A method, apparatus, and medium for identifying a relay protection terminal loop exception

Abstract

The application discloses a kind of relay protection terminal loop abnormality identification method, equipment and medium, comprising: obtaining the line three-phase current value of target distribution station and its adjacent distribution station;Based on line three-phase current value, line differential current and bus differential current are calculated respectively;Based on line differential current, bus differential current and line three-phase current value, determine whether the secondary loop of target distribution station is CT broken line abnormality;The three-phase voltage of bus voltage of target distribution station is first bus three-phase voltage, the three-phase voltage of bus voltage of target distribution station's incoming line interval opposite side distribution station is second bus three-phase voltage, and line voltage difference is calculated;Based on line voltage difference and line three-phase current value, determine whether the secondary loop of target distribution station is PT broken line abnormality.The application effectively utilizes the characteristics of communication, accurately judges the loop abnormality such as CT, PT broken line, the criterion needs to collect less electrical quantity, reliability is high, alleviate the existing problems of relay protection terminal loop abnormality identification difficulty in prior art.

Description

Technical Field

[0001] This invention relates to the field of power system protection and control technology, specifically to a method, device, and medium for identifying abnormalities in relay protection terminal circuits. Background Technology

[0002] Current transformers (CTs) and voltage transformers (PTs) are crucial components for ensuring the safe and stable operation of power systems. When the secondary side of a CT is open-circuited, it not only endangers equipment safety but also easily leads to incorrect protection operation. Therefore, accurately identifying CT open circuits is vital for equipment operation and maintenance and the reliability of protection systems. To avoid maloperation of protection systems in the event of a CT open circuit, most engineering projects currently use CT open circuit blocking criteria to block the corresponding protection. This approach is beneficial for improving the reliability of high-voltage protection systems with dual configurations, but for distribution network protection systems with single configurations, a CT open circuit will cause the protection to deactivate. A PT open circuit will affect functions such as reverse voltage directional elements, first switch undervoltage tripping, rapid self-healing, and automatic transfer switching, resulting in protection failure or maloperation. In summary, the technical challenge of identifying abnormalities in relay protection terminal circuits remains a significant issue for distribution network protection. Summary of the Invention

[0003] The purpose of this invention is to provide a method, device, and medium for identifying abnormalities in relay protection terminal circuits in order to solve at least one of the above-mentioned technical problems.

[0004] In a first aspect, embodiments of the present invention provide a method for identifying abnormal circuits in relay protection terminals, applied to relay protection terminals of a target substation; the target substation is one of a plurality of substations between two substations; the relay protection terminals of adjacent substations communicate with each other; the method includes: acquiring the three-phase current values ​​of the lines in the target substation; the three-phase current values ​​include: the three-phase current of the incoming line bay, the three-phase current of the feeder bay, and the three-phase current of the switch of the substation opposite to the incoming line bay; calculating the line differential current and the bus differential current based on the line differential current values; and calculating the line differential current, the bus differential current, and the... The three-phase current value of the line is used to determine whether the secondary circuit of the target substation is abnormally disconnected by a CT; the three-phase bus voltage of the target substation is obtained as the first bus three-phase voltage, and the three-phase bus voltage of the substation opposite the incoming line bay of the target substation is obtained as the second bus three-phase voltage; if the switch positions of the incoming line bay switch and the switch of the substation opposite the incoming line bay of the target substation are both in the closed position, the line voltage difference is calculated based on the first bus three-phase voltage and the second bus three-phase voltage; based on the line voltage difference and the three-phase current value of the line, it is determined whether the secondary circuit of the target substation is abnormally disconnected by a PT.

[0005] Further, based on the three-phase current values ​​of the line, the line differential current and the bus differential current are calculated respectively, including: calculating the line differential current using the following formula: The bus differential current is calculated using the following formula: Among them, I DL For the differential current of the line, I DB For the bus differential current, The three-phase current of the incoming line bay is given. The three-phase current of the feeder interval is given. The three-phase current is the switch of the substation on the opposite side of the incoming line bay.

