CN114078673A

CN114078673A - Controllable full-current-range high-speed breaking excitation fuse module and breaking method thereof

Info

Publication number: CN114078673A
Application number: CN202010809800.3A
Authority: CN
Inventors: 戈西斌; 王欣
Original assignee: Xian Zhongrong Electric Co Ltd
Current assignee: Xian Zhongrong Electric Co Ltd
Priority date: 2020-08-13
Filing date: 2020-08-13
Publication date: 2022-02-22

Abstract

The excitation fuse module comprises a shell and a conductive plate penetrating through the shell, wherein at least three corresponding groups of accommodating cavities are formed in the shell on two sides of the conductive plate at intervals; a piston and an excitation source are sequentially arranged in each accommodating cavity at one side of the conductive plate; the excitation sources are respectively connected with a control panel arranged in the shell; one of the accommodating cavities on the other side of the conductive plate is empty, the bottoms of the other accommodating cavities are respectively provided with an arc extinguishing medium, and a melt body connected with the conductive plate in parallel is arranged in the arc extinguishing medium in a penetrating manner; the breaking current ranges of the melts are different; a weak part is arranged on the conductive plate positioned in the accommodating cavity; when the excitation source drives the piston to move, the piston can break the conductive plate at the weak point of the conductive plate. The invention can realize the quick breaking of the full current and has small volume and light weight.

Description

Controllable full-current-range high-speed breaking excitation fuse module and breaking method thereof

Technical Field

The invention relates to the field of power control and electric automobiles, in particular to an excitation fuse module which is controlled by an external signal and quickly switched off in a full current range and a switching-off method thereof.

Background

The product of circuit overcurrent protection is a fuse which is fused based on heat generated by current flowing through the fuse, and the main problem is the matching relationship between the thermal fuse and a load. For example, in the case of main loop protection of a new energy vehicle, if the load is overloaded by a low multiple or short-circuited, the fuse with the low current specification cannot meet the condition of short-time overshoot of current, and if the fuse with the high current specification is selected, the requirement of rapid protection cannot be met. In the lithium battery pack which provides energy for the current new energy vehicles, the output current is about several times of the rated current under the condition of short circuit, and the protection time of the fuse can not meet the requirement, so that the battery pack generates heat and burns. Because the resistance current heating and the breaking current heating melting are both from the current flowing through the fuse, the protection device adopting the heating melting of the current cannot achieve the breaking speed of the fault current with a certain amplitude value which is fast enough under the condition of having a larger rated current or resisting stronger short-time overload/impact current (such as short-time heavy current when an electric automobile is started or climbs a slope), or achieve a higher rated current under the condition of the protection speed of the fault current with a certain amplitude value which is fast enough, or can resist the larger overload/impact current without damage.

In addition, the thermal fuse has a problem in that it cannot communicate with external devices and cannot be triggered by other signals than current, such as a vehicle ECU, BMS, or other sensors. If the circuit cannot be cut off in time under the conditions of serious collision, water soaking, overhigh temperature of the battery after insolation and the like of the vehicle, the serious event that the vehicle is finally damaged due to the combustion of the battery pack can be caused.

At present, a quick-breaking cut-off opening structure (i.e. an excitation fuse) exists in the market, which mainly comprises a gas generating device, a conductive terminal and a containing cavity after the conductive terminal falls off, wherein the gas generating device generates high-pressure gas to drive a piston to break the conductive terminal, and the conductive terminal falls down into the containing cavity after being broken, so that the purpose of quickly breaking a circuit is achieved. However, it also has some disadvantages and drawbacks, such as insufficient arc extinguishing capability.

Overall, the following disadvantages prevail:

1. a fuse is only suitable for fusing within a certain fault current range, and when the fault current is smaller than the current range, the fuse cannot be fused, the fuse can act only when the fault current reaches more than 3 times of the rated current, and the full-range current disconnection cannot be realized.

2. Under the conditions of large current and large voltage, the overall size of the fuse is correspondingly large, and the application environment with high requirements on size and weight cannot be met.

3. The fuse has poor current impact resistance, the narrow diameter of the melt is narrow, and the fuse cannot bear long-time and repeated large-current impact and is easy to fuse by impact current.

4. If the fuse is used for a long time, the melt may be oxidized or the temperature during operation is high, which may cause the melt characteristics to change.

5. The fuse has large internal resistance generally, and ineffective thermal power loss in normal work is high, heat is large, and temperature is high.

6. The excitation fuse only depending on air arc extinction can not realize effective breaking under the condition of large current such as 10KA, and the excitation fuse only depending on parallel connection fuse body for arc extinction can not realize zero current breaking.

