A transformer core grounding current monitoring method

Abstract

The present application belongs to the technical field of power equipment state alarm, and relates to a transformer core grounding current monitoring method. The present application obtains grounding current states of core, clamp and oil tank grounding monitoring nodes, forms an initial grounding point state combination, checks the initial grounding point state combination, generates an alarm candidate or a node fault alarm, re-obtains the grounding current states and writes a directional review number, forms a review grounding point state combination, compares the initial grounding point state combination and the review grounding point state combination, generates an external disturbance alarm or a grounding point confirmation alarm, and releases the alarm when each grounding current state returns to normal. The present application solves the problem that a single grounding point state is difficult to distinguish between oil tank external disturbance and core and clamp grounding abnormalities, achieves the effect of using three grounding point state combinations and directional review numbers for classified review, and outputs a fault alarm when there is no effective signal or incompleteness in the node.

Description

Technical Field

[0001] This invention belongs to the field of power equipment status alarm technology, and relates to a method for monitoring transformer core grounding current. Background Technology

[0002] Transformer core grounding current monitoring is the process of collecting and judging the grounding current drawn from the transformer core grounding point to understand the operating status of the core grounding circuit. Large oil-immersed transformers typically have grounding lead-out structures at the core, clamps, and tank. The grounding current monitoring device obtains the grounding current status at the core, clamps, and tank grounding points through the corresponding grounding lead-out structures and transmits the monitoring results to the station control system or central station so that operators can understand the operating status of each grounding point.

[0003] In existing transformer grounding current monitoring, some monitoring methods use the current anomaly at a single grounding point as the basis for alarm. When an abnormal current occurs at the grounding point of the core, clamps, or tank, the monitoring result of a single grounding point is difficult to reflect the status of other grounding points during the same operating period. Operators find it difficult to distinguish the impact of the grounding point's own anomaly from changes in external grounding conditions, which may lead to unclear judgment of the alarm object or alarm location, increasing the workload of on-site verification.

[0004] Existing monitoring devices may also experience issues such as ineffective status updates, missing data, or communication interruptions. When monitoring results cannot reach the monitoring end completely, operators find it difficult to determine whether grounding points that have not received valid status updates have returned to normal, and it is also difficult to determine whether existing alarms should be maintained, checked, or cleared. As a result, alarm information may be inconsistent with the actual operating status of the equipment, affecting operators' use of alarm information and subsequent maintenance arrangements. Summary of the Invention

[0005] In view of this, in order to solve the problems mentioned in the background art, a method for monitoring transformer core grounding current is proposed.

[0006] The objective of this invention can be achieved through the following technical solution: A method for monitoring the grounding current of a transformer core, comprising: S1, obtaining the grounding current status of the core, clamps and oil tank grounding monitoring nodes within the same transformer monitoring cycle, and forming an initial grounding point status combination according to the order of the core, clamps and oil tank.

[0007] S2. Check the initial grounding point status combination.

[0008] S21. If all conditions are normal, return to S1.

[0009] S22. Generate a node fault alarm when there is no valid signal.

[0010] S23. Only abnormal states of the fuel tank can generate external disturbance candidates; normal states of the fuel tank can generate grounding alarm candidates based on abnormal positions of the iron core and clamps.

[0011] S3. The central station receives node fault alarms and outputs them; or when it receives external disturbance candidates or grounding alarm candidates, it re-acquires the grounding current status and writes it into the directional review number to form a review grounding point status combination.

[0012] S4. When the directional review number is returned, if the core, clamp and oil tank states are the same in the initial grounding point state combination and the review grounding point state combination, an external disturbance alarm or grounding point confirmation alarm will be generated and responded according to the candidate type.

[0013] S5. Continuously acquire the grounding current status of the iron core, clamps and oil tank. When all grounding current statuses return to normal, deactivate the external disturbance alarm or grounding point confirmation alarm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention reads the grounding current status of the core, clamp and oil tank grounding monitoring nodes within the same transformer monitoring cycle, and generates external disturbance candidates or grounding alarm candidates according to the location of the abnormal state of the oil tank or the abnormal state of the core and clamp, so that the central station can distinguish between external grounding grid disturbance and transformer grounding point abnormality according to the abnormal state location, thereby reducing the situation where the alarm object and alarm location are deviated.