[0006] Furthermore, the CT disconnection anomaly includes incoming line bay CT disconnection anomaly and feeder bay CT disconnection anomaly; based on the line differential current, the bus differential current, and the line three-phase current values, determining whether the secondary circuit of the target substation has a CT disconnection anomaly includes: judging whether the following conditions are met: If so, then the secondary circuit incoming line bay CT of the target substation is determined to be abnormally disconnected; determine whether the following conditions are met: If so, then the secondary circuit feeder bay CT of the target substation is determined to be abnormally disconnected; where, I set1 I is the phase overcurrent threshold. set2 I is the line differential current threshold. set3 This is the bus differential current threshold.

[0007] Further, calculating the line voltage difference based on the three-phase voltage of the first bus and the three-phase voltage of the second bus includes: calculating the line voltage difference using the following formula: Wherein, ΔU is the line voltage difference. Let be the vector value of the three-phase voltage of the first busbar. This represents the vector value of the three-phase voltage of the second bus.

[0008] Furthermore, based on the line voltage difference and the three-phase current value of the line, determining whether the secondary circuit of the target substation is abnormally disconnected by a PT includes: judging whether the following conditions are met: If so, then the secondary circuit PT of the target substation is determined to be abnormally disconnected; where, I set1 U is the phase overcurrent threshold. n The rated voltage at which the target substation operates. The three-phase current values ​​of the line are given.

[0009] Furthermore, it also includes: if the following conditions are met, the CT identification function of the target substation is locked: communication is interrupted, and the collected AC quantity and fault information are not transmitted to the opposite substation; at least one phase current in one interval is greater than a preset threshold; if the following conditions are met, the PT identification function of the target substation is locked: communication is interrupted, and the collected AC quantity and fault information are not transmitted to the opposite substation; at least one phase current in one interval is greater than the preset threshold; all incoming switches of the target substation are in the open position.

[0010] Secondly, embodiments of the present invention also provide a method for identifying abnormal relay protection terminal circuits, applied to the relay protection terminal of a target main line switch; the target main line switch is a switch among multiple main line switches on an overhead main line; multiple branch feeders exist between the multiple main line switches; the method includes: acquiring the target three-phase current of the target main line switch, the upstream three-phase current of the target main line switch, and the downstream three-phase current of the target main line switch; the upstream three-phase current includes the three-phase current of the upstream adjacent main line switch of the target main line switch and the three-phase current of the target main line switch and the three-phase current of the target main line switch. The three-phase currents of multiple branch feeders between upstream adjacent main line switches; the downstream three-phase currents include the three-phase currents of downstream adjacent main line switches of the target main line switch and the three-phase currents of multiple branch feeders between the target main line switch and the downstream adjacent main line switch; based on the target three-phase current, the upstream three-phase current and the downstream three-phase current, calculate the upstream differential current and the downstream differential current; based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential current and the downstream differential current, determine whether the secondary circuit of the switch bay of the target main line switch is abnormally disconnected by the CT.

[0011] Furthermore, based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential current, and the downstream differential current, it is determined whether the secondary circuit of the switch bay of the target main line switch is abnormally disconnected, including: determining whether the following conditions are met: If so, then the secondary circuit CT of the target main line switch is determined to be abnormally disconnected; determine whether the following conditions are met: If so, it is determined that there is a CT disconnection anomaly in the secondary circuit of the branch feeder switch between the target main line switch and the upstream adjacent main line switch, and the CT disconnection interval is the k-th feeder interval; where, The target three-phase current, The three-phase current of the upstream adjacent main line switch is... I represents the three-phase current of the multiple branch feeders between the target main line switch and the downstream adjacent main line switch. D1For the upstream differential current, I D2 For the downstream differential current, I setM I is the phase overcurrent threshold of the target main line switch. setN I is the phase overcurrent threshold of the upstream adjacent main line switch. set4 I represents the overcurrent threshold of each upstream branch feeder phase of the target main line switch. set5 I is the differential current threshold of the upstream section. set6 I is the differential current threshold for the downstream section. set7 The threshold value for no current in the switching interval.

[0012] Thirdly, embodiments of the present invention also provide an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the methods described in the first and second aspects.

[0013] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the methods described in the first and second aspects.

