A method for arc fault fast suppression and isolation of power distribution cabinet

Abstract

The application discloses a kind of power distribution cabinet arc light fault fast inhibition isolation method, belong to power distribution cabinet fault protection technical field.The method includes: synchronous acquisition power distribution cabinet main circuit current signal, current variation characteristic quantity, high-frequency voltage disturbance signal and light radiation signal;Build the arc light risk comprehensive discriminant model of multi-parameter weighted fusion, through normalization processing, characteristic quantity calculation and online weight update, real-time evaluation arc light formation precursor;The evaluation value is compared with adaptive load threshold, accurately determine the early stage of arc light;Trigger solid-state bypass energy limiting module to build low-impedance bypass, realize main circuit current transfer;Through the energy absorption unit of capacitor buffer and resistance dissipation dissipates current energy, so that arc light current is reduced to below maintaining current to realize arc extinguishing, trigger secondary forced arc extinguishing under extreme working conditions.The application upgrades protection logic to predictive active energy limiting, completes energy inhibition before mechanical breaking, greatly improves the timeliness and reliability of power distribution cabinet arc light fault protection.

Description

Technical Field

[0001] This invention relates to the field of power distribution cabinet fault protection technology, specifically to a method for rapid suppression and isolation of arc faults in power distribution cabinets. Background Technology

[0002] As the core equipment for power distribution, circuit control, and power protection in power systems, distribution cabinets are widely used in industrial plants, commercial buildings, municipal facilities, and residential communities. Their operating environment is complex, and they are subject to long-term effects such as load fluctuations, changes in ambient temperature and humidity, dust corrosion, and equipment aging. They are prone to arcing faults due to insulation damage, loose conductor contacts, foreign objects entering live gaps, or operational errors.

[0003] When an arc fault occurs, it instantly generates high-temperature plasma, accompanied by intense light radiation, sudden current changes, and high-frequency voltage disturbances, releasing enormous energy within microseconds to milliseconds. Current arc fault protection technologies generally employ a passive protection mode based on a dual criterion of "arc fault + current," meaning that the mechanical circuit breaker is only triggered to trip after the arc fault has fully formed. However, mechanical circuit breakers have an inherent operating delay; before they complete the tripping action, the arc energy has already been released, easily causing cabinet ablation, busbar melting, and even serious safety accidents such as fires and explosions. This can also lead to widespread power outages, severely impacting production and daily life. Furthermore, traditional protection methods do not identify or intervene in the precursors of arc fault formation and lack proactive energy suppression measures, making them ill-suited to the high requirements of modern power distribution systems for power supply reliability and safety. Summary of the Invention

[0004] The purpose of this invention is to provide a method for rapid suppression and isolation of arc faults in power distribution cabinets, so as to solve the existing technical defects such as delayed response, passive protection, and lack of energy suppression.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A method for rapid suppression and isolation of arcing faults in a power distribution cabinet includes the following steps: 1. Perform synchronous acquisition of multiple physical quantities on the main circuit of the power distribution cabinet. The acquired physical quantities include current signals, current change characteristics, high-frequency voltage disturbance signals, and optical radiation signals to ensure the time consistency and integrity of the acquired data. 2. Based on the collected multi-physical quantities, a comprehensive judgment model for arc light risk is constructed. Through normalization processing, multi-parameter weighted fusion, and online learning mechanism, accurate real-time assessment of the precursors to arc light formation is achieved. 3. Compare the real-time assessment results of the arc risk comprehensive judgment model with the adaptively adjusted preset risk conditions, and accurately identify the precursors or early stages of arc formation based on clear numerical judgment logic; 4. After determining that the arc is in the precursor or early stage of formation, immediately trigger the solid-state bypass energy limiting module to construct a low-impedance bypass branch, so that the main circuit current of the distribution cabinet is quickly transferred to the bypass branch, thereby reducing the energy supply of the arc channel from the source. 5. By using the energy absorption unit connected in series with the bypass branch, the current transferred to the bypass branch is buffered and dissipated, gradually reducing the arc current until it is lower than the arc sustaining current, thereby achieving active arc extinguishing. 6. After completing the active power limiting and extinguishing operation for arcing, the mechanical isolation device is triggered to completely physically disconnect the main circuit of the distribution cabinet with arcing fault, thereby achieving complete isolation between the faulty circuit and the normal circuit. 7. Accurately locate the fault area of ​​the power distribution cabinet, and record the entire process protection information of this arc flash fault to provide data support for subsequent fault investigation, equipment maintenance and model optimization.

