Differential protection method and system

Abstract

The invention provides a differential protection method and system, and the method comprises the steps: carrying out the time synchronization of a first differential device and a second differential device through an external clock, enabling the second pulse moments of the first differential device and the second differential device to be absolutely synchronized, and determining the current second pulse moment; the first differential device sends a first data frame to the second differential device; the first differential device calculates the relative sending time of the first data frame by using the sending time of the first data frame and the current second pulse time; the second differential device calculates the relative receiving time of the first data frame by using the receiving moment of the first data frame and the current second pulse moment; the second differential device calculates channel delay by using the calculated relative receiving time of the first data frame and the relative sending time of the first data frame calculated by the first differential device; and the second differential device performs differential calculation by using the channel delay.

Description

Technical Field

[0001] The present application relates to the field of electrical engineering, and in particular to a differential protection method and system. Background Art

[0002] Longitudinal differential protection has the advantages of clear protection range, simple principle, stability and reliability. With the development of communication technology, differential protection has been widely used. Differential protection uses the communication network to exchange information, transmits information such as the current on the opposite side to the local side, calculates the differential current and braking current based on the current on the local side and the opposite side, and determines whether it is an internal fault based on the differential action characteristics.

[0003] The premise of the correct operation of differential protection is data synchronization, so the data synchronization technology on both sides is the key to realize differential protection. The commonly used synchronization method for line differential protection is the ping-pong principle method. This method does not rely on an external timing source, is stable and reliable, and is widely used in differential protection. However, the premise of using this method is that the channel receiving and sending delays must be consistent.

[0004] In order to improve the reliability of differential protection data transmission, the communication network generally has a self-healing function. That is, when the communication equipment fails, it can automatically switch the channel route in a very short time. At this time, the delay of the sending and receiving route may be inconsistent. If the channel sending and receiving delay is inconsistent, the prerequisite of the ping-pong principle method will be destroyed, which will cause false synchronization and affect the reliability of differential protection. In extreme cases, it will cause differential protection malfunction. Summary of the invention

[0005] The present application proposes a differential protection method and system to solve the problem of inconsistent transmission and reception delays in a differential protection system.

[0006] According to one aspect of the present application, a differential protection method is proposed, which is applied to a differential protection system, wherein the differential protection system includes a first differential device and a second differential device, and the differential protection method includes: using an external clock to synchronize the first differential device and the second differential device so that the second pulse moments of the first differential device and the second differential device are absolutely synchronized to determine the current second pulse moment; the first differential device sends a first data frame to the second differential device; the first differential device calculates the relative sending time of the first data frame using the sending moment of the first data frame and the current second pulse moment; the second differential device calculates the relative receiving time of the first data frame using the receiving moment of the first data frame and the current second pulse moment; the second differential device calculates the channel delay using the calculated relative receiving time of the first data frame and the relative sending time of the first data frame calculated by the first differential device; and the second differential device performs differential calculation using the channel delay.

[0007] According to some embodiments, the first differential device uses the sending time of the first data frame and the current second pulse time to calculate the relative sending time of the first data frame, including: the first differential device uses the sending time of the first data frame to subtract the current second pulse time to obtain the relative sending time of the first data frame; and / or the second differential device uses the receiving time of the first data frame and the current second pulse time to calculate the relative receiving time of the first data frame, including: the second differential device uses the receiving time of the first data frame to subtract the current second pulse time to obtain the relative receiving time of the first data frame.

[0008] According to some embodiments, when the sending time of the first data frame and the receiving time of the first data frame span seconds, the second differential device uses the receiving time of the first data frame and the current second pulse time to calculate the relative receiving time of the first data frame, and also includes: adding a preset time length to the relative receiving time of the first data frame.

[0009] According to some embodiments, the second differential device calculates the channel delay using the calculated relative reception time of the first data frame and the relative transmission time of the first data frame calculated by the first differential device, including: the second differential device subtracts the relative transmission time of the first data frame from the relative reception time of the first data frame to obtain the channel delay.