[0015] (2) This invention generates a node fault alarm when any grounding monitoring node outputs no valid signal, so that the central station can check the status of the corresponding positions of the core, clamp and oil tank in the initial grounding point status combination and the verification grounding point status combination based on the complete returned directional verification number; when the grounding current status of the three grounding points returns to normal, the external disturbance alarm or grounding point confirmation alarm is deactivated, thereby clarifying the alarm confirmation and deactivation conditions and reducing false alarms, missed alarms and long-term alarm retention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of a transformer core grounding current monitoring method according to the present invention;

[0018] Figure 2 This is the process for initial grounding point state combination check and alarm candidate formation in this invention;

[0019] Figure 3 This is a flowchart of the closed-loop process for targeted review, number review, and alarm in this 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] The specific scheme of the transformer core grounding current monitoring method provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Please see Figure 1 As shown, the implementation of the present invention includes S1 to S5: In the existing transformer core grounding current monitoring, it is difficult to distinguish between transformer body grounding abnormality and external grounding grid disturbance when a single grounding point is abnormal. When the monitoring node has no effective signal or the communication link is abnormal, it is difficult to determine the source of the alarm. There is also a lack of clear confirmation and cancellation basis for the generated alarm.

[0024] This invention acquires the grounding current status of the core, clamps, and oil tank grounding monitoring nodes, forms an initial grounding point status combination, generates alarm candidates or node fault alarms, reacquires the grounding current status and writes it into the directional verification number, forms a verification grounding point status combination, generates an external disturbance alarm or grounding point confirmation alarm based on the initial grounding point status combination and the verification grounding point status combination, and deactivates the alarm when each grounding current status returns to normal.

[0025] This invention achieves the effect of diverting external disturbance alarms and grounding point confirmation alarms according to the grounding current status of the iron core, clamps, and oil tank. This allows monitoring nodes with no valid signal or incomplete directional verification numbers to enter corresponding alarm processing for transformer grounding abnormalities, and the equipment alarms are deactivated after each grounding current status returns to normal.

[0026] S1. Obtain the grounding current status of the core, clamps and oil tank grounding monitoring nodes within the same transformer monitoring cycle, and form an initial grounding point status combination according to the order of core, clamps and oil tank.

[0027] The core, clamps, and tank are different grounding objects of the same transformer. In subsequent alarm processing, these three grounding monitoring nodes correspond to the core grounding point, clamp grounding point, and tank grounding point, respectively. If grounding current states from different transformers or different monitoring cycles are used together for status checks, it's impossible to reflect the status distribution of each grounding point within the current monitoring cycle of the target transformer, nor can subsequent alarm candidates be determined based on the status location. Therefore, using the same transformer and the same monitoring cycle as the status reading range, the grounding current state is fixedly categorized into the three locations: core, clamps, and tank. This provides input for subsequent checks of the initial grounding point status combination based on the location of the abnormal state.

[0028] First, when the target transformer enters a monitoring cycle, the grounding current status output by the core grounding monitoring node, clamp grounding monitoring node, and tank grounding monitoring node for the current monitoring cycle is read. When reading the grounding current status output by the core grounding monitoring node, this status is taken as the grounding current status of the core grounding point; when reading the grounding current status output by the clamp grounding monitoring node, this status is taken as the grounding current status of the clamp grounding point; when reading the grounding current status output by the tank grounding monitoring node, this status is taken as the grounding current status of the tank grounding point. The grounding current status output by each grounding monitoring node is one of the following: normal state, abnormal state, or no valid signal state.

[0029] It should be noted that the normal state and the abnormal state are the ground current status output results not indicating that there is a grounding abnormality at the corresponding grounding point and the ground current status output results indicating that there is a grounding abnormality at the corresponding grounding point, while the no valid signal state is the state in which the central station does not receive the valid grounding current output from the node.

[0030] Subsequently, the grounding current status of the core grounding point, the transformer identifier of the target transformer, the monitoring cycle identifier of the current monitoring cycle, and the core grounding monitoring node are bound together to form a grounding point status record for the core grounding monitoring node; the grounding current status of the clamp grounding point, the transformer identifier of the target transformer, the monitoring cycle identifier of the current monitoring cycle, and the clamp grounding monitoring node are bound together to form a grounding point status record for the clamp grounding monitoring node; the grounding current status of the oil tank grounding point, the transformer identifier of the target transformer, the monitoring cycle identifier of the current monitoring cycle, and the oil tank grounding monitoring node are bound together to form a grounding point status record for the oil tank grounding monitoring node. All three grounding point status records contain the same transformer identifier and monitoring cycle identifier, where the transformer identifier is the equipment identifier field corresponding to the target transformer, and the monitoring cycle identifier is the cycle identifier field corresponding to the current monitoring cycle. The inclusion of the target transformer identifier and the monitoring cycle identifier of the current monitoring cycle in all three grounding point status records ensures that each grounding point status record can be located within the current monitoring cycle of the target transformer.

