Direct-current short-circuit protection device

Abstract

The present invention is provided with: a fuse having a bus bar and cutting off the bus bar in response to an ignition signal; a first current detection unit that has a first resistance unit and detects a current flowing through the bus bar; and a second current detection unit having a second resistance unit for detecting a current flowing through the bus bar, the first resistance unit and the second resistance unit being integrated with the bus bar so as to flow a current of the same magnitude as the current flowing through the bus bar, and configured to detect a current flowing through the bus bar in response to the ignition signal. The bus bar is cut off between the first current detection unit and the second current detection unit, or the first resistor unit of the first current detection unit is cut off.

Description

Technical Field

[0001] The present disclosure relates to a direct current short circuit protection device. Background Art

[0002] Patent Document 1 describes a technique for miniaturizing a circuit breaker device by integrating a sensor for current detection with the circuit breaker device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-136055 Summary of the invention

[0006] However, when a sensor composed of a shunt resistor or the like is built into the circuit breaker device described in Patent Document 1, there is a problem that when current flows through the shunt resistor, the shunt resistor generates a large amount of heat, which is difficult to dissipate. In particular, when an active fuse is installed in a vehicle such as an electric vehicle, a large current needs to be passed, which generates a large amount of heat, and a heat dissipation countermeasure is required.

[0007] Therefore, the present disclosure provides a DC short-circuit protection device that can easily dissipate heat.

[0008] A DC short-circuit protection device of one embodiment of the present invention comprises: a fuse having a bus bar, which cuts off the bus bar in response to an ignition signal; a first current detection unit having a first resistor unit, which detects the current flowing through the bus bar; and a second current detection unit having a second resistor unit, which detects the current flowing through the bus bar, wherein the first resistor unit and the second resistor unit are integrated with the bus bar in such a manner that a current of the same magnitude as the current flowing through the bus bar flows through the first resistor unit, and in response to the ignition signal, the bus bar is cut off between the first current detection unit and the second current detection unit, or the first resistor unit of the first current detection unit is cut off.

[0009] According to the DC short-circuit protection device of one aspect of the present disclosure, heat can be easily dissipated. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural diagram showing an example of a DC short-circuit protection device according to an embodiment.

[0011] Figure 2 It is a perspective view of the active fuse in the first example.

[0012] Figure 3 It is a partial cross-sectional view of the active fuse in the first example.

[0013] Figure 4It is a perspective view of the active fuse in the second example.

[0014] Figure 5 It is a partial cross-sectional view of the active fuse in the third example.

[0015] Figure 6 It is a partial cross-sectional view of the active fuse in the fourth example.

[0016] Figure 7 It is a bottom view of the bus bar in the fourth example.

[0017] Figure 8 It is a diagram for explaining the cross-sectional structure of the bus bar in the fourth example.

[0018] Fig. 9 4 is a top view of the bus bar in the fifth example. DETAILED DESCRIPTION

[0019] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0020] In addition, the embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, configuration positions and connection methods of the components shown in the following embodiments are examples and are not intended to limit the present disclosure.

[0021] (Implementation Method)

[0022] use Figure 1 A DC short-circuit protection device 1 according to the embodiment will be described.

[0023] Figure 1 It is a structural diagram showing an example of the DC short-circuit protection device 1 according to the embodiment.

[0024] The DC short-circuit protection device 1 is installed in a vehicle such as an electric vehicle that uses electric power for propulsion drive. A high-voltage battery is installed in a vehicle such as an electric vehicle, and electric power is supplied from the battery to a load such as an electric motor, thereby performing propulsion drive of the vehicle such as the electric vehicle. When an accident occurs, a large current caused by a short-circuit abnormality flows in the path connecting the battery and the load, and the battery may smoke or catch fire. Therefore, the DC short-circuit protection device 1 is provided to disconnect the path.

[0025] The DC short-circuit protection device 1 includes an active fuse 10 and a disconnection control circuit 20 .

