Electric circuit breaker device

Abstract

An electric circuit breaker device (60) is a device for driving a current breaker (20) having control terminals (23a, 23b) and provided on a current path (11). The electric circuit breaker device (60) comprises: a control circuit (40) for outputting a cutoff signal for causing the current breaker (20) to transition from a conductive state to a non-conductive state on the basis of a detection signal output from a current detection unit (50) that detects a current flowing through the current path (11); and an insulating circuit (30) that is provided on a path connecting the control circuit (40) and the control terminals (23a, 23b) of the current breaker (20), transmits the cutoff signal output from the control circuit (40) to the control terminals (23a, 23b) of the current breaker (20), and electrically insulates the control circuit (40) and the control terminals (23a, 23b) of the current breaker (20) from each other. When the current breaker (20) has transitioned from the conductive state to the non-conductive state, the control circuit (40) and the control terminals (23a, 23b) of the current breaker (20) are electrically insulated from each other by the insulating circuit (30).

Description

Electrical Circuit Breaker

[0001] The present disclosure relates to an electric circuit interruption device, and more particularly to an electric circuit interruption device that has a control terminal and drives a current interrupter provided on a current path.

[0002] In the electrical circuits of automobiles, etc., electrical circuit interruption devices are used to prevent serious damage by interrupting the electrical circuit (i.e., interrupting the current) in the event of an abnormality such as a short circuit in the load. As an electrical circuit interruption device, technology has been proposed for a current interrupter such as a pyrofuse that houses an igniter, a projectile (piston), a bus bar, etc. in a housing (see Patent Document 1).

[0003] JP 2019-53911 A

[0004] In the technology of Patent Document 1, when the current from the high-voltage source is cut off, an arc generated in the cut bus bar may cause high voltage to flow into the control terminal of the igniter, potentially destroying the control circuit connected to the control terminal of the igniter.

[0005] An electrical circuit interruption device according to one embodiment of the present disclosure is an electrical circuit interruption device that drives a current interrupter that has a control terminal and is arranged on a current path, and includes: a control circuit that outputs an interruption signal to transition the current interrupter from a conductive state to a non-conductive state based on a detection signal output from a current detection unit that detects the current flowing through the current path; and an isolation circuit that is arranged on the path connecting the control circuit and the control terminal of the current interrupter, transmits the interruption signal output from the control circuit to the control terminal of the current interrupter, and electrically isolates the control circuit from the control terminal of the current interrupter, and when the current interrupter transitions from a conductive state to a non-conductive state, the control circuit and the control terminal of the current interrupter are electrically isolated by the isolation circuit.

[0006] The present disclosure provides an electrical circuit breaker that can prevent a control circuit from being destroyed by a sneak high voltage.

[0007] Fig. 1 is a circuit diagram showing the configuration of an electric circuit interruption device according to an embodiment. Fig. 2 is a flowchart showing operation in a diagnostic mode by the electric circuit interruption device according to the embodiment. Fig. 3 is a flowchart showing operation in a interruption mode by the electric circuit interruption device according to the embodiment. Fig. 4 is a diagram showing interruption operation of a current breaker provided in the electric circuit interruption device according to the embodiment. Fig. 5 is a diagram showing a modified example of an insulation circuit provided in the electric circuit interruption device according to the embodiment. Fig. 6 is a flowchart showing operation in an interruption mode by the electric circuit interruption device according to a second modified example. Fig. 7 is a flowchart showing operation in a diagnostic mode by the electric circuit interruption device according to a third modified example. Fig. 8 is a flowchart showing operation in an interruption mode by the electric circuit interruption device according to the third modified example. Fig. 9 is a diagram showing modified examples of switch elements included in the insulation circuits provided in the electric circuit interruption devices according to the embodiment and the modified examples.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each embodiment described below represents a specific example of the present disclosure. The numerical values, shapes, materials, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, each figure is not necessarily an exact illustration. In each figure, substantially identical configurations are assigned the same reference numerals, and redundant explanations are omitted or simplified. Furthermore, "A and B are connected" means that A and B are electrically connected, and includes not only the case where A and B are directly connected, but also the case where A and B are indirectly connected with another circuit element interposed between A and B.

