CN110244151B - Synchronous phasor measurement method and system and related components - Google Patents
Synchronous phasor measurement method and system and related components Download PDFInfo
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Abstract
The application discloses a synchronous phasor measurement method, a system and related components, which comprise: acquiring a power signal, and adding an absolute time scale output by a 5G clock to the power signal; acquiring an amplitude-frequency response curve of the power signal; determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal; and calculating fundamental phasor parameters of the power signals through an algorithm corresponding to the state. This application adopts and to have short time delay, high reliability, the time of high accuracy, high bandwidth superior communication performance's such as 5G carry out data transmission and time of, can satisfy the requirement of joining in marriage synchronous phasor measuring device to transmission delay, has saved GPS's input and communication such as optic fibre and has invested to save synchronous phasor measuring device's cost, measurement accuracy is high, improves the distribution network wide area and observes and controls the application effect of protection senior application.
Description
Technical Field
The present application relates to the field of power distribution networks, and in particular, to a method and system for synchronous phasor measurement and related components.
Background
The synchronous phasor measurement device can be used in the fields of dynamic monitoring, system protection, system analysis and prediction and the like of a power system, and is important equipment for ensuring safe operation of a power grid. The synchronous phasor measurement device is easy to encounter the following problems in the popularization and application process of the power distribution network: firstly, the synchrophasor measurement device needs to be internally provided with a GPS module, or a GPS (Global Positioning System) device is installed on site, so that the cost is high, and meanwhile, a GPS antenna is difficult to be shielded in the field installation process, so that GPS signal is poor, and high-precision time setting cannot be realized; secondly, at present, a plurality of towers and power distribution rooms have harsh conditions, no optical fiber and network wired interface are provided, and the optical fiber laying investment cost is high, under the condition, a 4G module is arranged in the existing synchronous phasor measuring device, in the field practical application process, the signal stability of the 4G module is poor, a certain packet loss rate exists, the bandwidth requirement of the synchronous phasor quick uploading is difficult to meet, the transmission delay fluctuation is large, the delay is long, the requirement of a power distribution network on closed-loop real-time control is difficult to meet, and the application effect of the high-grade application function of a main station is influenced; thirdly, because the current power distribution network has more power electronic devices, the voltage and current signal distortion of the power distribution network is larger, and the current synchronous phasor measurement algorithm cannot well process the influences of harmonic waves, inter-harmonic waves, attenuated direct current components, amplitude modulation and phase angle modulation at the same time, so that the synchronous phasor measurement precision is poorer in the dynamic process of the power distribution network, and the application effect of wide-area measurement and control protection advanced application of the power distribution network is influenced.
Therefore, how to provide a solution to the above technical problem is a problem that needs to be solved by those skilled in the art.
Disclosure of Invention
The application aims at providing a synchronous phasor measurement method, a system and related components, meeting the requirement of a distribution network synchronous phasor measurement device on transmission delay, saving the input of a GPS (global positioning system) and the input of communication such as optical fibers, saving the cost of the synchronous phasor measurement device, having high measurement precision and improving the application effect of wide-area measurement and control protection advanced application of a distribution network.
In order to solve the above technical problem, the present application provides a synchronous phasor measurement method, including:
acquiring a power signal, and adding an absolute time scale output by a 5G clock to the power signal;
acquiring an amplitude-frequency response curve of the power signal;
determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal;
and calculating fundamental phasor parameters of the power signals through an algorithm corresponding to the state.
Preferably, the process of acquiring the amplitude-frequency response curve of the power signal specifically includes:
and acquiring an amplitude-frequency response curve of the power signal through FFT.
