Method executed by differential relay protection device

Abstract

There is provided a method performed by a differential relay protection device, the method comprising: obtaining a first plurality of sample data having a first plurality of sample counts, where the first plurality of sample counts are associated with a first clock in the differential relay protection device; mapping the first plurality of sample data having the first plurality of sample counts into a second plurality of sample data having a second plurality of sample counts, the second plurality of sample counts being associated with a second clock in the differential relay protection device, and the first clock operating independently of the second clock; receiving a plurality of sample data having a second plurality of sample counts from one or more other differential relay protection devices; determining a differential current based on a second plurality of sample data and the plurality of sample data; and determining whether a circuit fault occurs based on the value of the differential current.

Description

Technical Field

[0001] This disclosure relates to a method performed by a differential relay protection device, and more particularly, to a method performed by the differential relay protection device when the differential relay protection device includes two independently operating clocks. Background Technology

[0002] Differential relay protection is based on Kirchhoff's current theorem (the sum of the currents flowing into a node in a circuit is equal to zero). It treats the protected electrical equipment (e.g., transformers, transmission lines, etc.) as a node. When the equipment is operating normally, the current flowing into and out of the equipment is equal, the differential current is zero, and the differential relay protection does not operate. However, when a fault occurs inside the equipment, the currents flowing into and out are no longer equal, the differential current is greater than zero, and when this current exceeds the setting value of the differential relay protection device, the protection operates, disconnecting the power supply to the faulty equipment.

[0003] One of the key technologies for implementing differential relay protection lies in synchronizing the current sampling values ​​at each end of electrical equipment, such as transmission lines. In some schemes, time synchronization of the substation can be achieved based on the Global Positioning System (GPS), thereby synchronizing the current sampling values. However, GPS-based current sampling value synchronization schemes have many uncertainties. For example, due to obstructions from buildings, terrain, and other obstacles, as well as weather factors, GPS signals may become very weak for periods of time. In such cases, the synchronization effect of GPS-based current sampling value synchronization schemes may deteriorate or fail.

[0004] Therefore, this disclosure proposes a method executed by a differential relay protection device in electrical equipment. For different differential relay protection devices in different electrical equipment, two independently operating clocks are set in each differential relay protection device. The first clock can be synchronized with or not synchronized with the master clock of the electrical equipment where the differential relay protection device is located. The second clock is a Precision Time Protocol (PTP) clock and is synchronized with the second clocks in other differential relay protection devices via PTP. By mapping the electrical quantities sampled by different differential relay protection devices in different electrical equipment under their respective first clock drives to electrical quantities based on the second clock, that is, time-aligned electrical quantities, the calculation of differential current is simplified, thereby simplifying the process of determining whether a circuit fault has occurred in relay protection. Summary of the Invention

[0005] According to one aspect of an embodiment of the present invention, a method performed by a differential relay protection device is provided, the method comprising: obtaining a first plurality of sample data having a first plurality of sample counts, wherein the first plurality of sample counts are associated with a first clock in the differential relay protection device; mapping the first plurality of sample data having the first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts, wherein the second plurality of sample counts are associated with a second clock in the differential relay protection device, and the first clock operates independently of the second clock; receiving a plurality of sample data having the second plurality of sample counts from one or more other differential relay protection devices; determining a differential current based on the second plurality of sample data and the plurality of sample data; and determining whether a circuit fault has occurred based on the value of the differential current.

[0006] In some examples, obtaining the first plurality of sample data with a first plurality of sample counts includes: sampling by a differential relay protection device based on a first sampling frequency under a first clock to obtain the first plurality of sample data; or receiving by the differential relay protection device the first plurality of sample data sampled by the merging unit under a first clock at a first sampling frequency from the merging unit, wherein the first sampling frequency is a predetermined sampling frequency.

[0007] In some examples, the sample data are electrical quantities.

[0008] In some examples, mapping a first plurality of sample data having a first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts includes: determining a ratio and a time difference between a second clock and a first clock; determining a second plurality of sample counts based on the first plurality of sample counts; and determining the second plurality of sample data having the second plurality of sample counts based on the ratio, the time difference, the first plurality of sample counts, the first plurality of sample data, and the second plurality of sample counts.

