those skilled in the art that the structure shown in fig. 1 is merely illustrative and is not intended to limit the structure of the terminal. For example, the terminal may also include more or fewer components than shown in fig. 1, or have a different configuration than shown in fig. 1.
The memory 104 may be used to store a computer program, for example, a software program of application software and a module, such as a computer program corresponding to a dielectric loss angle measurement method of an electrical device in the present embodiment, and the processor 102 executes the computer program stored in the memory 104 to perform various functional applications and data processing, that is, to implement the above-described method. Memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, which may be connected to the terminal via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The transmission device 106 is used to receive or transmit data via a network. The network includes a wireless network provided by a communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, simply referred to as NIC) that can connect to other network devices through a base station to communicate with the internet. In one example, the transmission device 106 may be a Radio Frequency (RF) module, which is configured to communicate with the internet wirelessly.
In this embodiment, a method for measuring a dielectric loss angle of an electrical device is provided, and fig. 2 is a flowchart of the method for measuring a dielectric loss angle of an electrical device according to an embodiment of the present application, as shown in fig. 2, where the flowchart includes the following steps:
step S210, signals of the electrical equipment are collected, and windowing processing is carried out on the signals, so that a double-window output sequence is obtained.
Specifically, when the dielectric loss angle of the electrical equipment is measured, firstly, a processor collects signals of the electrical equipment, and then windowing is carried out on the signals to obtain a double-window output sequence; by windowing the signal of the electrical device, it is advantageous to suppress spectral leakage of the signal.
Step S220, segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target entry point.
Specifically, after obtaining the double-window output sequence, the processor segments the double-window output sequence, so as to obtain a plurality of data segments of the double-window output sequence, wherein the plurality of data segments comprise target input points.
Step S230, signal processing is performed on the target input points to obtain output results of the target input points in the plurality of data segments, and the output results are transformed to obtain target output results of the frequency domain.
Specifically, the processor respectively performs signal processing on a plurality of target input points, so as to obtain output results corresponding to the target input points in a plurality of data segments; then, the output result is transformed by a preset method, and the target output result of the frequency domain is obtained.
Step S240, measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method.
Specifically, the processor measures the dielectric loss angle of the electrical equipment according to the obtained target output result of the frequency domain and a preset measurement method.
Through the steps, the processor acquires signals of the electrical equipment and performs windowing processing on the signals of the electrical equipment to obtain a double-window output sequence; segmenting the double-window output sequence to obtain a plurality of data segments, performing signal processing on target input points in the data segments to obtain output results corresponding to the plurality of target input points, and finally transforming the output results to obtain target output results of a frequency domain; and then according to the target output result of the frequency domain and a preset measuring method, the dielectric loss angle of the electrical equipment is measured, so that the frequency spectrum leakage is effectively restrained, the accuracy of the signal in the frequency domain is further improved, and the accuracy of the dielectric loss angle measurement of the electrical equipment is further improved.
In some of these embodiments, step S210 includes steps S211 to S215.
Step S211, weighting the signals according to a preset windowing sequence to obtain an initial sequence.
Step S212, performing cycle extension processing on the initial sequence at a preset position to obtain an intermediate sequence.
And step S213, carrying out weighting treatment on the intermediate sequence in the vertical direction according to a preset windowing sequence to obtain a double-weighted intermediate sequence.
Step S214, summing the double weighted intermediate sequences in the vertical direction to form a periodic sequence.
Step S215, the periodic sequence is processed according to a preset function, and a double-window output sequence is obtained.
Specifically, the processor weights the signals by using a preset windowing sequence to obtain a weighted initial sequence; performing cycle prolongation processing on the windowed initial sequence data at a preset position, namely a home position; obtaining intermediate sequence data; then, according to a preset windowing sequence, weighting the intermediate sequence in the vertical direction of a preset position to obtain a double-weighted intermediate sequence; summing the double weighted intermediate sequences in the vertical direction of the preset position to form a periodic sequence; and processing the periodic sequence according to a preset function to obtain a double-window output sequence.
Through the steps, the windowing processing is carried out on the collected signals of the electrical equipment, so that the signals become smoother in the time domain, the frequency spectrum leakage degree is reduced, and the frequency domain resolution of the signals is improved. In addition, the windowing can also inhibit side lobes of the signal, thereby inhibiting spectral leakage.
In some of these embodiments, step S220 includes step S221.
The step S221 is to divide the double window output sequence into a plurality of data segments so that the target input point traverses all the time points of the double window output sequence.