[0006] The arc risk comprehensive discrimination model is based on multi-parameter weighted fusion, introducing current change acceleration features to improve early identification sensitivity. The weights of each parameter are determined through training with historical samples and dynamically updated using an online learning mechanism to ensure the model's discrimination accuracy under different operating conditions. The preset risk conditions are based on an adaptive threshold constructed using the real-time load rate of the main circuit of the distribution cabinet, ensuring that the protection triggering logic matches the actual operating state of the equipment.

[0007] The solid-state bypass energy limiting module uses a power semiconductor switch array as its core execution component, possessing millisecond-level fast response capability. The equivalent impedance of the bypass branch it constructs is strictly less than the equivalent impedance of the main circuit, and its trigger response time is earlier than the physical disconnection time of the mechanical isolation device, ensuring that the current transfer operation is completed before mechanical isolation. The energy absorption unit adopts a composite structure of "capacitor buffer + resistor dissipation," which can achieve buffering of inrush current and efficient dissipation of electrical energy.

[0008] This method adds a real-time assessment of arc energy during the energy dissipation process. When the energy released by the arc reaches the preset safety limit, a secondary forced arc extinguishing control is immediately triggered to further ensure the arc extinguishing effect. At the same time, the recording of protection information throughout the process realizes closed-loop management for fault tracing.

[0009] The present invention has the following beneficial effects: This invention breaks through the passive mode of traditional arc flash protection, which involves "fault-based disconnection," and constructs a full-process active protection system encompassing "early warning identification, active power limiting, and physical isolation." Through simultaneous acquisition of multiple physical quantities and an intelligent risk assessment model, it achieves accurate identification of arc flash formation in its early stages, significantly advancing the protection intervention point. By leveraging the synergistic effect of the solid-state bypass energy limiting module and the energy absorption unit, arc energy is transferred and dissipated before mechanical isolation, fundamentally preventing equipment damage caused by excessive arc energy release. The tiered protection logic ensures both rapid fault suppression and thorough fault isolation, effectively preventing fault propagation. The overall technical solution, through its closed-loop logic design, significantly improves the response efficiency and reliability of the distribution cabinet's arc fault protection, comprehensively ensuring the safety of the distribution cabinet equipment and the stable power supply of the power system. Attached Figure Description

[0010] Figure 1 The diagram illustrates the specific steps of the method of the present invention.

[0011] Figure 2 This is a wireframe diagram of the internal structure of the solid-state bypass power limiting module in this invention.

[0012] Figure 3 This is a wireframe diagram illustrating the current transfer principle between the main circuit and the bypass branch in this invention.

[0013] Figure 4 This is a wireframe diagram of the energy absorption unit structure and energy suppression logic in this invention. Detailed Implementation

[0014] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0015] refer to Figures 1-4 As shown, a method for rapid suppression and isolation of arc flash faults in power distribution cabinets is executed according to a continuous process of "multi-physical quantity acquisition → risk assessment → active energy limiting → energy dissipation → physical isolation → fault locking", specifically including the following steps: Step 1: Synchronous acquisition of multiple physical quantities in the main circuit of the power distribution cabinet The multi-physical quantity synchronous acquisition module serves as the data input terminal for the entire protection method. It employs an integrated synchronous acquisition sensor group to acquire electrical and optical physical quantities of the main circuit of the distribution cabinet with high synchronization and high precision. The core physical quantities acquired include four categories: current signals of each phase of the main circuit of the distribution cabinet, current change characteristics calculated based on current signals, high-frequency voltage disturbance signals on the bus side, and optical radiation signals inside the distribution cabinet.

