Shutoff system

Abstract

This shutoff system comprises a bus bar, a shutoff device, a current sensor, and a control circuit. The bus bar is inserted in a power supply route. In the shutoff device, when a portion of the bus bar is divided, the power supply route is shut off. The current sensor measures the current flowing in the bus bar. The control circuit controls the driving of the shutoff device on the basis of the measured value of the current sensor. The current sensor is a contactless type current sensor, and is disposed with a gap between the current sensor and the bus bar.

Description

Isolation System

[0001] The present disclosure relates to a disconnection system for disconnecting a power supply path.

[0002] Patent Document 1 discloses a pyrofuse control circuit. This pyrofuse control circuit includes a current sensing circuit configured to determine whether a current flowing through a conductor exceeds a threshold current. This current sensing circuit is configured to measure a voltage applied to a shunt resistor disposed in the conductor. In other words, the current sensing circuit measures the current flowing through the conductor via the shunt resistor and determines whether the current flowing through the conductor exceeds the threshold.

[0003] Special Publication No. 2021-501551

[0004] However, in the pyro-fuse control circuit disclosed in Patent Document 1, the current flowing through the conductor (bus bar) flows to the shunt resistor, and the flow of current generates heat in the shunt resistor. If the current flowing through the bus bar is large, the heat generated in the shunt resistor also becomes large, requiring a structure to cool the generated heat, which poses a problem of increased costs.

[0005] Therefore, the present disclosure provides a circuit breaking system that can suppress the generation of heat caused by current flowing through a bus bar.

[0006] A circuit breaking system according to one aspect of the present disclosure includes a bus bar, a circuit breaking device, a first current sensor, and a control circuit. The bus bar is inserted into a power supply path. The circuit breaking device interrupts the power supply path when a portion of the bus bar is severed. The first current sensor measures a current flowing through the bus bar. The control circuit controls operation of the circuit breaking device based on a measurement value of the first current sensor. The first current sensor is a non-contact current sensor and is disposed at a distance from the bus bar.

[0007] The interruption system of the present disclosure has the advantage of being able to suppress the generation of heat caused by current flowing through the bus bar.

[0008] FIG. 1 is a diagram showing a schematic configuration of an interruption system according to a first embodiment. FIG. 2 is a schematic view of a current sensor and a bus bar according to the first embodiment as viewed from above. FIG. 3 is a schematic view of a current sensor and a bus bar according to the first embodiment as viewed from the right. FIG. 4 is a diagram showing a schematic configuration of an interruption system according to a second embodiment. FIG. 5 is a diagram showing a schematic configuration of an interruption system according to a third embodiment. FIG. 6 is a diagram showing a schematic configuration of an interruption system according to a fourth embodiment. FIG. 7 is a schematic view of a first current sensor, a second current sensor, and a bus bar according to the fourth embodiment as viewed from the right. FIG. 8 is a diagram showing a schematic configuration of an interruption system according to a fifth embodiment.

[0009] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0010] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, components, arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in the independent claims are described as optional components.

[0011] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales and the like do not necessarily match in each figure. Furthermore, in each figure, the same reference numerals are used for components that are substantially the same as those in other figures, and redundant explanations are omitted or simplified.

[0012] Furthermore, in this specification, terms indicating the relationship between elements, such as orthogonal, parallel, and the same, terms indicating the shape of elements, such as rectangular and circular, as well as numerical values ​​and numerical ranges, are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent (e.g., about 10%).

[0013] (Embodiment 1) The following describes a shutdown system according to embodiment 1. The shutdown system is mounted on a vehicle such as an automobile, and is provided in a power supply path for supplying power from a battery to a load. The shutdown system is a system that shuts off the supply of power when an abnormality occurs in the power supply path.

[0014] The battery is a secondary battery such as a lithium-ion battery. The load is an electrical device such as a motor. The battery supplies DC power to the load via a power supply path by discharging. The battery is also charged by receiving DC power from the load via the power supply path.

[0015] [Configuration] The configuration of the interruption system 1 according to the first embodiment will be described below with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of the interruption system 1 according to the first embodiment. As shown in Fig. 1, the interruption system 1 includes a bus bar 10, an interruption device 20, a substrate 30, a current sensor 40, a control circuit 50, and an ignition circuit 60.

[0016] The busbar 10 is a linear, flat conductor and is disposed so as to penetrate a case 21 that constitutes the outer shell of the circuit breaker 20. The top surface (the upper surface in FIG. 1 ) and bottom surface (the lower surface in FIG. 1 ) of the busbar 10 are wide surfaces that are larger in width than the left side surface (the surface on the near side of the page in FIG. 1 ) and the right side surface (the surface on the far side of the page in FIG. 1 ). Hereinafter, the top surface (or bottom surface) of the busbar 10 will also be referred to as the wide surface 11. Although not shown, a first end of the busbar 10 in the longitudinal direction is connected to the positive (or negative) terminal of a battery, and a second end is connected to one end (or the other end) of a load. In other words, the busbar 10 is inserted into a power supply path PL that connects the positive (or negative) terminal of the battery and one end (or the other end) of the load. The busbar 10 may be a part of the components of the circuit breaker 20.