[0026] The active fuse 10 is a device for cutting off the path connecting the battery and the load when a large current caused by a short circuit anomaly flows through the path, such as a smart fuse. The smart fuse contains gunpowder, which is ignited based on a control signal from the outside, thereby irreversibly cutting off the busbar by the explosive force caused by the ignition of the gunpowder to cut off the current. The active fuse 10 has a cutter 11, a busbar 12, and a plurality of current detection units. Here, two current detection units 13a and 13b are shown as the plurality of current detection units, but the plurality of current detection units may be more than three. In addition, when the number of current detection units is large, the detection signal of each current detection unit needs to be processed, and the processing load increases. Therefore, in the present disclosure, an example is described in which the plurality of current detection units are not more than four but two or three.

[0027] The bus bar 12 is a long conductor bar connected (e.g., fastened) to a path connecting a battery and a load and serving as a part of the path. The cutter 11 cuts the bus bar 12 by an ignition signal from the cutoff control circuit 20. Since the bus bar 12 is a part of the path, the path can be cut off by cutting the bus bar 12.

[0028] Figure 2 1 is a perspective view of an example of an active fuse 10. Figure 2 As shown, the current detection unit 13a has a resistor unit 131a, and the current detection unit 13b has a resistor unit 131b. The current detection unit 13a and the current detection unit 13b are current sensors that detect the current flowing through the busbar 12, respectively. The resistor units 131a and 131b are integrated with the busbar 12 in a manner that a current of the same magnitude as the current flowing through the busbar 12 flows. An example of integration is described below. The current detection units 13a and 13b convert the current flowing through the resistor units 131a and 131b into a voltage, respectively, thereby detecting the current flowing through the busbar 12. A plurality of current detection units are dispersedly arranged at one end side and the other end side in the long side direction of the busbar 12. An example of dispersed arrangement is described below.

[0029] The circuit breaker control circuit 20 is connected to the active fuse 10, and cuts off the bus bar 12 by controlling the active fuse 10. Specifically, the circuit breaker control circuit 20 outputs an ignition signal S3 to the active fuse 10 based on the detection signal S1 output from the current detection unit 13a and the detection signal S2 output from the current detection unit 13b. If the ignition signal S3 is input, the cutter 11 cuts off the bus bar 12. The circuit breaker control circuit 20 is implemented by, for example, a microcontroller unit (MCU: Micro Controller Unit). The circuit breaker control circuit 20 includes a detection signal acquisition unit 21, a circuit breaker determination unit 22, a comparison unit 23, and an ignition control circuit 24.

[0030] The detection signal acquisition unit 21 acquires the detection signal S1 output from the current detection unit 13a and the detection signal S2 output from the current detection unit 13b. For example, the detection signal S1 is a signal indicating a voltage generated when current flows through the resistor 131a of the current detection unit 13a, and the detection signal S2 is a signal indicating a voltage generated when current flows through the resistor 131b of the current detection unit 13b.

[0031] The disconnection determination unit 22 determines whether to disconnect the path connecting the battery and the load based on the detection signals S1 and S2 output from the current detection units 13a and 13b. For example, the disconnection determination unit 22 first divides the sum of the voltage indicated by the detection signal S1 output from the current detection unit 13a and the voltage indicated by the detection signal S2 output from the current detection unit 13b by the sum of the resistance value of the resistor 131a and the resistance value of the resistor 131b, thereby calculating the current value flowing through the bus bar 12. Next, when the calculated current value flowing through the bus bar 12 is greater than a specified value, that is, when a large current flows through the bus bar 12, it is determined that the above path is disconnected.

[0032] The comparison unit 23 compares the current value calculated based on the detection signal S1 with the current value calculated based on the detection signal S2. Specifically, the comparison unit 23 divides the voltage shown by the detection signal S1 by the resistance value of the resistor 131a, and further divides the voltage shown by the detection signal S2 by the resistance value of the resistor 131b, thereby calculating multiple current values. The comparison unit 23 performs fault detection of the current detection units 13a and 13b based on the comparison results of the multiple current values. When the multiple current values ​​are different, it is determined that any one of the current detection unit 13a or the current detection unit 13b has a fault. For example, when any one of the multiple current detection units has a fault, the circuit breaker control circuit 20 can notify the external device of the situation.

[0033] When determining to disconnect the path connecting the battery and the load, the ignition control circuit 24 outputs an ignition signal S3 to the active fuse 10. Thus, when a large current due to a short circuit abnormality flows in the path, the active fuse 10 can cut off the bus bar 12 to cut off the path.

