A method and system for correcting differential current under inconsistent routing based on spatiotemporal data alignment

Abstract

The application provides a correction method and system for differential current under inconsistent transmission path based on space-time data alignment, and belongs to the technical field of data synchronization based on optical fiber communication protection. The method comprises the following steps: acquiring the communication state and switch position of the line on both sides; when the communication on both sides of the line is normal and the switches on both sides of the line are in the closed position, if the current mutation variable does not satisfy the action condition of the current mutation starting element, the opposite-side voltage local estimation value, the opposite-side current local estimation value and the local voltage estimation value of the side are calculated based on the Bergeron model; when the voltage interval constraint is satisfied, it is determined that the transmission path on the side is inconsistent with that on the opposite side; if the transmission path delay difference value calculated exceeds the time threshold value, the correction method is executed, and the corrected differential current is obtained. The method enhances the defense line of the safe and stable operation of the power grid and reduces the misoperation rate of external faults.

Description

Technical Field

[0001] This invention relates to the field of data synchronization technology based on optical fiber communication protection, and more specifically, to a method and system for correcting differential current under channel routing inconsistency based on spatiotemporal data alignment. Background Technology

[0002] Longitudinal differential protection is a widely used main protection function in line protection. Its main function is to calculate the differential current based on the current after synchronization between the two sides. The differential current is small for faults outside the protection zone and large for faults inside the protection zone. The core of differential current calculation lies in "data synchronization". When the data is not synchronized, it will also cause differential current for faults outside the protection zone, which will seriously affect the selectivity of differential protection. The current mainstream data synchronization technology is the "ping-pong time synchronization" technology. This technology assumes that the data transmission routes in the channel are consistent. The data sent by this side is time-stamped. When the other side receives the data, it sends it back along the same route. When this side receives the data, it timestamps it again. The average of the difference between the two timestamps is the channel routing time. When receiving data from the other side, the data on this side compensates for the channel routing time to achieve data synchronization between the two sides.

[0003] To avoid a decrease in the selectivity of differential protection due to inconsistent communication routes, it is necessary to determine the degree of inconsistency in the communication channel routing.

[0004] Existing technical document 1 (CN119209430A) discloses a method and system for longitudinal protection based on time-domain model identification of low-frequency wind power transmission lines. Its drawback is that this method relies on consistent incoming and outgoing routes to ensure synchronized sampling data on both sides. Traditional ping-pong time synchronization methods presuppose consistent incoming and outgoing routes, but in actual engineering, these routes may differ. When the route inconsistency reaches a certain level, differential protection calculations may calculate differential current, potentially misjudging external faults as internal faults, leading to maloperation of the differential protection. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for discriminating inconsistencies in longitudinal transmission channel routing based on spatiotemporal data alignment. It utilizes interpolation between cached data from the Berylon electrical model and real-time sampled data to reflect single-loop routing delay, and combines this with the routing delay on the opposite side to determine the degree of routing difference in incoming loops. Based on the transmission line length, the Berylon electrical model cached data spatially aligns the voltage sample values ​​on both sides to the same time. After receiving the voltage sample value from the opposite side, the local side calculates a vector difference with the previously cached data. The vector difference is then Fourier-calculated to obtain its modulus, which is transmitted to the opposite side through the longitudinal transmission channel. The difference in the modulus of the vector difference between the two sides reflects the routing discrepancy in the channel. This method does not rely on external time synchronization and can monitor the inconsistency status of channel routing in real time during normal system operation.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of the present invention provides a method for correcting differential current under channel routing inconsistency based on spatiotemporal data alignment, comprising the following steps: The communication status and switch position of both sides of the line are obtained. When the communication between both sides of the line is normal and the switches on both sides of the line are in the closed position, if the current change does not meet the operating conditions of the current change initiation element, the local side calculates the local estimated value of the voltage and the local estimated value of the current on the opposite side based on the actual value of the phase voltage on the local side and the Berylon model. The opposite side calculates the local estimated value of the voltage on the local side based on the actual sampled value of the phase voltage on the opposite side and the Berylon model. When the magnitude of the local estimated value of the voltage on the opposite side and the magnitude of the actual sampled value of the phase voltage on the opposite side satisfy the set voltage range constraint, it is determined that the channel routes on this side and the opposite side are inconsistent. Based on the magnitude of the difference between the local estimated value of the voltage on the opposite side and the actual sampled value of the phase voltage on the opposite side, combined with the magnitude of the difference between the local estimated value of the voltage on this side and the actual sampled value of the phase voltage on this side, the channel route delay difference value is calculated. If the channel routing delay difference exceeds the time threshold, correction is performed. The differential current is calculated by using the local estimated value of the opposite current before the corresponding time of the historical channel delay value and the actual value of the phase current on this side, and the corrected differential current is obtained.

