A circuit protection device integrated with a passive-active integrated excitation structure

Abstract

A circuit protection device integrating an active-passive integrated excitation structure includes a housing and conductive terminals. The active-passive integrated excitation structure is connected in series between two conductive terminals. An arc-extinguishing medium or auxiliary arc-extinguishing device is disposed between the active-passive integrated excitation structure and the housing. The active-passive integrated excitation structure includes a sealed excitation housing, a conductive busbar, a signal fuse, an excitation source, and a piston. The pre-break points of the excitation source, piston, and conductive busbar are respectively located in the excitation housing, with the piston corresponding to the pre-break point. The signal fuse is connected in series with the conductive busbar, and the signal receiving end of the excitation source is conductively connected to both ends of the signal fuse to form a self-excited triggering circuit. The excitation source can receive trigger signals sent from the self-excited triggering circuit and activate. The circuit protection device features reliable trigger signals, fast response speed, and relatively low temperature rise under low overload current, ensuring the structural integrity of the housing.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical switches, and in particular to circuit protection devices that integrate an active and passive excitation structure. Background Technology

[0002] With the rapid development of the photovoltaic energy storage industry and the increasing demands under various complex environments and operating conditions, photovoltaics, as an important component of the energy storage industry, has more specific requirements for circuit protection due to its special application environment: wider protection range, greater current carrying capacity, and higher intelligence requirements.

[0003] Currently, fuses are the main type of fuse used for circuit protection. Fuse products are mainly divided into two categories: traditional fuses and activated fuses. Traditional fuses consist of a casing, an arc-extinguishing medium, and a fusible element. The arc-extinguishing medium is filled in the casing, and the fusible element is inserted within it. During a fault current, the fusible element heats up to its melting point and melts, thus providing circuit protection. A drawback of traditional fuses is that at low overload currents, the temperature rises very slowly, and the fusible element takes a long time to melt, failing to meet the requirement of rapid circuit disconnection under low overload conditions. Activated fuses consist of an excitation source, a piston, and a conductor bus. The excitation source receives an external trigger signal and releases high-pressure gas as a driving force to move the piston. The kinetic energy generated by the piston's displacement breaks the conductor bus, thereby disconnecting the circuit and providing circuit protection. Activated fuses mechanically disconnect the conductor bus, offering a fast response time; however, a reliable trigger signal cannot be guaranteed. The active-passive integrated excitation fuse connects a signal fuse element in series on a conductor busbar. The signal receiving end of the excitation source is connected to an external active triggering circuit, and simultaneously connected in parallel to both ends of the signal fuse element to form a self-excited triggering circuit. When the trigger signal sent by the external active triggering circuit is unreliable, the voltage signal generated when the signal fuse element melts during a fault current can be used as the trigger signal for the excitation source, passively triggering its operation. The active-passive integrated excitation fuse solves the problem of unreliable excitation source trigger signals. However, it also has drawbacks: because the fuse housing is generally made of plastic, under low overload currents, the signal fuse element may only melt after prolonged current flow, causing the temperature at the signal fuse element to rise extremely high. This can overwhelm the plastic housing, causing it to soften or even partially melt at high temperatures, reducing housing strength and lowering product safety performance. Summary of the Invention

[0004] The purpose of this invention is to fill the space between the outer periphery of the active-passive integrated excitation structure and the outer shell with an arc-extinguishing medium, so that the signal melt and part of the conductive busbar are also located in the arc-extinguishing medium. The high temperature generated on the signal melt when the low overload current is directly borne by the arc-extinguishing medium, thereby reducing the temperature of the outer shell, achieving shell protection, and improving product safety performance.