[0014] This invention provides a method, device, and medium for identifying abnormal circuits in relay protection terminals. It effectively utilizes the characteristics of communication to accurately determine abnormal circuits such as CT and PT disconnections. The criteria require less electrical quantity data collection and have high reliability, thus alleviating the technical problem of difficulty in identifying abnormal circuits in relay protection terminals in the prior art. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 A flowchart of a relay protection terminal circuit anomaly identification method provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of a cable transmission line system provided in an embodiment of the present invention;

[0018] Figure 3 A flowchart of another relay protection terminal circuit anomaly identification method provided in an embodiment of the present invention;

[0019] Figure 4This is a schematic diagram of an overhead power transmission line system provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1

[0022] Figure 1 This is a flowchart of a relay protection terminal circuit anomaly identification method provided by an embodiment of the present invention, which is applied to the relay protection terminal of the target substation. Figure 2 This is a schematic diagram of a cable transmission line system according to an embodiment of the present invention.

[0023] like Figure 2 As shown, there are multiple distribution substations interconnected between substation A and substation B. Each distribution substation is equipped with a relay protection terminal, which has data acquisition, communication, phase overcurrent protection, line differential, bus differential, and CT disconnection identification functions. The target distribution substation is one of the multiple distribution substations between the two substations (substation A and substation B). The relay protection terminals of adjacent distribution substations communicate with each other.

[0024] like Figure 1 As shown, the method provided in this embodiment of the invention specifically includes the following steps:

[0025] Step S102: Obtain the three-phase current values ​​of the target substation line; the three-phase current values ​​of the line include: the three-phase current of the incoming line bay, the three-phase current of the feeder bay, and the three-phase current of the switch of the substation opposite the incoming line bay.

[0026] Specifically, such as Figure 2 As shown, the relay protection terminal collects the three-phase currents of the incoming line bays M1 and M2 of the substation. And the remaining feeder spacing M3...MX three-phase current The three-phase current of the switch at the opposite side of the incoming line bay M1 is obtained through communication. The three-phase current of the substation switch opposite to the incoming line bay M2 If communication is interrupted, station M (i.e., the target substation) will be unable to collect the AC data. Transmitted to N stations or failed to collect the communication volume If the data is transmitted to station K, the target substation's CT identification function will be locked; if the AC data of station N on the opposite side cannot be obtained... Then the CT recognition function of station N on the opposite side is locked; the same applies to station K.

[0027] Stations M, N, and K are based on the fact that the collected current is less than their respective phase overcurrent setting I. set1 No phase overcurrent was detected at any station; otherwise, the CT disconnection detection function would be blocked if the phase overcurrent exceeded the limit.

[0028] Step S104: Calculate the line differential current and bus differential current based on the three-phase current values ​​of the line.

[0029] Specifically, the line differential current is calculated using the following formula:

[0030]

[0031] Calculate the bus differential current using the following formula:

[0032]

[0033] Among them, I DL For line differential current; I DB The bus differential current is the change in differential current, which is equal to the absolute value of the sum of the current changes of each connected unit. The three-phase current of the incoming line bay. The three-phase current of the feeder interval. This refers to the three-phase current of the switch on the opposite side of the incoming line bay.

[0034] Step S106: Based on the line differential current, bus differential current and line three-phase current values, determine whether the secondary circuit of the target substation is abnormally disconnected by the CT.

[0035] Specifically, in this embodiment of the invention, CT disconnection anomaly includes incoming line bay CT disconnection anomaly and feeder bay CT disconnection anomaly; determining whether the secondary circuit of the target substation has a CT disconnection anomaly based on the line differential current, bus differential current, and line three-phase current values ​​includes:

[0036] Determine whether the following conditions are true:

[0037]

[0038] If so, then the secondary circuit incoming line bay CT of the target substation is determined to be abnormally disconnected.

[0039] In this embodiment of the invention, after determining that the incoming line bay CT is abnormally disconnected, the current of the switch on the opposite side interconnected with it is used as the disconnected bay current to participate in the bus differential protection calculation, that is... The methods for determining and handling CT line breaks in the M2 interval are the same as those for the M1 interval.

[0040] Determine whether the following conditions are true:

[0041]

[0042] If so, then the secondary circuit feeder bay CT disconnection in the target substation is determined to be abnormal; where, I set1 Iset1 is the phase overcurrent threshold, Iset2 is the line differential current threshold, and Iset3 is the bus differential current threshold.

[0043] In this embodiment of the invention, after determining that the feeder bay CT is abnormally disconnected, the combined current of other bays in the target substation is used as the disconnected bay current to participate in the line protection calculation, and the disconnected bay current I... H The phase is opposite to the current of the switch on the opposite side it is interconnected with.