[0009] FIG. 1 is a circuit diagram showing the configuration of an electric circuit interruption device 60 according to an embodiment. The electric circuit interruption device 60 is a device that drives a current interrupter 20, and in this embodiment, includes the current interrupter 20, a current detection unit 50, an insulation circuit 30, and a control circuit 40. In addition to the electric circuit interruption device 60, this diagram also shows a power source 10, a current path 11, and a load 12. The current interruption device 20 is shown in a schematic cross-sectional view. Furthermore, the current interruption device 20 and the current detection unit 50 do not necessarily have to be components of the electric circuit interruption device 60. In other words, the electric circuit interruption device 60 may include only the insulation circuit 30 and the control circuit 40.

[0010] The power supply 10 is a current source that supplies current to a load 12 via a current path 11, and is, for example, a high-voltage (for example, about 400 V) battery mounted on an EV (electric vehicle).

[0011] The load 12 is a load for the current supplied from the power supply 10, and is, for example, an inverter mounted on an EV.

[0012] The current breaker 20 is an active circuit breaker that is provided on the current path 11, has control terminals 23 a and 23 b, and breaks the current flowing through the current path 11 when a break signal (specifically, a drive current) that satisfies a predetermined condition is input to the control terminals 23 a and 23 b. In the present embodiment, the current breaker 20 is, for example, a pyrotechnic circuit breaker (a pyrotechnic circuit breaker, an irreversible pyrotechnic circuit breaker), and includes a housing 21 including a cylinder 21 a, control terminals 23 a and 23 b exposed from the housing 21, an igniter 22 that burns (i.e., ignites) a built-in explosive when a drive current equal to or greater than a predetermined value is applied to the control terminals 23 a and 23 b, a projectile 24 that flies downward from within the cylinder 21 a by the thrust obtained by the combustion of the igniter 22, and a bus bar 25 that is configured by connecting conductor pieces 25 a and 25 c at both ends connected to the current path 11 and a central cutting portion 25 b that is cut by the projectile 24 that has gained the thrust. Furthermore, a pyro-fuse can instantaneously interrupt a large current in the event of an abnormality more quickly than a blown fuse, so if power source 10 is a large-capacity, high-voltage battery mounted on an EV (electric vehicle), it is more preferable that current breaker 20 according to the embodiment be a pyro-fuse.

[0013] The current detection unit 50 is a sensor that detects the current flowing through the current path 11, and is, for example, a shunt-type current sensor (a conductor piece with a low resistance, a shunt resistor). Note that the current detection unit 50 can use other types (for example, a current sensor using a Hall element) in addition to a shunt resistor (shunt type). However, in terms of ease of installation in the electrical circuit breaker 60, it is more preferable to use a shunt resistor (shunt type), which can be made smaller than a current sensor using a Hall element.

[0014] The isolation circuit 30 is provided on the path connecting the control circuit 40 and the control terminals 23a and 23b of the current breaker 20, and transmits the interruption signal output from the control circuit 40 to the control terminals 23a and 23b of the current breaker 20, and electrically isolates the control circuit 40 from the control terminals 23a and 23b of the current breaker 20 until the current breaker 20 transitions from a conductive state to a non-conductive state.

[0015] In other words, the isolation circuit 30 is provided on a path connecting the control circuit 40 and the control terminals 23a and 23b of the current breaker 20, and is a circuit that transmits the interruption signal output from the control circuit 40 to the control terminals 23a and 23b of the current breaker 20. When the current breaker 20 transitions from a conductive state to a non-conductive state, the isolation circuit 30 electrically isolates the control circuit 40 from the control terminals 23a and 23b of the current breaker 20.

[0016] More specifically, in this embodiment, the isolation circuit 30 includes an isolation transformer 31 including a primary winding 31a connected to the control circuit 40 and a secondary winding 31b connected to the control terminals 23a and 23b of the current breaker 20, and switch elements 32a and 32b inserted in a path connecting the primary winding 31a and the secondary winding 31b. The isolation transformer 31 is, for example, a pulse transformer. The switch elements 32a and 32b are elements that selectively enter a conductive state or a non-conductive state based on a control signal output from the control circuit 40 (more specifically, the controller 42), and are, for example, FETs or photo-MOS relays. Note that FIG. 1 omits the connection between the switch elements 32a and 32b and the control circuit 40 (more specifically, the controller 42).

