Electrolyzer cable targeted monitoring and multiple redundant interlock protection system

Abstract

This invention discloses a targeted monitoring and multi-redundant interlocking protection system for electrolytic cell cables. It achieves this by deploying detection points in targeted zones, forming a differentiated, encrypted, distributed deployment; employing a zone isolation and dual-network redundant transmission architecture, with physically independent and route-separated dual networks, enabling automatic and seamless switching in case of single-link failure; the control module incorporates temperature and humidity threshold correction, continuous delay filtering, single-point early warning without shutdown, and multi-point over-limit detection within the same zone (neighbor zone cross-cooperative judgment algorithm), eliminating instantaneous environmental interference; the execution layer is configured with dual-redundant shutdown via communication interlocking and an independent passive hard-wired safety circuit, ensuring reliable power-off even when disconnected from the network and PLC main program; the self-diagnosis and fault management unit simultaneously possesses functions for sensor unit disconnection, fault self-diagnosis, priority power-off of hierarchical branches, fault source tracing and storage, remote push, and authorized reset. This achieves precise allocation of monitoring resources to high-risk areas, completely resolving the problem of erroneous shutdowns and ensuring ultimate reliability of the protection function.

Description

Technical Field

[0001] This invention relates to the field of electrolytic cell safety monitoring technology, specifically to an electrolytic cell cable targeted monitoring and multi-redundant interlocking protection system. Background Technology

[0002] In electrolysis processes, electrolytic cells typically need to withstand high DC currents ranging from thousands to hundreds of thousands of amperes. During long-term operation, their power cables (including busbars, flexible connectors, and terminals) are highly susceptible to localized overheating due to factors such as increased contact resistance, insulation aging, overload, or environmental corrosion. When the heat accumulates to a critical point, it may ignite the cable insulation, leading to a fire, which in turn can cause a series of electrolytic cell shutdowns, equipment damage, and major safety accidents.

[0003] Currently, traditional protection methods mostly rely on temperature monitoring (such as infrared thermometry and thermocouples) or overcurrent protection. However, existing technologies have the following shortcomings: First, the monitoring deployment is rudimentary and lacks targeted coverage of vulnerable areas. Current technologies mostly employ a uniformly distributed monitoring approach, installing sensors at equal intervals within cable trays or trenches. This fails to address inherently vulnerable areas such as cable inlet contacts, terminal blocks, stress zones at cable tray corners, corrosion zones in cable trenches, and high-current outgoing connectors with differentiated, high-density deployments. These vulnerable areas are precisely where increased contact resistance, insulation aging, concentrated mechanical stress, and accelerated corrosion are most likely to occur. Uniformly distributed monitoring results in blind spots in high-risk areas, making it difficult to effectively detect early-stage hazards.

[0004] Secondly, single-point smoke sensors are easily affected by the workshop environment, leading to frequent false shutdowns. Electrolysis workshops generally have harsh environmental factors such as high humidity and high concentrations of dust. Single-point smoke sensors are prone to instantaneous interference signals due to water vapor condensation or dust settling. Existing solutions mostly use single-point threshold alarm logic, which triggers a shutdown once the single-point limit is exceeded, resulting in frequent false shutdowns and seriously affecting the continuous production of electrolytic cells.

[0005] Third, the protection system relies on a single communication network, and failure occurs when the link is broken. The shutdown command of the existing system depends entirely on the transmission of industrial communication networks. Once the communication link is interrupted, the controller malfunctions, or the network is subjected to electromagnetic interference, the protection function fails, posing a significant safety risk of protection failure.

[0006] Fourth, there is a lack of sensor self-testing and fault tolerance capabilities. Existing systems cannot automatically identify abnormal states such as sensor disconnection or malfunction. Faulty sensors may remain in a state of failure for a long time without being detected, creating a monitoring blind spot.