Specifically, the processor performs windowing processing on the acquired signals of the electrical equipment to obtain a double-window output sequence, wherein the double-window output sequence is discrete; the dual window output sequence is thus evenly divided into a plurality of data segments, each of which includes a target input point, so that the target input point traverses all moments of the dual window output sequence, so that the set of target input points in all data segments is contiguous. Through the steps, the discrete double-window output sequence is output as a continuous target input point, so that continuous output is facilitated, a cut-off error of subsequent Fourier transformation of the signal is eliminated, and spectrum leakage is further suppressed.
In some of these embodiments, step S230 includes steps S231 to S233.
In step S231, signal processing is performed on the target input point according to different moments of the target input point in the plurality of data segments, so as to obtain a plurality of data segment output results corresponding to the target input point.
Specifically, the processor performs signal processing on target input points in a plurality of data segments at different moments to obtain output results corresponding to the target input points in the plurality of data segments.
Step S232, calculating arithmetic average of the sum of the output results of the data segments to obtain a target output result of the time domain.
Specifically, the processor performs arithmetic average on the sum of output results corresponding to the target input points in the plurality of data segments, so as to obtain a target output result in the time domain.
Step S233, performing Fourier transform on the target output result of the time domain to obtain the target output result of the frequency domain.
Specifically, the processor performs fourier transform on the target output result of the time domain, that is, transforms from the time domain to the frequency domain, and further obtains the target output result of the frequency domain.
Through the steps, the processor performs signal processing on target input points in a plurality of data segments at different moments to obtain output results corresponding to the target input points in the plurality of data segments, and performs arithmetic average on the sum of the output results to obtain a target output result in a time domain. And then carrying out Fourier transform on the target output result to obtain a frequency domain target output result, thereby being beneficial to improving the subsequent measurement precision of the dielectric loss value of the electrical equipment.
In some of these embodiments, the signal corresponding to the target output result of the frequency domain exhibits a regular decay of square, so as to suppress spectrum leakage.
Specifically, the result obtained after fourier transformation of the target output result is attenuated in a square rule, so that spectrum leakage is suppressed.
In some embodiments, the regular decay of the square of the signal corresponding to the target output result in the frequency domain is: the ratio of the side lobe to the main spectral line in the frequency spectrum is attenuated according to the rule of square, and the frequency spectrum is the frequency spectrum of the target output result of the frequency domain of the signal.
Specifically, the regular attenuation of the square of the signal corresponding to the target output result of the frequency domain is specifically: in a result obtained after the Fourier transform is performed on the target output result, the attenuation of the ratio of the side lobe of the frequency spectrum to the main spectral line shows a square rule, and the fast Fourier transform can be understood as compared with the fast Fourier transform of the signal of the electrical equipment, and the frequency spectrum leakage can be well restrained by the scheme.
In some of these embodiments, step S215 includes steps S2151 through S2152.
Step S2151, the periodic sequence is truncated by using a preset rectangular window function, and the truncated periodic sequence is obtained.
Specifically, the processor truncates the periodic sequence by using a preset rectangular window function, so as to obtain a truncated periodic sequence.
In step S2152, the truncated periodic sequence is determined to be a double window output sequence.
Specifically, the processor determines the truncated periodic sequence as a double window output sequence.
Through the steps, the processor cuts the periodic sequence by using a preset rectangular window function, and determines the cut periodic sequence to be a double-window output sequence, so that frequency components are effectively limited, frequency spectrum leakage is reduced, and the periodicity of signals is maintained.
The present embodiment is described and illustrated below by way of specific examples.
Fig. 3 is a flowchart of a signal processing method of the electrical device according to the present embodiment, and as shown in fig. 3, the signal processing method of the electrical device includes the steps of:
step S310, collecting signals of the electrical device.
Specifically, a capacitance signal and a current signal of the electrical equipment are collected, and then the dielectric loss of the electrical equipment is measured by using a digital xilin bridge. Wherein the xilin bridge calculates the dielectric loss by measuring the phase difference between the capacitance and the inductance. Therefore, it is necessary to acquire a capacitance signal of the electrical device. Second, dielectric losses are related to current flow, and thus there is also a need to collect operating current signals for electrical equipment. Because digital xilin bridges typically employ digital measurement techniques, analog capacitance and current signals are converted to digital signals for processing. Thus, the acquired capacitance and current signals are discrete digital values, rather than continuous analog signals. The discrete digital signals are processed and analyzed to calculate dielectric loss values for the electrical device. From these measurements, dielectric loss values of the electrical devices can be obtained, thereby evaluating the insulation properties thereof.
