A method and system for monitoring multiple parameters of a medium-high voltage power distribution cabinet and early warning of arc fault

Abstract

The application relates to the technical field of electrical monitoring and early warning, and discloses a kind of medium-high voltage distribution cabinet multi-parameter monitoring fault arc early warning method and system, the method comprises: collecting the operating state data of switch operation process, electrical transient data and compartment monitoring data. Establish operation disturbance window. When electrical transient data or compartment monitoring data meet the trigger condition, an event observation window is established. Time sequence comparison is carried out on the event observation window and the operation disturbance window. When the windows coincide, operation arc consistency is determined based on the first compartment, abnormal occurrence period, abnormal repetition characteristics and abnormal duration characteristics, to obtain normal operation arc result or suspected fault arc result. When suspected fault arc result is obtained, or the event observation window and the operation disturbance window do not coincide, sequential closing determination is carried out to obtain fault arc confirmation result. Joint positioning is carried out to obtain the target compartment, and a trip command is output. The application reduces the misoperation rate and improves the early warning reliability.

Description

Technical Field

[0001] This invention relates to the field of electrical monitoring and early warning technology, and more specifically, to a method and system for multi-parameter monitoring of fault arcs in medium and high voltage distribution cabinets. Background Technology

[0002] During the operation of medium and high voltage switchgear, factors such as switch opening and closing, trolley entry and exit, load switching, and insulation degradation can all trigger partial discharge, arc discharge, and transient voltage fluctuations. If a fault arc continues to develop, it can easily cause contact erosion, busbar damage, compartment insulation failure, or even cabinet failure. Therefore, rapid identification, fault nature determination, and timely handling of abnormal discharges inside switchgear have become important research directions in the field of online monitoring and relay protection of switchgear.

[0003] Existing technologies detect and identify arc faults within switchgear by collecting abnormal characterization information such as current, voltage, and light radiation. This aims to reduce false trips and failures to trip while ensuring identification speed, thereby improving the operational safety and power supply reliability of the power distribution system. Chinese invention patent application CN114156831A discloses a photoelectric combined transient fault identification method. After a fault occurs in a switchgear or ring main unit in a power distribution network, it simultaneously collects zero-sequence voltage, zero-sequence current, visible light, and ultraviolet light, and uses joint criteria within the same time domain to identify transient and permanent faults. This scheme can improve the reliability of arc fault identification within the switchgear, but its identification basis is mainly based on the synchronous joint analysis of photoelectric signals after the fault occurs. In actual high-voltage switchgear operation scenarios, the switching operation process itself may be accompanied by short-term arcing, transient current fluctuations, and local optical signal changes. The occurrence time and duration of different types of abnormal signals are not entirely consistent. Therefore, when faced with scenarios where operational disturbances and initial fault anomalies are intertwined, existing solutions still have the problem that short-term anomalies caused by normal operation are not easy to distinguish from real fault arcs, and that it is difficult to simultaneously ensure the timeliness and accuracy of the judgment of complex abnormal processes.

[0004] Therefore, it is necessary to design a multi-parameter monitoring method and system for fault arc early warning in medium and high voltage switchgear to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a multi-parameter monitoring method and system for early warning of fault arcs in medium and high voltage switchgear, which aims to solve the technical problems of difficulty in accurately distinguishing normal operating arcs from actual fault arcs when switch operation disturbances and initial fault anomalies are intertwined in medium and high voltage switchgear, and difficulty in balancing the timeliness and accuracy of judgment in complex abnormal processes.

[0006] This invention proposes a multi-parameter monitoring method for early warning of fault arcing in medium and high voltage switchgear, comprising:

[0007] Collect operational status data, electrical transient data, and compartment monitoring data during switch operation.

[0008] The operational status data is divided into time periods to establish an operational disturbance window;

[0009] When the electrical transient data or the compartment monitoring data meets the triggering conditions, the associated data of the triggering period is intercepted and processed to establish an event observation window;

[0010] The event observation window and the operation disturbance window are compared in time. When the event observation window and the operation disturbance window overlap, the consistency of the operation arc is determined based on the initial compartment, the time period of abnormal occurrence, the abnormal repetition characteristics, and the abnormal persistence characteristics to obtain the normal operation arc result or the suspected fault arc result.

[0011] When the suspected fault arc result is obtained, or when the event observation window and the operation disturbance window do not overlap, the electrical transient data and the compartment monitoring data are sequentially closed to obtain the fault arc confirmation result.

[0012] When the fault arc confirmation result is obtained, the initial compartment, the electrical influence range and the pressure propagation sequence are jointly located to obtain the target compartment, and a cut-off command is output according to the target compartment.

[0013] Furthermore, the operating status data includes circuit breaker operating status, auxiliary contact status, and trolley position status; the electrical transient data includes current surge information and voltage drop information; and the compartment monitoring data includes arc flash information and pressure fluctuation information.

[0014] Furthermore, when performing time-period segmentation processing on the aforementioned operational status data, the following steps are included:

[0015] The time period during which any of the circuit breaker operating state, the auxiliary contact state, and the truck position state changes is defined as the switch operation period. The switch operation period is used as the operation disturbance window, and the operation disturbance window is divided into the initial period, the main operation period, and the stable period.