[0008] Preferably, the operating conditions for the current-sudden-transition starting element include a first operating condition and a second operating condition; The first action condition is expressed by the following formula:

[0009] In the formula, The maximum value of the half-wave integral of the effective value of each phase current is given by the given value. For floating threshold values, It is a fixed threshold value that can be adjusted; The second action condition is expressed by the following formula:

[0010] in, This represents the maximum value of the half-wave integral of the effective value of the interphase current.

[0011] Preferably, the local estimated value of the counter-side voltage is calculated based on the Berylone model and expressed by the following formula:

[0012] in, This indicates the local estimated value of the voltage on the opposite side. This indicates the local estimated value of the opposite current. Indicates the line voltage transmission coefficient. Indicates transfer impedance, Indicates transfer admittance, Indicates the line current transmission coefficient. This represents the actual value of the phase voltage on this side. This represents the actual value of the phase current on this side.

[0013] Preferably, the line voltage transmission coefficient is expressed by the following formula:

[0014] In the formula, Indicates the line current transmission coefficient. This represents the propagation time delay of a traveling wave as it travels along the line from one side to the other. Phase displacement at time, This indicates the propagation time delay of a traveling wave as it travels along the line from the opposite side to this side. Phase displacement at time, This indicates the total resistance of the line. This represents the characteristic impedance.

[0015] Preferably, the channel routing delay difference value is calculated using the following formula:

[0016] in, This indicates the difference in channel routing delay. This indicates the number of sampling points per cycle. The modulus of the difference between the locally estimated value of the opposite voltage calculated on this side and the actual sampled value of the opposite phase voltage received on this side; The modulus of the difference between the locally estimated value of the local voltage calculated by the other side and the actual sampled value of the local phase voltage received by the other side; The modulus of the actual sampled value of the phase voltage on the opposite side. t represents the time difference between sampling data.

[0017] Preferably, the historical channel delay value is the total channel delay 10ms ago, and the total channel delay... It can be expressed by the following formula:

[0018] in, This indicates the number of sampling points per cycle. The modulus of the difference between the locally estimated value of the opposite-side voltage calculated on this side and the actual sampled value of the opposite-side phase voltage received on this side. The modulus of the actual sampled value of the phase voltage on the opposite side. This represents the time difference between sampling data intervals.

[0019] A second aspect of the present invention provides a differential current correction system based on spatiotemporal data alignment under channel routing inconsistency, which, when running the differential current correction method based on spatiotemporal data alignment under channel routing inconsistency described in the first aspect, includes: The local estimated value calculation module is used to obtain the communication status and switch position on both sides of the line. When the communication on both sides of the line is normal and the switches on both sides of the line are in the closed position, if the current change does not meet the operating conditions of the current change initiation element, the local side calculates the local estimated value of the voltage on the opposite side and the local estimated value of the current on the opposite side based on the actual value of the phase voltage on the local side and the Berylon model; the opposite side calculates the local estimated value of the voltage on the local side based on the actual sampled value of the phase voltage on the opposite side and the Berylon model. The inconsistency determination module is used to determine that the channel routes of this side and the opposite side are inconsistent when the magnitude of the local estimated value of the voltage on the opposite side and the magnitude of the actual sampled value of the phase voltage on the opposite side meet the set voltage range constraints. Based on the magnitude of the difference between the local estimated value of the voltage on the opposite side and the actual sampled value of the phase voltage on the opposite side, and combined with the magnitude of the difference between the local estimated value of the voltage on this side and the actual sampled value of the phase voltage on this side, the channel route delay difference value is calculated. The inconsistency correction module is used to perform correction if the channel routing delay difference exceeds the time threshold value of differential protection. It calculates the differential current by using the local estimated value of the opposite current before the corresponding time of the historical channel delay value and the actual value of the phase current on this side, and obtains the corrected differential current.