Based on the above disadvantages, the present invention is directed to develop an excitation fuse module capable of satisfying a fast breaking in a full current range, so as to solve some of the disadvantages of the existing thermal fuse and excitation fuse.

Disclosure of Invention

The invention aims to solve the technical problem of providing an excitation fuse module which can meet the requirement of rapid breaking in a full current range and has better electrical performance.

In order to solve the technical problems, the invention provides an excitation fuse module with a controllable full current range and high-speed breaking, which comprises a shell and a conductive plate penetrating through the shell, and is characterized in that at least three groups of accommodating cavities are respectively arranged in the shell at two sides of the conductive plate at intervals, and after the conductive plate is disconnected at the accommodating cavities, the accommodating cavities at two sides of the conductive plate can be communicated; a piston and an excitation source are sequentially arranged in each accommodating cavity at one side of the conductive plate; the excitation sources are respectively connected with a control panel arranged in the shell; one of the accommodating cavities on the other side of the conductive plate is empty, the bottoms of the other accommodating cavities are respectively provided with an arc extinguishing medium, and a melt body connected with the conductive plate in parallel is arranged in the arc extinguishing medium in a penetrating manner; the breaking current ranges of the melts are different; a weak part is arranged on the conductive plate positioned in the accommodating cavity; when the excitation source drives the piston to move, the piston can break the conductive plate at the weak point of the conductive plate.

And a tube shell is arranged in the accommodating cavity, the arc extinguishing medium is arranged in the tube shell, and the melt penetrates through the arc extinguishing medium of the tube shell.

The weak position of the current-conducting plate is provided with a fracture notch penetrating the width of the current-conducting plate.

The fracture notch is a U-shaped groove, a V-shaped groove or a combination of U-shaped grooves and V-shaped grooves which are formed in one surface or two surfaces of the conductive plate.

The invention also provides a breaking method of the controllable full-current-range high-speed breaking excitation fuse module, when the fault current is low and auxiliary arc extinction is not needed during breaking, the control panel controls the action of the excitation source corresponding to the containing cavity without the melt to drive the piston to break the conductive plate at the containing cavity without the melt, and then the control panel controls other excitation sources to act simultaneously to respectively break the conductive plates at the containing cavity with the melt; when the fault current is large and auxiliary arc extinction is needed during breaking, the control panel controls the action of an excitation source corresponding to the containing cavity where the melt containing the fault current in the broken current range is located, and drives the piston to break off the conductive plate at the containing cavity where the melt is located; then the control board controls the action of the excitation source corresponding to the containing cavity without the melt to drive the piston to disconnect the conductive plate at the containing cavity without the melt; and then the control board controls the excitation source corresponding to the accommodating cavity where other melts are located to act to disconnect the conducting plate at the accommodating cavity.

According to the excitation fuse module, the conductive plates are sequentially disconnected through the excitation source, and a plurality of fractures are formed on the conductive plates, so that a circuit is quickly disconnected within a full current range, and even zero current disconnection is realized. Meanwhile, according to the parallel arc extinguishing melt, when the fault current is large, arc extinguishing breaking can be better performed through the arc extinguishing melt. Under normal conditions, the current is almost conducted through the conductive plate, the melt cannot be adversely affected, the conductive plate is disconnected only when the melt needs to be disconnected, and the melt is instantly increased and then quickly fused, so that an auxiliary arc extinguishing effect can be achieved, and the disconnection reliability is ensured; since almost all parts except the conductive plate are injection molded parts, the assembly can be fast. Meanwhile, the piston, the conductive plate, the control plate and other parts can be recycled. Because the injection molding, processing is convenient, and each holding chamber space is arranged, improves space utilization, reduces fuse module volume and weight.

Drawings

FIG. 1 is a schematic longitudinal sectional view of an excitation fuse module according to the present invention.

Fig. 2 is a schematic sectional structure diagram after fault current breaking.

Fig. 3 is a schematic sectional structure diagram after fault current is broken.

Fig. 4 is a schematic sectional structure diagram after fault current is broken.

Fig. 5 is a schematic structural diagram of an arrangement of a plurality of accommodating cavities in which excitation sources are placed.

Detailed Description

The above technical solutions will be specifically described with reference to the drawings by way of examples. The invention discloses an excitation fuse module, which mainly comprises an upper shell, a conductive plate, a lower shell, an excitation source, a control plate, a gland and the like, and is shown in figure 1.