[0034] There are various embodiments of the DC short-circuit protection device 1 , and the first to fifth embodiments are described below.

[0035] (first example)

[0036] First, use Figure 2 and Figure 3 A first example of the DC short-circuit protection device 1 will be described.

[0037] Figure 21 is a perspective view of the active fuse 10 in the first example.

[0038] Figure 3 FIG. 1 is a partial cross-sectional view of the active fuse 10 in the first example. Figure 3 In FIG. 1 , the cross-section of the cutting machine 11 is omitted.

[0039] The cutting machine 11 includes, for example, an ignition terminal 11a and a cutting blade 11b. The ignition terminal 11a is connected to an ignition control circuit 24 of the circuit breaker control circuit 20. When an ignition signal S3 (see Figure 1 ), the cutting machine 11 instantly presses the cutting blade 11b downward to cut the bus bar 12.

[0040] For example, the bus bar 12 is provided with a fastening portion 12a at one end in the long-side direction of the bus bar 12, and a fastening portion 12b is provided at the other end in the long-side direction of the bus bar 12. The bus bar 12 is inserted in the middle of the path connecting the battery and the load, and the fastening portions 12a and 12b are fastened to the path by screws or the like. Thus, the bus bar 12 becomes a part of the above-mentioned path. The cut portion 121 of the bus bar 12 is a portion cut by the cutting blade 11b of the cutter 11 when the ignition signal S3 is output from the circuit breaker control circuit 20.

[0041] In the first example, the plurality of current detection parts are dispersedly arranged at one end side (e.g., the fastening part 12a side) and the other end side (e.g., the fastening part 12b side) in the long-side direction of the bus bar 12 with respect to the cut-off part 121 of the bus bar 12 cut by the active fuse 10. In addition, in the first example, there are two current detection parts, one current detection part 13a of the two current detection parts is arranged at one end side in the long-side direction of the bus bar 12 with respect to the cut-off part 121, and the other current detection part 13b is arranged at the other end side in the long-side direction of the bus bar 12 with respect to the cut-off part 121.

[0042] The current detection unit 13a includes a resistor 131a, and the current detection unit 13b includes a resistor 131b. For example, the resistance value of the resistor 131a is the same as the resistance value of the resistor 131b. The resistors 131a and 131b are each a resistor element (shunt resistor) of about tens of micro-ohms. Figure 2 and Figure 3As shown, the resistors 131a and 131b are integrated with the bus bar 12 by being inserted into the bus bar 12. In addition, in the fourth and fifth examples described later, examples are described in which the resistors 131a and 131b are not resistor elements but are parts of the bus bar 12, and are integrated with the bus bar 12 as parts of the bus bar 12. By converting the current flowing through the bus bar 12 into a voltage at the resistors 131a and 131b integrated with the bus bar 12, the current flowing through the bus bar 12 can be detected.

[0043] For example, each of the plurality of current detection units has two current monitoring terminals for monitoring the current flowing through the resistor unit. In the first example, the current detection unit 13a has current monitoring terminals 132a and 133a for monitoring the current flowing through the resistor unit 131a, and the current monitoring terminals 132a and 133a are provided on the bus bar 12 in such a manner that the resistor unit 131a is located between the current monitoring terminals 132a and 133a. In addition, the current detection unit 13b has current monitoring terminals 132b and 133b for monitoring the current flowing through the resistor unit 131b, and the current monitoring terminals 132b and 133b are provided on the bus bar 12 in such a manner that the resistor unit 131b is located between the current monitoring terminals 132b and 133b. For example, the distance between the current monitoring terminals 132a and 133a is substantially the same as the distance between the current monitoring terminals 132b and 133b.

[0044] The current monitoring terminals 132a, 133a, 132b, and 133b are connected to the detection signal acquisition unit 21 of the circuit breaker control circuit 20. The detection signal acquisition unit 21 acquires the voltage between the current monitoring terminals 132a and 133a and the voltage between the current monitoring terminals 132b and 133b as detection signals, respectively. The voltage between the current monitoring terminals 132a and 133a is the voltage generated in the resistor 131a due to the current flowing through the resistor 131a, and the voltage between the current monitoring terminals 132b and 133b is the voltage generated in the resistor 131b due to the current flowing through the resistor 131b.