Preferably, the process of determining the state of the power signal according to the amplitude-frequency response curve specifically includes:
according to the amplitude-frequency response curve
Then, determining that the power signal contains an attenuated DC component;
according to the amplitude-frequency response curve
Determining that the power signal contains a harmonic component or an inter-harmonic component;
according to the amplitude-frequency response curve
When the power signal contains an amplitude modulation signal and/or a phase angle modulation signal, judging that the power signal contains the amplitude modulation signal and/or the phase angle modulation signal;
wherein M (0) is the amplitude of frequency point 0, and M (f)1) Is a frequency point f1Amplitude of (d), M (f)2) Is a frequency point f2Amplitude of (d), M (f)3) Is a frequency point f3The amplitude of the frequency point f1The frequency point f2The frequency point f3For adjacent frequency points, M (f)0Δ f) and M (f)0And + delta f) are the amplitudes of the left and right frequency points of the fundamental frequency in sequence.
Preferably, when the power signal contains the amplitude modulation signal and/or the phase angle modulation signal, the process of calculating the fundamental phasor parameter of the power signal by the algorithm corresponding to the state specifically includes:
performing windowing DFT transformation on the electric power signal, and establishing a signal model corresponding to the amplitude modulation signal and/or the phase angle modulation signal;
calculating fundamental phasor parameters of the power signal according to the signal model, wherein the fundamental phasor parameters comprise the amplitude of the fundamental phasor and the phase angle of the fundamental phasor.
Preferably, the signal model comprises a plurality of DFT transform results,
wherein the k-th DFT transform result is
Wherein: mk＝[Mk0 Mk1…MkK]，
Wherein n isiAs a function of the window, MkAnd XkIs a known parameter of the signal model, P is a parameter to be solved of the signal model, f0Is the fundamental frequency, I0Is the imaginary part of the fundamental phasor, R0Is the real part of the fundamental phasor, gkAre coefficients of a discrete fourier transform.
Preferably, the process of calculating the fundamental phasor parameter of the power signal according to the signal model specifically includes:
acquiring a real part and an imaginary part of the fundamental phasor according to the parameter to be solved;
calculating the amplitude of the fundamental phasor according to an amplitude calculation formula, and calculating the phase angle of the fundamental phasor according to a phase angle calculation formula, wherein the amplitude calculation formula is
The phase angle is calculated as
a0Is the fundamental wave phaseMagnitude of quantity, θ0Is the phase angle of the fundamental phasor.
In order to solve the above technical problem, the present application further provides a synchronized phasor measurement system, including:
the acquisition module is used for acquiring a power signal and adding an absolute time scale output by a 5G clock to the power signal;
the acquisition module is used for acquiring an amplitude-frequency response curve of the power signal;
the judging module is used for determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal;
and the calculation module is used for calculating the fundamental wave phasor parameter of the electric power signal through an algorithm corresponding to the state.
Preferably, the determination module includes:
a first judging module for judging whether the amplitude-frequency response curve is correct or not according to the amplitude-frequency response curve
Then, determining that the power signal contains an attenuated DC component;
according to the amplitude-frequency response curve
Determining that the power signal contains a harmonic component or an inter-harmonic component;
according to the amplitude-frequency response curve
When the power signal contains an amplitude modulation signal and/or a phase angle modulation signal, judging that the power signal contains the amplitude modulation signal and/or the phase angle modulation signal;
wherein M (0) is the amplitude of frequency point 0, and M (f)1) Is a frequency point f1Amplitude of (d), M (f)2) Is a frequency point f2Amplitude of (d), M (f)3) Is a frequency point f3The amplitude of the frequency point f1The frequency point f2The frequency point f3For adjacent frequency points, M (f)0Δ f) and M (f)0And + delta f) are the amplitudes of the left and right frequency points of the fundamental frequency in sequence.
In order to solve the above technical problem, the present application further provides a synchronized phasor measurement apparatus, including:
a memory for storing a computer program;
a processor for implementing the steps of the synchrophasor measurement method according to any one of the above when executing the computer program.
To solve the above technical problem, the present application further provides a computer-readable storage medium, having a computer program stored thereon, where the computer program, when executed by a processor, implements the steps of the synchrophasor measurement method according to any one of the above.
The application provides a synchronous phasor measurement method, which comprises the following steps: acquiring a power signal, and adding an absolute time scale output by a 5G clock to the power signal; acquiring an amplitude-frequency response curve of the power signal; determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal; and calculating fundamental phasor parameters of the power signals through an algorithm corresponding to the state.