[0005] To achieve the above objectives, the present invention provides a circuit protection device integrating an active-passive integrated excitation structure, comprising a housing, both ends of which are respectively sealed by end caps, the end caps serving as conductive terminals or having conductive terminals disposed on the end caps; an active-passive integrated excitation structure is connected in series between the two conductive terminals, the active-passive integrated excitation structure being located within the housing; an arc-extinguishing medium or auxiliary arc-extinguishing device is disposed between the active-passive integrated excitation structure and the housing; the active-passive integrated excitation structure includes a sealed excitation housing, a conductive busbar, a signal fuse, an excitation source, and a piston; the excitation source, piston, and pre-break of the conductive busbar are respectively located within the excitation housing, the piston being disposed corresponding to the pre-break; the signal fuse is connected in series with the conductive busbar, and the signal receiving end of the excitation source is conductively connected to both ends of the signal fuse to form a self-excited triggering circuit, the excitation source being able to receive and activate a trigger signal sent from the self-excited triggering circuit.

[0006] Preferably, the signal receiving end of the excitation source can also receive trigger signals from the outside.

[0007] Preferably, the signal melt is located in the arc-extinguishing medium between the excitation housing and the outer shell, and the conductive terminal is connected in series with the signal melt and the conductive busbar.

[0008] Preferably, the conductive bus portions located on opposite sides of the excitation housing are bent in the opposite direction along the excitation housing and have a gap with the outer peripheral surface of the excitation housing.

[0009] Preferably, the excitation housing includes a first housing and a second housing fixedly connected, the conductive busbar is disposed between the first housing and the second housing, and the piston and the excitation source are disposed in the first housing; the portion of the conductive busbar located outside the excitation housing is bent in the opposite direction, one end of which passes over the second housing and is conductively connected to the signal melt, and the other end passes over the first housing and is conductively connected to the conductive terminal closest to the excitation source; when the excitation source is activated to release high-pressure gas, it drives the piston to displace and disconnect the pre-break point within the excitation housing.

[0010] Preferably, the signal melt is provided with a narrow neck, which divides the signal melt portion on both sides of the conductor bus into two asymmetrical parts along the length of the conductor bus. The signal melt portion on the side of the narrow neck closer to the excitation source is longer.

[0011] Preferably, the outer shell has a tubular structure.

[0012] Preferably, the outer shell is made of ceramic.

[0013] Preferably, the excitation housing and the piston are both high-temperature resistant plastic structures.

[0014] Preferably, a connecting conductor is provided inside the housing near the end cap, the conductive terminal passes through the end cap and is electrically connected to the connecting conductor, and the connecting conductor is electrically connected to the signal fuse and the conductive busbar respectively.

[0015] Preferably, an arc-extinguishing melt is connected in parallel on the conductive busbar, the arc-extinguishing melt being located between the outer shell and the excitation shell, or within the excitation shell; the arc-extinguishing melt is connected in parallel with the pre-break and in series with the signal melt.

[0016] Preferably, an arc-extinguishing chamber is provided in the excitation housing, and an arc-extinguishing medium is provided in the arc-extinguishing chamber. When the arc-extinguishing melt is located in the excitation housing, the arc-extinguishing melt passes through the arc-extinguishing chamber.

[0017] Preferably, the active-passive integrated excitation structure is a modular structure.

[0018] Preferably, the auxiliary arc-extinguishing device is a metal wire mesh or an arc-extinguishing grid.

[0019] This invention combines an active-passive integrated excitation structure with the appearance structure of a traditional fuse. An arc-extinguishing medium is filled between the high-temperature resistant outer shell and the excitation shell of the traditional fuse. The excitation shell is reinforced by the outer shell and the arc-extinguishing medium. At the same time, the heat energy of the conductor is transferred to the outer shell through the arc-extinguishing medium, and the heat energy is dissipated to the outside through the high-temperature resistant ceramic shell. This reduces the material requirements of the excitation shell and simplifies the assembly process.

[0020] The signal melt, the conductive busbar located outside the excitation housing, and the arc-extinguishing melt are all located in the arc-extinguishing medium. The arc-extinguishing medium directly withstands the increased temperature of the signal melt and reduces the arc temperature to extinguish the arc. At the same time, due to the presence of the arc-extinguishing medium, and the fact that the piston, excitation housing, and outer shell are all made of high-temperature resistant materials, and the asymmetrical design of the narrow neck of the signal melt, it is ensured that the piston, excitation housing, and outer shell will not soften during the entire operation, thus ensuring the reliability of the circuit protection device and the integrity of the overall structure.

