A short-circuit current setting calculation simulation checking method, system, device and medium based on Gaussian filtering

Abstract

The application discloses a short-circuit current setting calculation simulation checking method, system and device based on Gaussian filtering and a medium, belongs to the technical field of short-circuit current setting calculation, and comprises the following steps: collecting three-phase current signals of a fault point, performing frequency shift filtering processing on the three-phase current signals, and obtaining filtered complex signals; extracting power frequency parameters of the fault current by means of a power frequency phasor estimation method, performing energy normalization processing on the filtered complex signals, and obtaining normalized complex signals; calculating the amplitude and phase of three-phase power frequency phasors from the normalized complex signals by means of a complex analytic method; performing sequence component conversion calculation according to the three-phase power frequency phasors, obtaining positive sequence components, negative sequence components and zero sequence components, and realizing extraction of the power frequency parameters of the fault current. The application solves the comparability problem between electromagnetic transient simulation results and setting calculation results, efficiently realizes a finite impulse response filter, considers calculation real-time performance, and meets the demand of fast checking of a large-scale power grid.

Description

Technical Field

[0001] This invention relates to the field of short-circuit current setting calculation technology, specifically to a method, system, device, and medium for short-circuit current setting calculation simulation verification based on Gaussian filtering. Background Technology

[0002] The reliability of power system relay protection setting calculations directly depends on the accuracy of short-circuit current calculations. Currently, the industry commonly uses setting software (such as RelayCAC, PSASP, and DIGSI) for short-circuit calculations. This software is based on an equivalent model of the subtransient parameters of a synchronous generator and obtains the initial value of the power frequency fundamental wave (subtransient current) through steady-state AC circuit solutions. However, the fault current output by electromagnetic transient simulation tools (such as EMTP and PSCAD) is instantaneous waveform data containing high-frequency harmonics and attenuated DC components. Its physical form differs fundamentally from the steady-state amplitude / phase results output by the setting software. This difference makes direct comparison between the two types of results impossible. Traditional power frequency extraction methods (such as full-cycle Fourier transform) will produce amplitude deviations exceeding 5% and phase shifts exceeding 2° under non-periodic component interference, severely limiting the reliability of the setting calculation results. Summary of the Invention

[0003] In view of the above-mentioned problems, the present invention provides a method, system, device and medium for short-circuit current setting calculation, simulation and verification based on Gaussian filtering.

[0004] Therefore, the technical problem solved by this invention is: how to resolve the essential difference between the physical form of the electromagnetic transient simulation tool and the steady-state amplitude / phase results output by the tuning software.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a short-circuit current setting calculation simulation verification method based on Gaussian filtering, comprising: acquiring three-phase current signals at the fault point; performing frequency shift filtering on the three-phase current signals to obtain filtered complex signals; extracting fault current power frequency parameters using a power frequency phasor estimation method; performing energy normalization processing on the filtered complex signals to obtain normalized complex signals; calculating the amplitude and phase of the three-phase power frequency phasors from the normalized complex signals using a complex number analytical method; and performing sequence component conversion calculation based on the three-phase power frequency phasors to obtain positive sequence components, negative sequence components, and zero sequence components, thereby realizing the extraction of fault current power frequency parameters.

[0006] As a preferred embodiment of the short-circuit current setting calculation simulation verification method based on Gaussian filtering described in this invention, the following steps are included: acquiring the three-phase current signals at the fault point and performing frequency-shift filtering on the three-phase current signals to obtain filtered complex signals. This includes performing an orthogonal frequency shift operation on each phase current signal to convert the power frequency component into a zero frequency component, thereby obtaining the frequency-shifted three-phase current signals; designing a Gaussian low-pass filter and determining the cutoff frequency based on the power frequency and stopband attenuation; and designing a finite impulse response Gaussian filter using the window function method and performing a convolution operation on the frequency-shifted three-phase current signals to obtain the filtered complex signals.