In practical application, the scheme of the application is adopted, the 5G with short delay, high reliability, high-precision time synchronization, high bandwidth and other superior communication performances is adopted in the synchronous phasor measurement device for data transmission, the requirement of the distribution network synchronous phasor measurement device for transmission delay can be met, meanwhile, time synchronization is carried out through the 5G, the input of a GPS and the input of communication such as optical fibers are saved, the cost of the synchronous phasor measurement device is saved, inter-harmonic waves, attenuation direct current components, amplitude modulation and phase angle modulation of electric power signals can be accurately identified, corresponding algorithms are adopted to calculate fundamental phasor parameters, the synchronous phasor measurement precision is high, and the application effect of distribution network wide area protection advanced measurement and control application is improved.
The application also provides a synchronized phasor measurement system, a synchronized phasor measurement device and a computer readable storage medium, and the synchronized phasor measurement system, the synchronized phasor measurement device and the computer readable storage medium have the same beneficial effects as the synchronized phasor measurement method.
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In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the prior art and the embodiments are briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a flow chart illustrating the steps of a synchrophasor measurement method provided herein;
fig. 2 is a schematic structural diagram of a time synchronization accuracy test of a 5G-based synchrophasor measurement apparatus provided by the present application;
FIG. 3 is a schematic diagram of a bandwidth and basic function test system provided in the present application;
fig. 4 is a schematic structural diagram of a delay test system provided in the present application;
FIG. 5 is a 5G delay-based external field test curve provided by the present application;
FIG. 6 is a comparison graph of the waveforms calculated by the present application, the waveforms calculated by the conventional DFT algorithm, and the true results;
fig. 7 is a schematic structural diagram of a synchronized phasor measurement system provided in the present application.
Detailed Description
The core of the application is to provide a synchronous phasor measurement method, a system and related components, the requirement of a distribution network synchronous phasor measurement device on transmission delay is met, the investment of a GPS and the investment of communication such as optical fibers are saved, the cost of the synchronous phasor measurement device is saved, the measurement precision is high, and the application effect of wide-area measurement and control of a distribution network and protection of advanced application can be improved.
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Referring to fig. 1, fig. 1 is a flowchart illustrating steps of a synchrophasor measurement method according to the present application, including:
step 1: acquiring a power signal, and adding an absolute time scale output by a 5G clock to the power signal;
specifically, the scheme of the application is applied to the synchrophasor measurement device, and firstly, a time setting signal output by a 5G time setting module is accessed into the synchrophasor measurement device so as to add an absolute time scale output by a 5G clock to an acquired power signal. It is understood that the power signal herein actually refers to the power signal within the target data window, and each sampling point within the target data window is given an absolute time scale based on 5G.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a time synchronization precision test of a synchrophasor measurement apparatus based on 5G provided in the present application, in which 2 TUE second pulses based on 5G time synchronization and a standard GPS second pulse are compared, errors of the 2 TUE and standard GPS second pulses are within 300ns, and a current national standard requires 1us for the time synchronization precision of the synchrophasor measurement apparatus, so that the time synchronization precision based on 5G meets an index requirement of the synchrophasor measurement apparatus. Referring to fig. 3, fig. 3 is a schematic structural diagram of a bandwidth and basic function testing system, according to the field test result, it can be known that a synchronous phasor measurement apparatus based on 5G still can meet the bandwidth requirement at 1000kbps (i.e. under the limit condition of calling recorded wave data without any limitation), and the voltage and current values can be accurately displayed in real time at the master station by adding the phasor measurement apparatus on the field through a relay protection tester. Referring to fig. 4, fig. 4 is a schematic structural diagram of a delay test system provided in the present application, where a communication delay of a whole network is tested by a delay test in a PING process of a synchronous phasor measurement device and a remote master station, and a test result of a 1627 packet test packet is as shown in fig. 5, a maximum bidirectional delay obtained by calculation is 13.727ms, an average bidirectional delay is 10.7294, a root mean square delay is 10.7600, and a packet loss rate is 0. Therefore, the current delay is less than 14ms (the unidirectional delay from the PMU to the main station is less than 7ms), which can meet the requirement of the synchronous phasor measurement device on communication delay. In summary, the synchronization of the synchronized phasor measurement apparatus is completed by the 5G synchronization module, so that the problems of difficulty in installation of the on-site GPS antenna and cost of the GPS apparatus are solved, and the requirements of the synchronized phasor measurement apparatus on the reliability, bandwidth and transmission delay of communication can be met.
