Low-voltage power supply line overload-preventing branching device

Abstract

The utility model discloses a low -voltage power supply line prevents overload branch device relates to power supply system protection equipment technical field, aims at solving the problem of electromagnetic formula tripping fatigue refusal, electronic formula relies on auxiliary source anti -interference difference lack phase failure, including branch component, prevent overload protection subassembly and arc -extinguishing subassembly, the prevent overload protection subassembly includes the insulation mounting plate and the isolation board of setting in branch component inside, and the isolation board is located the below of insulation mounting plate, the bottom of insulation mounting plate is provided with static contact, the top of isolation board is provided with heating seat, the surface of heating seat is provided with the heating wire, the top of heating seat is provided with shape memory alloy, the top of shape memory alloy is provided with movable contact. The utility model discloses through design branch component and prevent overload protection subassembly, solve traditional electronic formula device to rely on auxiliary power supply, easily suffer voltage fluctuation and electromagnetic interference, and lack phase easy failure's problem, is applicable to complex scene protection.

Description

Technical Field

[0001] This utility model relates to the field of power supply system protection equipment technology, and more specifically, to a low-voltage power supply line overload protection branch device. Background Technology

[0002] In low-voltage power supply systems (such as 220V / 380V), overload protection distribution devices are the core equipment for realizing power distribution and safety protection. They are widely used in residential homes, commercial sites, industrial workshops and construction sites, and must simultaneously meet the dual functions of "power distribution" and "overload fault disconnection".

[0003] Currently, overload protection devices for low-voltage power supply lines are mainly divided into two categories: electromagnetic and electronic. While electromagnetic devices have strong anti-interference capabilities (e.g., less prone to malfunction when high-power equipment starts up on construction sites), they rely on precision mechanical structures, and long-term overload or short-circuit impacts can easily lead to fatigue of the tripping mechanism, resulting in failure to trip or malfunction. Electronic devices, while highly accurate and fast-responding, rely on auxiliary power supplies, and their electronic components are susceptible to voltage fluctuations and electromagnetic interference. For example, in temporary power supply at construction sites, voltage fluctuations may cause electronic devices to misjudge overloads, or even completely fail in the event of a phase loss. Based on these issues, we propose an overload protection device for low-voltage power supply lines. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the existing technology, adapt to the needs of reality, and provide a low-voltage power supply line overload protection branch device to solve the problems of electromagnetic tripping failure due to fatigue and electronic auxiliary power source interference poor phase loss failure.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a low-voltage power supply line overload protection branching device, including a branching assembly, an overload protection assembly, and an arc extinguishing assembly; the overload protection assembly includes an insulating mounting plate and an isolation plate disposed inside the branching assembly, with the isolation plate located below the insulating mounting plate; a stationary contact is disposed at the bottom of the insulating mounting plate; a heating seat is disposed at the top of the isolation plate; a heating wire is disposed on the surface of the heating seat; a shape memory alloy is disposed at the top of the heating seat; and a moving contact is disposed at the top of the shape memory alloy; the arc extinguishing assembly includes an arc extinguishing cavity disposed on the rear surface of the branching assembly; an arc ignition port is disposed on one side of the arc extinguishing cavity and extends into the interior of the branching assembly; neodymium iron boron permanent magnets are disposed on both sides inside the arc extinguishing cavity; arc extinguishing grids are uniformly disposed in the middle of the interior of the arc extinguishing cavity; arc-splitting elements are disposed between the arc-splitting grids; and a melamine plate is disposed on the surface of the arc-splitting elements; The shape memory alloy is C-shaped. When the current is overloaded, the heating base and heating wire heat the shape memory alloy to the austenitic phase, generating recovery strain, triggering the moving contact to move quickly and separate rapidly from the stationary contact. At the same time, the middle part of the shape memory alloy extends into the arc inlet.

[0006] Preferably, the branching assembly includes a distribution box, the distribution box having a main busbar mechanism and a branching mechanism respectively inside, the bottom of the branching mechanism having a fuse-type disconnect switch, the top of the distribution box having a main line inlet, and the bottom of the distribution box having a branching outlet.

