An integrated switchgear with intelligent diagnosis function

Abstract

This invention discloses an integrated switchgear with intelligent diagnostic functions, belonging to the field of switchgear technology. It aims to solve the technical problems in existing switchgear where contact wear assessment does not differentiate between breaking types, leading to large deviations in wear assessment, and where wear assessment results are disconnected from overload protection settings, causing a mismatch between protection settings and the actual current-carrying capacity of the contacts. This device is based on an integrated switchgear system with intelligent diagnostic functions, including: a breaking event type identification module, which collects the breaking current waveform each time the circuit breaker trips, and automatically identifies the breaking type of the trip by analyzing the waveform characteristics. This invention has the advantages of achieving refined assessment of contact wear through differentiated weighted accumulation of breaking types, and automatically mapping the wear assessment results to overload protection setting gradient adjustments to achieve dynamic matching between protection action characteristics and the actual current-carrying capacity of the contacts.

Description

Technical Field

[0001] The present invention relates to the technical field of complete switchgear, and more specifically, to an integrated complete switchgear with intelligent diagnosis function. Background Art

[0002] As the core equipment in the power distribution link of the power system, the reliable operation of the internal circuit breaker of the complete switchgear is directly related to the power supply continuity and equipment safety. During the process of current interruption by the circuit breaker contacts, the high temperature generated by the arc will cause ablation and loss of the contact materials. With the accumulation of the number of interruptions, the contacts are gradually worn, the contact area is reduced, the contact resistance is increased, and the actual current-carrying capacity decreases accordingly. However, in the prior art, the protection action setting value of the overload protection device is usually set once according to the rated current when the equipment leaves the factory and remains unchanged during the entire operation life cycle of the equipment. This means that a circuit breaker with severely worn contacts and a greatly reduced actual current-carrying capacity still executes the same overload protection setting value as the newly factory-produced equipment. When the actual load current has not reached the factory-setting value but has exceeded the current-carrying capacity that the contacts can currently withstand, the protection device will not act, resulting in continuous overheating of the contacts, accelerating the insulation aging, and even causing contact welding or internal short-circuit accidents in the switchgear, posing serious safety hazards.

[0003] Regarding the monitoring of contact wear, the traditional methods generally adopt a unified cumulative method, without distinguishing the great differences in the degree of contact wear caused by short-circuit interruption, overload interruption and normal operation interruption. During short-circuit interruption, the current is extremely large and the arc energy is concentrated, and the loss of the contacts caused by a single interruption far exceeds that of dozens of normal operation interruptions; the arc energy during overload interruption is between the two. Treating different types of interruption operations equally for wear accumulation will inevitably lead to a serious deviation of the cumulative wear value from the true loss state of the contacts, either overestimating or underestimating, and cannot provide an accurate basis for subsequent condition assessment and protection strategy adjustment. And the contact wear assessment results in the prior art are only used to generate alarm information or maintenance prompts, and are not linked in a closed loop with the overload protection setting value, lacking an effective connection between wear assessment and protection action characteristic adjustment, making "diagnosis" and "protection" separated from each other, and failing to fundamentally solve the problem of the mismatch between the protection setting value and the actual current-carrying capacity of the equipment. In view of this, we propose an integrated complete switchgear with intelligent diagnosis function. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated complete switchgear with intelligent diagnosis function, so as to solve the technical problems that in the existing complete switchgear, the evaluation of contact electrical wear does not distinguish the interruption types, resulting in a large deviation in wear evaluation, and the wear evaluation result is separated from the overload protection setting value, resulting in the mismatch between the protection setting value and the actual current-carrying capacity of the contacts.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an integrated switchgear with intelligent diagnostic function, implemented based on an integrated switchgear system with intelligent diagnostic function, comprising:

[0006] The circuit breaker tripping event type identification module collects the tripping current waveform each time the circuit breaker trips. By analyzing the characteristics of the tripping current waveform, it automatically identifies the tripping type of the tripping operation. The tripping types include short-circuit tripping, overload tripping, and normal operation tripping.

[0007] The break type weighted wear accumulation module presets wear weight coefficients for each break type. After each break action, it selects the corresponding wear weight coefficient according to the break type output by the break event type identification module, calculates the effective contribution of this break action to the contact electrical wear, and accumulates the effective contribution to the contact cumulative electrical wear register.

[0008] The contact remaining current carrying capacity estimation module determines the contact remaining current carrying capacity based on the cumulative electrical wear value in the contact cumulative electrical wear register and in combination with the preset contact electrical wear characteristic curve.

[0009] The overload protection setting gradient adjustment module divides the overload protection action setting into multiple gradient levels and adjusts them in stages according to the remaining current carrying capacity of the contacts. For each preset decrease in the remaining current carrying capacity of the contacts, the overload protection action setting is lowered by one level.

[0010] The setting value sending module sends the overload protection action setting value after gradient adjustment to the protection device to update the overload protection action characteristics of the protection device.