[0017] The control circuit 40 has the functions of outputting a control signal for controlling the switch elements 32a and 32b of the isolation circuit 30 to the switch elements 32a and 32b, applying a minute constant current for diagnostic purposes (i.e., a diagnostic signal) to the control terminals 23a and 23b of the current circuit breaker 20 via the switch elements 32a and 32b of the isolation circuit 30, and outputting a blocking drive current (i.e., a blocking signal) for transitioning the current circuit breaker 20 from a conductive state to a non-conductive state to the control terminals 23a and 23b of the current circuit breaker 20 via the isolation transformer 31 of the isolation circuit 30 based on a detection signal output from a current detection unit 50 that detects the current flowing through the current path 11. The control circuit 40 is composed of an amplifier 41, a controller 42, and a drive circuit 43.

[0018] The amplifier 41 is an amplifier, for example, a voltage amplifier circuit, that amplifies a signal corresponding to the current detected by the current detection unit 50 (here, a minute voltage corresponding to the voltage drop in the current detection unit 50) and outputs it to the controller 42.

[0019] The controller 42 has a blocking mode in which the current breaker 20 is controlled to perform a blocking operation based on the signal output from the amplifier 41 (i.e., the voltage corresponding to the current detected by the current detection unit 50), and a diagnostic mode in which the controller 42 diagnoses whether the current breaker 20 is normal or not via the insulation circuit 30, and is composed of a microcomputer having, for example, a memory for storing programs, a timer, input / output ports, a processor for executing programs, etc.

[0020] The drive circuit 43 is a circuit that outputs a pulse current (i.e., a shutdown signal) to drive the primary winding 31 a of the isolation transformer 31 to ignite the igniter 22 based on a shutdown control signal for the shutdown mode output from the controller 42, and applies a predetermined small constant current (i.e., a diagnostic signal) to the control terminals 23 a and 23 b of the current breaker 20 via the switch elements 32 a and 32 b of the isolation circuit 30 based on a diagnostic control signal for the diagnostic mode output from the controller 42 to measure the resistance value between the control terminals 23 a and 23 b. In this embodiment, the drive circuit 43 is composed of two transistors 43 a and 43 b connected in series to the primary winding 31 a. Note that, in this embodiment, the drive circuit 43 is composed of two bipolar transistors (transistors 43 a and 43 b). However, the configuration is not limited to this and may be composed of, for example, two FETs or only one of the two transistors (the other is short-circuited).

[0021] Furthermore, the isolation circuit 30 and the control circuit 40 may be mounted on a single circuit board, or may be mounted on separate circuit boards.

[0022] Next, the operation of the electrical circuit breaker 60 according to this embodiment configured as described above will be described.

[0023] 2 is a flowchart showing the operation of the diagnostic mode by the electrical circuit interruption device 60 according to the embodiment. The diagnostic mode may be started at any timing other than the interruption mode, for example, when a control signal for starting the diagnostic mode is input from the outside to the controller 42, or may be started at regular time intervals.

[0024] In the diagnostic mode, first, the controller 42 of the control circuit 40 outputs control signals to the switch elements 32a and 32b to turn the switch elements 32a and 32b on (S10). In this embodiment, the switch elements 32a and 32b are normally on and are turned off only when the interruption mode is executed, so step S10 is executed only initially, such as when the electrical circuit interruption device 60 is activated. In other words, if the switch elements 32a and 32b are already on, step S10 is skipped.

[0025] Next, the controller 42 outputs a diagnostic control signal to the drive circuit 43 (i.e., applies current to the base terminals of the transistors 43a and 43b), thereby controlling the flow of a minute constant current for diagnostic purposes (i.e., a diagnostic signal) through a current path that runs from the current output terminal of the drive circuit 43 (strictly speaking, the emitter terminal of the transistor 43a) through the switch element 32a of the isolation circuit 30, the control terminal 23a of the current breaker 20, the control terminal 23b of the current breaker 20, and the switch element 32b of the isolation circuit 30 to the current input terminal of the drive circuit 43 (strictly speaking, the collector terminal of the transistor 43b) (S11).

