Method, device and electronic device for obtaining step response parameters of DC current transformer

Abstract

The embodiment of the present invention discloses a method, device, and electronic device for obtaining step response parameters of a direct current transformer. The method includes: obtaining a transient step signal from the secondary side of a current transformer; inputting a step current signal from the primary side of the current transformer; processing the transient step signal using a wavelet modulus maximum algorithm to sequentially obtain multiple modulus maxima; dividing the multiple modulus maxima into a step low value interval and a step high value interval; obtaining a first time window of a step low value corresponding to the step low value interval; obtaining a second time window of a step high value corresponding to the step high value interval; filtering the transient step signal in each time window using a preset filtering method to obtain a transient step signal to be used in each time window; obtaining a step value based on the transient step signal to be used in each time window, the step value including a step low value and a step high value; and obtaining a step response parameter based on each step value.

Description

Technical Field

[0001] The present invention relates to the field of signal processing technology, and in particular to a method, device and electronic equipment for obtaining step response parameters of a direct current transformer. Background Art

[0002] After a fault or disturbance occurs in a DC transmission project, the correct operation of the DC control and protection system, the accurate fault location, and the reliability of the online insulation monitoring system are all crucial to its proper operation and monitoring. The measurement accuracy of DC current transformers is fundamental to ensuring the reliable operation of the DC control and protection system. Transient step characteristics are a key parameter that measures the DC current transformer's response and recovery to the original signal when electrical quantities in the DC transmission primary system change. Distortion in the transmission accuracy of transient step signals directly impacts the DC control and protection algorithm, resulting in inaccurate calculations of voltage and current parameters. This can cause the DC control and protection system to malfunction, significantly impacting the engineering implementation of DC transmission systems.

[0003] Currently, the determination of the step response parameters of a DC current transformer usually requires the participation of staff, such as manually determining the time window, which greatly affects the accuracy of the subsequently obtained step response parameters.

[0004] Therefore, a method for obtaining step response parameters is needed to solve the above technical problems. Summary of the Invention

[0005] The embodiments of the present invention provide a method, device and electronic device for obtaining step response parameters of a DC current transformer to solve the above technical problems.

[0006] In a first aspect, an embodiment of the present invention provides a method for obtaining step response parameters of a DC current transformer, the method comprising:

[0007] Acquire a transient step signal from the secondary side of a current transformer; input a step current signal from the primary side of the current transformer;

[0008] Processing the transient step signal by a wavelet modulus maximum algorithm to obtain a plurality of modulus maxima in sequence;

[0009] Divide multiple modulus maxima into step low value interval segments and step high value interval segments;

[0010] Obtaining a first time window of a step low value corresponding to the step low value interval;

[0011] Obtaining a second time window of step high values ​​corresponding to the step high value interval;

[0012] Filtering the transient step signal in each time window by a preset filtering method to obtain a transient step signal to be used in each time window, wherein the time windows include a first time window and a second time window;

[0013] Obtaining a step value based on the transient step signal to be used in each time window, wherein the step value includes a step low value and a step high value;

[0014] The step response parameters are obtained according to each step value.

[0015] In a second aspect, an embodiment of the present invention further provides a device for obtaining a step response parameter of a DC current transformer, the device comprising:

[0016] A transient step signal acquisition module is used to acquire a transient step signal from the secondary side of a current transformer; the primary side of the current transformer inputs a step current signal;

[0017] a modulus maximum acquisition module, configured to process the transient step signal using a wavelet modulus maximum algorithm to sequentially obtain a plurality of modulus maxima;

[0018] An interval segment acquisition module is used to divide multiple modulus maxima into step low value interval segments and step high value interval segments;

[0019] A first time window acquisition module is used to obtain a first time window of a step low value corresponding to the step low value interval;

[0020] A second time window acquisition module is used to obtain a second time window of the step high value corresponding to the step high value interval;

[0021] A filtering module, configured to filter the transient step signal in each time window by a preset filtering method to obtain a transient step signal to be used in each time window, wherein the time windows include a first time window and a second time window;

[0022] A step value acquisition module, configured to obtain a step value based on the transient step signal to be used in each time window, wherein the step value includes a step low value and a step high value;

[0023] The parameter acquisition module is used to obtain step response parameters according to each step value.

[0024] In a third aspect, an embodiment of the present invention further provides an electronic device, characterized in that the electronic device includes:

[0025] one or more processors;

[0026] a storage device for storing one or more programs,

[0027] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for obtaining step response parameters of a DC current transformer as described in any embodiment of the present invention.

[0028] In a fourth aspect, an embodiment of the present invention further provides a storage medium comprising computer-executable instructions, characterized in that the computer-executable instructions, when executed by a computer processor, are used to execute the method for obtaining the step response parameters of a DC current transformer as described in any embodiment of the present invention.

