Method and apparatus for determining current amplitude of cable, and processor

Abstract

Disclosed in the present invention are a method and apparatus for determining the current amplitude of a cable, and a processor. The method comprises: acquiring a target current waveform of a cable within a certain duration (S101); correcting an initial current frequency of the cable on the basis of a phase difference between current waveforms of the cable within two adjacent periods in the target current waveform, so as to obtain a target current frequency of the cable (S102); determining a first number for complete-period sampling points on the basis of the target current frequency and a sampling frequency (S103), wherein the sampling frequency is used for indicating a time interval for collecting a current value on the target current waveform; selecting a second number of sampling points from the target current waveform on the basis of a first number of complete-period sampling points and the sampling frequency (S104), wherein there is a multiple relationship between the first number and the second number, and the second number is greater than the first number; and determining the current amplitude of the cable on the basis of current values corresponding to the second number of sampling points (S105).

Description

Method, device and processor for determining current amplitude of cable

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 24, 2023, with application number 202311589362.4, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power engineering technology, for example, a method, device and processor for determining the current amplitude of a cable. Background Art

[0003] When calculating the power-frequency current amplitude of a cable, the impact of the complex harmonic components contained in the cable current on the cable current amplitude is generally not considered. This approach is suitable for scenarios where the accuracy of the cable current amplitude is not critical. However, in some special scenarios, such as the calculation of cable primary insulation parameters, the accuracy of the cable current amplitude directly affects the accuracy of the cable's primary insulation parameters, which in turn affects the cable's safe operation and performance. Therefore, there is a technical problem of low accuracy in calculating the power-frequency current amplitude of the cable. Summary of the Invention

[0004] The present application provides a method, device, and processor for determining the current amplitude of a cable with high precision, so as to at least solve the technical problem of low calculation accuracy of the current amplitude of the cable.

[0005] The embodiment of the present application provides a method for determining the current amplitude of a cable. The method may include: obtaining a target current waveform of the cable within a certain time period; based on the phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform, correcting the initial current frequency of the cable to obtain the target current frequency of the cable, wherein the phase difference is used to indicate the difference between the phases of the current waveforms in the two adjacent cycles; determining a first number of full-cycle sampling points based on the target current frequency and a sampling frequency, wherein the sampling frequency is used to indicate the time interval for collecting current values ​​on the target current waveform; based on the first number of full-cycle sampling points and the sampling frequency, selecting a second number of sampling points in the target current waveform, wherein there is a multiple relationship between the first number and the second number, and the second number is greater than the first number; and determining the current amplitude of the cable based on the current values ​​corresponding to the second number of sampling points.

[0006] The present application also provides a device for determining the current amplitude of a cable. The device may include: an acquisition unit configured to acquire a target current waveform of the cable within a certain time period; a correction unit configured to correct the initial current frequency of the cable based on a phase difference between the current waveforms of the cable in two adjacent cycles of the target current waveform to obtain the target current frequency of the cable, wherein the phase difference indicates the difference between the phases of the current waveforms in the two adjacent cycles; a first determination unit configured to determine a first number of full-cycle sampling points based on the target current frequency and a sampling frequency, wherein the sampling frequency indicates the time interval for collecting current values ​​on the target current waveform; a selection unit configured to select a second number of sampling points from the target current waveform based on the first number of full-cycle sampling points and the sampling frequency, wherein the first number and the second number are in a multiple relationship and the second number is greater than the first number; and a second determination unit configured to determine the current amplitude of the cable based on the current values ​​corresponding to the second number of sampling points.

[0007] An embodiment of the present application further provides a computer-readable storage medium, which includes a stored program, wherein when the program is executed by a processor, the device where the computer-readable storage medium is located is controlled to execute any one of the methods in the embodiments of the present application.

[0008] The present embodiment further provides a processor configured to run a program, wherein the program, when run, executes any one of the methods in the present embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a flow chart of a method for determining a current amplitude of a cable according to an embodiment of the present application;

[0010] FIG2 is a flow chart of another method for determining the current amplitude of a cable according to an embodiment of the present application;

[0011] FIG3 is a schematic diagram of a device for determining the current amplitude of a cable according to an embodiment of the present application. DETAILED DESCRIPTION

[0012] The following will describe the technical solutions in the embodiments of this application in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0013] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0014] Example 1

[0015] According to an embodiment of the present application, an embodiment of a method for determining the current amplitude of a cable is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0016] FIG1 is a flow chart of a method for determining a current amplitude of a cable according to an embodiment of the present application. As shown in FIG1 , the method may include the following steps:

[0017] Step S101: obtaining a target current waveform of the cable within a certain period of time.

[0018] In the technical solution provided in step S101 above, a target current waveform of the cable can be acquired over a certain period of time using a waveform acquisition device. The waveform acquisition device can be an analog-to-digital converter or an oscilloscope, and is not limited here. The certain period of time can be preset. For example, the target period of time can be 45 ms, which is merely an example.