[0020] A third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the computer program is loaded onto the processor, it implements a method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment as described in the first aspect.

[0021] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, characterized in that, when executed by a processor, the computer program implements a method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment, as described in any one of the first aspects.

[0022] Compared with the prior art, the beneficial effects of the present invention include at least the following: This invention utilizes the precise physical model of the Berylon line model to calculate the theoretical value of the opposite voltage in real time using local electrical quantities during normal system operation, and compares it with the actual opposite voltage value received through the channel. The deviation between the two directly and accurately reflects the error introduced by channel transmission. This voltage amplitude deviation is quantified as the total channel transmission delay tsum. This mechanism relies only on known line parameters and local sampling data to achieve autonomous, real-time estimation of channel delay, completely eliminating dependence on external clock sources. Through an endogenous synchronization monitoring and correction mechanism that does not rely on external clocks, it reduces the risk of protection maloperation or failure to operate due to external clock failure or channel asymmetry.

[0023] This invention continuously compares and calculates voltage differences while the system is running normally and protection is not activated. When the voltages on both sides are within the normal range, it continuously calculates the channel routing delay difference. This allows the device to monitor and quantify the inconsistency of incoming and outgoing routing in the channel in real time before an external fault occurs. If the inconsistency difference value is abnormal, an early warning can be issued, and the routing delay difference can be displayed externally through a human-machine interface, providing maintenance personnel with a window for proactive intervention. This transforms "passive handling of malfunctions" into "proactive risk prevention," achieving online monitoring and early warning of channel status, giving the device "self-diagnostic" capabilities, supporting condition-based maintenance, and improving the level of intelligent operation and maintenance.

[0024] This invention designs a complete "judgment-correction" closed loop. When the detected difference value exceeds the safety threshold, instead of directly using the real-time calculated delay value, which may be affected by the fault, the cached historical delay value is used for correction. This design cleverly avoids the interference of drastic changes in electrical quantities at the moment of fault initiation on delay estimation, ensuring that the delay value used for correction is a reliable value under stable system conditions. The correction action itself, namely "retrieving the current data before the historical delay value and calculating the difference current with the current on the opposite side", essentially rolls back the local data on the time axis to match the actual sampling time of the data on the opposite side, thereby eliminating synchronization errors at the data source, reducing dependence on high-precision external clock systems, reducing system complexity and construction and maintenance costs, and reducing dependence on and cost of auxiliary equipment.

[0025] Through the aforementioned real-time monitoring and adaptive correction mechanism, this invention can automatically activate correction when the channel inconsistency reaches a dangerous threshold. The differential current obtained after correction removes channel error components to the greatest extent, enabling it to accurately reflect the fault state of the line. This directly prevents false protection tripping caused by false differential currents generated during faults outside the protection zone due to channel routing inconsistencies, significantly improving the selectivity and safety of protection. By accurately identifying and compensating for channel delay differences, it fundamentally solves a large category of potential protection tripping hazards caused by this, strengthens the defense line for the safe and stable operation of the power grid, and reduces the false tripping rate during faults outside the protection zone. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the channel routing inconsistency judgment method provided in accordance with the embodiments of the present invention; Figure 2 This is a schematic diagram of a typical channel delay provided according to an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0028] like Figure 1 As shown, Embodiment 1 of the present invention provides a method for correcting differential current under channel routing inconsistency based on spatiotemporal data alignment, including the following steps: Step 1: Obtain the communication status and switch position on both sides of the line. When the communication on both sides of the line is normal and the switches on both sides of the line are in the closed position.