[0044] Specifically, (X≠Broken line interval).

[0045] Step S108: Obtain the three-phase bus voltage of the target substation as the first bus voltage, and obtain the three-phase bus voltage of the substation opposite the incoming line bay of the target substation as the second bus voltage.

[0046] Specifically, such as Figure 2 As shown, the three-phase voltage U of the first busbar of the target substation is collected. M1 The switch B in the input bay M1 is collected. M1 Switch B in incoming line bay M2 M2 The location status is obtained through communication, and the three-phase voltage U of the second busbar of the station opposite to bay M1 is acquired. N1 and switch B N1 Location status, three-phase voltage U of the station on the opposite side of M2 K1 and switch B K1 Position status;

[0047] Each substation collects the three-phase voltage U of the first busbar of the target substation. M1 Outgoing switch K M1 The location was determined through communication, and the three-phase voltage U of the second busbar of the opposite station switch was obtained. N1 and incoming line switch K N2 The location.

[0048] Step S110: If the switch positions of the incoming line bay switch of the target substation and the switch of the substation opposite the incoming line bay of the target substation are both in the closed position, then the line voltage difference is calculated based on the three-phase voltage of the first bus and the three-phase voltage of the second bus.

[0049] Specifically, the line voltage difference is calculated using the following formula:

[0050]

[0051] Where ΔU is the line voltage difference, This represents the vector value of the three-phase voltage of the first busbar. This represents the vector value of the three-phase voltage of the second bus.

[0052] Step S112: Based on the line voltage difference and the three-phase current value of the line, determine whether the secondary circuit of the target substation is abnormally disconnected by the PT.

[0053] Specifically, determine whether the following conditions are true:

[0054]

[0055] If so, then the secondary circuit PT of the target substation is determined to be abnormally disconnected;

[0056] Among them, I set1 Where Un is the phase overcurrent threshold, and Un is the rated voltage of the target substation during operation. These are the three-phase current values ​​of the line.

[0057] In this embodiment of the invention, after determining that the PT of the target substation is disconnected, the voltage of the adjacent interconnected substations is used as the voltage of the target substation to participate in the line protection calculation.

[0058] Optionally, in an embodiment of the present invention, I set1 I set2 I set3 The specific values ​​are determined based on the line parameters.

[0059] Optionally, in this embodiment of the invention, the CT identification function of the target substation is blocked if the following conditions are met: communication is interrupted, and the collected AC quantity and fault information are not transmitted to the opposite substation; at least one phase current in the interval is greater than a preset threshold.

[0060] The PT identification function of the target substation will be blocked if the following conditions are met: communication is interrupted, and the collected AC quantity and fault information are not transmitted to the opposite substation; at least one phase current in the interval is greater than the preset threshold; and all incoming switches of the target substation are in the open position.

[0061] It should be noted that, in this embodiment of the invention, the condition for the differential pressure calculation to be valid is that the incoming line switch of the target substation and the switch on the opposite side of the incoming line bay are both in the closed position. Then, the voltage difference between the target substation voltage and the voltage of the opposite substation is calculated.

[0062] This invention provides a method for identifying abnormal relay protection terminal circuits. Through communication between the local and adjacent substations, it calculates the line current differential and simultaneously calculates the bus current differential of the local substation to identify CT (current transformer) disconnections, ensuring accurate CT disconnection identification. After identifying a CT disconnection, the current of the switch bay of the adjacent substation is used to replace the CT disconnection voltage, or the combined current of other bays in the local substation is used to replace the CT disconnection voltage in the protection calculation. For single-set distribution network protection, the protection will not trip. Furthermore, the PT (potential transformer) identification accuracy is high, solving the problem of difficult three-phase PT disconnection (circuit breaker tripping) detection under light load conditions. After identifying a PT disconnection, the voltage of the adjacent substation is used to replace the disconnection voltage in the protection calculation, ensuring the protection does not trip.

[0063] Example 2

[0064] Figure 3 This is a flowchart of another method for identifying abnormal circuits in a relay protection terminal according to an embodiment of the present invention. This method is applied to the relay protection terminal of a target main line switch. Figure 4 This is a schematic diagram of an overhead power transmission line system provided according to an embodiment of the present invention.