[0007] Therefore, there is an urgent need in this field for a cable fire monitoring and interlocking protection system that can be deployed in a differentiated and high-density manner for inherently weak areas, has multiple logical judgments that are resistant to environmental interference, has redundant and reliable execution layers, and has self-diagnostic functions. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by defining inherently weak areas of cables for differentiated high-density deployment, employing zoned isolation and dual-network redundant transmission, incorporating built-in environmental interference elimination algorithms, configuring dual redundant execution loops for communication and hard-wired connections, and integrating sensor self-diagnosis and fault management functions. This solves the technical problems of large monitoring blind spots, accidental shutdown due to environmental interference, single-point communication failure, and lack of self-testing and fault tolerance in existing technologies, and provides a targeted monitoring and multi-redundant interlocking protection system for electrolytic cell cables.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A targeted monitoring and multi-redundant interlocking protection system for electrolytic cell cables, characterized in that it includes: Targeted deployment of explosion-proof sensor array: Based on the physical structure and operating conditions of the electrolytic cell power supply cable, five inherently weak areas are identified, including the cable inlet contact area, terminal block area, cable tray corner stress area, cable trench corrosion area, and outgoing high-current connector area. Sensor units are deployed in these five inherently weak areas at differentiated densities. In actual use, the sensor units may include explosion-proof smoke sensors, temperature sensors, humidity sensors, etc. High-risk areas adopt redundant deployment of dual sensor units, while the next highest-risk areas adopt high-density deployment of single sensor units. Partition isolation and dual-network redundant transmission architecture: The explosion-proof sensor array is divided into multiple monitoring zones according to physical areas. Each zone is equipped with an independent area acquisition module. The area acquisition module and the upper-level control module adopt a dual-network redundant transmission architecture, including a physically independent first communication network and a second communication network. When a link failure occurs in either communication network, it automatically switches to the other communication network. Control module and environmental interference elimination algorithm: The control module is set separately from the area acquisition module. The control module has a built-in temperature and humidity threshold correction unit, a time-delay continuous filtering unit and a collaborative judgment algorithm unit. The collaborative judgment algorithm unit includes a single-point early warning non-stop sub-module, a multi-point over-limit sub-module in the same area and a neighboring area cross-cooperation sub-module. Dual Redundant Execution Layer of Communication and Passive Hard Wiring: Includes a communication interlocking circuit and an independent passive hard wiring safety circuit set in parallel. The communication interlocking circuit receives the communication shutdown command output by the control module through the industrial bus. The independent passive hard wiring safety circuit is independent of the industrial bus and the control module and directly receives the hard contact dry contact signal output by the control module through the shielded cable. The main power supply circuit of the electrolytic cell is cut off when either circuit is activated. The self-diagnosis and fault management unit includes a sensor disconnection detection submodule, a hierarchical branch priority disconnection electronic module, a fault tracing and storage submodule, and a remote push and authorized reset submodule.

[0010] Specifically, the differentiated deployment density corresponding to the above five inherently weak areas is as follows: Cable inlet contact area and high current outlet joint area: 2 sensing units are deployed at each connection point to form dual sensing unit redundancy; Terminal block area: 1 sensing unit is deployed for every 5 terminals; Cable tray corner stress area: 1 sensing unit is deployed at each corner point; Cable trench corrosion area: 1 sensing unit with anti-corrosion coating is deployed for every 10 meters.

[0011] Furthermore, in the dual-network redundant transmission architecture, the first communication network and the second communication network use different communication media and different routing paths to form redundant backups; the system has a built-in link status monitoring unit, which is used to periodically send heartbeat messages to detect the status of each link. When a link failure is detected, it automatically completes a seamless switch, and data acquisition is not interrupted during the switch.

[0012] Furthermore, the temperature and humidity threshold correction unit collects on-site temperature and humidity data in real time and dynamically adjusts the alarm thresholds of each sensing unit according to the preset temperature and humidity compensation curve to eliminate the influence of temperature and humidity changes on smoke detection.

[0013] The above temperature and humidity threshold correction is performed using the following formula: TH 修正 =TH 基准 ×[1+α_H×(H-H0)+α_T×(T-T0)] Among them, TH 基准 As the baseline threshold, H represents the measured humidity. H0 is the baseline humidity. α_H is the humidity correction factor; T is the measured temperature. T0 is the reference temperature. α_T is the temperature correction factor.

[0014] Furthermore, the delayed continuous filtering unit continuously samples the sensor unit signal, uses a median filtering algorithm to remove instantaneous spike interference, and sets a confirmation delay window. The signal only enters the next judgment stage if it continuously exceeds the limit within the delay window.

[0015] Furthermore, in the collaborative decision-making algorithm unit: The single-point early warning non-stop submodule: when the signal of a single sensing unit exceeds the early warning threshold, it only outputs early warning information and does not trigger shutdown; The multi-point over-limit submodule in the same area: when any two or more sensor units in the same monitoring zone exceed the warning threshold at the same time and for more than 10 seconds, it is determined to be a real fire and a shutdown command is triggered. The neighboring zone cross-coordination submodule: when one sensor unit in each of two adjacent monitoring zones exceeds the warning threshold simultaneously and this continues for more than 10 seconds, it is determined that the fire is spreading and a shutdown command is triggered.

[0016] Furthermore, the independent passive hard-wired safety circuit adopts a hardware output point that is independent of the main program of the control module and is powered by an independent power supply. When the industrial bus fails or the main program of the control module crashes, it can still independently execute the shutdown.

[0017] Furthermore, the sensor disconnection detection submodule periodically detects the current signal of each sensing unit circuit. When the signal exceeds the normal range, it determines that the sensing unit is disconnected or faulty, generates a fault alarm, and disables the shutdown trigger function of the sensing unit.

[0018] Furthermore, in the event of a fire, the graded branch priority disconnection electronic module prioritizes cutting off the power supply to the faulty branch according to the branch priority of the fault point, so as to preserve normal production in the non-faulty area to the greatest extent.

[0019] The system power outage is divided into three levels: Level 1 power outage: only the power supply to the electrolytic cell corresponding to the faulty branch is cut off; Level 2 power outage: when the adjacent area is triggered by cross-coordination after Level 1 power outage, the power supply to all electrolytic cells in the series where the faulty area is located is cut off; Level 3 power outage: when the fire is still not under control after Level 2 power outage, the power supply to all electrolytic cells in the plant is cut off.