[0029] Specifically, the operating conditions for the current surge start-up element include a first operating condition and a second operating condition. The protection will start when either operating condition is met.

[0030] The first action condition is expressed by the following formula:

[0031] In the formula, The maximum value among the half-wave integrals of the effective values ​​of the three phase currents. For floating thresholds, A fixed threshold that can be adjusted. Value range: 0.04In~0.5In, with a floating threshold. The current floating threshold changes automatically based on the fluctuations in the load current; that is, the current floating threshold is the magnitude of the load current fluctuation at the previous moment.

[0032] The second action condition is expressed by the following formula:

[0033] in, It is the maximum value among the half-wave integrals of the effective values ​​of the three phase currents.

[0034] This invention requires calculating the actual delay of data transmission to the other side based on the Berylon model. The Berylon algorithm is valid only if the line is intact and there are no breaks in the middle. Therefore, communication between the two sides of the line must be normal and the switches on both sides of the line must be in the closed position. The switches being in the closed position does not necessarily require a load current; it is only necessary to ensure that the systems on both sides are connected. This also conforms to the scenario setting of this invention, which is used for real-time monitoring of the channel routing status of the system to prevent accidental operation from outside the area.

[0035] When calculating channel route inconsistency, the line model must be complete, meaning there cannot be any fault points on the line. Since the line may fail when the protection starts, route inconsistency calculation is not performed when the protection starts.

[0036] Step 2: If the current surge does not meet the operating conditions of the current surge initiation element, the local estimated value of the voltage on the opposite side is calculated based on the actual value of the phase voltage on this side and the Berylon model; the local estimated value of the voltage on the opposite side is calculated based on the actual sampled value of the phase voltage on the opposite side and the Berylon model.

[0037] The local estimated value of the voltage on the opposite side is calculated based on the Berylon model. The Berylon model is used to represent the relationship between the local estimated value of the voltage on the opposite side and the phase current and the actual sampled phase voltage and phase current on the local side, as expressed by the following formula:

[0038] in, This indicates the local estimated value of the voltage on the opposite side. The local estimated value of the voltage on the opposite side is the same as the local estimated value of the voltage on the opposite side. This indicates the local estimated value of the opposite current. This indicates the actual phase voltage collected on this side. This indicates the actual phase current collected on this side. The line voltage transmission coefficient is expressed by the following formula:

[0039] In the formula, A represents the line voltage transmission coefficient. Indicates the line current transmission coefficient. This represents the propagation time delay of a traveling wave as it travels along the line from one side to the other. Phase displacement at time, This indicates the propagation time delay of a traveling wave as it travels along the line from the opposite side to this side. The phase displacement at time satisfies , The total resistance of the line is expressed by the following formula:

[0040] In the formula, The resistance per unit length of the line. Indicates the total length of the line. The time delay of a traveling wave from one side of a line to the other is expressed by the following formula:

[0041] In the formula, Inductance per unit length Capacitance per unit length This represents the traveling wave transmission speed.

[0042] Characteristic impedance is expressed by the following formula:

[0043] The transfer impedance is expressed by the following formula:

[0044] The transfer admittance is expressed by the following formula:

[0045] The Berylon model transforms a lossy transmission line into a lossless transmission line by dividing a uniform lossy transmission line into two segments of equal length, with the resistance parameters of each segment concentrated at both ends of the line.

[0046] Step 3: Calculate the local estimated value of the voltage on the opposite side. Compared with the actual sampled value of the phase voltage on the opposite side The difference The difference is calculated using the Fourier algorithm. modulus Local estimated value of the opposite side voltage modulus Actual sampled value of phase voltage on the opposite side modulus At the same time, the modulus Send to the other side of the line.