[0065] like Figure 4 As shown, there are multiple switches on the main line between substation A and substation B. The target main line switch is one of the multiple main line switches on the overhead line. There are multiple branch feeders between the multiple main line switches. Each main line switch is equipped with a relay protection terminal. The relay protection terminal has functions such as data acquisition, communication, phase overcurrent protection, line differential protection, and CT disconnection identification. The two relay protection terminals can communicate with each other.

[0066] like Figure 3 As shown, the method provided in this embodiment of the invention specifically includes the following steps:

[0067] Step S302: Obtain the target three-phase current of the target main line switch, the upstream three-phase current of the target main line switch, and the downstream three-phase current of the target main line switch.

[0068] The upstream three-phase current includes the three-phase current of the upstream adjacent main line switch of the target main line switch and the three-phase current of multiple branch feeders between the target main line switch and the upstream adjacent main line switch; the downstream three-phase current includes the three-phase current of the downstream adjacent main line switch of the target main line switch and the three-phase current of multiple branch feeders between the target main line switch and the downstream adjacent main line switch.

[0069] Specifically, such as Figure 4 As shown, the relay protection terminal collects the target three-phase current of the target main line switch M. Furthermore, the three-phase current of the upstream adjacent main line switch is collected via communication. The three-phase current of multiple branch feeders between the target main line switch and the upstream adjacent main line switch. And to collect the three-phase current of downstream adjacent main line switches via communication. The three-phase current of multiple branch feeders between the target main line switch and the downstream adjacent main line switch.

[0070] Step S304: Calculate the upstream differential current and the downstream differential current based on the target three-phase current, the upstream three-phase current, and the downstream three-phase current.

[0071] Specifically, the upstream differential current is calculated using the collected current.

[0072] Calculate downstream differential current

[0073] Step S306: Based on the target three-phase current, upstream three-phase current, downstream three-phase current, upstream differential current, and downstream differential current, determine whether the secondary circuit of the switch bay of the target main line switch is abnormally disconnected by the CT.

[0074] Specifically, determine whether the following conditions are true:

[0075]

[0076] If so, then the secondary circuit CT of the target main line switch is determined to be abnormally disconnected.

[0077] In this embodiment of the invention, if it is determined that the main line switch CT is abnormally disconnected, the current of other switches in the upstream section or the current of other switches in the downstream section of switch M (i.e., the target main line switch) is used as the current of the disconnected switch to participate in the line protection calculation.

[0078] Specifically, when the main line switch CT disconnects, the combined current of other intervals in the upstream section of switch M is used as the disconnection current, and its value is... (X ≠ Disconnection Switch); The sum of the currents of other intervals downstream of switch M is used, and its value is... (X≠ disconnection switch).

[0079] Determine whether the following conditions are true:

[0080]

[0081] If so, it is determined that there is a CT disconnection anomaly in the secondary circuit of the branch feeder switch between the target main line switch and the upstream adjacent main line switch, and the CT disconnection interval is the kth feeder interval.

[0082] In this embodiment of the invention, if it is determined that the branch line switch CT is abnormally disconnected, the current of all switches in the upstream section of switch M is used as the current of the disconnected switch to participate in the line protection calculation.

[0083] Specifically, the current of the switch upstream of switch M is used as the current of the disconnect switch, and the value of the disconnect switch current is... (X≠ disconnection switch).

[0084] in, For the target three-phase current, This refers to the three-phase current of the upstream adjacent main line switch. I represents the three-phase current of multiple branch feeders between the target main line switch and the downstream adjacent main line switch. D1 For upstream differential flow, I D2 For downstream differential flow, I setM I is the phase overcurrent threshold of the target main line switch. setN I is the phase overcurrent threshold of the upstream adjacent main line switch. set4 I is the overcurrent threshold of each branch feeder phase upstream of the target main line switch. set5 I is the differential current threshold of the upstream section. set6 I is the differential current threshold for the downstream section. set7 The threshold value for no current in the switching interval.

[0085] Optionally, in this embodiment of the invention, the CT recognition function is blocked under the following conditions: communication is interrupted, the AC quantity collected by the relay protection terminal at switch M in the upstream section lacks the current of any switch in the section; at least one main line switch in the section has a current greater than I. set Or, at least one of the branch line currents has a switching current greater than I. set4 .