[0020] Furthermore, the fault tracing and storage submodule records detailed information on all alarm events, shutdown events, and sensor unit fault events, including timestamps, location numbers, fault types, and triggering logic; the remote push and authorized reset submodule remotely pushes alarm information to the management personnel terminal and sets up an authorized reset function, which allows the system to be reset only after confirmation by authorized personnel.

[0021] The advantages and beneficial effects of this invention are as follows: 1. Targeted deployment in five vulnerable areas to eliminate monitoring blind spots: Differentiated high-density deployment is carried out in five inherent vulnerable areas: cable inlet contacts, terminal blocks, cable tray corner stress areas, cable trench corrosion areas, and outgoing high-current joints. Dual-sensor redundancy is used in high-risk areas, and high-density deployment is used in secondary high-risk areas. This achieves precise allocation of monitoring resources to high-risk areas and fundamentally eliminates monitoring blind spots.

[0022] 2. Partition isolation and dual-network redundancy ensure reliable communication. The partition isolation and dual-network redundancy anti-interference transmission architecture is adopted. The two networks are physically independent and have separate routing. Automatic and seamless switching is enabled in case of single link failure, ensuring reliable uploading of monitoring data and greatly improving the reliability of communication links.

[0023] 3. Temperature and humidity correction, filtering, and collaborative judgment to prevent false shutdowns. Temperature and humidity threshold correction eliminates the influence of environmental temperature and humidity, and delayed continuous filtering removes instantaneous peak interference. The collaborative judgment algorithm of "single-point early warning without shutdown + multi-point over-limit in the same area / cross-coordination in neighboring areas" effectively distinguishes between real fire and environmental interference, and completely solves the problem of false shutdown caused by single-point smoke interference from water vapor / dust.

[0024] 4. Dual redundancy of communication and passive hard-wiring ensures reliable power-off even when disconnected from the network. The communication interlock and independent passive hard-wiring safety circuit are connected in parallel, retaining the convenience of communication shutdown while possessing the inherent safety of hard-wiring shutdown. Even in the event of an industrial bus failure or PLC main program crash, the independent hard-wiring circuit can still reliably disconnect the main power supply circuit, achieving ultimate reliability of the protection function.

[0025] 5. Self-diagnosis and fault management eliminate monitoring blind spots. The sensor unit disconnection / fault self-diagnosis function can detect failed sensor units in real time and generate alarms, avoiding monitoring blind spots caused by sensor unit failure; the hierarchical branch priority power-off function minimizes the impact of downtime; the fault source tracing storage and remote push function provide complete support for accident analysis and emergency response. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall system architecture of the present invention; Figure 2 This is a flowchart of the control module and environmental interference removal algorithm of the present invention; Figure 3 This is a schematic diagram of the dual-redundant execution layer for communication and passive hard-wired connections in this invention. Figure 4 This is a flowchart of the self-diagnosis and fault management process of this invention; Detailed Implementation

[0027] The specific embodiments of the present invention will be further described below with reference to examples. These examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0028] An electrolytic cell cable targeted monitoring and multi-redundant interlocking protection system includes: The explosion-proof sensor array, strategically positioned to target five vulnerable areas, delineates five inherently vulnerable areas based on the physical structure and operating conditions of the electrolytic cell's power supply cables. Figure 1 As shown, it includes: Cable inlet contact area: the initial connection point where the cable enters the electrolytic cell; Terminal block area: The location of terminal blocks where multiple cables converge; The stress zone at the corner of the cable tray: the location where the cable tray turns from horizontal to vertical, with a turning radius of less than 10 times the cable diameter; Corrosion zone in cable trenches: Areas within cable trenches where water, dust, and corrosive gases accumulate; High-current connector area: High-current connection point on the outlet side of the electrolytic cell.

[0029] Explosion-proof smoke sensing units are deployed at differentiated densities in the five inherently weak areas. In the high-risk areas (incoming contact area and outgoing high current connector area), dual sensing units are redundantly deployed. In the secondary high-risk areas (terminal block area and cable tray corner stress area), single sensing units are deployed at high density. In the corrosive areas, dedicated sensing units with anti-corrosion coatings are deployed.

[0030] The explosion-proof sensor array is divided into multiple monitoring zones based on physical areas. Each zone is equipped with an independent area acquisition module. The area acquisition module and the upper-level control module adopt a dual-network redundant transmission architecture. The dual-network redundant transmission architecture includes a physically independent first communication network and a second communication network. The first and second communication networks use different communication media and different routing paths to form redundancy backup. Specifically, a fiber optic ring network and a shielded RS485 dual physically independent network can be used as the first and second communication networks, respectively. Each network has independent routing, independent power supply, and independent interface. It has built-in heartbeat detection and automatic seamless switching in case of single link failure. When a link failure occurs in either communication network, the system automatically and seamlessly switches to the other communication network without interrupting data acquisition during the switching process.