[0016] Furthermore, when performing the consistency determination of the operating arc, it includes:

[0017] The operation compartment and the preset allowable abnormal period are determined based on the operation status data; the consistency between the initial compartment and the operation compartment is judged, and the time period matching is judged between the abnormal occurrence time and the preset allowable abnormal period; when the initial compartment and the operation compartment are consistent, and the abnormal occurrence time is within the preset allowable abnormal period, it is determined as the normal operation arc result; when the initial compartment and the operation compartment are inconsistent, or the abnormal occurrence time is outside the preset allowable abnormal period, it is determined as the suspected fault arc result.

[0018] Furthermore, when determining the consistency of the operating arc, the method also includes: determining abnormal repetition characteristics and abnormal persistence characteristics based on the arc information in the event observation window; maintaining the normal operating arc result when the number of abnormal repetitions is not greater than a preset number and the cumulative duration of the abnormality is not greater than a preset duration; and determining the result as the suspected faulty arc when the number of abnormal repetitions is greater than a preset number or the cumulative duration of the abnormality is greater than a preset duration.

[0019] Furthermore, when determining the consistency of the operation arc, the method further includes: the preset allowed abnormal period is the period during which the operating status data changes continuously and the preset continuation period after the end of the continuous change; when the abnormal occurrence period is within the preset allowed abnormal period, it is determined as the normal operation arc result by combining the consistency judgment of the initial compartment and the action compartment; when the abnormal occurrence period is outside the preset allowed abnormal period, it is determined as the suspected fault arc result.

[0020] Furthermore, the consistency determination of the operating arc also includes:

[0021] When the abnormality occurs within the preset duration, the presence of a second abnormality is determined based on the arc information in the event observation window. If a second abnormality exists and the cumulative duration of the second abnormality is greater than the preset duration, it is determined to be the suspected fault arc result. If there is no second abnormality, or the cumulative duration of the second abnormality is not greater than the preset duration, the normal operation arc result is maintained.

[0022] Furthermore, when performing sequential closure determination, it includes:

[0023] The initial rapid anomaly is determined based on the arc information, current mutation information, and voltage drop information; the continuous electrical anomaly is determined based on the continuous change of the current mutation information or the continuous change of the voltage drop information; and the compartment confirmed anomaly is determined based on the continuous rise of the pressure fluctuation information. When the initial rapid anomaly, the continuous electrical anomaly, and the compartment confirmed anomaly are successively established, the fault arc confirmation result is obtained.

[0024] Furthermore, when performing joint localization and outputting resection commands, the following are included:

[0025] The initial fault location is determined based on the first compartment, the fault range is corrected based on the electrical influence range, and the target compartment is determined based on the pressure propagation sequence; when the target compartment is a cable compartment, a feeder disconnect command is output; when the target compartment is a circuit breaker compartment, a circuit breaker disconnect command is output; when the target compartment is a busbar compartment, a busbar segment disconnect command is output.

[0026] Compared with existing technologies, the beneficial effects of this invention are as follows: By first distinguishing whether the abnormality occurs during the relevant period of switch operation, and then further combining the initial compartment, the time of abnormality occurrence, the repetitive characteristics of the abnormality, and the continuous characteristics of the abnormality to identify whether it belongs to a normal operation arc or a suspected fault arc, short-term abnormalities in normal processes such as opening and closing and handcart operation are avoided from being misjudged as fault arcs; for abnormal events where the risk of fault cannot be ruled out, fault confirmation is completed by sequential closure judgment of electrical transient data and compartment monitoring data, so that fault identification no longer depends on multiple signals being satisfied at the same time, but gradually converges the judgment result according to the abnormality evolution process, thereby taking into account both the timeliness of identification and the accuracy of judgment; on this basis, by combining the initial compartment, the electrical influence range, and the pressure propagation sequence for joint positioning, and outputting the cut-off command according to the target compartment, it is possible not only to more accurately locate the fault occurrence area, but also to reduce unnecessary expansion of the cut-off range, improve the pertinence of fault handling and the continuity of power supply, and achieve effective differentiation between normal operation disturbances and real fault arcs, reliable confirmation of complex abnormal processes, and precise handling of fault locations, thereby reducing the false operation rate and improving the reliability of early warning.

[0027] On the other hand, this application also provides a multi-parameter monitoring fault arc early warning system for medium and high voltage switchgear, used to apply the above-mentioned multi-parameter monitoring fault arc early warning method for medium and high voltage switchgear, including:

[0028] The acquisition unit is configured to acquire operating status data, electrical transient data, and compartment monitoring data during the switch operation process;

[0029] The processing unit is configured to divide the operating status data into time periods and establish an operation disturbance window; when the electrical transient data or the compartment monitoring data meets the triggering conditions, it extracts the associated data of the triggering time period and establishes an event observation window.

[0030] The detection unit is configured to perform a time-series comparison between the event observation window and the operation disturbance window. When the event observation window and the operation disturbance window overlap, the unit performs an operation arc consistency determination based on the initial compartment, the time period of abnormal occurrence, the abnormal repetition characteristics, and the abnormal persistence characteristics to obtain a normal operation arc result or a suspected fault arc result.