[0047] Step 4: When the magnitude of the local estimated value of the voltage on the opposite side and the magnitude of the actual sampled value of the phase voltage on the opposite side satisfy the set voltage range constraint, it is determined that the channel routes on this side and the opposite side are inconsistent. Based on the magnitude of the difference between the local estimated value of the voltage on the opposite side and the actual sampled value of the phase voltage on the opposite side, combined with the magnitude of the difference between the local estimated value of the voltage on this side calculated by the opposite side and the actual sampled value of the phase voltage on this side received by the opposite side, the channel route delay difference value is calculated. When either the magnitude of the local estimated value of the voltage on the opposite side or the magnitude of the actual sampled value of the phase voltage on the opposite side does not satisfy the set voltage range constraint, the process returns to step 1.

[0048] Specifically, the voltage deviation will not exceed 10% of the rated voltage during normal system operation, and the voltage range constraint is set within the range of 0.9 to 1.1 times the rated voltage Un.

[0049] Specifically, the channel routing delay difference is calculated using the following formula:

[0050] in, This indicates the difference in channel routing delay. This indicates the number of sampling points per cycle. , The modulus of the difference between the locally estimated value of the opposite-side voltage calculated on this side and the actual sampled value of the opposite-side phase voltage received on this side; The modulus of the difference between the locally estimated value of the local voltage calculated by the counterpart and the actual sampled value of the local phase voltage received by the counterpart is expressed by the following formula:

[0051] In the formula, This represents the actual sampled value of the phase voltage on this side. The estimated local voltage value is expressed by the following formula:

[0052] In the formula, This indicates the local estimated value of the current on this side. This represents the actual value of the phase voltage on the opposite side. This represents the actual value of the phase current on the opposite side. t is the time difference between sampling data. t = number of sampling points per cycle N / sampling cycle time. Generally, the number of sampling points N per cycle is 24, and the sampling cycle time is 20ms.

[0053] Inconsistent routing is one of the causes of differential protection malfunctions. If routing inconsistencies can be identified, differential protection can be immediately blocked to prevent malfunctions. Traditional protection relies on external clocks such as GPS and BeiDou to time-stamp data, or assumes symmetrical bidirectional time delays in the channel. The formula for the channel routing time delay difference abandons these assumptions, utilizing only the electrical quantities (voltage amplitude deviation) that can be obtained in real time on both sides of the line. Through mathematical transformation (arcsin function), the voltage difference is mapped to a phase difference, and then combined with the sampling data interval time difference to convert it into a time difference, quantifying the degree of channel asymmetry and providing a direct and objective numerical basis for determining whether to initiate correction. |D(t)| and |DR(t)| are continuously calculated and exchanged on the local and opposite sides when the system is running normally and the protection is not activated. Through real-time calculation and judgment of C... The value enables the system to identify the potential problem of "inconsistent routing of incoming and outgoing channels" before a fault occurs outside the zone, realizing the transformation from "passive malfunction after a fault" to "proactive early warning and defense before a fault occurs," allowing the system to issue an alarm or prepare for correction before the risk accumulates to a dangerous level.

[0054] Through calculation Essentially, it compares the estimated transmission delay values ​​for two opposite communication directions, and the result C The value directly and uniquely reflects the asymmetry of the channel, rather than a general channel interruption or quality degradation. This allows the protection device to accurately distinguish between |D(t)| and |DR(t)|, which are both large but close, and C. Small values ​​indicate symmetrical channels but poor quality, potentially requiring no correction; |D(t)| and |DR(t)| differ significantly, C If the value is large, the channel routing is inconsistent and must be corrected to prevent accidental operation. This accurate diagnosis avoids unnecessary correction operations and ensures timely intervention in truly risky scenarios.

[0055] By calculating the channel routing delay difference, the core hidden danger of "routing inconsistency" that leads to maloperation outside the zone can be detected and warned in advance, and intelligent synchronous correction can be triggered, thereby significantly reducing the risk of differential protection maloperation due to channel problems and improving the reliability of power grid safe operation.

