A high-voltage electric cabinet of a power plant installed with a fire alarm device

Abstract

A high-voltage switchgear for power plants equipped with a fire alarm device includes a sealed cabinet door at the front and ventilation windows on both side walls. It also includes a fire alarm, a drive mechanism, a sealing device, and a fire extinguishing device. The fire alarm is mounted on the high-voltage switchgear and houses an alarm system. The drive mechanism includes a servo motor, a winding reel driven by the servo motor, and a sealing pull rope fixed to the winding reel. The servo motor is electrically connected to and controlled by the alarm system. The sealing device includes a sealing rod and multiple sealing plates. The sealing rod is rotatably mounted on the ventilation window of the high-voltage switchgear, and the multiple sealing plates are fixed to the sealing rod. The other end of the sealing pull rope is connected to one end of the sealing rod. The fire extinguishing device includes a fire extinguisher with its nozzle located inside the high-voltage switchgear. The winding of the sealing pull rope rotates the sealing plates to a vertically parallel sealed state and activates the fire extinguisher, enhancing the fire safety reliability of the high-voltage switchgear.

Description

Technical Field

[0001] This invention relates to a high-voltage electrical cabinet for power plants equipped with a fire alarm device, belonging to the technical field of high-voltage electrical cabinets. Background Technology

[0002] Existing high-voltage switchgear in power plants plays a crucial role in the power system. It typically employs a metal cabinet structure, housing electrical components such as high-voltage circuit breakers and disconnect switches, and is equipped with smoke and temperature alarms to promptly warn of fires or fires within the cabinet, ensuring the safe and stable transmission of power. However, this existing technology has significant drawbacks: even if the alarms are accurately triggered, personnel may be located in distant areas or preoccupied with other tasks, often unable to immediately reach the scene for firefighting. During this response interval, the fire can easily spread rapidly within the high-voltage switchgear, and the accumulated heat may cause electrical components to explode or deflagrate, posing a serious threat to the safe operation of the entire power plant. Summary of the Invention

[0003] To address the aforementioned problems in the existing technology, this invention provides a power plant high-voltage switchgear equipped with a fire alarm device, ensuring seamless connection from fire detection to fire suppression, and significantly enhancing the fire safety reliability of the high-voltage switchgear.

[0004] The technical solution of the present invention is as follows: A power plant high-voltage switchgear equipped with a fire alarm device includes a high-voltage switchgear with a sealed door at the front end and ventilation windows on both side walls. It also includes a fire alarm, a drive mechanism, a sealing device, and a fire extinguishing device. The fire alarm is mounted on the high-voltage switchgear and houses an alarm system. The drive mechanism includes a servo motor, a winding reel driven by the servo motor, and a sealing pull rope with one end wound and fixed to the winding reel. The servo motor is electrically connected to and controlled by the alarm system. The sealing device includes a sealing rod and multiple sealing plates. The sealing rod is rotatably mounted on the ventilation window of the high-voltage switchgear, and the multiple sealing plates are fixed to the sealing rod. The other end of the sealing pull rope is connected to one end of the sealing rod. The fire extinguishing device includes a fire extinguisher installed outside the high-voltage switchgear, with the fire nozzle located inside the high-voltage switchgear. The sealing pull rope rotates the sealing plates to a vertically parallel sealed state, and the fire extinguisher is activated.

[0005] The winding reel has two sealing ropes fixedly wound around it, and the two sealing ropes control the sealing devices located on the ventilation windows on both sides of the high-voltage cabinet. The pulley assembly includes two sets of symmetrical structures corresponding to the ventilation windows on both sides of the high-voltage cabinet. Each set includes a first pulley and a second pulley. The first pulley and the second pulley are rotatably installed inside the high-voltage cabinet via a rotating shaft. After the sealing rope is led out from the winding reel, it passes around the first pulley and the second pulley respectively and is connected to the end of the sealing rotating rod on the corresponding side. A torsion spring is installed on the rotating shaft of the first pulley and the second pulley. The tension of the torsion spring keeps the sealing rotating rod in its initial position, causing the sealing plate to open and allowing the ventilation window to pass through.

[0006] The device includes two fire extinguishers, each controlled by a sealed pull rope. A vertical groove is provided on the high-voltage cabinet, through which the fire extinguisher's handle passes and is located inside the cabinet. The extinguishing device also includes a fire extinguishing block with a through hole in its center, which is slidably fitted onto a limiting rod fixed inside the high-voltage cabinet. A V-shaped groove is provided at the end of the fire extinguishing block near the handle, tapering away from the handle. The end of the fire extinguishing block away from the handle is fixedly connected to the sealed pull rope. The fire extinguisher is activated by squeezing the handle through the V-shaped groove.

[0007] The fire extinguisher is fixed to the outside of the high-voltage cabinet by an installation structure. The installation structure includes a connecting ring. The connecting ring is fixedly installed on the outside of the high-voltage cabinet. The top of the connecting ring is used to support the fire extinguisher. A connecting seat is fixedly connected to the inner ring surface of the connecting ring. The connecting seat has an arc-shaped locking surface that matches the shape of the fire extinguisher bottle. The connecting seat can surround the upper part of the fire extinguisher bottle and lock it, thereby securing the fire extinguisher to a predetermined position together with the connecting ring.

[0008] The ventilation window is equipped with a detachable filter screen.

[0009] The alarm system includes a sensing module for detecting fire signals inside the high-voltage switchgear, a signal processing module connected to the sensing module, an alarm module connected to the signal processing module, and a control module connected to the signal processing module. The sensing module includes at least sensors for collecting smoke concentration signals, temperature signals, and flame signals. The signal processing module receives and processes the fire signals collected by the sensing module and is configured to run a multi-level fire analysis and decision-making program, which includes multiple processing levels based on different response speeds and judgment logic. The alarm module issues audible and visual alarms and a remote alarm when the signal processing module determines that a fire has occurred. The servo motor is controlled by the control module and drives the winding reel to rotate according to the decision result of the signal processing module.