Step S320, windowing is performed on the signal.
Specifically, the signals of the electrical devices are first weighted using a window sequence; performing periodic continuation on the windowed data on the basis of the in-situ position; the sequence which is subjected to periodic continuation on the basis of the original position is weighted in the vertical direction by the window sequence; summing the sequences of which the double weighted periods are expanded in the vertical direction to form a new period sequence; and finally, cutting off the new periodic sequence by using a rectangular window to generate a double-window full-phase input sequence. The signals of the electrical devices are windowed to thereby suppress spectral leakage.
In step S330, a continuous output signal is obtained by using the maximum overlap method of the full-phase fourier transform.
Specifically, a maximum overlapping method of full-phase Fourier transform is adopted, the signal data input after windowing is divided into N sections, and N is a positive integer greater than 1; any input point x (N) may appear in any data segment, and illustratively, N segments of data may be represented as:
wherein x (n) appears in each piece of data, which corresponds to all times when all data are traversed, and the corresponding output result of x (n) in the first piece of data is y (0) (N) the corresponding output result in the nth segment data is y (N-1) (N) performing arithmetic mean on output results of all x (N) in the N sections of data, and taking the obtained final result as output; the input in the N-order full-phase algorithm adopts (N-1)/N overlap, which is equivalent to continuous data to generate continuous output, and truncation errors in the fast Fourier transform (Fast Fourier Transform, FFT) are eliminated, namely, spectrum leakage is restrained. The output result is expressed as:
where x (ap) represents the input result of the full phase fourier transform, N represents the number of data segments, and T represents the transpose.
Step S340, fourier transforming the output result.
Specifically, FFT operation is performed on the output result x (ap) obtained in step S320, and the obtained result Xap (k) is:
ω 0 ＝2βπ/N
i，k＝0，1，2…N-1
wherein Xi (k) is the output result x (ap), N represents the sampling interval, N represents the number of data segments, j is the imaginary number, ω 0 Which represents the angular frequency of the light emitted by the light source,representing the initial phase, and β represents the ratio of the number of sampling points to the sampling interval. From the above equation, the result of the full-phase FFT has square property, which means that the ratio attenuation of the side lobe relative to the main spectral line also attenuates in square form, and the full-phase fourier transform has better ability to suppress spectrum leakage than the case of directly performing FFT operation on the signal. And the phase value of the signal can be obtained, and the phase is not influenced by other factors.
Referring to fig. 4, fig. 4 is a flowchart of windowing processing using full phase fourier transform in the present embodiment. Through full-phase Fourier transform, spectrum leakage can be effectively restrained, signal processing performance is improved, and accuracy of signal phase calculation in a frequency domain is improved. As shown in fig. 4, the signal of the electrical device is Z-transformed to obtain x (n+1), x (N) and x (N-1), and then the signal is subjected to full-phase processing, that is, a data vector with a length (2N-1) centered on x (0) is weighted by a convolution window Wc (N), and then shift and sum are performed, where Wc (N) is:
w c (n)＝f(n)*b(-n)
wherein f (N) represents a front window, b (-N) represents a rear window obtained by turning the front window, and N E [ -N+1, N-1]. I.e. the signal with the length of (2N-1) is weighted and truncated by a window function Wc (N) with the length of (2N-1); then, the data points with the interval of N are added two by two to obtain data with the length of N, namely 6x (N), [4x (N-1) +x (n+1) ] and [4x (n+1) +x (N-1) ]; and finally, performing fast Fourier transform analysis on the processed signal with the number of N, taking an absolute value of an analysis result, and converting the complex form Fourier transform result into an amplitude form so as to facilitate analysis and observation. In fourier transforms, the output results are typically represented in complex form, comprising a real part and an imaginary part. And an Absolute value function (ABS) takes the complex number as the Absolute value, i.e. only the amplitude information is retained, so that the complex form fourier transform result is converted into a single amplitude value, which is convenient for subsequent analysis and processing.
In one embodiment, a Hanning window (Hanning window) and a four-term third-order Natuol window (Nuttall window) are used for convolutionAccording to the definition of the mixed convolution window, a first-order mixed convolution frequency domain expression W formed by a Hanning window and a Nuttall window 1-NH (k) Second-order mixed convolution frequency domain expression W 2-NH (k) The method comprises the following steps:
wherein W is N (k) Representing a Hanning window, W H (k) Indicating a nutall window, N is a positive integer, and j is an imaginary number.