[0045] Furthermore, in the first example, an example is shown in which the plurality of current detection units are provided outside the casing of the active fuse 10 , but at least one of the plurality of current detection units may be provided inside the casing of the active fuse 10 .

[0046] In addition, the cutting machine 11 may include a plurality of cutting blades, and when the firing signal S3 is output from the cutting control circuit 20 , the bus bar 12 may be cut at a plurality of locations.

[0047] As described above, the DC short-circuit protection device 1 includes an active fuse 10 having a bus bar 12, which responds to the ignition signal S3 (see Figure 1) to cut off the bus bar 12; the current detection part 13a has a resistor part 131a, which detects the current flowing through the bus bar 12; and the current detection part 13b has a resistor part 131b, which detects the current flowing through the bus bar 12, and the resistor parts 131a and 131b are integrated with the bus bar 12 in a manner that the current of the same magnitude as the current flowing through the bus bar 12 flows, and are cut off between the current detection part 13a and the current detection part 13b. That is, the current detection part 13a and the current detection part 13b are dispersedly arranged on the bus bar.

[0048] For example, when a single current detection unit is configured instead of a plurality of current detection units in a dispersed manner, the heat generated by the resistor unit that needs a certain resistance value to detect the current is concentrated on the resistor unit of the single current detection unit, and heat dissipation becomes difficult. On the other hand, when a plurality of current detection units are dispersedly configured, the resistance value of each resistor unit can be reduced, so the heat generated by each resistor unit can be reduced, and the heat concentration can be alleviated. Therefore, the DC short-circuit protection device 1 in which a plurality of current detection units are dispersedly configured can easily dissipate heat.

[0049] For example, the plurality of current detection parts are preferably dispersedly arranged at one end side and the other end side in the long side direction of the bus bar 12 relative to the cut-off portion 121 of the bus bar 12 cut by the active fuse 10. For example, the plurality of current detection parts may be two, one current detection part 13a of the two current detection parts is arranged at one end side in the long side direction of the bus bar 12 relative to the cut-off portion 121, and the other current detection part 13b is arranged at the other end side in the long side direction of the bus bar 12 relative to the cut-off portion 121.

[0050] For example, when there are many current detection units, it is necessary to process the detection signals of each of the multiple current detection units, which increases the processing load. In contrast, by setting the multiple current detection units to two and dispersing the two current detection units, the processing load can be reduced and heat can be easily dissipated.

[0051] For example, the DC short-circuit protection device 1 may further include a disconnection control circuit 20 that outputs a firing signal S3 to the active fuse 10 based on detection signals output from a plurality of current detection units.

[0052] In this way, the circuit breaker control circuit 20 can also be provided in the DC short-circuit protection device 1 .

[0053] For example, each of the plurality of current detection units may include a current monitoring terminal for monitoring the current flowing through the resistor unit.

[0054] In this way, the current monitoring terminal can be provided in the current detection unit.

[0055] For example, the DC short-circuit protection device 1 may further include a comparison unit 23 that compares a plurality of current values ​​based on detection signals output from the plurality of current detection units, and performs failure detection of the plurality of current detection units based on the comparison result of the plurality of current values.

[0056] Thus, the same current flows through the resistors of the multiple current detection units, and thus the multiple current values ​​based on the detection signals output from the multiple current detection units should be the same. However, when any one of the multiple current detection units fails, the current values ​​may be different. For example, when there are two current detection units, when the two current values ​​are different, it is difficult to determine which of the two current detection units has failed, but it is possible to detect that one of the two current detection units has failed.

[0057] (Second example)

[0058] Next, use Figure 4 A second example of the DC short-circuit protection device 1 will be described.

[0059] Figure 4 It is a perspective view of the active fuse 10 in the second example.

[0060] In the second example, the bus bar 12 is provided with a temperature monitoring terminal 140 for monitoring the temperature of the bus bar 12. Other points are the same as those of the first example, and thus description thereof is omitted.

[0061] The temperature monitoring terminal 140 is connected to a thermistor or a thermocouple to monitor the temperature of the bus bar 12. The temperature of the bus bar 12 is acquired by the disconnection control circuit 20 and used by the disconnection determination unit 22 to calculate the current value of the current flowing through the bus bar 12.