[0029] The technical solution of the embodiment of the present invention is to obtain the transient step signal of the current signal on the secondary side of the current transformer, process the transient step signal through the wavelet modulus maximum algorithm, obtain multiple modulus maxima in sequence, and divide the multiple modulus maxima into a step low value interval and a step high value interval. A first time window of the step low value corresponding to the step low value interval is obtained, and a second time window of the step high value corresponding to the step high value interval is obtained. The transient step signal in each time window is filtered by a pre-set filtering method to obtain a transient step signal to be used in each time window, wherein the time window includes a first time window and a second time window. Based on the transient step signal to be used in each time window, a step value is obtained, and the step value includes a step low value and a step high value. A step response parameter is obtained according to each step value. The technical solution of the embodiments of the present invention determines the time window by using the modulus maximum value, thereby improving the accuracy of the time window determination. A filtering method is then used to filter the transient step signal within the time window, thereby preventing interference from interfering signals and improving the accuracy of the transient step signal within the time window. Consequently, the transient step signal to be used within the time window is obtained more accurately. Thus, the step value obtained based on the transient step signal to be used within each time window, and the step response parameter derived from the step value, are also more accurately obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] in:

[0032] Figure 1 Schematic diagram of a flow chart of a method for obtaining step response parameters of a DC current transformer in an embodiment of the present invention;

[0033] Figure 2 Schematic diagram of mathematical morphology filtering in one embodiment;

[0034] Figure 3 FIG1 is a waveform diagram of filtering a transient step signal corresponding to a low step value by an alternating hybrid filter in one embodiment;

[0035] Figure 4a FIG. 1 is a schematic diagram showing that a step signal does not have overshoot oscillation during its rising process in an embodiment;

[0036] Figure 4b FIG1 is a schematic diagram showing overshoot oscillation in the rising process of a step signal in one embodiment;

[0037] Figure 5 Schematic diagram of the structure of a device for obtaining step response parameters of a DC current transformer in one embodiment;

[0038] Figure 6 FIG. 4 is a schematic structural diagram of an electronic device in an embodiment. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] In one embodiment, a method for obtaining step response parameters of a DC current transformer is provided. Figure 1 As shown, the method for obtaining the step response parameters of a DC current transformer according to the embodiment of the present invention is applicable to the case of obtaining the step response parameters of a DC current transformer. The method according to the embodiment of the present invention can be performed by a device for obtaining the step response parameters of a DC current transformer, which can be implemented in the form of software and / or hardware.

[0041] like Figure 1 As shown, the method for obtaining the step response parameters of a DC current transformer according to an embodiment of the present invention includes the following steps:

[0042] S110: Obtain a transient step signal on the secondary side of the current transformer.

[0043] Wherein, the primary side of the current transformer inputs a step current signal. It should be understood that the current transformer in the embodiment of the present invention is a DC current transformer.

[0044] Specifically, by inputting and outputting a step current signal on the primary side of the current transformer, a transient step current signal is output on the secondary side of the current transformer. Of course, the transient step signal waveform corresponding to the transient step current signal can also be obtained. Optionally, the transient step signal waveform can be recorded by a calibrator. When filtering, it is convenient for staff to check and observe the changes in the transient step signal waveform to determine whether the interference signal in the transient step signal has been removed.

[0045] S120 , processing the transient step signal by using a wavelet modulus maximum algorithm to sequentially obtain a plurality of modulus maxima.

[0046] In the embodiment of the present invention, a transient step signal is processed by a wavelet modulus maximum algorithm to obtain multiple modulus maxima, which prepares for the subsequent determination of a time window.

[0047] According to the wavelet transform theory and discrete wavelet principle, if there is a time point x n , in a certain neighborhood, if for all x, these two formulas:

[0048]

[0049] W 2j f(x)|≤|W 2j f(x n )|

[0050] Among them, point x n is the wavelet modulus maximum point at scale j, n is the sequence number of the time point, j is a constant, W 2j f(x n ) is the modulus maximum of the wavelet transform. W 2j f(x) represents the wavelet coefficient of f(x) at each scale 2j (j = 1, 2, ```, J). f(x) represents the original step signal. The modulus maximum point, sign, and amplitude essentially characterize the moment, direction, and instantaneous intensity of the signal's sudden change. Since the data before and after the applied step signal's sudden change in field testing reflects changes in physical characteristics or energy, extracting this moment using the modulus maximum can adaptively identify the moment of sudden change in the transient step signal, providing a basis for calculating the high and low step values.

[0051] S130: Divide the multiple modulus maxima into step low value interval segments and step high value interval segments.