[0031] After the grounding point status records are generated, the grounding point status records of the core grounding monitoring node, clamp grounding monitoring node, and oil tank grounding monitoring node are extracted using the equipment identifier field value of the target transformer and the cycle identifier field value of the current monitoring cycle as extraction conditions. The grounding current status is then read sequentially from these three grounding point status records. Following the order of nodes of the core, clamps, and tank, the grounding current status of the core grounding point is placed in the first position, the grounding current status of the clamp grounding point is placed in the second position, and the grounding current status of the tank grounding point is placed in the third position, forming an initial grounding point status combination. The initial grounding point status combination refers to the ordered three-item status combination formed by the fixed arrangement of the grounding current status of the three grounding points of the core, clamps, and tank according to the first, second, and third positions at the beginning of the status check of the target transformer in the current monitoring cycle. It is used to generate alarm candidates based on the location of abnormal status in subsequent status checks, and to check the grounding current status at the same position in the reviewed grounding point status combination after directional review.

[0032] In addition, when any grounding monitoring node outputs a state without a valid signal, the state record of that grounding point is not deleted, but the state without a valid signal is retained in the corresponding position, so that subsequent state checks can generate node fault alarms based on the state without a valid signal; the remaining grounding point state combinations continue to be used to check the abnormal state locations of the oil tank, iron core and clamps.

[0033] S2. Check the initial grounding point status combination.

[0034] S21. If all conditions are normal, return to S1.

[0035] S22. Generate a node fault alarm when there is no valid signal.

[0036] S23. Only abnormal states of the fuel tank can generate external disturbance candidates; normal states of the fuel tank can generate grounding alarm candidates based on abnormal positions of the iron core and clamps.

[0037] The initial grounding point state combination includes the grounding current status of the core, clamps, and tank within the same transformer and monitoring cycle. The relationship between the states of these three locations determines the classification of subsequent alarm candidates. If any abnormal state is directly used as a ground fault alarm, abnormal tank grounding points and abnormal core / clamping grounding points will be grouped into the same processing path, making it impossible to distinguish between external disturbance candidates and grounding alarm candidates. If a state without a valid signal is still involved in the abnormal location judgment, a grounding monitoring node fault will be mistakenly identified as a transformer grounding anomaly. Therefore, it is necessary to first check the states without valid signals and normal states in the initial grounding point state combination, and then form node fault alarms, external disturbance candidates, or grounding alarm candidates based on the abnormal locations of the tank, core, and clamps.

[0038] First, the grounding current status of the iron core is read from the first position of the initial grounding point state combination, the grounding current status of the clamp is read from the second position, and the grounding current status of the oil tank is read from the third position, maintaining the positional relationship of the three grounding current statuses in the initial grounding point state combination. The system checks whether there is a state with no valid signal among the grounding current statuses of the iron core, clamp, and oil tank. When any grounding current status is a state with no valid signal, the grounding monitoring node corresponding to that position is read, and the grounding monitoring node identifier is written into the node fault alarm, forming a node fault alarm containing the grounding monitoring node identifier. The node fault alarm does not enter the generation process of external disturbance candidates and grounding alarm candidates, but instead enters the processing process of the central station outputting the node fault alarm. When the grounding current statuses of the iron core, clamp, and oil tank are all in normal states, no alarm candidate is generated. The grounding current statuses output by the three grounding monitoring nodes in the next monitoring cycle are re-acquired, and a new initial grounding point state combination is formed according to the order of the iron core, clamp, and oil tank.

[0039] When the initial grounding point state combination does not include a state without a valid signal, and the grounding current states of the core, clamps, and oil tank are not all normal, the oil tank grounding current state is checked. If the oil tank grounding current state is abnormal, the core grounding current state is normal, and the clamp grounding current state is normal, the candidate type is determined as an external disturbance, forming an external disturbance candidate. If the oil tank grounding current state is normal, the core grounding current state and the clamp grounding current state are further checked: if the core grounding current state is abnormal and the clamp grounding current state is normal, a core grounding alarm candidate is formed; if the core grounding current state is normal and the clamp grounding current state is abnormal, a clamp grounding alarm candidate is formed; if both the core grounding current state and the clamp grounding current state are abnormal, a core-clamps associated grounding alarm candidate is formed. The core grounding alarm candidate, clamp grounding alarm candidate, and core-clamps associated grounding alarm candidate are unified as grounding alarm candidates, and the candidate type, initial grounding point state combination, and grounding monitoring node are used to generate alarm candidate records.