[0062] The resistance value of the resistor portion of the plurality of current detection portions changes according to the temperature, and accordingly, the voltage generated in the resistor portion changes. Therefore, the calculation result of the current flowing through the bus bar 12 changes according to the temperature. Therefore, by monitoring the temperature of the bus bar 12 in which the resistor portion is integrated, the detection signals of the plurality of current detection portions or the calculated current values ​​are corrected according to the temperature of the bus bar 12, so that the current flowing through the bus bar 12 can be accurately detected.

[0063] (Third example)

[0064] Next, use Figure 5 A third example of the DC short-circuit protection device 1 will be described.

[0065] Figure 5 FIG. 1 is a partial cross-sectional view of the active fuse 10 in the third example. Figure 5 In FIG. 1 , the cross-section of the cutting machine 11 is omitted. Figure 5In the figure, the current monitoring terminal is omitted.

[0066] In the third example, there are three current detection units, and two current detection units 13a and 13c (resistance units 131a and 131c) of the three current detection units 13a to 13c are arranged at one end side in the long-side direction of the bus bar 12 relative to the cut portion 121, and the remaining current detection unit 13b (resistance unit 131b) of the three current detection units 13a to 13c is arranged at the other end side in the long-side direction of the bus bar 12 relative to the cut portion 121. Other points are the same as those in the first example, so the description is omitted.

[0067] In the third example, by setting the number of current detection units to three, a faulty current detection unit among the multiple current detection units can be identified. Specifically, when the current value based on the detection signal output from one of the three current detection units 13a to 13c is different from the two current values ​​based on the detection signals output from the other two current detection units, it can be detected that the one current detection unit has a fault.

[0068] exist Figure 5 In the figure, an example is shown in which the current detection unit 13c is arranged in the frame of the active fuse 10, but two or more of the three current detection units 13a~13c may be arranged in the frame of the active fuse 10, or all of the three current detection units 13a~13c may be arranged outside the frame of the active fuse 10.

[0069] Furthermore, in the third example, the bus bar 12 may be provided with a temperature monitoring terminal 140 .

[0070] (Fourth example)

[0071] Next, use Figures 6 to 8 A fourth example of the DC short-circuit protection device 1 will be described.

[0072] Figure 6 FIG. 1 is a partial cross-sectional view of the active fuse 10 in the fourth example. Figure 6 In FIG. 1 , the cross-section of the cutting machine 11 is omitted.

[0073] Figure 7 It is a bottom view of the bus bar 12 in the fourth example.

[0074] Figure 8 1 is a diagram for explaining the cross-sectional structure of the bus bar 12 in the fourth example. Figure 8 In the figure, the current monitoring terminal is omitted.

[0075] In the fourth example, the resistors of the multiple current detection units (the resistors 131a and 131b of the two current detection units in the fourth example) are part of the bus bar 12, and the part with increased resistance value is used as the resistor by making a part of the bus bar 12 thinner or thinner. Specifically, the area of ​​the cross section of the resistor of the bus bar 12 perpendicular to the direction of current flow is smaller than the area of ​​the cross section of the part other than the resistor of the bus bar 12 perpendicular to the direction of current flow. Figure 7 and Figure 8 As shown, it can be seen that the cross-sectional area of ​​the resistor portion 131a ( Figure 8 The area of ​​the cross section BB′ of FIG. 1 is smaller than the area of ​​the cross section of the portion other than the resistor portions 131a and 131b (for example, Figure 8 By connecting current monitoring terminals at both ends of the portion where the cross-sectional area decreases, the voltage generated by the current flowing through the portion can be obtained through the current monitoring terminals, so that the portion can be used as a current detection unit.

