Multi-parameter monitoring type low-voltage complete distribution box based on composite switch control

Abstract

The invention relates to the technical field of electrical equipment, and discloses a multi-parameter monitoring type low-voltage complete distribution box based on combination switch control, which comprises a box body, a phase change hydraulic driving base is fixedly connected in the box body, and a combination switch is mounted on the phase change hydraulic driving base. A heat dissipation surface of the combination switch is connected with a heat conduction surface of the phase change hydraulic driving base, a main power rod extending to the outside of the phase change hydraulic driving base is arranged in the phase change hydraulic driving base, and the phase change hydraulic driving base is filled with a heat-sensitive phase change medium used for driving the main power rod to move; and when the heat-sensitive phase change medium absorbs heat generated by the combination switch and reaches a phase change temperature. The base is driven through phase change hydraulic pressure, and the equipment can convert waste heat generated in the operation process of the combination switch into high-precision mechanical displacement. According to the on-demand heat dissipation mode, zero-energy-consumption operation is achieved, energy waste and mechanical abrasion caused by full-time operation of a traditional fan are avoided, and the energy efficiency ratio and reliability of the system are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment technology, specifically to a multi-parameter monitoring low-voltage switch box based on composite switch control. Background Technology

[0002] With the rapid development of modern industrial automation and smart grids, low-voltage switchgear, as the nerve endings of power distribution and control, is carrying increasingly higher power densities. During the high-load operation of core power devices such as composite switches, thermal management has become the "Achilles' heel" restricting the reliability and lifespan of the equipment.

[0003] Currently, conventional heat dissipation solutions for electrical distribution boxes are caught in a dilemma between "passive inefficiency" and "active high risk." Traditional natural ventilation relies on air convection, which has extremely limited heat dissipation capacity and is unable to cope with heat accumulation under peak loads, easily leading to overheating, derating, or even damage to components. Although some equipment has introduced electrically driven fans for forced air cooling, this introduces new sources of failure: the fans themselves require continuous power and have a limited lifespan. More critically, continuous negative pressure suction draws large amounts of dust and lint into the cabinet. These contaminants easily clog the inlet filters, and without frequent manual cleaning and replacement, the clogged filters can actually form an insulating layer, causing the cabinet temperature to spike uncontrollably. However, in actual operation and maintenance, relying on manual inspections to replace filters is not only costly but also often delayed, making it difficult to maintain the equipment in optimal heat exchange conditions.

[0004] Furthermore, protection against electrical fires is a major weakness of current technology. Existing fire prevention measures largely rely on smoke or heat detectors in conjunction with electrically controlled fire extinguishing devices. However, this "electrically controlled" logic contains an inherent paradox: when a serious electrical short circuit or poor contact causes a fire, it is often accompanied by a power outage in the power distribution system or the burnout of the control circuit, causing the fire extinguishing system to fail due to power loss at the moment when it is most needed. At the same time, conventional fire extinguishing devices are usually triggered after an open flame has appeared, which is a reactive measure and lacks a "quasi-fuse" protection mechanism that can force physical intervention before the temperature exceeds the critical safety value but before it develops into a large fire.

[0005] In terms of fault monitoring, traditional methods mostly rely on NTC thermistors to monitor the temperature at the monitoring point. However, in complex electromagnetic environments, sensor signals are easily interfered with, and a single temperature data point cannot distinguish between "normal load temperature rise" and "abnormal heating caused by poor contact." For example, when the current is very small but the temperature is very high, it often means that the wiring terminals are loose, but existing systems cannot accurately identify such hidden faults, causing potential hazards to remain for a long time and eventually lead to accidents. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a multi-parameter monitoring low-voltage switchgear based on composite switch control. This solves the contradiction between high energy consumption and irreversible degradation of heat dissipation efficiency over time due to dust accumulation and blockage in traditional active cooling mechanisms under long-term high-load operation, as well as the maintenance pain point of relying heavily on frequent manual maintenance of the air inlet filter. Simultaneously, it addresses the reliability problem of traditional electrical fire protection systems, which rely heavily on external power supplies and electronic control circuits, making them unable to effectively extinguish fires in extreme scenarios involving severe electrical faults or control failures that cause power outages. Furthermore, this invention overcomes the limitations of conventional single-temperature monitoring methods, which have weak anti-interference capabilities in complex electromagnetic environments and struggle to accurately distinguish between normal load temperature rise and abnormal heating due to contact faults. It achieves adaptive thermal management, self-cleaning without external interference, and proactive safety defense throughout the equipment's entire lifecycle.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a multi-parameter monitoring low-voltage switchgear based on composite switch control, comprising a cabinet, a phase-change hydraulic drive base fixedly connected inside the cabinet, a composite switch mounted on the phase-change hydraulic drive base, with the heat dissipation surface of the composite switch and the heat conduction surface of the phase-change hydraulic drive base connected. The phase-change hydraulic drive base contains a main power rod extending to its exterior, and is filled with a heat-sensitive phase-change medium for driving the main power rod. When the heat-sensitive phase-change medium absorbs heat generated by the composite switch and reaches the phase-change temperature, it expands in volume, driving the main power rod to produce an outward linear extension displacement. A reset mechanism is also provided between the main power rod and the phase-change hydraulic drive base, used to drive the main power rod to retract and reset through elastic restoring force when the temperature decreases. The cabinet also contains a heat dissipation subsystem, a cleaning subsystem, and a trigger-type fire extinguishing system, all three of which are synchronously driven by the main power rod.