[0016] The current signal is acquired through a through-hole Hall current sensor, enabling non-contact measurement and avoiding disruption to the normal operation of the main circuit. High-frequency voltage disturbance signals are acquired through a high-frequency voltage transformer, specifically capturing high-frequency voltage oscillations caused by insulation breakdown in the early stages of arc formation. Optical radiation signals are acquired through an ultraviolet-visible composite optical sensor, accurately identifying the unique spectral characteristics of the arc and distinguishing it from ordinary lighting and heat generated by equipment. Current change characteristics are derived physical quantities, calculated by the built-in computing unit of the acquisition module based on real-time current signals. These core quantities include the rate of change of current and the acceleration of current change, used to capture the sudden current changes in the early stages of arc formation.

[0017] To ensure the accuracy of subsequent model calculations, the sampling frequency of all sensors is uniformly set, and timestamp alignment is achieved through high-precision clock synchronization technology, controlling the time synchronization error of the acquired data to the microsecond level. The acquired raw data of multiple physical quantities are converted from analog to digital and transmitted in real time to the data processing and model calculation module in digital signal form, providing a complete and reliable data foundation for arc risk identification.

[0018] Step 2: Construct a comprehensive arc risk discrimination model and achieve real-time assessment. After receiving the raw multi-physical quantity data transmitted in step 1, the data processing and model calculation module completes the real-time assessment of the precursors to arc formation through the constructed arc risk comprehensive discrimination model. This model uses multi-parameter weighted fusion as its core logic and achieves accurate output of the assessment value through a four-level calculation process: "data normalization → feature quantity calculation → weighted fusion → weight update." The specific execution process is as follows: Multi-physical quantity parameter normalization processing Because different physical quantities have significant differences in dimensions and orders of magnitude, direct fusion would lead to an imbalance in weight allocation. Therefore, the parameters of each physical quantity are first normalized, mapping all parameters to the [0,1] interval to eliminate the influence of dimensions. The normalization calculation uses the extreme value normalization method, and the formula is as follows: , In the formula, For the first Normalized values ​​of each physical quantity parameter For the first Real-time acquired values ​​of each physical quantity parameter. For the first The historical minimum value of each physical quantity parameter For the first The historical maximum value of a physical quantity parameter.

[0019] The data processing module pre-stores historical extreme value data for each physical quantity and updates it regularly to ensure the effectiveness of the normalization process. For all parameters involved in the fusion, such as current variation characteristics, high-frequency voltage disturbance signals, and optical radiation signals, normalization is performed according to the above formula to obtain a standardized parameter dataset.

[0020] Calculation of characteristic quantity of acceleration due to change of current To improve the sensitivity of identifying precursors to arc formation, the acceleration due to current change is used as a core feature in multi-parameter weighted fusion. This feature is calculated from the current signals acquired at two consecutive synchronous acquisition moments, and can accurately capture the rapid change trend of current in the early stage of arc formation. The calculation formula is as follows: , In the formula, The acceleration characteristic quantity of the change in current is expressed in A / ms. Change in current, in amperes (A). This is a time-varying quantity, expressed in milliseconds (ms). for The current signal value collected at all times, for The current signal value collected at all times, , These are two consecutive synchronous acquisition moments, and > .

[0021] The calculated current change acceleration characteristic quantity is processed according to the normalization formula in step 2.1 and then included as an independent parameter in the subsequent weighted fusion calculation.

[0022] Multi-parameter weighted fusion calculation of arc risk assessment value After normalizing all physical parameters, a multi-parameter weighted fusion algorithm is used to calculate the real-time arc risk assessment value. The core calculation formula is as follows: , In the formula, This represents the arc risk assessment value output by the arc risk comprehensive discrimination model, where n is the total number of physical quantity parameters involved in the fusion. For the first The weighting coefficients of each physical quantity parameter satisfy the following conditions: =1, ∈(0,1), ∈[0,1], the magnitude of the weight coefficient reflects the contribution of the corresponding physical quantity to arc fault identification; For the first Normalized values ​​of physical quantity parameters.