Go up casing 1 and casing 2 constitution excitation fuse module casing down, wear to be equipped with current conducting plate 3 between last casing 1 and casing 2 down. The upper shell 1 and the lower shell 2 are provided with a plurality of corresponding through containing cavities at intervals, and the conducting plate penetrates through the contact surface of the containing cavities of the upper shell and the lower shell. In this embodiment, the number of the accommodating cavities is three, and the accommodating cavities are arranged at intervals in sequence. Two adjacent accommodating cavities of the lower shell are respectively provided with melts (24, 25), and the melts (24, 25) are respectively connected with the conductive plates 3 in parallel. A tube shell 26 is arranged at the bottom of the accommodating cavity, and the melt 24 and the melt 25 are respectively arranged in the tube shell 26 in a penetrating way, and two ends of the tube shell are positioned outside the tube shell. The two ends of the melt 24 and the melt 25 are connected in parallel with the conductive plates respectively along the side walls of the containing cavities upward. An arc-extinguishing medium is arranged in the envelope 26. The bottom of the containing cavity can also be directly provided with an arc extinguishing medium and then sealed by a sealing cover. This kind of fuse element tube shell structure can be according to the holding chamber size in advance, be a simple and easy arc extinguishing fuse with preparation such as tube, fuse-element, when the assembly, places simple and easy arc extinguishing fuse in holding chamber bottom, then be connected the both ends and the current-conducting plate of fuse-element can. The assembly is convenient.

The connection mode of the melt and the conductive plates is that two ends of the melt (24, 25) respectively bend upwards along the side wall of the containing cavity where the melt is located and overlap the upper end surface of the side wall of the containing cavity, and the conductive plates are in pressure joint on the two ends of the melt to realize the parallel connection of the conductive plates and the melt. To ensure the connection is effective, the melt may be connected to the conductive plate by means of conductive glue, welding, or the like. The melt 24 and the melt 25 placed in different accommodating cavities have different specifications according to the size of the fusing current, so that the melt 24 is a large-current melt, the melt 25 is a small-current melt, and the breaking currents of the melt 24 and the melt 25 have overlapped parts. The function of the

melts

24 and 25 is to assist arc extinguishing.

And weak openings which are easy to break are respectively arranged on the conductive plates at each accommodating cavity of the lower shell. In this embodiment, each receiving cavity corresponds to a weak opening (31, 32, 33) in the conductive plate. In order to enable the conductive plates to smoothly fall into the containing cavity below the conductive plates after being disconnected, corresponding rotating notches (34, 35 and 36) are respectively arranged corresponding to each weak opening, so that the conductive plates positioned at each containing cavity can be disconnected from the weak openings under the impact of a piston, and then the conductive plates rotate along circular arc-shaped tracks from the disconnected positions and fall into the containing cavity below the conductive plates along circular arc-shaped tracks. The weak opening and the rotation notch can be arranged on one surface or two surfaces of the conductive plate and penetrate the width of the conductive plate, and the structure of the weak opening and the rotation notch can be U, V or other structures.

The accommodating cavities of the upper shell 1 are respectively provided with an excitation source (11, 12, 13) and a piston (14, 15, 16) from top to bottom in sequence. The excitation sources are respectively fixed on the upper parts of the accommodating cavities, and the fixing mode only needs to be satisfied. The vertical limiting sliding grooves (not shown) penetrating through the contact surface between the upper shell and the lower shell are formed in the cavity wall of each containing cavity respectively, the fixed sliding blocks (not shown) capable of being embedded into the limiting sliding grooves are arranged on the pistons, and the fixed sliding blocks of the pistons are located in the limiting sliding grooves, so that the pistons can be guaranteed to vertically displace along the limiting sliding grooves when being impacted by external force, and the phenomenon of rotation in the containing cavities can be avoided. In order to ensure the initial position of the piston when the piston is not impacted by external force, a limiting device is arranged in the piston and the accommodating cavity in which the piston is arranged. The limiting device can be characterized in that protrusions are arranged on one or two opposite sides of the peripheral wall of the piston, grooves are correspondingly arranged on the wall of the accommodating cavity, and the protrusions on the piston are embedded into the grooves in the wall of the accommodating cavity to realize limiting. The limiting device can be used for opening the limiting device under the action of external force to perform vertical displacement when the piston is impacted by the external force of the excitation source.

The lower end of the piston in each accommodating cavity is over against the weak port on the conductive plate below the piston. When the piston is driven by external force from the exciting source, the weak opening of the conductive plate facing to the lower part can be cut off, so that the broken part of the conductive plate falls into the accommodating cavity of the corresponding lower shell. Go up casing, current conducting plate and lower casing equipment back, each holding chamber in going up the casing, each holding chamber in the casing down each other not communicate each other, when can guaranteeing the piston action in each holding chamber, can not influence each other, can not cause the weak mouth fracture of the current conducting plate of other holding chamber departments.