[0017] The interrupting device 20 is a device that interrupts the supply of power in the power supply path PL. In the first embodiment, the interrupting device 20 is a pyrotechnic interrupting device (a pyrotechnic interrupting device, an irreversible pyrotechnic interrupting device). The interrupting device 20 interrupts the power supply path PL by disconnecting a part of the bus bar 10 based on a disconnection signal output from the ignition circuit 60. Specifically, the interrupting device 20 disconnects the part of the bus bar 10 located inside the interrupting device 20 by a piston housed inside the interrupting device 20, thereby interrupting the power supply path PL.

[0018] More specifically, the circuit breaker 20 includes a case 21 that forms an outer shell, a piston that is movable in a direction perpendicular to the wide surface 11 of the bus bar 10 (the up-and-down direction in FIG. 1 ), and an ignition unit 22 that activates the piston. Note that the piston is not shown in FIG. 1 .

[0019] The case 21 is cylindrical and elongated in a direction perpendicular to the wide surface 11 of the bus bar 10. The bus bar 10 is disposed to pass through the case 21. Inside the case 21, the separated portion of the bus bar 10, a piston, and an ignition unit 22 are disposed. Although the case 21 is shown in FIG. 1 as a rectangular parallelepiped, this does not represent the actual shape.

[0020] Ignition unit 22 is mainly provided inside case 21. A part of ignition unit 22 is exposed to the outside of case 21 as an input terminal that receives a cutoff signal from ignition circuit 60. Ignition unit 22 activates the piston when it receives the cutoff signal from ignition circuit 60, that is, when an abnormality occurs in power supply path PL. The occurrence of an abnormality in power supply path PL here refers to, for example, an overcurrent flowing in power supply path PL, in other words, in bus bar 10, due to a short circuit or the like.

[0021] Specifically, when ignition unit 22 receives a cutoff signal from ignition circuit 60, it ignites the gunpowder to rapidly expand the gas inside case 21, thereby moving the piston at high speed toward a portion of bus bar 10 located inside case 21. As a result, the piston collides with the portion of bus bar 10, and the portion of bus bar 10 is severed, thereby cutting off power supply path PL.

[0022] The substrate 30 has a rectangular, flat plate shape and is made of an electrically insulating material. The substrate 30 is disposed above the bus bar 10. A current sensor 40, a control circuit 50, and an ignition circuit 60 are mounted on the upper surface of the substrate 30. The current sensor 40 is disposed above the bus bar 10 with the electrically insulating substrate 30 sandwiched therebetween, and is therefore disposed at a predetermined distance from the bus bar 10 and electrically insulated from the bus bar 10. In other words, the current sensor 40 is disposed so as not to come into contact with the bus bar 10. The substrate 30 may be disposed on the upper surface of the bus bar 10, or may be disposed so as not to come into contact with the bus bar 10 by being fixed to another member around the interruption system 1, for example.

[0023] Current sensor 40 is a sensor that measures current Ib flowing through bus bar 10 and is a non-contact current sensor that is arranged at a distance from bus bar 10. In the first embodiment, current sensor 40 is particularly a coreless magnetic sensor, and further, is a current sensor that uses a TMR (Tunnel Magnetoresistance) element as the magnetoresistive element. The magnetoresistive element (here, the TMR element) has a magnetic resistance that changes depending on the magnitude of the magnetic flux passing through current sensor 40.

[0024] In the first embodiment, the current sensor 40 is configured by an integrated circuit (IC) incorporating a magnetoresistive element and a signal processing circuit. The signal processing circuit amplifies a potential difference generated by passing a current through the magnetoresistive element, and processes the amplified potential difference to output a signal corresponding to the magnitude of the magnetic flux passing through the current sensor 40. Note that the current flowing through the magnetoresistive element is a current flowing from a power supply for driving the current sensor 40, and is not the current Ib flowing through the bus bar 10. Furthermore, the current flowing through the magnetoresistive element is a very small current compared to the current flowing through the bus bar 10.

[0025] Here, the magnetic flux passing through current sensor 40 changes depending on the magnitude of current Ib flowing through busbar 10. Therefore, current sensor 40 can measure current Ib flowing through busbar 10 based on the magnitude of magnetic resistance of the magnetic resistance element, in other words, the magnitude of magnetic flux, without coming into contact with busbar 10.

[0026] In the first embodiment, current sensor 40 is a magnetic sensor capable of uniaxially detecting magnetic flux passing through current sensor 40. Specifically, current sensor 40 can detect magnetic flux in a single axis along the width direction of wide surface 11 of busbar 10.

[0027] The current sensor 40 is mounted on the substrate 30 and is disposed so as to face the wide surface 11 of the busbar 10, as shown in Fig. 1 . In particular, in the first embodiment, the current sensor 40 is disposed so as to fit inside the wide surface 11 of the busbar 10 in a plan view (i.e., when viewed from a direction perpendicular to the wide surface 11 of the busbar 10), as shown in Fig. 2 . In other words, when viewed from a direction perpendicular to the wide surface 11 of the busbar 10 (when viewed from above), the entire current sensor 40 overlaps the wide surface 11 of the busbar 10. Fig. 2 is a schematic diagram of the current sensor 40 and the busbar 10 according to the first embodiment, as viewed from above. Note that the circuit breaker 20, the substrate 30, the control circuit 50, and the ignition circuit 60 are not shown in Fig. 2 .

[0028] The advantages of arranging the current sensor 40 relative to the bus bar 10 in this manner will be described with reference to Fig. 3. Fig. 3 is a schematic diagram of the current sensor 40 and the bus bar 10 according to the first embodiment, viewed from the right in Fig. 1. Note that Fig. 3 does not illustrate the circuit breaker 20, the circuit board 30, the control circuit 50, and the ignition circuit 60.