[0031] The control module and environmental interference elimination algorithm are separate from the area acquisition module, with the control module being built-in. (1) Temperature and humidity threshold correction unit: Real-time collection of on-site temperature and humidity data, and dynamic adjustment of the alarm threshold of each sensing unit according to the preset temperature and humidity compensation curve to eliminate the influence of temperature and humidity changes on smoke detection. (2) Delayed continuous filtering unit: The sensor unit signal is continuously sampled, and the median filtering algorithm is used to remove instantaneous spike interference. A confirmation delay window is set, and the signal will only enter the next judgment stage if it continues to exceed the limit within the delay window. (3) Collaborative decision-making algorithm unit, including: ① Single-point early warning non-stop submodule: When the signal of a single sensor unit exceeds the early warning threshold, it only outputs early warning information and does not trigger shutdown; ② For the multi-point over-limit submodule in the same area, when any two or more sensor units in the same monitoring zone exceed the warning threshold at the same time, it is determined to be a real fire and a shutdown command is triggered; ③ Neighboring area cross-coordination submodule: When one sensor unit in each of two adjacent monitoring zones exceeds the warning threshold at the same time, it is determined that the fire is spreading and a shutdown command is triggered.

[0032] A dual-redundant execution layer with both communication and passive hard-wired connections is provided. This execution layer includes a parallel communication interlocking circuit and an independent passive hard-wired safety circuit. Specifically: Communication interlocking circuit: Receives the communication shutdown command output by the control module via the industrial bus, and drives the first actuator to cut off the main power supply circuit of the electrolytic cell.

[0033] Independent passive hard-wired safety circuit: Independent of the industrial bus and control module, it directly receives hard-contact dry contact signals output by the control module through a shielded cable, driving the second actuator to cut off the main power supply circuit of the electrolytic cell.

[0034] The communication interlocking circuit and the independent passive hard-wired safety circuit are connected in parallel. The main power supply circuit can be cut off if either circuit is activated. When the industrial bus fails or the control module malfunctions, the independent passive hard-wired safety circuit can still independently shut down the system.

[0035] The system has a built-in self-diagnosis and fault management unit, which includes: The sensor disconnection detection submodule periodically detects the current signal of each sensing unit circuit. When the signal exceeds the normal range, it determines that the sensing unit is disconnected or faulty, generates a fault alarm, and disables the shutdown trigger function of the sensing unit.

[0036] The tiered branch priority disconnection electronic module, in the event of a fire, prioritizes cutting off power to the faulty branch based on its priority, thus preserving normal production in non-faulty areas to the greatest extent possible. Specifically, the system power outage is divided into three levels: Level 1 power outage: only the electrolytic cells corresponding to the faulty branch are disconnected; Level 2 power outage: when a Level 1 power outage is followed by cross-triggered power outages in adjacent areas, all electrolytic cells in the series containing the faulty area are disconnected; Level 3 power outage: if the fire is still not under control after a Level 2 power outage, all electrolytic cells in the plant are disconnected. The fault tracing and storage submodule records detailed information on all alarm events, shutdown events, and sensor unit fault events, including timestamps, location numbers, fault types, and triggering logic, forming a complete accident tracing chain.

[0037] The remote push and authorized reset submodule remotely pushes alarm and fault information to the management terminal and sets up an authorized reset function, which allows the system to be reset only after confirmation by authorized personnel.

[0038] Example 1: Targeted deployment in five vulnerable areas This embodiment takes the power supply cable of a 300kA electrolytic cell in a certain factory as the object, delineates five inherent weak areas and carries out differentiated targeted deployment.

[0039] 1. Definition of Five Inherent Weaknesses Z1 cable inlet contact area: the first connection point from the rectifier transformer outlet side to the electrolytic cell inlet end, the initial connection point, with the highest contact resistance, and prone to loosening due to vibration; Z2 terminal block area: The terminal block location where multiple cables converge, with multiple connection points converging; any looseness will cause overheating. Z3 cable tray corner stress zone: When the cable tray is turned from horizontal to vertical and the turning radius is less than 10 times the cable diameter, mechanical stress is concentrated and the insulation layer is prone to cracking. Z4 cable trench corrosion zone: a section in the cable trench where water, dust, and corrosive gases accumulate, accelerating the aging of the insulation layer and corroding the metal shielding layer. The Z5 high-current connector area is where a large current flows from the electrolytic cell outlet side to the next-level busbar connection point, generating the most heat.

[0040] 2. Differentiated Targeted Deployment Plan Z1 incoming contact area: This is a high-risk area, with one contact per contact. It is explosion-proof and air-suction type with dual redundant sensing units. Z2 terminal block area: classified as secondary high risk, one terminal block for every 5 terminals, explosion-proof type, single sensor unit encryption; Z3 cable tray corner stress zone: classified as secondary high risk, 1 per corner, explosion-proof air-suction type, single sensor unit encrypted; Z4 cable trench corrosion zone: classified as medium risk, one zone every 10 meters, dedicated to anti-corrosion coating, single sensor unit; Z5 Outgoing High Current Connector Area: This area is classified as high-risk, with one connector per area. It is an explosion-proof, air-suction type with redundant dual sensing units.