[0010] According to some embodiments, the second differential device uses the channel delay to perform differential calculation, including: the second differential device uses the channel delay to obtain differential calculation data synchronized with the first data frame; the second differential device uses the differential calculation data to perform differential calculation.

[0011] According to some embodiments, the second differential device uses the channel delay to obtain differential calculation data synchronized with the first data frame, including: the second differential device uses the channel delay to calculate the relative time position; the second differential device obtains adjacent sampling data adjacent to the relative time position; the second differential device uses the adjacent sampling data to perform interpolation calculation to obtain differential calculation data synchronized with the first data frame.

[0012] According to some embodiments, the second differential device calculates the relative time position using the channel delay, including: subtracting the channel delay from the relative receiving time of the first data frame to obtain the relative time position.

[0013] According to some embodiments, the second differential device uses the channel delay to calculate the relative time position, and also includes: the second differential device uses the relative reception time of the first data frame to subtract the channel delay to obtain an intermediate value of the relative time position; the second differential device uses the intermediate value of the relative time position to subtract a preset inherent delay to obtain the relative time position.

[0014] According to some embodiments, the interpolation calculation is performed by the following formula:

[0015]

[0016] Among them, tmsyn is the relative time position, sdm1 is the first sampling data, sdm2 is the second sampling data, Tsdm1 is the relative sampling time of the first sampling data, Tsdm2 is the relative sampling time of the second sampling data, Vsdm1 is the sampling value of the first sampling data, and Vsdm2 is the sampling value of the second sampling data.

[0017] According to some embodiments, the differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to sync the first differential device, and the second external clock is used to sync the second differential device. The differential protection method also includes: real-time monitoring of the sync status of the first differential device and the sync status of the second differential device, and when it is detected that the sync status of the first differential device or the sync status of the second differential device is abnormal, doubling the preset differential action threshold.

[0018] According to some embodiments,

[0019] The differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to sync the first differential device, and the second external clock is used to sync the second differential device. When it is monitored that the sync state of the first differential device or the sync state of the second differential device is abnormal, before the second differential device uses the channel delay to perform differential calculation, the differential protection method also includes: calculating the second pulse deviation of the first differential device and the second differential device; and compensating the current second pulse moment using the second pulse deviation.

[0020] According to some embodiments, calculating the pulse-per-second deviation of the first differential device and the second differential device includes: using the relative transmission time of the first data frame plus the channel delay minus the relative reception time of the first data frame to obtain the pulse-per-second deviation.

[0021] According to some embodiments, compensating the current pulse-per-second moment by using the pulse-per-second deviation includes: subtracting the pulse-per-second deviation from the current pulse-per-second moment to obtain the compensated current pulse-per-second moment.

[0022] According to some embodiments, the differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to sync the first differential device, and the second external clock is used to sync the second differential device, and the differential protection method also includes: real-time monitoring of the sync status of the first differential device and the second differential device, and locking the differential protection when it is detected that both the sync status of the first differential device and the sync status of the second differential device are abnormal.

[0023] According to some embodiments, the differential protection method also includes: the second differential device sends a second data frame to the first differential device; the second differential device uses the sending time of the second data frame and the current second pulse time to calculate the relative sending time of the second data frame; the first differential device uses the receiving time of the second data frame and the current second pulse time to calculate the relative receiving time of the second data frame; the first differential device uses the calculated relative receiving time of the second data frame and the relative sending time of the second data frame calculated by the second differential device to calculate the channel delay; and the first differential device uses the channel delay to perform differential calculation.

[0024] According to one aspect of the present application, an electronic device is provided, comprising: a processor; and a memory storing a computer program, wherein when the computer program is executed by the processor, the processor executes the method described in any of the preceding embodiments.

[0025] According to one aspect of the present application, a non-transitory computer-readable storage medium is provided, on which computer-readable instructions are stored. When the instructions are executed by a processor, the processor executes the method described in any of the previous embodiments.