[0010] The alarm system implements a hierarchical fusion decision method based on the characteristics of high-voltage electrical cabinet fires. This method is implemented by the signal processing module and specifically includes: establishing a primary rapid response layer, an intermediate feature confirmation layer, and a high-level linkage decision layer. The primary rapid response layer is configured to make over-limit judgments based on signals from a single sensor, and is used to issue early warnings for explosive fires. The intermediate feature confirmation layer is configured to perform temporal correlation and logical composite judgment based on sensor signals of at least two different physical principles, in order to distinguish between real fire and interference, and to determine the stage of fire development. The advanced linkage decision-making layer is configured to receive the outputs of the primary and intermediate layers, and, in conjunction with the real-time electrical parameters of the high-voltage switchgear, conduct a comprehensive risk assessment, and ultimately decide whether to initiate sealing and fire extinguishing actions, and determine the urgency level of the initiation.

[0011] The judgment logic of the primary fast response layer includes: Arc flash explosion early warning sub-logic: When the flame signal If a high-intensity pulse occurs within <100ms, and at the same time, the current waveform of the relevant circuit in the high-voltage cabinet is monitored to show high-frequency oscillation or sudden rise, the highest level of early warning will be triggered immediately, and the sealing device will be activated first. The judgment logic of the intermediate feature confirmation layer includes: Insulation overheating and smoldering judgment sub-logic: When the temperature signal The smoke concentration signal showed a stable upward trend within a preset time period, and the smoke concentration signal at the same time... Increment With temperature rise When the ratio remains within a specific range, it is judged as overheating and smoldering of the insulating material; Electrical arc development judgment sub-logic: When the electrical arc flash explosion warning is triggered for the first time, if the temperature signal... The rate of increase of the flame signal continuously exceeds an extremely high threshold, and the flame signal If the signal switches to a continuous high level, it is determined to be a stable electrical arcing fire.

[0012] The advanced collaborative decision-making layer is configured to run a dynamic risk integral algorithm to generate the final initiation decision, as follows: Step A: Assign basic risk scores to different types of events. : Trigger the arc flash explosion warning sub-logic. = 80 points; Intermediate layer insulation overheating and smoldering confirmed. = 60 points; The intermediate level confirmed the development of electrical arc combustion. = 90 points; Step B: Introduce the environmental gain coefficient Adjust the base score: If the high-voltage switchgear cabinet has recent records of frequent transient current surges, either through historical data learning or manual settings, then... Take 1.2; if the environment is humid and dusty, then Take 1.1; under normal circumstances =1.0; Calculate the corrected risk score = * ; Step C: Introduce persistent gain: If the same event persists without being eliminated, for each preset period, Add a fixed score; Step D: Comprehensive Judgment: When When the first threshold is exceeded, the control module activates the drive mechanism to close the sealing plate; when If the second threshold is exceeded, the fire extinguisher is immediately triggered while the sealing plate is closed.

[0013] The present invention has the following beneficial effects: This invention uses a servo motor to drive a winding reel to wind up the sealing rope, which in turn pulls the sealing rod to rotate and causes multiple sealing plates to be arranged vertically and parallel, thus achieving rapid sealing of the ventilation window of the high-voltage cabinet. This effectively blocks airflow and prevents the fire from spreading due to oxygen-assisted combustion. Meanwhile, the invention achieves automatic triggering of the fire extinguisher by pulling the fire block along the limiting rod during the sealing rope winding process, and using its V-shaped groove to squeeze the fire extinguisher's fire handle, thus achieving the effect of timely spraying of dry powder extinguishing agent and suppressing the fire inside the cabinet. This invention achieves early warning of electric arc flash explosions, accurate identification of fire types, and graded emergency response based on quantitative risk assessment through the coordinated operation of a hierarchical fusion decision method and a dynamic risk integral algorithm. This achieves the effect of optimizing response strategies and minimizing losses caused by misoperation or over-handling while ensuring safety. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the back of the high-voltage switchgear of the present invention; Figure 3 This is a schematic diagram of the installation of the fire extinguishing device of the present invention; Figure 4 This is a partial cross-sectional view of the high-voltage switchgear of the present invention; Figure 5 This is a schematic diagram of the drive mechanism structure of the present invention; Figure 6 For the present invention Figure 5 Enlarged view of part A in the middle; Figure 7 This is a schematic diagram of the sealing pull rope driven fire-fighting block of the present invention; Figure 8 For the present invention Figure 7 Enlarged view of part B in the middle; Figure 9 This is a block diagram of the alarm system of the present invention.