[0008] Preferably, the phase change hydraulic drive base has a chamber, in which a piston is slidably sealed. A heat-sensitive phase change medium is filled between the piston and the chamber. One end of the active force rod is fixedly connected to the center of the piston, and the other end passes through the phase change hydraulic drive base. The outer wall of the active force rod is slidably connected to the phase change hydraulic drive base.

[0009] Preferably, the reset mechanism includes a limiting block, which is centrally sleeved and fixedly connected to the outer wall of the main force rod. The outer wall of the main force rod is also sleeved with a reset spring, which is located between the limiting block and the phase change hydraulic drive base, and both ends of the reset spring are fixedly connected to both of them.

[0010] Preferably, the heat dissipation subsystem includes a ventilation window on the back panel of the enclosure, a mechanical louver is embedded and fixedly connected to the ventilation window, a gear is fixedly connected to the opening and closing shaft of the mechanical louver, a rack is meshed with the gear teeth, and the root of the rack is fixedly connected to the outer wall of the drive rod. When the drive rod extends, it drives the gear to rotate and causes the blades of the mechanical louver to flip, thus opening the mechanical louver. When the drive rod retracts, it drives the blades of the mechanical louver to flip in the opposite direction, thus closing the mechanical louver.

[0011] Preferably, the cleaning subsystem includes a filter assembly with a dual-roll structure, one roll being a take-up roll and the other a feed roll, connected by a filter. Part of the filter is wound around the feed roll, and the unfolded filter covers the air inlet at the bottom of the housing. This part of the filter penetrates the housing and covers the outer wall of the housing. A damping clamp is fixedly connected at this penetration point, through which the filter passes and is held. The damping clamp provides damping for the movement of the filter and seals the penetration point. The end of the take-up roll is provided with a one-way ratchet mechanism, which is driven by a drive rod. When the drive rod extends, the one-way ratchet mechanism is in an engaged transmission state, using the extension stroke to drive the take-up roll to rotate and refresh the filter. When the drive rod retracts, the one-way ratchet mechanism is in an idle slip state.

[0012] Preferably, the one-way ratchet mechanism includes a ratchet, the center of which is fixedly connected to the end of the take-up reel, and a rocker arm is rotatably connected to the center of the ratchet. One end of the rocker arm is provided with a pawl, and the other end is rotatably connected to an extension rod, which is fixedly connected to the drive rod.

[0013] Preferably, the trigger-type fire extinguishing system includes a pressurized fire extinguishing device, which is suspended from the top of the housing. Its trigger end is externally equipped with a spring-loaded striker assembly and a stroke-triggered release latch. The spring-loaded striker assembly is in a pre-compressed, energy-storing state and is limited by the stroke-triggered release latch. The stroke-triggered release latch is fixedly connected to the main force rod via a pull rope with a free stroke. When the extension displacement of the main force rod is within the normal heat dissipation range, the pull rope moves within the free stroke and does not trigger the latch. When the extension displacement of the main force rod exceeds a set extreme high-temperature threshold, the main force rod drives the stroke-triggered release latch to release the spring-loaded striker assembly, causing its striker to strike the trigger end of the pressurized fire extinguishing device and release the extinguishing medium.

[0014] Preferably, the housing is further provided with a displacement monitoring unit and a current transformer, both of which are electrically connected to the data processing unit. The displacement monitoring unit is used to detect the linear displacement of the main force rod in real time, and the current transformer is used to detect the loop current of the composite switch. The data processing unit is configured to perform fault diagnosis based on the following logic: If the loop current is zero or at an unloaded level, and the displacement of the main force rod is continuously greater than the preset safety threshold, it is determined to be non-load-related heating caused by a contact fault or internal short circuit. If the circuit current is at the rated or overload level, and the displacement of the main force rod is significantly lower than the theoretical expansion value, it is determined that the thermal drive mechanism has failed or the phase change medium is leaking.