[0041] 3. Deployment Instance Taking the Z1 inlet contact area as an example, this electrolytic cell has four inlet contacts, each equipped with two aspirating smoke sensing units, for a total of eight sensing units. The sampling tube extends to the contact joint gap, with the sampling hole facing the contact surface between the contact and the cable lug. The sampling tubes of the two redundant sensing units are respectively laid on different sides of the contact to avoid simultaneous failure due to local airflow obstruction.

[0042] Taking the Z2 terminal block area as an example, this area has a total of 20 terminals. One explosion-proof smoke detector is deployed for every 5 terminals, for a total of 4 detectors. The detectors are installed 30cm directly above the terminal block, with the probes facing the terminal block.

[0043] Example 2: Partition Isolation and Dual-Network Redundancy Transmission Architecture In this embodiment, the explosion-proof sensor array is divided into 4 monitoring zones according to physical area. Each zone is equipped with an independent area acquisition module (D1-D4). The area acquisition module and the upper-level control module adopt a dual-network redundant transmission architecture.

[0044] 1. Partitioning Area A belongs to the Z1 incoming contact area with 8 sensing units corresponding to the D1 acquisition module; Area B belongs to the Z2 terminal block area with 4 sensing units corresponding to the D2 acquisition module; Area C belongs to the Z3 cable tray corner stress area + Z4 cable trench corrosion area with 6 sensing units corresponding to the D3 acquisition module; Area D belongs to the Z5 outgoing high current connector area with 4 sensing units corresponding to the D4 acquisition module.

[0045] 2. Dual-network redundant transmission architecture First communication network: adopts fiber optic Ethernet ring network with a transmission rate of 100Mbps. The fiber optic route is laid along the upper layer of the cable tray to avoid strong electromagnetic interference sources. The second communication network uses shielded twisted-pair RS485 bus with a transmission rate of 115.2kbps. The route is laid along the independent cable tray under the cable tray and is physically isolated from the fiber optic network. Each area acquisition module and control module is equipped with two independent communication interfaces, which are connected to two different communication networks. The two networks are two independent networks using different communication media and different laying paths. The two networks have independent power supply and independent routing, and there is no common fault point.

[0046] 3. Redundancy switching mechanism Employing a Parallel Redundancy Protocol (PRP), each area acquisition module simultaneously transmits the same data frames through two communication networks, with each data frame carrying a unique sequence number. The control module simultaneously receives data from both networks, identifies duplicate frames by sequence number, and selects the first arriving frame for processing. Even if one network experiences a link failure, the other network continues to transmit normally, achieving seamless redundancy with zero packet loss and zero handover time.

[0047] 4. Link Status Monitoring Each communication interface has a built-in link status monitoring unit that sends a heartbeat message every 100ms. If no heartbeat is received for three consecutive times, the link is determined to be faulty. The system automatically records the fault information, generates a communication alarm, and pushes it to the management terminal.

[0048] Example 3: Control Module and Environmental Interference Removal Algorithm like Figure 2 As shown, the control module uses an industrial PLC and is located separately from the area acquisition module in the central control room. The control module has three core algorithm units built in.

[0049] 1. Temperature and humidity threshold correction unit Temperature and humidity sensors are deployed at key locations on-site to collect ambient temperature and humidity data in real time. The control module has a built-in temperature and humidity compensation curve to dynamically adjust the alarm thresholds of each smoke sensor. The warning threshold is 15 mg / m³ 3Humidity ≥80%, 18 mg / m 3 (Up 20%) The warning threshold is 15 mg / m³ 3 Temperature ≥40℃, 16.5 mg / m 3 (Up 10%) The shutdown threshold is 30 mg / m³ 3 Humidity ≥80%, 33 mg / m 3 (Up 10%) The shutdown threshold is 30 mg / m³ 3 Temperature ≥40℃, 30 mg / m 3 (constant).

[0050] Correction formula: TH 修正 =TH 基准 ×[1+α_H×(H-H0)+α_T×(T-T0)] Among them, TH 基准 Here, H is the reference threshold, H0 is the measured humidity, α_H is the reference humidity, and T is the measured temperature, T0 is the reference temperature, and α_T is the temperature correction factor. Where α_H is the humidity correction factor of 0.005 and α_T is the temperature correction factor of 0.002.

[0051] 2. Delayed Continuous Filtering Unit The signal from each sensing unit is continuously sampled at a sampling frequency of 10Hz. A sliding median filtering algorithm is used with a window width of 10 sampling points to eliminate instantaneous spike interference. The filtered signal must continuously exceed the limit within a 3-second confirmation delay window before proceeding to the next judgment stage.

[0052] 3. Collaborative Decision Algorithm Unit (1) Single-point early warning non-stop submodule When the filtered signal of a single sensing unit exceeds the warning threshold, the system only generates a warning message and displays the alarm point on the human-machine interface, without triggering a shutdown command, thus avoiding false shutdown caused by single-point environmental interference.