[0021] Under low current conditions, the signal fuse melts quickly. Due to the small current, it is difficult for an arc to sustain at the break point formed by the signal fuse. In other words, the signal fuse melts, completely disconnecting the main circuit. The main circuit is protected by the fast operating time of a traditional fuse. However, under high current short-circuit conditions, the signal fuse melts, generating a larger arc. This can easily lead to a brief arc sustaining at the break point. In this case, the main circuit is not completely disconnected. When a passive trigger signal is sent to the excitation source via a self-excited triggering circuit, the excitation source activates, cutting off the main circuit via a piston, thus protecting the entire circuit. This invention also offers better current-carrying capacity compared to traditional fuses. Therefore, this invention combines the high-temperature resistance (ceramic housing) of traditional fuses with an asymmetrical structure of the signal fuse, achieving better fast breaking capacity and current-carrying capacity for small currents compared to similar traditional fuses. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structural principle.

[0023] Figure 2 This is a schematic diagram of the signal melt structure.

[0024] Figure 3 This is a schematic diagram of the excitation housing and the conductor bus structure.

[0025] Figure label:

[0026] Conductive terminals (101, 107), first conductor 102, arc-extinguishing fusible element 103, conductive busbar 104, housing 105, excitation source 106, signal fusible element 108, arc-extinguishing medium 109, piston 110, wire 112, second conductor 113, excitation housing 115, first housing 116, second housing 117, pre-break 118, neck 119. Detailed Implementation

[0027] The circuit protection device of the present invention, which integrates an active-passive excitation structure, includes a housing, with both ends of the housing sealed by end caps, the end caps serving as conductive terminals or having conductive terminals disposed on the end caps; an active-passive excitation structure is connected in series between the two conductive terminals and is located within the housing; an arc-extinguishing medium is disposed between the active-passive excitation structure and the housing; the active-passive excitation structure includes a sealed excitation housing, a conductive busbar, a signal fuse, an excitation source, and a piston; the pre-break points of the excitation source, piston, and conductive busbar are respectively located within the excitation housing, with the piston corresponding to the pre-break point; the signal fuse is connected in series with the conductive busbar, and the signal receiving end of the excitation source is electrically connected to both ends of the signal fuse to form a self-excited triggering circuit, the excitation source being able to receive and activate a trigger signal sent from the self-excited triggering circuit.

[0028] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solution of this invention.

[0029] A circuit protection device combining an active / passive integrated excitation structure with a fuse, see [link / reference]. Figures 1 to 3 The system includes a high-temperature resistant housing 105, which is a tubular structure. Both ends of the housing 105 are sealed by end caps. The housing 105 can be made of a high-temperature resistant material such as ceramic. Conductive terminals (101, 107) are respectively provided at both ends of the housing 105. The conductive terminals (101, 107) pass through the end caps and are electrically connected to a first conductor 102 and a second conductor 113 located inside the housing 105. In some embodiments, the end caps can also be used directly as conductive terminals. The first conductor 102 and the second conductor 113 are located inside the end caps. An integrated active-passive excitation structure is connected in series between the first conductor 102 and the second conductor 113 inside the housing 105. The integrated active-passive excitation structure is located inside the housing 105, and an arc-extinguishing medium is filled between the housing 105 and the integrated active-passive excitation structure.

[0030] The active-passive integrated excitation structure includes an excitation housing 115, a signal melt 108, a conductive bus 104, a piston 110, and an excitation source 106. The excitation housing 115, as shown in Figure 3, includes a high-temperature resistant first housing 116 and a second housing 117. The first housing 116 and the second housing 117 are joined together, and the conductive bus 104 passes between the joint surfaces of the first housing 116 and the second housing 117. The first housing 116 and the second housing 117 are fixedly connected by bolts to form the excitation housing 115, thus fixing the conductive bus 104 between the first housing 116 and the second housing 117.