[0011] Preferably, when the break type weighted wear accumulation module calculates the effective contribution of the current break action to the contact electrical wear, it first obtains the break current waveform corresponding to the current break action, calculates the Joule integral value of the break current during the break process, and then multiplies the Joule integral value with the wear weight coefficient corresponding to the current break type to obtain the effective contribution of the current break action.

[0012] The Joule integral of the breaking current during the breaking process Calculate using the following formula:

[0013] ;

[0014] in, This represents the instantaneous value of the current as it changes over time during the breaking process. The starting time of the segmentation, The end time of the segmentation.

[0015] Effective contribution of this segmentation action Calculate using the following formula:

[0016] ;

[0017] in, This is the Joule integral of the breaking current during the breaking process. The wear weighting coefficient corresponds to the breakage type. This represents the effective contribution of this disconnection action to the contact wear.

[0018] Preferably, the break type weighted wear accumulation module further includes an arcing time correction factor when calculating the effective contribution of this break action;

[0019] The arcing time correction factor is related to the arcing duration detected in this disconnection action. The longer the arcing duration, the larger the value of the arcing time correction factor.

[0020] Effective contribution of this shunt action after taking into account the arc time correction factor Calculate using the following formula:

[0021] ;

[0022] in, This refers to the duration of arcing detected during this interruption action. This is the arc time correction factor function. The effective contribution without arc time correction. This is the effective contribution of this disconnection action after taking into account the arcing time correction factor.

[0023] Preferably, before determining the remaining current carrying capacity of the contact based on the cumulative electrical wear value, the contact remaining current carrying capacity estimation module also detects whether the cumulative electrical wear value has reached the wear warning threshold;

[0024] When the cumulative electrical wear value reaches the wear warning threshold, the contact remaining current carrying capacity estimation module generates a contact replacement warning signal.

[0025] Preferably, when the overload protection setting gradient adjustment module divides the overload protection action setting into multiple gradient levels for graded adjustment, the higher the remaining current carrying capacity of the contacts, the closer the overload protection action setting is to the factory setting value; the lower the remaining current carrying capacity of the contacts, the greater the downward adjustment of the overload protection action setting.

[0026] The downward adjustment of the overload protection action setting shall not exceed the preset upper limit.

[0027] Preferably, the overload protection setpoint gradient adjustment module is also equipped with an adjustment strategy verification function;

[0028] After each overload protection action setting is lowered, the overload protection setting gradient adjustment module monitors the load current and protection action records within the subsequent preset time window.

[0029] If a malfunction occurs due to a reduction in the setpoint within the preset time window, the overload protection setpoint gradient adjustment module will automatically restore the overload protection action setpoint to the value before the adjustment.

[0030] Preferably, it also includes an edge computing unit and a communication module;

[0031] The interruption event type identification module, interruption type weighted wear accumulation module, contact remaining current carrying capacity estimation module, overload protection setpoint gradient adjustment module, and setpoint distribution module are all deployed in the edge computing unit;

[0032] The communication module is used to upload diagnostic data and setpoint adjustment records from the edge computing unit to the cloud platform.

[0033] Preferably, it also includes a cloud data aggregation and trend analysis module, which aggregates historical data of cumulative contact electrical wear and overload protection setting adjustment records uploaded by multiple sets of switchgear, and establishes a typical contact electrical wear curve library and a setting adjustment strategy knowledge base according to equipment model and operating environment.

[0034] Preferably, the cloud data aggregation and trend analysis module will also periodically distribute the established typical contact electrical wear curve library and setpoint adjustment strategy knowledge base to the edge computing units of each complete set of switchgear, in order to update the preset contact electrical wear characteristic curves and the gradient division mapping relationship of the overload protection setpoint gradient adjustment module.

[0035] Preferably, the contact electrical wear characteristic curve is a curve showing the relationship between the cumulative electrical wear value of the contact obtained through experimental calibration and the remaining current carrying capacity of the contact.

[0036] The contact remaining current carrying capacity estimation module takes the cumulative electrical wear value in the contact cumulative electrical wear register as input, and outputs the corresponding contact remaining current carrying capacity by querying the contact electrical wear characteristic curve or by interpolating based on the contact electrical wear characteristic curve.

[0037] Cumulative electrical wear value of contacts The cumulative sum of the effective contributions of each segmentation action is calculated using the following formula:

[0038] ;

[0039] in, For the first The effective contribution of the second interruption action after arc time correction. For the first The wear weight coefficient corresponding to the type of breakage in the secondary breakage action. For the first The Joule integral value of the next segmentation action. For the first The arc time correction factor function value for the second interruption action. This represents the total number of tripping operations of the circuit breaker since it was put into operation or the last contact replacement. This represents the cumulative electrical wear value of the contacts.