[0053] (2) Multiple over-limit sub-modules in the same area Logical expression: IF (Count_{i in Zone} (Value_i ≥ Threshold_warn) ≥ 2) AND (Duration≥ 10s) THEN Output_Stop When any two or more sensor units in the same monitoring zone simultaneously exceed the warning threshold and this continues for more than 10 seconds, it is determined to be a real fire and a shutdown command is triggered.

[0054] (3) Neighbor cell cross-cooperation submodule Logical expression: IF (Zone_A has over-limit sensor units) AND (Zone_B has over-limit sensor units) AND (Zone_A and Zone_B are adjacent) AND (Number of over-limit sensor units ≥ 2, located in two different zones) AND (Duration ≥ 10s) THEN Output_Stop If one sensor unit in each of two adjacent monitoring zones exceeds the warning threshold simultaneously for more than 10 seconds, it is determined that the fire is spreading and a shutdown command is triggered.

[0055] 4. Algorithm Performance Verification Single-point water vapor interference: instantaneous jump to 35 mg / m³ 3 If the duration is less than 1 second, delay filtering will eliminate the alarm. Single-point dust fall: fluctuates around the warning threshold, does not stably exceed the limit, only issues a warning, does not stop the system; Multiple real fires in the same area: Two sensor units rise synchronously and trigger shutdown after 10 seconds of stable over-limit operation; Neighboring zone cross-spread: After one sensor unit in each adjacent zone exceeds the stable limit for 10 seconds, a shutdown is triggered.

[0056] Example 4: Dual Redundancy Execution Layer with Communication and Passive Hardwiring like Figure 3 As shown, the execution layer adopts a dual-redundancy architecture with a communication interlocking circuit and an independent passive hard-wired safety circuit connected in parallel.

[0057] 1. Communication interlocking circuit The control module sends a communication stop command to the execution unit via the Profibus DP bus.

[0058] The execution unit has a built-in bus communication module that parses instructions and drives the first intermediate relay K1. The normally open contact of K1 is connected to the shunt trip coil circuit of the DC circuit breaker of the electrolytic cell.

[0059] 2. Independent passive hard-wired safety circuit The control module simultaneously outputs an independent hard-contact dry-contact signal, which is transmitted directly to the execution unit via a shielded cable without passing through any intermediate communication equipment. After opto-isolation, the signal drives the second intermediate relay K2. The normally open contact of K2 is connected in parallel with the normally open contact of K1 and then connected to the shunt trip coil circuit.

[0060] 3. Independent power supply and failure protection The hard-wired circuit is powered by a 24V DC power supply independent of the PLC system, drawn from a dedicated battery in the circuit breaker control circuit. When the PLC main program crashes, the dry contact signals of the hard-wired circuit can still be directly output through the hardware output points of the control module. When the industrial bus fails, the communication interlock circuit fails, but the hard-wired circuit can still independently execute a shutdown.

[0061] 4. Dual-redundancy execution reliability verification Normal operating conditions are displayed as "Normal" or "Normal", with communication commands taking priority; bus faults are displayed as "Failure" or "Normal", triggered by hard wiring; PLC crashes are displayed as "Failure" or "Normal", triggered by hard wiring; simultaneous dual-circuit failures are displayed as "Failure", "Failure", or "Failure", requiring manual emergency response.

[0062] Example 5: Self-diagnosis and fault management unit like Figure 4 As shown, the system has built-in complete self-diagnosis and fault management functions.

[0063] 1. Sensor unit disconnection and fault self-diagnosis Each sensing unit loop outputs a 4-20mA current signal, and the area acquisition module periodically detects the loop current. Normal range: 3.5mA ~ 20.5mA; Disconnection fault: < 3.5mA, lasting more than 3 seconds; Short circuit fault: > 20.5mA, lasting more than 3 seconds; Upon detecting a fault, a fault alarm is immediately generated, and the faulty sensor unit number is displayed on the human-machine interface. At the same time, the shutdown trigger function of the sensor unit is automatically disabled to avoid accidental shutdown due to sensor unit failure. Once the faulty sensor unit recovers, the disable function is automatically removed.

[0064] 2. Prioritize power disconnection for tiered branch circuits. When a fire occurs and a shutdown is required, the system implements a tiered power-off strategy according to the priority of the branch where the fault point is located: Level 1 power failure: Multiple points in the same area of ​​the electrolytic cell corresponding to the faulty branch are triggered by exceeding the limit. Level 2 power failure: All electrolytic cells in the series where the fault area is located are triggered in a cross-coordinated manner after the Level 1 power failure; Level 3 power outage: The fire was still out of control after a Level 2 power outage affecting the entire plant's electrolytic cells; The tiered power outage strategy minimizes the impact of downtime on production.

[0065] 3. Fault source tracing and storage The system has a built-in industrial-grade database that records complete information about all events. Alarm event, timestamp, location number, sensor unit value, trigger threshold, temperature and humidity correction value; Shutdown event, timestamp, triggering logic (single point / multi-point / neighbor cell), list of over-limit sensing units, numerical curve; Fault event, timestamp, fault type (open circuit / short circuit / communication failure), fault location, recovery time; Operation event, timestamp, operator, operation content (reset / bypass / threshold modification); All data storage periods are no less than 3 years, and multi-dimensional retrieval by time, location, event type, and other dimensions is supported.