[0056] This invention determines that the local and opposite channel routes are inconsistent when both the magnitude of the local estimated value of the opposite voltage and the magnitude of the actual sampled value of the opposite phase voltage are within the set rated voltage range. It judges that the voltage is normal as an important indicator of whether the transmission line is normal. Only when the transmission line is normal is the Berylon model complete and this discrimination method effective.

[0057] Step 5: If the channel routing delay difference exceeds the time threshold of the differential protection, then perform correction. Calculate the differential current using the local estimated value of the opposite current before the corresponding time of the historical channel delay value and the actual value of the phase current on this side, and obtain the corrected differential current.

[0058] The receiving channel delay tsum is calculated in real time, and the historical delay value t from 10ms ago is buffered. sum, determine the channel routing delay difference value C. Does it exceed the time threshold value of differential protection? When C is satisfied ≥ At that time, the local estimated value of the voltage on the opposite side calculated from this side. Local estimated value of the opposite side current In the middle, take out t Locally estimated value of the opposite current before time sum ,use Compared with the actual phase current collected on this side Perform differential current calculation. The result of the differential current calculation is used as the final criterion for longitudinal differential protection to determine with extremely high reliability whether an internal fault has occurred in the protected line, and to drive the circuit breaker to trip and isolate the fault.

[0059] Total delay of receiving channel It can be expressed by the following formula:

[0060] in, This represents the time threshold value for differential protection, used to describe the maloperation setting of differential protection caused by the degree of inconsistency in channel routing. A typical value is [value missing]. .

[0061] Among them, tsum is composed of line delay t1 and channel transmission delay tdey (i.e., tsum = t1 + tdey), which is used to characterize the complete channel delay from the other side to the local side. The t'sum value before 10ms is used to avoid the calculation fluctuation caused by the sensitive response of the starting element in the initial stage of the fault, and to ensure that the delay value used truly reflects the steady-state channel characteristics.

[0062] Because the tsum calculated after startup cannot accurately reflect the channel delay, and considering that the startup element is generally very sensitive and can start under any fault, but the protection also has a certain delay in judging startup, generally 1~3ms, the present invention takes 10ms to ensure that the calculated tsum is the value when no system fault has occurred.

[0063] Figure 2 The local data a, e, p, and q on side M are the sampled data of this side. Z', A', O', and P' are the values ​​calculated based on the local data a, e, p, and q using the Berylon model. Among them, the buffered data A' on side M and the sampled data A on side N are spatially equivalent to the same sampled value. The data e on side M and the data A on side N are sampled values ​​at the same time. The buffered data A' on side M and the sampled value of data a are the same. The sampled value A on side N is sent from side N after a delay t1 and sent to side M after a channel delay tdey. When side M receives data A from side N, the buffered data is p'. p' is the same as the sampled value of the local data p on side M. Therefore, the time difference between the sampled data p and a is tsum = tdey + t1. tsum reflects the channel delay time of data A being sent from side N to side M.

[0064] This invention uses the line Berylon model to transform the line / bus voltage and current spatially distributed in two different substations into the voltage and current of the same substation. Using the received voltage and current sampling values ​​from the other side as a reference time, the receiving channel delay is calculated using the voltage sampling values ​​from the same substation. Through receiving channel delay compensation, the current sampling values ​​on both sides of the line for differential protection calculation are obtained, thus solving the problem of increased differential current calculation error and maloperation of differential protection caused by inconsistent channel incoming and outgoing routes.