[0015] This invention provides a multi-parameter monitoring low-voltage switchgear box based on composite switch control. It has the following advantages: 1. This invention utilizes a phase-change hydraulic drive base, enabling the device to convert waste heat generated during the operation of the composite switch into high-precision mechanical displacement. This design perfectly synchronizes the operation of the cooling system with the working conditions of the heat source; the higher the load and the greater the heat generation, the larger the opening angle of the mechanical louvers and the smoother the cooling airflow. This on-demand cooling mode not only achieves zero-energy operation but also avoids the energy waste and mechanical wear caused by the continuous operation of traditional fans, significantly improving the system's energy efficiency ratio and reliability. Simultaneously, through the cooperation of a unidirectional ratchet mechanism and a double-spindle structure, the retraction stroke of the main lever is converted into a filter replacement action. This means that the filter is automatically replaced every time the device completes a full working thermal cycle. This mechanism fundamentally solves the problem of filter heat dissipation efficiency degradation due to long-term dust accumulation, achieving long-term maintenance-free operation and ensuring the air inlet remains clean with low air resistance. The phase-change hydraulic drive base combines the functions of a power source and a high-efficiency heat sink. Made of a high thermal conductivity metal and tightly fitted to the composite switch, it ensures rapid response to temperature changes while also acting as a heat sink. All mechanical subsystems (louvers, filters, fire extinguishing) are integrated around this base, which not only saves valuable installation space inside the cabinet, but also simplifies the transmission chain path and improves the overall device's vibration resistance and mechanical robustness.

[0016] 2. This invention, by setting a "safe temperature threshold displacement range" and an idle travel pull rope structure, enables the system to accurately distinguish between normal high-temperature operation and extreme fault conditions. In the event of poor contact or a short circuit causing the temperature to exceed the limit, the overextended main power rod will directly release the spring-loaded striker via a mechanical interlock, puncturing the pressurized fire extinguishing device. This triggering method is completely independent of electricity and control signals. Even in extreme disasters such as a complete power outage in the distribution box or a burnt-out control board, it can still rely on physical laws to extinguish the fire at the critical point of outbreak.

[0017] 3. By comparing loop current (characterizing load rate) with active rod displacement (characterizing actual heat accumulation), the data processing unit of this invention can accurately eliminate environmental interference and normal temperature rise, and keenly identify contact faults of "low current and high heat" or drive mechanism failures of "high current and low heat". This physical logic-based cross-validation significantly reduces the false alarm rate and false negative rate, providing maintenance personnel with highly confident guidance on equipment health status. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present invention; Figure 2 This is a three-dimensional schematic diagram of the box body in this invention; Figure 3 This is a schematic diagram of the heat dissipation subsystem in this invention; Figure 4 This is a schematic diagram of the cleaning subsystem in this invention; Figure 5 for Figure 4 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the phase change hydraulic drive base in this invention.

[0019] The components include: 1. Housing; 2. Phase change hydraulic drive base; 201. Chamber; 3. Drive rod; 4. Piston; 5. Limiting block; 6. Return spring; 7. Mechanical louver; 8. Gear; 9. Rack; 10. Filter assembly; 1001. Take-up reel; 1002. Feed reel; 1003. Filter; 11. Damped clamp; 12. Ratchet; 13. Rocker arm; 14. Pawl; 15. Extension rod; 16. Pressurized fire extinguishing device; 17. Spring-charged firing pin assembly; 18. Stroke-triggered release latch; 19. Pull rope. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see the appendix Figure 1 -Appendix Figure 6This invention provides a multi-parameter monitoring low-voltage switchgear control box based on a composite switch, comprising a box body 1, a phase-change hydraulic drive base 2 fixedly connected inside the box body 1, a composite switch mounted on the phase-change hydraulic drive base 2, with the heat dissipation surface of the composite switch in contact with the heat conduction surface of the phase-change hydraulic drive base 2, a main power rod 3 extending to the outside of the phase-change hydraulic drive base 2, and the inside of the phase-change hydraulic drive base 2 filled with a heat-sensitive phase-change medium for driving the movement of the main power rod 3. When the heat-sensitive phase-change medium absorbs the heat generated by the composite switch and reaches the phase-change temperature, it expands in volume to drive the main power rod 3 to produce an outward linear extension displacement. A reset mechanism is also provided between the main power rod 3 and the phase-change hydraulic drive base 2, which is used to drive the main power rod 3 to retract and reset through elastic restoring force when the temperature decreases. The box body 1 also includes a heat dissipation subsystem, a cleaning subsystem, and a trigger-type fire extinguishing system, all of which are synchronously driven by the main power rod 3.