[0007] As a preferred embodiment of the short-circuit current setting calculation simulation verification method based on Gaussian filtering described in this invention, the step of extracting the power frequency parameters of the fault current using the power frequency phasor estimation method and performing energy normalization processing on the filtered complex signal to obtain the normalized complex signal includes: selecting a window of a preset time length, using a point-by-point sliding window method to calculate the signal energy within the window at each moment of the filtered complex signal starting from the signal start time; and performing normalization processing on the filtered complex signal based on the signal energy within the window corresponding to each moment to obtain the normalized complex signal.

[0008] As a preferred embodiment of the short-circuit current setting calculation simulation verification method based on Gaussian filtering described in this invention, the step of calculating the amplitude and phase of the three-phase power frequency phasors from the normalized complex signal using a complex analytical method includes: modeling the normalized complex signal into a complex form containing time-varying amplitude and time-varying phase; and extracting the power frequency phasors from the normalized complex signal using a complex analytical method to obtain the amplitude and phase.

[0009] As a preferred embodiment of the short-circuit current setting calculation simulation verification method based on Gaussian filtering described in this invention, the design of the Gaussian low-pass filter, which determines the cutoff frequency based on the power frequency and stopband attenuation, includes: the cutoff frequency ensuring that the signal attenuation of the Gaussian low-pass filter at the power frequency reaches below a preset threshold; and the cutoff frequency ensuring that the error tolerance of the Gaussian low-pass filter within the preset frequency offset range of the passband is lower than a preset value.

[0010] This preferred solution determines the cutoff frequency through dual constraints, which can both ensure that the influence of the attenuated DC component is attenuated to a negligible level at the power frequency and adapt to the frequency deviation in actual power grid operation, thereby improving the filter's engineering applicability and resistance to frequency fluctuations.

[0011] As a preferred embodiment of the short-circuit current setting calculation simulation verification method based on Gaussian filtering described in this invention, the step of selecting a window of a preset time length and using a point-by-point sliding window method to calculate the signal energy within the window at each moment of the filtered complex signal includes: selecting a window of a preset time length and sliding the window point by point from the moment of the signal start; performing calculations on the filtered complex signal within each window to obtain the signal energy within the window at each moment; and normalizing the filtered complex signal based on the signal energy within the window corresponding to each moment.

[0012] This preferred scheme calculates energy point by point using a sliding window and normalizes it, which can suppress amplitude fluctuations caused by sudden changes in the attenuation DC component at fault moments, effectively eliminate non-periodic components, and improve the accuracy of power frequency parameter extraction.

[0013] As a preferred embodiment of the short-circuit current setting calculation simulation verification method based on Gaussian filtering described in this invention, the step of performing sequence component conversion calculation based on three-phase power frequency phasors to obtain positive sequence component, negative sequence component, and zero sequence component, and realizing the extraction of fault current power frequency parameters, includes: using the symmetrical component method to calculate the positive sequence component based on the three-phase power frequency phasors and preset transformation coefficients; calculating the negative sequence component based on the three-phase power frequency phasors and preset transformation coefficients; and calculating the zero sequence component based on the three-phase power frequency phasors and preset transformation coefficients.

[0014] This preferred solution uses the symmetrical component method to directly calculate the three sequence components through preset transformation coefficients, which can accurately obtain the positive sequence, negative sequence and zero sequence components of the fault current.

[0015] This invention provides a short-circuit current setting calculation, simulation, and verification system based on Gaussian filtering.

[0016] To solve the above technical problems, the present invention provides the following technical solution: a short-circuit current setting calculation simulation verification system based on Gaussian filtering, comprising: a frequency shift filtering module, an energy normalization module, a phasor calculation module, and a sequence component conversion module; the frequency shift filtering module is used to collect the three-phase current signal at the fault point, and perform frequency shift filtering on the three-phase current signal to obtain a filtered complex signal; the energy normalization module is used to extract the fault current power frequency parameters through a power frequency phasor estimation method, and perform energy normalization on the filtered complex signal to obtain a normalized complex signal; the phasor calculation module is used to calculate the amplitude and phase of the three-phase power frequency phasors from the normalized complex signal through a complex number analytical method; the sequence component conversion module is used to perform sequence component conversion calculation based on the three-phase power frequency phasors to obtain positive sequence components, negative sequence components, and zero sequence components, thereby realizing the extraction of fault current power frequency parameters.