[0052] The step low value refers to the initial steady-state value of the transient step signal, and the step high value refers to the final steady-state value of the transient step signal.

[0053] In the embodiment of the present invention, the step-low value interval and the step-high value interval are divided according to the multiple modulus maxima. This step prepares for the subsequent acquisition of the time window.

[0054] S140: Obtain a first time window of a step low value corresponding to the step low value interval.

[0055] Specifically, a first time window of a step low value corresponding to a step low value interval is obtained to prepare for subsequent acquisition of the step low value.

[0056] S150: Obtain a second time window of step high values ​​corresponding to the step high value interval.

[0057] Specifically, a first time window of a step high value corresponding to a step high value interval is obtained to prepare for subsequent acquisition of the step high value.

[0058] S160 : Filter the transient step signal in each time window using a preset filtering method to obtain a transient step signal to be used in each time window.

[0059] The time window includes a first time window and a second time window.

[0060] The transient step signal in each time window is filtered by a preset filtering method to obtain the transient step signal to be used in each time window. The embodiment of the present invention can filter the transient step signal by filtering to remove noise interference.

[0061] S170 : Obtain a step value based on the transient step signal to be used in each time window.

[0062] The step value includes a step low value and a step high value.

[0063] Specifically, the transient step signal to be used in each time window is processed to obtain a step value. The time window is determined by the method of an embodiment of the present invention to obtain the transient step signal within the time window, and the transient step signal within the time window is filtered to avoid noise interference from high-frequency signals and improve the accuracy of the step value.

[0064] S180. Obtain a step response parameter according to each step value.

[0065] In the embodiment of the present invention, a step response parameter is obtained through each step value, and the step response parameter can be obtained by processing the step value through a calculation formula corresponding to each step response parameter.

[0066] Optionally, obtaining a step response parameter according to each step value includes: obtaining a step amplitude and a moment corresponding to the step value according to the step value; obtaining a step response parameter by calculating the step amplitude and the moment, wherein the step response parameter includes at least one of a step rise moment, a peak moment, and an overshoot.

[0067] The method of the embodiment of the present invention obtains the step amplitude and the time corresponding to the step low value based on the step low value. Similarly, the step amplitude and the time corresponding to the step high value are obtained. In this way, the step response parameters can be calculated according to the calculation formula. Since the accuracy of the step value is improved, the accuracy of the step response parameters is also improved.

[0068] The technical solution of the embodiment of the present invention is to obtain the transient step signal of the current signal on the secondary side of the current transformer, process the transient step signal through the wavelet modulus maximum algorithm, obtain multiple modulus maxima in sequence, and divide the multiple modulus maxima into a step low value interval and a step high value interval. A first time window of the step low value corresponding to the step low value interval is obtained, and a second time window of the step high value corresponding to the step high value interval is obtained. The transient step signal in each time window is filtered by a pre-set filtering method to obtain a transient step signal to be used in each time window, wherein the time window includes a first time window and a second time window. Based on the transient step signal to be used in each time window, a step value is obtained, and the step value includes a step low value and a step high value. A step response parameter is obtained according to each step value. The technical solution of the embodiments of the present invention determines the time window by using the modulus maximum value, thereby improving the accuracy of the time window determination. A filtering method is then used to filter the transient step signal within the time window, thereby preventing interference from interfering signals and improving the accuracy of the transient step signal within the time window. Consequently, the transient step signal to be used within the time window is more accurate. Thus, the step value obtained based on the transient step signal to be used within each time window, and the step response parameter derived from the step value, are more accurate.

[0069] In another embodiment of the present invention, the filtering of the transient step signal in each time window by a preset filtering method to obtain the transient step signal to be used in each time window includes: filtering the transient step signal in each time window by a pre-constructed alternating hybrid filter to obtain the transient step signal to be used in each time window.

[0070] In this embodiment of the present invention, a pre-built alternating hybrid filter is used to filter the transient step signal within each time window. Because mathematical morphology filtering operates only in the signal's time domain, it eliminates the need for signal decomposition and reconstruction, thus avoiding errors caused by such decomposition and reconstruction. Furthermore, this filtering method is computationally convenient and easy to implement in engineering.

[0071] In the embodiment of the present invention, considering the influence of on-site electromagnetic interference and switching power supply noise, the step high value and the step low value are not DC signals and may be superimposed with high-frequency interference signals. Therefore, in the calculation process of the step high value and the step low value, filtering processing is performed. An alternating hybrid filter is constructed based on morphological opening and closing operations. The formula is:

[0072] [(f)altmix(g)](n)=[(f)OC(g)+(f)CO(g)](n) / 2,

[0073] Wherein, (f)OC(g) means that the step signal is first opened and then closed, and (f)CO(g) means that the step signal is first closed and then opened.