[0065] Embodiment 2 of the present invention provides a differential current correction system for channel routing inconsistency based on spatiotemporal data alignment, and implements the differential current correction method for channel routing inconsistency based on spatiotemporal data alignment described in Embodiment 1, including: The local estimated value calculation module is used to obtain the communication status and switch position on both sides of the line. When the communication on both sides of the line is normal and the switches on both sides of the line are in the closed position, if the current change does not meet the operating conditions of the current change initiation element, the local side calculates the local estimated value of the voltage on the opposite side and the local estimated value of the current on the opposite side based on the actual value of the phase voltage on the local side and the Berylon model; the opposite side calculates the local estimated value of the voltage on the local side based on the actual sampled value of the phase voltage on the opposite side and the Berylon model. The inconsistency determination module is used to determine that the channel routes of this side and the opposite side are inconsistent when the magnitude of the local estimated value of the voltage on the opposite side and the magnitude of the actual sampled value of the phase voltage on the opposite side meet the set voltage range constraints. Based on the magnitude of the difference between the local estimated value of the voltage on the opposite side and the actual sampled value of the phase voltage on the opposite side, and combined with the magnitude of the difference between the local estimated value of the voltage on this side and the actual sampled value of the phase voltage on this side, the channel route delay difference value is calculated. The inconsistency correction module is used to perform correction if the channel routing delay difference exceeds the time threshold value of differential protection. It calculates the differential current by using the local estimated value of the opposite current before the corresponding time of the historical channel delay value and the actual value of the phase current on this side, and obtains the corrected differential current.

[0066] Embodiment 3 of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded onto the processor, it implements a method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment as described in Embodiment 1.

[0067] Embodiment 4 of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment as described in Embodiment 1.

[0068] Compared with the prior art, the beneficial effects of the present invention include at least the following: This invention relies solely on existing line parameters and sampling data, without requiring external time synchronization markers, to accurately determine the delay time of data transmission from the other side. This enables real-time monitoring of channel routing differences and resolves the problem of differential protection maloperation caused by inconsistent channel routing. When the channel routing is inconsistent, the abnormal state can be accurately identified. Both the local and the other side correct the received synchronization data based on the calculated actual receiving route delay. The proposed channel routing inconsistency detection method can detect channel inconsistency before external faults occur. The problem of external maloperation can be solved by compensating for channel inconsistency differences and correcting the synchronization data on both sides. When the switches on both sides of the line are in the closed position, the device can monitor the inconsistency status of the longitudinal channel routing in real time and display it externally through the incoming route delay difference. When the channel routing inconsistency exceeds a threshold, the received current sampling value is corrected based on the calculated receiving route delay to prevent external disturbances from causing differential protection maloperation.

[0069] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment, wherein both sides of the line include the local side and the opposite side, characterized in that, include: The communication status and switch position of both sides of the line are obtained. When the communication between both sides of the line is normal and the switches on both sides of the line are in the closed position, if the current change does not meet the operating conditions of the current change initiation element, the local side calculates the local estimated value of the voltage and the local estimated value of the current on the opposite side based on the actual value of the phase voltage on the local side and the Berylon model. The opposite side calculates the local estimated value of the voltage on the local side based on the actual sampled value of the phase voltage on the opposite side and the Berylon model. When the magnitude of the locally estimated voltage on the opposite side and the magnitude of the actual sampled phase voltage on the opposite side satisfy the set voltage range constraint, it is determined that the channel routes on this side and the opposite side are inconsistent. Based on the magnitude of the difference between the locally estimated voltage on the opposite side and the actual sampled phase voltage on the opposite side, combined with the magnitude of the difference between the locally estimated voltage on this side and the actual sampled phase voltage on this side, the channel route delay difference is calculated, expressed by the following formula: in, This indicates the difference in channel routing delay. This indicates the number of sampling points per cycle. The modulus of the difference between the locally estimated value of the opposite voltage calculated on this side and the actual sampled value of the opposite phase voltage received on this side; The modulus of the difference between the locally estimated value of the local voltage calculated by the other side and the actual sampled value of the local phase voltage received by the other side; The modulus of the actual sampled value of the phase voltage on the opposite side. t represents the time difference between sampling data intervals; If the channel routing delay difference exceeds the time threshold of the differential protection, correction is performed. The differential current is calculated by using the local estimated value of the opposite current before the corresponding time of the historical channel delay value and the actual value of the phase current on this side, and the corrected differential current is obtained.