[0040] After external disturbance candidates or grounding alarm candidates are formed, an alarm candidate record is established. The alarm candidate record includes the candidate type, initial grounding point state combination, and grounding monitoring node. When an external disturbance candidate is formed, the candidate type is recorded as "external disturbance," and the initial grounding point state combination and the tank grounding monitoring node are written into the alarm candidate record. When a core grounding alarm candidate is formed, the candidate type is recorded as "core grounding," and the initial grounding point state combination and the core grounding monitoring node are written into the alarm candidate record. When a clamping grounding alarm candidate is formed, the candidate type is recorded as "clamping grounding," and the initial grounding point state combination and the clamping grounding monitoring node are written into the alarm candidate record. When a core clamping associated grounding alarm candidate is formed, the candidate type is recorded as "core clamping associated grounding," and the initial grounding point state combination, the core grounding monitoring node, and the clamping grounding monitoring node are written into the alarm candidate record. The candidate type and grounding monitoring node are used to retain the classification results of the alarm candidates and the location of abnormal grounding points.

[0041] After completing the alarm candidate records, check their completeness according to candidate type. When the candidate type is external disturbance, check if the core grounding current state and clamp grounding current state in the initial grounding point state combination are both normal, check if the tank grounding current state is abnormal, and check if the alarm candidate record includes the tank grounding monitoring node. If all conditions are met, the alarm candidate record corresponding to the external disturbance is considered complete. Specifically, when the candidate type is core grounding, clamp grounding, or core-clamping associated grounding, check if the tank grounding current state in the initial grounding point state combination is normal, and check if the alarm candidate record includes the core grounding monitoring node, clamp grounding monitoring node, or both grounding monitoring nodes corresponding to the abnormal state. If both conditions are met, the alarm candidate record corresponding to the grounding alarm candidate is considered complete. When the alarm candidate record is complete, send it to the central station as either an external disturbance candidate or a grounding alarm candidate according to the candidate type; incomplete alarm candidate records are not sent to the central station.

[0042] like Figure 2 As shown, the initial grounding point status combination is checked in the order of core, clamp, and oil tank. A node fault alarm is generated when there is no valid signal. When the grounding current status of the core, clamp, and oil tank are all normal, the grounding current status for the next monitoring cycle is obtained. When the grounding current status of the core and clamp are both normal but the oil tank grounding current status is abnormal, an external disturbance candidate is formed. When the oil tank grounding current status is normal, core grounding alarm candidates, clamp grounding alarm candidates, or core-clamp related grounding alarm candidates are formed based on the abnormal positions of the core and clamp. External disturbance candidates and grounding alarm candidates are written into the alarm candidate record and sent to the central station after integrity checks are completed.

[0043] S3. The central station receives node fault alarms and outputs them; or when it receives external disturbance candidates or grounding alarm candidates, it re-acquires the grounding current status and writes it into the directional review number to form a review grounding point status combination.

[0044] When the central station receives a node fault alarm, it reads the grounding monitoring node identifier from the alarm, sends the alarm to the central station's alarm output, and stops processing the corresponding external disturbance candidate or grounding alarm candidate. When the central station receives external disturbance candidates or grounding alarm candidates, it reads the candidate type and initial grounding point state combination from the alarm candidate record. Based on the state and position of the core, clamps, and oil tank in the initial grounding point state combination, it determines the verification node and its verification responsibility, ensuring that the re-acquired grounding current state corresponds to the grounding point position at the time of candidate formation. This avoids placing node fault alarms, external grounding disturbances, and transformer internal grounding anomalies in the same verification path. The central station uses node fault alarms, external disturbance candidates, and grounding alarm candidates as inputs for subsequent processing and selects the appropriate numbering process based on the input type.

[0045] First, when the candidate type is external disturbance, read the tank grounding current status in the initial grounding point status combination, determine the tank grounding monitoring node as the abnormal status verification node, and determine the iron core grounding monitoring node and the clamp grounding monitoring node as the associated verification node.

[0046] When the candidate type is grounding alarm, the fuel tank grounding monitoring node is designated as the interference investigation node. When the initial grounding point state combination only includes the core abnormal state, the core grounding monitoring node is designated as the abnormal state verification node, and the clamp grounding monitoring node is designated as the associated verification node. When the initial grounding point state combination only includes the clamp abnormal state, the clamp grounding monitoring node is designated as the abnormal state verification node, and the core grounding monitoring node is designated as the associated verification node. When the initial grounding point state combination includes both the core abnormal state and the clamp abnormal state, both the core grounding monitoring node and the clamp grounding monitoring node are designated as abnormal state verification nodes, and the core grounding monitoring node and the clamp grounding monitoring node are mutually designated as associated verification nodes. The above node selection results only change the verification responsibilities and do not change the fixed arrangement order of the core, clamp, and fuel tank grounding monitoring nodes.