[0009] In some examples, determining the ratio and time difference between the second clock and the first clock includes, for every second elapsed by the first clock: determining the ratio between the length of time elapsed by the second clock and the length of time elapsed by the first clock as the ratio between the first clock and the second clock for that second; and determining the difference between the current time of the second clock and the current time of the first clock as the time difference between the first clock and the second clock for that second.

[0010] In some examples, determining a second plurality of sample counts based on a first plurality of sample counts includes: determining a maximum sample count and a minimum sample count among the first plurality of sample counts; for each of the maximum sample count and the minimum sample count, determining a specific maximum sample count and a specific minimum sample count corresponding to the maximum sample count and the minimum sample count, respectively, based on the ratio, the time difference, a first sampling frequency, and a second sampling frequency; and determining an integer between the specific maximum sample count and the specific minimum sample count as the second plurality of sample counts, wherein the second sampling frequency is a predetermined sampling frequency.

[0011] In some examples, determining a second plurality of sample data having a second plurality of sample counts based on the ratio, the time difference, the first plurality of sample counts, the first plurality of sample data, and the second plurality of sample counts includes, for each sample count in the second plurality of sample counts: determining a specific sample count corresponding to the sample count based on the ratio, the time difference, the first sampling frequency, and the second sampling frequency; determining specific sample data having the specific sample count based on the first plurality of sample counts, the first plurality of sample data, and the specific sample count; and determining the specific sample data as sample data having the sample counts.

[0012] In some examples, determining specific sample data having a specific sample count based on a first plurality of sample counts, a first plurality of sample data, and a specific sample count includes: determining, among the first plurality of sample counts, a sample count that is numerically closest to the specific sample count; and determining the sample data having said sample count as the specific sample data.

[0013] In some examples, determining specific sample data having a specific sample count based on a first plurality of sample counts, a first plurality of sample data, and a specific sample count includes: identifying two sample counts that are numerically adjacent to the specific sample count among the first plurality of sample counts; and interpolating based on two sample data having said two sample counts to determine the specific sample data.

[0014] In some examples, the second clock is a Precision Time Protocol (PTP) clock.

[0015] In some examples, determining whether a circuit fault has occurred based on the value of the differential current includes determining that a circuit fault has occurred when the value of the differential current is greater than a threshold.

[0016] In some examples, the method further includes: storing a second plurality of sample data having a second plurality of sample counts; and sending the second plurality of sample data having a second plurality of sample counts to the one or more other differential relay protection devices.

[0017] According to another aspect of the embodiments of the present invention, a differential relay protection device is provided, the differential relay protection device comprising: a clock module configured to create a first clock and a second clock, wherein the first clock and the second clock operate independently; a transceiver module; and a processing module configured to perform the aforementioned method.

[0018] According to another aspect of the embodiments of the present invention, a differential relay protection device is provided, the differential relay protection device comprising: a first clock module configured to create a first clock; a second clock module configured to create a second clock, wherein the first clock and the second clock operate independently; a transceiver module; and a processing module configured to perform the aforementioned method.

[0019] According to another aspect of the embodiments of the present invention, a power device is provided, the power device including: a differential relay protection device configured to perform the aforementioned method.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided having computer-executable instructions stored thereon, which, when executed by a processor, are used to implement the aforementioned method.

[0021] Other aspects, advantages, and salient features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments disclosed in conjunction with the accompanying drawings. Attached Figure Description

[0022] The invention will be more readily understood from the following detailed description with reference to the accompanying drawings, wherein like reference numerals designate units of the same structure, and wherein:

[0023] Figure 1 A schematic diagram of a substation including a differential relay protection device according to an embodiment of the present disclosure is shown;

[0024] Figure 2 A graph depicting the ratio between the second clock and the first clock according to an embodiment of the present disclosure is shown;

[0025] Figure 3 A schematic diagram is shown of a first plurality of sample data having a first plurality of sample counts and a second plurality of sample data having a second plurality of sample counts, according to an embodiment of the present disclosure;

[0026] Figure 4 A flowchart is shown of a method performed by a differential relay protection device according to an embodiment of the present disclosure;

[0027] Figure 5A A schematic diagram of a differential relay protection device according to an embodiment of the present disclosure is shown;

[0028] Figure 5B A schematic diagram of another differential relay protection device according to an embodiment of the present disclosure is shown; and

[0029] Figure 6 A schematic diagram of a non-transitory computer-readable medium according to an embodiment of the present disclosure is shown.