[0074] In order to verify the filtering effect of the alternating hybrid filter on the signal in the embodiment of the present invention, the following experiments were conducted:

[0075] Assume that the signal to be processed f(n) is the data in the time window selected after modulus maximum calibration, which is a one-dimensional multi-valued signal with a domain of D f ={0, 1, 2, ..., N}; g(n) is a one-dimensional structure element sequence whose domain is D g = {0, 1, 2, ..., P}; where P and N are integers, N ≥ P. Then the gray value expansion and erosion are defined as: (f⊕g)(n) = max{f(nx)+g(x)|(nx)∈D f And x∈D g}, (fΘg)(n)=min{f(n+x)-g(x)|(n+x)∈D f And x∈D g}.

[0076] Where: ⊕ represents the expansion operation, Θ represents the erosion operation, erosion followed by expansion is called the gray value opening operation, while expansion followed by erosion is called the gray value closing operation. n is the number of points in the one-dimensional structure element sequence, and x is the domain D. g The number in . Figure 2 As shown, Figure 2 (a) is the signal to be processed, and the opening operation process is Figure 2 (b), the opening operation can be used to filter out peak noise above the original signal, Figure 2 (c) shows the result of the open operation of the signal to be processed. The closed operation process is Figure 2 (d) is used to smooth or suppress the trough noise below the signal, Figure 2 (e) shows the result of the closed operation on the signal to be processed. It can be seen that both the open and closed operations perform low-pass filtering on the transient step signal in the time domain.

[0077] Figure 3 The waveform of the low-step signal obtained by performing noise interference filtering on the transient step signal corresponding to the low-step value using the alternating hybrid filter proposed in an embodiment of the present invention is shown.

[0078] In another embodiment of the present invention, the division of multiple modulus maxima into step low value interval segments and step high value interval segments includes: dividing the modulus maxima with positive values ​​into a first set; dividing the modulus maxima with negative values ​​into a second set; taking the moment corresponding to the largest modulus maximum in the first set as the first boundary value; taking the moment corresponding to the smallest modulus maximum in the second set as the second boundary value; taking the transient step within the initial moment and the first boundary value as the step low value interval segment; the initial moment is the moment corresponding to the sampling point of the first transient step signal; taking the transient step within the first boundary value and the second boundary value as the step high value interval segment.

[0079] In this embodiment of the present invention, some modulus maxima with positive modulus maxima are grouped into a first set, and some modulus maxima with negative modulus maxima are grouped into a second set. Then, the moment of the maximum value is selected from the first set as the first boundary value, and the minimum value is selected from the second set as the second boundary value. The transient step signal between the initial moment and the first boundary value is used as the low step value interval, and the transient step signal within the range of the first boundary value and the second boundary value is used as the high step value interval.

[0080] For example, the embodiment of the present invention first extracts the transient step signal recorded by the calibrator, that is, the transient step signal corresponding to the current signal obtained from the secondary side of the DC current transformer. The wavelet transform modulus maximum of the transient step signal is obtained to obtain the modulus maximum sequence: M = [M1 M2 M2…M n ]. M1 represents the first modulus maximum, M2 represents the second modulus maximum, M n Represents the nth modulus maximum.

[0081] The modulus maximum corresponds to the moment of sudden change of the step signal. Since the step signal applied on site is generally a square wave signal, the input signal of the DC current transformer in the embodiment of the present invention is a step signal, that is, a square wave signal. From the step rise to the continuous period and then to the step fall period, the largest energy change occurs in the step rise and step fall periods. Let M s The maximum value of the modulus of the transient step signal of the output current signal corresponding to the step rising stage is positive, and the corresponding time is s. x The maximum value of the modulus of the transient step signal of the output current signal corresponding to the step rising stage is negative, and the corresponding time is x, such as Figure 4a As shown, Figure 4aThe middle part shows that there is no overshoot oscillation during the rising process of the step signal. Figure 4b In the middle, there is overshoot oscillation in the rising stage of the step signal. Therefore, there are two modulus maxima in the rising stage and its oscillation process, namely M s With M s+1 , and the difference in size is large. The number of sampling points is n.

[0082] The modulus maxima of the transient step signal corresponding to the rising and falling phases of the step signal have opposite polarities. The absolute values ​​of the amplitudes are the largest and close to each other. Therefore, the detection criterion for the sudden change moment of the step signal is constructed as follows:

[0083] M s =max(M s1 M s2 M s3 …M sn ),

[0084] M x =min(M x1 M x2 M x3 …M xn ),

[0085]

[0086] Among them, k M is the ratio of the two modulus maxima. Since the two M s With M x is in the opposite direction, so k M Is a negative number. s1 Indicates the first modulus maximum in the sequence with a positive modulus maximum, corresponding to time s1, M sn Indicates the nth modulus maximum in the sequence with positive modulus maximum, and the corresponding time is sn. x1 Indicates the first modulus maximum in the sequence with a negative modulus maximum, corresponding to the moment x1. sn The nth modulus maximum in the sequence with a negative modulus maximum corresponds to time xn.