[0019] In this embodiment, the target current waveform of the cable within a certain time period includes waveforms corresponding to at least two adjacent periods.

[0020] Optionally, an analog-to-digital converter can be used to determine current data corresponding to each point on the target current waveform, where the cable current data can be circulating current data of the cable. For example, the cable circulating current data can be acquired using a 16-bit analog-to-digital converter. This is merely an example and does not limit the method for acquiring cable current data.

[0021] Step S102 : Based on the phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform, the initial current frequency of the cable is corrected to obtain the target current frequency of the cable.

[0022] In the technical solution provided in the above-mentioned step S102 of the present application, after obtaining the target current waveform of the cable according to step S101, the current waveforms corresponding to two adjacent cycles can be obtained on the target current waveform, and the initial current frequency of the cable can be corrected according to the phase difference between the current waveforms corresponding to the two adjacent cycles to obtain the target current frequency.

[0023] In this embodiment, for the sake of convenience, the current waveforms corresponding to two adjacent cycles may be referred to as the first current waveform and the second current waveform, respectively, wherein the phase angle of the first current waveform and the phase angle of the second current waveform may be determined, and then based on the difference between the phase angle of the first current waveform and the phase angle of the second current waveform, the phase difference between the current waveforms corresponding to the two adjacent cycles may be determined, and the phase difference is used to indicate the time offset between the first current waveform and the second current waveform.

[0024] Optionally, after determining the phase difference between the current waveforms of the cable in two adjacent cycles, the test current frequency of the cable may be corrected according to the phase difference, thereby obtaining the target current frequency of the cable.

[0025] For example, the correction coefficient for correcting the initial current frequency of the cable can be determined by the following formula.

[0026] Among them, df can be used to represent the correction coefficient for correcting the initial current frequency. It can be used to indicate the phase difference between the current waveforms of the cable in two adjacent cycles, and f0 can be used to indicate the initial current frequency of the cable.

[0027] Optionally, after the correction coefficient is determined, the initial current frequency of the cable may be corrected using the correction coefficient to obtain a corrected target current frequency.

[0028] For example, the initial current frequency of the cable can be corrected using the following formula.

[0029] f=f0+df

[0030] Wherein, f can be used to represent the target current frequency of the cable, f0 can be used to represent the initial current frequency of the cable, and df can be used to represent the correction coefficient for correcting the initial current frequency.

[0031] In this embodiment, the phase difference between the current waveforms of the cable in two adjacent cycles and the initial current frequency of the cable can be used to determine a correction coefficient for correcting the initial current frequency of the cable, and then the correction coefficient is used to correct the initial current frequency of the initial cable to obtain the target current frequency of the cable, so as to improve the stability of the current frequency of the cable and avoid the influence of frequency disturbance on the subsequent calculation of the current amplitude of the cable.

[0032] Step S103 : determining a first number of sampling points in a full cycle based on the target current frequency and the sampling frequency.

[0033] In the technical solution provided in step S103 of the present application, after determining the target current frequency of the cable according to step S102, a first number of full-cycle sampling points, i.e., the number of full-cycle sampling points, can be determined based on the target current frequency and the sampling frequency. The sampling frequency indicates the time interval for sampling current values ​​on the target current waveform. The value of the sampling frequency can be preset. For example, the sampling frequency can be 10 kHz. This is merely an example and does not limit the value of the sampling frequency.

[0034] In this embodiment, after determining the target current frequency, the quotient of the target current frequency and the sampling frequency can be processed using a rounding function to determine the number of sampling points corresponding to a complete cycle, that is, the first number of sampling points in the entire cycle, and then sampling points are selected on the target current waveform based on the number of sampling points.

[0035] For example, the first number of sampling points may be determined by the following formula.

[0036] Where N can be used to represent the first number of sampling points, int is the rounding function, and F s It can be used to indicate the sampling frequency, f can be used to indicate the target current frequency of the cable, and 0.5 is a rounded-off predetermined value.

[0037] In this embodiment, the first number of full-cycle sampling points may be determined according to the target current frequency and the sampling frequency to provide a data reference for subsequent selection of sampling points from the target current waveform.

[0038] Step S104 : selecting a second number of sampling points in the target current waveform based on the first number of full-cycle sampling points and the sampling frequency.

[0039] In the technical solution provided in step S104 of the present application, after the first number of sampling points is calculated in step S103, a second number of sampling points to be selected from the target current waveform can be further determined based on the first number of sampling points in a full cycle and the sampling frequency. That is, the second number is used to indicate the number of sampling points to be selected from the target current waveform. The first number and the second number are in a multiple relationship, and the second number is greater than the first number. That is, the first number can be used to calculate the second number.

[0040] In this embodiment, after determining the first number, twice the first number can be determined as the second number of sampling points selected from the target current waveform. For example, assuming the first number is N, the second number of sampling points selected from the target current waveform can be 2N.

[0041] Step S105 : determining the current amplitude of the cable based on the current values ​​corresponding to the second number of sampling points.