[0031] The determination unit is configured to perform sequential closure determination on the electrical transient data and the compartment monitoring data when the suspected fault arc result is obtained, or when the event observation window and the operation disturbance window do not overlap, to obtain the fault arc confirmation result;

[0032] The output unit is configured to, when the fault arc confirmation result is obtained, jointly locate the initial compartment, the electrical influence range and the pressure propagation sequence to obtain the target compartment, and output a cut-off command based on the target compartment.

[0033] It is understandable that the above-mentioned multi-parameter monitoring fault arc early warning method and system for medium and high voltage switchgear have the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0034] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0035] Figure 1 The flowchart is a multi-parameter monitoring fault arc early warning method for medium and high voltage switchgear provided in an embodiment of the present invention;

[0036] Figure 2 This is a functional block diagram of a multi-parameter monitoring fault arc early warning system for medium and high voltage distribution cabinets provided in an embodiment of the present invention. Detailed Implementation

[0037] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey its scope to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] In some embodiments of this application, see Figure 1 As shown, this application proposes a multi-parameter monitoring method for fault arc early warning in medium and high voltage switchgear, including:

[0039] S100: Collects operating status data, electrical transient data, and compartment monitoring data during switch operation.

[0040] S200: Divide the operating status data into time periods and establish an operation disturbance window. When the electrical transient data or compartment monitoring data meets the triggering conditions, extract the associated data of the triggering period and establish an event observation window.

[0041] S300: Perform time-series comparison between the event observation window and the operation disturbance window. When the event observation window and the operation disturbance window overlap, determine the consistency of the operation arc based on the initial compartment, the time period of the abnormal occurrence, the abnormal repetition characteristics, and the abnormal persistence characteristics to obtain the normal operation arc result or the suspected fault arc result.

[0042] S400: When a suspected fault arc result is obtained, or when the event observation window and the operation disturbance window do not overlap, the electrical transient data and compartment monitoring data are sequentially closed to obtain the fault arc confirmation result.

[0043] S500: When the fault arc confirmation result is obtained, the initial compartment, the range of electrical influence and the pressure propagation sequence are jointly located to obtain the target compartment, and the cut-off command is output according to the target compartment.

[0044] Specifically, this embodiment is applied to medium- and high-voltage switchgear with busbar compartments, circuit breaker compartments, and cable compartments. Operating status data is used to characterize whether a switch operation has occurred and its current stage; electrical transient data is used to characterize rapid abnormal changes in circuit electrical quantities; and compartment monitoring data is used to characterize local abnormal discharges within the cabinet and their accompanying physical effects. To ensure that data from different sources can participate in the same event chain analysis, the above data are time-stamped using a unified time base. The associated data here refers to operating status data, electrical transient data, and compartment monitoring data that have a temporal correlation with the current abnormal event within the triggering period. The overlap between the event observation window and the operation disturbance window means that the start time of the event observation window or the main abnormal time period falls within the operation disturbance window, or that the two have a continuous overlapping relationship in time, rather than requiring the start and end times of the two windows to be completely identical. When establishing the event observation window, it is preferable to retain data for a predetermined duration before triggering and a predetermined duration after triggering. The former is used to form a reference state before the abnormality, and the latter is used to determine whether the abnormality is continuous, repetitive, or expanding. The predetermined duration before and after triggering is preferably determined based on historical samples of the same cabinet type, and the predetermined duration after triggering should cover the maximum expected transmission process from the initial rapid anomaly to the compartment-confirmed anomaly. Triggering conditions should preferably be determined using a boundary-crossing method relative to the normal baseline. The trigger thresholds for arc information, current surge information, voltage drop information, and pressure fluctuation information can all be obtained through joint calibration using normal steady-state samples, fault-free operation samples, and typical fault samples. During calibration, normal samples form the upper bound of permissible disturbances, and fault samples form the lower bound of fault anomalies, with a judgment gap reserved between them. The sequential closure judgment in step S400 does not require multiple anomalies to occur simultaneously at the same time. Instead, it requires that within the same event observation window, the initial rapid anomaly appears first, followed by the persistent electrical anomaly, and finally the compartment-confirmed anomaly, thereby obtaining the fault arc confirmation result. Here, the same event observation window refers to the time interval between the above three types of anomalies not exceeding the preset maximum permissible interval. If this interval is exceeded, it is not considered a continuous evolution of the same abnormal event. The joint location step S500 first determines the initial fault location based on the initial compartment, then corrects the fault boundary based on the electrical influence range, and finally verifies the compartment where the fault is located based on the pressure propagation sequence. Here, the electrical influence range refers to the loop range where abnormal voltage drop or current surge information occurs within the same event observation window, and the pressure propagation sequence refers to the order in which pressure fluctuations in different compartments reach the trigger threshold.