[0022] The enclosure 1 is equipped with mounting columns or beams to support the electrical components inside, such as the main circuit breaker, neutral bar, fuses, single-circuit circuit breakers, and data detection and processing units. The composite switch is not directly fixed to the mounting columns or beams, but is instead fixedly connected to them via a phase-change hydraulic drive base 2. The heat dissipation surface of the composite switch is in close contact with the heat-conducting surface of the phase-change hydraulic drive base 2. Furthermore, thermally conductive silicone grease or phase-change thermally conductive pads are embedded at the contact point to eliminate contact thermal resistance and ensure that the heat generated by the power devices inside the composite switch can be quickly and without damage transferred to the phase-change hydraulic drive base 2.

[0023] The phase-change hydraulic drive base 2 has a chamber 201 inside, and a piston 4 is slidably sealed inside the chamber 201. A heat-sensitive phase-change medium is filled between the piston 4 and the chamber 201. One end of the drive rod 3 is fixedly connected to the center of the piston 4, and the other end passes through the phase-change hydraulic drive base 2. The outer wall of the drive rod 3 is slidably connected to the phase-change hydraulic drive base 2. The reset mechanism includes a limiting block 5, which is centrally fitted and fixedly connected to the outer wall of the drive rod 3. A reset spring 6 is also fitted on the outer wall of the drive rod 3. The reset spring 6 is located between the limiting block 5 and the phase-change hydraulic drive base 2, and both ends of the reset spring 6 are fixedly connected to both.

[0024] The phase-change hydraulic drive base 2 is made of a metal material with high thermal conductivity, preferably cast aluminum alloy or copper alloy. Its upper surface is precision milled to form a flat mounting surface to ensure minimal thermal resistance contact with the heat dissipation surface of the composite switch.

[0025] The phase-change hydraulic drive base 2 has a sealed pressure chamber 201 inside, the volume of which is precisely calculated based on the required mechanical stroke and thrust. The chamber 201 is filled with a heat-sensitive phase-change medium. In this embodiment, the heat-sensitive phase-change medium is a mixture of industrial-grade special paraffin and metal powder, or a heat-sensitive memory polymer with a specific phase-change temperature point. The solid-liquid phase-change temperature range of this medium is configured to match the optimal operating temperature range of the composite switch, for example, set between 45 degrees Celsius and 75 degrees Celsius. This temperature characteristic matching ensures that the drive mechanism is activated only when the composite switch experiences a significant temperature rise due to load operation, thereby avoiding malfunctions caused by minute environmental temperature differences.

[0026] At one end of chamber 201, a hydraulic cylinder neck is provided, inside which a precision piston 4 is slidably mounted. A high-temperature resistant and wear-resistant combined sealing ring is provided between piston 4 and the inner wall of the chamber to prevent leakage of the phase change medium under high liquid pressure. An axially extending main power rod 3 is fixedly connected to the output end of piston 4. This main power rod 3 extends outward through the end cap of the base, serving as the power output bus for all mechanical subsystems of the entire module. When the heat-sensitive phase change medium in chamber 201 undergoes a phase change from solid to liquid due to heating, its volume expands significantly. The resulting hydrostatic pressure pushes piston 4 outward, thereby driving the main power rod 3 to produce a continuous linear extension displacement.

[0027] To achieve reversible cyclic operation of the mechanism, this embodiment includes a forced reset mechanism along the stroke path of the main force rod 3. Specifically, this reset mechanism employs a high-stiffness helical reset spring 6, which is coaxially sleeved on the rod of the main force rod 3 located outside the phase-change hydraulic drive base 2, or embedded in the non-phase-change region of the chamber 201. One end of the reset spring 6 abuts against the phase-change hydraulic drive base 2, and the other end abuts against the limiting block 5 on the main force rod 3.

[0028] When the composite switch stops working or the load decreases, causing the temperature to drop, the heat-sensitive phase change medium in chamber 201 gradually cools, contracts, and returns to a solid state, reducing its volume and lowering the pressure inside the chamber. At this time, the reset spring 6 releases its pre-stored elastic potential energy, applying a reverse retracting force to the main drive rod 3, forcing the piston 4 to retract and reset until the main drive rod returns to its initial cold position. Through this counterbalancing mechanism of thermal expansion thrust and mechanical elasticity, the phase change hydraulic drive base 2 can convert the temperature fluctuations of the composite switch into usable mechanical reciprocating motion in real time and accurately, providing a stable physical drive source for subsequent heat dissipation, cleaning, and fire extinguishing operations without the need for external power.