[0042] In the technical solution provided in the above step S105 of the present application, after determining the second number of sampling points selected from the target current waveform according to the above step S104, the second number of sampling points can be selected sequentially from the target current waveform according to the sampling frequency, and the current amplitude of the cable can be determined based on the current values ​​corresponding to the second number of sampling points.

[0043] In this embodiment, after determining the second number of sampling points to be selected from the target current waveform, the second number of sampling points may be sequentially selected from the target current waveform based on the sampling frequency. For example, assuming the second number is 2N and the sampling frequency is 10 kHz, a sampling point may be selected from the target current waveform at intervals of 0.1 ms at the sampling frequency until 2N sampling points are selected.

[0044] Optionally, as can be seen from the introduction of the aforementioned step S101, the current data of each sampling point on the target current waveform can be obtained using an analog-to-digital converter. Based on this, after determining 2N sampling points from the target current waveform, the current data corresponding to each of the 2N sampling points can also be determined to form a current data set. For example, the current data set can be {i0, i1, i2, ..., i 2N-1}, this is just an illustrative example.

[0045] Optionally, after determining the current data sets corresponding to the current values ​​corresponding to the second number of sampling points, the first number of current sets may be determined based on the current data sets.

[0046] For example, a first number of current values ​​may be selected from the current data set in sequence as the starting points of the first number of current sets. 2N-1}Select i0, i1, i2, ...i N-1 As the starting point for the first number of period sets.

[0047] Optionally, after determining the starting points of the first number of cycle sets, the position corresponding to each starting point in the current data set can be used as the starting position, and a first number of current values ​​can be selected from the current data set in sequence as the current values ​​of the corresponding current cycle.

[0048] For example, the first number of current sets obtained can be represented as {i0, i1, i2, ..., i N-1}、{i1、i2、i3、......i N}、......{i N-1 、i N+1 、i N+2 、......i 2N-1}.

[0049] Optionally, after determining the first number of current sets, the current fundamental frequency effective value corresponding to each cycle may be calculated, wherein the calculated current fundamental frequency effective values ​​corresponding to the first number of current sets may be A0, A1, A2, ..., A N-1 Afterwards, the average value of the current fundamental frequency effective values ​​corresponding to the first number of current sets can be determined as the current amplitude of the cable, so that a relatively accurate cable current amplitude can be obtained.

[0050] In the above steps S101 to S105 of the present application, the initial current frequency of the cable is corrected by utilizing the phase difference between the current waveforms of the cable in two adjacent cycles. This can correct the disturbance of the current frequency of the cable caused by the complex harmonic components contained in the cable current. The number of sampling points of the entire cycle is determined based on the corrected current frequency and the sampling frequency, which can make the determined number of sampling points closer to the number of samples of the entire cycle. Then, according to the number of sampling points of the entire cycle and the sampling frequency, a second number of sampling points are selected from the target current waveform, and the current amplitude of the cable is determined according to the current values ​​of the selected sampling points. This can improve the accuracy of the current amplitude of the cable, achieve the technical effect of improving the calculation accuracy of the current amplitude of the cable, and thus solve the technical problem of low calculation accuracy of the current amplitude of the cable.

[0051] The above method of this embodiment is further introduced below.

[0052] As an optional embodiment, step S102 corrects the initial current frequency of the cable based on the phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform to obtain the target current frequency of the cable, including: determining a first phase angle of the current waveform in the first cycle, and determining a second phase angle of the current waveform in the second cycle, wherein the first cycle and the second cycle are two adjacent cycles; determining the difference between the first phase angle and the second phase angle as the phase difference; determining a correction coefficient of the initial current frequency based on the product of the phase difference and the initial current frequency; and correcting the initial current frequency based on the correction coefficient to obtain the target current frequency.

[0053] In this embodiment, the target current waveform includes current waveforms corresponding to at least two adjacent periods. Based on this, the current waveforms corresponding to two adjacent periods in the target current waveform can be obtained. For the convenience of explanation, the current waveforms corresponding to the two adjacent periods can be respectively referred to as the current waveform in the first period and the current waveform in the second period. The first phase angle of the current waveform in the first period and the second phase angle of the current waveform in the second period can be respectively determined.

[0054] Optionally, after determining the first phase angle of the current waveform in the first cycle and the second phase angle of the current waveform in the second cycle, the difference between the first phase angle and the second phase angle can be determined as the phase difference between the current waveforms in two adjacent cycles.

[0055] For example, the phase difference between the current waveforms in two adjacent cycles can be determined by the following formula.

[0056] in, It can be used to express the phase difference between the current waveforms in two adjacent cycles. It can be used to represent the first phase angle of the current waveform in the first cycle. It can be used to represent the second phase angle of the current waveform in the second period.

[0057] Optionally, after determining the phase difference between the current waveforms in two adjacent cycles, the product of the phase difference and the initial current frequency of the cable may be determined by the following formula to determine a correction coefficient for the initial current frequency of the cable.