[0015] The reference numerals in the figure are as follows: 1. High-voltage switchgear; 2. Sealed cabinet door; 3. Servo motor; 4. Filter screen; 5. Sealing plate; 6. Fire alarm; 7. Fire extinguisher; 8. Fire nozzle; 9. Fire handle; 10. Connecting ring; 11. Connecting seat; 12. Sealing rotating rod; 13. Sealing pull rope; 14. Reel; 15. First pulley; 16. Second pulley; 17. Fire block; 18. Limit rod; 19. Sensing module; 20. Signal processing module; 21. Alarm module; 22. Control module. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0017] Please see Figures 1 to 4 The invention provides a technical solution: This embodiment of a power plant high-voltage switchgear equipped with a fire alarm device includes a high-voltage switchgear 1. The front of the high-voltage switchgear 1 has a sealed door 2 that opens and closes. Ventilation windows are provided on both side walls of the high-voltage switchgear 1. It also includes a fire alarm 6, a drive mechanism, a sealing device, and a fire extinguishing device. The fire alarm 6 is mounted on the high-voltage switchgear 1 and contains an alarm system. The drive mechanism includes a servo motor 3, a winding reel 14 driven by the servo motor 3, and a sealing pull rope 13 with one end wound and fixed to the winding reel 14. The servo motor 3 is electrically connected to the alarm system. The sealing device includes a sealing rotating rod 12 and multiple sealing plates 5. The sealing rotating rod 12 is rotatably mounted on the ventilation window of the high-voltage cabinet 1, and the multiple sealing plates 5 are all fixed on the sealing rotating rod 12. The other end of the sealing pull rope 13 is connected to one end of the sealing rotating rod 12. The fire extinguishing device includes a fire extinguisher 7 installed outside the high-voltage cabinet 1. The fire nozzle 8 of the fire extinguisher 7 is located inside the high-voltage cabinet 1. The sealing plates 5 are rotated to a vertically parallel sealed state by the winding of the sealing pull rope 13, and the fire extinguisher 7 is activated.

[0018] Two sealing pull ropes 13 are wound and fixed on the winding reel 14. The two sealing pull ropes 13 control the sealing devices located on the ventilation windows on both sides of the high voltage cabinet 1. The pulley assembly includes two sets of symmetrical structures corresponding to the ventilation windows on both sides of the high voltage cabinet 1. Each set includes a first pulley 15 and a second pulley 16. The first pulley 15 and the second pulley 16 are rotatably installed inside the high voltage cabinet 1 via a rotating shaft. After the sealing pull ropes 13 are led out from the winding reel 14, they pass around the first pulley 15 and the second pulley 16 respectively and are connected to the end of the sealing rotating rod 12 on the corresponding side. Torsion springs are installed on the rotating shafts of the first pulley 15 and the second pulley 16. The tension of the torsion springs keeps the sealing rotating rod 12 in the initial position, causing the sealing plate 5 to open so that the ventilation window is unobstructed.

[0019] Specifically, when a fire occurs inside the high-voltage cabinet 1 due to electrical faults or other reasons, the initial smoke, high temperature or open flame is detected by the fire alarm 6 installed inside the cabinet. The alarm system analyzes and processes the received signals. When the signal value exceeds a preset threshold or conforms to a specific fire alarm algorithm, it determines that a fire has occurred. Simultaneously, it issues a command to immediately activate the audible and visual alarms and initiate remote alarm functionality; the alarm system then sends a start signal to the drive mechanism.

[0020] The command triggers the servo motor 3 to start. The output shaft of the servo motor 3 begins to rotate, driving the winding reel 14 connected to it to rotate synchronously. The two sealing pull ropes 13 fixed on the winding reel 14 are then wound up. On the path between the winding reel 14 and the sealing rotating rod 12, the sealing pull ropes 13 pass over the first pulley 15 and the second pulley 16. The pulley group changes the transmission direction of the sealing pull ropes 13 and applies the rotational motion of the winding reel 14 to the sealing rotating rod 12, causing the sealing rotating rod 12 to rotate synchronously, thereby closing the sealing plate 5 and forming a sealed state for the high-voltage cabinet 1. In the non-alarm state, the torque of the torsion springs installed on the shafts of the first pulley 15 and the second pulley 16 keeps the sealing rotating rod 12 in its initial position through the pull ropes, thereby opening the sealing plate 5 and ensuring the ventilation function of the vent window and the filter screen 4.

[0021] Specifically, the tension generated by the winding of the sealing rope 13 overcomes the resistance of the torsion spring, pulling the sealing rod 12 to rotate around its axis. Since multiple sealing plates 5 are fixed to the sealing rod 12, they rotate synchronously, changing from an initial open state to a vertically aligned and parallel state, thus tightly sealing the ventilation windows on both sides of the high-voltage cabinet 1. This action quickly cuts off the oxygen supply to the flames inside the cabinet, achieving the first step of suffocation fire suppression.

[0022] There are two fire extinguishers 7, and each fire extinguisher 7 is controlled by two sealed pull ropes 13. The high-voltage cabinet 1 is provided with a vertical groove, and the fire handle 9 of the fire extinguisher 7 passes through the vertical groove and is located inside the high-voltage cabinet 1. The fire extinguishing device also includes a fire block 17. A through hole is opened in the middle of the fire block 17, and the through hole is slidably fitted onto a limiting rod 18 fixed inside the high-voltage cabinet 1. A V-shaped groove is provided at the end of the fire block 17 near the fire handle 9. The V-shaped groove is tapered away from the fire handle 9. The end of the fire block 17 away from the fire handle 9 is fixedly connected to the sealed pull rope 13. The fire extinguisher 7 is activated by squeezing the fire handle 9 through the V-shaped groove.

[0023] During the same process of the sealing pull rope 13 being wound up and performing the sealing action described above, the fire extinguisher block 17 connected to a specific point on the sealing pull rope 13 is pulled. The fire extinguisher block 17 slides along the limiting rod 18, and its end near the fire extinguisher 7, i.e., the end with the V-shaped groove, squeezes the fire extinguisher handle 9 of the fire extinguisher 7. This squeezing action is equivalent to manually pressing the fire extinguisher handle 9, thereby triggering the fire extinguisher 7.