[0023] Training and online dynamic updating of weight coefficients Weighting coefficients of each physical quantity parameter First, offline training was completed using a historical arc flash sample set. The historical sample set covers arc flash fault data and normal operation data of the distribution cabinet under different load conditions, environmental conditions, and fault types. The sample set was trained using machine learning algorithms to obtain an initial weight coefficient allocation scheme, so that the model can achieve optimal accuracy in identifying arc flash faults.

[0024] To adapt to dynamic changes in the operating environment and load status of the distribution cabinet, the weighting coefficients are updated in real time through an online learning mechanism. The update calculation formula is as follows: In the formula, For the (t+1)th update cycle, the first... Weighting coefficients for each physical quantity parameter For the t-th update cycle, the th Weighting coefficients for each physical quantity parameter For the first The weight correction amount for each physical quantity parameter.

[0025] The data processing module calculates the weight correction based on newly acquired arc light sample data, environmental parameter change data, and load fluctuation data. When a certain physical quantity shows higher sensitivity in recent fault identification, its weight correction is positive, and the weight coefficient increases accordingly; conversely, the weight coefficient decreases. The online update cycle can be flexibly set according to the operating conditions of the distribution cabinet to ensure that the model is always adapted to the actual operating state.

[0026] The data processing and model calculation module performs continuous calculations on the real-time collected multi-physical quantity data according to the above process. After each data collection is completed, a real-time arc risk assessment value R is output, continuously completing the real-time assessment of the precursors to arc formation.

[0027] Step 3: Determining the Arc Formation Stage After receiving the real-time arc risk assessment value R from the data processing and model calculation module, the control execution module, in conjunction with preset adaptive risk conditions, accurately determines the arc formation stage. The core of the preset risk conditions is the adaptive arc risk threshold R0. This threshold is not a fixed value but is dynamically adjusted based on the real-time load status of the main circuit of the distribution cabinet. This ensures the rationality and accuracy of the protection triggering logic under different operating conditions such as light load and heavy load. The formula for calculating the adaptive threshold is: In the formula, The adaptive arc risk threshold for the arc risk comprehensive discrimination model. The load condition correction factor is determined by the equipment type, rated capacity, and operating conditions of the distribution cabinet, and is a fixed calibration value; L is the real-time load rate of the main circuit of the distribution cabinet, calculated as follows: , ,in The real-time load current of the main circuit collected in step 1. This is the rated load current of the main circuit of the distribution cabinet.

[0028] The judgment logic employs an explicit numerical comparison method, whereby the control execution module compares the real-time arc risk assessment value R with the adaptive arc risk threshold. Perform time-by-time comparisons, when the conditions are met ≥ Upon detection, the system immediately determines whether the arc is in its precursor or early stage. The determination result is transmitted in real-time to the main control unit of the control execution module in the form of digital commands, triggering a series of subsequent protection actions; if... < If the signal is received, the distribution cabinet is determined to be in normal operating condition, and no protection action is triggered; only risk monitoring continues.

[0029] Step 4: Trigger the solid-state bypass power limiting module to achieve current transfer. After receiving the judgment command that "the arc is in the precursor or early stage of formation", the main control unit of the control execution module outputs a trigger signal within microseconds to start the solid-state bypass power limiting module and perform current transfer operation.

[0030] The solid-state bypass energy limiting module is the core execution component, installed on the bus side of the main circuit of the distribution cabinet, forming a parallel structure with the main circuit. Its core components include a power semiconductor switch array, a damping branch, a drive circuit, and a protection circuit. The power semiconductor switch array uses a bridge circuit composed of insulated-gate bipolar transistors (IGBTs) and fast recovery diodes, featuring low on-resistance and fast switching speed. The damping branch consists of an inductor and a capacitor connected in series, used to suppress voltage spikes generated during current transfer and protect the power semiconductor devices.