[0058] Among them, df can be used to represent the correction coefficient for correcting the initial current frequency. It can be used to indicate the phase difference between the current waveforms of the cable in two adjacent cycles, and f0 can be used to indicate the initial current frequency of the cable.

[0059] Optionally, after the correction coefficient is determined, the initial current frequency may be corrected based on the correction coefficient to obtain the target current frequency.

[0060] As an optional embodiment, the initial current frequency is corrected based on the correction coefficient to obtain the target current frequency, including: determining the sum of the correction coefficient and the initial current frequency as the target current frequency.

[0061] In this embodiment, after the correction coefficient for correcting the initial current frequency of the cable is determined, the sum of the correction coefficient and the initial current frequency may be determined as the target current frequency.

[0062] For example, the target current frequency of the cable can be determined by the following formula.

[0063] f=f0+df

[0064] Wherein, f can be used to represent the target current frequency of the cable, f0 can be used to represent the initial current frequency of the cable, and df can be used to represent the correction coefficient for correcting the initial current frequency.

[0065] As an optional embodiment, step S103 determines the first number of sampling points in the entire cycle based on the target current frequency and the sampling frequency, including: determining the quotient between the sampling frequency and the target current frequency; and rounding the sum of the quotient and a predetermined value to obtain the first number of sampling points in the entire cycle.

[0066] In this embodiment, the sampling frequency is used to indicate the time interval for collecting current values ​​on the target current waveform. The target current frequency is the current frequency of the cable obtained by correcting the initial current frequency of the cable. Based on this, after determining the target current frequency and the sampling frequency, the quotient between the sampling frequency and the target current frequency can be determined, and then the sum of the quotient and the predetermined value can be rounded using a rounding function to obtain the first number of sampling points in the entire cycle.

[0067] For example, the first number of sampling points in a full cycle may be determined by the following formula.

[0068] Where N can be used to represent the first number of sampling points in the entire cycle, int is the rounding function, and F s It can be used to indicate the sampling frequency, and f can be used to indicate the target current frequency of the cable. Used to represent the quotient between the sampling frequency and the target current frequency, with 0.5 being a rounded-off value.

[0069] As an optional embodiment, step S104, based on the first number of full-cycle sampling points and the sampling frequency, selects a second number of sampling points in the target current waveform, including: selecting the second number of sampling points at intervals of the sampling frequency in the target current waveform, wherein the second number of sampling points are arranged in order of sampling time.

[0070] In this embodiment, after determining the first number, a second number of sampling points selected from the target current waveform may be determined based on the first number, wherein the second number of sampling points selected from the target current waveform may be determined based on a multiple of the first number.

[0071] For example, assuming the first number is N, 2N can be used as the second number of sampling points selected from the target current waveform. Subsequently, a second number of sampling points can be selected from the target current waveform at intervals of the sampling frequency, where the second number of sampling points are arranged in sampling time order. The sampling frequency can be 10 kHz, meaning that a sampling point can be selected from the target current waveform every 0.1 ms.

[0072] As an optional embodiment, step S105 determines the current amplitude of the cable based on the current values ​​corresponding to the second number of sampling points, including: determining the current values ​​corresponding to the second number of sampling points on the target current waveform based on the second number of sampling points; generating a first number of current sets based on the current values ​​corresponding to the second number of sampling points, wherein each current set includes the first number of current values; calculating the current amplitudes corresponding to the first number of current sets respectively; determining the average current amplitude corresponding to the first number of current sets based on the current amplitudes and the first number; and determining the average current amplitude as the current amplitude of the cable.

[0073] In this embodiment, after determining the second number of sampling points, since each sampling point corresponds to a current value, the current value corresponding to each sampling point in the second number of sampling points can be determined. Subsequently, based on the current values ​​corresponding to the second number of sampling points, a first number of current sets are generated. Each current set includes the first number of current values, that is, each current cycle includes the current values ​​corresponding to the first number of sampling points.

[0074] For example, as can be seen from the above description, the second number can be twice the first number. Based on this, assuming that the first number is 10, the second number can be 20. After determining the current values ​​corresponding to the 20 sampling points, 10 current sets can be generated based on the current values ​​corresponding to the 20 sampling points, where each current set can contain 10 current values. For example, among the current values ​​corresponding to the 20 sampling points, the first current value to the 10th current value can be formed as a current set, the second current value to the 11th current value can be formed as a current set, the third current value to the 12th current value can be formed as a current set, ..., the 10th current value to the 20th current value can be formed as a current set, to obtain 10 current sets.

[0075] Optionally, after obtaining the first number of current sets, the current amplitude corresponding to each current set may be determined, and then the average value of the current amplitudes corresponding to the first number of current sets may be determined as the current amplitude of the cable.

[0076] For example, the current amplitude corresponding to each current set can be determined by the following formula.

[0077] Among them, A j can be used to represent the current amplitude corresponding to the jth current set, N can be used to represent the first quantity, that is, the quantity corresponding to the current set, r j Can be used to represent real parameters, v j Can be used to represent imaginary parameters. j can be from 0 to N-1.