[0017] The present invention provides a computer device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the aforementioned method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering.

[0018] The present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the aforementioned method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering.

[0019] The beneficial effects of this invention are as follows: By employing innovative Gaussian filtering for power frequency feature extraction and dynamic phasor estimation techniques, the comparability problem between electromagnetic transient simulation results and tuning calculation results is fundamentally solved. Compared to traditional verification methods, its core advantage lies in achieving a balance between high precision, strong robustness, and engineering practicality. In terms of accuracy, the synergistic design of quadrature frequency shift and zero-phase-shift Gaussian filtering effectively eliminates the interference of attenuated DC components and high-frequency harmonics on power frequency characteristics, ensuring that the extracted current amplitude and phase parameters truly reflect the short-circuit steady-state characteristics, and significantly reducing amplitude fluctuations and phase shifts caused by aperiodic components. In terms of robustness, the phasor estimation mechanism based on sliding window energy normalization eliminates the influence of transient processes on power frequency parameter estimation by dynamically adapting to changes in signal energy, enabling the method to maintain stable performance even in complex power grid scenarios with a high proportion of new energy sources. Simultaneously, the efficient implementation of the finite-length impulse response filter ensures real-time computation, meeting the needs of rapid verification for large-scale power grids. Furthermore, the sequence component verification strategy, centered on positive sequence current, closely aligns with the actual needs of relay protection settings, providing differentiated verification focuses for different fault types. The overall technical solution does not rely on specific simulation platforms or setting software interfaces, demonstrating broad engineering applicability and providing a universal solution for the reliability verification of short-circuit current calculations in power systems. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 The following is a flowchart of a short-circuit current setting calculation, simulation and verification method based on Gaussian filtering, provided as an embodiment of the present invention.

[0022] Figure 2 A typical example of a simulation verification method for short-circuit current setting based on Gaussian filtering, provided in an embodiment of the present invention, is the main wiring diagram for setting calculation modeling. Figure 1 .

[0023] Figure 3 A typical example of a simulation verification method for short-circuit current setting based on Gaussian filtering, provided in an embodiment of the present invention, is the main wiring diagram for setting calculation modeling. Figure 2 . Detailed Implementation

[0024] To make the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0025] Example 1, referring to Figure 1 This is one embodiment of the present invention, which provides a method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering, including: S1. Collect the three-phase current signal at the fault point, perform frequency shift filtering on the three-phase current signal, and obtain the filtered complex signal.

[0026] S2. Extract the fault current power frequency parameters using the power frequency phasor estimation method, and perform energy normalization processing on the filtered complex signal to obtain the normalized complex signal.

[0027] S3. Calculate the amplitude and phase of the three-phase power frequency phasors from the normalized complex signal using the complex number analysis method.

[0028] S4. Perform sequence component conversion calculations based on the three-phase power frequency phasors to obtain the positive sequence component, negative sequence component, and zero sequence component, thereby realizing the extraction of power frequency parameters of fault current.

[0029] It should be noted that in the calculation of power system relay protection settings, accurately obtaining the power frequency parameters of the fault current is the foundation for the correct operation of the protection device. In actual power grid fault processes, the fault current signal contains power frequency components, attenuated DC components, and high-frequency interference components. Traditional Fourier transform methods suffer from spectral leakage when processing fault signals containing attenuated DC components, resulting in insufficient accuracy in power frequency parameter extraction. At the same time, the power grid frequency in actual operation is not the ideal 50Hz, but has a frequency offset of ±2Hz, further affecting the accuracy of parameter extraction. In addition, the abrupt change in the attenuated DC component at the time of the fault will cause amplitude fluctuations, affecting the estimation accuracy of the power frequency phasor.