[0007] Preferably, the arc-extinguishing grid plate has a V-shaped notch on the side near the arc initiation port. The notches of the arc-extinguishing grid plate are connected to form an arc-extinguishing groove, which guides the arc to move along a specific path and enter the arc-extinguishing zone. The notches of adjacent arc-extinguishing grid plates are staggered to form a maze-like channel.

[0008] Preferably, the opposite surfaces of the neodymium iron boron permanent magnet are arranged in an arc shape, forming a gradient magnetic field with the arc initiation port, causing the electric arc to move rapidly towards the arc extinguishing cavity under the action of the Lorentz force.

[0009] Preferably, an accelerometer and a fiber Bragg grating sensor are installed inside the arc-extinguishing cavity.

[0010] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model, through the design of branching components and overload protection components, heats the shape memory alloy to the austenitic phase when the current is overloaded, generating recovery strain and triggering the moving contact to act quickly and separate rapidly from the stationary contact. A C-shaped NiTi shape memory alloy is used instead, which has a stable phase change response, and the C-shaped structure can disperse short-circuit impact stress, avoiding component damage. This solves the problems of traditional electronic devices relying on auxiliary power, being susceptible to voltage fluctuations and electromagnetic interference, and easily failing due to phase loss. The heating wire of this device draws power directly from the main circuit, eliminating the need for an auxiliary power supply and avoiding protection gaps caused by power failure. The core protection relies on the mechanical response of the shape memory alloy, without complex electronic units, resulting in a zero false trip rate under electromagnetic interference, and voltage fluctuations do not affect the protection logic. In the event of a phase loss, the corresponding branch does not trigger a false trip, and the normal phase can still be overload protected, making it suitable for protection in complex scenarios.

[0011] 2. This utility model also designs an arc-extinguishing component. When the shape memory alloy generates recovery strain, the middle part of the shape memory alloy extends into the arc-starting port. The arc-shaped neodymium iron boron permanent magnet, together with the arc-starting port, forms a gradient magnetic field, causing the arc to move rapidly towards the arc-extinguishing cavity under the action of the Lorentz force, avoiding the arc from being stuck in the moving contact. By setting V-shaped notches on the surface of the arc-extinguishing grid, the notches of the arc-extinguishing grid are connected to form an arc-extinguishing groove, guiding the arc to move along a specific path and enter the arc-extinguishing zone. The notches of adjacent arc-extinguishing grids are staggered to form a labyrinthine channel, dividing the arc into short arcs. Each segment has insufficient voltage to maintain discharge, achieving initial arc extinguishing. The melamine board decomposes the inert gas at high temperature to achieve final arc extinguishing, avoiding contact erosion and secondary circuit faults, and ensuring safety and stability after disconnection. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the branching component structure of this utility model; Figure 3 This is a schematic diagram of the overload protection component of this utility model; Figure 4 This is a schematic diagram of the arc-extinguishing component structure of this utility model; Figure 5 This is a schematic diagram of the internal structure of the arc-extinguishing cavity of this utility model; Figure 6 This is a schematic diagram of the arc-splitting component structure of this utility model; Figure 7 This is a schematic diagram of the connection structure between the overload protection component and the arc extinguishing component of this utility model.