[0078] Optionally, after determining the current amplitude corresponding to each current set in the first number of current sets, the average current amplitude of the current amplitudes corresponding to the first number of current sets may be determined by the following formula.

[0079] Wherein, I can be used to represent the average current amplitude of the current amplitudes corresponding to the first number of current sets, N can be used to represent the first number, A i It can be used to represent the current amplitude corresponding to the j-th current set.

[0080] As an optional embodiment, generating a first number of current sets based on current values ​​corresponding to the second number of sampling points includes: selecting a first number of current values ​​from the current values ​​corresponding to the second number of sampling points in the order of the second number of sampling points; using the first number of current values ​​as initial points of the first number of current sets; using the positions of the initial points of the first number of current sets in the current values ​​corresponding to the second number of sampling points as starting positions, and selecting the first number of current values ​​from the current values ​​corresponding to the second number of sampling points in order for each starting position to obtain the first number of current sets.

[0081] In this embodiment, the order of the second number of sampling points can be used to represent the order of selecting the sampling points from the target current waveform. The first number of current values ​​can be selected from the current values ​​corresponding to the second number of sampling points according to the order of the second number of sampling points, wherein the order of the second number of sampling points is consistent with the order of the current values ​​corresponding to the second number of sampling points.

[0082] For example, assuming that the second number is 20, the first 10 current values ​​among the current values ​​corresponding to the 20 sampling points may be determined as the first number of current values ​​selected from the current values ​​corresponding to the second number of sampling points.

[0083] Optionally, after selecting the first number of current values ​​from the current values ​​corresponding to the second number of sampling points, the positions of the selected first number of current values ​​in the current values ​​corresponding to the second number of sampling points can be used as starting positions, and the first number of current values ​​can be selected in sequence for each starting position to form a first number of current sets.

[0084] For example, the 10 current values ​​selected above can be used as the starting points of 10 current sets. Then, 10 current values ​​are selected in sequence with the positions of the 10 current values ​​in the 20 current values ​​as the starting positions to form 10 current sets. The resulting 10 current sets can be expressed as {i0, i1, i2, ..., i 11}、{i1、i2、i2、......i 10}、......{i9、i 10 、i 11 、......i 19}.

[0085] In the above steps, the initial current frequency of the cable is corrected by utilizing the phase difference between the current waveforms of the cable in two adjacent cycles. This can correct the disturbance of the current frequency of the cable caused by the complex harmonic components contained in the cable current. The number of sampling points of the entire cycle is determined based on the corrected current frequency and the sampling frequency. This can make the determined number of sampling points closer to the number of samples of the entire cycle. Then, based on the number of sampling points of the entire cycle and the sampling frequency, a second number of sampling points are selected from the target current waveform, and the current amplitude of the cable is determined based on the current values ​​of the selected sampling points. This can improve the accuracy of the current amplitude of the cable, achieve the technical effect of improving the calculation accuracy of the current amplitude of the cable, and thus solve the technical problem of low calculation accuracy of the current amplitude of the cable.

[0086] Example 2

[0087] The technical solution of the embodiment of the present application is illustrated below in combination with optional implementation methods.

[0088] When calculating cable current amplitude, the impact of complex harmonic components contained in the cable current on the cable current frequency is generally not considered. This approach is suitable for scenarios where the accuracy of the cable current amplitude is not critical. However, in some special scenarios, such as the calculation of cable primary insulation parameters, the accuracy of the cable current amplitude directly affects the accuracy of the cable's primary insulation parameters, which in turn affects the cable's safe operation and performance. Therefore, there is a technical problem of low cable current amplitude calculation accuracy.

[0089] However, an embodiment of the present application provides a method for determining the current amplitude of a cable, obtaining a target current waveform of the cable within a certain period of time; based on the phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform, correcting the initial current frequency of the cable to obtain the target current frequency of the cable, wherein the phase difference is used to indicate the difference between the phases of the current waveforms in two adjacent cycles; based on the target current frequency and the sampling frequency, determining a first number of full-cycle sampling points, wherein the sampling frequency is used to indicate the time interval for collecting current values ​​on the target current waveform; based on the first number of full-cycle sampling points and the sampling frequency, selecting a second number of sampling points in the target current waveform, wherein there is a multiple relationship between the first number and the second number, and the second number is greater than the first number; and determining the current amplitude of the cable based on the current values ​​corresponding to the second number of sampling points. Since the phase difference between the current waveforms of the cable in two adjacent cycles is utilized to correct the initial current frequency of the cable, the disturbance of the current frequency of the cable caused by the complex harmonic components contained in the cable current can be corrected. The number of sampling points of the entire cycle is determined based on the corrected current frequency and the sampling frequency, which can make the determined number of sampling points closer to the number of samples in the entire cycle. Then, according to the number of sampling points of the entire cycle and the sampling frequency, a second number of sampling points are selected from the target current waveform, and the current amplitude of the cable is determined according to the current values ​​of the selected sampling points. This can improve the accuracy of the current amplitude of the cable, achieve the technical effect of improving the calculation accuracy of the current amplitude of the cable, and thus solve the technical problem of low calculation accuracy of the current amplitude of the cable.