[0040] The contact residual current capacity estimation module is based on the cumulative electrical wear value. Determine the remaining current carrying capacity of the contacts The calculation relationship is expressed as follows:

[0041] ;

[0042] in, This refers to the remaining current-carrying capacity of the contacts. The mapping function characterized by the contact electrical wear characteristic curve;

[0043] when When it is zero Equal to the initial rated current capacity, when When the end-of-life threshold is reached Reduce to the preset minimum allowed value.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] 1. This invention achieves differentiated wear weight assignment and refined cumulative calculation for different disconnection types by setting up a disconnection event type identification module and a disconnection type weighted wear accumulation module. Based on the characteristics of the disconnection current waveform, this invention automatically identifies the type of each disconnection operation and assigns different wear weight coefficients, ensuring that the cumulative electrical wear value truly reflects the actual wear state of the contacts. This effectively avoids the wear assessment bias caused by the indiscriminate accumulation in existing technologies.

[0046] Based on this, the overload protection setting gradient adjustment module divides the overload protection action setting into multiple gradient levels and adjusts them in stages according to the residual current carrying capacity of the contacts corresponding to the cumulative electrical wear value. For every certain decrease in the residual current carrying capacity of the contacts, the protection setting is adjusted downwards by one level, ensuring that the protection action characteristics and the actual current carrying capacity of the contacts remain dynamically matched. When contact wear leads to a decrease in current carrying capacity, the sensitivity of the protection device to overload faults increases synchronously, enabling timely fault isolation before contact overload damage. This solves the protection mismatch problem caused by a continuous decrease in the actual current carrying capacity of the contacts due to a fixed protection setting, significantly improving the operational safety and protection reliability of the complete switchgear.

[0047] 2. This invention further refines the wear assessment within the same breaking type by introducing an arcing time correction factor into the weighted wear accumulation module based on breaking type. Even within the same breaking type, the actual arcing duration of different breaking actions may differ. The longer the arcing time, the more thorough the arc's erosion of the contact material, resulting in more severe wear. This invention uses the arcing duration as a correction variable, dynamically adjusting the effective contribution of each breaking action through a correction factor function that monotonically increases with the arcing time. After dual calibration using breaking type weighting and arcing time correction, the accuracy of the cumulative electrical wear value is further improved, providing a more solid data foundation for reliable estimation of the contact's remaining current carrying capacity and reasonable adjustment of overload protection settings.

[0048] 3. This invention also constructs an edge-cloud collaborative system architecture by setting up edge computing units, communication modules, and cloud data aggregation and trend analysis modules. Each diagnostic and adjustment module is deployed in the edge computing unit, ensuring local real-time response capabilities for wear assessment and setting adjustment. Even in the event of communication interruption, the edge side can still independently complete core diagnostic and protection functions. Simultaneously, the cloud platform aggregates historical data on cumulative contact electrical wear and overload protection setting adjustment records uploaded by multiple sets of switchgear. It establishes a typical contact electrical wear curve library and a setting adjustment strategy knowledge base, categorized by equipment model and operating environment, and periodically distributes these to each edge computing unit. This mechanism allows the wear assessment model and protection adjustment strategy of a single device to benefit from the large-scale data accumulation of the group of devices. As operating time increases, the contact electrical wear characteristic curves and gradient mapping relationships are continuously optimized, simultaneously improving diagnostic accuracy and protection adaptability. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the overall system framework of the present invention;

[0050] Figure 2 This is a schematic diagram illustrating the calculation logic of cumulative contact electrical wear and remaining current carrying capacity in this invention.

[0051] Figure 3 This is a schematic diagram of the edge-cloud collaborative data interaction architecture of the present invention;

[0052] Figure 4 This is a schematic diagram of the closed-loop adjustment and verification of the overload protection setting value of the present invention. Detailed Implementation

[0053] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0054] Example 1, such as Figures 1-4As shown, the present invention provides an integrated switchgear with intelligent diagnostic function. The device is based on an integrated switchgear system with intelligent diagnostic function and includes:

[0055] The tripping event type identification module is configured to collect the tripping current waveform each time the circuit breaker trips, and automatically identify the tripping type of the tripping operation by analyzing the characteristics of the tripping current waveform. The tripping type includes three categories: short-circuit tripping, overload tripping, and normal operation tripping.

[0056] The interruption event type identification module automatically identifies the interruption type by analyzing the characteristics of the interruption current waveform, including:

[0057] The relationship between the peak breaking current and the rated current of the circuit breaker is used as the primary identification criterion. During short-circuit breaking, this multiple is usually much greater than that during overload breaking, while during overload breaking, this multiple is greater than that during normal operation breaking.

[0058] The duration of the breaking current is used as the second identification criterion. The current duration of short-circuit breaking is shorter, followed by overload breaking, and the current duration of normal operation breaking is usually longer.

[0059] The presence of short-circuit transient components in the breaking current waveform is used as the third identification criterion. The current waveform during short-circuit breaking usually contains obvious non-periodic decay components, while the current waveforms during overload breaking and normal operation breaking are dominated by periodic components.

[0060] The event type identification module integrates at least two of the above three identification criteria and outputs the determination result of the event type.