[0026] Then, the controller 42 detects a voltage drop occurring between the control terminals 23a and 23b of the current breaker 20 when such a predetermined minute constant current is applied, thereby determining whether the resistance value between the control terminals 23a and 23b of the current breaker 20 is within a normal range, and thereby diagnosing whether the current breaker 20 is in a normal state (i.e., a state in which the igniter 22 can operate) (S12). The voltage drop occurring between the control terminals 23a and 23b of the current breaker 20 is detected, for example, by measuring the voltage between the emitter terminal of the transistor 43a and the collector terminal of the transistor 43b in the drive circuit 43.

[0027] By operating in this diagnostic mode, it is determined whether the current breaker 20 is in a normal state in which it can perform a breaking operation.

[0028] FIG. 3 is a flowchart showing the operation in the interruption mode by the electrical circuit interruption device 60 according to the embodiment.

[0029] First, the controller 42 of the control circuit 40 determines whether or not a predetermined current (e.g., a current corresponding to when the load 12 is short-circuited) has been detected by the current detection unit 50 based on the signal output from the amplifier 41 (S20).

[0030] As a result, if the predetermined current is not detected (No in S20), the controller 42 repeats detection of the predetermined current, but if the predetermined current is detected (Yes in S20), the controller 42 controls the switch elements 32a and 32b to transition from a conductive state to a non-conductive state (S21), and then outputs a cutoff control signal to the drive circuit 43 so that a cutoff drive current (i.e., a cutoff signal) necessary to ignite the igniter 22 is applied to the control terminals 23a and 23b of the current breaker 20 via the drive circuit 43 and the isolation circuit 30 (more specifically, the isolation transformer 31) (S22). Note that steps S21 and S22 may be executed simultaneously.

[0031] As a result, as shown in Fig. 4, in current breaker 20, igniter 22 is ignited, and projectile 24, propelled by the combustion of the gunpowder, flies downward from within cylinder 21a, colliding with cutting portion 25b of bus bar 25 and separating cutting portion 25b from bus bar 25, thereby cutting bus bar 25. Fig. 4 is a diagram showing the interruption operation of current breaker 20 provided in electrical circuit interruption device 60 according to the embodiment. Fig. 4(a) shows a schematic cross-sectional view of current breaker 20 before the interruption operation, and Fig. 4(b) shows a schematic cross-sectional view of current breaker 20 after the interruption operation.

[0032] Here, even if, during an interruption by such a current breaker 20, an arc occurs within the current breaker 20 due to the cutting of the bus bar 25 and a high voltage flows into the control terminals 23a and 23b, in the isolation circuit 30 connected to the control terminals 23a and 23b, the switch elements 32a and 32b are already in a non-conductive state and the control terminals 23a and 23b and the control circuit 40 are insulated by the isolation transformer 31, so that the high voltage is prevented from flowing into the control circuit 40 and destroying it.

[0033] 3, after the current detection unit 50 detects a predetermined current (Yes in S20), the controller 42 controls the switch elements 32a and 32b to be in a non-conductive state (S21), but this procedure is not limited thereto, and the controller 42 may control the switch elements 32a and 32b to be in a non-conductive state before (i.e., in advance of) the current detection unit 50 detects a predetermined current. In other words, the control to keep the switch elements 32a and 32b in a non-conductive state (S21) may be performed at any timing as long as it is performed before the current breaker 20 is caused to perform a break operation (S22).

[0034] In addition, in the present embodiment, the switch elements 32a and 32b are brought into a non-conductive state by the controller 42, but this is not limited to the controller 42. For example, the switch elements 32a and 32b may be brought into a non-conductive state by a dedicated circuit that issues a control signal when a predetermined current is detected by the current detection unit 50.

[0035] 5 is a diagram showing a modified example of the insulation circuit 30 provided in the electrical circuit interruption device 60 according to the embodiment. That is, this diagram shows examples of various insulation circuits that can be substituted for the insulation circuit 30 according to the embodiment.