[0047] Secondly, the central station records the candidate types, initial grounding point state combinations, and the verification role relationships of abnormal state verification nodes, associated verification nodes, and interference investigation nodes into the same numbered record. The verification role node relationships include the binding content between the verification role and the grounding monitoring node. Specifically, abnormal state verification nodes are used to reread the grounding current state at the initial abnormal location, associated verification nodes are used to reread the grounding current state related to the abnormal location, and interference investigation nodes are used to reread the tank grounding current state to investigate external grounding influences. The central station generates a directional verification number based on the verification role node relationships, ensuring that the candidate type, initial grounding point state combination, and node verification responsibilities remain bound within the same verification process. The directional verification number serves as the sole record carrier for this verification, used to receive the status returned by each grounding monitoring node.

[0048] Then, based on the node relationships of the review roles, the central station sends the directional review number to the core grounding monitoring node, clamp grounding monitoring node, and oil tank grounding monitoring node corresponding to the external disturbance candidate or grounding alarm candidate. Upon receiving the directional review number, the grounding monitoring node reads its current output grounding current status, writes the grounding monitoring node and current grounding current status into the directional review number, and returns the directional review number to the central station according to the node transmission relationship in the directional review number. Based on the grounding monitoring node in the returned number, the central station confirms the source of the status at the core, clamp, and oil tank locations, avoiding writing grounding current statuses from different monitoring cycles or different transformers into the same review record.

[0049] Finally, the central station reads the grounding current status written by the core grounding monitoring node, clamp grounding monitoring node, and oil tank grounding monitoring node from the returned directional verification number. It then arranges the three grounding current statuses in the order of core, clamp, and oil tank to form a verification grounding point status combination. After forming the verification grounding point status combination, the central station retains the candidate types and initial grounding point status combinations from the directional verification number, and performs status verification and alarm generation on the directional verification number and verification grounding point status combination. If the directional verification number is not returned to the central station or if grounding monitoring nodes and grounding current statuses are missing, a complete verification grounding point status combination is not formed.

[0050] S4. When the directional review number is returned, if the core, clamp and oil tank states are the same in the initial grounding point state combination and the review grounding point state combination, an external disturbance alarm or grounding point confirmation alarm will be generated and responded according to the candidate type.

[0051] Both the initial grounding point state combination and the verification grounding point state combination are arranged in the order of core, clamp, and oil tank. The initial grounding point state combination records the grounding current state of the three grounding points when the candidate is formed, while the verification grounding point state combination records the grounding current state reacquired by the three grounding points when the directional verification number returns. If the source and arrangement of the states in the two combinations are not distinguished, the core state may be cross-checked with the clamp state, or a grounding point alarm may be generated directly before the directional verification number is fully returned. Therefore, it is necessary to check the two grounding point state combinations according to the same grounding monitoring node and the same arrangement position, and use the state check result and the state returned by the directional verification number together as the alarm generation condition.

[0052] First, the central station reads the core grounding current status from the first position of the initial grounding point status combination, the clamp grounding current status from the second position, and the oil tank grounding current status from the third position. Then, it reads the core, clamp, and oil tank grounding current status from the first, second, and third positions of the verification grounding point status combination. The central station verifies the core status of the two combinations at the first position, verifies the clamp status of the two combinations at the second position, and verifies the oil tank status of the two combinations at the third position, generating core status verification results, clamp status verification results, and oil tank status verification results respectively. Each status verification only determines whether the same grounding monitoring node belongs to the same normal state, abnormal state, or no effective signal state when the candidate is formed and when the number is returned; no numerical calculations are performed on the grounding current status.

[0053] The central station uses the following logical formula to determine the alarm generation conditions: ,in, This indicates that the status of the grounding point is confirmed, meaning that the status of all three grounding monitoring nodes is consistent and the directional verification number has been returned completely. This represents the grounding current state at the core location in the initial grounding point state combination. To verify the grounding current status of the core position in the grounding point status combination; This refers to the grounding current state at the clamp position in the initial grounding point state combination. To verify the grounding current status of the clamp positions in the grounding point status combination; This represents the grounding current state at the oil tank location in the initial grounding point state combination. To verify the grounding current status of the oil tank location in the grounding point status combination; symbol " "Indicates that the grounding current states at both ends are of the same category, symbol " "" indicates that the adjacent conditions are met simultaneously. This indicates that the targeted review number has been completely returned to the central station. The letter subscript " "Indicates the source of the state in the initial grounding point state combination, indicated by the letter subscript " "" indicates the source of the state in the verification grounding point state combination. This judgment formula is obtained by the three fixed arrangement positions of the iron core, clamp and oil tank and the return condition of the directional verification number, and is not used to calculate the magnitude of the grounding current.

[0054] This judgment formula combines the condition for verifying the state categories of the three grounding points with the condition for the complete return of the directional verification number into a single overall confirmation condition. Only when the state categories of the three locations are identical and the directional verification number is returned in its entirety does it indicate that the grounding current states of the core, clamps, and oil tank in both the initial grounding point state combination and the verification grounding point state combination have been verified at the same location, and the grounding point state confirmation result is obtained. Only if the status category of any location is different or the directional review number is not returned completely, it indicates that the grounding current status of at least one grounding point has not been verified by the same location, or the directional review record is incomplete. None of these results are valid, and the results of this review cannot be used as the basis for confirming the grounding point status.