[0026] According to the embodiments of the present application, the channel delay is calculated through external timing to achieve data synchronization on both sides, overcome the problem of inconsistent sending and receiving delays, improve the application scope of differential protection, and improve the safety and reliability of differential protection in the case of inconsistent channel sending and receiving delays.

[0027] According to other embodiments, by real-time monitoring of the external timing status, corresponding measures are taken immediately when abnormalities are found, thereby improving the reliability and stability of the differential protection.

[0028] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. By describing the exemplary embodiments in detail with reference to the drawings, the above and other objectives, features and advantages of the present application will become more apparent.

[0030] Figure 1 A schematic diagram of a differential protection communication and timing system according to an exemplary embodiment of the present application is shown.

[0031] Figure 2 A flow chart of a differential protection method according to an exemplary embodiment of the present application is shown.

[0032] Figure 3 A data synchronization schematic diagram of a differential protection method according to an exemplary embodiment of the present application is shown.

[0033] Figure 4 A schematic diagram showing the transmission and reception of a data frame across seconds according to an exemplary embodiment of the present application is shown.

[0034] Figure 5 A schematic diagram of pulse-per-second jump compensation after clock loss according to an exemplary embodiment of the present application is shown.

[0035] Figure 6 A block diagram of a differential protection system according to an exemplary embodiment of the present application is shown.

[0036] Figure 7 An electronic device according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0037] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. In the figures, the same figures show the same or similar parts, and thus their repeated description will be omitted.

[0038] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices or operations may be adopted. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0039] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0040] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0041] The specific embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0042] Figure 1 A schematic diagram of a differential protection communication and timing system according to an exemplary embodiment of the present application is shown. Figure 1 The differential protection system shown includes a differential device M and a differential device N, and two external clocks, which are connected to the differential device M or the differential device N respectively.

[0043] According to an embodiment of the present application, Figure 1 The differential device M and the differential device N on both sides of the differential protection system shown are synchronized by an external clock, so that the second pulse moments of the differential devices on both sides are absolutely synchronized, the data frame relative sending time is calculated by using the data frame sending time and the current second pulse moment, the data frame relative receiving time is calculated by using the data frame receiving time and the current second pulse moment, the data frame relative sending time is transmitted to the opposite device, the channel delay is calculated by using the data frame relative receiving time on this side and the data frame relative sending time on the opposite side, and the data on this side synchronized with the sampling data on the opposite side is obtained according to the channel delay for differential calculation, when the external clock on either side is lost, the differential action threshold is immediately raised, and the second pulse deviation on both sides is calculated, and the second pulse on the clock-lost side is compensated, when the external clocks on both sides are lost, an alarm is immediately sounded and the differential protection is locked, thereby overcoming the problem of inconsistent sending and receiving delays, improving the application scope of differential protection, and improving the safety and reliability of differential protection in the case of inconsistent channel sending and receiving delays.

[0044] Figure 2 A flow chart of a differential protection method according to an exemplary embodiment of the present application is shown. Figure 3 A schematic diagram of a data synchronization method for differential protection according to an exemplary embodiment of the present application is shown below. Figure 2 and Figure 3 Taking as an example, a differential protection method according to an exemplary embodiment of the present application is described in detail.

[0045] like Figure 2 The differential protection method shown is applied to a differential protection system, wherein the differential protection system includes a first differential device and a second differential device. In step S201, the first differential device and the second differential device are timed using an external clock so that the second pulse moments of the first differential device and the second differential device are absolutely synchronized to determine the current second pulse moment.

[0046] According to an embodiment of the present application, the first differential device and the second differential device receive external clock signals respectively through a timing interface. According to some embodiments, the external clock connected is a global clock. After the first differential device and the second differential device are successfully timed, the second pulses on both sides are absolutely synchronized, such as Figure 2 As shown in Tp0 and Tp1.

[0047] After the first differential device and the second differential device of the differential protection system are successfully timed, a data frame needs to be sent to the differential device on the opposite side through the differential device on the local side to calculate the channel delay. After executing step S201, step S203 is executed.

[0048] In step S203, the first differential device sends a first data frame to the second differential device.