[0024] As a preferred embodiment, the limiting rod 18 is provided with a guide groove, and the fire-fighting block 17 is slidably engaged in the guide groove via a pin; the guide groove includes a first stroke section, a locking section and a second stroke section connected in sequence; The first stroke segment corresponds to the entire process in which the sealing pull rope 13 pulls the sealing rotating rod 12 to rotate and causes all the sealing plates 5 to rotate from the open state to the closed sealing state; during this process, the pin slides within the first stroke segment, a gap is maintained between the V-shaped groove of the fire block 17 and the fire handle 9, and the fire extinguisher 7 is not triggered; The locking section is a groove or protrusion with a specific profile, which is configured to overcome an additional resistance or change the direction of movement when the pin moves to this point. This process corresponds to the moment when the sealing plate 5 reaches the fully closed position and locks. The second stroke begins at the end of the locking section, corresponding to the continued rope pull stroke after the sealing action is completed; when the pin enters the second stroke, the fire block 17 begins to move substantially along the axial direction of the limiting rod 18, and the V-groove squeezes the fire handle 9, thereby triggering the fire extinguisher 7.

[0025] When triggered, the extinguishing agent stored inside the fire extinguisher 7 is propelled by pressure and sprayed at high speed into the high-voltage cabinet 1 through the fire nozzle 8, directly acting on the fire source to extinguish the open flame and cool down the area, achieving the second step of fire extinguishing. Throughout the process, the fire extinguisher 7 is securely fixed to the outside of the high-voltage cabinet 1 by the mounting structure consisting of the connecting ring 10 and the connecting seat 11, ensuring reliable operation.

[0026] After the fire is extinguished, the system can be manually or remotely reset. Servo motor 3 reverses, releasing the sealing pull rope 13. Under the reset torque of the torsion spring, the sealing rod 12 drives the sealing plate 5 to rotate back to the open position, and the fire-fighting block 17 also resets as the pull rope loosens. The device returns to its initial monitoring state, awaiting the next fire alarm signal.

[0027] It is worth mentioning that the high-voltage cabinet 1 is equipped with a vertical groove, and a sealing through-wall component is installed at the corresponding movement path of the fire handle 9. The sealing through-wall component is a flexible corrugated pipe. This corrugated pipe is made of a high-temperature resistant, flame-retardant, and highly elastic material (such as silicone rubber or Teflon-coated fiberglass cloth). Fixed flanges are provided at both ends of the corrugated pipe, which are bolted to the inner and outer sides of the wall panel of the high-voltage cabinet 1 to achieve a static seal. The movable end of the fire handle 9 extends into the interior of the high-voltage cabinet 1 through the inner cavity of the corrugated pipe 24.

[0028] When a fire occurs, the sealing pull rope 13 retracts and pulls the fire block 17, which in turn compresses the fire handle 9. During this compression, the fire handle 9 pushes the bellows 24, causing it to deform. Throughout the compression stroke, the corrugated structure of the bellows 24 remains in close contact with the handle 9 or forms a sealed telescopic channel within it, maintaining a reliable seal and effectively preventing external air from entering the cabinet through this gap.

[0029] Fire extinguisher 7 is fixed to the outside of high-voltage cabinet 1 by an installation structure; the installation structure includes a connecting ring 10; the connecting ring 10 is fixedly installed on the outside of high-voltage cabinet 1, the top of the connecting ring 10 is used to support the fire extinguisher 7, and a connecting seat 11 is fixedly connected to the inner ring surface of the connecting ring 10. The connecting seat 11 has an arc-shaped locking surface that matches the shape of the fire extinguisher 7. The connecting seat 11 can surround the upper part of the fire extinguisher 7 and lock it, thereby securing the fire extinguisher 7 to the predetermined position together with the connecting ring 10.

[0030] A filter screen 4 is removably installed on the ventilation window.

[0031] Example 1: The alarm system includes a sensing module 19 for detecting fire signals inside the high-voltage switchgear 1, a signal processing module 20 connected to the sensing module 19, an alarm module 21 connected to the signal processing module 20, and a control module 22 connected to the signal processing module 20. The sensing module 19 includes at least sensors for collecting smoke concentration signals, temperature signals, and flame signals. The signal processing module 20 receives and processes the fire signals collected by the sensing module 19 and is configured to run a multi-level fire analysis and decision program, which includes multiple processing levels based on different response speeds and judgment logic. The alarm module 21 issues audible and visual alarms and a remote alarm when the signal processing module 20 determines that a fire has occurred. The servo motor 3 is controlled by the control module 22 and drives the winding reel 14 to rotate according to the decision result of the signal processing module 20.

[0032] The alarm system implements a hierarchical fusion decision method based on the characteristics of high-voltage electrical cabinet fires. This method is implemented by the signal processing module 20 and specifically includes: establishing a primary rapid response layer, an intermediate feature confirmation layer, and a high-level linkage decision layer. The primary rapid response layer is configured to make over-limit judgments based on signals from a single sensor, and is used to issue early warnings of explosive fires. The goal of the primary fast response layer is to react immediately to extremely short-lived but highly dangerous arc flashes using the fastest detection methods. In this system, this function is implemented by a flame sensor, which responds quickly to the intense light of an arc, much faster than temperature rise or smoke accumulation. This layer is configured to continuously monitor the raw voltage signal from the flame sensor. When the signal amplitude exceeds a dynamic threshold determined by background noise within a short period of time, and the high-pulse state lasts for less than 100 milliseconds, it is identified as a suspected arc flash event. This layer immediately outputs an arc flash warning signal to the higher-level layer without waiting for confirmation from other sensors.

[0033] Specifically, the system continuously monitors the output of the flame sensor under normal fire-free conditions and takes the average of its effective voltage value over a recent period (e.g., 60 seconds). This value represents the ambient light and circuitry background noise level; The term "high intensity" refers to the amplitude of the flame signal voltage. It rises sharply within a very short time and exceeds the dynamic threshold determined by the background noise. Specifically, when the following conditions are met... When this occurs, the signal is considered to have reached a high-intensity threshold. The scaling factor is... These are core parameters.