[0031] The conductive busbar 104 located outside the first housing 116 and the second housing 117 is bent in opposite directions on the outside of the excitation housing. A certain gap is maintained between the bent conductive busbar and the outer surface of the excitation housing. One end of the conductive busbar extends beyond the second housing 117 towards the first conductor 102 and is electrically connected to the signal fuse 108 located on one side of the first conductor 102. The other end of the conductive busbar extends beyond the first housing 116 and is electrically connected to the second conductor 113. The other end of the signal fuse 108 is electrically connected to the first conductor 102, thus connecting the conductive busbar 104 and the signal fuse 108 in series. The two ends of the series-connected conductive busbar 104 and signal fuse 108 are respectively connected in series to the first conductor 102 and the second conductor 113. The conductive busbar 104 located inside the excitation housing 115 is provided with a pre-break 118. The mechanical strength at the pre-break 118 is relatively low to facilitate the disconnection of the conductive busbar 104 from the pre-break 118. A piston 110 and an excitation source 106 are sequentially arranged in the first housing 116. The excitation source 106 is a gas generating device that can release high-pressure gas as a driving force according to a trigger signal. The excitation source 106 seals one end of the cavity of the first housing 116 away from the second housing 117, forming a sealed cavity within the excitation housing. The piston 110 is disposed in the cavity of the first housing 116. The impact head of the piston 110 is positioned corresponding to the pre-break 118 of the conductive busbar 104. The high-pressure gas release end of the excitation source 106 is positioned corresponding to the piston 110. The signal receiving end of the excitation source 106 is located outside the first housing 116. The signal receiving end of the excitation source 106 is electrically connected to both ends of the signal fuse 108 via wires 112 to form a self-excited triggering circuit, thus connecting the excitation source 106 in parallel with the circuit formed by the series-connected signal fuse and conductive busbar. The excitation source 106 can also be electrically connected to an external trigger circuit outside the circuit protection device. Under normal operating conditions, the signal fuse 108 is on, and the self-excited trigger circuit is off. When a fault current occurs, the signal fuse 108 melts, creating a brief arc. A high voltage is generated at the point where the signal fuse 108 is broken, causing the self-excited trigger circuit to conduct. This sends a trigger signal to the excitation source 106, causing it to actuate and release high-pressure gas to drive the piston 110 to displace, disconnecting it from the pre-break point 118 of the conductor bus 104. The self-excited trigger circuit's conduction is controlled by a voltage-controlled switch-like component.

[0032] An arc-extinguishing medium 109 or an auxiliary arc-extinguishing device is provided between the excitation housing and the outer shell 105. The signal melt 108, the conductive busbar located outside the excitation housing, and the wire 112 are all located outside the excitation housing and within the arc-extinguishing medium 109. The arc generated when the signal melt 108 melts is extinguished by the arc-extinguishing medium 109 or the auxiliary arc-extinguishing device. The arc-extinguishing medium 109 can be a gaseous arc-extinguishing medium, such as an inert gas, or a solid arc-extinguishing medium, such as quartz sand. The auxiliary arc-extinguishing device is an arc-extinguishing structure that can extinguish arcs, such as a metal wire mesh or an arc-extinguishing grid.

[0033] Signal melt 108, see Figure 2 The signal fuse 108 is provided with a narrow neck 119. Along the reverse direction of the current, the narrow neck 119 divides the signal fuse into two asymmetrical parts; that is, the distances of the narrow neck 119 from the two ends of the signal fuse in the current direction are different. By setting the position of the narrow neck, uneven heat dissipation is formed on both sides of the fuse during current carrying, achieving the purpose of directional heat dissipation and directional heat insulation. Preferably, the signal fuse portion near the excitation source on the narrow neck is longer, so most of the heat energy is dissipated through the longer side, dispersing the heat energy inside the casing. During the operation of the circuit protection device, under high-temperature conditions, the inside of the casing remains safe and reliable, without softening, and the signal fuse can still be effectively triggered. Moreover, the casing is made of high-temperature resistant ceramic material, so the heat dissipation of the signal fuse will not affect the casing. The signal fuse 108 is located away from the inner wall of the casing 105. To achieve this, the two ends of the signal fuse 108 are electrically connected to the conductive bus and the first conductor via conductors.