[0049] After sending the first data frame, the first differential device executes step S205 to calculate the relative sending time of the first data frame using the sending time of the first data frame.

[0050] In step S205, the first differential device calculates the relative sending time of the first data frame by using the sending time of the first data frame and the current second pulse time.

[0051] After receiving the first data frame sent by the first differential device, the second differential device executes step S207 to calculate the relative receiving time of the first data frame using the receiving time of the first data frame.

[0052] In step S207, the second differential device calculates the relative receiving time of the first data frame by using the receiving time of the first data frame and the current second pulse time.

[0053] According to an embodiment of the present application, in step S205, the first differential device uses the sending time of the first data frame to subtract the current second pulse time to obtain the relative sending time of the first data frame. In step S207, the second differential device uses the receiving time of the first data frame to subtract the current second pulse time to obtain the relative receiving time of the first data frame.

[0054] like Figure 3 As shown, Tp0 is the current second pulse time, tns is the sending time of the data frame sdn1 of the N-side device, tmr is the time when the M-side device receives the data frame sdn1, and the calculation method of the relative sending time ΔTns of the data frame on the N side and the relative receiving time ΔTmr of the data frame on the M side is shown in formula (1).

[0055]

[0056] According to other embodiments of the present application, when the sending time of the first data frame and the receiving time of the first data frame span seconds, the relative receiving time of the first data frame calculated by formula (1) is increased by a preset time length, as shown in formula (2).

[0057] ΔTmr=ΔTmr+ΔT (2)

[0058] Here, ΔT is a preset time length, for example, 1 second.

[0059] like Figure 4 As shown, assuming that the second pulse time corresponding to the sending time of the first data frame sent by the N-side differential device N is Tp0, and the second pulse time corresponding to the receiving time of the first data frame by the M-side differential device M is Tp1, it is considered that the first data frame crosses seconds during the transmission process. After the M-side obtains the relative receiving time of the first data frame through formula (1), the M-side executes formula (2) to increase the preset time length for the relative receiving time. For example, 1 second.

[0060] After executing step S205 and step S207, the first differential device transmits the calculated relative sending time of the first data frame to the second differential device.

[0061] For example, Figure 2 As shown, the calculated relative transmission time of the N-side data frame sdn1 is ΔTns. After the relative transmission time is obtained, the relative transmission time and the first data frame are sent to the M-side differential device.

[0062] After the first differential device sends the relative sending time of the first data frame to the second differential device, step S209 is performed.

[0063] In step S209, the second differential device calculates a channel delay by using the calculated relative receiving time of the first data frame and the relative sending time of the first data frame calculated by the first differential device.

[0064] According to some embodiments, the second differential device uses the relative reception time of the first data frame minus the relative transmission time of the first data frame to obtain the channel delay.

[0065] like Figure 3 As shown, the relative time when the M side receives the first data frame is ΔTmr, the N side relative sending time ΔTns extracted from the first data frame, and the calculation method of the M side channel delay Tmd are shown in formula (3).

[0066] Tmd=ΔTmr-ΔTns (3)

[0067] In step S211, the second differential device performs differential calculation using the channel delay.

[0068] According to an embodiment of the present application, in step S211, the second differential device first uses the channel delay to obtain differential calculation data synchronized with the first data frame, and then performs differential calculation using the differential calculation data.

[0069] According to some embodiments, the second differential device obtains differential calculation data by the following steps:

[0070] First, the second differential device calculates the relative time position using the channel delay.

[0071] For example, the relative time position is obtained by subtracting the channel delay from the relative receiving time of the first data frame.

[0072] For another example, the second differential device uses the relative receiving time of the first data frame to subtract the channel delay to obtain the intermediate value of the relative time position; the second differential device uses the intermediate value of the relative time position to subtract a preset inherent delay to obtain the relative time position.

[0073] Then, the second differential device acquires adjacent sampling data adjacent to the relative time position;

[0074] Finally, the second differential device performs interpolation calculation using the adjacent sampling data to obtain differential calculation data synchronized with the first data frame.