[0029] 3, when a current Ib flows through the busbar 10, a magnetic field is generated around the busbar 10. When a current Ib flows through the busbar 10 from left to right in FIG. 1, the direction of this magnetic field is counterclockwise when the busbar 10 is viewed from the right. Therefore, a magnetic flux φ0 generated by the current Ib flowing through the busbar 10 passes through a current sensor 40 disposed above (or below) the busbar 10.

[0030] 3, in the space facing the inside of the wide surface 11 of the busbar 10, the direction of the magnetic flux φ0 hardly changes. In other words, this space is a place where the change in the magnetic flux φ0 generated by the current Ib flowing through the busbar 10 is relatively small. Therefore, if the current sensor 40 is placed in this space, even if the position of the current sensor 40 is shifted during design, the magnetic flux φ0 passing through the current sensor 40 hardly changes, which is advantageous in that the positional shift of the current sensor 40 is unlikely to affect the measurement accuracy of the current sensor 40.

[0031] The control circuit 50 is a circuit that controls the operation of the circuit breaker 20 based on the measurement value of the current sensor 40. The control circuit 50 is configured, for example, by an IC. The control circuit 50 is also electrically connected to the current sensor 40 and configured to acquire the measurement value of the current sensor 40. In the first embodiment, the control circuit 50 compares the measurement value of the current sensor 40, i.e., the current value of the current Ib flowing through the bus bar 10, with a threshold value pre-stored in a memory or the like, and outputs an electrical signal to the ignition circuit 60 when the current value exceeds the threshold value. This electrical signal is amplified by the ignition circuit 60, and the amplified electrical signal is input to the ignition unit 22 of the circuit breaker 20 as a circuit breaker signal. This causes the ignition unit 22 of the circuit breaker 20 to operate a piston.

[0032] In this way, the control circuit 50 monitors whether an overcurrent is flowing through the bus bar 10, that is, whether an abnormality has occurred in the power supply path PL, by referring to the measurement value of the current sensor 40. When an overcurrent is flowing through the bus bar 10, the control circuit 50 outputs a cutoff signal to the ignition unit 22 of the breaker 20 via the ignition circuit 60, thereby driving the breaker 20 to cut off a part of the bus bar 10 and cut off the power supply path PL.

[0033] In addition, when the control circuit 50 is connected to be able to communicate with, for example, an ECU (Electronic Control Unit) mounted on the vehicle, the control circuit 50 may output an electrical signal to the ignition circuit 60 when it receives a signal output from the ECU notifying the occurrence of an abnormality.

[0034] The ignition circuit 60 is a circuit that amplifies the electrical signal output from the control circuit 50 and outputs the amplified electrical signal (i.e., a cutoff signal) to the ignition unit 22 of the cutoff device 20. The ignition circuit 60 is configured, for example, with an IC. The ignition circuit 60 amplifies the electrical signal output from the control circuit 50 to a level that is sufficient to ignite the explosives provided in the ignition unit 22.

[0035] [Advantages, etc.] The advantages of the interruption system 1 according to the first embodiment will be described below. As described above, in the interruption system 1 according to the first embodiment, the current sensor 40 is a non-contact current sensor that is disposed at a distance from the bus bar 10. Therefore, the current Ib flowing through the bus bar 10 does not flow through the current sensor 40. Therefore, even in an application in which a large current flows through the power supply path PL, a large current does not flow through the current sensor 40, and excessive heat is not generated in the current sensor 40. Therefore, the interruption system 1 according to the first embodiment has the advantage of being able to suppress the generation of heat caused by the current Ib flowing through the bus bar 10. Therefore, the interruption system 1 according to the first embodiment does not require a structure for cooling the heat generated by the current sensor 40, and therefore the manufacturing cost of the interruption system 1 can be reduced.

[0036] Furthermore, in the interruption system 1 according to the first embodiment, the current sensor 40 is a coreless current sensor. Therefore, the current sensor 40 does not require a magnetic core, and therefore there is no measurement error due to magnetic hysteresis, which has the advantage of providing higher measurement accuracy for the current Ib flowing through the busbar 10 compared to a current sensor that uses a magnetic core.

[0037] (Embodiment 2) An interruption system 1A according to embodiment 2 will be described below with reference to Fig. 4. Fig. 4 is a diagram showing a schematic configuration of the interruption system 1A according to embodiment 2. The interruption system 1A according to embodiment 2 differs from the interruption system 1 according to embodiment 1 mainly in that the interruption system 1A according to embodiment 2 includes a plurality of current sensors 40. Below, a description of the points common to the interruption system 1 according to embodiment 1 will be omitted.

[0038] 4, the interruption system 1A includes a plurality of (here, two) current sensors 40. Hereinafter, one of the two current sensors 40 will also be referred to as a first current sensor 41, and the other current sensor 40 will also be referred to as a second current sensor 42.

[0039] Each of the first current sensor 41 and the second current sensor 42 is a magnetic sensor capable of detecting magnetic flux along two axes. Specifically, each of the first current sensor 41 and the second current sensor 42 can detect magnetic flux along two axes: an axis along the width direction of the wide surface 11 of the bus bar 10, and an axis along a direction perpendicular to the wide surface 11 of the bus bar 10.