[0034] An arc-extinguishing melt 103 is connected in parallel to a conductive busbar 104 outside the excitation housing. Both ends of the arc-extinguishing melt 103 are electrically connected to the conductive busbar 104 on both sides of the pre-break and located outside the excitation housing, forming an arc-extinguishing melt 103 connected in parallel with the pre-break 118. The resistance of the arc-extinguishing melt 103 is greater than the resistance of the conductive busbar 104. During normal current flow, current flows through the conductive busbar 104 and the signal melt 108.

[0035] The first housing, second housing, outer shell, and piston in the excitation housing are made of high-temperature resistant materials, such as high-temperature resistant plastic, and are all integrally molded by injection molding.

[0036] The integrated active and passive excitation structure can be modular, meaning it is first prefabricated and assembled into a modular structure, and then the integrated active and passive excitation structure is assembled and connected with the housing, conductive terminals, etc. This simplifies the number of parts, simplifies the assembly process, and improves assembly efficiency.

[0037] Working principle:

[0038] During normal operation, the current flows through the circuit formed by the conductive terminals, conductive busbar, signal fuse, and conductive terminals connected in series, and the self-excited trigger circuit is not conductive.

[0039] When a fault current occurs, the signal fuse melts and forms an arc at the break point of the signal fuse, which activates the self-excitation trigger circuit and sends a trigger signal to the excitation source 106. The excitation source 106 then releases high-pressure gas, driving the piston 110 to move and disconnect the conductive bus 104 from the pre-break point 118 inside the excitation housing. After the conductive bus 104 is disconnected, the current flows through the break point between the arc-extinguishing fuse 103 and the signal fuse, causing the arc-extinguishing fuse 103 to melt.

[0040] During the entire process, the signal melt 108 melts and the generated arc is extinguished by the arc-extinguishing medium. Because the arc-extinguishing medium participates in the arc extinguishing at the signal melt, the arc holding time at the break point of the signal melt is shortened, and the continuous high temperature time after the signal melt melts is shortened.

[0041] Since the conductive busbar 104 is disconnected from the pre-break point 118, most of the current flows through the arc-extinguishing melt 103 when it is disconnected. Therefore, the electric arc generated when the conductive busbar 104 is disconnected is small, the temperature rise inside the excitation housing is relatively low, and the piston inside the displacement excitation housing will not soften due to high temperature.

[0042] In the above embodiments, the arc-extinguishing melt is located outside the excitation housing. In some embodiments, the arc-extinguishing melt can be located inside the excitation housing. When the arc-extinguishing melt is located inside the excitation housing, an arc-extinguishing chamber filled with an arc-extinguishing medium is provided inside the excitation housing. The arc-extinguishing melt passes through the arc-extinguishing medium, and both ends of the arc-extinguishing melt are electrically connected to the conductive busbar portions at both ends of the conductive busbar pre-break, so that the arc-extinguishing melt is connected in parallel to the conductive busbar, forming a parallel relationship with the conductive busbar pre-break. When the arc-extinguishing melt is located inside the excitation housing, a displacement channel corresponding to the piston can also be provided inside the excitation housing. The arc-extinguishing melt passes through the displacement channel, and the melt cutting component is provided in the displacement channel. When the piston displaces and disconnects the conductive busbar, it can drive the melt cutting component to displace and cut off the arc-extinguishing melt.

[0043] In some embodiments, an arc-extinguishing medium or an auxiliary arc-extinguishing device is provided in the excitation housing.

[0044] In all the above embodiments, regardless of how the arc-extinguishing medium or auxiliary arc-extinguishing device is set, the principle is to ensure that it does not affect the melting of the signal melt, piston displacement, disconnection of the conductive busbar, or melting of the arc-extinguishing melt. Especially when displacement actions such as piston displacement or disconnection of the conductive busbar are involved, the arc-extinguishing medium must be designed to allow for such displacement. The arc-extinguishing medium can be a gaseous arc-extinguishing medium, such as an inert gas, or a solid arc-extinguishing medium, such as quartz sand. The auxiliary arc-extinguishing device is an arc-extinguishing structure capable of extinguishing arcs, such as a metal wire mesh or an arc-extinguishing grid.