[0076] In the fourth example, the active fuse 10 cuts the bus bar 12 at two locations, one end and the other end in the long-side direction of the bus bar 12. For example, the cutter 11 of the active fuse 10 has two cutting blades 11c and 11d. When the ignition control circuit 24 outputs the ignition signal S3 to the ignition terminal 11a, the cutter 11 moves the cutting blades 11c and 11d toward the ignition terminal 11a. Figure 6 The current detecting section 13a of one of the plurality of current detecting sections is momentarily pressed downward to cut off the bus bar 12. In addition, the resistor section 131a of one of the plurality of current detecting sections 13a is a cut portion on one end side of the long side direction of the bus bar 12 cut by the active fuse 10, and the resistor section 131b of another of the plurality of current detecting sections 13b is a cut portion on the other end side of the long side direction of the bus bar 12 cut by the active fuse 10. That is, the resistor section 131a is a cut portion on one end side of the long side direction of the bus bar 12 cut by the cutting blade 11c of the cutter 11 when the ignition signal S3 is output from the circuit breaker control circuit 20, and the resistor section 131b is a cut portion on the other end side of the long side direction of the bus bar 12 cut by the cutting blade 11d of the cutter 11 when the ignition signal S3 is output from the circuit breaker control circuit 20.

[0077] The cross-sectional area of ​​the cut-off portion of the bus bar 12 cut by the active fuse 10 is smaller (e.g., contracted) than other portions of the bus bar 12 to facilitate cutting. Therefore, the resistance value of the cut-off portion of the bus bar 12 is higher than that of other portions of the bus bar 12. Therefore, the cut-off portion can be used as a resistor for detecting the current flowing through the bus bar 12, and the structure of the DC short-circuit protection device 1 can be simplified and the cost can be reduced compared to the case where a resistor for detecting the current flowing through the bus bar 12 is separately prepared.

[0078] Furthermore, when the cut portion of the bus bar 12 is treated as a resistor, the resistance value varies due to the dimensional tolerance caused by the processing accuracy of the cut portion. Therefore, the calibration value of each individual can be stored in a flash memory of the disconnection control circuit 20, and the current value of each individual can be corrected using the calibration value.

[0079] In the fourth example, the number of the plurality of current detection units may be three or more. In addition, the plurality of current detection units may include a current detection unit in which the resistance unit is a part of the bus bar 12 and a current detection unit in which the resistance unit is a resistor element.

[0080] In the fourth example, the cut portion of the bus bar 12 is used as the resistor of the current detection section. However, a portion that is not a cut portion and has a small cross-sectional area may be used as the resistor of the current detection section.

[0081] Furthermore, in the fourth example, the bus bar 12 may be provided with a temperature monitoring terminal 140 .

[0082] (Fifth Example)

[0083] Next, use Fig. 9 A fifth example of the DC short-circuit protection device 1 will be described.

[0084] Fig. 9 is a top view of the bus bar 12 in the fifth example. Fig. 9 In the figure, the current monitoring terminal is omitted.

[0085] In the fifth example, the shape of the resistor portion (cut portion) of the bus bar is different from that of the fourth example. Other points are the same as those of the fourth example, and thus description thereof is omitted.

[0086] When the cut portion of the bus bar 12 is treated as a resistor, the resistance value of the resistor varies due to the dimensional tolerance of the cut portion. Fig. 9 As shown, the resistor portion (cut-off portion) is formed to have a constant cross-sectional shape and a thickness of several millimeters along the direction of current flow, thereby enabling stable current detection even if there is variation in resistance value due to processing accuracy.

[0087] (Other embodiments)

[0088] As described above, the embodiments have been described as examples of the technology of the present disclosure. However, the technology of the present disclosure is not limited thereto, and can also be applied to embodiments that are appropriately changed, replaced, added, omitted, etc. For example, the following modified examples are also included in one embodiment of the present disclosure.

[0089] For example, in the above embodiment, the DC short-circuit protection device 1 (specifically, the disconnection control circuit 20 ) includes the comparison unit 23 , but the DC short-circuit protection device 1 may not include the comparison unit 23 .

[0090] For example, in the above embodiment, the DC short-circuit protection device 1 includes the disconnection control circuit 20, but the disconnection control circuit 20 may not be provided in the DC short-circuit protection device 1. That is, the disconnection control circuit 20 may be provided separately from the DC short-circuit protection device 1.

[0091] For example, in the above-mentioned embodiment, an example is described in which each of the plurality of current detection units has a current monitoring terminal, but the current monitoring terminal may not be a component element of the current detection unit.

[0092] In addition, various modifications that can be conceived by those skilled in the art to the embodiments and arbitrarily combining components and functions in the embodiments within the scope not departing from the gist of the present disclosure are also included in the present disclosure.