[0040] The first current sensor 41 and the second current sensor 42 are both arranged to face the top surface of the busbar 10. In other words, the multiple current sensors 40 are all arranged on the same side facing the wide surface 11 (here, above the wide surface 11). In particular, in the second embodiment, the first current sensor 41 and the second current sensor 42 are arranged to fit inside the wide surface 11 of the busbar 10 in a plan view (that is, when viewed from a direction perpendicular to the wide surface 11 of the busbar 10).

[0041] The first current sensor 41 and the second current sensor 42 are arranged side by side along the longitudinal direction of the bus bar 10. Therefore, the magnetic flux generated by the current Ib flowing through the bus bar 10 and passing through the first current sensor 41 and the magnetic flux generated by the current Ib flowing through the bus bar 10 and passing through the second current sensor 42 are almost the same in magnitude and direction. Hereinafter, these magnetic fluxes will be referred to as "magnetic flux φ1."

[0042] In the second embodiment, the first current sensor 41 and the second current sensor 42 are the same type of sensor. However, the first current sensor 41 and the second current sensor 42 are arranged in a positional relationship rotated 180 degrees from each other in a plane parallel to the wide surface 11 of the busbar 10. Therefore, the first current sensor 41 and the second current sensor 42 output current measurements with different polarities. Here, for the same magnetic flux, the first current sensor 41 outputs a positive measurement value, while the second current sensor 42 outputs a negative measurement value.

[0043] The control circuit 50 is electrically connected to each of the first current sensor 41 and the second current sensor 42, and is configured to acquire the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42. The control circuit 50 calculates the current value of the current Ib flowing through the bus bar 10 based on the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42, and compares the calculated current value with a threshold value to monitor whether an overcurrent is flowing through the bus bar 10.

[0044] That is, the control circuit 50 in the second embodiment differs from the control circuit 50 in the first embodiment in that the control circuit 50 executes a process of calculating the current value of the current Ib flowing through the busbar 10 using the measured values ​​of each of the multiple current sensors 40. Specifically, the control circuit 50 calculates the difference between the measured value of the first current sensor 41 and the measured value of the second current sensor 42, and divides the calculated difference by 2 to calculate the current value of the current Ib flowing through the busbar 10.

[0045] In the space inside the vehicle in which the interruption system is installed, there are conductors other than the bus bar 10 and electrical components such as relays, and magnetic flux generated by current flowing through these components reaches the interruption system as external noise. Therefore, if magnetic flux passes through the current sensor 40 as external noise, the measurement accuracy of the current Ib flowing through the bus bar 10 may decrease.

[0046] Therefore, in embodiment 2, as described above, the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 are referred to to remove at least a portion of the external noise (i.e., noise canceling), thereby suppressing a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0047] The noise canceling process by the control circuit 50 will be explained below using mathematical expressions. If the measurement value of the first current sensor 41 is "I1" and the measurement value of the second current sensor 42 is "I2," the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 are respectively expressed by the following mathematical expressions (1) and (2).

[0048] I1=f(φ1)+f(φN1) (1) I2=f(-φ1)+f(φN1)=-f(φ1)+f(φN1) (2) In formulas (1) and (2), "f(φ1)" represents the current value corresponding to the magnetic flux φ1 passing through the first current sensor 41, and "f(-φ1)" represents the current value corresponding to the magnetic flux φ1 passing through the second current sensor 42. As described above, the first current sensor 41 and the second current sensor 42 output current values ​​of different polarities, and therefore "f(-φ1)" corresponds to "-f(φ1)."

[0049] In addition, in formulas (1) and (2), "f(φN1)" represents a current value corresponding to the magnetic flux φN1 passing through each of the first current sensor 41 and the second current sensor 42. Here, the magnetic flux φN1 is the magnetic flux of the external noise that is along a direction perpendicular to the wide surface 11 of the busbar 10.

[0050] If the current value of the current Ib flowing through the busbar 10 is "Ib", the current value "Ib" is expressed by the following equation (3).

[0051] Ib=(I1-I2) / 2=f(φ1) (3) As described above, by calculating the difference between the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 and dividing the calculated difference by 2, it is possible to cancel out the magnetic flux of the external noise that is along the direction perpendicular to the wide surface 11 of the busbar 10. In other words, the interruption system 1A according to the second embodiment has the advantage that by referring to the measurement values ​​of the first current sensor 41 and the second current sensor 42, which are capable of detection in two axes, it is possible to remove at least a portion of the external noise and suppress a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0052] In the interruption system 1A according to the second embodiment, the control circuit 50 may further have a function of detecting a failure of the current sensor 40. Specifically, the control circuit 50 calculates the difference between the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 and monitors whether the calculated difference falls within a predetermined threshold range stored in a memory or the like. If the calculated difference falls outside the predetermined threshold range, the control circuit 50 detects that one of the first current sensor 41 and the second current sensor 42 has failed. In this case, the control circuit 50 may notify the user of the abnormality and replace the first current sensor 41 and the second current sensor 42 with new ones, thereby improving the situation in which the current Ib flowing through the bus bar 10 cannot be measured accurately.

[0053] Furthermore, the interruption system 1A according to the second embodiment may include three current sensors 40. In this case, if the control circuit 50 has a function of detecting a failure of a current sensor 40, it can identify which current sensor 40 is faulty. For example, the control circuit 50 selects two of the three current sensors 40, calculates the difference between the measured values ​​of the selected two current sensors 40, and monitors whether the calculated difference falls within a predetermined threshold range. Since there are six combinations of selecting two current sensors 40 from the three current sensors 40, the control circuit 50 monitors whether the calculated difference falls within a predetermined threshold range for each of the six combinations.