Claims

1. A circuit protection device integrated with a passive-active integrated excitation structure, characterized in that, The device includes a housing, with both ends of the housing sealed by end caps, the end caps serving as conductive terminals or having conductive terminals disposed on the end caps; an integrated active-passive excitation structure is connected in series between the two conductive terminals, the integrated active-passive excitation structure being located within the housing; An arc-extinguishing medium or auxiliary arc-extinguishing device is provided between the active and passive integrated excitation structure and the outer shell; The active-passive integrated excitation structure includes a sealed excitation housing, a conductive busbar, a signal melt, an excitation source, and a piston. The excitation source, piston, and pre-break points of the conductive busbar are respectively located in the excitation housing, and the piston is positioned corresponding to the pre-break points. The signal melt is connected in series with the conductive busbar, and the signal receiving end of the excitation source is electrically connected to both ends of the signal melt to form a self-excited triggering circuit. The excitation source can receive trigger signals sent from the self-excited triggering circuit to activate.

2. The circuit protection device of claim 1, wherein, The signal receiving end of the excitation source can also receive trigger signals from the outside.

3. The circuit protection device of claim 1, wherein, The signal melt is located in the arc-extinguishing medium between the excitation housing and the outer shell, and the conductive terminal is connected in series with the signal melt and the conductive busbar.

4. The circuit protection device of claim 3, wherein, The conductive busbar portions located on opposite sides of the excitation housing are bent in the opposite direction along the excitation housing and have a gap with the outer peripheral surface of the excitation housing.

5. The circuit protection device of claim 4, wherein, The excitation housing includes a first housing and a second housing that are fixedly connected, the conductive bus is disposed between the first housing and the second housing, and the piston and the excitation source are disposed in the first housing; After the conductive busbar portion located outside the excitation housing is bent in the opposite direction, one end passes over the second housing and is electrically connected to the signal melt, and the other end passes over the first housing and is electrically connected to the conductive terminal closest to the excitation source; When the excitation source releases high-pressure gas, it drives the piston to move and disconnect the pre-break within the excitation housing.

6. The circuit protection device of claim 1, wherein, The signal melt is provided with a narrow neck. Along the length of the conductor bus, the narrow neck divides the signal melt portion located on both sides of it into two asymmetrical parts, with the signal melt portion on the side of the narrow neck closer to the excitation source being longer.

7. The circuit protection device of claim 1, wherein, The outer shell has a tubular structure.

8. The circuit protection device of claim 1, wherein, The outer shell is made of ceramic.

9. The circuit protection device of claim 1, wherein, The excitation housing and the piston are both made of high-temperature resistant plastic structures.

10. The circuit protection device of claim 1, wherein, Inside the housing, near the end cap, there are connecting conductors. The conductive terminal passes through the end cap and is electrically connected to the connecting conductors. The connecting conductors are electrically connected to the signal fuse and the busbar, respectively.

11. The circuit protection device of claim 1, wherein, An arc-extinguishing melt is connected in parallel to the conductive busbar. The arc-extinguishing melt is located between the outer shell and the excitation shell, or in the excitation shell. The arc-extinguishing melt is connected in parallel with the pre-break and in series with the signal melt.

12. The circuit protection device of claim 11, wherein, An arc-extinguishing chamber is provided in the excitation housing, and an arc-extinguishing medium is filled in the arc-extinguishing chamber. When the arc-extinguishing melt is located in the excitation housing, the arc-extinguishing melt passes through the arc-extinguishing chamber.

13. The circuit protection device of claim 1, wherein, The active-passive integrated excitation structure is a modular structure.

14. The circuit protection device of claim 1, wherein, The auxiliary arc-extinguishing device is a metal wire mesh or an arc-extinguishing grid.

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