[0030] Therefore, to address the aforementioned issues of parameter extraction accuracy and anti-interference capability, steps S1-S4 are employed: orthogonal frequency shifting is used to convert the power frequency component into a zero-frequency component; a Gaussian low-pass filter is used to filter out interference, achieving effective separation of the power frequency component from the interference component; point-by-point sliding window energy normalization is used to eliminate the influence of abrupt changes in the attenuated DC component; the power frequency phasor is directly extracted based on a complex analytical method, avoiding the spectral leakage problem of the Fourier transform; finally, positive-sequence, negative-sequence, and zero-sequence components are obtained through sequence component conversion, achieving high-precision extraction of fault current power frequency parameters and providing reliable parameter basis for relay protection setting calculations.

[0031] Example 2, refer to Figure 2 and Figure 3 As an embodiment of the present invention, based on the previous embodiment, a method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering is provided, including: In this embodiment, the frequency shifting and filtering process in step S1 includes multiplying each phase current signal by a complex exponential operator to perform an orthogonal frequency shifting operation, converting the power frequency component into a zero frequency component, and obtaining the frequency-shifted three-phase current signal; designing a Gaussian low-pass filter, determining the cutoff frequency based on the power frequency and stopband attenuation; and designing a finite impulse response Gaussian filter using the window function method, performing a convolution operation on the frequency-shifted three-phase current signal to obtain the filtered complex signal.

[0032] In one alternative implementation, the frequency shift filtering process can also perform bandpass filtering on each phase current signal after frequency domain transformation, extract the power frequency component, and convert it into a time domain signal.

[0033] In another alternative implementation, the frequency shift filtering process can also use Hilbert transform to analyze the three-phase current signal, and combine it with a low-pass filter to filter out high-frequency interference components to obtain the filtered complex signal.

[0034] This invention converts the power frequency component into a zero frequency component through orthogonal frequency shifting, and shifts the attenuated DC component to near the power frequency, thereby achieving effective separation of the power frequency component and the interference component in the frequency domain. It also uses the exponential attenuation characteristic of a Gaussian low-pass filter to filter out noise without oscillation, avoids phase distortion, and improves the accuracy of power frequency parameter extraction and anti-interference capability.

[0035] Furthermore, in step S1, the three-phase current signal at the fault point is acquired, and the three-phase current signal is subjected to frequency shift filtering to obtain the filtered complex signal, including the following steps A1-A3: A1. Perform an orthogonal frequency shift operation on each phase current signal to convert the power frequency component into a zero frequency component, thus obtaining the frequency-shifted three-phase current signal.

[0036] A2. Design a Gaussian low-pass filter and determine the cutoff frequency based on the power frequency and stopband attenuation.

[0037] A3. A finite impulse response Gaussian filter is designed using the window function method. The frequency-shifted three-phase current signal is convolved to obtain the filtered complex signal.

[0038] In this embodiment of the application, the convolution operation in step A3 includes designing a finite impulse response Gaussian filter using the window function method, performing a convolution operation on the frequency-shifted three-phase current signal, filtering out non-power frequency interference, and obtaining a filtered complex signal.

[0039] In one alternative implementation, the convolution operation can also employ a frequency domain convolution method, which involves performing Fourier transforms on the frequency-shifted three-phase current signal and the filter transfer function respectively, multiplying them, and then performing an inverse Fourier transform to obtain the filtered complex signal.

[0040] In another alternative implementation, the convolution operation can also employ a fast convolution algorithm, which uses an overlapping addition method to perform segmented convolution processing on the frequency-shifted three-phase current signal to obtain a filtered complex signal.

[0041] This invention applies a finite impulse response Gaussian filter to the frequency-shifted three-phase current signal through convolution operation. It utilizes the exponential decay characteristic of the Gaussian filter to achieve smooth filtering, effectively filtering out interference components shifted to the high-frequency region and retaining the power frequency component at the zero frequency, thereby improving the accuracy of signal processing.