[0045] Preferably, the pre-triggered time is used to preserve the stable baseline before the anomaly occurs, and the post-triggered time is used to cover the complete evolution process from the initial rapid anomaly to the compartment-confirmed anomaly. Both can be determined based on typical event samples of the same cabinet type. Preferably, the pre-triggered time covers at least one complete steady-state sampling interval, and the post-triggered time covers the maximum transmission interval between the initial rapid anomaly, the persistent electrical anomaly, and the compartment-confirmed anomaly, plus a safety margin. The maximum permissible interval is preferably obtained based on the statistical transmission time between two adjacent types of anomalies in typical fault tests, and can be a high-level statistical boundary with an additional safety margin. The electrical impact range is preferably determined based on the set of circuits involved in voltage drop information anomalies and current surge information anomalies within the same event observation window. When the anomaly only occurs on a single feeder, the electrical impact range is considered to be limited to that feeder. When the anomaly extends to the circuit breaker's incoming and outgoing sides, the electrical impact range is considered to cover the circuit breaker's related circuits. When the anomaly affects multiple bays or both sides of the bus tie, the electrical impact range is considered to cover the corresponding bus section.

[0046] Understandably, allowing anomalies during normal operation and persistent anomalies during fault evolution are treated in a hierarchical manner within the same methodological framework. Instead of immediately executing fault handling upon detecting an arc or transient fluctuation, the approach first identifies the operational background, then confirms the anomaly evolution, and finally locates and removes the fault. This improves the reliability of fault identification while reducing the risk of erroneous operation caused by normal operation.

[0047] In some embodiments of this application, the operating status data includes the circuit breaker operating status, auxiliary contact status, and trolley position status; the electrical transient data includes current surge information and voltage drop information; and the compartment monitoring data includes arc flash information and pressure fluctuation information.

[0048] In some embodiments of this application, the process of dividing the running status data into time periods includes:

[0049] The time period during which any of the circuit breaker's operating state, auxiliary contact state, or truck position state changes is defined as the switch operation period. The switch operation period is used as the operation disturbance window, which is then divided into the initial period, the main operation period, and the stable period.

[0050] Specifically, the circuit breaker operating status is used to characterize whether the circuit breaker is in the process of opening, closing, or transitioning; the auxiliary contact status is used to characterize the change of subordinate status during the main operation of the circuit breaker; and the trolley position status is used to characterize whether the trolley is in the working position, test position, or displacement transitioning process. Current surge information is preferably obtained from the surge amount of the circuit current sample value relative to the corresponding baseline value, and voltage drop information is preferably obtained from the decrease in the real-time voltage value relative to the stable operating reference value. Arc flash information is formed from the photosensitive detection results in the compartment, and pressure fluctuation information is formed from the pressure sampling results in the compartment. The baseline value and reference value are jointly determined by the equipment's normal steady-state operation sample and fault-free operation sample, where the normal steady-state sample provides the static background range, and the fault-free operation sample provides the allowable operational disturbance range. If the distribution cabinet is a fixed structure and there is no trolley operation, the trolley position status remains a fixed state quantity and does not affect the use of other operating status data.

[0051] Specifically, the system first identifies whether there are any state changes in the circuit breaker's operating state, auxiliary contact state, and truck position state. When any state transitions from a stable state to a changing state, the starting point of this change is determined as the start of the switching operation period. When all the above states return to stability, and no new state changes occur within a preset stability holding time, this moment is determined as the end of the switching operation period, and this switching operation period is used as the operation disturbance window. To avoid misclassifying continuous small fluctuations in the same operation into multiple independent windows, the intervals between two adjacent state changes are merged. When the interval is less than the preset merging time, it is considered as the same operation process. Both the preset stability holding time and the preset merging time are preferably determined through statistical analysis of fault-free opening, closing, and truck entry / exit samples. The preset stability holding time is preferably taken as the high-level statistical boundary of continuous no change after the state returns to stability, plus a safety margin; the preset merging time is preferably taken as the high-level statistical boundary of the interval between adjacent state changes in the same operation process, plus a safety margin. The initial period in the operational disturbance window characterizes the stage where the operational command has been issued but the main electrical relationship has not yet undergone substantial change. The main operational period characterizes the stage where contact separation, contact switching, or main displacement of the trolley occurs. The stable period characterizes the stage where the main mechanical action has ended but the local transient has not completely dissipated. The three segments are not mechanically divided according to a fixed ratio, but are determined based on the density of changes in the operating state data, the order of changes, and the characteristics of stable recovery. Preferably, the interval from the first change in the circuit breaker's operational state to the beginning of concentrated changes in the auxiliary contact state can be defined as the initial period; the interval where the changes in the auxiliary contact state or trolley position state are most concentrated can be defined as the main operational period; and the remaining disturbance interval after the auxiliary contact state and trolley position state have stabilized can be defined as the stable period. When different state changes overlap, the interval with the more concentrated changes is used as the basis for determining the main operational period.

[0052] Understandably, this provides a stable and reusable timing reference for determining the consistency of the operating arc, allowing short-term arc flashes, transient currents, and local pressure changes to be interpreted. This embodiment avoids missegmenting continuous state fluctuations within the same operation into multiple independent events, thereby improving the stability of the determination boundary under complex operating processes.

[0053] In some embodiments of this application, the process of determining the consistency of the operating arc includes: determining the action compartment and a preset allowable abnormal time period based on the operating status data; determining the consistency between the initial compartment and the action compartment; and determining the time period matching between the abnormal occurrence time and the preset allowable abnormal time period. When the initial compartment and the action compartment are consistent, and the abnormal occurrence time is within the preset allowable abnormal time period, it is determined to be a normal operating arc result. When the initial compartment and the action compartment are inconsistent, or the abnormal occurrence time is outside the preset allowable abnormal time period, it is determined to be a suspected faulty arc result.