[0086] Optionally, in an embodiment of the present invention, I set I set4 I set5 I set6 The specific values ​​are determined based on the line parameters.

[0087] Another relay protection terminal circuit anomaly identification method provided by this invention divides the switches on the main line into sections between each other. The method identifies whether the CT on the main line or the CT on the branch line is disconnected by calculating the section current differential. The identification accuracy is high. After the CT is identified as disconnected, the combined current of all switches in the section containing the disconnected CT is used as the current of the disconnected switch and participates in the protection calculation. For a single set of distribution network protection, the protection will not be deactivated.

[0088] This invention also provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the methods described in Embodiments 1 and 2.

[0089] This invention also provides a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the methods described in Embodiments 1 and 2.

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0091] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for identifying abnormalities in relay protection terminal circuits, characterized in that: A relay protection terminal applied to a target substation; the target substation is one of multiple substations between two substations; The relay protection terminals of adjacent substations in the plurality of substations communicate with each other in pairs; including: Obtain the three-phase current values ​​of the line at the target substation; the three-phase current values ​​include: the three-phase current of the incoming line bay, the three-phase current of the feeder bay, and the three-phase current of the switch at the substation opposite the incoming line bay. Based on the three-phase current values ​​of the line, calculate the line differential current and the bus differential current respectively; Based on the differential current of the line, the differential current of the bus, and the three-phase current value of the line, determine whether the secondary circuit of the target substation is abnormally disconnected by the CT. The three-phase bus voltage of the target substation is obtained as the first bus three-phase voltage, and the three-phase bus voltage of the substation opposite the incoming line bay of the target substation is obtained as the second bus three-phase voltage; If the switch positions of the incoming line bay switch of the target substation and the switch of the substation opposite the incoming line bay of the target substation are both in the closed position, then the line voltage difference is calculated based on the three-phase voltage of the first bus and the three-phase voltage of the second bus. Based on the line voltage difference and the three-phase current value of the line, determine whether the secondary circuit of the target substation is abnormally disconnected by a PT. Based on the three-phase current values ​​of the line, the line differential current and the bus differential current are calculated respectively, including: The differential current of the line is calculated using the following formula: The bus differential current is calculated using the following formula: in, For the differential current of the line, For the bus differential current, The three-phase current of the incoming line bay is given. The three-phase current of the feeder interval is given. The three-phase current of the switch in the substation opposite the incoming line bay; The CT disconnection anomaly includes incoming line bay CT disconnection anomaly and feeder line bay CT disconnection anomaly; based on the line differential current, the bus differential current, and the line three-phase current values, determining whether the secondary circuit of the target substation has a CT disconnection anomaly includes: Determine whether the following conditions are true: If so, then the secondary circuit incoming line bay CT of the target substation is determined to be abnormally disconnected; Determine whether the following conditions are true: If so, then the secondary circuit feeder bay CT of the target substation is determined to be abnormally disconnected; in, For phase overcurrent threshold, The line differential current threshold. The bus differential current threshold; Calculating the line voltage difference based on the three-phase voltage of the first bus and the three-phase voltage of the second bus includes: calculating the line voltage difference using the following formula: in, The voltage difference of the line, Let be the vector value of the three-phase voltage of the first busbar. This represents the vector value of the three-phase voltage of the second busbar; Based on the line voltage difference and the three-phase current value of the line, determine whether the secondary circuit of the target substation is abnormally disconnected by a PT, including: Determine whether the following conditions are true: If so, then the secondary circuit PT of the target substation is determined to be abnormally disconnected; in, For phase overcurrent threshold, The rated voltage at which the target substation operates. The three-phase current values ​​of the line are given.

2. The method according to claim 1, characterized in that: Also includes: The CT identification function of the target substation is locked if the following conditions are met: communication is interrupted and the collected AC quantity and fault information are not transmitted to the opposite substation. At least one phase current in the interval is greater than a preset threshold. The PT identification function of the target substation is locked if the following conditions are met: communication is interrupted, and the collected AC quantity and fault information are not transmitted to the opposite substation; at least one phase current in the interval is greater than the preset threshold; and all incoming switches of the target substation are in the open position.

3. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as claimed in any one of claims 1-2.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method as described in any one of claims 1-2.

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