The upper end surface of the upper shell is covered with a control panel 4 which is a PCB printed circuit board. The excitation sources are respectively connected with the control board 4. The external control system is provided with a current detection device, and can control the corresponding excitation source to act according to the detected current. The control board can be connected with an external control system and receives the excitation signal. In general, the breaking current of the excitation source corresponding to the containing cavity without the parallel melt is minimum, and when the breaking current is small, the arc generated by the excitation source can be extinguished through air or other arc extinguishing media, so that the arc extinguishing of the melt does not need to be assisted in the containing cavity. When the breaking current is large, the corresponding excitation source is triggered to act preferentially according to the breaking current of the parallel melt on the conductive plate.

A cover plate 5 is provided above the control plate 4, and the upper case is sealed by the cover plate 5 while fixing the control plate.

In the above embodiment, the accommodating cavities of the upper housing and the lower housing are arranged at intervals in sequence, and when there are many cavities, the structure may result in a large volume and insufficient compactness of the excitation fuse module. Therefore, the containing chambers of the upper shell and the lower shell can be respectively provided with containing cavities in the four parts A, B, C, D according to the structure of fig. 5, and the containing cavities are arranged in two rows at intervals.

The housing in the above embodiments is divided into an upper housing structure and a lower housing structure, and in specific implementation, the housing may also be divided into a left housing assembly structure and a right housing assembly structure.

In the invention, except the conductive plate, the upper shell, the lower shell, the piston, the cover plate and the like can be injection molded bodies, and the control board is a PCB (printed Circuit Board). The structure is simple to manufacture, light in weight and convenient to assemble.

The working principle of the excitation fuse module is as follows: first, taking the structure of fig. 1 as an example, three pre-breaking openings, namely a weak opening 33, a weak opening 32 and a weak opening 31, are respectively formed in the conductive plate from right to left. The fusant in parallel connection at the weak opening 33 is small fusant and is used for breaking common fault current (such as fault current of 2KA-5 KA); the fusant connected in parallel at the position of the weak opening No. 32 is a large fusant and is used for breaking large fault current (such as fault current above 5KA-12 KA); the weak opening 31 is not connected with the melt in parallel, and is an air fracture opening for arc extinction by air, so that small fault current (such as current below 2 KA) is cut off, and zero current interruption is realized. The control board can control the sequence of the trigger action of the excitation source according to the magnitude of the fault current, and further control the sequence of the break opening of the conductive plate. In a word, when the fault current is large and the arc extinction needs to be assisted during the breaking, the conducting plate connected with the fused mass for arc extinction in parallel is controlled by the control panel to be disconnected firstly, then the conducting plate not connected with the fused mass in parallel is disconnected, and finally the conducting plate connected with the fused mass in parallel is disconnected.

When the excitation fuse module is connected into a circuit, the excitation fuse module is equivalent to a low-resistance conductor when in normal use, such as normal running of an electric automobile, so that the circuit works normally.

When a fault current occurs, the external control system sends a disconnection instruction signal to the control panel 4, the control panel sends a signal to the excitation source in sequence according to a detection current threshold value to trigger the excitation source, a large amount of high-pressure gas is generated in the excitation source to expand downwards, so that 3 pistons are pushed to move downwards in sequence, the conductor is cut off at a plurality of weak positions of the current conducting plate to generate fractures, arcs are rapidly generated at the fractures, the fractures of the parallel connection fusants can be subjected to arc extinction by the fusants, the fractures of the non-parallel connection fusants can be subjected to arc extinction by air, and finally arc extinction and circuit disconnection are achieved. At this point, the fault current is cut off, and the protection of the system circuit is completed.

The method specifically comprises the following steps: when a small fault current (such as a current below 2 KA) occurs, referring to fig. 2, the control board controls the excitation source 11 to trigger, release high-pressure gas to push the piston 14 downward to cut off the conductive plate at the position of the weak port 31 of the conductive plate, the arc is rapidly generated at the fracture, and the generated arc is small due to a small fault current, so that the arc at the fracture is gradually extinguished in the air, and the fault current is successfully cut off. Then, the control board sequentially controls the excitation sources (12, 13) to trigger, the pistons (15, 16) are driven to impact the conductive plates, a plurality of fractures are formed on the conductive plates, and at the moment, the melts (24, 25) are not fused, so that the later die set recovery and waste disposal are facilitated.