Referring to fig. 5, fig. 5 is a schematic diagram of spectrum analysis of the window of the present embodiment. According to a first-order mixed convolution frequency domain expression and a second-order mixed convolution frequency domain expression formed by a Hanning window and a nuttal window, performing spectrum analysis on the first-order mixed convolution window and the second-order mixed convolution window; in fig. 5, the horizontal axis represents normalized frequency, and the vertical axis represents amplitude; as can be seen from fig. 5, the second-order hybrid window has lower side lobe peak values and higher attenuation speed than the first-order hybrid window. The performance of the second-order mixed convolution window is obviously better than that of the first-order mixed convolution window; therefore, there is less spectral leakage when the signal of the electrical device is truncated using a second order hybrid convolution window.
In one embodiment, the following input signals are present:
the traditional FFT is carried out on the input signal, and the obtained output result is:
the input signal is subjected to full-phase FFT, and the obtained output result is:
wherein n representsSample interval j is imaginary number, ω 0 Which represents the angular frequency of the light emitted by the light source,the initial phase is represented, N represents the number of signal samples, and beta represents the ratio of the number of samples to the sampling interval.
Comparing the output results of the different FFTs can be known: in amplitude, the fourier transformed amplitude spectrum of the full phase processed signal is directly fourier transformed to the square of the amplitude spectrum. This means that the main lobe of the full-phase FFT is more prominent, the attenuation of the side lobe is faster, the frequency spectrum leakage is smaller, the measurement precision of the dielectric loss of the electrical equipment is improved, and the accuracy of judging the insulation defect of the electrical equipment is improved. In phase, the phase of a conventional FFT is related to the frequency offset, while the phase of the full-phase FFT spectrum is always equal to the phase value of the center sample x (0)I.e. the phase of the full phase FFT has a "phase invariance".
The frequency of the input signal x (n) is 30Hz, the initial phase is 60 °, and the input signal is subjected to FFT and full-phase FFT analysis, respectively, and the phase spectrum is shown in fig. 6. Fig. 6a is a graph of a fast fourier transform of an input signal in this embodiment. Fig. 6b is a diagram of a full phase fft of an input signal in this embodiment. Referring to fig. 6a and 6b, the horizontal axis represents frequency and the vertical axis represents phase. When the full-phase FFT is in the same frequency, the phase is always equal to the phase of the center sample point x (0), the frequency domain dispersion does not have a fence effect, and a spectral line is directly selected near the frequency on the phase spectrum, namely the initial phase of the frequency component. In addition, compared with the FFT algorithm, the full-phase FFT does not need to carry out interpolation correction, so that the calculation amount is reduced, and meanwhile, the more accurate phase is obtained.
It should be noted that the steps illustrated in the above-described flow or in the flow diagrams of the figures may be performed in a computer system, such as a set of computer-executable instructions.
The embodiment also provides a dielectric loss angle measurement device of an electrical device, which is used for implementing the above embodiment and the preferred implementation manner, and is not described in detail. The terms "module," "unit," "sub-unit," and the like as used below may refer to a combination of software and/or hardware that performs a predetermined function. While the means described in the following embodiments are preferably implemented in software, implementations in hardware, or a combination of software and hardware, are also possible and contemplated.
Fig. 7 is a block diagram of a dielectric loss angle measurement apparatus of an electrical device according to an embodiment of the present application, and as shown in fig. 7, the apparatus includes: an acquisition module 10, a processing module 20 and a measurement module 30.
The acquisition module 10 is used for acquiring signals of the electrical equipment.
A processing module 20, configured to perform windowing processing on the signal to obtain a dual-window output sequence; the method is also used for segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point; and the method is also used for carrying out signal processing on the target input points to obtain output results of the target input points in the plurality of data segments, and transforming the output results to obtain target output results of the frequency domain.
The measurement module 30 is configured to measure a dielectric loss angle of the electrical device according to the target output result of the frequency domain and a preset measurement method.
The above-described respective modules may be functional modules or program modules, and may be implemented by software or hardware. For modules implemented in hardware, the various modules described above may be located in the same processor; or the above modules may be located in different processors in any combination.
There is also provided in this embodiment an electronic device comprising a memory having stored therein a computer program and a processor arranged to run the computer program to perform the steps of any of the method embodiments described above.
Optionally, the electronic apparatus may further include a transmission device and an input/output device, where the transmission device is connected to the processor, and the input/output device is connected to the processor.
Alternatively, in the present embodiment, the above-described processor may be configured to execute the following steps by a computer program:
s1, acquiring signals of electrical equipment, and windowing the signals to obtain a double-window output sequence.
S2, segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target entry point.