[0034] coefficient The settings must be able to effectively distinguish the strong light signal of an electric arc flash from the weak electrical sparks or occasional ambient light interference that may occur during normal switch operations. Analysis of measured optical data from overvoltage arcs and fault arcs in typical high-voltage switchgear shows that the peak light intensity pulse can typically reach more than 10 times the background noise. To ensure reliable detection and allow for margin, the proportionality coefficient... It should be selected between 5 and 15. A preferred example value is K = 8. That is, when When the signal intensity meets the high-intensity condition, it is determined that the signal intensity meets the high-intensity condition.

[0035] While meeting the above intensity requirements, the duration of the high-amplitude signal must be less than 100ms to conform to the instantaneous characteristics of electric arc flash explosion and exclude continuously burning flames.

[0036] The intermediate feature confirmation layer is configured to perform temporal correlation and logical composite judgment based on sensor signals of at least two different physical principles, in order to distinguish between real fire and interference, and to determine the stage of fire development. The goal of the intermediate feature confirmation layer is to improve the accuracy of judgments, distinguish between real fires and false alarms from single sensors (such as dust obstruction, electrical sparks, or proximity of heat sources), and identify the physical type of the fire (open flame or smoldering). To achieve this goal, this layer is configured to simultaneously analyze time-series data from at least two independent sensors based on different principles. Specifically, it primarily handles the following two types of composite judgments: Insulation overheating and smoldering detection: Data from temperature and smoke sensors are analyzed simultaneously. The system calculates the slope of the temperature rise over a continuous time window (e.g., 10 minutes) and simultaneously calculates the increase in smoke concentration during that time period. By determining whether the ratio of the increase in smoke concentration to the temperature rise remains within a typical range, the correlation between smoke generated by the overheating decomposition of insulation materials and the temperature rise is identified, thus distinguishing it from simple temperature fluctuations or airborne dust.

[0037] Stable Arc Fire Assessment: Upon receiving an arc flash warning from the primary layer, this layer initiates a short confirmation window. During this period, two conditions must be met simultaneously: the flame sensor signal must remain above a threshold (indicating a persistent open flame), and the temperature sensor's measured rate of temperature rise must exceed a threshold reflecting intense combustion (e.g., 20°C / second). Only when both conditions are met is it confirmed as a stable arc fire. This layer filters out interference such as isolated transient arcs (e.g., operational overvoltage sparks) by correlating multiple signal thresholds with time.

[0038] The advanced linkage decision-making layer is configured to receive the outputs of the primary and intermediate layers, and, in conjunction with the real-time electrical parameters of the high-voltage switchgear, conduct a comprehensive risk assessment, and ultimately decide whether to initiate sealing and fire extinguishing actions, and determine the urgency level of the initiation.

[0039] It receives early warning signals from the primary layer and fire type and confidence level confirmation from the intermediate layer. Based on this, this layer incorporates real-time electrical parameters from the power distribution monitoring system (such as current surge data provided by a fault recorder) as auxiliary decision-making data. This layer runs a dynamic risk assessment algorithm: assigning and accumulating risk scores for events of different types and confidence levels; simultaneously, weighting the risk scores according to electrical parameters (such as whether there is a continuous short-circuit current) and environmental parameters (such as humidity inside the cabinet). The algorithm sets two action thresholds: when the risk score exceeds the lower first threshold, it is determined that isolation measures are required, and the decision is to activate the sealing device; when the risk score exceeds the higher second threshold due to the fire continuing or intensifying, it is determined that immediate extinguishing is required, and the decision is to activate the fire extinguishing device while sealing.

[0040] The judgment logic of the primary fast response layer includes: Arc flash explosion early warning sub-logic: When the flame signal If a high-intensity pulse occurs within <100ms, and at the same time the current waveform of the relevant circuit in the high-voltage cabinet 1 is monitored to show high-frequency oscillation or sudden rise, the highest level of early warning will be triggered immediately, and the sealing device will be activated first. The judgment logic of the intermediate feature confirmation layer includes: Insulation overheating and smoldering judgment sub-logic: When the temperature signal The smoke concentration signal showed a stable upward trend within a preset time period, and the smoke concentration signal at the same time... Increment With temperature rise When the ratio remains within a specific range, it is judged as overheating and smoldering of the insulating material; The specific range can be determined as follows: Select a sample of the main insulating material actually used in this high-voltage switchgear 1, and slowly heat it from room temperature to its thermal decomposition temperature in an experimental device simulating the switchgear environment. Record the corresponding data of smoke concentration and temperature throughout the process. By analyzing the data curves, determine the characteristic range of the smoke-temperature rise ratio during its typical smoldering stage. The setting of the specific range is based on the estimation of known physical properties such as the pyrolysis smoke production coefficient and specific heat capacity of the target insulating material, and is comprehensively calibrated by combining the post-hoc analysis of relevant data from historical failure cases. For example, by analyzing overheat test data of common cable insulation materials (such as PVC and XLPE), the specific range can be set as 0.8 ≤ ( ≤ 2.5. Those skilled in the art can make adaptive adjustments based on this, depending on the specific materials and environment inside the cabinet.

[0041] Electrical arc development judgment sub-logic: When the electrical arc flash explosion warning is triggered for the first time, if the temperature signal... The rate of increase of the flame signal continuously exceeds an extremely high threshold, and the flame signal If the signal switches to a continuous high level, it is determined to be a stable electrical arcing fire.

[0042] The extremely high threshold is based on the description of the temperature rise characteristics of arc faults in electrical safety standards, and ensures that the threshold is much higher than the maximum temperature rise rate that may occur during normal operation or short-term overload of the equipment to prevent misjudgment. A standard arc generation experiment can be conducted in a simulation cabinet to record the temperature change curve of the stable combustion stage of the arc and calculate the average temperature rise rate of its initial stage, which can be used as the benchmark for setting the extremely high threshold. Those skilled in the art can adjust it according to the actual voltage level, cabinet volume and protection requirements.