[0061] The specific judgment rules are as follows: Peak breaking current multiple threshold: The peak breaking current is compared with the rated current of the circuit breaker. The ratio is used as the first discriminant feature. A first threshold is set. Second threshold : When peak multiple At that time, it was initially determined to be a candidate for short-circuit disconnection; when Peak multiple At that time, it was initially determined to be a candidate for overload tripping; When peak multiple At that time, it was initially determined to be a candidate for normal operation segmentation.

[0062] Breaking duration threshold: The total time from the start of the breaking current to zero is used as the second discrimination feature. A third threshold is set. Fourth threshold: When the duration At that time, it supports short-circuit disconnection determination; when Duration At that time, it supports overload disconnection determination; When the duration is specified, normal operation segmentation is supported.

[0063] Transient component proportion threshold: The ratio of the amplitude of the non-periodic decay component to the amplitude of the periodic component in the breaking current waveform is extracted as the third discriminant feature. A fifth threshold is set. : When the transient component accounts for At that time, it supports short-circuit disconnection determination; When the transient component accounts for At the same time, it supports overload disconnection or normal operation disconnection determination.

[0064] The interruption event type identification module uses a majority voting mechanism to combine the above three features to output the final judgment result: when at least two features point to the same interruption type, the type identifier is output; if the three features point to different types, the transient component proportion feature is given priority. The above thresholds can be calibrated within ±15% based on the factory test data of different circuit breaker models.

[0065] In actual operation, when the circuit breaker performs a tripping action, the current sensor collects the current waveform data in real time during the tripping process and transmits it to the tripping event type identification module. This module first extracts the peak value of the tripping current and compares it with a preset rated current multiple threshold to preliminarily determine the possible range of the tripping type;

[0066] Subsequently, the duration of the breaking current from its start to zero is calculated, and cross-validation is performed by combining the presence or absence of transient components in the current waveform. Finally, the determined breaking type identifier is output.

[0067] The break type weighted wear accumulation module is configured to preset wear weight coefficients for the three break types respectively, wherein the wear weight coefficient of short circuit break is greater than the wear weight coefficient of overload break, and the wear weight coefficient of overload break is greater than the wear weight coefficient of normal operation break.

[0068] The disconnection type weighted wear accumulation module is further configured to select the corresponding wear weight coefficient according to the disconnection type output by the disconnection event type identification module after each disconnection action, calculate the effective contribution of this disconnection action to the contact electrical wear, and accumulate the effective contribution to the contact cumulative electrical wear register.

[0069] The wear weighting coefficient is set based on the physical differences in the degree of contact material ablation caused by different types of interruption: during short-circuit interruption, the arc energy is highly concentrated, resulting in the most severe ablation and material vaporization on the contact surface; during overload interruption, the arc energy is relatively dispersed, resulting in less ablation; and during normal operation interruption, the arc energy is minimal, resulting in the least ablation. Typical values ​​were obtained through standard break test calibration: Short-circuit breaking wear weighting factor The value range is 8-12, with 10 being the preferred value; Overload breakage wear weighting coefficient The value range is 2-4, with 3 being the preferred value; Normal operation breakage wear weighting coefficient The value range is 0.8-1.2, with a preferred value of 1.

[0070] All three conditions are met. The preset size relationship, the above coefficients can be adjusted according to different contact materials (such as copper-tungsten alloy, silver-graphite alloy).

[0071] When calculating the effective contribution of the current breaking action to the contact electrical wear of the interruption type weighted wear accumulation module, it first obtains the breaking current waveform corresponding to the current breaking action, and calculates the Joule integral value of the breaking current during the breaking process. The Joule integral value characterizes the cumulative thermal shock effect of the arc energy on the contact and is a fundamental physical quantity for measuring the degree of electrical wear caused by a single breaking action. The calculation of the Joule integral value is based on the integral of the square of the instantaneous value of the breaking current over time, and the integration interval is from the start time of the breaking action to the end time of the breaking action, completely covering the arc duration.

[0072] Wherein, the Joule integral value of the breaking current during the breaking process Calculate using the following formula:

[0073] ;

[0074] in, The instantaneous value of the current changing over time during the breaking process is obtained by real-time acquisition by the current sensor and analog-to-digital conversion;

[0075] The breaking start time is defined as the moment when the circuit breaker contacts begin to separate and the electric arc begins to be generated.

[0076] The breaking time is defined as the moment when the arc is completely extinguished and the breaking current drops to zero.

[0077] Then, the Joule integral value is multiplied by the wear weight coefficient corresponding to the current breakage type to obtain the effective contribution of this breakage action;

[0078] When short-circuit interruption occurs, the wear weighting coefficient corresponding to short-circuit interruption is selected; when overload interruption occurs, the wear weighting coefficient corresponding to overload interruption is selected; and when normal operation interruption occurs, the wear weighting coefficient corresponding to normal operation interruption is selected. Since the weighting coefficient for short-circuit interruption is the largest, followed by overload interruption, and then normal operation interruption, even if the Joule integral values ​​of multiple interruption actions are similar, their effective contribution to contact wear will show significant differences due to different interruption types, which is more consistent with actual wear patterns.