2. The method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment according to claim 1, characterized in that: The operating conditions for a current-sudden-start element include a first operating condition and a second operating condition; The first action condition is expressed by the following formula: In the formula, The maximum value of the half-wave integral of the effective value of each phase current is given by the given value. For floating threshold values, It is a fixed threshold value that can be adjusted; The second action condition is expressed by the following formula: in, This represents the maximum value of the half-wave integral of the effective value of the interphase current.

3. The method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment according to claim 1, characterized in that: The estimated local values ​​of the opposite-side voltage and opposite-side current are calculated based on the Berylon model and expressed by the following formulas: in, This indicates the local estimated value of the voltage on the opposite side. This indicates the local estimated value of the opposite current. Indicates the line voltage transmission coefficient. Indicates transfer impedance, Indicates transfer admittance, Indicates the line current transmission coefficient. This represents the actual value of the phase voltage on this side. This represents the actual value of the phase current on this side.

4. The method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment according to claim 3, characterized in that: The estimated local voltage value is calculated based on the Berylone model and expressed by the following formula: In the formula, This indicates the local estimated value of the voltage on this side. This indicates the local estimated value of the current on this side. This represents the actual value of the phase voltage on the opposite side. This represents the actual value of the phase current on the opposite side.

5. The method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment according to claim 4, characterized in that: The line voltage transmission coefficient is expressed by the following formula: In the formula, Indicates the line current transmission coefficient. This represents the propagation time delay of a traveling wave as it travels along the line from one side to the other. Phase displacement at time, This indicates the propagation time delay of a traveling wave as it travels along the line from the opposite side to this side. Phase displacement at time, This indicates the total resistance of the line. This represents the characteristic impedance.

6. The method for correcting differential current under channel routing inconsistency based on spatiotemporal data alignment according to claim 1, characterized in that: The historical channel delay value is the total channel delay 10ms ago. It can be expressed by the following formula: in, This indicates the number of sampling points per cycle. The modulus of the difference between the locally estimated value of the opposite-side voltage calculated on this side and the actual sampled value of the opposite-side phase voltage received on this side. The modulus of the actual sampled value of the phase voltage on the opposite side. This represents the time difference between sampling data intervals.

7. A system for correcting differential current under channel routing inconsistency based on spatiotemporal data alignment, comprising the method for correcting differential current under channel routing inconsistency based on spatiotemporal data alignment as described in any one of claims 1-6, characterized in that: The local estimated value calculation module is used to obtain the communication status and switch position on both sides of the line. When the communication on both sides of the line is normal and the switches on both sides of the line are in the closed position, if the current change does not meet the operating conditions of the current change initiation element, the local side calculates the local estimated value of the voltage on the opposite side and the local estimated value of the current on the opposite side based on the actual value of the phase voltage on the local side and the Berylon model; the opposite side calculates the local estimated value of the voltage on the local side based on the actual sampled value of the phase voltage on the opposite side and the Berylon model. The inconsistency determination module is used to determine that the channel routes of this side and the opposite side are inconsistent when the magnitude of the local estimated value of the voltage on the opposite side and the magnitude of the actual sampled value of the phase voltage on the opposite side meet the set voltage range constraints. Based on the magnitude of the difference between the local estimated value of the voltage on the opposite side and the actual sampled value of the phase voltage on the opposite side, and combined with the magnitude of the difference between the local estimated value of the voltage on this side and the actual sampled value of the phase voltage on this side, the channel route delay difference value is calculated. The inconsistency correction module is used to perform correction if the channel routing delay difference exceeds the time threshold. It calculates the differential current by using the local estimated value of the opposite current before the corresponding time of the historical channel delay value and the actual value of the phase current on this side, and obtains the corrected differential current.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is loaded into the processor, it implements a method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment, according to any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a method for correcting differential current under inconsistent channel routing based on spatiotemporal data alignment, according to any one of claims 1-6.

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