Current interruption device
The current interruption device addresses battery consumption by employing a Hall element and capacitor-based control system to detect and interrupt current, ensuring efficient power management and extended vehicle range.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- YAZAKI CORP
- Filing Date
- 2023-11-15
- Publication Date
- 2026-06-09
AI Technical Summary
Existing current interruption devices consume significant battery power due to the constant flow of current through shunt resistors for measurement, leading to inefficient energy usage.
A current interruption device utilizing a Hall element to detect current values, an interruption unit, and an interruption control unit with a voltage-to-current conversion unit, capacitor, and an interruption signal output unit to manage power line interruptions based on capacitor voltage thresholds, reducing battery consumption.
The device effectively interrupts current while minimizing battery consumption, enhancing energy efficiency and extending vehicle driving range by using a Hall element to detect current without drawing power from the battery.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a current interruption device.
Background Art
[0002] Conventionally, as for a current interruption device, for example, as described in Patent Document 1, a current interruption system for interrupting the current flowing from a battery to a load is known. This current interruption system includes a shunt resistor that measures the current value flowing from the battery to the load, and when the current value measured by the shunt resistor exceeds a preset threshold value, the base material between the battery and the load is cut to interrupt the current and protect the battery.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the above-described system, there is room for improvement in that the consumption of the battery is large. That is, in the above-described system, it is necessary to constantly flow a current through the shunt resistor to measure the current value, and the consumption of the battery becomes large.
[0005] Therefore, an object of the present invention is to provide a current interruption device that can suppress the consumption of the battery and appropriately interrupt the current.
Means for Solving the Problems
[0006] In other words, the current interruption device according to the present invention comprises a Hall element for detecting the current value of a power line supplying power from a battery to a load, an interruption unit for interrupting the power line, and an interruption control unit that activates the interruption unit based on the detection signal of the Hall element to interrupt the power line, wherein the interruption control unit is configured to include a voltage-to-current conversion unit that outputs a current corresponding to the output voltage value of the Hall element, a capacitor that is charged according to the output current of the voltage-to-current conversion unit, and an interruption signal output unit that outputs an interruption signal to the interruption unit when the voltage of the capacitor exceeds a threshold. [Effects of the Invention]
[0007] The current interruption device according to the present invention can appropriately interrupt the current while suppressing battery consumption. [Brief explanation of the drawing]
[0008] [Figure 1] Figure 1 is a circuit diagram showing the general configuration of the current interruption device according to the first embodiment. [Figure 2] Figure 2 is a timing chart showing the operation of the current interruption device according to the first embodiment. [Figure 3] Figure 3 is a circuit diagram showing the general configuration of the current interruption device according to the second embodiment. [Figure 4] Figure 4 is a timing chart showing the operation of the current interruption device according to the second embodiment. [Figure 5] Figure 5 is a circuit diagram showing the general configuration of the current interruption device according to the third embodiment. [Figure 6] Figure 6 is a timing chart showing the operation of the current interruption device according to the third embodiment. [Modes for carrying out the invention]
[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments. Furthermore, some of the components in the following embodiments may be easily substituted or substantially identical to those that are easily substituted by those skilled in the art.
[0010] [Embodiment] This embodiment relates to a current interruption device. As shown in Figure 1, the current interruption device 1 according to the first embodiment is a device that interrupts a power line 13 that supplies power from a battery 11 to a motor 12, and is used in electric vehicles or hybrid vehicles that use the motor 12 as a driving source. The current interruption device 1, for example, detects an overcurrent or short circuit in the power line 13 connected to a high-voltage battery 11, and interrupts the power line 13 when such an overcurrent or short circuit is detected.
[0011] The battery 11 and the motor 12 are connected by a power line 13. The battery 11 is a battery that outputs enough power to drive the motor 12. The motor 12 is a load that operates by receiving power from the battery 11. The power line 13 is a transmission line for supplying power from the battery 11 to the motor 12, and is used, for example, an insulated wire with a conductor covered with an insulator. The power line 13 is provided with a cut-off section 14 and a relay 15. The cut-off section 14 is a component that interrupts the current in the power line 13 when it is cut, and is used, for example, a busbar. The cut-off section 14 is cut when the power line 13 is short-circuited or when an overcurrent exceeding a predetermined current value flows through the power line 13. The relay 15 is a main relay for turning the power supply to the motor 12 on and off.
[0012] The current interruption device 1 comprises a Hall element 2, an interruption unit 3, and an interruption control unit 4. The Hall element 2 is a current detection unit that detects the current value flowing through the power line 13. For example, the Hall element 2 detects the current value flowing through the power line 13 by receiving the current from the constant current source 21 and detecting the magnetic field formed around the power line 13. Since the Hall element 2 can be used without drawing current from the battery 11, like a shunt resistor, it can suppress the power consumption of the battery 11.