[0055] When the grounding point status is confirmed Upon establishment, the central station reads the candidate types from the directional review number. When the candidate type is external disturbance, the central station generates an external disturbance alarm and sends it to the alarm output terminal. When the candidate type is core grounding, clamp grounding, or core clamp-related grounding, the central station generates a grounding point confirmation alarm and sends it to the alarm output terminal. The alarm content is bound to the candidate type, the initial grounding point status combination, and the review grounding point status combination, allowing the central station to distinguish between external grounding disturbances and transformer grounding point anomalies, and for subsequent alarm response and recovery status monitoring.

[0056] The complete directional review number was returned to the central station, but the grounding point status confirmation result was not available. If the condition is not met, the central station reads the grounding monitoring nodes that have failed the status verification, retains the external disturbance candidates or grounding alarm candidates in the directional verification number, does not generate external disturbance alarms or grounding point confirmation alarms, and regenerates a new directional verification number based on the retained candidate type and the initial grounding point status combination. It then reselects the abnormal status verification node, associated verification node, and interference investigation node according to the original candidate type, and obtains the grounding current status of the core, clamp, and oil tank grounding monitoring nodes again, so as to continue to verify the candidates that have not formed a consistent status.

[0057] S5. Continuously acquire the grounding current status of the iron core, clamps and oil tank. When all grounding current statuses return to normal, deactivate the external disturbance alarm or grounding point confirmation alarm.

[0058] After an external disturbance alarm or grounding point confirmation alarm is generated, the central station still needs to continuously monitor the grounding current status of the three grounding points: the core, clamps, and oil tank. The initial grounding point status combination and the verification grounding point status combination at the time of alarm generation are used to confirm alarm candidates, while the grounding current status after alarm generation is used to determine whether the alarm meets the conditions for deactivation. If the alarm is deactivated simply because one of the grounding points has returned to normal, the alarm response may stop even if the core, clamps, or oil tank are still in an abnormal state. If the alarm is deactivated when the grounding monitoring node outputs no valid signal, it will be impossible to distinguish between grounding point status recovery and monitoring status loss. Therefore, during the period of external disturbance alarm or grounding point confirmation alarm maintenance, the grounding current status of the core, clamps, and oil tank within the same monitoring cycle is used to form a recovery grounding point status combination, and the corresponding alarm is deactivated only when all three locations have returned to normal.

[0059] First, the central station enters an alarm holding state after an external disturbance alarm or grounding point confirmation alarm is generated. In each subsequent monitoring cycle, the central station acquires the grounding current status output from the core grounding monitoring node, clamp grounding monitoring node, and oil tank grounding monitoring node, respectively. The core grounding current status is placed in the first position of the restored grounding point status combination, the clamp grounding current status in the second position, and the oil tank grounding current status in the third position. The three grounding current statuses originate from the same transformer and the same monitoring cycle. The restored grounding point status combination records the recovery status of the three grounding points within the current monitoring cycle and does not change the candidate type of the generated external disturbance alarm or grounding point confirmation alarm.

[0060] After forming the restored grounding point status combination, the central station sequentially checks the core grounding current status at the first position, the clamp grounding current status at the second position, and the oil tank grounding current status at the third position. When the core grounding current status, clamp grounding current status, and oil tank grounding current status are all normal, the central station determines the current restored grounding point status combination as the basis for alarm cancellation. If the currently held alarm is an external disturbance alarm, the central station cancels the external disturbance alarm; if the currently held alarm is a grounding point confirmation alarm, the central station cancels the grounding point confirmation alarm. When canceling an alarm, the central station simultaneously records the corresponding restored grounding point status combination and alarm type, ensuring that the alarm cancellation action corresponds to the normal status records of the three grounding points.

[0061] After the alarm is cleared, the central station stops processing the alarm and continues to acquire the ground current status and form an initial grounding point status combination in subsequent monitoring cycles to re-enter the ground current status monitoring process. If an abnormal state re-forms in a subsequent monitoring cycle, the initial grounding point status combination is re-examined, and the recovered grounding point status combination that has already cleared the alarm is not used as the new initial grounding point status combination.