Specifically, compared with 4G communication, 5G has the advantages of shorter delay, extremely high reliability, high-precision time setting, extremely high bandwidth and the like, and provides a basis for subsequently improving the accuracy of synchronous phasor measurement.
Step 2: acquiring an amplitude-frequency response curve of the power signal;
it can be understood that the power signal obtained in step 1 is a signal in a time domain, and in order to facilitate analysis of the power signal, the power signal obtained in step 1 is converted into a signal in a frequency domain, and an amplitude-frequency response curve of the power signal is obtained. Specifically, the conversion from the time domain signal to the frequency domain signal can be realized through Fast Fourier Transformation (FFT), the FFT operation speed is high, and a basis is provided for improving the efficiency of the synchrophasor measurement.
And step 3: determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal;
specifically, whether the power signal contains an attenuated direct current component and/or an inter-harmonic component or a harmonic component and/or an amplitude modulation signal and/or a phase angle modulation signal and the like can be determined according to the amplitude-frequency response curve.
Specifically, if the amplitude at 0Hz of the amplitude-frequency response curve is greater than 0 and the amplitudes of three adjacent frequency points are in decreasing relation, the requirement is met
Then, the current power signal is determined to containHas an attenuated DC component; if the amplitude of any frequency point is far larger than the amplitudes of the frequency points at two sides in the amplitude-frequency response curve, the requirement is met
It is determined that the power signal contains a frequency f2Inter-or harmonic of (i) when f2When the frequency is an integral multiple of the fundamental frequency, f is determined2Is the harmonic frequency when f2At a non-integral multiple fundamental frequency, f is determined2Is the inter-harmonic frequency; if the left and right frequency points of the fundamental wave are both greater than 0 and the values are approximately equal in the amplitude-frequency response curve, the requirement is met
It is determined that amplitude and phase angle modulated signals are present in the power signal. Wherein M (0) is the amplitude of frequency point 0, and M (f)1) Is a frequency point f1Amplitude of (d), M (f)2) Is a frequency point f2Amplitude of (d), M (f)3) Is a frequency point f3Amplitude, frequency point f1Frequency point f2Frequency point f3For adjacent frequency points, M (f)0Δ f) and M (f)0And + delta f) are the amplitudes of the left and right frequency points of the fundamental frequency in sequence.
And 4, step 4: and calculating fundamental phasor parameters of the power signals through an algorithm corresponding to the state.
Specifically, when the power signal is in different states, different algorithms may be used to calculate fundamental phasor parameters of the power signal, where the fundamental phasor parameters include a phase angle and a magnitude of a fundamental phasor. The algorithm for calculating the fundamental wave phasor parameters is selected according to the state of the power signal, so that the precision of synchronous phasor measurement can be further improved, and the accuracy is higher.
The application provides a synchronous phasor measurement method, which comprises the following steps: acquiring a power signal, and adding an absolute time scale output by a 5G clock to the power signal; acquiring an amplitude-frequency response curve of the power signal; determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal; and calculating fundamental phasor parameters of the power signals through an algorithm corresponding to the state.
In practical application, the scheme of the application is adopted, the 5G with short delay, high reliability, high-precision time synchronization, high bandwidth and other superior communication performances is adopted in the synchronous phasor measurement device for data transmission, the requirement of the distribution network synchronous phasor measurement device for transmission delay can be met, meanwhile, time synchronization is carried out through the 5G, the input of a GPS and the input of communication such as optical fibers are saved, the cost of the synchronous phasor measurement device is saved, inter-harmonic waves, attenuation direct current components, amplitude modulation and phase angle modulation of electric power signals can be accurately identified, corresponding algorithms are adopted to calculate fundamental phasor parameters, the synchronous phasor measurement precision is high, and the application effect of distribution network wide area protection advanced measurement and control application is improved.