[0054] Here, if one of the three current sensors 40 fails, the calculated difference falls outside the predetermined threshold range in each of the two of the six combinations including the failed current sensor 40, and the control circuit 50 can identify the failed current sensor 40. In this case, by replacing only the failed current sensor 40 with a new one, it is possible to improve the situation in which the current Ib flowing through the busbar 10 cannot be measured accurately.

[0055] (Embodiment 3) An interruption system 1B according to embodiment 3 will be described below with reference to Fig. 5. Fig. 5 is a diagram showing a schematic configuration of the interruption system 1B according to embodiment 3. The interruption system 1B according to embodiment 3 differs from the interruption system 1A according to embodiment 2 mainly in the arrangement of the multiple current sensors 40. Below, a description of the points common to the interruption system 1A according to embodiment 2 will be omitted.

[0056] In the third embodiment, the first current sensor 41 and the second current sensor 42 are both magnetic sensors capable of detecting magnetic flux in one axis, similar to the current sensor 40 in the first embodiment. Specifically, the first current sensor 41 and the second current sensor 42 are both capable of detecting magnetic flux in an axis along the width direction of the wide surface 11 of the busbar 10.

[0057] The first current sensor 41 and the second current sensor 42 are both arranged to face the top surface of the busbar 10. In other words, the multiple current sensors 40 are all arranged on the same side facing the wide surface 11 (here, above the wide surface 11). In particular, the first current sensor 41 is arranged to fit inside the wide surface 11 of the busbar 10 in a plan view (i.e., when viewed from a direction perpendicular to the wide surface 11 of the busbar 10).

[0058] On the other hand, the second current sensor 42 is disposed at a predetermined distance from the busbar 10. Specifically, the second current sensor 42 and the first current sensor 41 are disposed side by side along the width direction of the wide surface 11 of the busbar 10, and are disposed so that the magnetic flux φ3 is much smaller than the magnetic flux φ2. Here, the magnetic flux φ2 is a magnetic flux that is generated when the current Ib flows through the busbar 10 and passes through the first current sensor 41. The magnetic flux φ3 is a magnetic flux that is generated when the current Ib flows through the busbar 10 and passes through the second current sensor 42, and has the same direction as the magnetic flux φ2. For example, the magnetic flux φ3 is about one-tenth of the magnetic flux φ2. Furthermore, the magnetic flux of the external noise that passes through the first current sensor 41 and the magnetic flux of the external noise that passes through the second current sensor 42 are almost the same in magnitude and direction. Hereinafter, the magnetic flux of these external noises will be referred to as the "magnetic flux φN2."

[0059] In the third embodiment, the first current sensor 41 and the second current sensor 42 are the same type of sensor and have the same polarity of the measured current values. That is, in the third embodiment, the first current sensor 41 and the second current sensor 42 are arranged in a plane parallel to the wide surface 11 of the busbar 10 without being rotated 180 degrees relative to each other.

[0060] In the third embodiment, the control circuit 50 calculates the difference between the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42, thereby calculating the current value of the current Ib flowing through the bus bar 10. That is, in the third embodiment, similar to the second embodiment, the control circuit 50 refers to the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 and removes at least a part of the external noise (i.e., performs noise cancellation), thereby suppressing a decrease in the measurement accuracy of the current Ib flowing through the bus bar 10.

[0061] The noise canceling process by the control circuit 50 will be explained below using mathematical expressions. If the measurement value of the first current sensor 41 is "I1" and the measurement value of the second current sensor 42 is "I2," the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 are respectively expressed by the following mathematical expressions (4) and (5).

[0062] I1 = f(φ2) + f(φN2) (4) I2 = f(φ3) + f(φN2) (5) In formula (4), "f(φ2)" represents a current value corresponding to the magnetic flux φ2 passing through the first current sensor 41. In formula (5), "f(φ3)" represents a current value corresponding to the magnetic flux φ3 passing through the second current sensor 42. In formulas (4) and (5), "f(φN2)" represents a current value corresponding to the magnetic flux φN2 passing through each of the first current sensor 41 and the second current sensor 42. Here, the magnetic flux φN2 is the magnetic flux of the external noise that is along the width direction of the wide surface 11 of the busbar 10.

[0063] If the current value of the current Ib flowing through the busbar 10 is "Ib", the current value "Ib" is expressed by the following formula (6). Note that in formula (6), since the magnetic flux φ3 is much smaller than the magnetic flux φ2, "f(φ2)>>f(φ3)" holds, and "f(φ3)" is ignored.

[0064] Ib = (I1 - I2) = f(φ2) - f(φ3) ≈ f(φ2) (6) As described above, by calculating the difference between the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42, it is possible to cancel out the magnetic flux that is part of the external noise and that is aligned in the width direction of the wide surface 11 of the busbar 10. In other words, the interruption system 1B according to the third embodiment has the advantage that by referring to the measurement values ​​of the first current sensor 41 and the second current sensor 42, which are detectable in one axis, it is possible to remove at least a portion of the external noise and suppress a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0065] In the interruption system 1B according to the third embodiment, similarly to the interruption system 1A according to the second embodiment, the control circuit 50 may further have a function of detecting a failure of the current sensor 40. Furthermore, similarly to the interruption system 1A according to the second embodiment, the interruption system 1B according to the third embodiment may include three current sensors 40.