[0054] In some embodiments of this application, the process of determining the consistency of the operating arc further includes: determining abnormal repetition characteristics and abnormal duration characteristics based on the arc information in the event observation window. When the number of abnormal repetitions is no greater than a preset number and the cumulative duration of the abnormality is no greater than a preset duration, the normal operating arc result is maintained. When the number of abnormal repetitions is greater than a preset number, or the cumulative duration of the abnormality is greater than a preset duration, it is determined to be a suspected faulty arc result.

[0055] Specifically, the operating compartment refers to the compartment most likely to experience a normal operating arc during the current switch operation. The operating compartment is determined by operating status data, and a judgment rule can be pre-formed based on the combination of circuit breaker operating status, auxiliary contact status, and truck position status. This judgment rule is preferably determined in advance by combining the cabinet structure, primary conductive path, and operation type, with the compartment where the normal operating arc is allowed to appear first under the same operation type pre-recorded in the rule table. This rule is then directly called upon based on the current operating status data to avoid confusion in operating compartment judgment caused by different equipment structures. For example, during the circuit breaker opening or closing process, the circuit breaker compartment is preferably identified as the operating compartment. During the truck's movement from the test position to the working position or from the working position to the test position, the compartment belonging to the primary plug-in contact area can be classified as the circuit breaker compartment to maintain consistent compartment names. The first-response compartment refers to the compartment that first reaches the arc trigger threshold within the same event observation window. If multiple compartments simultaneously reach the trigger threshold within the sampling accuracy range, the compartment with the higher arc peak value is selected as the initial trigger compartment. If they still cannot be distinguished, the compartment with the first abnormal pressure fluctuation is selected as the initial trigger compartment. The abnormal occurrence time period refers to the specific stage of the initial abnormality within the operating disturbance window. When determining the consistency of the operating arc, compartment consistency is determined first, followed by time period matching. Only when both are met simultaneously does the normal operating arc path begin.

[0056] Specifically, the abnormal repetition characteristics include the number of times the arc light abnormality recurs and the interval between two adjacent abnormalities. The abnormal persistence characteristics include the duration of a single abnormality and the cumulative duration. A continuous period of time where the arc light information is above the trigger threshold and before falling back to the reset threshold can be considered as one abnormality. If the interval between two abnormalities is less than the preset separation time, they are combined and considered as the same persistent abnormality. When the arc light information fluctuates between the trigger threshold and the reset threshold, and does not meet the condition of falling back below the reset threshold and maintaining at least the preset separation time, it is not counted as a new abnormality. The reset threshold is lower than the trigger threshold to avoid the arc light signal jittering near the threshold being mistakenly counted as multiple abnormalities. The preset separation time is used to distinguish between intermittent fluctuations of the same abnormality and recurring abnormalities. The reset threshold, preset separation time, preset number of occurrences, and preset duration should all be based on the high-order statistical values ​​of normal samples of the same cabinet type and operation type, and verified in conjunction with the lower bound of typical fault samples. Therefore, the operation arc consistency determination is not a one-time static judgment, but rather a process of first completing the action background access and then verifying the behavior boundary.

[0057] Understandably, even if an anomaly meets the conditions of the action compartment and the permissible time period, it can still be further identified whether it deviates from the normal operating arc boundary through repetitive and continuous behavior. This embodiment enhances the ability to suppress short-term multiple arcs and continuous anomalies, avoiding misjudgments caused by the relaxation of a single condition.

[0058] In some embodiments of this application, the operation arc consistency determination further includes: a preset allowable abnormal period consisting of a period during which the operating status data changes continuously and a preset continuation period after the continuous changes end. When the abnormal occurrence period falls within the preset allowable abnormal period, it is determined as a normal operation arc result by combining the consistency determination of the initial compartment and the action compartment. When the abnormal occurrence period falls outside the preset allowable abnormal period, it is determined as a suspected faulty arc result.

[0059] In some embodiments of this application, the process of determining the consistency of operating arcs further includes:

[0060] When an anomaly occurs within a preset duration, the arc information in the event observation window is used to determine if a secondary anomaly exists. If a secondary anomaly exists and its cumulative duration exceeds a preset duration, it is classified as a suspected fault arc result. If no secondary anomaly exists, or if the cumulative duration of the secondary anomaly does not exceed the preset duration, the normal operation arc result is maintained.

[0061] Specifically, the preset allowable abnormal period is not a fixed time, but is dynamically formed based on the continuous changes in operating status data. A continuously changing period refers to a time range where at least one of the circuit breaker's operating state, auxiliary contact state, and trolley position state is continuously changing, and the interval between adjacent changes does not exceed the preset combined duration. After this continuously changing period ends, a preset extension period is superimposed to obtain the preset allowable abnormal period. The preset extension period is used to cover delayed arcing phenomena caused by residual ionization, mechanical rebound, contact transition, and local energy release trails after contact separation. Its value is preferably determined based on statistical analysis of fault-free operation samples of the same cabinet type and operating type, taking the higher value of the arcing trail duration in normal samples with an added safety margin. Anomalies within the preset allowable abnormal period only qualify for time-based access; they must still be judged as normal operating arcing results after consistency assessment between the initial operation compartment and the operating compartment.