[0042] Specifically, by simulating a ground fault through electromagnetic transient simulation, the instantaneous signals of the three-phase currents during the fault period (sampling rate f) can be obtained. s (≥10kHz), this invention uses a numerical example to explain the method. The example is a two-terminal transmission structure, and the power sources at both ends are equivalent power sources. The parameters of the equivalent power sources at both ends and the line parameters used for electromagnetic transient simulation modeling are shown in Table 1 and Table 2, respectively.

[0043] Table 1 Equivalent parameters at both ends

[0044] Table 2 Line Parameters

[0045] After completing the electromagnetic transient simulation model based on the above parameters, the short-circuit current setting calculation simulation verification is performed using the three-phase current signal obtained after simulating a ground fault as input.

[0046] Specifically, in step A1, the quadrature frequency shift operation multiplies the current of each phase by a complex exponential operator. ( =2π×50rad / s), converting the 50Hz power frequency component to a zero-frequency DC component, expressed as: in, represents an imaginary number, Represents angular frequency. The value is the relative time corresponding to the sampling point. , , These represent the three-phase sampled current signals at the fault point. , , These represent the signals obtained after frequency shifting the sampled three-phase current signals. Since multiplying the signal by the complex exponential operator only changes the frequency and not the initial phase, the reference phase of the current signal will not change after frequency shifting.

[0047] Furthermore, in step A2, a Gaussian low-pass filter is designed, and the cutoff frequency is determined based on the power frequency and stopband attenuation, including the following steps A21-A22: A21. The cutoff frequency ensures that the signal attenuation of the Gaussian low-pass filter at the power frequency is below a preset threshold.

[0048] A22. The cutoff frequency ensures that the error tolerance of the Gaussian low-pass filter within the preset frequency offset range of the passband is lower than the preset value.

[0049] Specifically, the Gaussian low-pass filter parameters are designed in step A2: The amplitude-frequency response of the Gaussian filter is Cutoff frequency The principles for determining this are as follows: A decaying DC component is generated during a ground fault. Before calculating the power frequency current component during the fault, the influence of this decaying DC component needs to be eliminated as much as possible. After the quadrature frequency shift operation, the original power frequency component is shifted to zero frequency, and the decaying DC component is shifted to around 50Hz. Therefore, it is necessary to ensure that the Gaussian low-pass filter... When the signal attenuation reaches below 0.5%, based on practical engineering experience, the impact of spectral leakage of the interference signal is negligible when the interference signal strength attenuates to below 0.5%.

[0050] therefore Solving for: in, Indicates the cutoff frequency; Indicates the power frequency; This refers to stopband attenuation. Considering that the frequency in actual power grid operation is not an ideal 50Hz, and the frequency range that the power grid is usually allowed to operate stably is 50±2Hz, it is necessary to ensure that the filter's error tolerance within the ±2Hz range of the passband is less than 0.5%. The cutoff frequency needs to meet the following requirements. ,Sure .

[0051] Specifically, in step A3, the finite impulse response (FIR) Gaussian filter designed using the window function method is expressed as follows: in, The finite impulse response after applying a windowed function is... Control the pulse width; Indicates the sampling rate; Indicates the cutoff frequency; For window functions, choose the Kaiser window ( =5), suppressing truncated oscillations, filter order =330 (at a sampling rate of 10kHz), the window function is selected using the conventional engineering selection method.

[0052] Using an FIR Gaussian filter to perform convolution operation on the frequency-shifted three-phase current signal, taking phase A as an example: The other two phases are processed in the same way. The three-phase signals are filtered and processed in parallel, and the output is a complex signal that filters out non-power frequency interference. Frequency shifting moves the interference components to the high-frequency region, and Gaussian filtering removes noise without oscillation due to its exponential decay characteristics, avoiding phase distortion.

[0053] In this embodiment of the application, the energy normalization process in step S2 includes selecting a window of a preset time length, using a point-by-point sliding window method to calculate the signal energy within the window at each moment of the filtered complex signal starting from the signal start time; and performing normalization processing on the filtered complex signal based on the signal energy within the window corresponding to each moment to obtain the normalized complex signal.

[0054] In one alternative implementation, the energy normalization process can also employ a fixed window to segment the filtered complex signal, calculate the signal energy within each segment, and normalize it.