[0087] By k M It can also be used as a criterion to determine whether the selected largest modulus maximum and smallest modulus maximum are accurate. When the two modulus maxima do not meet the k M When judging, it means that there is an error between the two modulus maxima. These two modulus maxima are removed from their respective sequences, and the two sequences are updated, and the largest modulus maximum and the smallest modulus maximum are reselected.

[0088] The time t0 corresponding to the first sampling point in the transient step signal and the modulus maximum value M sThe data between the corresponding moments s is the step low value interval J1[t0, s], and the ... s Corresponding time s and M x The data at the time x corresponding to the modulus maximum is the step high value interval J2[s, x].

[0089] In another embodiment of the present invention, there are multiple sampling points in the step low value interval segment, and the sampling points have corresponding moments; the first time window of the step low value corresponding to the step low value interval segment is obtained, including: determining the center point from the multiple sampling points contained in the step low value interval segment, and obtaining the center moment of the center point, determining the preset time periods on both sides of the center moment, and determining the moment boundary values ​​on both sides of the first time window according to the preset time periods on both sides of the center moment, thereby obtaining the first time window.

[0090] In an embodiment of the present invention, a center point and a center moment of the center point are determined from a plurality of sampling points included in a step low value interval segment, and a preset time period on both sides of the center moment is determined. Based on the preset time period on both sides of the center moment, the moment boundary values ​​on both sides of the first time window are determined. For example, the center moment of the center point is t1, and both sides include 20 sampling points, the duration of the 20 sampling points is 4ms, and the first time window is T1 = [t1-4ms, t1+4ms].

[0091] In another embodiment of the present invention, before determining the center point and the center moment of the center point from the multiple sampling points included in the step low value interval segment, it also includes: if the number of sampling points in the step low value interval segment is an even number, removing the sampling point at the moment corresponding to the modulus maximum value.

[0092] In an embodiment of the present invention, when the number of sampling points in the step low value interval is an even number, the moment corresponding to the modulus maximum is determined, and the sampling point corresponding to the moment is removed, so that the number of sampling points in the step low value interval is an odd number, which facilitates the selection of the center point.

[0093] Similarly, obtaining a second time window corresponding to a step high value interval includes determining a center point from a plurality of sampling points included in the step high value interval, obtaining a center moment of the center point, determining a preset time period on either side of the center moment, and determining time boundary values ​​on either side of the second time window based on the preset time periods on either side of the center moment to obtain the second time window. Of course, if the number of sampling points included in the step high value interval is even, the sampling points at the moments corresponding to the modulus maximum are removed to obtain an odd number of sampling points to facilitate determination of the center point.

[0094] In another embodiment of the present invention, the step value is obtained based on the transient step signal to be used in each time window, including: obtaining a low step value by performing mean calculation on the transient step signal to be used in the first time window; and obtaining a high step value by performing mean calculation on the transient step signal to be used in the second time window.

[0095] In order to obtain the step low value, the embodiment of the present invention calculates the mean of the transient step signal to be used at each sampling point in the first time window to obtain the step low value. Similarly, the step high value is obtained.

[0096] In another embodiment of the present invention, if the standard step waveform is at t n The step amplitude at time u n , the corresponding step amplitude is n%. According to the interpolation calculation method, the corresponding step value and time between two discrete sampling points can be obtained:

[0097] u n =(J2-J1)×n%+J1

[0098]

[0099] Among them, J1 represents the step low value interval segment, and J2 represents the step high value interval segment.

[0100] Use interpolation to calculate the step amplitude u n The size of is related to the accuracy of calculating the high and low values ​​of the step.

[0101] For example, taking the calculation of the delay time T' as an example, the time difference between the standard step signal and the transient step signal of the DC current transformer reaching 10% of the difference between the final steady-state value (step high value) and the initial steady-state value (step low value) is defined as the delay time T'. The time and amplitude corresponding to the standard signal of 10% step amplitude (t 1-10％ ,u 1-10％ ), the corresponding previous discrete sampling point is (t 1-s1 ,u 1-s1 ), the next sampling point is (t 1-s2 ,u 1-s2 The moment and amplitude of the transient step signal of the DC current transformer with a 10% step amplitude are (t 2-10％ , v 2-10％ ), the corresponding previous discrete sampling point is (t 2-s1 , v 2-s1 ), the next sampling point is (t 2-s2 , v 2-s2 ).