[0062] Specifically, a recurrence of an anomaly refers to a situation where, after the initial anomaly has ended, the arc light information exceeds the trigger threshold again, forming a new anomaly segment. To avoid minor fluctuations near the threshold being misjudged as recurrences, it is preferable to allow the arc light information to fall below the reset threshold and maintain a separation time of at least a preset duration as the criterion for determining the end of the previous anomaly. Only when the trigger threshold is exceeded again under this condition is it considered a recurrence. The cumulative duration of a recurrence refers to the sum of the durations of all recurrences within a preset continuation period, not the longest duration of a single occurrence. The preset duration should preferably be obtained based on the statistical analysis of the cumulative duration of recurrences during the continuation phase in fault-free operation samples, and verified in conjunction with the minimum duration of continuous arc light in typical fault samples. To improve the repeatability of the judgment, parameters related to the preset allowable anomaly period, preset continuation period, reset threshold, preset separation time, and preset duration are preferably established using historical samples under the same equipment category for cabinet-specific analysis. Specifically, at least 20 samples of fault-free opening, closing, and trolley entry / exit operations should be collected first. The duration of continuous changes in operating status, the duration of normal arc wake, the cumulative duration of recurring anomalies during the continuation phase, and the characteristics of arc wave fluctuations returning to normal should be extracted. Then, based on the statistical distribution, a high-level boundary should be selected as the corresponding threshold, and this should be corrected using actual on-site operation samples during the initial commissioning phase. The sample size should ideally cover the three typical operations of opening, closing, and trolley entry / exit for the same cabinet type, ensuring that the preset allowable abnormal period, preset continuation period, and preset duration simultaneously include normal fluctuation boundaries under different operating cycles. When new fault-free operation samples are accumulated for the same cabinet type during the initial on-site commissioning phase, the above boundaries can be rolled over, but the corrected boundaries should still maintain the ability to distinguish known fault samples. This ensures that each threshold is derived from actual equipment behavior, rather than experience-based settings detached from on-site conditions.

[0063] Understandably, extending the time boundary of the normal operation arc from a fixed duration to a dynamic time period bound to the actual action process improves its applicability to different cabinet types and different action rhythms. This embodiment avoids erroneously relaxing the time boundary simply because the anomaly occurs shortly after the operation, thus maintaining consistency between the time boundary and the actual behavior of the equipment. Specific constraints are applied to the gray area most prone to misjudgment shortly after the operation ends, without compressing the normal operation tolerance, but allowing for early identification of suspicious anomalies with continuous and recurring characteristics. This improves the ability to detect early signs of faults.

[0064] In some embodiments of this application, the sequential closure determination includes: determining the initial rapid anomaly based on arc information, current surge information, and voltage drop information; determining the persistent electrical anomaly based on the continuous change in current surge information or the continuous change in voltage drop information; and determining the compartment confirmation anomaly based on the continuous rise in pressure fluctuation information. When the initial rapid anomaly, the persistent electrical anomaly, and the compartment confirmation anomaly are sequentially established, the fault arc confirmation result is obtained.

[0065] In some embodiments of this application, the process of performing joint location and outputting a disconnection command includes: determining the initial fault location based on the initial compartment, correcting the fault range based on the electrical influence range, and determining the target compartment based on the pressure propagation sequence. When the target compartment is a cable compartment, a feeder disconnection command is output. When the target compartment is a circuit breaker compartment, a circuit breaker disconnection command is output. When the target compartment is a busbar compartment, a busbar segment disconnection command is output.

[0066] Specifically, the initial rapid anomaly refers to the earliest abnormal sign that meets the anomaly judgment criteria within the event observation window, which can be triggered by any of the following: abnormal enhancement of arc light information, abnormal jump in current surge information, or abnormal decrease in voltage drop information. A persistent electrical anomaly refers to a situation where, after the initial rapid anomaly occurs, the current surge information or voltage drop information does not quickly return to the normal disturbance pattern, but instead remains outside the corresponding persistent electrical anomaly threshold in subsequent consecutive sampling periods. Preferably, a continuous outside the threshold for three or more consecutive sampling periods can be used as the condition for establishing a persistent electrical anomaly. A compartment-confirmed anomaly refers to a situation where the pressure fluctuation information in the initial compartment shows a continuous upward trend. Preferably, a total increase for three or more consecutive sampling periods, with the cumulative increase exceeding the allowable range of static pressure disturbance, can be used as the condition for establishing a compartment-confirmed anomaly. The allowable range of static pressure disturbance is preferably determined based on the upper bound of pressure fluctuations in fault-free steady-state samples and fault-free operation samples, and can be a high-level statistical boundary with an added safety margin. The sequential establishment of the initial rapid anomaly, persistent electrical anomaly, and compartment-confirmed anomaly does not require the three types of anomalies to occur consecutively without intervals, but rather requires them to meet a clear sequential logical relationship within the same event observation window. To avoid piecing together unrelated disturbances into a fault chain, it is preferable to limit the maximum allowable interval between two adjacent anomalies. This maximum allowable interval can be determined based on the statistical results of the time transmission from electrical anomaly to pressure response in typical fault tests, preferably using a high-order statistical boundary of the transmission time plus a safety margin. The thresholds for the initial rapid anomaly, persistent electrical anomaly, and compartment-confirmed anomaly should all be jointly calibrated using historical normal samples, fault-free operation samples, and typical fault samples. When the initial fault location indicated by the initial compartment is significantly inconsistent with the anomaly propagation boundary indicated by the electrical influence range, the initial fault location is corrected based on the combined results of the electrical influence range and the pressure propagation sequence. Only when the initial compartment, electrical influence range, and pressure propagation sequence are consistent or converge to the same compartment after correction is the compartment identified as the target compartment. When the target compartment is a cable compartment, a feeder disconnect command is output. When the target compartment is a circuit breaker compartment, a circuit breaker tripping command is output. When the target compartment is a busbar compartment, a busbar segment tripping command is output.