On the basis of the above-described embodiment:
as a preferred embodiment, when the power signal contains an amplitude modulation signal and/or a phase angle modulation signal, the process of calculating the fundamental phasor parameter of the power signal by the algorithm corresponding to the state specifically includes:
performing windowing DFT conversion on the electric power signal, and establishing a signal model corresponding to the amplitude modulation signal and/or the phase angle modulation signal;
and calculating fundamental wave phasor parameters of the electric power signal according to the signal model, wherein the fundamental wave phasor parameters comprise the amplitude value of the fundamental wave phasor and the phase angle of the fundamental wave phasor.
As a preferred embodiment, the signal model comprises a multiple DFT (Discrete Fourier Transform) Transform result, wherein the k-th DFT Transform result is
Wherein: mk＝[Mk0 Mk1…MkK]，
Wherein n isiAs a function of the window, MkAnd XkIs a known parameter of the signal model, P is a parameter to be solved of the signal model, f0Is the fundamental frequency, I0Is the imaginary part of the fundamental phasor, R0Is the real part of the fundamental phasor, gkAre coefficients of a discrete fourier transform.
As a preferred embodiment, the process of calculating the fundamental phasor parameter of the power signal according to the signal model specifically includes:
acquiring a real part and an imaginary part of a fundamental phasor according to a parameter to be solved;
calculating the amplitude of the fundamental phasor according to an amplitude calculation formula, and calculating the phase angle of the fundamental phasor according to a phase angle calculation formula, wherein the amplitude calculation formula is
The phase angle is calculated as
a0Is the amplitude of the fundamental phasor, θ0Is the phase angle of the fundamental phasor.
Specifically, when the current power signal is identified to contain an amplitude value and a phase angle modulation signal, the application provides a multi-stage taylor series frequency domain algorithm based on center frequency self-adaptive adjustment so as to accurately calculate a fundamental wave value of a synchronous phasor during amplitude phase angle modulation, and the specific steps include:
1. assume that the power signal model is:
during amplitude and phase angle modulation, the amplitude and the phase angle are sine functions, and the amplitude and the phase angle are approximately expressed by adopting a multi-stage Taylor series.
2. Assuming that the power signal amplitude, phase angle polynomial form is expressed as:
P(t)＝a(t)ejθ(t)
in the formula
And
representing the power system voltage or current signal magnitude and phase angle, respectively.
3. Performing DFT conversion on the power signal:
DFT transform coefficients to
In the formula gkRepresenting the coefficients of discrete Fourier transform, in which the window function is a rectangular window, resulting in the coefficient gkThe following equation:
4. the complex field equation is expanded into real and imaginary forms:
in the formula: xk＝[XkR XkI]TCalculating a result for the kth Fourier transform; mk＝[Mk0 Mk1…MkK]Is the coefficient of the equation set;
5. And (3) simultaneous equations to obtain signal model parameters:
in the formula: x ═ X0 T X1 T…XK T]T；M＝[M0 T M1 T…MK T]T；
6. And (3) solving the amplitude and the phase angle of the fundamental phasor:
7. and (3) self-adaptive adjustment of frequency:
after calculating the fundamental frequency of the power signal by using the prior art, the fundamental frequency f in the algorithm is calculated0And carrying out self-adaptive adjustment.
Specifically, assuming that a phase angle modulation signal with an amplitude of 5 ° and a modulation frequency of 4.5Hz is superimposed in the power signal, and an amplitude modulation signal with an amplitude of 0.1 and a modulation frequency of 4.5Hz is superimposed at the same time, the mathematical expression of the power signal is as follows:
in the formula: a is the fundamental amplitude, and 1 is taken in the embodiment; f. of0For the fundamental frequency, this embodiment takes 50 Hz; a isdFor amplitude modulation, this embodiment takes 0.1; f. ofdFor amplitude modulation frequency, this example takes 4.5 Hz;
the phase angle is amplitude modulation, and 0 degree is taken in the embodiment; a isaIs a phase angleModulating amplitude, taking 5 degrees in the embodiment; f. ofaThe amplitude modulation frequency is 4.5Hz in this example;
in this embodiment, the phase angle of the phase angle modulation is 0 °.