[0013] The following are the labels in the diagram: 1. Distribution assembly; 101. Distribution box; 102. Main busbar mechanism; 103. Distribution mechanism; 104. Fuse-type disconnect switch; 2. Overload protection assembly; 201. Insulating mounting plate; 202. Stationary contact; 203. Isolation plate; 204. Heating base; 205. Heating wire; 206. Shape memory alloy; 207. Moving contact; 3. Arc extinguishing assembly; 301. Arc extinguishing cavity; 302. Arc ignition port; 303. Neodymium iron boron permanent magnet; 304. Arc extinguishing grid; 305. Arc splitting component; 306. Melamine board. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments: This utility model relates to an overload protection branching device for low-voltage power supply lines, comprising a branching assembly 1, an overload protection assembly 2, and an arc-extinguishing assembly 3. The overload protection assembly 2 includes an insulating mounting plate 201 and an isolation plate 203 fixedly connected inside the branching assembly 1, with the isolation plate 203 located below the insulating mounting plate 201. A stationary contact 202 is fixedly connected to the bottom of the insulating mounting plate 201, and a heating base 204 is fixedly connected to the top of the isolation plate 203. A heating wire 205 is wound around the surface of the heating base 204, and a shape memory alloy 206 is fixedly connected to the top of the heating base 204. A moving contact 207 is fixedly connected to the top of the shape memory alloy 206. The insulating mounting plate 201 is used for insulation and isolation and for fixing the stationary contact 202. To prevent conductive interference between the stationary contact 202 and other components, the isolation plate 203 is used for insulation and to support the heating base 204, preventing the heating base 204 from forming a conductive path with the structure below. The stationary contact 202 and the moving contact 207 cooperate to form the fixed end of the conductive path. Under normal conditions, the stationary contact 202 contacts the moving contact 207 to conduct current. The heating base 204 fixes and supports the heating wire 205, ensuring that the heat from the heating wire 205 is stably transferred to the shape memory alloy 206. The heating wire 205 is heated by the circuit current. When the current is overloaded, sufficient heat is generated to trigger the phase transformation of the shape memory alloy 206. The shape memory alloy 206 maintains a C-shape at room temperature, allowing the moving contact 207 to contact the stationary contact 202. Under overload, it is heated to the austenite phase, generating recovery strain, and the C-shape... The shape memory alloy 206 unfolds, triggering the separation of the moving contact 207 from the stationary contact 202, cutting off the circuit. The moving contact 207 and the stationary contact 202 cooperate to form the active end of the conductive path, driven by the shape memory alloy 206 to separate and engage with the stationary contact 202, completing the circuit switching. The arc extinguishing assembly 3 includes an arc extinguishing cavity 301 fixedly connected to the rear surface of the branch assembly 1. An arc ignition port 302 is fixedly connected to one side of the arc extinguishing cavity 301, and the arc ignition port 302 extends into the interior of the branch assembly 1. Neodymium iron boron permanent magnets 303 are fixedly connected to both sides inside the arc extinguishing cavity 301. Arc extinguishing grid plates 304 are uniformly fixedly connected in the middle inside the arc extinguishing cavity 301. Arc-splitting components 305 are fixedly connected between the arc extinguishing grid plates 304. Trimeric alloy is fixedly connected to the surface of the arc-splitting components 305. The melamine plate 306 and the arc-extinguishing chamber 301 form a closed space to contain the arc extinguishing process and prevent the arc from leaking out and damaging other components. The arc initiation port 302 guides the arc generated by the contact separation into the arc-extinguishing chamber 301 to ensure that the arc is effectively handled. The neodymium iron boron permanent magnet 303 generates a magnetic field, causing the arc to move towards the arc-extinguishing grid plate 304 under the action of the Lorentz force, accelerating the arc migration. The arc-extinguishing grid plate 304 divides the long arc into multiple short arc segments. Taking advantage of the fact that the voltage of the short arc is insufficient to maintain the discharge, the arc is extinguished faster. The arc-splitting component 305 assists in dividing the arc, increases the contact area between the arc and the arc-extinguishing grid plate 304, and enhances the arc extinguishing effect. The melamine plate 306 decomposes at the high temperature of the arc to produce inert gas, forming a gas blowing effect to accelerate the cooling of the arc and suppress the arc reignition.This invention, through the design of a branching assembly 1 and an overload protection assembly 2, allows the heating base 204 and heating wire 205 to heat the shape memory alloy 206 to the austenitic phase when the current is overloaded. This generates recovery strain, triggering the moving contact 207 to act quickly and separate rapidly from the stationary contact 202. A C-shaped NiTi shape memory alloy 206 is used instead, offering stable phase change response. Furthermore, the C-shaped structure disperses short-circuit impact stress, preventing component damage and solving the problems of traditional electronic devices relying on auxiliary power, being susceptible to voltage fluctuations and electromagnetic interference, and prone to failure in the event of a phase loss. The heating wire 205 in this device draws power directly from the main circuit, eliminating the need for an auxiliary power supply and avoiding protection gaps caused by power failure. The core protection relies on the mechanical response of the shape memory alloy 206, without complex electronic units, resulting in a zero false trip rate under electromagnetic interference. Voltage fluctuations do not affect the protection logic. In the event of a phase loss, the corresponding branch does not trigger a false trip and operates normally. The phase can still be overload protected, suitable for protection in complex scenarios; this utility model also designs an arc extinguishing component 3, when the shape memory alloy 206 generates recovery strain, the middle part of the shape memory alloy 206 extends into the arc ignition port 302, the arc-shaped neodymium iron boron permanent magnet 303 cooperates with the arc ignition port 302 to form a gradient magnetic field, so that the arc moves quickly towards the arc extinguishing cavity 301 under the action of Lorentz force, avoiding the arc from being stuck in the moving contact 207; by setting a V-shaped notch on the surface of the arc extinguishing grid plate 304, the notches of the arc extinguishing grid plate 304 are connected to form an arc extinguishing groove, guiding the arc to move along a specific path and enter the arc extinguishing zone. The notches of adjacent arc extinguishing grid plates 304 are staggered to form a labyrinth channel, dividing the arc into short arcs. Each segment has insufficient voltage to maintain discharge, achieving initial arc extinguishing; the melamine board 306 decomposes inert gas at high temperature to achieve final arc extinguishing, avoiding contact erosion and secondary faults in the circuit, ensuring safety and stability after disconnection.