[0036] More specifically, FIG. 5A shows an isolation circuit 30a according to a first modification. The isolation circuit 30a corresponds to the isolation circuit 30 according to the embodiment, which includes only the isolation transformer 31 (i.e., does not include the switch elements 32a and 32b). When the electrical circuit interruption device 60 includes the isolation circuit 30a according to this modification instead of the isolation circuit 30, the electrical circuit interruption device according to the first modification does not include the switch elements 32a and 32b and therefore does not have a diagnostic mode. On the other hand, in the interruption mode, the electrical circuit interruption device according to the first modification includes the isolation circuit 30a including the isolation transformer 31, so steps S20 and S22 in the flowchart shown in FIG. 3 are executed (i.e., step S21 is not executed). As a result, in the interruption mode, the current interrupter 20 performs an interruption operation when the current detection unit 50 detects a predetermined current, and high voltage leakage to the control circuit 40 is suppressed, as in the embodiment.

[0037] 5B shows an isolation circuit 30b according to a second modification. The isolation circuit 30b corresponds to a configuration including only the switch elements 32a and 32b in the isolation circuit 30 according to the embodiment (i.e., not including the isolation transformer 31). When the electrical circuit interruption device 60 includes the isolation circuit 30b according to this modification instead of the isolation circuit 30, the electrical circuit interruption device according to the second modification includes the switch elements 32a and 32b, and therefore has a diagnostic mode similar to the embodiment, and executes the diagnostic mode in accordance with the procedure shown in the flowchart of FIG. 2.

[0038] On the other hand, in the interruption mode, the electrical circuit interruption device according to the second modification executes the interruption mode by controlling the switch elements 32a and 32b according to the procedure shown in the flowchart of FIG. 6 . FIG. 6 is a flowchart illustrating the operation of the electrical circuit interruption device according to the second modification in the interruption mode. Assume that the switch elements 32a and 32b are in their normal, i.e., conductive, states. First, the controller 42 of the control circuit 40 determines whether a predetermined current has been detected by the current detection unit 50 based on the signal output from the amplifier 41 (S20). If the predetermined current has been detected (Yes in S20), the controller 42 outputs an interruption control signal to the drive circuit 43 so that a drive current (i.e., an interruption signal) required to ignite the igniter 22 is applied to the control terminals 23a and 23b of the current interrupter 20 via the drive circuit 43 and the isolation circuit 30b (more specifically, the switch elements 32a and 32b) (S22). These steps S20 and S22 are similar to those shown in FIG. 3 . Thereafter, promptly (i.e., within a predetermined short time, such as within 0.5 msec from step S22, after ignition of the igniter 22 in the current breaker 20 until the bus bar 25 is cut off) the controller 42 controls the switch elements 32a and 32b to transition from the conductive state to the non-conductive state (S30). As a result, even if a high voltage flows into the control terminals 23a and 23b when the current breaker 20 breaks, the control terminals 23a and 23b of the current breaker 20 and the control circuit 40 are insulated by the switch elements 32a and 32b, and therefore, the high voltage is prevented from flowing into the control circuit 40 and damaging the control circuit 40.

[0039] Referring again to Fig. 5, Fig. 5(c) shows an isolation circuit 30c according to a third modification. The isolation circuit 30c corresponds to a configuration in which the switch elements 32a and 32b in the isolation circuit 30 according to the embodiment are replaced with fuses 33a and 33b, and the isolation transformer 31 is not included. When the electrical circuit interruption device 60 includes the isolation circuit 30c according to this modification instead of the isolation circuit 30, the electrical circuit interruption device according to the third modification has the fuses 33a and 33b and therefore has a diagnostic mode. Fig. 7 is a flowchart showing the operation of the diagnostic mode by the electrical circuit interruption device according to the third modification. First, the controller 42 outputs a diagnostic control signal to the drive circuit 43 (i.e., applies current to the base terminals of the transistors 43a and 43b), thereby controlling the flow of a predetermined minute constant current (i.e., a diagnostic signal) in a range that will not melt the fuses 33a and 33b through a current path that runs from the current output terminal of the drive circuit 43 (strictly speaking, the emitter terminal of the transistor 43a) through the fuse 33a of the isolation circuit 30c, the control terminal 23a of the current breaker 20, the control terminal 23b of the current breaker 20, and the fuse 33b of the isolation circuit 30c to the current input terminal of the drive circuit 43 (strictly speaking, the collector terminal of the transistor 43b) (S40). Then, the controller 42 detects the voltage drop that occurs between the control terminals 23a and 23b of the current breaker 20 when such a predetermined small constant current is applied, thereby determining whether the resistance value between the control terminals 23a and 23b of the current breaker 20 is within a normal range, and thereby diagnosing whether the current breaker 20 is in a normal state (i.e., a state in which the igniter 22 can operate) (S41).