Under the condition of simultaneously superposing amplitude and phase angle modulation, the calculation result based on the scheme provided by the application is shown in fig. 6, the calculation result in fig. 6 comprises the waveform calculated by the application, the waveform calculated by the traditional DFT algorithm and the true value result, and the algorithm precision provided by the application is higher than that of the traditional algorithm as can be seen from fig. 6.
The error based on the calculation result of the present application and the error of the traditional DFT algorithm are shown in Table 1, Table 1 is a comparison table of the calculation results of the traditional DFT algorithm and the algorithm of the present invention, and it can be seen from Table 1 that the method provided by the present application has high precision, the maximum phase angle error is 0.005613, the maximum amplitude error is-0.02%, and the requirements of national standards are met.
TABLE 1 comparison of calculation results for conventional DFT algorithm and the algorithm of the present invention
In summary, the method accurately identifies the inter-harmonic, attenuation direct current component, amplitude modulation and phase angle modulation process of the electric power signal through frequency spectrum self-adaptive identification, adopts corresponding technology to calculate when identifying that the electric power signal contains the harmonic, inter-harmonic and attenuation direct current component, provides a multi-stage Taylor series frequency domain algorithm based on center frequency self-adaptive adjustment aiming at the amplitude modulation and the phase angle modulation, and can accurately calculate the amplitude and the phase angle of the fundamental wave phasor. The synchronous Phasor Measurement device based on 5G completely meets the requirements of a power distribution network, and with the popularization of a PMU (Phasor Measurement Unit) device and a 5G technology, the combination of PMU and 5G is an inevitable trend in PMU development. Because the investment of GPS and the investment of communication such as optical fiber and the like are saved, the cost of PMU popularization is greatly saved. The 5G excellent communication performance comprises short time delay, extremely high reliability, high-precision time setting, extremely high bandwidth and the like, provides communication and time setting basis for the application of the PMU in a new scene of a power grid, and opens a new situation for the popularization of the PMU in the power grid.
Referring to fig. 7, fig. 7 is a schematic structural diagram of a synchronized phasor measurement system provided in the present application, including:
the acquisition module 1 is used for acquiring a power signal and adding an absolute time scale output by a 5G clock to the power signal;
the acquisition module 2 is used for acquiring an amplitude-frequency response curve of the power signal;
the judging module 3 is used for determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or comprises an inter-harmonic component or a harmonic component, and/or comprises an amplitude modulation signal and/or a phase angle modulation signal;
and the calculation module 4 is used for calculating the fundamental wave phasor parameters of the power signals through an algorithm corresponding to the state.
As a preferred embodiment, the determination module 3 includes:
a first decision module 3 for determining the frequency response curve according to the amplitude-frequency response curve
Judging that the power signal contains an attenuated direct-current component;
according to the amplitude-frequency response curve when
Judging that the power signal contains a harmonic component or an inter-harmonic component;
according to the amplitude-frequency response curve when
Judging that the power signal contains an amplitude modulation signal and/or a phase angle modulation signal;
wherein M (0) is the amplitude of frequency point 0, and M (f)1) Is a frequency point f1Amplitude of (d), M (f)2) Is a frequency point f2Amplitude of (d), M (f)3) Is a frequency point f3Amplitude, frequency point f1Frequency point f2Frequency point f3For adjacent frequency points, M (f)0Δ f) and M (f)0And + delta f) are the amplitudes of the left and right frequency points of the fundamental frequency in sequence.