[0090] Next, the calculation process of the current amplitude of the cable is introduced.

[0091] FIG2 is a flow chart of another method for determining the current amplitude of a cable according to an embodiment of the present application. The method may include the following steps:

[0092] Step S201: obtaining a phase difference between two adjacent cycles of a current waveform of a cable.

[0093] In this embodiment, the phase difference between the current waveforms corresponding to two adjacent periods in the current waveform of the cable may be determined using an angle difference method.

[0094] For example, the phase angle of a first cycle waveform and the phase angle of a second cycle waveform can be calculated separately, where the first cycle waveform and the second cycle waveform are two adjacent cycle waveforms. After determining the phase angle corresponding to the first cycle waveform and the phase angle corresponding to the second cycle, the phase difference corresponding to the two adjacent cycles can be determined using the following formula.

[0095] in, It can be used to express the phase difference between the current waveforms in two adjacent cycles. It can be used to represent the phase angle of the first cycle waveform. It can be used to represent the phase angle of the second cycle waveform.

[0096] Step S202: determining a correction coefficient for correcting the initial current frequency of the cable based on the phase difference.

[0097] In this embodiment, after the phase difference between two adjacent periodic waveforms is determined, a correction coefficient for correcting the initial current frequency of the cable can be determined by the following formula.

[0098] Among them, df can be used to represent the correction coefficient for correcting the initial current frequency. It can be used to indicate the phase difference between the current waveforms of the cable in two adjacent cycles, and f0 can be used to indicate the initial current frequency of the cable.

[0099] Step S203: Correct the initial current frequency of the cable based on the correction coefficient to obtain the target current frequency of the cable.

[0100] In this embodiment, after the correction coefficient for correcting the initial current frequency of the cable is determined, the initial current frequency of the cable can be corrected using the following formula.

[0101] f=f0+df

[0102] Wherein, f can be used to represent the target current frequency of the cable, f0 can be used to represent the initial current frequency of the cable, and df can be used to represent the correction coefficient for correcting the initial current frequency.

[0103] Step S204 : determining the number of sampling points in a full cycle based on the target current frequency of the cable.

[0104] In this embodiment, after the target current frequency of the cable is determined, the number of full-cycle sampling points in the current waveform of the cable can be determined by the following formula.

[0105] Among them, N can be used to represent the number of positive cycle sampling points, int is the rounding function, F s It can be used to indicate the sampling frequency, and f can be used to indicate the target current frequency of the cable. Used to represent the quotient between the sampling frequency and the target current frequency, with 0.5 being a rounded-off value.

[0106] Step S205 : selecting a plurality of current values ​​from the discrete current sequence based on the number of sampling points in the entire cycle.

[0107] In this embodiment, after the number of sampling points in a full cycle is determined, multiple current values ​​may be selected from the discrete current sequence, and the number of the selected current values ​​may be twice the number of sampling points in the full cycle.

[0108] For example, the discrete current sequence i={i0, i1, i2.....i k ......i M-1} select 2N-1 current values ​​{i0, i1, i2.....i 2N-1}, which is used to calculate the current amplitude of the cable.

[0109] Step S206: Calculate the current amplitude of the cable based on the multiple current values.

[0110] In this embodiment, current sequences having the same number as the number of sampling points in a full cycle may be generated based on multiple current values, and the current amplitude of the cable may be determined based on the average value of the current amplitudes corresponding to the multiple current sequences.

[0111] For example, the first current sequence can be i={i0, i1, i2.....i N-1}, take the i-th current sequence as i={i k ,i k+1 ,i k+2 .....i N+k-1}, where (k=1, 2, ...N-1), based on this, N current sequences can be obtained.

[0112] Optionally, after N current sequences are calculated, the current amplitude corresponding to each current sequence may be calculated using the following formula.

[0113] Real part

[0114] Imaginary part

[0115] Wherein, A(1) may be the current amplitude corresponding to the first current sequence, N is the number of current sequences, and k=0, 1, 2, 3, ... N-1.

[0116] Optionally, the current amplitudes corresponding to N current sequences can be calculated according to the above formula. Then, the current amplitudes corresponding to the N current sequences can be averaged using the following formula to obtain the current amplitude of the cable.

[0117] In an embodiment of the present application, the initial current frequency of the cable is corrected by utilizing the phase difference between the current waveforms of the cable in two adjacent cycles. This can correct the disturbance of the current frequency of the cable caused by the complex harmonic components contained in the cable current. The number of sampling points of the entire cycle is determined based on the corrected current frequency and the sampling frequency. This can make the determined number of sampling points closer to the number of samples of the entire cycle. Then, based on the number of sampling points of the entire cycle and the sampling frequency, a second number of sampling points are selected from the target current waveform, and based on the current values ​​of the selected sampling points, the current amplitude of the cable is determined. This can improve the accuracy of the current amplitude of the cable, achieve the technical effect of improving the calculation accuracy of the current amplitude of the cable, and thus solve the technical problem of low calculation accuracy of the current amplitude of the cable.