[0079] The effective contribution of this segmentation action Calculate using the following formula:

[0080] ;

[0081] in, It is the Joule integral of the breaking current during the breaking process, with dimensions of current squared multiplied by time, characterizing the cumulative thermal shock effect of arc energy on the contact.

[0082] Here, represents the wear weighting coefficient corresponding to the segmentation type, and is a dimensionless scaling factor. The subscript 'type' takes values ​​based on the determination result of the segmentation event type identification module. (short circuit breaking), (Overload disconnection) or (Normal operation segmentation), all three conditions are met. Preset size relationships;

[0083] This is the effective contribution of this disconnection action to the contact electrical wear, with dimensions consistent with the Joule integral value, and serves as the basic incremental unit for subsequent cumulative wear calculations.

[0084] The break type-weighted wear accumulation module is further configured to include an arcing time correction factor when calculating the effective contribution of the current break action. This arcing time correction factor is related to the arcing duration detected during the current break action; the longer the arcing duration, the larger the value of the arcing time correction factor. The physical basis of this correction mechanism is that even within the same break type, the actual arcing duration of different break actions may still differ. The longer the arcing time, the more thorough the continuous ablation of the contact material by the arc, resulting in more severe wear. By introducing the arcing time correction factor, the wear assessment accuracy can be further refined based on the break type weighting.

[0085] Among them, the effective contribution of this interruption action after taking into account the arcing time correction factor. Calculate using the following formula:

[0086] ;

[0087] in, The duration of arcing detected during this disconnection operation is calculated from the moment the arc is generated until the moment the arc is extinguished.

[0088] This is the arc duration correction factor function, a dimensionless function with arc duration as the independent variable. This function satisfies the properties that its value is not less than 1 and increases monotonically with the increase of the independent variable; the longer the arc duration, the greater the correction magnitude. The arc time correction factor function adopts a linear piecewise function form, and its specific expression is as follows: ; in, The baseline arcing time is set between 5 and 10 ms, with a preferred value of 8 ms. To maximize the correction arc time, the value range is 30-50ms, with 40ms being the preferred value; To correct the slope, the value range is 0.02-0.05ms. -1 The preferred value is 0.03ms -1 ; The maximum correction factor has a value range of 1.8-2.2, with a preferred value of 2.0.

[0089] The effective contribution without arc time correction is used as the baseline input for correction calculation;

[0090] The effective contribution of this disconnection action after taking into account the arcing time correction factor is used as the final incremental value accumulated in the contact cumulative electrical wear register;

[0091] The wear accumulation module for the break type has a fixed ratio for the wear weight coefficients of the three break types. The wear weight coefficient for short circuit break is a preset multiple of the wear weight coefficient for overload break, and the wear weight coefficient for overload break is a preset multiple of the wear weight coefficient for normal operation break.

[0092] The contact remaining current carrying capacity estimation module is configured to determine the contact remaining current carrying capacity based on the cumulative electrical wear value in the contact cumulative electrical wear register and in combination with a preset contact electrical wear characteristic curve.

[0093] Before determining the remaining current carrying capacity of the contact based on the cumulative electrical wear value, the remaining current carrying capacity estimation module is also configured to detect whether the cumulative electrical wear value has reached the wear warning threshold; when the cumulative electrical wear value reaches the wear warning threshold, the remaining current carrying capacity estimation module generates a contact replacement warning signal.

[0094] The contact electrical wear characteristic curve is the curve showing the relationship between the cumulative electrical wear value of the contact obtained through experimental calibration and the remaining current carrying capacity of the contact. The remaining current carrying capacity estimation module takes the cumulative electrical wear value in the contact cumulative electrical wear register as input, and outputs the corresponding remaining current carrying capacity by querying the contact electrical wear characteristic curve or by interpolating based on the contact electrical wear characteristic curve. The contact electrical wear characteristic curve is a monotonically decreasing curve obtained through standard life test calibration, and is fitted using a cubic polynomial: ; in, This refers to the initial rated current-carrying capacity of the circuit breaker; The contact life termination threshold is set as the cumulative electrical wear value corresponding to the rated short-circuit breaking number of this type of circuit breaker. The fitting coefficients typically take the value of [value missing]. ... It can be recalibrated using experimental data.

[0095] Set wear warning threshold When the cumulative electrical wear value At that time, a first-level contact replacement warning signal is generated; a lifespan end threshold is set. ,when At that time, a secondary forced replacement warning signal is generated, and the circuit breaker closing circuit is blocked.