[0030] Throughout the accompanying drawings, similar reference numerals will be understood to refer to similar parts, components, and structures. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Furthermore, those skilled in the art will understand that the elements in the accompanying drawings are illustrated for simplicity and may not necessarily be drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to aid in understanding various aspects of the embodiments. Additionally, one or more elements may have been represented by various symbols in the drawings, and the drawings may only show those specific details relevant to understanding the embodiments of this disclosure, so as not to obscure details that are readily apparent to those skilled in the art who will benefit from the description herein.

[0033] Furthermore, it should be noted that in this specification, A connected to B can mean "A is directly connected to B" or "A is connected to B via other middleware". A connected between B and C can mean "A is directly connected to both B and C" or "A is connected to both B and C via other middleware".

[0034] Figure 1 A schematic diagram of a substation including a differential relay protection device according to an embodiment of the present disclosure is shown.

[0035] like Figure 1 As shown, substation 100 includes a clock unit 101, a differential relay protection device 102, and a merging unit (MU) 103, while substation 200 includes a clock unit 201 and a differential relay protection device 202. It should be understood that... Figure 1 The substation shown is merely an example; a substation system may include more than [examples of substations]. Figure 1 The diagram shows more or fewer substations, and the substations may include more than... Figure 1 The number of units may vary, with more or fewer shown. The following description uses substation 101 as an example.

[0036] In some embodiments, the various units in substation 100 can achieve time synchronization through a master-slave clock configuration. For example, clock unit 101 of substation 100 operates as the master clock (GMC), and differential relay protection device 102 and merging unit 103 each contain a clock unit and operate as slave clocks of clock unit 101. Time synchronization between the master and slave clocks can be achieved via Precision Time Protocol (PTP) or IRIG-B (inter-range instrumentation group-B) codes. In some embodiments, the master clock can obtain a standard time signal from Global Positioning System (GPS) satellites or from BeiDou navigation satellites.

[0037] In embodiments of this disclosure, the differential relay protection device 102 may have two independently operating (e.g., asynchronous) clocks. One clock may be synchronized with the clock unit 101 of the substation 100 to operate as a slave clock of the clock unit 101, or it may operate independently without synchronization with the clock unit 101 of the substation 100. The other clock is synchronized with corresponding clocks in other differential relay protection devices. Hereinafter, the former is referred to as the first clock, and the latter as the second clock. Those skilled in the art will understand that, according to embodiments of this disclosure, each differential relay protection device includes a first clock and a second clock. In some embodiments, synchronization between the second clocks in different differential relay protection devices may be achieved via PTP. Reference Figure 1 The second clock of the differential relay protection device 102 of substation 100 and the second clock of the differential relay protection device 202 of substation 200 can be synchronized via PTP. In some embodiments, substation 100 may include multiple differential relay protection devices, and the second clocks of these multiple differential relay protection devices can also be synchronized via PTP.

[0038] Furthermore, the differential relay protection device 102 can be driven by a first clock to sample electrical quantities in the substation 100 at a first sampling frequency fs1 based on the IEC61850-9-2 protocol to obtain a sampling result SV. The sampling result SV can include sample counts and sample data, wherein the sample counts correspond one-to-one with the sample data. The first sampling frequency fs1 is a predetermined sampling frequency, and in some embodiments, the first sampling frequency fs1 can be 4000Hz. However, this disclosure is not limited thereto, and those skilled in the art can use different sampling frequencies as needed. In some embodiments, the differential relay protection device 102 can receive the sampling result SV from the merging unit 103. Hereinafter, the sample counts included in the sampling result SV are referred to as the first plurality of sample counts, and the sample data included in the sampling result SV are referred to as the first plurality of sample data.

[0039] In some embodiments, the differential relay protection device 102 can map a first plurality of sample data having a first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts associated with a second clock. Figures 2 to 4 Specifically, this describes the process of mapping a first set of sample data with a first set of sample counts to a second set of sample data with a second set of sample counts.

[0040] Furthermore, the differential relay protection device 102 can also receive multiple sample data with a second plurality of sample counts from one or more other differential relay protection devices. For example, the differential relay protection device 102 of substation 100 can receive a third plurality of sample data with a second plurality of sample counts from the differential relay protection device 202 of substation 200. As another example, when substation 100 includes multiple differential relay protection devices, the differential relay protection device 102 can also receive multiple sample data with a second plurality of sample counts from other differential relay protection devices in substation 100. The differential relay protection device 102 can determine the differential current based on the second plurality of sample data and the multiple sample data received from one or more other differential relay protection devices, and determine whether a circuit fault has occurred based on the value of the differential current.