[0118] Example 3

[0119] According to an embodiment of the present application, a device for determining the current amplitude of a cable is further provided. It should be noted that the device for determining the current amplitude of a cable can be used to execute the method for determining the current amplitude of a cable in Example 1.

[0120] FIG3 is a schematic diagram of a device for determining the current amplitude of a cable according to an embodiment of the present application. As shown in FIG3 , the device 300 for determining the current amplitude of a cable may include: an acquisition unit 301 , a correction unit 302 , a first determination unit 303 , a selection unit 304 , and a second determination unit 305 .

[0121] The acquisition unit 301 is configured to acquire a target current waveform of the cable within a certain period of time.

[0122] The correction unit 302 is configured to correct the initial current frequency of the cable based on the phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform to obtain the target current frequency of the cable, wherein the phase difference is used to indicate the difference between the phases of the current waveforms in two adjacent cycles.

[0123] The first determining unit 303 is configured to determine a first number of sampling points in a whole cycle based on a target current frequency and a sampling frequency, wherein the sampling frequency is used to indicate a time interval for sampling current values ​​on a target current waveform.

[0124] The selection unit 304 is configured to select a second number of sampling points in the target current waveform based on the first number of full-cycle sampling points and the sampling frequency, wherein the first number and the second number are in a multiple relationship and the second number is greater than the first number.

[0125] The second determining unit 305 is configured to determine the current amplitude of the cable based on the current values ​​corresponding to the second number of sampling points.

[0126] Optionally, the correction unit 302 includes: a first determination module, configured to determine a first phase angle of the current waveform in a first cycle, and to determine a second phase angle of the current waveform in a second cycle, wherein the first cycle and the second cycle are two adjacent cycles; a second determination module, configured to determine the difference between the first phase angle and the second phase angle as a phase difference; a third determination module, configured to determine a correction coefficient of the initial current frequency based on the product of the phase difference and the initial current frequency; and a correction module, configured to correct the initial current frequency based on the correction coefficient to obtain a target current frequency.

[0127] Optionally, the correction module includes: a determination submodule, configured to determine the sum of the correction coefficient and the initial current frequency as the target current frequency.

[0128] Optionally, the first unit 303 includes: a determination module configured to determine a quotient between the sampling frequency and the target current frequency; and an operation module configured to perform a rounding operation on the sum of the quotient and a predetermined value to obtain a first number of sampling points in an entire cycle.

[0129] Optionally, the selection unit 304 includes: a selection module configured to select a second number of sampling points at intervals of the sampling frequency in the target current waveform, wherein the second number of sampling points are arranged in order of sampling time.

[0130] Optionally, the second determination unit 305 further includes: a fourth determination module, configured to determine the current values ​​corresponding to the second number of sampling points on the target current waveform based on the second number of sampling points; a generation module, configured to generate a first number of current sets based on the current values ​​corresponding to the second number of sampling points, wherein each current set includes the first number of current values; a calculation module, configured to respectively calculate the current amplitudes corresponding to the first number of current sets; and a fifth determination module, configured to determine the average current amplitude as the current amplitude of the cable.

[0131] Optionally, the generation module includes: a first selection submodule, configured to select a first number of current values ​​from the current values ​​corresponding to the second number of sampling points in the order of the second number of sampling points; a determination submodule, configured to use the first number of current values ​​as the initial points of the first number of current sets; and a second selection submodule, configured to use the positions of the initial points of the first number of current sets in the current values ​​corresponding to the second number of sampling points as the starting positions, and for each starting position, sequentially select the first number of current values ​​from the current values ​​corresponding to the second number of sampling points to obtain the first number of current sets.

[0132] In this embodiment, the initial current frequency of the cable is corrected by utilizing the phase difference between the current waveforms of the cable in two adjacent cycles. This can correct the disturbance of the current frequency of the cable caused by the complex harmonic components contained in the cable current. The number of sampling points in the entire cycle is determined based on the corrected current frequency and the sampling frequency. This can make the determined number of sampling points closer to the number of samples in the entire cycle. Then, based on the number of sampling points in the entire cycle and the sampling frequency, a second number of sampling points are selected from the target current waveform, and the current amplitude of the cable is determined based on the current values ​​of the selected sampling points. This can improve the accuracy of the current amplitude of the cable, achieve the technical effect of improving the calculation accuracy of the current amplitude of the cable, and thus solve the technical problem of low calculation accuracy of the current amplitude of the cable.

[0133] Example 4

[0134] According to an embodiment of the present application, a computer-readable storage medium is further provided, which includes a stored program, wherein the program executes the method for determining the current amplitude of the cable in Example 1.

[0135] Example 5

[0136] According to an embodiment of the present application, a processor is further provided, which is configured to run a program, wherein the method for determining the current amplitude of the cable in Example 1 is executed when the program is run.