[0040] On the other hand, in the interruption mode, the electric circuit interruption device according to the third modification executes the interruption mode by performing the control shown in the flowchart of Fig. 8. Fig. 8 is a flowchart showing the operation of the electric circuit interruption device according to the third modification in the interruption mode. First, the controller 42 of the control circuit 40 determines whether a predetermined current has been detected by the current detection unit 50 based on the signal output from the amplifier 41 (S20). If the predetermined current has been detected (Yes in S20), the controller 42 outputs an interruption control signal to the drive circuit 43 so that the fuses 33a and 33b melt before the bus bar 25 is cut after a drive current (i.e., an interruption signal) required to ignite the igniter 22 is applied to the control terminals 23a and 23b of the current interrupter 20 via the drive circuit 43 and the insulation circuit 30c (more specifically, the fuses 33a and 33b) (S50). More specifically, the controller 42 ignites the igniter 22 and then outputs a cutoff control signal to the drive circuit 43 so that the drive circuit 43 outputs a pulse current of a predetermined magnitude and a predetermined duration required to melt the fuses 33a and 33b within the time until the bus bar 25 is cut (for example, within 0.5 msec).

[0041] As a result, even if a high voltage flows into the control terminals 23a and 23b when the current breaker 20 is interrupted, the control terminals 23a and 23b of the current breaker 20 and the control circuit 40 are insulated by the melting of the fuses 33a and 33b, thereby preventing the high voltage from flowing into the control circuit 40 and destroying it.

[0042] 9 is a diagram showing a modification of the switch elements 32a and 32b included in the isolation circuits of the electrical circuit breakers according to the above-described embodiments and modifications. As shown in this figure, the switch element 32a (32b) in the above-described embodiments and modifications may be replaced with a series connection of multiple switch elements 32a1 and 32a2 (32b1 and 32b2) with lower voltage resistance. This can reduce the manufacturing cost of the isolation circuit.

[0043] As described above, the electrical circuit interruption device 60 according to the embodiment and the modified example is a device that has control terminals 23a and 23b and drives a current interrupter 20 that is provided on the current path 11, and includes a control circuit 40 that outputs an interruption signal to transition the current interrupter 20 from a conductive state to a non-conductive state based on a detection signal output from a current detection unit 50 that detects the current flowing through the current path 11, and an isolation circuit 30 that is provided on the path connecting the control circuit 40 and the control terminals 23a and 23b of the current interrupter 20, transmits the interruption signal output from the control circuit 40 to the control terminals 23a and 23b of the current interrupter 20, and electrically isolates the control circuit 40 from the control terminals 23a and 23b of the current interrupter 20 at least until the current interrupter 20 transitions from a conductive state to a non-conductive state.

[0044] As a result, an isolation circuit 30 or the like is provided on the path connecting the control circuit 40 and the control terminals 23a and 23b of the current breaker 20, and the isolation circuit 30 or the like transmits the interruption signal output from the control circuit 40 to the control terminals 23a and 23b of the current breaker 20, and electrically isolates the control circuit 40 from the control terminals 23a and 23b of the current breaker 20 at least until the current breaker 20 transitions from the conductive state to the non-conductive state. Therefore, even if a high voltage flows into the control terminals 23a and 23b of the current breaker 20 due to an arc generated when the current breaker 20 breaks, the high voltage is prevented from flowing into the electrically isolated control circuit, and destruction of the control circuit is prevented.