[0066] 4. Remote push and authorization reset Alarm information, shutdown information, and fault information are pushed in real time via 4G / 5G network to: the central control room operation station, the on-duty engineer's mobile APP, and the workshop director / safety director's WeChat enterprise account.

[0067] The push notification includes: alarm location, real-time data, and on-site video screenshots.

[0068] The reset function requires authorization: Warning reset: operator-level permission; Shutdown reset: engineer-level permission, requires dual confirmation; Threshold modification: system administrator-level permission, requires approval process; All reset operations are recorded with the operator, operation time, and operation reason.

[0069] Example 6: Overall System Workflow Scenario 1: Single-point environmental interference (moisture / dust) 1. Due to water vapor condensation, the signal of sensor unit S01 instantly jumped to 35 mg / m³. 3 ; 2. Delayed continuous filtering units identify instantaneous spikes and remove them using median filtering; 3. If the signal does not exceed the limit continuously within the 3-second delay window, the next step of judgment will not be performed; 4. The system does not generate any alarms, and the electrolytic cell is operating normally.

[0070] Scenario 2: Single-point real-time early warning (initial overheating) 1. Due to a loose wiring terminal in sensor unit S02, the smoke concentration slowly increased to 16 mg / m³. 3 ; 2. The temperature and humidity correction unit adjusts the warning threshold to 16.5 mg / m³ based on the current humidity of 75%. 3 ; 3. Measured value: 16 mg / m³ 3 The revised warning threshold has not been reached; monitoring will continue. 4. When the concentration rises to 17 mg / m³ 3 If the warning threshold is exceeded and remains exceeded for more than 3 seconds; 5. The single-point early warning non-stop submodule is triggered, generates early warning information, and pushes it to the mobile phone of the on-duty personnel; 6. On-duty personnel retrieve on-site video footage for confirmation, arrange for maintenance personnel to handle the situation, and ensure the electrolytic cell remains operational without shutting down.

[0071] Scenario 3: Multiple real fires in the same area 1. Two adjacent terminals in the terminal block area (Area B) overheat simultaneously, causing the smoke concentration in sensing units S05 and S06 to rise to 18 mg / m³. 3 and 22mg / m 3 ; 2. Both signals exceed the warning threshold and remain stable. 3.10 seconds later, multiple over-limit sub-modules in the same area were triggered; 4. The control module simultaneously outputs a communication stop command and a hard-wired dry contact signal; 5. The communication interlocking circuit operates normally, cutting off the power supply to the faulty electrolytic cell; 6. Hard-wired circuits serve as backups, remaining in standby mode even when not activated; 7. The system records downtime events, pushes them to administrators, and triggers video linkage.

[0072] Scenario 4: Emergency shutdown due to communication network failure 1. The industrial bus was interrupted due to electromagnetic interference, and the communication interlocking circuit failed. 2. At this time, multiple real fires occur in the same area, and the control module still outputs hard-wired dry contact signals; 3. An independent passive hard-wired safety circuit directly drives the intermediate relay K2; 4. When the normally open contact of K2 closes, the shunt trip coil is energized, and the circuit breaker trips; 5. The electrolytic cell can be shut down reliably, and the protection functions will continue to operate normally even if the communication network fails completely.

[0073] Scenario 5: Self-diagnosis of sensor unit faults 1. Due to a broken cable, the circuit current of sensor unit S03 dropped to 2.8mA; 2. If the self-diagnostic unit detects a current of <3.5mA for 3 seconds, it determines that there is a wire breakage fault; 3. The system generates a fault alarm and displays "S03 Disconnection Fault" on the human-machine interface; 4. Automatically disable the shutdown trigger function of S03 to avoid accidental shutdown due to sensor unit failure; 5. Push fault information to the mobile phones of maintenance personnel and arrange for the replacement of the sensor unit; 6. After replacement, the self-diagnostic unit detected that the current had returned to the normal range and automatically unshielded the shield.

[0074] This interlocking protection system can be widely used in non-ferrous metal electrolysis industries such as electrolytic aluminum, electrolytic copper, and electrolytic magnesium, and can also be used in high-current DC power supply scenarios such as chlor-alkali industry and electroplating industry.