[0062] Finally, if an abnormal state exists in the restored grounding point state combination, the central station maintains the current external disturbance alarm or grounding point confirmation alarm, records the location of the core, clamp, or oil tank where the abnormal state occurs, and does not use this restored grounding point state combination to clear the alarm. If a state without a valid signal exists in the restored grounding point state combination, the central station also maintains the current external disturbance alarm or grounding point confirmation alarm, and retains the grounding monitoring node where the state without a valid signal occurs to avoid misjudging the grounding point as normal when the grounding monitoring node does not output a valid state. While maintaining the alarm, the central station enters the next monitoring cycle, reacquires the grounding current status of the core, clamp, and oil tank grounding monitoring nodes, forms a new restored grounding point state combination in the order of core, clamp, and oil tank, and repeats the restored state check until all three grounding current statuses in the new restored grounding point state combination are normal.

[0063] like Figure 3 As shown, after receiving external disturbance candidates or grounding alarm candidates, the central station generates a directional verification number based on the candidate type and the initial grounding point status combination, and sends it to the corresponding grounding monitoring node. If the number is not returned completely, a verification grounding point status combination is not formed. If it is returned completely, a verification grounding point status combination is formed in the order of iron core, clamp, and oil tank, and is checked against the initial grounding point status combination at the same location. If the verification matches, an external disturbance alarm or grounding point confirmation alarm is generated according to the candidate type. If they do not match, the candidate is retained and re-verified. During the alarm holding period, the corresponding alarm is deactivated when all three grounding point statuses return to normal.

[0064] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0065] Those skilled in the art will recognize that the algorithmic steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0066] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

[0068] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for monitoring transformer core grounding current, characterized in that, include: S1. Obtain the grounding current status of the core, clamps and oil tank grounding monitoring nodes within the same transformer monitoring cycle, and form an initial grounding point status combination according to the order of core, clamps and oil tank. S2. Check the initial grounding point status combination; S21. If all conditions are normal, return to S1. S22. Generate a node fault alarm when there is no valid signal. S23. Only abnormal states of the fuel tank can generate external disturbance candidates; when the fuel tank is in normal condition, abnormal positions of the iron core and clamps can generate grounding alarm candidates. S3. The central station receives node fault alarms and outputs them; or when it receives external disturbance candidates or grounding alarm candidates, it re-acquires the grounding current status and writes it into the directional review number to form a review grounding point status combination. S4. When the directional review number is returned, if the core, clamp and oil tank states in the initial grounding point state combination and the review grounding point state combination are the same, then an external disturbance alarm or grounding point confirmation alarm will be generated and responded according to the candidate type. S5. Continuously acquire the grounding current status of the iron core, clamps and oil tank. When all grounding current statuses return to normal, deactivate the external disturbance alarm or grounding point confirmation alarm.

2. The method for monitoring transformer core grounding current as described in claim 1, characterized in that, S1 specifically includes: Within the same transformer monitoring cycle, the grounding current status output by the grounding monitoring nodes of the core, clamps and oil tank is read respectively. The grounding current status includes normal status, abnormal status and no effective signal status. Each grounding current status is associated with a transformer identifier, a monitoring cycle identifier, and a grounding monitoring node, forming a grounding point status record for each grounding monitoring node. Extract the grounding point status records where both the transformer identifier and the monitoring cycle identifier are the same, and arrange the grounding current status in the order of nodes of iron core, clamps and oil tank to form an initial grounding point status combination.

3. The method for monitoring transformer core grounding current as described in claim 1, characterized in that, S2 specifically includes: Check the grounding current status of the core, clamps, and oil tank in the initial grounding point status combination. If there is no valid signal status, generate a node fault alarm containing the grounding monitoring node identifier. When the grounding current status of the iron core, clamps, and oil tank are all in a normal state, return to S1; When the grounding current status of the iron core and clamps is normal and the grounding current status of the oil tank is abnormal, an external disturbance candidate is generated. When the grounding current status of the oil tank is normal, if the grounding current status of the iron core is abnormal and the grounding current status of the clamp is normal, a candidate for iron core grounding alarm is formed; if the grounding current status of the iron core is normal and the grounding current status of the clamp is abnormal, a candidate for clamp grounding alarm is formed; if both the grounding current status of the iron core and the grounding current status of the clamp are abnormal, a candidate for iron core and clamp-related grounding alarm is formed. Candidates for grounding alarms related to iron core, clamps, or iron core and clamps are designated as grounding alarm candidates.

4. The method for monitoring transformer core grounding current as described in claim 3, characterized in that, The methods for generating the external disturbance candidates and the grounding alarm candidates are as follows: Establish alarm candidate records that include candidate types, initial grounding point state combinations, and grounding monitoring nodes; When the grounding current status of the iron core and clamps is normal and the grounding current status of the oil tank is abnormal, the candidate type is recorded as external disturbance, and the initial grounding point status combination and the oil tank grounding monitoring node are written into the alarm candidate record to form an external disturbance candidate. When the grounding current status of the oil tank is normal, the candidate type is recorded as core grounding, clamp grounding, or core clamp associated grounding, and the initial grounding point status combination and grounding monitoring node are written into the alarm candidate record to form grounding alarm candidates.