S3, performing signal processing on the target input points to obtain output results of the target input points in the data segments, and transforming the output results to obtain target output results of the frequency domain.
S4, measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method.
It should be noted that, specific examples in this embodiment may refer to examples described in the foregoing embodiments and alternative implementations, and are not described in detail in this embodiment.
In addition, in combination with the dielectric loss angle measurement method of the electrical apparatus provided in the above embodiment, a storage medium may be provided in the present embodiment. The storage medium has a computer program stored thereon; the computer program, when executed by a processor, implements the dielectric loss angle measurement method of any one of the electrical devices of the above embodiments.
It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to be limiting. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present application, are within the scope of the present application in light of the embodiments provided herein.
It is evident that the drawings are only examples or embodiments of the present application, from which the present application can also be adapted to other similar situations by a person skilled in the art without the inventive effort. In addition, it should be appreciated that while the development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as an admission of insufficient detail.
The term "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive. It will be clear or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the patent. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.
Claims (10)
1. A method of measuring dielectric loss angle of an electrical device, the method comprising:
collecting signals of electrical equipment, and windowing the signals to obtain a double-window output sequence;
segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point;
performing signal processing on the target input points to obtain output results of the target input points in the data segments, and transforming the output results to obtain target output results of a frequency domain;
and measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method.
2. The method for measuring the dielectric loss angle of the electrical equipment according to claim 1, wherein the steps of collecting the signal of the electrical equipment and windowing the signal to obtain a double-window output sequence comprise:
weighting the signals according to a preset windowing sequence to obtain an initial sequence;
performing cycle prolongation treatment on the initial sequence at a preset position to obtain an intermediate sequence;
weighting the intermediate sequence in the vertical direction according to a preset windowing sequence to obtain a double-weighted intermediate sequence;
summing the double weighted intermediate sequences in the vertical direction to form a periodic sequence;
and processing the periodic sequence according to a preset function to obtain a double-window output sequence.
3. The method for measuring the dielectric loss angle of the electrical equipment according to claim 1, wherein the double window output sequence is segmented to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point, comprising:
the dual window output sequence is evenly divided into a plurality of data segments so that the target input point traverses all moments of the dual window output sequence.
4. The method for measuring a dielectric loss angle of an electrical device according to claim 1, wherein the performing signal processing on the target input point to obtain output results of target input points in the plurality of data segments, and transforming the output results to obtain target output results in a frequency domain, includes:
according to different moments of the target input point in the data segments, performing signal processing on the target input point to obtain a plurality of data segment output results corresponding to the target input point;
calculating arithmetic average of the sum of the output results of the data segments to obtain a target output result of a time domain;
and carrying out Fourier transform on the target output result of the time domain to obtain the target output result of the frequency domain.
5. The method for measuring the dielectric loss angle of the electrical equipment according to claim 1, wherein the signal corresponding to the target output result of the frequency domain exhibits regular attenuation of square to suppress spectrum leakage.
6. The method for measuring a dielectric loss angle of an electrical device according to claim 5, wherein the regular attenuation of the square of the signal corresponding to the target output result in the frequency domain is: the ratio of the side lobe to the main spectral line in the frequency spectrum decays according to the rule of square, and the frequency spectrum is the frequency spectrum of the target output result of the frequency domain of the signal.
7. The method for measuring the dielectric loss angle of the electrical equipment according to claim 2, wherein the processing the periodic sequence according to a preset function to obtain a double window output sequence comprises:
cutting off the periodic sequence by using a preset rectangular window function to obtain a cut-off periodic sequence;
and determining the cut periodic sequence as the double-window output sequence.
8. A dielectric loss angle measurement apparatus for an electrical device, the apparatus comprising: the device comprises an acquisition module, a processing module and a measurement module;
the acquisition module is used for acquiring signals of the electrical equipment;
the processing module is used for windowing the signals to obtain a double-window output sequence; the method is also used for segmenting the double-window output sequence to obtain a plurality of data segments; wherein the plurality of data segments each include a target input point; the method is also used for carrying out signal processing on the target input points to obtain output results of the target input points in the data segments, and transforming the output results to obtain target output results of a frequency domain;
the measuring module is used for measuring the dielectric loss angle of the electrical equipment according to the target output result of the frequency domain and a preset measuring method.
9. An electronic device comprising a memory and a processor, characterized in that the memory has stored therein a computer program, the processor being arranged to run the computer program to perform the dielectric loss angle measurement method of an electrical apparatus according to any of claims 1 to 7.
10. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the dielectric loss angle measurement method of an electrical device according to any one of claims 1 to 7.
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