[0102] The time corresponding to a 10% step amplitude can be calculated:

[0103]

[0104] T`=t 2-10％ -t 1-10％

[0105] T is the time corresponding to a 10% step amplitude.

[0106] Among them, t1 represents the time of the standard signal, t1-10% represents the time of the standard signal with a 10% step amplitude, u1 represents the amplitude corresponding to the standard signal with a 10% step amplitude, s1 represents a discrete sampling point, t 1-s1 Indicates the moment of the previous discrete sampling point of the standard signal with a 10% step amplitude, u 1-s1 The amplitude of the next discrete sampling point of the standard signal with a 10% step amplitude. 1-s2 Indicates the time of the next discrete sampling point of the standard signal with a 10% step amplitude, u 1-s2 The amplitude of the next discrete sampling point of the standard signal with a 10% step amplitude. t2 represents the instant of the transient step signal of the DC current transformer with a 10% step amplitude. f1 represents the sampling frequency of the standard signal (standard step signal), and f2 represents the sampling frequency of the DC current transformer step signal.

[0107] In another embodiment of the present invention, a device for obtaining step response parameters of a DC current transformer is provided. Figure 5 As shown, the device for obtaining step response parameters of a DC current transformer according to an embodiment of the present invention can execute the method for obtaining step response parameters of a DC current transformer provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. The device includes: a transient step signal acquisition module 610, a modulus maximum acquisition module 620, an interval acquisition module 630, a first time window acquisition module 640, a second time window acquisition module 650, a filtering module 660, a step value acquisition module 670, and a parameter acquisition module 680; wherein:

[0108] The transient step signal acquisition module 610 is used to acquire the transient step signal of the secondary side of the current transformer; the primary side input step current signal of the current transformer; the modulus maximum value acquisition module 620 is used to process the transient step signal by the wavelet modulus maximum value algorithm to obtain multiple modulus maxima in sequence; the interval acquisition module 630 is used to divide the multiple modulus maxima into step low value interval segments and step high value interval segments; the first time window acquisition module 640 is used to obtain the first time window of the step low value corresponding to the step low value interval segment; the second time window acquisition module 640 is used to obtain the first time window of the step low value corresponding to the step low value interval segment; the second time window acquisition module 640 is used to obtain the first time window of the step low value corresponding to the step low value interval segment. Module 650 is used to obtain a second time window of the step high value corresponding to the step high value interval; the filtering module 660 is used to filter the transient step signal in each time window by a preset filtering method to obtain the transient step signal to be used in each time window, and the time window includes a first time window and a second time window; the step value acquisition module 670 is used to obtain a step value based on the transient step signal to be used in each time window, and the step value includes a step low value and a step high value; the parameter acquisition module 680 is used to obtain a step response parameter according to each step value.

[0109] Furthermore, in this embodiment of the present invention, the interval acquisition module 630 is further configured to:

[0110] The modulus maxima with positive values ​​are divided into the first set; the modulus maxima with negative values ​​are divided into the second set; the moment corresponding to the largest modulus maximum in the first set is used as the first boundary value; the moment corresponding to the smallest modulus maximum in the second set is used as the second boundary value; the transient step within the initial moment and the first boundary value range is used as the step low value interval segment; the initial moment is the moment corresponding to the sampling point of the first transient step signal; the transient step within the first boundary value and the second boundary value range is used as the step high value interval segment.

[0111] Furthermore, in an embodiment of the present invention, there are multiple sampling points in the step low value interval, and the sampling points have corresponding moments; the first time window acquisition module 640 is further configured to:

[0112] Determine the center point from the multiple sampling points contained in the step low value interval segment, and obtain the center moment of the center point, determine the preset time periods on both sides of the center moment, and determine the moment boundary values ​​on both sides of the first time window based on the preset time periods on both sides of the center moment, thereby obtaining the first time window.

[0113] Furthermore, in an embodiment of the present invention, the apparatus further includes:

[0114] The sampling point removal module is used to remove the sampling point at the time corresponding to the modulus maximum value if the number of sampling points in the step low value interval is even.

[0115] Furthermore, in this embodiment of the present invention, the filtering module 660 is further configured to:

[0116] The transient step signal in each time window is filtered by a pre-built alternating hybrid filter to obtain a transient step signal to be used in each time window.

[0117] Furthermore, in this embodiment of the present invention, the step value acquisition module 670 is further configured to:

[0118] The low step value is obtained by performing mean calculation on the transient step signal to be used in the first time window; the high step value is obtained by performing mean calculation on the transient step signal to be used in the second time window.