[0075] like Figure 3 As shown, the relative receiving time ΔTmr of the data frame on the M side is subtracted from the channel delay Tmd, and then the fixed delay Tc of data transmission is subtracted to obtain the relative time position tmsyn of the M side synchronized with the sampling data sdn1 on the N side, and the two sampling data sdm1 and sdm2 adjacent to the time position are obtained. The two sampling data are used for interpolation calculation to obtain the sampling data on the M side synchronized with the sampling data sdn1 on the N side. Finally, the differential calculation is performed using the synchronized data on both sides.

[0076] According to some embodiments, when performing interpolation calculation, linear interpolation is performed using the two sampling data points before and after the calculated relative time position. Figure 3 As shown, the two sampling data before and after the relative time position tmsyn on the M side are sdm1 and sdm2. Let the time and sampling value of the sampling data sdm1 relative to the second pulse Tp0 be Tsdm1 and Vsdm1 respectively, and the time and sampling value of the sampling data sdm2 relative to the second pulse Tp0 be Tsdm2 and Vsdm2 respectively. The synchronized sampling value Vsdm obtained by linear interpolation is as shown in formula (4).

[0077]

[0078] Among them, tmsyn is the relative time position, sdm1 is the first sampling data, sdm2 is the second sampling data, Tsdm1 is the relative sampling time of the first sampling data, Tsdm2 is the relative sampling time of the second sampling data, Vsdm1 is the sampling value of the first sampling data, and Vsdm2 is the sampling value of the second sampling data.

[0079] So far, according to Figure 2 In the illustrated embodiment, the second differential device calculates the channel delay through external timing to overcome the problem of inconsistent transmission and reception delays.

[0080] According to an embodiment of the present application, Figure 2 The method shown also includes the first differential device using external timing to calculate the channel delay to achieve data synchronization on both sides and overcome the problem of inconsistent reception and transmission delays, specifically: the second differential device sends a second data frame to the first differential device, the second differential device uses the sending time of the second data frame and the current second pulse time to calculate the relative sending time of the second data frame, the first differential device uses the receiving time of the second data frame and the current second pulse time to calculate the relative receiving time of the second data frame, the first differential device uses the calculated relative receiving time of the second data frame and the relative sending time of the second data frame calculated by the second differential device to calculate the channel delay, and the first differential device uses the channel delay to perform differential calculation.

[0081] according to Figure 2 In the embodiment shown, the channel delay is calculated through external timing to achieve data synchronization on both sides, thereby transmitting information such as the current on the opposite side to this side, calculating the differential current and braking current based on the currents on this side and the opposite side, and judging whether it is an intra-zone fault based on the differential action characteristics, thereby overcoming the problem of inconsistent sending and receiving delays, expanding the application scope of differential protection, and improving the safety and reliability of differential protection in the case of inconsistent channel sending and receiving delays.

[0082] According to an embodiment of the present application, the differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to synchronize the first differential device, and the second external clock is used to synchronize the second differential device. Figure 2 The differential protection method shown also includes: real-time monitoring of the synchronization status of the first differential device and the synchronization status of the second differential device, and when it is monitored that the synchronization status of the first differential device or the synchronization status of the second differential device is abnormal, doubling the preset differential action threshold.

[0083] According to some other embodiments of the present application, the differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to synchronize the first differential device, and the second external clock is used to synchronize the second differential device. When the synchronization state of the first differential device or the synchronization state of the second differential device is detected to be abnormal, before the second differential device uses the channel delay to perform differential calculation, the differential protection method further includes: calculating the second pulse deviation of the first differential device and the second differential device; using the second pulse deviation to compensate the current second pulse moment. That is, the second pulse deviation on both sides is calculated to compensate for the second pulse on the clock loss side. Taking the clock loss side as a reference, the relative receiving time of the data frame on this side is reversed using the calculated channel delay and the relative sending time of the opposite side data frame, and the calculated relative receiving time is compared with the actually calculated relative receiving time to obtain the time deviation of the second pulse on the clock loss side and the second pulse on the opposite side, and compensate for the second pulse on the clock loss side.