[0096] Among them, the cumulative electrical wear value of the contact The cumulative sum of the effective contributions of each segmentation action is calculated using the following formula:

[0097] ;

[0098] in, For the first The effective contribution of the secondary interruption action after arc time correction, subscript This serves as the sequence number identifier for the discontinuation action;

[0099] For the first Wear weight coefficient corresponding to the type of breakage in the next breakage action;

[0100] For the first The Joule integral value of the next segmentation action;

[0101] For the first The arc time correction factor function value for the second interruption action;

[0102] This represents the total number of tripping operations of the circuit breaker since it was put into operation / last contact replacement;

[0103] The cumulative electrical wear value of the contact is the algebraic sum of the effective contributions of all historical breaking actions. Its dimension is consistent with the single contribution value, and it comprehensively reflects the total degree of electrical wear that the contact has endured.

[0104] The contact residual current capacity estimation module is based on the cumulative electrical wear value. Determine the remaining current carrying capacity of the contacts The calculation relationship is expressed as follows:

[0105] ;

[0106] in, The remaining current-carrying capacity of the contacts can be expressed as an absolute current-carrying capacity value in units of current, or as a percentage relative to the initial rating.

[0107] The mapping function characterized by the contact electrical wear characteristic curve is a function that corresponds from the cumulative electrical wear amount to the remaining current carrying capacity, obtained through experimental calibration. This function has a monotonically decreasing property, and its domain covers the entire wear amount range from zero to the end-of-life threshold.

[0108] when When it is zero Equal to the initial rated current capacity, when When the end-of-life threshold is reached Reduce to the preset minimum allowed value.

[0109] The overload protection setting gradient adjustment module is configured to divide the overload protection action setting into multiple gradient levels and adjust them in stages according to the remaining current carrying capacity of the contact. For each preset decrease in the remaining current carrying capacity of the contact, the overload protection action setting is adjusted down by one level.

[0110] When the overload protection setting gradient adjustment module divides the overload protection action setting into multiple gradient levels for graded adjustment, the higher the remaining current carrying capacity of the contacts, the closer the overload protection action setting is to the factory setting value; the lower the remaining current carrying capacity of the contacts, the greater the adjustment range of the overload protection action setting; and the adjustment range of the overload protection action setting does not exceed the preset upper limit value. The overload protection setting gradient adjustment module divides the overload protection action setting into 5 gradient levels, with the specific division rules as follows:

[0111] The maximum downward adjustment of the overload protection action setting is 30%, that is, not less than This ensures that basic protection functions are not affected.

[0112] The overload protection setting gradient adjustment module is also equipped with an adjustment strategy verification function; after each overload protection action setting is lowered, the overload protection setting gradient adjustment module monitors the load current and protection action records within the subsequent preset time window; if a protection malfunction occurs due to the setting reduction within the preset time window, the overload protection setting gradient adjustment module automatically restores the overload protection action setting to the setting before this adjustment; The preset time window is set to 72 hours. The logic for determining protection malfunction is as follows: within the time window, the actual load current when the protection device operates is less than the overload protection setting before adjustment and greater than the setting after adjustment, while no short circuit or ground fault characteristics are detected. If the above situation occurs, the module automatically reverts to the previous setting and marks the gradient as pending verification, and will be reactivated after the updated gradient mapping relationship is sent from the cloud.

[0113] The number of gradient levels divided by the overload protection setpoint gradient adjustment module is a preset value, and the setpoint reduction range between adjacent gradient levels is the same or increases as the remaining current carrying capacity decreases.

[0114] The setting value sending module is configured to send the gradient-adjusted overload protection action setting value to the protection device to update the overload protection action characteristics of the protection device.

[0115] In embodiments of the present invention, an edge computing unit and a communication module are also included; the interruption event type identification module, the interruption type weighted wear accumulation module, the contact remaining current carrying capacity estimation module, the overload protection setting gradient adjustment module, and the setting distribution module are all deployed in the edge computing unit; the communication module is used to upload the diagnostic data and setting adjustment records in the edge computing unit to the cloud platform;

[0116] The edge computing unit is also equipped with a local data caching function; when the communication connection between the communication module and the cloud platform is interrupted, the edge computing unit will temporarily store the diagnostic data and set value adjustment records to be uploaded in the local storage unit, and automatically re-upload them to the cloud platform after the communication connection is restored.

[0117] In embodiments of the present invention, a cloud data aggregation and trend analysis module is also included, configured to aggregate historical data of cumulative contact electrical wear and overload protection setting adjustment records uploaded by multiple sets of switchgear, and to establish a typical contact electrical wear curve library and a setting adjustment strategy knowledge base according to equipment model and operating environment.

[0118] The cloud-based data aggregation and trend analysis module is also configured to periodically distribute the established typical contact electrical wear curve library and setpoint adjustment strategy knowledge base to the edge computing units of each complete set of switchgear, in order to update the preset contact electrical wear characteristic curve and the gradient division mapping relationship of the overload protection setpoint gradient adjustment module.