[0119] Furthermore, in this embodiment of the present invention, the parameter acquisition module 680 is further configured to:

[0120] A step amplitude and a time corresponding to the step value are obtained according to the step value; and a step response parameter is obtained by calculating the step amplitude and the time, wherein the step response parameter includes at least one of a step rise time, a peak time, and an overshoot.

[0121] The technical solution of the embodiment of the present invention is to obtain the transient step signal of the current signal on the secondary side of the current transformer, process the transient step signal through the wavelet modulus maximum algorithm, obtain multiple modulus maxima in sequence, and divide the multiple modulus maxima into a step low value interval and a step high value interval. A first time window of the step low value corresponding to the step low value interval is obtained, and a second time window of the step high value corresponding to the step high value interval is obtained. The transient step signal in each time window is filtered by a pre-set filtering method to obtain a transient step signal to be used in each time window, wherein the time window includes a first time window and a second time window. Based on the transient step signal to be used in each time window, a step value is obtained, and the step value includes a step low value and a step high value. A step response parameter is obtained according to each step value. The technical solution of the embodiments of the present invention determines the time window by using the modulus maximum value, thereby improving the accuracy of the time window determination. A filtering method is then used to filter the transient step signal within the time window, thereby preventing interference from interfering signals and improving the accuracy of the transient step signal within the time window. Consequently, the transient step signal to be used within the time window is obtained more accurately. Thus, the step value obtained based on the transient step signal to be used within each time window, and the step response parameter derived from the step value, are also more accurately obtained.

[0122] It is worth noting that the various modules included in the above-mentioned device are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be realized; in addition, the specific names of the various functional modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the embodiments of the present invention.

[0123] In another embodiment of the present invention, an electronic device is provided. Figure 6 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. Figure 6 A block diagram of an exemplary electronic device 50 suitable for implementing exemplary embodiments of the present invention is shown. Figure 6 The electronic device 50 shown is only an example and should not limit the functionality and scope of use of the embodiments of the present invention.

[0124] like Figure 6 As shown, electronic device 50 is a general-purpose computing device. Components of electronic device 50 may include, but are not limited to, one or more processors or processing units 501, system memory 502, and a bus 503 connecting various system components (including system memory 502 and processing unit 501).

[0125] Bus 503 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures. Examples of these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0126] The electronic device 50 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device 50, including volatile and non-volatile media, removable and non-removable media.

[0127] System memory 502 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 504 and / or cache memory 505. Electronic device 50 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 506 may be used to read and write non-removable, non-volatile magnetic media ( Figure 6 Not shown, often called a "hard drive"). Although Figure 6Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 503 via one or more data medium interfaces. Memory 502 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of various embodiments of the present invention.

[0128] A program / utility 508 having a set (at least one) of program modules 507 may be stored, for example, in memory 502. Such program modules 507 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may include an implementation of a network environment. Program modules 507 generally implement the functions and / or methods of the embodiments described herein.

[0129] The electronic device 50 may also communicate with one or more external devices 509 (e.g., keyboard, pointing device, display 510, etc.), and may also communicate with one or more devices that enable a user to interact with the electronic device 50, and / or communicate with any device that enables the electronic device 50 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed through an input / output (I / O) interface 511. Furthermore, the electronic device 50 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 512. As shown, the network adapter 512 communicates with other modules of the electronic device 50 via the bus 503. It should be understood that although Figure 6 Not shown, other hardware and / or software modules may be used in conjunction with the electronic device 50, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0130] The processing unit 501 executes various functional applications and data processing by running the programs stored in the system memory 502 , for example, implementing the method for obtaining the step response parameters of a DC current transformer provided in an embodiment of the present invention.

[0131] In another embodiment of the present invention, a storage medium containing computer-executable instructions is further provided. When the computer-executable instructions are executed by a computer processor, they are used to perform a method for obtaining a step response parameter of a DC current transformer. The method includes:

[0132] Acquire a transient step signal on the secondary side of a current transformer; input a step current signal on the primary side of the current transformer; process the transient step signal by a wavelet modulus maximum algorithm to obtain a plurality of modulus maxima in sequence; divide the plurality of modulus maxima into a step low value interval and a step high value interval; obtain a first time window of a step low value corresponding to the step low value interval; obtain a second time window of a step high value corresponding to the step high value interval; filter the transient step signal in each time window by a preset filtering method to obtain a transient step signal to be used in each time window, the time window including a first time window and a second time window; obtain a step value based on the transient step signal to be used in each time window, the step value including a step low value and a step high value; obtain a step response parameter according to each step value.

[0133] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device.