[0067] Understandably, fault confirmation no longer relies on multiple signals occurring simultaneously, but rather closes gradually according to the fault evolution pattern, thus balancing fault sensitivity and resistance to false positives. By using a joint location path, the reliability of fault spatial positioning is improved, and the clearing action matches the actual fault location. This embodiment reduces cases of incorrect clearing, overstepping clearing, and excessive clearing range, thereby enhancing the stability of protection action boundaries.

[0068] In summary, by first distinguishing whether the anomaly occurred during the relevant period of switch operation, and then further combining the initial compartment, the time of anomaly occurrence, the recurrence characteristics of the anomaly, and the persistence characteristics of the anomaly to identify whether it belongs to a normal operating arc or a suspected fault arc, short-term anomalies in normal processes such as opening and closing and trolley operation are misjudged as fault arcs. For anomalies where the risk of fault cannot be ruled out, fault confirmation is completed by sequential closure judgment of electrical transient data and compartment monitoring data. This means that fault identification no longer relies on multiple signals being satisfied at the same time, but rather on gradually converging the judgment result according to the anomaly evolution process, thus balancing the timeliness of identification and the accuracy of judgment. On this basis, joint positioning is performed by combining the initial compartment, the electrical influence range, and the pressure propagation sequence, and the cut-off command is output according to the target compartment. This not only can the fault location be more accurately located, but also the unnecessary expansion of the cut-off range can be reduced, improving the pertinence of fault handling and the continuity of power supply. This achieves effective differentiation between normal operating disturbances and real fault arcs, reliable confirmation of complex anomaly processes, and precise handling of fault locations, reducing the false alarm rate and improving the reliability of early warnings.

[0069] Based on another preferred embodiment described above, see [link to preferred embodiment]. Figure 2 As shown, this embodiment provides a multi-parameter monitoring fault arc early warning system for medium and high voltage switchgear, used to apply the above-mentioned multi-parameter monitoring fault arc early warning method for medium and high voltage switchgear, including:

[0070] The acquisition unit is configured to acquire operating status data, electrical transient data, and compartment monitoring data during the switch operation process.

[0071] The processing unit is configured to divide the operating status data into time periods and establish an operation disturbance window. When electrical transient data or compartment monitoring data meets the triggering conditions, the associated data of the triggering period is extracted and processed to establish an event observation window.

[0072] The detection unit is configured to perform a time-series comparison between the event observation window and the operation disturbance window. When the event observation window and the operation disturbance window overlap, the consistency of the operation arc is determined based on the initial compartment, the time period of the abnormal occurrence, the abnormal repetition characteristics, and the abnormal persistence characteristics, so as to obtain the result of the normal operation arc or the result of the suspected fault arc.

[0073] The judgment unit is configured to perform sequential closure judgment on electrical transient data and compartment monitoring data to obtain fault arc confirmation results when a suspected fault arc result is obtained, or when the event observation window and the operation disturbance window do not overlap.

[0074] The output unit is configured to, when the fault arc confirmation result is obtained, jointly locate the initial compartment, the electrical influence range and the pressure propagation sequence, obtain the target compartment, and output a cut-off command based on the target compartment.

[0075] It is understandable that the above-mentioned multi-parameter monitoring fault arc early warning method and system for medium and high voltage switchgear have the same beneficial effects, and will not be elaborated further here.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for multi-parameter monitoring and early warning of fault arcs in medium and high voltage switchgear, characterized in that, include: Collect operational status data, electrical transient data, and compartment monitoring data during switch operation. The operating status data is divided into time periods to establish an operation disturbance window. When the electrical transient data or the compartment monitoring data meets the triggering conditions, the associated data of the triggering time period is extracted and processed to establish an event observation window. The event observation window and the operation disturbance window are compared in time. When the event observation window and the operation disturbance window overlap, the consistency of the operation arc is determined based on the initial compartment, the time period of abnormal occurrence, the abnormal repetition characteristics, and the abnormal persistence characteristics to obtain the normal operation arc result or the suspected fault arc result. When the suspected fault arc result is obtained, or when the event observation window and the operation disturbance window do not overlap, the electrical transient data and the compartment monitoring data are sequentially closed to obtain the fault arc confirmation result. When the fault arc confirmation result is obtained, the initial compartment, the electrical influence range and the pressure propagation sequence are jointly located to obtain the target compartment, and a cut-off command is output according to the target compartment.

2. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage distribution cabinets according to claim 1, characterized in that, The operational status data includes circuit breaker operating status, auxiliary contact status, and trolley position status; the electrical transient data includes current surge information and voltage drop information; and the compartment monitoring data includes arc flash information and pressure fluctuation information.

3. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage switchgear according to claim 2, characterized in that, When performing time-period segmentation processing on the aforementioned operational status data, the following steps are included: The time period during which any of the circuit breaker operating state, the auxiliary contact state, and the truck position state changes is defined as the switch operation period. The switch operation period is used as the operation disturbance window, and the operation disturbance window is divided into the initial period, the main operation period, and the stable period.

4. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage distribution cabinets according to claim 2, characterized in that, When performing consistency determination of operational arcs, the following are included: The operation compartment and the preset allowable abnormal period are determined based on the operation status data; the consistency between the initial compartment and the operation compartment is judged, and the time period matching is judged between the abnormal occurrence time and the preset allowable abnormal period; when the initial compartment and the operation compartment are consistent, and the abnormal occurrence time is within the preset allowable abnormal period, it is determined as the normal operation arc result; when the initial compartment and the operation compartment are inconsistent, or the abnormal occurrence time is outside the preset allowable abnormal period, it is determined as the suspected fault arc result.

5. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage switchgear according to claim 4, characterized in that, When determining the consistency of the operation arc, the method further includes: determining the abnormal repetition characteristics and abnormal persistence characteristics based on the arc information in the event observation window; maintaining the normal operation arc result when the number of abnormal repetitions is not greater than a preset number and the cumulative duration of the abnormality is not greater than a preset duration; and determining the result as the suspected faulty arc when the number of abnormal repetitions is greater than a preset number or the cumulative duration of the abnormality is greater than a preset duration.

6. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage distribution cabinets according to claim 5, characterized in that, When performing the consistency determination of the operation arc, the following is also included: the preset allowable abnormal period is the period during which the operating status data changes continuously and the preset continuation period after the end of the continuous change; when the abnormal occurrence period is within the preset allowable abnormal period, it is determined as the normal operation arc result by combining the consistency judgment of the initial compartment and the action compartment; when the abnormal occurrence period is outside the preset allowable abnormal period, it is determined as the suspected fault arc result.

7. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage distribution cabinets according to claim 6, characterized in that, When performing operational arc consistency determination, the following are also included: When the abnormality occurs within the preset duration, the presence of a second abnormality is determined based on the arc information in the event observation window. If a second abnormality exists and the cumulative duration of the second abnormality is greater than the preset duration, it is determined to be the suspected fault arc result. If there is no second abnormality, or the cumulative duration of the second abnormality is not greater than the preset duration, the normal operation arc result is maintained.

8. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage switchgear according to claim 2, characterized in that, When performing sequential closure determination, the following are included: The initial rapid anomaly is determined based on the arc information, current mutation information, and voltage drop information; the continuous electrical anomaly is determined based on the continuous change of the current mutation information or the continuous change of the voltage drop information; and the compartment confirmed anomaly is determined based on the continuous rise of the pressure fluctuation information. When the initial rapid anomaly, the continuous electrical anomaly, and the compartment confirmed anomaly are successively established, the fault arc confirmation result is obtained.

9. The method for multi-parameter monitoring and fault arc early warning of medium and high voltage switchgear according to claim 8, characterized in that, When performing joint localization and outputting resection commands, the following are included: The initial fault location is determined based on the first compartment, the fault range is corrected based on the electrical influence range, and the target compartment is determined based on the pressure propagation sequence; when the target compartment is a cable compartment, a feeder disconnect command is output; when the target compartment is a circuit breaker compartment, a circuit breaker disconnect command is output; when the target compartment is a busbar compartment, a busbar segment disconnect command is output.

10. A multi-parameter monitoring fault arc early warning system for medium and high voltage switchgear, used to apply the multi-parameter monitoring fault arc early warning method for medium and high voltage switchgear as described in any one of claims 1-9, characterized in that, include: The acquisition unit is configured to acquire operating status data, electrical transient data, and compartment monitoring data during the switch operation process; The processing unit is configured to perform time-segmentation processing on the operating status data and establish an operation disturbance window; When the electrical transient data or the compartment monitoring data meets the triggering conditions, the associated data of the triggering period is intercepted and processed to establish an event observation window; The detection unit is configured to perform a time-series comparison between the event observation window and the operation disturbance window. When the event observation window and the operation disturbance window overlap, the unit performs an operation arc consistency determination based on the initial compartment, the time period of abnormal occurrence, the abnormal repetition characteristics, and the abnormal persistence characteristics to obtain a normal operation arc result or a suspected fault arc result. The determination unit is configured to perform sequential closure determination on the electrical transient data and the compartment monitoring data when the suspected fault arc result is obtained, or when the event observation window and the operation disturbance window do not overlap, to obtain the fault arc confirmation result; The output unit is configured to, when the fault arc confirmation result is obtained, jointly locate the initial compartment, the electrical influence range and the pressure propagation sequence to obtain the target compartment, and output a cut-off command based on the target compartment.

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