[0029] The heat dissipation subsystem includes a ventilation window on the back panel of the enclosure 1. A mechanical louver 7 is embedded and fixedly connected to the ventilation window. A gear 8 is fixedly connected to the opening and closing shaft of the mechanical louver 7. A rack 9 is meshed with the tooth end of the gear 8. The root of the rack 9 is fixedly connected to the outer wall of the drive rod 3. When the drive rod 3 extends, it drives the gear 8 to rotate and causes the blades of the mechanical louver 7 to flip, so that the mechanical louver 7 opens. When the drive rod 3 retracts, it drives the blades of the mechanical louver 7 to flip in the opposite direction, so that the mechanical louver 7 closes.

[0030] Mechanical louvers 7 are located at the ventilation window on the back panel of the cabinet 1, and their height is slightly higher than the composite switch. A gear 8 is fixed on the shaft that controls the opening and closing of the blades of mechanical louvers 7. The gear 8 meshes with a rack 9 fixed on the drive rod 3. When the composite switch experiences a temperature rise due to high load operation, it drives the drive rod 3 to extend outward. The gear 8 and rack 9 work together to convert this linear motion into the opening and closing motion of the blades, driving the blades of mechanical louvers 7 to gradually rotate from the closed state to the open state. As the extension of the drive rod 3 increases, the opening angle of mechanical louvers 7 increases synchronously, thus forming a direct heat dissipation duct to the outside on the back of the cabinet 1. Utilizing the physical property of hot air rising naturally, the open mechanical louvers 7, together with the air inlet at the bottom of the cabinet, form a chimney effect, quickly expelling the hot air gathered around the composite switch outside the cabinet, achieving targeted and efficient heat dissipation.

[0031] The cleaning subsystem includes a dual-spool filter assembly 10, one spool being a take-up spool 1001 and the other a feed spool 1002, connected by a filter 1003. A portion of the filter 1003 is wound around the feed spool 1002. The unfolded filter 1003 covers the air inlet at the bottom of the housing 1, and this portion of the filter 1003 penetrates the housing 1 and covers its outer wall. A damping clip 11 is fixedly connected at this penetration point. The filter screen 1003 passes through and is held by the damping clamp 11. The damping clamp 11 provides damping for the movement of the filter screen 1003 and seals the passage. The end of the take-up reel 1001 is provided with a one-way ratchet mechanism, which is driven by the drive rod 3. When the drive rod 3 extends, the one-way ratchet mechanism is in a meshing transmission state, using the extension stroke to drive the take-up reel 1001 to rotate to refresh the filter screen 1003. When the drive rod 3 retracts, the one-way ratchet mechanism is in a free-slip state. The one-way ratchet mechanism includes a ratchet 12, which is fixedly connected to the end of the take-up reel 1001. A rocker arm 13 is rotatably connected to the center of the ratchet 12. One end of the rocker arm 13 is provided with a pawl 14, and the other end is rotatably connected to an extension rod 15, which is fixedly connected to the drive rod 3.

[0032] To address the issue of dust accumulation at the air inlet during long-term operation and to maintain filter permeability while ensuring heat dissipation, a filter assembly 10 is installed at the air inlet and linked to the drive lever 3 via a one-way ratchet mechanism. After prolonged use, the filter may become clogged, leading to reduced airflow and poor heat dissipation. Upon heating, the drive lever 3 extends, and the one-way ratchet mechanism engages, with the pawl 14 embedding into the tooth groove of the ratchet 12, converting the linear extension motion of the drive lever 3 into the rotational motion of the take-up reel 1001. As the take-up reel 1001 rotates, the dust-laden filter 1003 is rolled up and stored, while the clean filter surface on the feed reel 1002 is pulled out and covers the air inlet. This ensures unobstructed airflow at the air inlet.

[0033] During the retraction of the drive lever 3, the one-way ratchet mechanism is in a slip state. At this time, although the drive lever 3 drives the rocker arm 13 to move, the pawl 14 slides on the back of the ratchet 12 teeth and does not drive the take-up reel 1001 to rotate. This ensures the one-way operation of the filter assembly 10.