[0043] The advanced collaborative decision-making layer is configured to run a dynamic risk integral algorithm to generate the final initiation decision, as follows: Step A: Assign basic risk scores to different types of events. : Trigger the arc flash explosion warning sub-logic. = 80 points; Intermediate layer insulation overheating and smoldering confirmed. = 60 points; The intermediate level confirmed the development of electrical arc combustion. = 90 points; Step B: Introduce the environmental gain coefficient Adjust the base score: If, through historical data learning or manual settings, the high-voltage switchgear 1 cabinet has recently recorded frequent instantaneous current surges, then... Take 1.2; if the environment is humid and dusty, then Take 1.1; under normal circumstances =1.0; Calculate the corrected risk score = * ; Step C: Introduce persistent gain: If the same event persists without being eliminated, for each preset period, Add a fixed score; Step D: Comprehensive Judgment: When When the first threshold is exceeded, the control module 22 activates the drive mechanism and closes the sealing plate 5; when When the threshold is exceeded, the fire extinguisher 7 is immediately triggered while the sealing plate (5) is closed.

[0044] The first and second thresholds can be determined collaboratively as follows: First, in a laboratory simulation environment, collect a large amount of data on initial fire cases that can be extinguished by suffocation with just sealing; the upper limit of the statistical risk score for these cases can serve as a reference benchmark for setting the first threshold. Second, collect initial data on fire cases that have developed into open flames and require the activation of fire extinguishers; the lower limit of the statistical risk score for these cases can serve as a reference benchmark for setting the second threshold. The second threshold should be ensured to be higher than the first threshold by a reasonable margin to prevent response oscillations. As an example, for a standard 10kV switchgear, the first threshold can be set to 70 points and the second threshold to 85 points.

[0045] Level 1 response ( >First Threshold): The fire risk has reached a level requiring physical intervention, but it's uncertain whether immediate extinguishing agent application is necessary. At this point, a sealing process is initiated to attempt to control the initial fire through "smothering." This step is low-cost, pollution-free, and buys time for personnel to respond.

[0046] Level II response ( >Second Threshold): If the fire is developing rapidly or open flames have been confirmed, and the risk is extremely high, suffocation may no longer be sufficient. In this case, while maintaining a sealed environment, immediately activate the fire extinguishing system for powerful suppression.

[0047] Threshold-to-threshold state: When the risk score is between two thresholds, the system is in a sealed-off, suffocating state, while continuous monitoring continues. If the seal is effective, the fire is suppressed and the score decreases; if ineffective, the fire develops and the score continues to accumulate until a level-two response is triggered.

[0048] Example 2: The alarm system includes a sensing module 19 for detecting fire signals inside the high-voltage switchgear 1, a signal processing module 20 connected to the sensing module 19, an alarm module 21 connected to the signal processing module 20, and a control module 22 connected to the signal processing module 20. The signal processing module 20 is used to receive and process fire signals. The alarm module 21 is used to issue audible and visual alarms and remote alarms when a fire is detected. The servo motor 3 is controlled by the control module 22 and drives the winding reel 14 to rotate. The fire signals include smoke concentration signals, temperature signals, and flame signals. The signal processing module 20 performs information fusion based on at least two of the smoke concentration signals, temperature signals, and flame signals according to a preset logical decision rule to determine whether a fire has occurred. The logical decision rule includes comparing the received signals with a preset alarm threshold.

[0049] The signal processing module 20 has preset smoke concentration alarm thresholds and temperature alarm thresholds, and monitors whether a flame signal is detected. The logical decision rules include any one or a combination of the following decision logics in this embodiment: Decision logic 1: When the smoke concentration signal value exceeds the smoke concentration alarm threshold and the temperature signal value exceeds the temperature alarm threshold, it is determined that a fire has occurred; Decision logic 2: When a flame signal is detected and the temperature signal value rises at a rate exceeding a preset temperature rise rate threshold within a preset time, it is determined that a fire has occurred; Decision logic 3: A weighted fusion algorithm is used to assign weight coefficients to the smoke concentration signal, temperature signal, and flame signal respectively, calculate a comprehensive fire risk value, and when the comprehensive fire risk value exceeds a preset risk threshold, it is determined that a fire has occurred.

[0050] In the third judgment logic, the comprehensive fire risk value is calculated according to the following steps: S1: Obtain the smoke concentration measurement value at the current moment. Temperature measurement value and flame status signals ,in This is a binary signal; it takes a value of 1 when a flame is detected and a value of 0 when no flame is detected. S2: Normalize the measured values ​​to obtain normalized smoke concentration values. Normalized temperature value ,in , , The smoke concentration alarm threshold is... The temperature alarm threshold is defined as follows; S3: According to the formula Calculate the comprehensive fire risk value, where , , The preset weighting coefficients are used, and they satisfy the following conditions: ; S4: Calculate the comprehensive fire risk value With preset risk threshold If a comparison is made, If so, it is determined that a fire has occurred.

[0051] The sensing module 19 is the signal acquisition front end of the system, responsible for sensing fire characteristic signals from multiple dimensions. In this embodiment, it preferably includes the following sensors: Photoelectric smoke sensor: Used to detect smoke particles generated inside the high-voltage cabinet 1 due to overheating of the insulating material or electric arc. Its working principle is to monitor the change in the intensity of scattered light caused by smoke particles in the dark cavity illuminated by the laser beam or LED light, and convert this change into an analog voltage signal or digital signal (i.e., the smoke concentration signal) of smoke concentration for output.