[0084] For example, the relative sending time of the first data frame plus the channel delay minus the relative receiving time of the first data frame is used to obtain the second pulse deviation, and the second pulse deviation is subtracted from the current second pulse time to obtain the compensated current second pulse time. Figure 5 As shown in the figure, assuming that the clock on the M side is lost, the second pulse on the M side jumps from Tp1 to Tp1′. According to the calculated channel delay Tmd and the relative sending time ΔTns1 of the data frame on the N side, the relative receiving time on the M side is deduced to be ΔTns1+Tmd. Then, the difference is made with the actual calculated relative receiving time ΔTmr1 to obtain the second pulse time deviation on both sides as shown in formula (5).

[0085] Toffset=ΔTns1+Tmd-ΔTmr1 (5)

[0086] After calculating the time deviation Toffset between the second pulse on the clock-lost side and the second pulse on the opposite side, the deviation is used as the compensation amount, and the deviation Toffset is fixedly subtracted from the second pulse on this side to obtain the second pulse time before the jump. Figure 5 As shown in FIG. 6 , after the external time synchronization is lost, the second pulse on the M side changes from Tp1 to Tp1′. After compensating Tp1′, Tp1 is obtained. The calculation method is shown in formula (6).

[0087] Tp1=Tp1′-Toffset (6)

[0088] According to an embodiment of the present application, the differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to synchronize the first differential device, and the second external clock is used to synchronize the second differential device. Figure 2 The differential protection method shown also includes: real-time monitoring of the timing status of the first differential device and the second differential device, and when it is detected that the timing status of the first differential device and the timing status of the second differential device are both abnormal, locking the differential protection. For example, the devices on both sides monitor the external clock status in real time and exchange clock status information on both sides. When it is detected that the external timing of both sides is lost, an alarm signal is immediately issued and the differential protection is locked.

[0089] The above mainly introduces the embodiments of the present application from the perspective of the method. Those skilled in the art should easily appreciate that, in combination with the operations or steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Those skilled in the art can use different ways to implement the described functions for each specific operation or method, and such implementation should not be considered to be beyond the scope of the present application.

[0090] The following describes the device embodiments of the present application. For details not described in the device embodiments of the present application, reference can be made to the method embodiments of the present application.

[0091] Figure 6 A block diagram of a differential protection system according to an exemplary embodiment of the present application is shown, wherein: Figure 6 The differential protection system includes a first differential device 601 , a second differential device 603 , an external clock 605 and a timing unit 607 .

[0092] According to an embodiment of the present application, the timing unit 607 is used to synchronize the first differential device 601 and the second differential device 603 using an external clock 605, so that the second pulse moments of the first differential device 601 and the second differential device 603 are absolutely synchronized to determine the current second pulse moment; the first differential device 601 is used to send a first data frame to the second differential device 603, and the relative sending time of the first data frame is calculated using the sending time of the first data frame and the current second pulse moment;

[0093] The second differential device 603 is used to calculate the relative reception time of the first data frame using the reception time of the first data frame and the current second pulse time, calculate the channel delay using the calculated relative reception time of the first data frame and the relative transmission time of the first data frame calculated by the first differential device 601, and perform differential calculation using the channel delay.

[0094] Figure 7 An electronic device according to an exemplary embodiment of the present application is shown. Figure 7 The electronic device 200 according to this embodiment of the present application is described. Figure 7 The electronic device 200 shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0095] like Figure 7 As shown, the electronic device 200 is in the form of a general computing device. The components of the electronic device 200 may include, but are not limited to: at least one processing unit 210, at least one storage unit 220, a bus 230 connecting different system components (including the storage unit 220 and the processing unit 210), a display unit 240, etc.

[0096] The storage unit stores program codes, which can be executed by the processing unit 210, so that the processing unit 210 executes the methods described in this specification according to various exemplary embodiments of the present application. For example, the processing unit 210 can execute the following: Figure 1 The method shown in .