[0093] (Summarize)

[0094] The first mode of the DC short-circuit protection device 1 disclosed in the present invention comprises: an active fuse 10, having a bus bar 12, which cuts off the bus bar 12 in response to an ignition signal S3; a current detection unit 13a, having a resistor unit 131a, which detects the current flowing through the bus bar 12; and a current detection unit 13b, having a resistor unit 131b, which detects the current flowing through the bus bar 12, the resistor unit 131a and the resistor unit 131b are integrated with the bus bar 12 in such a way that a current of the same magnitude as the current flowing through the bus bar 12 flows, and the bus bar 12 is cut off between the current detection unit 13a and the current detection unit 13b in response to the ignition signal S3, or the resistor unit 131a of the current detection unit 13a is cut off.

[0095] According to the above configuration, since the bus bar 12 is provided with a plurality of current detection portions, the resistance value of each resistor portion can be reduced, and heat can be easily dissipated.

[0096] In the DC short-circuit protection device 1 of the second embodiment of the present disclosure, the resistor portion 131a and the resistor portion 131b are part of the bus bar 12, and the direction of the current flowing through the resistor portion 131a and the bus bar 12 is set to a first direction (a left-right direction in this embodiment), and the area of ​​the cross section of the resistor portion 131a orthogonal to the first direction (for example Figure 8 The area of ​​the cross section taken along the line BB′ shown in FIG. 1 ) and the area of ​​the cross section of the resistor portion 131 b perpendicular to the first direction (eg Figure 8 The area of ​​the cross section DD′ shown in FIG. 1 is smaller than the cross section area of ​​the portion other than the resistor portion 131a and the resistor portion 131b in the bus bar 12 perpendicular to the first direction (for example, Figure 8 The area of ​​the AA′ section is shown).

[0097] According to the above configuration, current monitoring terminals are connected to both ends of the portion where the cross-sectional area is reduced, and a voltage generated by current flowing through the portion can be obtained through the current monitoring terminals. Therefore, the portion can be used as a current detection unit.

[0098] In the third type of DC short-circuit protection device 1 of the present disclosure, the bus bar 12 has a cut-off portion 121 cut off by the active fuse 10, the current detection unit 13a is located between one end of the bus bar 12 and the cut-off portion 121, and the current detection unit 13b is located between the other end of the bus bar 12 and the cut-off portion 121.

[0099] According to the above configuration, by distributing the two current detection units, it is possible to reduce the processing load and to easily dissipate heat.

[0100] The DC short-circuit protection device 1 according to the fourth aspect of the present disclosure further includes a current detection unit 13 c , and the current detection unit 13 c is located between one end of the bus bar 12 and the cut-off portion 121 .

[0101] According to the above configuration, when the current value based on the detection signal outputted from one of the three current detection units 13a to 13c is different from the two current values ​​based on the detection signals outputted from the other two current detection units, it can be detected that the one current detection unit has failed.

[0102] In the DC short-circuit protection device 1 of the fifth aspect of the present disclosure, the active fuse 10 cuts off the resistor 131 a of the current detection unit 13 a (or the resistor 131 b of the current detection unit 13 b ) in response to the ignition signal S3 .

[0103] According to the above structure, the resistor portion 131 a (or the resistor portion 131 b ) can be used as the cut-off portion 121 .

[0104] The DC short-circuit protection device 1 of the sixth aspect of the present disclosure further includes a disconnection control circuit 20 that outputs a firing signal S3 to the active fuse 10 based on the detection signal S1 output from the current detection unit 13 a and the detection signal S2 output from the current detection unit 13 b .

[0105] According to the above configuration, the bus bar 12 can be disconnected based on the detection signals S1 and S2 output from the current detection units 13 a and 13 b.

[0106] In the DC short-circuit protection device 1 of the seventh aspect of the present disclosure, the current detection unit 13a has current monitoring terminals 132a and 133a for monitoring the current flowing through the resistor 131a, and the current detection unit 13b has second current monitoring terminals 132b and 133b for monitoring the current flowing through the resistor 131b.

[0107] According to the above configuration, the voltage generated in the resistor portion 131 a and the resistor portion 131 b can be output from the current detection portions 13 a and 13 b as the detection signals S1 and S2 .