[0134] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0135] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0136] The computer program code for performing the operations of the embodiments of the present invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0137] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for obtaining step response parameters of a DC current transformer, characterized in that: include: Obtaining a transient step signal on the secondary side of a current transformer; The primary side of the current transformer inputs a step current signal; Processing the transient step signal by a wavelet modulus maximum algorithm to obtain a plurality of modulus maxima in sequence; Divide multiple modulus maxima into step low value interval segments and step high value interval segments; Obtaining a first time window of a step low value corresponding to the step low value interval; Obtaining a second time window of step high values ​​corresponding to the step high value interval; Filtering the transient step signal in each time window by a preset filtering method to obtain a transient step signal to be used in each time window, wherein the time windows include a first time window and a second time window; Obtaining a step value based on the transient step signal to be used in each time window, wherein the step value includes a step low value and a step high value; Get step response parameters according to each step value; The step of dividing the multiple modulus maxima into step low value intervals and step high value intervals includes: Divide the modulus maxima whose values ​​are positive into the first set; Divide the modulus maxima whose values ​​are negative into the second set; The moment corresponding to the largest modulus maximum in the first set is taken as the first boundary value; The moment corresponding to the smallest modulus maximum in the second set is taken as the second boundary value; The transient step within the range of the initial moment and the first boundary value is regarded as the step low value interval; the initial moment is the moment corresponding to the sampling point of the first transient step signal; The transient step within the range of the first boundary value and the second boundary value is regarded as the step high value interval segment.

2. The method according to claim 1, characterized in that A plurality of sampling points in the step low value interval, each of the sampling points having a corresponding time; The obtaining of a first time window of a step low value corresponding to the step low value interval includes: Determine the center point from the multiple sampling points contained in the step low value interval segment, and obtain the center moment of the center point, determine the preset time periods on both sides of the center moment, and determine the moment boundary values ​​on both sides of the first time window based on the preset time periods on both sides of the center moment, thereby obtaining the first time window.

3. The method according to claim 2, characterized in that Before determining the center point from the plurality of sampling points included in the step low value interval and obtaining the center time of the center point, the method further includes: If the number of sampling points in the step low value interval is an even number, the sampling point at the time corresponding to the modulus maximum value is removed.

4. The method according to claim 1, wherein The filtering of the transient step signal in each time window by a preset filtering method to obtain the transient step signal to be used in each time window includes: The transient step signal in each time window is filtered by a pre-built alternating hybrid filter to obtain a transient step signal to be used in each time window.

5. The method according to claim 1, wherein The step value is obtained based on the transient step signal to be used in each time window, including: The step low value is obtained by performing mean calculation on the transient step signal to be used in the first time window; The step high value is obtained by performing mean calculation on the transient step signal to be used in the second time window.

6. The method according to claim 1, wherein The step response parameters are obtained according to each step value, including: Obtain the step amplitude and the time corresponding to the step value according to the step value; By calculating the step amplitude and time, a step response parameter is obtained, where the step response parameter includes at least one of a step rise time, a peak time, and an overshoot.

7. A device for obtaining step response parameters of a DC current transformer, characterized in that: include: A transient step signal acquisition module is used to acquire a transient step signal on the secondary side of the current transformer; The primary side of the current transformer inputs a step current signal; a modulus maximum acquisition module, configured to process the transient step signal using a wavelet modulus maximum algorithm to sequentially obtain a plurality of modulus maxima; An interval segment acquisition module is used to divide multiple modulus maxima into step low value interval segments and step high value interval segments; A first time window acquisition module is used to obtain a first time window of a step low value corresponding to the step low value interval; A second time window acquisition module is used to obtain a second time window of the step high value corresponding to the step high value interval; A filtering module, configured to filter the transient step signal in each time window by a preset filtering method to obtain a transient step signal to be used in each time window, wherein the time windows include a first time window and a second time window; A step value acquisition module, configured to obtain a step value based on the transient step signal to be used in each time window, wherein the step value includes a step low value and a step high value; The parameter acquisition module is used to obtain the step response parameters according to each step value. The interval segment acquisition module is specifically used to: Divide the modulus maxima whose values ​​are positive into the first set; Divide the modulus maxima whose values ​​are negative into the second set; The moment corresponding to the largest modulus maximum in the first set is taken as the first boundary value; The moment corresponding to the smallest modulus maximum in the second set is taken as the second boundary value; The transient step within the range of the initial moment and the first boundary value is regarded as the step low value interval; the initial moment is the moment corresponding to the sampling point of the first transient step signal; The transient step within the range of the first boundary value and the second boundary value is regarded as the step high value interval segment.

8. An electronic device, characterized in that: The electronic device comprises: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method for obtaining step response parameters of a DC current transformer as described in any one of claims 1 to 6.

9. A storage medium containing computer-executable instructions, characterized in that: When executed by a computer processor, the computer executable instructions are used to execute the method for obtaining step response parameters of a DC current transformer as claimed in any one of claims 1 to 6.

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