[0097] The storage unit 220 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 2201 and / or a cache memory unit 2202 , and may further include a read-only memory unit (ROM) 2203 .

[0098] The storage unit 220 may also include a program / utility 2204 having a set (at least one) of program modules 2205, such program modules 2205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0099] Bus 230 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0100] The electronic device 200 may also communicate with one or more external devices 300 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 200, and / or communicate with any device that enables the electronic device 200 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 250. Furthermore, the electronic device 200 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 260. The network adapter 260 may communicate with other modules of the electronic device 200 via the bus 230. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 200, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0101] Through the description of the above implementation methods, it is easy for those skilled in the art to understand that the example implementation methods described here can be implemented by software or by combining software with necessary hardware. The technical solution according to the implementation method of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to execute the above method according to the implementation method of the present application.

[0102] The software product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0103] Computer readable storage media may include data signals propagated in baseband or as part of a carrier wave, wherein readable program codes are carried. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, device, or device. The program codes contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0104] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0105] The computer-readable medium carries one or more programs. When the one or more programs are executed by a device, the computer-readable medium implements the aforementioned functions.

[0106] Those skilled in the art will appreciate that the above modules can be distributed in the device according to the description of the embodiment, or can be changed accordingly and only used in one or more devices different from the embodiment. The modules of the above embodiments can be combined into one module, or further divided into multiple sub-modules.

[0107] According to an embodiment of the present application, a computer program is provided, including a computer program or an instruction. When the computer program or the instruction is executed by a processor, the method described above can be executed.

[0108] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. A differential protection method, characterized in that: The method is applied to a differential protection system, the differential protection system comprises a first differential device and a second differential device, and the differential protection method comprises: Using an external clock to synchronize the first differential device and the second differential device, so that the second pulse moments of the first differential device and the second differential device are absolutely synchronized, so as to determine the current second pulse moment; The first differential device sends a first data frame to the second differential device; The first differential device calculates the relative sending time of the first data frame by using the sending time of the first data frame and the current second pulse time; The second differential device calculates the relative reception time of the first data frame by using the reception time of the first data frame and the current second pulse time; The second differential device calculates a channel delay using the calculated relative reception time of the first data frame and the relative transmission time of the first data frame calculated by the first differential device; and The second differential means performs differential calculation using the channel delay.

2. The differential protection method according to claim 1, characterized in that: The first differential device calculates the relative sending time of the first data frame by using the sending time of the first data frame and the current second pulse time, including: The first differential device obtains the relative sending time of the first data frame by subtracting the current second pulse time from the sending time of the first data frame; and / or The second differential device calculates the relative receiving time of the first data frame by using the receiving time of the first data frame and the current second pulse time, including: The second differential device obtains the relative receiving time of the first data frame by subtracting the current second pulse time from the receiving time of the first data frame.

3. The differential protection method according to claim 2, characterized in that: When the sending time of the first data frame and the receiving time of the first data frame span seconds, the second differential device calculates the relative receiving time of the first data frame by using the receiving time of the first data frame and the current second pulse time, and further includes: A preset time length is added to the relative receiving time of the first data frame.

4. The differential protection method according to claim 1, characterized in that: The second differential device calculates the channel delay using the calculated relative receiving time of the first data frame and the relative sending time of the first data frame calculated by the first differential device, comprising: The second differential device uses the relative receiving time of the first data frame to subtract the relative sending time of the first data frame to obtain the channel delay.

5. The differential protection method according to claim 1, characterized in that: The second differential device performs differential calculation using the channel delay, including: The second differential device uses the channel delay to obtain differential calculation data synchronized with the first data frame; The second differential device performs differential calculation using the differential calculation data.

6. The differential protection method according to claim 5, characterized in that: The second differential device uses the channel delay to obtain differential calculation data synchronized with the first data frame, including: The second differential device calculates the relative time position using the channel delay; The second differential device acquires adjacent sampling data adjacent to the relative time position; The second differential device performs interpolation calculation using the adjacent sampling data to obtain differential calculation data synchronized with the first data frame.