[0055] In another alternative implementation, the energy normalization process can also employ an adaptive window length, dynamically adjusting the window size according to the signal characteristics, calculating the energy of the filtered complex signal and performing normalization processing.

[0056] This invention calculates and normalizes the signal energy within a window using a point-by-point sliding window method, which can suppress amplitude fluctuations caused by sudden changes in the attenuated DC component at fault moments, effectively eliminate non-periodic components, and improve the accuracy and stability of power frequency phasor estimation.

[0057] Furthermore, in step S2, the fault current power frequency parameters are extracted using the power frequency phasor estimation method, and the filtered complex signal is subjected to energy normalization processing to obtain the normalized complex signal, including the following steps B1-B2: B1. Select a window with a preset time length, and use a point-by-point sliding window method to calculate the signal energy within the window at each moment of the filtered complex signal, starting from the initial moment of the signal.

[0058] B2. Based on the signal energy within the window corresponding to each time moment, the filtered complex signal is normalized to obtain the normalized complex signal.

[0059] In this embodiment of the application, the point-by-point sliding window method in step B1 includes selecting a window of a preset time length, sliding the window point by point from the start time of the signal, performing integration on the filtered complex signal in each window, and obtaining the signal energy in the window at each time.

[0060] In one alternative implementation, the point-to-point sliding window method can also employ a fixed-step sliding window method, sliding the window at preset time intervals to calculate the signal energy corresponding to each window position.

[0061] In another alternative implementation, the point-by-point sliding window method can also adopt an overlapping sliding window method, setting the window overlap rate, and processing the filtered complex signal through partially overlapping windows to obtain the signal energy at each time.

[0062] This invention processes the current signal point by point throughout the fault time, starting from the initial moment of the signal using a point-by-point sliding window method. This allows for real-time tracking of signal energy changes, suppression of amplitude fluctuations caused by sudden changes in the attenuated DC component at the fault moment, and dynamic elimination of aperiodic components.

[0063] Furthermore, in step B1, a window of a preset time length is selected, and a point-by-point sliding window method is used to calculate the signal energy within the window at each time point of the filtered complex signal, starting from the signal's initial moment. This includes the following steps B11-B13: B11. Select a window with a preset time length and slide the window point by point starting from the signal start time.

[0064] B12. Perform calculations on the filtered complex signal within each window to obtain the signal energy within the window at each time step.

[0065] B13. Normalize the filtered complex signal based on the signal energy within the window corresponding to each time moment.

[0066] Specifically, in step B1, the filtered complex signal (The filtered three-phase current signal is) , , Since all three phase signals are processed in parallel using the same method, The model (referencing) is as follows: in, The time-varying amplitude value, For time-varying phase, This is residual noise.

[0067] To eliminate the influence of aperiodic components, a window length of 20ms (Tw = 20ms) was selected, determined based on the power frequency period. For a 50Hz AC power frequency, the period is 20ms. A point-by-point sliding window method was used to filter the complex signal starting from the initial moment of the signal. Calculate the signal energy within the window at each time step: in, For signal energy within the window, Indicates the window length. Represents the integral variable. This represents the filtered complex signal.

[0068] Specifically, in step B2, the signal energy within the window corresponding to each time moment is used to... Normalization: The filtered complex signal is processed using a point-by-point sliding window method. By processing the current signal point by point throughout the fault time, the energy can be normalized, thereby suppressing the amplitude fluctuation caused by the sudden change of the fault DC component at the fault time, and thus eliminating the attenuation DC component and eliminating the influence of non-periodic components.

[0069] Furthermore, in step S3, the amplitude and phase of the three-phase power frequency phasors are calculated from the normalized complex signal using a complex analytical method, including the following steps C1-C2: C1. The normalized complex signal is modeled as a complex number containing time-varying amplitude and time-varying phase.

[0070] C2. Extract the power frequency phasor from the normalized complex signal using complex analytical methods to obtain the amplitude and phase.