[0034] Through the above structure, this invention utilizes the thermal cycle of "heating up and cooling down" each time. This mechanism ensures that after the equipment undergoes one high-temperature operating cycle, the filter media at its air inlet can automatically be renewed or cleaned, maintaining a clean state with low air resistance. This fundamentally solves the technical problem of the heat dissipation efficiency decreasing over time due to filter clogging in traditional distribution boxes. Furthermore, the entire process relies entirely on the physical energy of thermal expansion and contraction, requiring no manual maintenance and consuming no electrical energy.

[0035] The trigger-type fire extinguishing system includes a pressurized fire extinguishing device 16, which is suspended at the top of the housing 1. A spring-loaded firing pin assembly 17 and a stroke-triggered release latch 18 are externally mounted on the trigger end of the device. The spring-loaded firing pin assembly 17 is in a pre-compressed, energy-storing state and is limited by the stroke-triggered release latch 18. The stroke-triggered release latch 18 is fixedly connected to the main force rod 3 via a pull rope 19 with a free stroke. When the extension displacement of the main force rod 3 is within the normal heat dissipation range, the pull rope 19 moves within the free stroke and does not trigger the latch. When the extension displacement of the main force rod 3 exceeds the set extreme high temperature threshold, the main force rod 3 drives the stroke-triggered release latch 18 to release the spring-loaded firing pin assembly 17, causing its firing pin to strike the trigger end of the pressurized fire extinguishing device 16 and release the extinguishing medium.

[0036] The conventional pressurized fire extinguishing device 16 inherently possesses the function of sensing ambient temperature and automatically releasing the extinguishing medium, a function used for the overall fire protection of the distribution box. Building upon this, and taking advantage of the fragile and easily triggered nature of the pressurized fire extinguishing device 16's trigger end, this embodiment additionally incorporates a spring-loaded striker assembly 17 and a stroke-triggered release latch 18 at the trigger end of the pressurized fire extinguishing device 16. A pull rope 19 with a section of idle travel is connected to the main lever 3; this idle travel corresponds to a "safe temperature threshold displacement range" (e.g., 45℃ to 75℃). When the composite switch heats up under normal load or slight overload, and the main lever 3 extends within this range, its displacement is only used to drive the mechanical louvers 7 to open and the filter assembly 10 to clean. The pull rope 19 is not taut, meaning it does not transmit force and will not trigger the stroke-triggered release latch 18. This ensures that the fire extinguishing mechanism will not malfunction due to normal temperature fluctuations in the equipment.

[0037] However, when a serious malfunction occurs in the composite switch (such as severe overheating caused by poor contact, short-circuit arcing, etc.), the medium volume inside the phase-change hydraulic drive base 2 expands dramatically, pushing the main force rod 3 beyond its normal stroke and into the limit displacement zone. At this time, the main force rod 3 eliminates all idle stroke and directly pulls the stroke to trigger the release latch 18. As the mechanical engagement point of the latch disengages, the pre-compressed firing spring instantly releases enormous elastic potential energy, driving the firing pin to strike the trigger end of the pressurized fire extinguishing device 16 at extremely high speed. Once the pressurized fire extinguishing device 16 is triggered, the high-pressure perfluorohexanone or aerosol extinguishing agent inside is sprayed out in a mist-like burst within milliseconds, quickly covering the high-temperature heat source point below. This fire extinguishing method based on pure mechanical thermal displacement triggering is completely independent of the electrical control circuit. Even if the distribution box control system is cut off or malfunctions due to a fire, it can still be forcibly executed by relying on physical laws, converting the extreme displacement of thermal expansion into a trigger signal for fire extinguishing action.

[0038] It should be noted that the trigger temperature of the above-mentioned trigger-type fire extinguishing system is lower than the automatic trigger temperature of the conventional pressurized fire extinguishing device 16 itself. This is because the conventional pressurized fire extinguishing device 16 is designed based on the temperature rise after ignition. However, this embodiment builds a final physical defense line at the critical point where the equipment goes from "overheating" to "ignition", effectively preventing a local fault from evolving into a whole cabinet fire accident.

[0039] The enclosure 1 is also equipped with a displacement monitoring unit and a current transformer, both of which are electrically connected to the data processing unit. The displacement monitoring unit is used to detect the linear displacement of the main force rod 3 in real time, and the current transformer is used to detect the loop current of the composite switch. The data processing unit is configured to perform fault diagnosis based on the following logic: If the loop current is zero or at an unloaded level, and the displacement of the main force rod 3 is continuously greater than the preset safety threshold, it is determined to be non-load-related heating caused by a contact fault or internal short circuit. If the circuit current is at the rated or overload level, and the displacement of the main force rod 3 is significantly lower than the theoretical expansion value, it is determined that the thermal drive mechanism has failed or the phase change medium is leaking.