[0066] (Fourth Embodiment) An interruption system 1C according to a fourth embodiment will be described below with reference to Fig. 6. Fig. 6 is a diagram showing a schematic configuration of the interruption system 1C according to the fourth embodiment. The interruption system 1C according to the fourth embodiment differs from the interruption system 1A according to the second embodiment mainly in the arrangement of the multiple current sensors 40. Below, a description of the points common to the interruption system 1A according to the second embodiment will be omitted.

[0067] In the fourth embodiment, the first current sensor 41 and the second current sensor 42 are both magnetic sensors capable of detecting magnetic flux in one axis, similar to the current sensor 40 in the first embodiment. Specifically, the first current sensor 41 and the second current sensor 42 are both capable of detecting magnetic flux in an axis along the width direction of the wide surface 11 of the busbar 10.

[0068] In the fourth embodiment, the substrate 30 is disposed such that its mounting surface is parallel to a direction perpendicular to the wide surface 11 of the busbar 10 and the busbar 10 passes through it. The first current sensor 41 and the second current sensor 42 are disposed on either side of the busbar 10 in a direction perpendicular to the wide surface 11 of the busbar 10. Specifically, the first current sensor 41 is disposed above the busbar 10, and the second current sensor 42 is disposed below the busbar 10. The first current sensor 41 and the second current sensor 42 are disposed side by side in a direction perpendicular to the wide surface 11 of the busbar 10. Therefore, in the fourth embodiment, the magnetic flux generated by a current flowing through the busbar 10 and passing through the first current sensor 41 and the magnetic flux generated by a current flowing through the busbar 10 and passing through the second current sensor 42 are almost the same in magnitude but have different directions. Hereinafter, these magnetic fluxes will be referred to as "magnetic flux φ4."

[0069] As shown in Fig. 7, the magnetic flux of the external noise passing through the first current sensor 41 and the magnetic flux of the external noise passing through the second current sensor 42 are almost the same in magnitude and direction. Fig. 7 is a schematic diagram of the first current sensor 41, the second current sensor 42, and the bus bar 10 according to the fourth embodiment, viewed from the right. Note that Fig. 7 does not illustrate the circuit breaker 20, the circuit board 30, the control circuit 50, and the ignition circuit 60. Hereinafter, the magnetic flux of these external noises will be referred to as "magnetic flux φN3."

[0070] In the fourth embodiment, the first current sensor 41 and the second current sensor 42 are the same type of sensor and have the same polarity of the measured current values. That is, in the fourth embodiment, the first current sensor 41 and the second current sensor 42 are arranged in a plane perpendicular to the wide surface 11 of the busbar 10 without being rotated 180 degrees relative to each other.

[0071] In the fourth embodiment, the control circuit 50 calculates the difference between the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42, and divides the calculated difference by 2 to calculate the current value of the current Ib flowing through the bus bar 10. That is, in the fourth embodiment, similar to the second and third embodiments, the control circuit 50 refers to the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 to remove at least a part of the external noise (i.e., noise canceling), thereby suppressing a decrease in the measurement accuracy of the current Ib flowing through the bus bar 10.

[0072] The noise canceling process by the control circuit 50 will be explained below using mathematical expressions. If the measurement value of the first current sensor 41 is "I1" and the measurement value of the second current sensor 42 is "I2," the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 are respectively expressed by the following mathematical expressions (7) and (8).

[0073] I1 = f(φ4) + f(φN3) ... (7) I2 = f(-φ4) + f(φN3) = -f(φ4) + f(φN3) ... (8) If the current value of the current Ib flowing through the busbar 10 is "Ib", the current value "Ib" is expressed by the following equation (9).

[0074] Ib=(I1-I2) / 2=f(φ4) (9) As described above, by calculating the difference between the measurement value of the first current sensor 41 and the measurement value of the second current sensor 42 and dividing the calculated difference by 2, it is possible to cancel out the magnetic flux of the external noise that is along the width direction of the wide surface 11 of the busbar 10. In other words, the interruption system 1C according to the fourth embodiment has the advantage that by referring to the measurement values ​​of the first current sensor 41 and the second current sensor 42, which are detectable in one axis, it is possible to remove at least a portion of the external noise and suppress a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0075] In the interruption system 1C according to the fourth embodiment, similarly to the interruption system 1A according to the second embodiment, the control circuit 50 may further have a function of detecting a failure of the current sensor 40. Furthermore, similarly to the interruption system 1A according to the second embodiment, the interruption system 1C according to the fourth embodiment may include three current sensors 40.

[0076] (Fifth Embodiment) An interruption system 1D according to a fifth embodiment will be described below with reference to Fig. 8. Fig. 8 is a diagram showing a schematic configuration of the interruption system 1D according to the fifth embodiment. In Fig. 8, solid arrows represent magnetic flux generated by a current Ib flowing through the bus bar 10, and wide dashed arrows represent magnetic flux as external noise. Note that Fig. 8 does not show the interruption device 20. The interruption system 1D according to the fifth embodiment differs from the interruption system 1C according to the fourth embodiment mainly in that the interruption system 1D includes two circuit boards 30 and 31. Below, a description of the points common to the interruption system 1C according to the fourth embodiment will be omitted.

[0077] As in the first embodiment, one of the two boards 30, 31, board 30, is disposed above bus bar 10, and the other board 31 is disposed below bus bar 10. Boards 30, 31 are both disposed so that their mounting surfaces are parallel to wide surface 11 of bus bar 10. A first current sensor 41 is disposed on one board 30, and a second current sensor 42 is disposed on the other board 31. One board 30 and the other board 31 are mechanically and electrically connected by a connector 70.