[0071] Specifically, the phasor representation can be directly calculated using complex number analysis as follows: in, Let A be the power frequency phasor of the phase current. For the power frequency phasor of phase B current, For the power frequency phasor of the C-phase current, The signal is the complex signal after phase A is normalized. This is the complex signal after phase B normalization. The signal is the C-phase normalized complex signal. To take the real part of the complex number, To take the imaginary part of the complex number.

[0072] Furthermore, in step S4, sequence component conversion calculations are performed based on the three-phase power frequency phasors to obtain the positive sequence component, negative sequence component, and zero sequence component, thereby realizing the extraction of fault current power frequency parameters, including the following steps D1-D3: D1. Using the symmetrical component method, calculate the positive sequence component based on the three-phase power frequency phasors and the preset transformation coefficients.

[0073] D2. Calculate the negative sequence component based on the three-phase power frequency phasors and the preset transformation coefficients.

[0074] D3. Calculate the zero-sequence component based on the three-phase power frequency phasors and the preset transformation coefficients.

[0075] Specifically, the sequence component conversion and verification are performed based on the sequence component calculation using the three-phase power frequency phasors, as follows: in, It is the zero-sequence current component. This is the positive sequence current component. It is a negative sequence current component. The transformation coefficient represents a phase rotation of 120 degrees.

[0076] By comparing the required component calculation results obtained from electromagnetic transient simulation based on this invention with the calculation results from the tuning software, the short-circuit calculation results of the tuning software based on electromagnetic transient simulation can be verified. A typical example of the main wiring diagram for tuning calculation modeling is shown below. Figure 2 and Figure 3 As shown, the calculation results are compared with those in Tables 3, 4, 5 and 6.

[0077] Table 3 Comparison of Calculation Results with Table 1

[0078] Table 4 Comparison of Calculation Results with Table 2

[0079] Table 5 Comparison of Calculation Results with Table 3

[0080] Table 6 Comparison of Calculation Results with Table 4

[0081] Example 3 is an embodiment of the present invention. This embodiment provides a short-circuit current setting calculation simulation verification system based on Gaussian filtering, including a frequency shift filtering module, an energy normalization module, a phasor calculation module, and a sequence component conversion module.

[0082] The frequency shift filter module is used to collect the three-phase current signal at the fault point, perform frequency shift filtering on the three-phase current signal, and obtain the filtered complex signal.

[0083] The energy normalization module is used to extract the power frequency parameters of the fault current using the power frequency phasor estimation method, and to perform energy normalization processing on the filtered complex signal to obtain the normalized complex signal.

[0084] The phasor calculation module is used to calculate the amplitude and phase of three-phase power frequency phasors from the normalized complex signal using complex number analysis methods.

[0085] The sequence component conversion module is used to perform sequence component conversion calculations based on the three-phase power frequency phasors to obtain positive sequence components, negative sequence components, and zero sequence components, thereby realizing the extraction of power frequency parameters of fault current.

[0086] This embodiment also provides an electronic device applicable to a Gaussian-based short-circuit current setting calculation simulation verification method, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the Gaussian-based short-circuit current setting calculation simulation verification method proposed in the above embodiment.

[0087] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements a short-circuit current setting calculation, simulation, and verification method based on Gaussian filtering as proposed in the above embodiment.

[0088] The storage medium proposed in this embodiment and the method for calculating and verifying short-circuit current setting based on Gaussian filtering proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0089] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0090] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering, characterized in that: include, The three-phase current signal at the fault point is collected, and the three-phase current signal is subjected to frequency shift filtering to obtain the filtered complex signal. The power frequency parameters of the fault current are extracted by the power frequency phasor estimation method, and the energy normalization process is performed on the filtered complex signal to obtain the normalized complex signal. The amplitude and phase of the three-phase power frequency phasors are calculated from the normalized complex signal using complex analytical methods. Sequence component conversion calculations are performed based on the three-phase power frequency phasors to obtain positive sequence components, negative sequence components, and zero sequence components, thereby realizing the extraction of power frequency parameters of fault current.