[0040] This embodiment also provides the logical architecture of a multi-parameter monitoring and diagnostic system based on the displacement of the main force rod 3. While retaining the NTC thermistor array, which is susceptible to electromagnetic interference and can only monitor surface temperature in traditional distribution boxes, an additional indirect monitoring strategy based on mechanical motion feedback is added. For real-time monitoring of faulty composite switches, the core component of the displacement monitoring unit is a high-precision linear displacement sensor or linear potentiometer, installed at the end or side of the main force rod 3 of the phase-change hydraulic drive base 2, and configured to collect real-time linear displacement data of the main force rod 3 relative to the phase-change hydraulic drive base 2. Simultaneously, a current transformer is configured in the control circuit of the distribution box to collect the loop current signal flowing through the composite switch.

[0041] The distribution box is equipped with an independent data processing unit, which receives displacement signals from a linear displacement sensor and current signals from a current transformer. The data processing unit's memory contains pre-set "temperature-volume expansion" characteristic curve data of the heat-sensitive phase change medium, i.e., a mapping model between the displacement of the main force rod 3 and the core temperature inside the composite switch. During equipment operation, the data processing unit does not directly measure the temperature, but instead reads the real-time displacement of the main force rod 3 and uses the mapping model to calculate the degree of heat accumulation inside the composite switch. Because the phase change medium is directly encased inside the heat source, this inversely calculated temperature value more accurately reflects the junction temperature state and heat load level of the power device than the surface temperature measured by the patch sensor.

[0042] Based on the logical correlation between the displacement and current signals described above, the data processing unit in this embodiment is configured to execute a specific fault diagnosis algorithm to distinguish between electrical and mechanical faults. Specifically, when the data processing unit detects that the loop current signal is zero or at an extremely low no-load level, but the displacement amount fed back by the linear displacement sensor continues to exceed a preset safety threshold, the system determines it as "non-load-related abnormal heating." This state typically indicates that there is a severe excessive contact resistance at the terminals of the composite switch, or that the internal thyristor has broken down and short-circuited, resulting in Joule heating sufficient to drive the main lever 3 even without load current. At this time, the system will issue a contact fault alarm.

[0043] Conversely, if the data processing unit detects that the loop current signal remains at the rated value or overload level for an extended period, but the displacement fed back by the linear displacement sensor remains near zero or significantly lower than the theoretical expansion value, the system determines that the "thermal drive mechanism has failed." This state indicates that the phase change medium within the phase change hydraulic drive base 2 may be leaking, or that the connection between the main force rod 3 and other subsystems has become mechanically jammed, preventing thermal energy from being converted into the expected mechanical action. At this time, the system will issue a mechanical fault alarm, prompting maintenance personnel to check the integrity of the phase change hydraulic drive base 2 and the transmission chain.

[0044] In addition, the data processing unit is configured to record the number of times the main drive rod completes a full "extend-retract" cycle. This cumulative count is used as a quantitative indicator to assess the mechanical fatigue life of the composite switch, and also as a reference for determining whether the air inlet filter assembly 10 requires manual deep maintenance or replacement. By unifying all physical state parameters into the mechanical quantity of "displacement" for monitoring, this system greatly simplifies the sensor network and significantly improves the anti-interference capability and robustness of the monitoring system in the complex electromagnetic environment inside the distribution box.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-parameter monitoring low-voltage switchgear based on composite switch control, comprising a cabinet (1), characterized in that, The housing (1) is fixedly connected to a phase change hydraulic drive base (2). The composite switch is installed on the phase change hydraulic drive base (2), and the heat dissipation surface of the composite switch is in contact with the heat conduction surface of the phase change hydraulic drive base (2). The phase change hydraulic drive base (2) is provided with a main power rod (3) extending to its outside. The phase change hydraulic drive base (2) is filled with a heat-sensitive phase change medium for driving the main power rod (3) to move. When the heat-sensitive phase change medium absorbs the heat generated by the composite switch and reaches the phase change temperature, it expands in volume to drive the main power rod (3) to produce an outward linear extension displacement. A reset mechanism is also provided between the main power rod (3) and the phase change hydraulic drive base (2) for driving the main power rod (3) to retract and reset through elastic restoring force when the temperature decreases. The housing (1) is also provided with a heat dissipation subsystem, a cleaning subsystem and a trigger-type fire extinguishing system. All three are driven synchronously by the main power rod (3).