[0045] Here, the isolation circuit 30 etc. may include an isolation transformer 31 having a primary winding 31a connected to the control circuit 40 and a secondary winding 31b connected to the control terminals 23a and 23b of the current breaker 20. This allows the interruption signal output from the control circuit 40 to be transmitted to the control terminals 23a and 23b of the current breaker 20, and electrically isolates the control circuit 40 from the control terminals 23a and 23b of the current breaker 20 at least until the current breaker 20 transitions from the conductive state to the non-conductive state.

[0046] Furthermore, the isolation circuit 30 and the like may further include switch elements 32a and 32b inserted in the path connecting the primary winding 31a and the secondary winding 31b. This allows the control circuit 40 to connect the control terminals 23a and 23b of the current breaker 20 in a DC manner. As a result, when the detection signal does not exceed the threshold, the control circuit 40 controls the switch elements 32a and 32b to a conductive state, and applies a constant current to the control terminals 23a and 23b of the current breaker 20 via the switch elements 32a and 32b, thereby enabling diagnosis of the current breaker 20.

[0047] In the interruption mode, the control circuit 40 controls the switch elements 32 a and 32 b to transition from a conductive state to a non-conductive state, and then outputs an interruption signal, thereby allowing the current breaker 20 to perform an interruption operation while the current breaker 20 and the control circuit 40 are electrically isolated from each other.

[0048] Alternatively, the isolation circuit 30b may include only the switch elements 32a and 32b inserted in the path connecting the control circuit 40 and the control terminals 23a and 23b of the current breaker 20. This makes it possible to execute the diagnostic mode and the interruption mode without including an isolation transformer, and allows the isolation circuit 30b to be realized at low cost and in a small size.

[0049] Specifically, in the cut-off mode, the control circuit 40 controls the switch elements 32a and 32b to a conductive state, and then outputs a cut-off signal to the control terminals 23a and 23b of the current breaker 20 via the switch elements 32a and 32b. After outputting the cut-off signal, the control circuit 40 controls the switch elements 32a and 32b to transition from a conductive state to a non-conductive state within a predetermined time, thereby causing the current breaker 20 to perform a cut-off operation and suppressing the leakage of high voltage into the control circuit 40.

[0050] Furthermore, the isolation circuit 30c includes fuses 33a and 33b that connect the control circuit 40 and the control terminals 23a and 23b of the current breaker 20, and the fuses 33a and 33b may have the characteristic of transmitting a tripping signal output from the control circuit 40 to the control terminals 23a and 23b of the current breaker 20 when the fuses 33a and 33b are conductive, and melting after transmitting the tripping signal to the control terminals 23a and 23b of the current breaker 20. This makes it possible to execute the diagnostic mode and the tripping mode without including an isolation transformer, and enables the isolation circuit 30c to be realized at low cost and in a small size.

[0051] The electrical circuit interruption device 60 may further include a current breaker 20 and a current detection unit 50. This realizes a complete set of the electrical circuit interruption device 60, which is composed of the current breaker 20, the current detection unit 50, the control circuit 40, the insulation circuit 30, and the like.

[0052] The current breaker 20 may be a pyro fuse, which can instantaneously interrupt a large current in the event of an abnormality, compared to a blown fuse.

[0053] The current detection unit 50 may be a shunt type current sensor. A shunt type current sensor allows the electrical circuit breaker 60 to be made smaller than a current sensor that uses a Hall element.

[0054] While the electrical circuit interruption device according to the present disclosure has been described above based on the embodiments and modifications, the present disclosure is not limited to these embodiments and modifications. As long as they do not deviate from the gist of the present disclosure, various modifications that a person skilled in the art may make to the embodiments or modifications, and other forms constructed by combining some of the components in the embodiments and modifications, are also included within the scope of the present disclosure.

[0055] For example, in the above embodiment and modified example, the current interrupter 20 was a pyro-fuse, but this is not limited to this and may be a breaker, vacuum circuit breaker, gas circuit breaker, etc., as long as it is an active current interrupter having a control terminal.