7. The differential protection method according to claim 6, characterized in that: The second differential device calculates the relative time position using the channel delay, comprising: The relative time position is obtained by subtracting the channel delay from the relative receiving time of the first data frame.

8. The differential protection method according to claim 6, characterized in that: The second differential device calculates the relative time position using the channel delay, and further comprises: The second differential device uses the relative receiving time of the first data frame to subtract the channel delay to obtain an intermediate value of the relative time position; The second differential device uses the intermediate value of the relative time position to subtract a preset inherent delay to obtain the relative time position.

9. The differential protection method according to claim 6, characterized in that: The interpolation calculation is performed by the following formula: Among them, tmsyn is the relative time position, sdm1 is the first sampling data, sdm2 is the second sampling data, Tsdm1 is the relative sampling time of the first sampling data, Tsdm2 is the relative sampling time of the second sampling data, Vsdm1 is the sampling value of the first sampling data, and Vsdm2 is the sampling value of the second sampling data.

10. The differential protection method according to claim 1, characterized in that: The differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to sync the first differential device, and the second external clock is used to sync the second differential device. The differential protection method also includes: real-time monitoring of the sync status of the first differential device and the sync status of the second differential device, and when it is detected that the sync status of the first differential device or the sync status of the second differential device is abnormal, doubling the preset differential action threshold.

11. The differential protection method according to claim 1, characterized in that: The differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to synchronize the first differential device, and the second external clock is used to synchronize the second differential device. When it is detected that the synchronization state of the first differential device or the synchronization state of the second differential device is abnormal, before the second differential device performs differential calculation using the channel delay, the differential protection method further includes: calculating a pulse-per-second deviation of the first differential device and the second differential device; The current pulse-per-second moment is compensated using the pulse-per-second deviation.

12. The differential protection method according to claim 11, characterized in that: Calculating the pulse-per-second deviation of the first differential device and the second differential device comprises: The pulse-per-second deviation is obtained by adding the channel delay to the relative sending time of the first data frame and subtracting the relative receiving time of the first data frame.

13. The differential protection method according to claim 11, characterized in that: Compensating the current pulse-per-second moment by using the pulse-per-second deviation includes: The current pulse-per-second time is subtracted from the pulse-per-second deviation to obtain the compensated current pulse-per-second time.

14. The differential protection method according to claim 1, characterized in that: The differential protection system includes a first external clock and a second external clock, wherein the first external clock is used to sync the first differential device, and the second external clock is used to sync the second differential device. The differential protection method further includes: The timing states of the first differential device and the second differential device are monitored in real time, and when it is detected that the timing states of the first differential device and the second differential device are both abnormal, the differential protection is locked.

15. The differential protection method according to claim 1, characterized in that: The differential protection method further comprises: The second differential device sends a second data frame to the first differential device; The second differential device calculates the relative sending time of the second data frame by using the sending time of the second data frame and the current second pulse time; The first differential device calculates the relative reception time of the second data frame using the reception time of the second data frame and the current second pulse time; The first differential device calculates a channel delay using the calculated relative reception time of the second data frame and the relative transmission time of the second data frame calculated by the second differential device; and The first differential device performs differential calculation using the channel delay.

16. A differential protection system, characterized in that: The differential protection system comprises a first differential device, a second differential device, an external clock and a timing unit, wherein: The timing unit is used to synchronize the first differential device and the second differential device using an external clock so that the second pulse moments of the first differential device and the second differential device are absolutely synchronized to determine the current second pulse moment; The first differential device is used to send a first data frame to the second differential device, and calculate the relative sending time of the first data frame by using the sending time of the first data frame and the current second pulse time; The second differential device is used to calculate the relative reception time of the first data frame using the reception time of the first data frame and the current second pulse time, calculate the channel delay using the calculated relative reception time of the first data frame and the relative transmission time of the first data frame calculated by the first differential device, and perform differential calculation using the channel delay.

Images