[0137] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0138] In the above embodiments of the present application, the descriptions of the multiple embodiments have different focuses. For parts that are not described in detail in one embodiment, please refer to the relevant descriptions of other embodiments.

[0139] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0140] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected to achieve the purpose of the present embodiment according to actual needs.

[0141] In addition, multiple functional units in various embodiments of the present application may be integrated into one processing unit, or multiple units may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or software functional units.

[0142] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the relevant technology, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes multiple instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the multiple embodiment methods of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store program codes.

Claims

1. A method for determining the current amplitude of a cable, comprising: Obtain the target current waveform of the cable within a certain period of time; Based on the phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform, the initial current frequency of the cable is corrected to obtain the target current frequency of the cable, wherein the phase difference is used to indicate the difference between the phases of the current waveforms in the two adjacent cycles; Determine a first number of full-cycle sampling points based on the target current frequency and a sampling frequency, wherein the sampling frequency is used to indicate a time interval for sampling current values ​​on the target current waveform; Based on the first number of sampling points in a whole cycle and the sampling frequency, selecting a second number of sampling points in the target current waveform, wherein there is a multiple relationship between the first number and the second number, and the second number is greater than the first number; The current amplitude of the cable is determined based on the current values ​​respectively corresponding to the second number of sampling points.

2. The method according to claim 1, wherein: The method of correcting the initial current frequency of the cable based on the phase difference between the current waveforms of the cable in two adjacent cycles of the target current waveform to obtain the target current frequency of the cable includes: Determine a first phase angle of the current waveform in a first cycle, and determine a second phase angle of the current waveform in a second cycle, wherein the first cycle and the second cycle are the two adjacent cycles; determining a difference between the first phase angle and the second phase angle as the phase difference; determining a correction coefficient of the initial current frequency based on the product of the phase difference and the initial current frequency; The initial current frequency is corrected based on the correction coefficient to obtain the target current frequency.

3. The method according to claim 2, wherein: The correcting the initial current frequency based on the correction coefficient to obtain the target current frequency includes: The sum of the correction coefficient and the initial current frequency is determined as the target current frequency.

4. The method according to claim 1, wherein: The step of determining a first number of full-cycle sampling points based on the target current frequency and the sampling frequency includes: determining a quotient between the sampling frequency and the target current frequency; A rounding operation is performed on the sum of the quotient and a predetermined value to obtain the first number of sampling points in the integer period.

5. The method according to claim 1, wherein: The selecting a second number of sampling points in the target current waveform based on the first number of sampling points in a whole cycle and the sampling frequency comprises: The second number of sampling points are selected in the target current waveform at intervals of the sampling frequency, wherein the second number of sampling points are arranged in sampling time sequence.

6. The method according to claim 1, wherein: The determining the current amplitude of the cable based on the current values ​​respectively corresponding to the second number of sampling points includes: Based on the second number of sampling points, determining current values ​​respectively corresponding to the second number of sampling points on the target current waveform; Based on the current values ​​respectively corresponding to the second number of sampling points, generating a first number of current sets, wherein each of the current sets includes the first number of current values; respectively calculating the current amplitudes corresponding to the first number of the current sets; Determine, based on the current amplitude and the first number, an average current amplitude corresponding to the first number of the current sets; The average current amplitude is determined as the current amplitude of the cable.

7. The method according to claim 6, wherein: The generating a first number of current sets based on the current values ​​respectively corresponding to the second number of sampling points includes: selecting the first number of current values ​​from the current values ​​corresponding to the second number of sampling points in an order of the second number of sampling points; Using the first number of the current values ​​as initial points of the first number of the current sets respectively; The positions of the initial points of the first number of the current sets in the current values ​​corresponding to the second number of the sampling points are respectively taken as starting positions, and for each of the starting positions, the first number of the current values ​​are selected in sequence from the current values ​​corresponding to the second number of the sampling points to obtain the first number of the current sets.

8. A device for determining the current amplitude of a cable, comprising: An acquisition unit is configured to acquire a target current waveform of the cable within a certain period of time; a correction unit, configured to correct the initial current frequency of the cable based on a phase difference between the current waveforms of the cable in two adjacent cycles in the target current waveform to obtain a target current frequency of the cable, wherein the phase difference is used to indicate a difference between the phases of the current waveforms in the two adjacent cycles; A first determining unit is configured to determine a first number of full-cycle sampling points based on the target current frequency and a sampling frequency, wherein the sampling frequency is used to indicate a time interval for collecting current values ​​on the target current waveform; a selection unit configured to select a second number of sampling points in the target current waveform based on the first number of full-cycle sampling points and the sampling frequency, wherein there is a multiple relationship between the first number and the second number, and the second number is greater than the first number; The second determining unit is configured to determine the current amplitude of the cable based on the current values ​​respectively corresponding to the second number of sampling points.

9. A computer-readable storage medium comprising a stored program, wherein: When the program is running, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

10. A processor configured to run a program, wherein: When the program is executed by the processor, the method according to any one of claims 1 to 7 is performed.

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