2. The multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 1, characterized in that, The phase change hydraulic drive base (2) has a chamber (201) inside, and a piston (4) is slidably sealed inside the chamber (201). The heat-sensitive phase change medium is filled between the piston (4) and the chamber (201). One end of the active force rod (3) is fixedly connected to the center of the piston (4), and the other end passes through the phase change hydraulic drive base (2). The outer wall of the active force rod (3) is slidably connected to the phase change hydraulic drive base (2).

3. A multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 2, characterized in that, The reset mechanism includes a limiting block (5), which is centrally sleeved and fixedly connected to the outer wall of the active force rod (3). The outer wall of the active force rod (3) is also sleeved with a reset spring (6), which is located between the limiting block (5) and the phase change hydraulic drive base (2), and both ends of the reset spring (6) are fixedly connected to both of them.

4. A multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 1, characterized in that, The heat dissipation subsystem includes a ventilation window on the back panel of the housing (1). A mechanical louver (7) is embedded and fixedly connected to the ventilation window. A gear (8) is fixedly connected to the opening and closing shaft of the mechanical louver (7). A rack (9) is meshed with the tooth end of the gear (8). The root of the rack (9) is fixedly connected to the outer wall of the drive rod (3). When the drive rod (3) extends, it drives the gear (8) to rotate and drives the blades of the mechanical louver (7) to flip, so that the mechanical louver (7) opens. When the drive rod (3) retracts, it drives the blades of the mechanical louver (7) to flip in the opposite direction, so that the mechanical louver (7) closes.

5. A multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 1, characterized in that, The cleaning subsystem includes a filter assembly (10) with a dual-roll structure, one of which is a take-up roll (1001) and the other is a feed roll (1002). The two are connected by a filter (1003), and part of the filter (1003) is wound around the feed roll (1002). The unfolded filter (1003) covers the air inlet at the bottom of the housing (1), and this part of the filter (1003) penetrates the housing (1) and covers the outer wall of the housing (1). A damping clip (11) is fixedly connected at this penetration point. The filter screen (1003) passes through and is held by the damping clamp (11). The damping clamp (11) provides damping for the movement of the filter screen (1003) and seals the passage. The end of the take-up reel (1001) is provided with a one-way ratchet mechanism, which is driven by the drive rod (3). When the drive rod (3) extends, the one-way ratchet mechanism is in the biting transmission state. The extension stroke drives the take-up reel (1001) to rotate to update the filter screen (1003). When the drive rod (3) retracts, the one-way ratchet mechanism is in the idle slip state.

6. A multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 5, characterized in that, The one-way ratchet mechanism includes a ratchet (12), the center of which is fixedly connected to the end of the take-up reel (1001), and a rocker arm (13) is rotatably connected to the center of the ratchet (12). One end of the rocker arm (13) is provided with a pawl (14), and the other end is rotatably connected to an extension rod (15), and the extension rod (15) is fixedly connected to the driving force rod (3).

7. A multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 1, characterized in that, The trigger-type fire extinguishing system includes a pressurized fire extinguishing device (16), which is suspended at the top of the box (1). The trigger end of the device is equipped with a spring-energy-storing striker assembly (17) and a stroke-triggered release lock (18). The spring-energy-storing striker assembly (17) is in a pre-compressed energy-storing state and is limited by the stroke-triggered release lock (18). The stroke-triggered release lock (18) is fixedly connected to the main force rod (3) through a pull rope (19) with a free stroke. When the extension displacement of the main force rod (3) is within the normal heat dissipation range, the pull rope (19) moves within the free stroke and does not trigger the lock. When the extension displacement of the main force rod (3) exceeds the set extreme high temperature threshold, the main force rod (3) drives the stroke-triggered release lock (18) to release the spring-energy-storing striker assembly (17), so that its striker hits the trigger end of the pressurized fire extinguishing device (16) and releases the fire extinguishing medium.

8. A multi-parameter monitoring low-voltage switchgear box based on composite switch control according to claim 1, characterized in that, The housing (1) is also equipped with a displacement monitoring unit and a current transformer, both of which are electrically connected to the data processing unit. The displacement monitoring unit is used to detect the linear displacement of the main force rod (3) in real time, and the current transformer is used to detect the loop current of the composite switch. The data processing unit is configured to perform fault diagnosis based on the following logic: If the loop current is zero or at an unloaded level, and the displacement of the main force rod (3) is continuously greater than the preset safety threshold, it is determined to be non-load-related heating caused by contact fault or internal short circuit. If the circuit current is at the rated or overload level, and the displacement of the main force rod (3) is significantly lower than the theoretical expansion value, it is determined that the thermal drive mechanism has failed or the phase change medium is leaking.

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