[0031] After receiving the trigger signal from the control execution module, the drive circuit immediately turns on the power semiconductor switch array, enabling the solid-state bypass energy limiting module to quickly establish a bypass branch connected in parallel with the main circuit of the distribution cabinet. The equivalent impedance of the bypass branch... Through component selection and circuit design, the impedance is strictly controlled to be less than the equivalent impedance of the main circuit of the distribution cabinet. That is, satisfying According to the principle of current division in a circuit, in a parallel circuit, the current will preferentially flow to the branch with lower impedance. Therefore, the current in the main circuit of the distribution cabinet will quickly transfer to the bypass branch, and the power supply current of the arc channel will decrease significantly, thus achieving a direct and rapid reduction in the energy supply to the arc channel.

[0032] To ensure that the current transfer operation is completed before the mechanical isolation action, the trigger response time of the solid-state bypass power limiting module is... The time from receiving the trigger signal to the bypass branch being fully connected is strictly designed to be less than the physical disconnection time of the mechanical isolation device. That is, satisfying This timing design logic ensures that arc energy is effectively suppressed before the mechanical circuit breaker performs its disconnection action, fundamentally avoiding the defect of "arc ignition first, tripping later" in traditional protection methods.

[0033] Step 5: The energy absorption unit achieves current buffering and dissipation, as well as arc extinguishing. While the bypass branch constructed by the solid-state bypass energy limiting module is turned on and the main circuit current is transferred to the bypass branch, the energy absorption unit connected in series with the bypass branch is put into operation simultaneously. Through the "buffering-dissipation" collaborative mechanism, the energy processing of the transferred current is completed, and the active extinction of the arc is finally achieved.

[0034] The energy absorption unit adopts a composite topology of "capacitor buffer structure + resistor dissipation structure". The capacitor buffer structure consists of a large-capacity energy storage capacitor, and the resistor dissipation structure consists of a high-power alloy resistor. The two structures are connected in series through a unidirectional conducting device to form an orderly energy processing flow. Its core working logic is as follows: When the inrush current of the main circuit is first transferred to the bypass branch, the capacitor buffer structure first absorbs and buffers the inrush current, converting electrical energy into electric field energy and storing it in the capacitor, effectively reducing the instantaneous peak value of the current and preventing the large current from directly impacting the subsequent circuit. When the voltage across the capacitor reaches a preset value, the unidirectional conducting device turns on, and the electrical energy stored in the capacitor is released through the resistor dissipation structure. The alloy resistor converts the electrical energy into heat energy and dissipates it into the environment through the heat dissipation structure, achieving efficient dissipation of electrical energy.

[0035] The energy dissipated by the energy absorption unit for the bypass branch current is calculated in real time using the following formula: In the formula, The energy dissipated by the bypass branch current in the energy absorption unit is expressed in J. This is the moment when the current begins to shift to the bypass branch (i.e., the moment when the solid-state bypass power limiting module is turned on). The moment when the arc current drops below the sustaining current. Let be the instantaneous value of the bypass branch current at time t. This is the equivalent dissipation resistance of the energy absorption unit.

[0036] Under the continuous effect of capacitor buffering and resistive dissipation, the current in the bypass branch gradually decreases, and the power supply current of the arc channel in the main circuit of the distribution cabinet decreases synchronously and continuously. When the arc current drops below the arc sustaining current, the arc loses its continuous energy supply and cannot maintain the plasma state, thus achieving natural and rapid extinguishing.

[0037] During the aforementioned energy dissipation process, the control execution module also simultaneously performs a real-time assessment of arc energy to address arc suppression under extreme conditions and ensure effective arc extinguishing. The real-time energy released by the arc is calculated using the following formula: In the formula, The real-time energy released by the arc light. The moment when the arc light risk comprehensive discrimination model determines whether the arc light is in the precursor or early stage of formation is given by t, where t is the current moment of real-time assessment of the arc light energy. for The instantaneous value of the arc current at time . The equivalent resistance of the arc channel is calibrated in advance based on the operating conditions and fault types of the distribution cabinet.