As a preferred embodiment, when the power signal contains an amplitude modulation signal and/or a phase angle modulation signal, the calculation module 4 is specifically configured to:
performing windowing DFT conversion on the electric power signal, and establishing a signal model corresponding to the amplitude modulation signal and/or the phase angle modulation signal;
and calculating fundamental wave phasor parameters of the electric power signal according to the signal model, wherein the fundamental wave phasor parameters comprise the amplitude value of the fundamental wave phasor and the phase angle of the fundamental wave phasor.
As a preferred embodiment, the signal model comprises a plurality of DFT transform results, wherein the k-th DFT transform result is
Wherein: mk＝[Mk0 Mk1…MkK]，
Wherein n isiAs a function of the window, MkAnd XkIs a known parameter of the signal model, P is a parameter to be solved of the signal model, f0Is the fundamental frequency, I0Is the imaginary part of the fundamental phasor, R0Is the real part of the fundamental phasor, gkAre coefficients of a discrete fourier transform.
As a preferred embodiment, the process of calculating the fundamental phasor parameter of the power signal according to the signal model specifically includes:
acquiring a real part and an imaginary part of a fundamental phasor according to a parameter to be solved;
calculating the amplitude of the fundamental phasor according to an amplitude calculation formula, and calculating the phase angle of the fundamental phasor according to a phase angle calculation formula, wherein the amplitude calculation formula is
The phase angle is calculated as
a0Is the amplitude of the fundamental phasor, θ0Is the phase angle of the fundamental phasor.
The application also provides a synchronized phasor measurement system which has the same beneficial effects as the synchronized phasor measurement method.
For an introduction of the synchronized phasor measurement system provided by the present application, please refer to the above embodiments, which are not described herein again.
Correspondingly, this application still provides a synchrophasor measuring device, includes:
a memory for storing a computer program;
a processor for implementing the steps of the synchrophasor measurement method as any one of the above when executing a computer program.
The application also provides a synchronous phasor measurement device which has the same beneficial effect as the synchronous phasor measurement method.
Please refer to the above embodiments for the introduction of a synchronized phasor measurement apparatus provided in the present application, which is not described herein again.
Accordingly, the present application also provides a computer readable storage medium having a computer program stored thereon, which when executed by a processor, performs the steps of the synchrophasor measurement method as any one of the above.
The present application also provides a computer-readable storage medium having the same advantageous effects as the above-described synchronized phasor measurement method.
For the introduction of a computer-readable storage medium provided in the present application, please refer to the above embodiments, which are not described herein again.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The description of the synchrophasor measurement system and the synchrophasor measurement device disclosed in the embodiments is relatively simple because it corresponds to the synchrophasor measurement method disclosed in the embodiments, and the relevant points can be referred to the description of the synchrophasor measurement method.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (8)
1. A synchrophasor measurement method, comprising:
acquiring a power signal, and adding an absolute time scale output by a 5G clock to the power signal;
acquiring an amplitude-frequency response curve of the power signal;
determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal;
calculating a fundamental phasor parameter of the power signal through an algorithm corresponding to the state;
the process of determining the state of the power signal according to the amplitude-frequency response curve specifically comprises the following steps:
according to the amplitude-frequency response curve
Then, determining that the power signal contains an attenuated DC component;
according to the amplitude-frequency response curve
Determining that the power signal contains a harmonic component or an inter-harmonic component;
according to the amplitude-frequency response curve
When the power signal contains an amplitude modulation signal and/or a phase angle modulation signal, judging that the power signal contains the amplitude modulation signal and/or the phase angle modulation signal;
wherein M (0) is the amplitude of frequency point 0, and M (f)1) Is a frequency point f1Amplitude of (d), M (f)2) Is a frequency point f2Amplitude of (d), M (f)3) Is a frequency point f3The amplitude of the frequency point f1The frequency point f2The frequency point f3For adjacent frequency points, M (f)0Δ f) and M (f)0And + delta f) are the amplitudes of the left and right frequency points of the fundamental frequency in sequence.
2. The synchrophasor measurement method according to claim 1, wherein the process of acquiring the amplitude-frequency response curve of the power signal is specifically:
and acquiring an amplitude-frequency response curve of the power signal through FFT.