[0075] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pot cable targeted monitoring with multiple redundant interlocked protection system, characterized by, include: The targeted explosion-proof sensor array is divided into several detection zones according to the physical structure and operating conditions of the power supply cable of the electrolytic cell. Sensor units are deployed in the detection zones. The sensor units are deployed with differentiated density according to the physical structure and operating conditions of the cable. High-risk areas adopt redundant deployment of dual sensor units, and secondary high-risk areas adopt high-density deployment of single sensors. The system employs a partitioned isolation and dual-network redundant transmission architecture. The partitioned isolation involves dividing the explosion-proof sensor array into multiple independent monitoring zones based on physical areas. Each monitoring zone corresponds to a zone acquisition module, used to acquire signals from the sensor units within that zone. The zone acquisition module is simultaneously connected to the upper-level control module via a dual-network redundant transmission architecture, which includes two physically independent communication networks: a first communication network and a second communication network. Both communication networks feature automatic, seamless switching in case of link failure. The control module and the environmental interference elimination algorithm are set separately from the area acquisition module. The control module has a built-in temperature and humidity threshold correction unit, a time-delay continuous filtering unit, and a collaborative judgment algorithm unit. The collaborative judgment algorithm unit includes a single-point early warning non-stop submodule, a multi-point over-limit submodule in the same area, and a neighboring area cross-cooperation submodule. The dual-redundant execution layer of communication interlock and passive hard-wired circuit includes a communication interlock circuit and an independent passive hard-wired safety circuit set in parallel. The communication interlock circuit receives the communication shutdown command output by the control module through the industrial bus. The independent passive hard-wired safety circuit is independent of the industrial bus and the control module and directly receives the hard contact dry contact signal output by the control module through the shielded cable. Any trigger operation will cut off the main power supply circuit of the electrolytic cell. The self-diagnosis and fault management unit includes a sensor disconnection detection submodule, a hierarchical branch priority disconnection electronic module, a fault tracing and storage submodule, and a remote push and authorized reset submodule.

2. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The detection zones include the cable inlet joint area, terminal block area, cable tray corner stress area, cable trench corrosion area, and outgoing high current joint area.

3. A multi-redundant interlocked protection system for targeted monitoring of an electrolytic cell cable according to claim 1, wherein, Two sensing units are configured at each connection point in the cable inlet contact area and the high current outlet connector area to form a dual redundant sensing unit; sensing units are arranged at fixed intervals in the terminal block area according to the number of terminals; sensing units are arranged at each corner point in the cable tray corner stress area; and sensing units with anti-corrosion coatings are arranged at preset intervals in the cable trench corrosion area.

4. The electrolytic cell cable targeted monitoring and multi-redundant interlocking protection system according to claim 1, characterized in that, The first and second communication networks are two independent networks using different communication media and different laying paths to form a redundant backup; the dual-network redundant transmission architecture has a built-in link status monitoring unit, which is used to periodically send heartbeat messages to detect the status of each link. When a link failure is detected, it automatically completes a seamless switch, and the data acquisition is not interrupted during the switch process.

5. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The temperature and humidity threshold correction unit collects on-site temperature and humidity data in real time and dynamically adjusts the alarm thresholds of each sensing unit according to a preset temperature and humidity compensation curve to eliminate the influence of temperature and humidity changes on the detection signal. The temperature and humidity threshold correction uses the following formula: TH 修正 = TH 基准 × [1 + α_H × (H - H0) + α_T × (T - T0)] Among them, TH 基准 H is the baseline threshold, H is the measured humidity, H0 is the baseline humidity, and α_H is the humidity correction factor; T is the measured temperature, T0 is the baseline temperature, and α_T is the temperature correction factor.

6. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The delayed continuous filtering unit continuously samples the signal from the sensing unit and uses a median filtering algorithm to remove instantaneous spike interference. It only proceeds to the next judgment stage when the signal continuously exceeds the limit within the delay window.

7. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The collaborative decision-making algorithm unit is configured to execute the following decision-making logic: Single-point early warning non-stop submodule: When the signal of a single sensor unit exceeds the early warning threshold, only early warning information is output, and no shutdown is triggered; Multiple Over-Limit Sub-module in the Same Zone: When two or more sensor units in the same zone exceed the limit and continue to exceed the set time, it is determined to be a real fire and a shutdown command is triggered. Neighboring Zone Cross-Coordination Submodule: When one sensor unit in each adjacent zone exceeds the limit and continues for a set time, it is determined that the fire is spreading and a shutdown command is triggered.

8. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The independent passive hard-wired safety circuit uses an independent power supply and independent hardware contacts, and can independently and reliably perform power-off actions without communication networks and main control programs.

9. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The sensor disconnection detection submodule periodically detects the current signal of each sensing unit circuit. When the signal exceeds the normal range, it determines that the sensing unit is disconnected or faulty, generates a fault alarm, and locks the shutdown trigger function of the sensing unit.

10. A multi-redundant interlocked protection system for targeted monitoring of an electrolyzer cable according to claim 1, wherein, The hierarchical branch priority disconnection electronic module is configured to: in the event of a fire, prioritize disconnecting the power supply to the faulty branch based on the branch priority of the fault location. The system disconnection logic is divided into three levels: Level 1 power failure: Only the power supply to the electrolytic cell corresponding to the faulty branch is cut off; Level 2 power failure: If the cross-coordination condition of the adjacent area is triggered after the Level 1 power failure, the power supply to all electrolytic cells in the series where the fault area is located will be cut off. Level 3 power outage: If the fire is determined to continue after Level 2 power outage, the power supply to all electrolytic cells in the plant will be cut off.

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