[0038] The control execution module continuously compares the real-time calculated arc energy W with the preset arc energy safety limit W0. ≥ Upon activation, the secondary forced arc extinction control is immediately triggered. The core actions of the secondary forced arc extinction control include: increasing the dissipation power of the energy absorption unit (achieved by activating the backup resistor dissipation branch) and improving the shunting efficiency of the solid-state bypass power limiting module (achieved by optimizing the conduction state of the power semiconductor switch array). Through these dual enhancement methods, the arc current decay rate is forcibly accelerated, ensuring that the arc is extinguished in a very short time and eliminating the risk of excessive arc energy release under extreme operating conditions.

[0039] Step 6: Trigger the mechanical isolation device to physically disconnect the fault circuit. Once step 5 completes the active arc extinguishing operation and the control execution module confirms that the arc current has been continuously lower than the arc sustaining current, it immediately sends a trigger command to the mechanical isolation device to execute the physical disconnection operation of the fault circuit.

[0040] The mechanical isolation device uses a dedicated intelligent vacuum circuit breaker for distribution cabinets, characterized by strong breaking capacity and good insulation performance. It is connected in series with the main circuit of the distribution cabinet and is the core component for achieving complete isolation between the faulty circuit and the normal power supply circuit. After receiving the trigger command from the control execution module, the intelligent vacuum circuit breaker's operating mechanism drives the circuit breaker contacts to quickly disconnect. Under the action of the vacuum interrupter, the main circuit is physically disconnected, completely isolating the circuit with the arc fault from the other normal circuits in the distribution cabinet.

[0041] The execution of this physical isolation operation achieved two core objectives: first, to completely cut off the power supply to the faulty circuit and eliminate the possibility of arc fault recurrence; and second, to prevent the impact of the fault from spreading to other power distribution units in the distribution cabinet, ensuring the normal power supply to non-faulty circuits and significantly improving the power supply reliability of the power system.

[0042] Step 7: Fault Zone Locator and Protection Information Recording While the mechanical isolation device physically disconnects the fault circuit, the control execution module simultaneously sends a command to the fault recording and locking module to initiate the fault area locking and protection information recording process, thereby achieving fault tracing and closed-loop management.

[0043] Precise location of the fault area The distribution cabinet is equipped with a zoned positioning system based on circuit divisions, each corresponding one-to-one with the primary circuit topology of the cabinet. After receiving control commands, the fault recording and locking module, based on the spatial distribution characteristics of the current and light radiation signals collected in step 1, and combined with the disconnection position of the mechanical isolation device, accurately determines the specific circuit, switchgear bay, and busbar area where the fault occurred. The fault area is then graphically marked through the distribution cabinet's local display unit and remote monitoring platform, achieving visual locking of the fault area. Simultaneously, the fault area door lock of the distribution cabinet automatically locks to prevent personnel from accidentally entering the fault area, improving the safety of the maintenance process.

[0044] Full-process protection information recording The protection information recording module uses industrial-grade storage chips, ensuring data integrity even when power is off. It collects and stores complete information about the entire arc fault process, from occurrence to resolution, according to a preset recording format. The core recorded information includes: raw data from the multi-physical quantity acquisition module (including time-series curves of current, voltage, and optical radiation signals); calculation results from the data processing module (including normalized values ​​of each physical quantity and curves showing changes in arc risk assessment values); the fault determination time; the trigger time and conduction status of the solid-state bypass energy limiting module; energy dissipation data from the energy absorption unit; the disconnection time of the mechanical isolation device; the arc energy change process; the execution status of the secondary forced arc extinguishing control (if applicable); and the fault location information.

[0045] The recorded protection information can be uploaded to the upper-level monitoring system of the distribution cabinet in real time via the industrial communication bus, or exported via the local interface. This data provides a complete and detailed basis for subsequent fault cause analysis, equipment maintenance plan formulation, and optimization and upgrading of the arc flash risk discrimination model, enabling the arc flash protection of the distribution cabinet to form a closed-loop system of "identification-intervention-recording-optimization" and continuously improve protection performance; The core working principle of this method revolves around a dual logical closed loop of "accurate early warning identification" and "step-by-step active energy control." It relies on multi-module collaboration to achieve fully automated protection from fault prediction to complete isolation. The specific principle can be summarized into three core levels: The principle of multi-dimensional fusion for early warning identification: By simultaneously collecting current, current change acceleration, high-frequency voltage disturbance, and optical radiation signals, a multi-physical quantity dataset covering electrical and optical characteristics is constructed. First, extreme value normalization is used to eliminate dimensional differences. Then, a weighted fusion algorithm is used to calculate the arc risk assessment value. Combined with an adaptive threshold judgment logic based on real-time load rate, accurate and real-time identification of early warning signs and early stages of arc formation is achieved, overcoming the limitation of traditional protection systems that only respond after a fault occurs. Simultaneously, an online learning mechanism dynamically updates parameter weights, enabling the identification model to continuously adapt to changes in the operating conditions of the distribution cabinet, ensuring accurate judgment.