[0052] Thermistor temperature sensor: Used to directly monitor the air temperature inside the high-voltage cabinet 1. This sensor is preferably an NTC (negative temperature coefficient) thermistor, whose resistance decreases as temperature increases. The resistance change is converted into a temperature-voltage signal (i.e., the temperature signal) by a matching measurement circuit. This sensor should be placed near easily heated electrical components inside the cabinet (such as circuit breaker contacts and cable joints).

[0053] Infrared flame sensor: Used to detect the unique infrared radiation of open flames. When an arc short circuit occurs inside the high-voltage cabinet 1 or when materials ignite, this sensor can respond quickly and output a switching signal (i.e., the flame status signal). For example, when a flame is detected, a high level (logic "1") is output, and when no flame is detected, a low level (logic "0") is output.

[0054] The signal processing module 20 is the core of the system and is usually implemented by a microcontroller unit, which has a fire detection algorithm program embedded inside.

[0055] The microcontroller's analog-to-digital converter pin receives analog voltage signals from the smoke and temperature sensors and converts them into a digital quantity, namely the smoke concentration measurement value. and temperature measurement value For the switch signal output by the flame sensor, its status is read directly through the digital I / O port. .

[0056] The pre-defined logic decision rules in the microcontroller are designed to reduce false alarms and improve reliability. Specifically, they can be implemented through a combination of one or more of the following decision logics: Judgment Logic 1: This logic focuses on detecting slowly developing fires with smoldering characteristics. The microcontroller's program has pre-stored smoke concentration alarm thresholds. and temperature alarm threshold These thresholds were determined by referencing relevant standards and combining them with tests on the internal environment characteristics of high-voltage switchgear 1. A fire is determined when both of the following conditions are met simultaneously: Condition 1: ; Condition 2: .

[0057] Judgment Logic 2: This logic is designed for rapidly developing fires that may instantly produce open flames. The program includes preset temperature thresholds. In addition, a temperature rise rate threshold is preset. The execution steps of this logic are as follows: The microcontroller continuously monitors the temperature value and calculates the temperature change over a preset time period to obtain the temperature rise rate.

[0058] When the flame sensor outputs a signal When the temperature changes from 0 to 1 (indicating the detection of an open flame) and the calculated rate of temperature rise exceeds the preset ΔT / Δt threshold, it is determined to be a fire.

[0059] This logic combines the immediacy of flames with the rapid changes in temperature, enabling extremely early warning of deflagration fires.

[0060] Judgment Logic 3: Step S1: Signal Acquisition. As described above, acquire... , ,

[0061] Step S2: Normalization. To avoid problems caused by directly adding signals with different dimensions, normalization is performed. and Normalize: Normalized smoke concentration value: ; Normalized temperature value:

[0062] After this treatment, and It becomes a dimensionless ratio, and when its value is greater than 1, it indicates that the single-item threshold has been exceeded.

[0063] Step S3: Calculate the comprehensive fire risk value according to the formula. calculate; Weighting coefficient , , It is a preset value and satisfies The allocation of coefficients can reflect the emphasis on different fire characteristics. For example, in environments with high dust levels, the weighting of smoke can be appropriately increased. In locations prone to electric arcing, the flame can be enlarged. and temperature The weight.

[0064] Upon receiving a fire confirmation signal, the alarm module 21 activates the audible and visual alarm (such as a buzzer and a red warning light) installed on the high-voltage cabinet 1. Simultaneously, it sends alarm information, including the high-voltage cabinet number, location, and fire alarm level, to the remote monitoring center or the designated person's mobile phone through its built-in communication unit (such as a 4G / 5G module or an Ethernet interface).

[0065] The control module 22 can be integrated with the signal processing module 20 into the same microcontroller. After receiving the fire judgment result from the signal processing module 20, it immediately controls the power supply to the drive circuit of the servo motor 3, thereby initiating the entire sealing and fire extinguishing process.

[0066] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A power plant high-voltage switchgear equipped with a fire alarm device, comprising a high-voltage switchgear (1), wherein a sealed cabinet door (2) is provided at the front end of the high-voltage switchgear (1), and ventilation windows are provided on both side walls of the high-voltage switchgear (1), characterized in that: It also includes a fire alarm (6), a drive mechanism, a sealing device, and a fire extinguishing device; the fire alarm (6) is installed on the high-voltage cabinet (1), and an alarm system is installed inside it; the drive mechanism includes a servo motor (3), a winding reel (14) driven by the servo motor (3), and a sealing pull rope (13) with one end wound and fixed on the winding reel (14); the servo motor (3) is electrically connected to and controlled by the alarm system; the sealing device includes a sealing rotating rod (12) and multiple sealing plates (5); the sealing rotating rod... (12) Rotatably mounted on the ventilation window of the high-voltage cabinet (1), multiple sealing plates (5) are fixed on the sealing rotating rod (12), and the other end of the sealing pull rope (13) is connected to one end of the sealing rotating rod (12); the fire extinguishing device includes a fire extinguisher (7) installed outside the high-voltage cabinet (1), the fire nozzle (8) of the fire extinguisher (7) is located inside the high-voltage cabinet (1), and the sealing plate (5) is rotated to a vertically parallel sealed state by the winding of the sealing pull rope (13) and the fire extinguisher (7) is activated.

2. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 1, characterized in that: Two sealing pull ropes (13) are wound and fixed on the winding reel (14). The two sealing pull ropes (13) control the sealing devices located on the ventilation windows on both sides of the high voltage cabinet (1). The pulley assembly includes two sets of symmetrical structures corresponding to the ventilation windows on both sides of the high voltage cabinet (1). Each set includes a first pulley (15) and a second pulley (16). The first pulley (15) and the second pulley (16) are rotatably installed inside the high voltage cabinet (1) through a rotating shaft. After the sealing pull rope (13) is led out from the winding reel (14), it passes around the first pulley (15) and the second pulley (16) respectively, and is connected to the end of the sealing rotating rod (12) on the corresponding side. A torsion spring is installed on the rotating shaft of the first pulley (15) and the second pulley (16). The tension of the torsion spring keeps the sealing rotating rod (12) in the initial position, so that the sealing plate (5) opens to allow the ventilation window to pass through.

3. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 2, characterized in that: Two fire extinguishers (7) are provided, and the two fire extinguishers (7) are controlled by two sealing pull ropes (13) respectively. The high-voltage cabinet (1) is provided with a vertical groove. The fire handle (9) of the fire extinguisher (7) passes through the vertical groove and is located inside the high-voltage cabinet (1). The fire extinguishing device also includes a fire block (17). A through hole is opened in the middle of the fire block (17). The through hole is slidably fitted on a limiting rod (18) fixed inside the high-voltage cabinet (1). A V-shaped groove is provided at the end of the fire block (17) near the fire handle (9). The V-shaped groove is tapered away from the fire handle (9). The end of the fire block (17) away from the fire handle (9) is fixedly connected to the sealing pull rope (13). The fire extinguisher (7) is activated by squeezing the fire handle (9).

4. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 3, characterized in that: The fire extinguisher (7) is fixed to the outside of the high-voltage cabinet (1) by an installation structure; the installation structure includes a connecting ring (10); the connecting ring (10) is fixedly installed on the outside of the high-voltage cabinet (1), the top of the connecting ring (10) is used to support the fire extinguisher (7), and a connecting seat (11) is fixedly connected to the inner ring surface of the connecting ring (10). The connecting seat (11) has an arc-shaped locking surface that matches the shape of the fire extinguisher (7) bottle. The connecting seat (11) can surround the upper part of the fire extinguisher (7) bottle and lock it, so as to secure the fire extinguisher (7) to the predetermined position together with the connecting ring (10).

5. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 1, characterized in that: A filter screen (4) is detachably installed on the ventilation window.

6. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 1, characterized in that: The alarm system includes a sensing module (19) for detecting fire signals inside the high-voltage cabinet (1), a signal processing module (20) connected to the sensing module (19), an alarm module (21) connected to the signal processing module (20), and a control module (22) connected to the signal processing module (20). The sensing module (19) includes at least sensors for collecting smoke concentration signals, temperature signals, and flame signals. The signal processing module (20) is used to receive and process the fire signals collected by the sensing module (19), and is configured to run a multi-level fire analysis and decision program, which includes multiple processing levels based on different response speeds and judgment logic. The alarm module (21) is used to issue audible and visual alarms and remote alarms when the signal processing module (20) determines that a fire has occurred. The servo motor (3) is controlled by the control module (22) and drives the winding reel (14) to rotate according to the judgment result of the signal processing module (20).

7. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 6, characterized in that, The alarm system implements a hierarchical fusion decision method based on the characteristics of high-voltage electrical cabinet fires. This method is implemented by the signal processing module (20) and specifically includes: establishing a primary rapid response layer, an intermediate feature confirmation layer and a high-level linkage decision layer; the primary rapid response layer is configured to make over-limit judgments based on signals from a single sensor and is used to issue early warnings for explosive fires. The intermediate feature confirmation layer is configured to perform temporal correlation and logical composite judgment based on sensor signals of at least two different physical principles, in order to distinguish between real fire and interference, and to determine the stage of fire development. The advanced linkage decision-making layer is configured to receive the outputs of the primary and intermediate layers, and, in conjunction with the real-time electrical parameters of the high-voltage switchgear, conduct a comprehensive risk assessment, and ultimately decide whether to initiate sealing and fire extinguishing actions, and determine the urgency level of the initiation.

8. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 7, characterized in that, The judgment logic of the primary fast response layer includes: Arc flash explosion early warning sub-logic: When the flame signal If a high-intensity pulse occurs within <100ms, and at the same time the current waveform of the relevant circuit in the high-voltage cabinet (1) is monitored to have high-frequency oscillation or sudden rise, the highest level warning will be triggered immediately, and the sealing device will be activated first. The judgment logic of the intermediate feature confirmation layer includes: Insulation overheating and smoldering judgment sub-logic: When the temperature signal The smoke concentration signal showed a stable upward trend within a preset time period, and the smoke concentration signal at the same time... Increment With temperature rise When the ratio remains within a specific range, it is judged as overheating and smoldering of the insulating material; Electrical arc development judgment sub-logic: When the electrical arc flash explosion warning is triggered for the first time, if the temperature signal... The rate of increase of the flame signal continuously exceeds an extremely high threshold, and the flame signal If the signal switches to a continuous high level, it is determined to be a stable electrical arcing fire.

9. A power plant high-voltage switchgear equipped with a fire alarm device as described in claim 8, characterized in that, The advanced collaborative decision-making layer is configured to run a dynamic risk integral algorithm to generate the final initiation decision, as follows: Step A: Assign basic risk scores to different types of events. : Trigger the arc flash explosion warning sub-logic. = 80 points; Intermediate layer insulation overheating and smoldering were confirmed. = 60 points; The intermediate level confirmed the development of electrical arc combustion. = 90 points; Step B: Introduce the environmental gain coefficient Adjust the base score: If the high-voltage switchgear (1) has a history of frequent instantaneous current surges, either through historical data learning or manual settings, then... Take 1.2; if the environment is humid and dusty, then Take 1.1; under normal circumstances =1.0; Calculate the corrected risk score = * ; Step C: Introduce persistent gain: If the same event persists without being eliminated, for each preset period, Add a fixed score; Step D: Comprehensive Judgment: When When the first threshold is exceeded, the control module (22) activates the drive mechanism and closes the sealing plate (5); when When the second threshold is exceeded, the fire extinguisher (7) is immediately triggered while the sealing plate (5) is closed.

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