5. The method for monitoring transformer core grounding current as described in claim 4, characterized in that, The method for determining the integrity of the alarm candidate records is as follows: If the candidate type is an external disturbance and the initial grounding point state combination, and the tank grounding current state is abnormal, and the tank grounding monitoring node is included, then the alarm candidate record is determined to be complete. If the candidate type is core grounding, clamp grounding, or core clamp associated grounding, and the tank grounding current status in the initial grounding point status combination is normal and includes the grounding monitoring node corresponding to the abnormal status, then the alarm candidate record is determined to be complete. When the alarm candidate record is complete, the alarm candidate record is sent to the central station as an external disturbance candidate or a grounding alarm candidate according to the candidate type.

6. The method for monitoring transformer core grounding current as described in claim 1, characterized in that, S3 specifically includes: When the central station receives a node fault alarm, it outputs a node fault alarm. When the central station receives external disturbance candidates or grounding alarm candidates, it selects abnormal state verification nodes, associated verification nodes, and interference investigation nodes based on the candidate type and the initial grounding point status combination. The review roles of abnormal status review nodes, associated review nodes, and interference investigation nodes are bound to the corresponding grounding monitoring node identifiers to form a review role node relationship; Write the candidate type, initial grounding point state combination, and review role node relationship into the same number record to generate a targeted review number; Based on the relationship between the review role nodes, the central station sends the directional review number to the corresponding grounding monitoring node. The grounding monitoring node re-acquires the grounding current status, writes the grounding monitoring node and grounding current status into the directional review number, and returns it to the central station. From the returned directional verification numbers, the central station reads the grounding current status corresponding to the grounding monitoring nodes of the iron core, clamps, and oil tank, and forms a verification grounding point status combination according to the order of iron core, clamps, and oil tank.

7. A method for monitoring transformer core grounding current as described in claim 6, characterized in that, The selection method for the abnormal status verification node, associated verification node, and interference investigation node is as follows: When receiving external disturbance candidates, the oil tank grounding monitoring node is selected as the abnormal state verification node, and the iron core grounding monitoring node and the clamp grounding monitoring node are selected as the associated verification nodes. When receiving grounding alarm candidates, the oil tank grounding monitoring node is selected as the interference investigation node; when only the grounding current status of the iron core is abnormal, the iron core grounding monitoring node is selected as the abnormal status verification node, and the clamp grounding monitoring node is selected as the associated verification node; when only the grounding current status of the clamp is abnormal, the clamp grounding monitoring node is selected as the abnormal status verification node, and the iron core grounding monitoring node is selected as the associated verification node; when the grounding current status of both the iron core and the clamp is abnormal, both the iron core grounding monitoring node and the clamp grounding monitoring node are selected as abnormal status verification nodes, and they are associated verification nodes for each other.

8. The method for monitoring transformer core grounding current as described in claim 1, characterized in that, S4 specifically includes: According to the order of iron core, clamp and oil tank, compare the grounding current state of the same position in the initial grounding point state combination and the verification grounding point state combination respectively, and determine whether the grounding current state of iron core, clamp and oil tank is the same, so as to form the iron core state verification result, clamp state verification result and oil tank state verification result. When the results of the core status verification, clamp status verification, and oil tank status verification are all the same and the grounding current status is the same, and the directional verification number is complete and returned to the central station, an external disturbance alarm is generated when the candidate type is external disturbance, and a grounding point confirmation alarm is generated when the candidate type is core grounding, clamp grounding, or core clamp associated grounding.

9. A method for monitoring transformer core grounding current as described in claim 8, characterized in that, The S4 further includes: If the directional review number is returned in full, and the results of the core status check show that the grounding current status of the core is different, the results of the clamp status check show that the grounding current status of the clamp is different, or the results of the oil tank status check show that the grounding current status of the oil tank is different, then the external disturbance candidate or the grounding alarm candidate is retained, and the process returns to S3 to regenerate the directional review number.

10. A method for monitoring transformer core grounding current as described in claim 1, characterized in that, S5 specifically includes: The central station continuously acquires the grounding current status of the iron core, clamps, and oil tank during the monitoring cycle, and forms a combination of restored grounding point status according to the order of the iron core, clamps, and oil tank. When the grounding current status of the core, clamps and oil tank in the grounding point status combination is all in a normal state, the external disturbance alarm or grounding point confirmation alarm is deactivated. When an abnormal state or no effective signal exists in the restored grounding point state combination, maintain the external disturbance alarm or grounding point confirmation alarm, and continue to acquire the grounding current state of the next monitoring cycle to form a restored grounding point state combination.

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