[0078] 8 , in the fifth embodiment, the first current sensor 41 and the second current sensor 42 are both arranged so that their thickness directions are aligned with a direction perpendicular to the wide surface 11. In other words, the first current sensor 41 and the second current sensor 42 are arranged so that their mounting surfaces on the respective substrates 30 and 31 are parallel to the wide surface 11 of the bus bar 10. Therefore, in the fifth embodiment, the magnetic flux passing through each of the first current sensor 41 and the second current sensor 42 is larger than in the fourth embodiment, which has the advantage of improving the measurement accuracy of the current Ib flowing through the bus bar 10.

[0079] (Summary) As described above, the interruption systems 1, 1A, 1B, 1C, and 1D of the present disclosure include a bus bar 10, an interruption device 20, a current sensor 40, and a control circuit 50. The bus bar 10 is inserted into the power supply path PL. The interruption device 20 interrupts the power supply path PL when a portion of the bus bar 10 is severed. The current sensor 40 measures the current flowing through the bus bar 10. The control circuit 50 controls the operation of the interruption device 20 based on the measurement value of the current sensor 40. The current sensor 40 is a non-contact current sensor and is disposed at a distance from the bus bar 10.

[0080] According to this configuration, the current Ib flowing through the bus bar 10 does not flow through the current sensor 40, so even in an application where a large current flows through the power supply path PL, a large current does not flow through the current sensor 40, and excessive heat is not generated in the current sensor 40. This has the advantage of being able to suppress the generation of heat caused by the current Ib flowing through the bus bar 10.

[0081] Furthermore, it is preferable that the current sensor 40 be disposed so as to face the wide surface 11 of the bus bar 10 .

[0082] With this configuration, compared to when the current sensor 40 is positioned opposite the side (narrow side) of the busbar 10, the magnetic flux generated by the current Ib flowing through the busbar 10 is more likely to pass through the current sensor 40, which has the advantage of improving the measurement accuracy of the current Ib flowing through the busbar 10.

[0083] Furthermore, it is preferable that the current sensor 40 be arranged so as to fit inside the wide surface 11 when viewed from a direction perpendicular to the wide surface 11. In other words, it is preferable that the current sensor 40 be arranged so that the entire current sensor overlaps the wide surface 11 when viewed from a direction perpendicular to the wide surface 11.

[0084] With this configuration, even if the current sensor 40 is misaligned during design, the magnetic flux passing through the current sensor 40 hardly changes, which has the advantage that the misalignment of the current sensor 40 is unlikely to affect the measurement accuracy of the current sensor 40.

[0085] Furthermore, the first current sensor 41 and the second current sensor 42 are located on the same side of the wide surface 11 of the busbar 10 and face the wide surface 11, and each of the first current sensor 41 and the second current sensor 42 is capable of detecting magnetic flux along two axes: an axis along the width direction of the wide surface 11 and an axis along a direction perpendicular to the wide surface 11, and it is preferable that the first current sensor 41 and the second current sensor 42 have current measurement values ​​with polarities that are different from each other.

[0086] According to this configuration, by referring to the measurement values ​​of the first current sensor 41 and the second current sensor 42, which can be detected in two axes, it is possible to remove at least a portion of the external noise, and it is possible to suppress a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0087] Furthermore, it is preferable that the first current sensor 41 and the second current sensor 42 are arranged on the same plane parallel to the wide surface 11, and that on the same plane, the first current sensor 41 is arranged rotated 180 degrees relative to the second current sensor.

[0088] This configuration has the advantage that it is possible to use two current sensors of the same type to realize a first current sensor 41 and a second current sensor 42 whose current measurement values ​​have different polarities, thereby eliminating the need to prepare current sensors of different types.

[0089] Furthermore, it is preferable that the first current sensor 41 and the second current sensor 42 are located on the same side of the wide surface 11 of the busbar 10, the first current sensor 41 is arranged so as to face the wide surface 11 of the busbar 10, and the second current sensor 42 is arranged farther away from the busbar 10 than the first current sensor 41.

[0090] According to this configuration, by referring to the measurement values ​​of the first current sensor 41 and the second current sensor 42, which can be detected in one axis, it is possible to remove at least a portion of the external noise, and it is possible to suppress a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0091] Furthermore, it is preferable that the first current sensor 41 and the second current sensor 42 are arranged on the same plane perpendicular to the direction in which the bus bar 10 extends, and that the bus bar 10 extends between the first current sensor 41 and the second current sensor 42.

[0092] According to this configuration, by referring to the measurement values ​​of the first current sensor 41 and the second current sensor 42, which can be detected in one axis, it is possible to remove at least a portion of the external noise, and it is possible to suppress a decrease in the measurement accuracy of the current Ib flowing through the busbar 10.

[0093] Furthermore, it is preferable that the first current sensor 41 and the second current sensor 42 are both arranged so that their thickness directions coincide with a direction perpendicular to the wide surface 11 .

[0094] According to this configuration, the magnetic flux passing through each of the first current sensor 41 and the second current sensor 42 is increased, which has the advantage of improving the measurement accuracy of the current Ib flowing through the bus bar 10.

[0095] The current sensor 40 may also be a coreless magnetic sensor.