[0041] As mentioned earlier, the first clock of the differential relay protection device 102 in substation 100 and the first clock of the differential relay protection device 202 in substation 200 are usually not synchronized. Therefore, the first plurality of sample data with a first plurality of sample counts obtained by the differential relay protection device 102 in substation 100 under its first clock and the fourth plurality of sample data with a third plurality of sample counts obtained by the differential relay protection device 202 in substation 200 under its first clock are out of time alignment, making the calculation of differential current difficult. To address this, the differential relay protection device 102 in substation 100 can map the first plurality of sample data with a first plurality of sample counts to a second plurality of sample data with a second plurality of sample counts and send it to the differential relay protection device 202 in substation 200. Similarly, the differential relay protection device 202 in substation 200 can also map the fourth plurality of sample data with a third plurality of sample counts to a third plurality of sample data with a second plurality of sample counts and send it to the differential relay protection device 102 in substation 100. In this way, the second and third sets of sample data are aligned in time, which simplifies the calculation of differential current.

[0042] Similarly, when substation 100 includes multiple differential relay protection devices, the first clocks of these devices are typically asynchronous. Therefore, the electrical quantities sampled by the multiple differential relay protection devices under their respective first clocks are different sample data with different sample counts. As mentioned earlier, sample data with different sample counts can be mapped to sample data with the same sample count to simplify the calculation of differential current.

[0043] The merging unit 103 is a physical unit used for time-correlated combination of current and voltage data from the secondary converter. Figure 1 In this embodiment, the merging unit 103 is shown as a discrete unit, but in some embodiments, it may be a component of an instrument transformer. In some embodiments, the merging unit 103 may sample electrical quantities (e.g., voltage and / or current) in the substation 100 at a first sampling frequency fs1 based on the IEC61850-9-2 protocol, and send the sampling results to the differential relay protection device 102 via SV.

[0044] Figure 2 A graph depicting the ratio between the second clock and the first clock according to an embodiment of the present disclosure is shown.

[0045] Considering that the first clock and the second clock may have different frequencies, periods, phases, or duty cycles due to differences in structure, temperature, etc., that is, when the first clock has elapsed for 1 second, the second clock may have elapsed for more than 1 second or less than 1 second. Therefore, in order to map the first plurality of sample data with a first plurality of sample counts to the second plurality of sample data with a second plurality of sample counts, it is necessary to calculate the ratio between the second clock and the first clock.

[0046] like Figure 2 As shown, the horizontal axis represents the elapsed time t1 of the first clock, and the vertical axis represents the elapsed time t2 of the second clock. Three points T11, T12, and T13 are shown on the horizontal axis, representing three moments within the elapsed time of the first clock, where the time interval between T11 and T12 is 1 second, and the time interval between T12 and T13 is also 1 second. Similarly, three points T21, T22, and T23 are shown on the horizontal axis, representing three moments within the elapsed time of the second clock. As mentioned above, since the first and second clocks operate independently, the time lengths between T21 and T22, and between T22 and T23, may be more than or less than 1 second. In this case, the ratio between the second and first clocks can be calculated second by second. For example, for the 1 second between T11 and T12, the ratio r between the second and first clocks is... 21 It can be calculated using the following formula:

[0047]

[0048] For example, for 1 second between T12 and T13, the ratio r between the second clock and the first clock. 32 It can be calculated using the following formula:

[0049]

[0050] In some embodiments, whenever the first clock indicates an integer second, the current time of the second clock can be recorded, thereby calculating the ratio between the second clock and the first clock based on the recorded time of the second clock. In some embodiments, the time difference between the second clock and the first clock can also be calculated. For example, for the time T12 of the first clock, the time difference between the second clock and the first clock can be calculated as T22-T12. Furthermore, the calculated ratio and time difference between the second clock and the first clock can also be stored for use in the calculation process of mapping a first plurality of sample data having a first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts.

[0051] Figure 3 A schematic diagram is shown of a first plurality of sample data having a first plurality of sample counts and a second plurality of sample data having a second plurality of sample counts, according to an embodiment of the present disclosure.