2. The method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering as described in claim 1, characterized in that: The three-phase current signal at the fault point is collected, and the three-phase current signal is subjected to frequency shift filtering to obtain a filtered complex signal, including... Perform a quadrature frequency shift operation on each phase current signal to convert the power frequency component into a zero frequency component, and obtain the frequency-shifted three-phase current signal; Design a Gaussian low-pass filter and determine the cutoff frequency based on the power frequency and stopband attenuation. A finite impulse response Gaussian filter is designed using the window function method. Convolution operation is performed on the frequency-shifted three-phase current signal to obtain the filtered complex signal.

3. The method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering as described in claim 2, characterized in that: The fault current power frequency parameters are extracted using the power frequency phasor estimation method, and the filtered complex signal is then subjected to energy normalization processing to obtain the normalized complex signal. include, Select a window of preset time length, and use a point-by-point sliding window method to calculate the signal energy within the window at each moment of the filtered complex signal, starting from the signal start time. The filtered complex signal is normalized based on the signal energy within the window corresponding to each time moment, resulting in a normalized complex signal.

4. The method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering as described in claim 3, characterized in that: The calculation of the amplitude and phase of the three-phase power frequency phasors from the normalized complex signal using complex analytical methods includes, The normalized complex signal is modeled as a complex number containing time-varying amplitude and time-varying phase; The power frequency phasor is extracted from the normalized complex signal using complex analytical methods to obtain the amplitude and phase.

5. The method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering as described in claim 4, characterized in that: The design of the Gaussian low-pass filter, which determines the cutoff frequency based on the power frequency and stopband attenuation, includes: The cutoff frequency ensures that the signal attenuation of the Gaussian low-pass filter at the power frequency is below a preset threshold. The cutoff frequency ensures that the error tolerance of the Gaussian low-pass filter within the preset frequency offset range of the passband is lower than a preset value.

6. The method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering as described in claim 5, characterized in that: The selected window of preset time length uses a point-by-point sliding window method to calculate the signal energy within the window at each moment of the filtered complex signal, starting from the signal's initial time. include, Select a window of a preset time length and slide the window point by point starting from the signal start time; The filtered complex signal is processed within each window to obtain the signal energy within the window at each time step. The filtered complex signal is normalized based on the signal energy within the window corresponding to each time moment.

7. The method for calculating, simulating, and verifying short-circuit current setting based on Gaussian filtering as described in claim 6, characterized in that: The process involves performing sequence component conversion calculations based on three-phase power frequency phasors to obtain positive-sequence, negative-sequence, and zero-sequence components, thereby extracting power frequency parameters of the fault current. The positive sequence component is calculated using the symmetrical component method based on the three-phase power frequency phasors and preset transformation coefficients. The negative sequence component is calculated based on the three-phase power frequency phasors and the preset transformation coefficients; The zero-sequence component is calculated based on the three-phase power frequency phasors and preset transformation coefficients.

8. A short-circuit current setting calculation simulation verification system based on Gaussian filtering, using the short-circuit current setting calculation simulation verification method based on Gaussian filtering as described in any one of claims 1 to 7, characterized in that, include: Frequency shift filtering module, energy normalization module, phasor calculation module and sequence component conversion module; The frequency shift filtering module is used to collect the three-phase current signal at the fault point, perform frequency shift filtering on the three-phase current signal, and obtain the filtered complex signal. The energy normalization module is used to extract the fault current power frequency parameters by power frequency phasor estimation method, and to perform energy normalization processing on the filtered complex signal to obtain the normalized complex signal. The phasor calculation module is used to calculate the amplitude and phase of the three-phase power frequency phasors from the normalized complex signal using complex number analysis methods. The sequence component conversion module is used to perform sequence component conversion calculations based on the three-phase power frequency phasors to obtain positive sequence components, negative sequence components, and zero sequence components, thereby realizing the extraction of power frequency parameters of fault current.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the short-circuit current setting calculation simulation verification method based on Gaussian filtering as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the short-circuit current setting calculation simulation verification method based on Gaussian filtering as described in any one of claims 1 to 7.

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