[0119] Algorithm for generating typical contact wear curves: The cloud platform uses the K-means clustering algorithm to process data from devices of the same model and operating environment. First, the cumulative electrical wear-remaining current capacity data of all equipment are normalized. The number of cluster centers is set to 5, and Euclidean distance is used as the similarity measure. A cubic polynomial fit was performed on the data within each cluster to obtain the typical electrical wear curve corresponding to that cluster. Calculate the confidence level of each typical curve, and store the curves with a confidence level greater than 90% in the typical curve library.

[0120] Methods for constructing a knowledge base for fixed-value adjustment strategies: The cloud platform provides statistics on the protection malfunction rate and leakage rate of each device under different protection levels: When the false alarm rate of a certain gradient exceeds 5%, the setpoint corresponding to that gradient is automatically increased by 5%. When the leakage rate of a certain gradient exceeds 1%, the setpoint corresponding to that gradient is automatically reduced by 3%. The fixed-value adjustment strategy knowledge base is updated quarterly to ensure that the strategy matches the actual operating data.

[0121] Edge-side smooth switching mechanism: Edge computing units employ a dual-caching mechanism to achieve smooth switching of knowledge base updates: The edge side maintains two caches simultaneously: the current runtime library and the library to be updated. When updating data is distributed from the cloud, it is first written to the "database to be updated" and its integrity is verified. After the verification is passed, during the idle time when the circuit breaker is in the closed state and has no disconnection action, the library to be updated will be switched to the current running library. During the switchover, the original diagnostic and protection functions remain unaffected, ensuring the continuity of system operation.

[0122] The cloud platform releases updates monthly, but emergency updates can be released in real time via manual triggering.

[0123] To verify the technical effect of the present invention, a simulated operation test was conducted on a certain model of 10kV vacuum circuit breaker. The test conditions were as follows: circuit breaker rated current: 1250A; factory overload protection setting: Total number of disconnections: 1000 times, including 50 short-circuit disconnections, 200 overload disconnections, and 750 normal operation disconnections; Comparison group: using the traditional unified cumulative wear assessment method + fixed overload protection setting.

[0124] Comparison of accuracy in assessing contact electrical wear:

[0125] The test results show that the present invention reduces the relative error of contact electrical wear assessment from 38.5% to 2.9% by weighting the breakage type and correcting the arcing time, which significantly improves the assessment accuracy.

[0126] Comparison of protection setting matching effects: After 1000 cumulative interruptions, the system of this invention calculated the remaining current-carrying capacity of the contact to be 875A (0.7). The overload protection setting will be automatically lowered to level 3. Then, a simulated overload test was conducted: When the load current rises to 1450A, the protection device of the present invention will activate within 2 seconds; The protection device in the control group remained in operation at the set value of 1562.5A and did not activate. The contact temperature continued to rise to 185°C, exceeding the upper limit of the allowable temperature.

[0127] The test results show that the present invention achieves dynamic matching between the protection action characteristics and the actual current carrying capacity of the contacts, effectively avoiding the protection mismatch problem caused by contact wear.

[0128] Edge-cloud collaborative optimization effect: After three months of cloud-based data aggregation and model optimization, the accuracy of contact wear assessment for the same model of equipment has been further improved to 1.2%, and the protection malfunction rate has been reduced from the initial 2.1% to 0.3%, verifying the continuous optimization effect of group big data on the performance of individual equipment.

[0129] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. An integrated switchgear with intelligent diagnostic function, characterized in that, The device is based on an integrated switch system with intelligent diagnostic capabilities, including: The circuit breaker tripping event type identification module collects the tripping current waveform each time the circuit breaker trips. By analyzing the characteristics of the tripping current waveform, it automatically identifies the tripping type of the tripping operation. The tripping types include short-circuit tripping, overload tripping, and normal operation tripping. The break type weighted wear accumulation module presets wear weight coefficients for each break type. After each break action, it selects the corresponding wear weight coefficient according to the break type output by the break event type identification module, calculates the effective contribution of this break action to the contact electrical wear, and accumulates the effective contribution to the contact cumulative electrical wear register. The contact remaining current carrying capacity estimation module determines the contact remaining current carrying capacity based on the cumulative electrical wear value in the contact cumulative electrical wear register and in combination with the preset contact electrical wear characteristic curve. The overload protection setting gradient adjustment module divides the overload protection action setting into multiple gradient levels and adjusts them in stages according to the remaining current carrying capacity of the contacts. For each preset decrease in the remaining current carrying capacity of the contacts, the overload protection action setting is lowered by one level. The setting value sending module sends the overload protection action setting value after gradient adjustment to the protection device to update the overload protection action characteristics of the protection device.

2. The integrated switchgear with intelligent diagnostic function according to claim 1, characterized in that, When the weighted wear accumulation module for the breaking type calculates the effective contribution of the breaking action to the contact wear, it first obtains the breaking current waveform corresponding to the breaking action, calculates the Joule integral value of the breaking current during the breaking process, and then multiplies the Joule integral value with the wear weight coefficient corresponding to the breaking type to obtain the effective contribution of the breaking action. The Joule integral of the breaking current during the breaking process Calculate using the following formula: ； in, This represents the instantaneous value of the current as it changes over time during the breaking process. The starting time of the segmentation, The end time of the segmentation. Effective contribution of this segmentation action Calculate using the following formula: ； in, This is the Joule integral of the breaking current during the breaking process. The wear weighting coefficient corresponds to the breakage type. This represents the effective contribution of this disconnection action to the contact wear.