[0108] The DC short-circuit protection device 1 according to the eighth aspect of the present disclosure further includes a temperature monitoring terminal 140 . The temperature monitoring terminal 140 is provided on the bus bar 12 and monitors the temperature of the bus bar 12 .

[0109] According to the above configuration, the temperature of the bus bar 12 can be monitored, and the temperature of the bus bar 12 can be used for calculation of the current value.

[0110] The DC short-circuit protection device 1 of the ninth aspect of the present disclosure further includes a comparison unit 23 that compares a first current value calculated based on the detection signal S1 output from the current detection unit 13a and a second current value calculated based on the detection signal S2 output from the current detection unit 13b.

[0111] According to the above configuration, when the first current value and the second current value are different, it can be determined that either the current detection unit 13 a or the current detection unit 13 b has failed.

[0112] Industrial Applicability

[0113] The present disclosure can be applied to a device for interrupting a current flowing through a current path.

[0114] Description of symbols

[0115] 1 DC short circuit protection device

[0116] 10 Active fuse

[0117] 11 Cutting machine

[0118] 11a Ignition terminal

[0119] 11b, 11c, 11d cutting edges

[0120] 12 Bus Bar

[0121] 12a, 12b fastening portion

[0122] 13a, 13b, 13c current detection unit

[0123] 20 Breaker control circuit

[0124] 21 Detection signal acquisition unit

[0125] 22 Breaking judgment unit

[0126] 23 Comparative Department

[0127] 24 Ignition control circuit

[0128] 121 Cut off part

[0129] 131a, 131b, 131c resistors

[0130] 132a, 133a, 132b, 133b Current monitoring terminals

[0131] 140 Temperature monitoring terminal

[0132] S1, S2 detection signal

[0133] S3 ignition signal

Claims

1. A DC short-circuit protection device, comprising: a fuse having a bus bar, the bus bar being cut in response to an ignition signal; a first current detection unit having a first resistor unit for detecting a current flowing through the bus bar; as well as The second current detection unit has a second resistor unit and detects the current flowing through the bus bar. The first resistor portion and the second resistor portion are integrated with the bus bar in such a manner that a current having the same magnitude as a current flowing through the bus bar flows therethrough. In response to the ignition signal, the bus bar is cut between the first current detection unit and the second current detection unit, or the first resistor unit of the first current detection unit is cut off.

2. The DC short circuit protection device according to claim 1, wherein: The first resistor portion and the second resistor portion are part of the bus bar, The direction of the current flowing through the first resistor portion, the second resistor portion, and the bus bar is defined as a first direction, The cross-sectional area of ​​the first resistor portion and the cross-sectional area of ​​the second resistor portion perpendicular to the first direction are smaller than the cross-sectional area of ​​the bus bar other than the first resistor portion and the second resistor portion perpendicular to the first direction.

3. The DC short circuit protection device according to claim 1 or 2, wherein: The bus bar has a cut-off portion cut off by the fuse, The first current detection unit is located between one end of the bus bar and the cut-off portion. The second current detection section is located between the other end of the bus bar and the cut-off portion.

4. The DC short circuit protection device according to claim 3, wherein: The DC short-circuit protection device further includes a third current detection unit located between the one end of the bus bar and the cut-off portion.

5. The DC short circuit protection device according to claim 2, wherein: The fuse cuts off the first resistance section of the first current detection section in response to the ignition signal.

6. The DC short-circuit protection device according to any one of claims 1 to 5, wherein: The DC short-circuit protection device further includes a disconnection control circuit that outputs the ignition signal to the fuse based on the signal output from the first current detection unit and the signal output from the second current detection unit.

7. The DC short-circuit protection device according to any one of claims 1 to 6, wherein: The first current detection unit has a first current monitoring terminal for monitoring the current flowing through the first resistor unit. The second current detection unit includes a second current monitoring terminal for monitoring a current flowing through the second resistance unit.

8. The DC short-circuit protection device according to any one of claims 1 to 7, wherein: The DC short-circuit protection device further includes a temperature monitoring terminal, which is provided on the bus bar and monitors the temperature of the bus bar.

9. The DC short-circuit protection device according to any one of claims 1 to 8, wherein: The DC short-circuit protection device further includes a comparison unit that compares a first current value calculated based on a first detection signal output from the first current detection unit and a second current value calculated based on a second signal output from the second current detection unit.

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