[0052] Taking the time between T11 and T12 as an example, sampled at the first sampling frequency fs1, Figure 3 The upper part shows the first plurality of sample data with a first plurality of sample counts, where the horizontal axis represents the sample counts and the vertical axis represents the sample data. The horizontal axis shows the first plurality of sample counts k, k+1...k+N, and the first plurality of sample data with the first plurality of sample counts k, k+1...k+N are v respectively. k v k+1 ...v k+n , where k and N are both positive integers. The number of the first plurality of sample counts is related to the first sampling frequency fs1, and the first sampling frequency fs1 can be preset. For example, when the first sampling frequency fs1 is 4000Hz, the number of the first plurality of sample counts can be 4000.

[0053] like Figure 3 The lower half shows the first plurality of sample data v with the first plurality of sample counts k, k+1...k+N. k v k+1 ...v k+N The mapping yields a second set of sample data v with second-to-last sample counts j, j+1...j+M. j vj+1 ...v j+M The number of sample counts is related to the second sampling frequency fs2, and the second sampling frequency fs2 can be preset.

[0054] In some embodiments, the second plurality of sample counts j, j+1...j+M can be based on the first plurality of sample counts k, k+1...k+N and the ratio r between the second clock and the first clock. 21 The time difference T22-T12 between the second clock and the first clock, the first sampling frequency fs1, and the second sampling frequency fs2 are used to determine the sample count. First, the minimum sample count k and the maximum sample count k+N among the first plurality of sample counts are determined. A specific minimum sample count k′ and a specific maximum sample count (k+N)′ can be calculated based on the minimum sample count k and the maximum sample count k+N using the following formulas, where:

[0055]

[0056] Here, {·} is the decimal operator. Multiple positive integers j, j+1...j+M between k′ and (k+N)′ can be determined as the second plurality of sample counts. Typically, the number of the second plurality of sample counts is less than the number of the first plurality of sample counts.

[0057] In some embodiments, a second plurality of sample data v having a second plurality of sample counts j, j+1...j+M j v j+1 ...v j+M It can be based on the first multiple sample counts k, k+1...k+N, and the first multiple sample data v k v k+1 ...v k+N The ratio r between the second clock and the first clock 21 The time difference T22-T12 between the second clock and the first clock, the first sampling frequency fs1, and the second sampling frequency fs2 are used to determine the frequency.

[0058] Next, let's take sample data v with sample count j+1. j+1 As an example, describe the process of determining a second set of sample data.

[0059] For sample count j+1, the ratio r between the second clock and the first clock 21 The time difference T22-T12 between the second clock and the first clock, the first sampling frequency fs1 and the second sampling frequency fs2 determine the specific sample count (j+1)′ corresponding to the sample count j+1, where:

[0060]

[0061] Here, {·} is the decimal operator. For a specific sample count (j+1)′, determine the specific sample data v that has that specific sample count (j+1)′. (j+1)′ It can be based on a specific sample count (j+1)′, the first or more sample counts k, k+1...k+N, or the first or more sample data v. k v k+1 ...v k+N Determine specific sample data v (j+1)′ .

[0062] In some embodiments, the sample count among the first plurality of sample counts k, k+1...k+N that is numerically closest to a specific sample count (j+1)′ can be determined. For example, it can be k+1, in which case the sample data v with sample count k+1 can be... k+1 The specific sample data v is determined to have that specific sample count (j+1)′. (j+1)′ .

[0063] In other embodiments, two sample counts that are numerically adjacent to a specific sample count (j+1)′ among the first plurality of sample counts k, k+1...k+N can be determined, for example, k+1 and k+2. In this case, the sample data v with sample count k+1 can be used as a basis. k+1 and sample data v with sample count k+2 k+2 Perform linear interpolation to determine the specific sample data v with sample count (j+1)′. (j+1)′ .

[0064] Subsequently, this specific sample data v (j+1)′ The sample data v is determined to have a sample count of j+1. j+1 The second plurality of sample data v with second plurality of sample counts j, j+1...j+M can be determined in a similar manner. j v j+1 ...v j+M Each of them.

[0065] In the above manner, the first plurality of sample data v, which has a first plurality of sample counts k, k+1...k+N, obtained by sampling at a first sampling frequency fs1 under a first clock, can be processed. k v k+1 ...v k+N Map to a second set of sample data v with second-to-most sample counts j, j+1...j+M. j v j+1 ...v j+M The second plurality of sample counts are associated with a second clock that operates independently of the first clock.