When general fault current (such as 2KA-5KA current) occurs, auxiliary arc extinction is needed when the fault current in the range is disconnected. Referring to fig. 3, the control board controls the excitation source 13 to trigger, releases high-pressure gas to push the piston 16 to move downwards to cut off the conductive plate from the weak port 33 of the conductive plate, the fracture generates electric arc rapidly, and the parallel low-current melt is also fused under the high-temperature action generated by the suddenly increased current to perform arc extinction, so that the breaking reliability is ensured; after the control board triggers the excitation source 13, the control board controls the excitation source 11 to trigger to drive the piston 14 to cut off the weak port 31 of the conductive plate to cut off the conductive plate, so as to help form a physical fracture and ensure a cut-off circuit; then the control board controls the excitation source 12 to trigger the action to drive the piston 15 to act to cut off the conductive plate, thereby facilitating the subsequent module recovery and waste disposal.

When a large fault current (such as 5KA-12KA current) occurs, the arc extinction needs to be assisted when the fault current in the range is disconnected. Referring to fig. 4, the control board preferentially controls the excitation source 12 to trigger, releases high-pressure gas to push the piston 15 downwards to move, and cuts off the conductive plate at the position of the weak opening 32 of the conductive plate, the fracture quickly generates electric arc, and the parallel large-current melt and arc extinguishing medium perform arc extinguishing; after the control board triggers the excitation source 12, the control board controls the excitation source 11 to trigger to drive the piston 14 to cut off the weak port 31 of the conductive plate to cut off the conductive plate, so as to help form a physical fracture and ensure a cut-off circuit; then the control board controls the excitation source 13 to trigger the action to drive the piston 16 to act to cut off the conductive plate, thereby facilitating the subsequent module recovery and waste disposal.

Compared with the traditional fuse or the excitation fuse, the excitation fuse module can be suitable for quick breaking in the full current range; and the volume is small, the weight is light, the assembly is convenient, and the recovery is easy.

Claims

1. The excitation fuse module capable of realizing high-speed breaking in a controllable full current range comprises a shell and a conductive plate penetrating through the shell, and is characterized in that at least three groups of accommodating cavities are formed in the shell on two sides of the conductive plate at intervals respectively, and the accommodating cavities on two sides of the conductive plate can be communicated after the conductive plate is disconnected at the accommodating cavities; a piston and an excitation source are sequentially arranged in each accommodating cavity at one side of the conductive plate; the excitation sources are respectively connected with a control panel arranged in the shell; one of the accommodating cavities on the other side of the conductive plate is empty, the bottoms of the other accommodating cavities are respectively provided with an arc extinguishing medium, and a melt body connected with the conductive plate in parallel is arranged in the arc extinguishing medium in a penetrating manner; the breaking current ranges of the melts are different; a weak part is arranged on the conductive plate positioned in the accommodating cavity; when the excitation source drives the piston to move, the piston can break the conductive plate at the weak point of the conductive plate.

2. A controllable full current range high speed breaking excitation fuse module according to claim 1, wherein a tube shell is arranged in the containing cavity, the arc extinguishing medium is arranged in the tube shell, and the melt penetrates through the arc extinguishing medium of the tube shell.

3. A controllable full current range high speed breaking excitation fuse module as claimed in claim 1, wherein said weak point of said conductive plate is a breaking notch formed on said conductive plate and penetrating the width of said conductive plate.

4. A controllable full current range high speed disjunction excitation fuse module set according to claim 1, wherein the fracture notch is a U-shaped, V-shaped or combination of grooves formed on one or both sides of the conductive plate.

5. A controllable full current range high speed disjunction excitation fuse module set according to claim 1, wherein the housing and the piston are both injection molded and integrally formed.

6. A breaking method of an excited fuse module according to claim 1, wherein when the fault current is low and auxiliary arc extinction is not needed, the control board controls the action of the excitation source corresponding to the containing cavity without the melt to drive the piston to break the conductive plate at the containing cavity without the melt; then the control board controls other excitation sources to act simultaneously, and the conductive plates at the accommodating cavities provided with the melt are respectively disconnected; when the fault current is large and auxiliary arc extinction is needed during breaking, the control panel controls the action of an excitation source corresponding to the containing cavity where the melt containing the fault current in the broken current range is located, and drives the piston to disconnect the conducting plate at the containing cavity where the melt is located; then the control board controls the action of the excitation source corresponding to the containing cavity without the melt to drive the piston to disconnect the conductive plate at the containing cavity without the melt; and then the control board controls the excitation source corresponding to the accommodating cavity where other melts are located to act to disconnect the conducting plate at the accommodating cavity.