3. The integrated switchgear with intelligent diagnostic function according to claim 1, characterized in that, The weighted wear accumulation module for the break type further incorporates the arcing time correction factor when calculating the effective contribution of this break action. The arcing time correction factor is related to the arcing duration detected in this disconnection action. The longer the arcing duration, the larger the value of the arcing time correction factor. Effective contribution of this shunt action after taking into account the arcing time correction factor Calculate using the following formula: ； in, This refers to the duration of arcing detected during this interruption action. This is the arc time correction factor function. The effective contribution without arc time correction. This is the effective contribution of this disconnection action after taking into account the arcing time correction factor.

4. An integrated switchgear with intelligent diagnostic function according to claim 1, characterized in that, Before determining the remaining current carrying capacity of the contact based on the cumulative electrical wear value, the contact remaining current carrying capacity estimation module also detects whether the cumulative electrical wear value has reached the wear warning threshold. When the cumulative electrical wear value reaches the wear warning threshold, the contact remaining current carrying capacity estimation module generates a contact replacement warning signal.

5. An integrated switchgear with intelligent diagnostic function according to claim 1, characterized in that, When the overload protection setting gradient adjustment module divides the overload protection action setting into multiple gradient levels for graded downward adjustment, the higher the remaining current carrying capacity of the contacts, the closer the overload protection action setting is to the factory setting value; the lower the remaining current carrying capacity of the contacts, the greater the downward adjustment of the overload protection action setting. The downward adjustment of the overload protection action setting shall not exceed the preset upper limit.

6. An integrated switchgear with intelligent diagnostic function according to claim 5, characterized in that, The overload protection setpoint gradient adjustment module is also equipped with an adjustment strategy verification function; After each overload protection action setting is lowered, the overload protection setting gradient adjustment module monitors the load current and protection action records within the subsequent preset time window. If a malfunction occurs due to a reduction in the setpoint within the preset time window, the overload protection setpoint gradient adjustment module will automatically restore the overload protection action setpoint to the value before the adjustment.

7. An integrated switchgear with intelligent diagnostic function according to claim 1, characterized in that, It also includes edge computing units and communication modules; The interruption event type identification module, interruption type weighted wear accumulation module, contact remaining current carrying capacity estimation module, overload protection setpoint gradient adjustment module, and setpoint distribution module are all deployed in the edge computing unit; The communication module is used to upload diagnostic data and setpoint adjustment records from the edge computing unit to the cloud platform.

8. An integrated switchgear with intelligent diagnostic function according to claim 7, characterized in that, It also includes a cloud-based data aggregation and trend analysis module, which aggregates historical data on cumulative contact wear and overload protection setting adjustment records uploaded by multiple sets of switchgear, and establishes a library of typical contact wear curves and a knowledge base of setting adjustment strategies according to equipment model and operating environment.

9. An integrated switchgear with intelligent diagnostic function according to claim 8, characterized in that, The cloud-based data aggregation and trend analysis module will also periodically distribute the established typical contact wear curve library and setpoint adjustment strategy knowledge base to the edge computing units of each complete set of switchgear, in order to update the preset contact wear characteristic curves and the gradient division mapping relationship of the overload protection setpoint gradient adjustment module.

10. An integrated switchgear with intelligent diagnostic function according to claim 1, characterized in that, The contact electrical wear characteristic curve is a curve showing the relationship between the cumulative electrical wear value of the contact and the remaining current carrying capacity of the contact, obtained through experimental calibration. The contact remaining current carrying capacity estimation module takes the cumulative electrical wear value in the contact cumulative electrical wear register as input, and outputs the corresponding contact remaining current carrying capacity by querying the contact electrical wear characteristic curve or by interpolating based on the contact electrical wear characteristic curve. Cumulative electrical wear value of contacts The cumulative sum of the effective contributions of each segmentation action is calculated using the following formula: ； in, For the first The effective contribution of the second interruption action after arc time correction. For the first The wear weight coefficient corresponding to the type of breakage in the secondary breakage action. For the first The Joule integral value of the next segmentation action. For the first The arc time correction factor function value for the second interruption action. This represents the total number of tripping operations of the circuit breaker since it was put into operation or the last contact replacement. This represents the cumulative electrical wear value of the contacts. The contact residual current capacity estimation module is based on the cumulative electrical wear value. Determine the remaining current carrying capacity of the contacts The calculation relationship is expressed as follows: ； in, This refers to the remaining current-carrying capacity of the contacts. The mapping function characterized by the contact electrical wear characteristic curve; when When it is zero Equal to the initial rated current capacity, when When the end-of-life threshold is reached Reduce to the preset minimum allowed value.

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