[0066] Figure 4 A flowchart is shown of a method performed by a differential relay protection device according to an embodiment of the present disclosure.

[0067] In step 401, the differential relay protection device can obtain a first plurality of sample data having a first plurality of sample counts. As previously described, the differential relay protection device can have a first clock and a second clock, and the first clock operates independently of the second clock. Driven by the first clock, the differential relay protection device can sample electrical quantities in the substation at a first sampling frequency fs1 to obtain the first plurality of sample data having a first plurality of sample counts. Sampling can be based on the IEC61850-9-2 protocol. In some embodiments, the differential relay protection device can receive the first plurality of sample data having a first plurality of sample counts from a merging unit.

[0068] In step 402, the differential relay protection device can map a first plurality of sample data having a first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts. As previously mentioned, the first clock of the differential relay protection device can be synchronized with the main clock of the substation including the differential relay protection device or operate independently, and the second clock can be synchronized with the second clock of another differential relay protection device. For each differential relay protection device, mapping the first plurality of sample data with a first plurality of sample counts based on the first clock to the second plurality of sample data with a second plurality of sample counts based on the second clock allows each differential relay protection device to obtain sample data with the same sample counts, i.e., time-aligned sample data, thereby simplifying the calculation of differential current. In some embodiments, the calculation of differential current can be simplified to a vector sum of sample data from different differential relay protection devices. The foregoing has already been referenced Figures 2 to 3 The description details how to map a first set of sample data with a first set of sample counts to a second set of sample data with a second set of sample counts. To avoid redundancy, this will not be repeated here.

[0069] In step 403, the differential relay protection device can receive multiple sample data with a second plurality of sample counts from one or more other differential relay protection devices (such as differential relay protection devices in another substation or other differential relay protection devices in the same substation). As described in step 402, according to embodiments of the present disclosure, each differential relay protection device can map sample data with a plurality of sample counts, sampled at its respective first clock or received from the merging unit, to sample data with a uniform sample count. For example, return to reference Figure 1Differential relay protection device 102 can map a first plurality of sample data having a first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts, and differential relay protection device 202 can map a fourth plurality of sample data having a third plurality of sample counts to a third plurality of sample data having a second plurality of sample counts. Differential relay protection device 102 can receive a third plurality of sample data having a second plurality of sample counts, and similarly, differential relay protection device 202 can also receive a second plurality of sample data having a second plurality of sample counts.

[0070] In step 404, the differential relay protection device can determine the differential current based on a second plurality of sample data having a second plurality of sample counts and a plurality of sample data having a second plurality of sample counts received from one or more other differential relay protection devices. For example, return to reference. Figure 1 When differential relay protection device 102 receives a third plurality of sample data having a second plurality of sample counts from differential relay protection device 202, since both the second plurality of sample data and the third plurality of sample data have a second plurality of sample counts, i.e., the second plurality of sample data and the third plurality of sample data are time-aligned, differential relay protection device 102 can determine the differential current based on the second plurality of sample data having a second plurality of sample counts and the third plurality of sample data having a second plurality of sample counts. In some embodiments, the differential current can be determined by calculating the vector sum of the second plurality of sample data having a second plurality of sample counts and the third plurality of sample data having a second plurality of sample counts. Similarly, when differential relay protection device 202 also receives a second plurality of sample data having a second plurality of sample counts from differential relay protection device 102, the differential current can also be determined based on the second plurality of sample data having a second plurality of sample counts and the third plurality of sample data having a second plurality of sample counts. It should be understood that although this disclosure illustrates a system of two substations including differential relay protection devices, the method described in this disclosure can be applied to systems including more substations. Furthermore, although this disclosure illustrates the use of differential relay protection devices in different substations, the methods described herein are applicable to situations where multiple differential relay protection devices are present in the same substation. Moreover, while this disclosure uses a substation including differential relay protection devices as an example, the methods described herein are applicable to any electrical equipment and / or system including differential relay protection devices.

[0071] In step 405, the differential relay protection device can determine whether a circuit fault has occurred based on the value of the differential current. For example, when the value of the differential current is greater than a threshold, the differential relay protection device can determine that a circuit fault has occurred. When the differential relay protection device determines that a circuit fault has occurred, it can take timely measures to isolate the fault. In some embodiments, the threshold can be preset.