[0056] Furthermore, in the above-described embodiment and modified example, the current breaker 20 breaks a direct current, but this is not limiting, and the current breaker 20 may be inserted in a path of an alternating current to break the alternating current.

[0057] Furthermore, in the above-described embodiment and modified example, the current detection unit 50 is a resistance detection type such as a conductor piece having a low resistance value, but is not limited to this and may be a magnetic field detection type such as a Hall element.

[0058] Furthermore, in the above-described embodiment and modified example, the switch elements 32 a and 32 b constituting the isolation circuit 30 are configured as two independent switch elements, but this is not limited thereto, and the isolation circuit 30 may be configured as two circuits of switch elements having one common control terminal.

[0059] The present disclosure can be used as an electrical circuit interruption device that drives a current breaker installed on a current path, in particular as an electrical circuit interruption device that can prevent a control circuit from being destroyed by a high voltage leak, for example, as an electrical circuit interruption device that drives a pyro-fuse inserted on a path connecting a battery and a load in an EV.

[0060] 10 Power supply 11 Current path 12 Load 20 Current breaker 21 Housing 21a Cylinder 22 Igniter 23a, 23b Control terminal 24 Projectile 25 Bus bar 25a, 25c Conductor piece 25b Cutting portion 30, 30a to 30c Insulation circuit 31 Insulation transformer 31a Primary winding 31b Secondary winding 32a, 32a1, 32a2, 32b, 32b1, 32b2 Switch element 33a, 33b Fuse 40 Control circuit 41 Amplifier 42 Controller 43 Drive circuit 43a, 43b Transistor 50 Current detection portion 60 Electrical circuit breaker

Claims

1. An electric circuit breaking device that drives a current breaker that has a control terminal and is provided on a current path, a control circuit that outputs a breaker signal for transitioning the current breaker from a conductive state to a non-conductive state based on a detection signal output from a current detection unit that detects a current flowing through the current path; an isolation circuit that is provided on a path connecting the control circuit and the control terminal of the current breaker, that transmits the interruption signal output from the control circuit to the control terminal of the current breaker, and electrically isolates the control circuit from the control terminal of the current breaker; Equipped with When the current breaker transitions from a conductive state to a non-conductive state, the control circuit and the control terminal of the current breaker are electrically insulated by the isolation circuit. Electrical circuit interrupter.

2. the isolation circuit includes an isolation transformer having a primary winding connected to the control circuit and a secondary winding connected to the control terminal of the current breaker.

2. The electrical circuit interruption device according to claim 1.

3. the isolation circuit further includes a switch element; the switch element is inserted in a path connecting the primary winding and the secondary winding.

3. The electrical circuit interrupter according to claim 2.

4. The control circuit When the detection signal does not exceed a threshold value, the switch element is controlled to be in a conductive state; diagnosing the current breaker by applying a current to the control terminal of the current breaker via the switch element; 4. The electrical circuit interrupter according to claim 3.

5. the control circuit outputs the cutoff signal after controlling the switch element to transition from a conductive state to a non-conductive state.

4. The electrical circuit interrupter according to claim 3.

6. the isolation circuit includes a switch element inserted in a path connecting the control circuit and the control terminal of the current breaker.

2. The electrical circuit interruption device according to claim 1.

7. The control circuit controls the switch element to a conductive state, and then outputs the interruption signal to the control terminal of the current breaker via the switch element, and controls the switch element to transition from a conductive state to a non-conductive state within a predetermined time after outputting the interruption signal.

7. The electrical circuit interrupter according to claim 6.

8. the isolation circuit includes a fuse connecting the control circuit and the control terminal of the current breaker; the fuse has a characteristic of transmitting the interruption signal output from the control circuit to the control terminal of the current breaker when the fuse is in a conductive state, and melting after transmitting the interruption signal to the control terminal of the current breaker.

2. The electrical circuit interruption device according to claim 1.

9. the current breaker; the current detection unit; Further comprising: The electrical circuit breaker according to any one of claims 1 to 8.

10. The current interrupter is a pyro fuse.

10. The electrical circuit interruption device of claim 9.

11. The current detection unit is a shunt type current sensor.

10. The electrical circuit interruption device of claim 9.