[0015] Specifically, the branch assembly 1 includes a distribution box 101. The distribution box 101 has a main busbar mechanism 102 and a branch mechanism 103 fixedly connected inside. A fuse-type disconnect switch 104 is fixedly connected to the bottom of the branch mechanism 103. The top of the distribution box 101 has a main line inlet, and the bottom has a branch line outlet. The distribution box 101 serves as the outer shell of the branch assembly 1, providing protection and integrating all internal components. The main busbar mechanism 102 carries the main line current and is the main conductor distributing electrical energy to each branch. The branch mechanism 103 distributes the main busbar current to each branch, realizing branched power transmission. The fuse-type disconnect switch 104 provides circuit isolation and short-circuit protection in the branch, forming dual protection with the overload protection assembly 2. The main line inlet provides an interface for the main power supply line access device, facilitating connection between the main line and the main busbar. The branch line outlet provides an interface for the load line lead-out device of each branch, facilitating connection between the branch and the branch mechanism 103.

[0016] More specifically, the arc-extinguishing grid 304 has a V-shaped notch on the side near the arc initiation port 302. The notches of the arc-extinguishing grid 304 are connected to form an arc-extinguishing groove, which guides the arc to move along a specific path and enter the arc-extinguishing zone. The notches of adjacent arc-extinguishing grids 304 are staggered to form a labyrinthine channel. The V-shaped notch forms an arc-extinguishing groove, which guides the arc to move along a specific path. The staggered arrangement of adjacent notches forms a labyrinthine channel, which increases the arc path length and the contact area with the grid, thereby enhancing the arc segmentation and cooling effect.

[0017] It is worth mentioning that the opposite surfaces of the neodymium iron boron permanent magnet 303 are arranged in an arc shape, forming a gradient magnetic field with the arc initiation port 302. This causes the electric arc to move rapidly toward the arc extinguishing cavity 301 under the action of the Lorentz force, thereby enhancing the Lorentz force on the electric arc and accelerating the movement of the electric arc toward the arc extinguishing grid plate 304.

[0018] It is worth noting that an accelerometer and a fiber Bragg grating sensor are installed inside the arc extinguishing cavity 301. The accelerometer and fiber Bragg grating sensor are used to detect the deformation of the arc extinguishing grating 304, provide early warning of grating wear or failure, and ensure the reliability of the arc extinguishing assembly 3.