[0072] Figure 5A A schematic diagram of a differential relay protection device according to an embodiment of the present disclosure is shown.

[0073] like Figure 5A As shown, the differential relay protection device 500A may include a clock module 501A, a transceiver module 502A, and a processing module 503A. The clock module 501A can configure the differential relay protection device 500A with independently operating first and second clocks. The first clock may be a slave clock of the master clock of the substation where the differential relay protection device is located, and synchronized with the master clock, or it may be a free clock controlled by the crystal oscillator of the differential relay protection device itself. In some embodiments, the first clock may be synchronized with the master clock via the PTP protocol or IRIG-B code. The second clock may be synchronized with the second clocks of other differential relay protection devices. In some embodiments, the second clock may be synchronized with the second clocks of other differential relay protection devices via the PTP protocol. The transceiver module 502A can receive sampling results of electrical quantities (voltage and / or current) within the substation and electrical quantities of other differential relay protection devices from the merging unit, and can send the mapped second plurality of sample data with a second plurality of sample counts to other differential relay protection devices. The processing module 503A can perform reference... Figures 1 to 4 The described relay protection method.

[0074] In some embodiments, the differential relay protection device 500A may further include a sampling module for sampling electrical quantities within the substation. In some embodiments, the differential relay protection device 500A may further include a storage module for storing a second plurality of sample data with a second plurality of sample counts obtained through mapping.

[0075] Figure 5B A schematic diagram of another differential relay protection device according to an embodiment of the present disclosure is shown.

[0076] like Figure 5BAs shown, the differential relay protection device 500B may include a first clock module 501B, a second clock module 502B, a transceiver module 503B, and a processing module 504B. The first clock module 501B can configure a first clock for the differential relay protection device 500B, and the second clock module 502B can configure a second clock for the differential relay protection device 500B. The first clock and the second clock operate independently; that is, the first clock and the second clock are not synchronized. The first clock may be a slave clock of the master clock of the substation where the differential relay protection device is located, and synchronized with the master clock, or it may be a free clock controlled by the crystal oscillator of the differential relay protection device itself. In some embodiments, the first clock may be synchronized with the master clock via the PTP protocol or IRIG-B code. The second clock may be synchronized with the second clocks in other differential relay protection devices. In some embodiments, the second clock may be synchronized with the second clocks in other differential relay protection devices via the PTP protocol. The transceiver module 503B can receive sampling results of electrical quantities (voltage and / or current) within the substation and electrical quantities from other differential relay protection devices from the merging unit, and can send the mapped second-multiple sample data with a second-multiple sample count to other differential relay protection devices. The processing module 504B can perform reference... Figures 1 to 4 The described relay protection method.

[0077] Similar to the differential relay protection device 500A, the differential relay protection device 500B may also include a sampling module for sampling electrical quantities within the substation, and a storage module for storing a second plurality of sample data with a second plurality of sample counts obtained from the mapping.

[0078] Figure 6 A schematic diagram of a non-transitory computer-readable medium according to an embodiment of the present disclosure is shown.

[0079] like Figure 6 As shown, a non-transitory readable storage medium 600 stores computer instructions 610, which, when executed by a processor, perform one or more steps of the method for a differential relay protection device and its additional aspects as described above.

[0080] For example, the non-temporarily readable storage medium 600 may be any combination of one or more computer-readable storage media, such as a computer-readable storage medium containing program code for performing the various methods described above.

[0081] For example, when the program code is read by a computer, the computer can execute the program code stored in the computer storage medium to perform one or more steps of the various methods and additional aspects described above, such as those according to at least one embodiment of the present disclosure.

[0082] Those skilled in the art will recognize that the units and algorithm steps of the various embodiments described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each embodiment have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0083] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0084] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0085] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0086] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0087] If the integrated unit is implemented as 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 invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0088] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method executed by a differential relay protection device, comprising: Obtain first plurality of sample data having a first plurality of sample counts, wherein the first plurality of sample counts are associated with a first clock in the differential relay protection device; The first plurality of sample data having a first plurality of sample counts is mapped to a second plurality of sample data having a second plurality of sample counts, wherein the second plurality of sample counts are associated with a second clock in the differential relay protection device, and the first clock and the second clock operate independently; Receive multiple sample data with a second plurality of sample counts from one or more other differential relay protection devices; The differential current is determined based on the second set of sample data and the set of sample data; and The value of the differential current is used to determine whether a circuit fault has occurred.