3. A synchrophasor measurement method according to claim 1, wherein when said power signal contains said amplitude modulation signal and/or said phase angle modulation signal, said process of calculating fundamental phasor parameters of said power signal by an algorithm corresponding to said state is specifically:
performing windowing DFT transformation on the electric power signal, and establishing a signal model corresponding to the amplitude modulation signal and/or the phase angle modulation signal;
calculating fundamental phasor parameters of the power signal according to the signal model, wherein the fundamental phasor parameters comprise the amplitude of the fundamental phasor and the phase angle of the fundamental phasor.
4. A synchrophasor measurement method according to claim 3, wherein the signal model comprises a plurality of DFT results, wherein the kth DFT result is
Wherein: mk＝[Mk0 Mk1 … MkK]，
Wherein n isiAs a function of the window, MkAnd XkIs a known parameter of the signal model, P is a parameter to be solved of the signal model, f0Is the fundamental frequency, I0Is the imaginary part of the fundamental phasor, R0Is the real part of the fundamental phasor, gkAre coefficients of a discrete fourier transform.
5. The synchrophasor measurement method according to claim 4, wherein said process of calculating fundamental phasor parameters of said power signal according to said signal model is specifically:
acquiring a real part and an imaginary part of the fundamental phasor according to the parameter to be solved;
calculating the amplitude of the fundamental phasor according to an amplitude calculation formula, and calculating the phase angle of the fundamental phasor according to a phase angle calculation formula, wherein the amplitude calculation formula is
The phase angle is calculated as
a0Is the amplitude of the fundamental phasor, θ0Is the phase angle of the fundamental phasor.
6. A synchronized phasor measurement system, comprising:
the acquisition module is used for acquiring a power signal and adding an absolute time scale output by a 5G clock to the power signal;
the acquisition module is used for acquiring an amplitude-frequency response curve of the power signal;
the judging module is used for determining the state of the power signal according to the amplitude-frequency response curve, wherein the state comprises an attenuated direct current component, and/or an inter-harmonic component or a harmonic component, and/or an amplitude modulation signal and/or a phase angle modulation signal;
the calculation module is used for calculating fundamental wave phasor parameters of the power signals through an algorithm corresponding to the state;
the determination module includes:
a first determination module to:
according to the amplitude-frequency response curve
Then, determining that the power signal contains an attenuated DC component;
according to the amplitude-frequency response curve
Determining that the power signal contains a harmonic component or an inter-harmonic component;
according to the amplitude-frequency response curve
When the power signal contains an amplitude modulation signal and/or a phase angle modulation signal, judging that the power signal contains the amplitude modulation signal and/or the phase angle modulation signal;
wherein M (0) is the amplitude of frequency point 0, and M (f)1) Is a frequency point f1Amplitude of (d), M (f)2) Is a frequency point f2Amplitude of (d), M (f)3) Is a frequency point f3The amplitude of the frequency point f1Said frequencyPoint of rate f2The frequency point f3For adjacent frequency points, M (f)0Δ f) and M (f)0And + delta f) are the amplitudes of the left and right frequency points of the fundamental frequency in sequence.
7. A synchronized phasor measurement apparatus, comprising:
a memory for storing a computer program;
a processor for implementing the steps of the synchrophasor measurement method according to any of claims 1-5 when executing the computer program.
8. A computer-readable storage medium, having stored thereon a computer program which, when being executed by a processor, carries out the steps of the synchrophasor measurement method according to any one of claims 1-5.
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| CN111650469B (en) * | 2020-05-14 | 2021-11-16 | 南方电网科学研究院有限责任公司 | D-PMU device-based power distribution network fault accurate positioning method |
| CN111624441B (en) * | 2020-06-10 | 2022-02-18 | 国网四川省电力公司电力科学研究院 | PMU measurement error analysis method under influence of low-frequency oscillation |
| CN112748284A (en) * | 2020-12-30 | 2021-05-04 | 清华大学 | Method and device for measuring synchronous waveform and broad-spectrum phasor of power system |
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