[0096] With this configuration, the current sensor 40 does not require a magnetic core, so there is no measurement error due to magnetic hysteresis, and it has the advantage of being able to measure the current Ib flowing through the busbar 10 with higher accuracy than a current sensor that uses a magnetic core.

[0097] The current sensor 40 may also be a magnetic sensor using a tunnel magnetoresistive element.

[0098] According to this configuration, the current sensor 40 has a higher sensitivity to magnetism than a magnetic sensor that uses, for example, a GMR (Giant Magnetoresistance) element, and therefore has the advantage of being able to improve the measurement accuracy of the current Ib flowing through the bus bar 10.

[0099] (Other Embodiments) Although the blocking systems and the like according to Embodiments 1 to 5 have been described above, the present disclosure is not limited to these embodiments. As long as they do not deviate from the spirit of the present disclosure, various modifications that a person skilled in the art can conceive of to each embodiment and forms constructed by combining components of different embodiments may also be included in the present disclosure.

[0100] For example, in the first embodiment, current sensor 40 does not have to be disposed so as to face wide surface 11 of busbar 10. In other words, current sensor 40 may be disposed so as to face a side surface of busbar 10. Even in this case, as long as current sensor 40 is disposed so that magnetic flux φ0 generated by current Ib flowing through busbar 10 passes through it, it is possible to measure current Ib flowing through busbar 10.

[0101] For example, in the second embodiment, the first current sensor 41 and the second current sensor 42 may be realized by different types of current sensors that measure currents with different polarities.

[0102] For example, in each of the first to fifth embodiments, the control circuit 50 and the ignition circuit 60 may be integrated. For example, the control circuit 50 may have the function of the ignition circuit 60.

[0103] For example, in each of the first to fifth embodiments, the current sensor 40 may be a current sensor that uses an AMR (Anisotropic Magnetoresistive) element or a GMR (Giant Magnetoresistive) element as the magnetoresistive element.

[0104] The interruption system is mounted, for example, on a vehicle such as an automobile, or on an electrical appliance such as a home appliance. Examples of vehicles include vehicles equipped with a battery, such as a BEV (Battery Electric Vehicle) and a PHEV (Plug-in Hybrid Vehicle). The interruption system may also be mounted on an object having an electrical circuit other than a vehicle or an electrical appliance. Furthermore, the interruption system in each of the above embodiments may be used, for example, to interrupt an overcurrent in a power storage system or a power transmission system.

[0105] The present disclosure is useful for a cutoff system that cuts off a power supply path when an overcurrent occurs.

[0106] 1, 1A, 1B, 1C, 1D Breaking system 10 Bus bar 11 Wide surface 20 Breaking device 21 Case 22 Ignition unit 30, 31 Circuit board 40 Current sensor 41 First current sensor 42 Second current sensor 50 Control circuit 60 Ignition circuit 70 Connector φ1, φ2, φ3, φ4, φN1, φN2, φN3 Magnetic flux Ib Current PL Power supply path

Claims

1. A bus bar to be inserted into the power supply path; a breaker that breaks the power supply path when a portion of the bus bar is cut off; a first current sensor for measuring a current flowing through the bus bar; a control circuit for controlling operation of the interrupter based on a measurement value of the first current sensor; Equipped with The first current sensor is a non-contact type current sensor and is disposed at a distance from the bus bar. Shutdown system.

2. The bus bar has a wide surface and a narrow surface that is narrower than the wide surface, The current sensor is disposed so as to face the wide surface of the bus bar. The isolation system of claim 1 .

3. the first current sensor is disposed so that the entirety of the first current sensor overlaps the wide surface when viewed in a direction perpendicular to the wide surface, The isolation system of claim 2 .

4. Further comprising a second current sensor; the first current sensor and the second current sensor are located on the same side of the wide surface of the bus bar and face the wide surface; Each of the first current sensor and the second current sensor is capable of detecting magnetic flux along two axes, an axis along a width direction of the wide surface and an axis along a direction perpendicular to the wide surface, The first current sensor and the second current sensor have polarities of the measured current values ​​that are different from each other. The isolation system of claim 2 .

5. the first current sensor and the second current sensor are disposed in the same plane parallel to the wide surface; On the same surface, the first current sensor is disposed rotated 180 degrees relative to the second current sensor. The isolation system of claim 4.

6. Further comprising a second current sensor; the first current sensor and the second current sensor are located on the same side of a broad surface of the bus bar; the first current sensor is disposed so as to face a wide surface of the bus bar, The second current sensor is disposed farther away from the bus bar than the first current sensor. The isolation system of claim 1 .

7. Further comprising a second current sensor; the first current sensor and the second current sensor are disposed on the same plane perpendicular to a direction in which the bus bar extends, the bus bar extends between the first current sensor and the second current sensor; The isolation system of claim 1 .

8. the first current sensor and the second current sensor are both arranged such that a thickness direction thereof coincides with a direction perpendicular to a wide surface of the bus bar. The isolation system of claim 7.

9. The first current sensor is a coreless type magnetic sensor. The blocking system according to any one of claims 1 to 3.

10. The first current sensor is a magnetic sensor using a tunnel magnetoresistance element. The isolation system of claim 9.

11. the first current sensor and the second current sensor are coreless magnetic sensors; An isolation system according to any one of claims 4 to 8.

12. the first current sensor and the second current sensor are magnetic sensors using tunnel magnetoresistance elements; The isolation system of claim 11.

13. The interrupter is an irreversible pyrotechnic interrupter. An isolation system according to any one of claims 1 to 8.