2. The method according to claim 1, wherein, Obtaining the first plurality of sample data with the first plurality of sample counts includes: The differential relay protection device samples data based on a first sampling frequency at a first clock cycle to obtain a first plurality of sample data; or The differential relay protection device receives a first plurality of sample data from the merging unit, which are sampled by the merging unit at a first sampling frequency under a first clock. The first sampling frequency is a predetermined sampling frequency.

3. The method according to claim 1, wherein, The sample data are electrical quantities.

4. The method according to claim 1, mapping a first plurality of sample data having a first plurality of sample counts to a second plurality of sample data having a second plurality of sample counts comprises: Determine the ratio and time difference between the second clock and the first clock; The second set of sample counts is determined based on the first set of sample counts. as well as Based on the ratio, the time difference, the first plurality of sample counts, the first plurality of sample data, and the second plurality of sample counts, a second plurality of sample data with a second plurality of sample counts is determined.

5. The method according to claim 4, wherein, Determining the ratio and time difference between the second clock and the first clock includes, for every second elapsed in the first clock: The ratio of the elapsed time of the second clock to the elapsed time of the first clock is determined as the ratio between the first and second clocks in seconds; as well as The difference between the current time of the second clock and the current time of the first clock is determined as the time difference between the first and second clocks in seconds.

6. The method according to claim 4, wherein, Determining the second set of sample counts based on the first set of sample counts includes: Determine the maximum and minimum sample counts among the first plurality of sample counts; For each of the maximum and minimum sample counts, a specific maximum sample count and a specific minimum sample count corresponding to the maximum and minimum sample counts, respectively, are determined based on the ratio, the time difference, the first sampling frequency, and the second sampling frequency; and The integer between a specific maximum sample count and a specific minimum sample count is determined as the second plurality of sample counts. The second sampling frequency is a predetermined sampling frequency.

7. The method according to claim 4, wherein, Determining the second plurality of sample data with the second plurality of sample counts based on the ratio, the time difference, the first plurality of sample counts, the first plurality of sample data, and the second plurality of sample counts includes, for each sample count in the second plurality of sample counts: A specific sample count corresponding to the sample count is determined based on the ratio, the time difference, the first sampling frequency, and the second sampling frequency. Based on the first plurality of sample counts, the first plurality of sample data, and the specific sample count, determine the specific sample data with the specific sample count; as well as The specific sample data is determined to be sample data with the specified sample count.

8. The method according to claim 7, wherein, Determining specific sample data with a specific sample count based on a first plurality of sample counts, a first plurality of sample data, and a specific sample count includes: Among the first plurality of sample counts, determine the sample count that is numerically closest to a specific sample count; and The sample data with the stated sample count is identified as specific sample data.

9. The method according to claim 7, wherein, Determining specific sample data with a specific sample count based on a first plurality of sample counts, a first plurality of sample data, and a specific sample count includes: Among the first plurality of sample counts, identify two sample counts that are numerically adjacent to a specific sample count; and Interpolation is performed on two sample data with the two sample counts to determine a specific sample data.

10. The method according to claim 1, wherein, The second clock is the Precision Time Protocol (PTP) clock.

11. The method according to claim 1, wherein, Determining whether a circuit fault has occurred based on the value of the differential current includes: When the value of the differential current is greater than the threshold, a circuit fault is determined to have occurred.

12. The method according to claim 1, further comprising: Store second-more sample data with a second-more sample count; as well as Send a second plurality of sample data with a second plurality of sample counts to one or more other differential relay protection devices.

13. A differential relay protection device, comprising: The clock module is configured to create a first clock and a second clock, wherein the first clock and the second clock operate independently; Transceiver module; and The processing module is configured to perform the method according to any one of claims 1-12.

14. A differential relay protection device, comprising: The first clock module is configured to create the first clock; The second clock module is configured to create a second clock, wherein the first clock and the second clock operate independently; Transceiver module; and The processing module is configured to perform the method according to any one of claims 1-12.

15. An electrical device, comprising: A differential relay protection device is configured to perform the method of any one of claims 1-12.

16. A computer-readable storage medium having stored thereon computer-executable instructions, which, when executed by a processor, are used to implement the method of any one of claims 1-12.

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