[0046] The active energy control principle of first limiting energy and then isolating is as follows: After determining the early state of the arc, the solid-state bypass energy limiting module is triggered first. Utilizing the principle of "low-impedance bypass current shunting," the main circuit current is rapidly transferred to the bypass branch, cutting off the energy supply to the arc channel at its source. Then, through a composite energy absorption structure of "capacitor buffer + resistor dissipation," the impact energy of the transferred current is buffered, stored, and efficiently dissipated, gradually reducing the arc current below the sustaining current, thus achieving active arc extinguishing. Under extreme conditions, a secondary forced arc extinguishing is triggered by real-time assessment of the arc energy, further enhancing the energy control effect. This process strictly follows the timing logic of "solid-state response takes precedence over mechanical action," ensuring that energy suppression is completed before mechanical isolation.

[0047] The isolation and recording principle of closed-loop tracing: After the arc is successfully extinguished, the mechanical isolation device is triggered to physically disconnect the fault circuit, completely eliminating the risk of fault re-ignition and spread; at the same time, based on the spatial distribution characteristics and action node information of the collected data, the fault area is accurately located, and the electrical data, action sequence and model calculation results of the entire fault process are completely recorded, forming a complete closed loop of "identification-intervention-isolation-tracing", which not only ensures the safe operation of the distribution cabinet, but also provides core data support for subsequent equipment maintenance and model optimization.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for rapid suppression and isolation of arc flash faults in a power distribution cabinet, characterized in that, Includes the following steps: S1. Synchronously acquire multiple physical quantities of the main circuit of the power distribution cabinet, including current signal, current change characteristic quantity, high-frequency voltage disturbance signal, and optical radiation signal. S2. Construct a comprehensive arc risk discrimination model based on the collected multi-physical quantities, and use this model to evaluate the precursors of arc formation in the main circuit of the distribution cabinet in real time; S3. Compare the real-time evaluation results of the arc risk comprehensive judgment model with the preset risk conditions. If the evaluation results meet the preset risk conditions, it is determined that the arc of the main circuit of the distribution cabinet is in the precursor or early stage of formation. S4. After determining that the arc is in the precursor or early stage of formation, the solid-state bypass energy limiting module is triggered to transfer the current of the main circuit of the distribution cabinet to the bypass branch, thereby reducing the energy of the arc channel. S5. The current transferred to the bypass branch is buffered and dissipated by the energy absorption unit, so that the arc current is reduced to below the arc maintenance current, and the arc is extinguished. S6. After completing the active arc flash power limiting operation, trigger the mechanical isolation device to physically disconnect the main circuit of the distribution cabinet with arc flash fault. S7. Lock the arc fault zone of the distribution cabinet and record the protection information of the arc fault.

2. The method for rapid suppression and isolation of arc faults in a distribution cabinet according to claim 1, characterized in that, The arc risk comprehensive discrimination model is constructed based on a multi-parameter weighted fusion mechanism. The arc risk assessment value of the arc risk comprehensive discrimination model is calculated as follows: ， In the formula, This represents the arc risk assessment value output by the arc risk comprehensive discrimination model, where n is the total number of physical quantity parameters involved in the fusion. For the first Weighting coefficients for each physical quantity parameter For the first The normalized values ​​of each physical quantity parameter, and satisfying =1, ∈(0,1), ∈[0,1].