[0019] Working principle: This embodiment provides a low-voltage power supply line overload protection branch device. In use, the heating wire 205 heats up rapidly as the current increases, causing the shape memory alloy 206 to reach the phase change temperature. The C-shaped structure unfolds, triggering the separation of the moving contact 207 and the stationary contact 202, cutting off the branch current. The arc generated by the contact separation enters the arc initiation port 302 under the guidance of the shape memory alloy 206. Under the action of the Lorentz force of the neodymium iron boron permanent magnet 303, it moves towards the arc extinguishing grid plate 304. The arc is divided into multiple short arcs by the arc splitting component 305, achieving initial arc extinguishing. The melamine plate 306 decomposes upon heating, generating gas to accelerate cooling, achieving final arc extinguishing.

[0020] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of this utility model based on the above embodiments and make different extensions and variations. However, as long as they do not depart from the spirit of this utility model, they are all within the protection scope of this utility model.

Claims

1. A low-voltage power supply line overload protection branch device, characterized in that, The assembly includes a branching assembly (1), an overload protection assembly (2), and an arc extinguishing assembly (3). The overload protection assembly (2) includes an insulating mounting plate (201) and an isolation plate (203) disposed inside the branching assembly (1), with the isolation plate (203) located below the insulating mounting plate (201). A stationary contact (202) is disposed at the bottom of the insulating mounting plate (201), and a heating base (204) is disposed at the top of the isolation plate (203). A heating wire (205) is disposed on the surface of the heating base (204), and a shape memory alloy (206) is disposed at the top of the heating base (204). (206) has a moving contact (207) at its top; the arc extinguishing assembly (3) includes an arc extinguishing cavity (301) disposed on the rear surface of the branch assembly (1), an arc initiation port (302) is disposed on one side of the arc extinguishing cavity (301), and the arc initiation port (302) extends into the interior of the branch assembly (1), neodymium iron boron permanent magnets (303) are disposed on both sides of the interior of the arc extinguishing cavity (301), an arc extinguishing grid plate (304) is uniformly disposed in the middle of the interior of the arc extinguishing cavity (301), an arc splitting component (305) is disposed between the arc extinguishing grid plates (304), and a melamine plate (306) is disposed on the surface of the arc splitting component (305); The shape memory alloy (206) is C-shaped. When the current is overloaded, the heating seat (204) and the heating wire (205) heat the shape memory alloy (206) to the austenitic phase, generating recovery strain, triggering the moving contact (207) to move quickly and separate rapidly from the stationary contact (202). At the same time, the middle part of the shape memory alloy (206) extends into the arc inlet (302).

2. The low-voltage power supply line overload protection branch device according to claim 1, characterized in that, The branch assembly (1) includes a distribution box (101), inside which a main busbar mechanism (102) and a branch mechanism (103) are respectively provided. A fuse-type disconnect switch (104) is provided at the bottom of the branch mechanism (103). A main line inlet is provided at the top of the distribution box (101), and a branch line outlet is provided at the bottom of the distribution box (101).

3. The low-voltage power supply line overload protection branch device according to claim 2, characterized in that, The arc-extinguishing grid plate (304) has a V-shaped notch on the side near the arc initiation port (302). The notches of the arc-extinguishing grid plate (304) are connected to form an arc-extinguishing groove, which guides the arc to move along a specific path and enter the arc-extinguishing zone. The notches of adjacent arc-extinguishing grid plates (304) are staggered to form a maze-like channel.

4. The low-voltage power supply line overload protection branch device according to claim 3, characterized in that, The opposite surfaces of the neodymium iron boron permanent magnet (303) are arranged in an arc shape, forming a gradient magnetic field with the arc initiation port (302), causing the electric arc to move rapidly towards the arc extinguishing cavity (301) under the action of Lorentz force.

5. The low-voltage power supply line overload protection branch device according to claim 4, characterized in that, The arc-extinguishing cavity (301) is equipped with an accelerometer and a fiber Bragg grating sensor.

Images