3. The method for rapid suppression and isolation of arc flash faults in a distribution cabinet according to claim 1, characterized in that, The current change characteristic quantity includes the current change acceleration characteristic quantity, and the formula for calculating the current change acceleration characteristic quantity is: ， In the formula, The acceleration characteristic quantity of the change in current is expressed in A / ms. Change in current, in amperes (A). This is a time-varying quantity, expressed in milliseconds (ms). for The current signal value collected at all times, for The current signal value collected at all times, , These are two consecutive synchronous acquisition moments, and > .

4. The method for rapid suppression and isolation of arc flash faults in a distribution cabinet according to claim 1, characterized in that, The preset risk conditions are adaptively adjusted based on the real-time load status of the main circuit of the distribution cabinet. The arc risk threshold of the preset risk conditions is calculated as follows: ， In the formula, The adaptive arc risk threshold for the arc risk comprehensive discrimination model. The load condition correction factor is determined by the operating conditions of the main circuit of the distribution cabinet, where L is the real-time load rate of the main circuit of the distribution cabinet. , This is the real-time load current of the main circuit of the distribution cabinet. This is the rated load current of the main circuit of the distribution cabinet.

5. The method for rapid suppression and isolation of arc flash faults in a distribution cabinet according to claim 1, characterized in that, The trigger response time of the solid-state bypass power limiting module satisfy , The physical disconnection time of the mechanical isolation device, and the equivalent impedance of the bypass branch constructed by the solid-state bypass energy limiting module. satisfy , This is the equivalent impedance of the main circuit of the distribution cabinet.

6. The method for rapid suppression and isolation of arc flash faults in a distribution cabinet according to claim 1, characterized in that, The calculation formula for normalizing each physical quantity parameter in step S2 is as follows: ， In the formula, For the first Normalized values ​​of each physical quantity parameter For the first Real-time acquired values ​​of each physical quantity parameter. For the first The historical minimum value of each physical quantity parameter For the first The historical maximum value of a physical quantity parameter.

7. The method for rapid suppression and isolation of arc faults in a distribution cabinet according to claim 2, characterized in that, Weighting coefficients of each physical quantity parameter The weighting coefficients were determined through training with historical arc light samples. The weight coefficients are dynamically updated via an online learning mechanism, and the dynamic update calculation formula is as follows: In the formula, For the (t+1)th update cycle, the first... Weighting coefficients for each physical quantity parameter For the t-th update cycle, the th Weighting coefficients for each physical quantity parameter For the first The weight correction of each physical quantity parameter is calculated from the newly acquired arc light sample data and the environmental load change data.

8. The method for rapid suppression and isolation of arc flash faults in a distribution cabinet according to claim 5, characterized in that, A real-time arc energy evaluation step is also set between step S4 and step S5. The real-time calculation formula for arc energy is: ， In the formula, This represents the real-time energy released by the arc, measured in J. To determine whether an arc is in its precursor or early stage in order to establish a comprehensive risk assessment model for arc formation. For the current moment of real-time assessment of arc energy, (t) is The instantaneous value of the arc current at time t, in amperes (A). This is the equivalent resistance of the arc light channel, measured in Ω. When the arc energy is calculated in real time Reaching the preset arc energy safety limit At that time, the secondary forced arc extinction control is triggered.

9. The method for rapid suppression and isolation of arc flash faults in a power distribution cabinet according to claim 5, characterized in that, The energy dissipation calculation formula for the transfer current of the energy absorption unit is as follows: ， In the formula, The energy dissipated by the bypass branch current in the energy absorption unit is expressed in J. This is the moment when the current begins to shift to the bypass branch. The moment when the arc current drops below the sustaining current. The value of the current in the bypass branch at time t is the instantaneous value, in amperes (A). This is the equivalent dissipation resistance of the energy absorption unit, measured in Ω.

10. The method for rapid suppression and isolation of arc flash faults in a distribution cabinet according to claim 1, characterized in that, The criteria for determining whether the arc is in the precursor or early stage of formation in step S3 are as follows: ≥ ,in The arc risk assessment value output by the arc risk comprehensive discrimination model. This is the adaptively adjusted arc risk threshold.

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