[0013] The shut-off unit 3 is a unit that shuts off the power line 13. For example, it operates in response to a shut-off signal from the shut-off control unit 4, and cuts the part to be cut 14 to shut off the power line 13. The shut-off unit 3 includes, for example, an ignition unit 31, a gunpowder storage unit 32, and a cutting unit 33. The ignition unit 31 is a component that receives a shut-off signal and ignites the gunpowder stored in the gunpowder storage unit 32. For example, the ignition unit 31 receives a shut-off signal via a switching element or the like and ignites the gunpowder stored in the gunpowder storage unit 32. The gunpowder storage unit 32 is a storage unit that houses the gunpowder. The cutting unit 33 is a component that cuts the part to be cut 14 to shut off the power line 13. For example, it operates due to the explosive force from the ignition of the gunpowder, and contacts the part to be cut 14 to cut it.
[0014] The interruption control unit 4 is an interruption control unit that activates the interruption unit 3 based on the detection signal from the Hall element 2 to interrupt the power line 13, and is composed of, for example, an interruption control circuit. The interruption control unit 4 has a voltage-to-current conversion unit 41, a capacitor 42, and an interruption signal output unit 43.
[0015] The voltage-current conversion unit 41 is a voltage-current conversion circuit that outputs a current corresponding to the output voltage value of the Hall element 2. For example, the voltage-current conversion unit 41 is connected to the output side of the Hall element 2 via an amplification circuit 44. The amplification circuit 44 is a circuit that amplifies the detection signal of the Hall element 2. The voltage-current conversion unit 41 receives the voltage amplified by the amplification circuit 44 as input to the detection signal of the Hall element 2, converts the amplified voltage into a current, and outputs it. The voltage-current conversion unit 41 is configured, for example, using a differential amplifier, with a transistor 45 connected to the output side of the differential amplifier.
[0016] The capacitor 42 is a capacitor that is charged according to the output of the Hall element 2. For example, the capacitor 42 is connected to the output side of the voltage-current conversion unit 41 via a first current mirror circuit 46. The first current mirror circuit 46 is a circuit that outputs a current having the same current value as the current output from the voltage-current conversion unit 41. For example, the capacitor 42 is charged by a current having the same current value as the output current of the voltage-current conversion unit 41 via the first current mirror circuit 46. The capacitor 42 is charged faster as the current output from the voltage-current conversion unit 41 is larger, and the charging voltage becomes larger as the output current of the voltage-current conversion unit 41 is continuously output for a longer time.
[0017] Also, a constant current is discharged from the capacitor 42 by the constant current circuit 47. For example, the capacitor 42 is connected to the output side of the constant current circuit 47 via a second current mirror circuit 48. Therefore, the capacitor 42 is discharged by a current having the same current value as the output current of the constant current circuit 47 via the second current mirror circuit 48. As a result, the voltage value of the capacitor 42 does not increase when a current larger than the output current of the constant current circuit 47 is not charged.
[0018] The voltage Vc of the capacitor 42 is input to the cutoff signal output unit 43. The cutoff signal output unit 43 is an output circuit that outputs a cutoff signal to the cutoff unit 3 when the voltage Vc of the capacitor 42 exceeds the threshold value Vref. For example, a comparator is used as the cutoff signal output unit 43. The threshold value Vref is, for example, a voltage set by the constant voltage circuit 49. The cutoff signal output unit 43 outputs a cutoff signal to the switching element 34 of the cutoff unit 3 when the voltage Vc of the capacitor 42 exceeds the threshold value Vref, and activates the ignition unit 31.
[0019] Next, the operation of the current cutoff device 1 according to the first embodiment will be described.
[0020] FIG. 2 is a timing chart showing the operation of the current interruption device 1. The horizontal axis represents time, and the vertical axis represents the current I in the power line 13, the voltage Vc of the capacitor 42, and the output signal Vcmp of the interruption signal output unit 43. The 100% value shown in FIG. 2 is the current value of the current I that charges the capacitor 42. That is, when the current I in the power line 13 exceeds the 100% value, the capacitor 42 starts to be charged.
[0021] In FIG. 2, when the current I flowing through the power line 13 is an overcurrent exceeding the 100% value, as shown in the time t1 - t2, the voltage Vc of the capacitor 42 rises. That is, in FIG. 1, a detection signal is output from the Hall element 2, the detection signal is amplified by the amplifier circuit 44, and is converted into a current by the voltage - current conversion unit 41. Then, a current having the same current value as the output current of the voltage - current conversion unit 41 is output from the first current mirror circuit 46 and charges the capacitor 42. At this time, the capacitor 42 is discharged at the same current value as the output current of the constant - current circuit 47. Therefore, when the charging current of the capacitor 42 becomes larger than the discharging current, the voltage Vc of the capacitor 42 starts to rise (time t1).
[0022] However, if the current I in the power line 13 becomes small before the voltage Vc of the capacitor 42 reaches the threshold value Vref (time t2), the voltage Vc of the capacitor 42 drops, and the current interruption of the power line 13 is not performed. For this reason, misinterruption of the current interruption device 1 can be suppressed. For example, when a momentary overcurrent such as a surge current flows through the power line 13, when there is no problem with the battery 11 and the relay 15, the current interruption device 1 does not perform current interruption of the power line 13 and can suppress unnecessary current interruption.
[0023] And, as shown in the time t3 - t4 of FIG. 2, when the motor 12 is being driven in a steady state, no overcurrent flows through the power line 13, the capacitor 42 is not charged, and the current interruption of the power line 13 is not performed.
[0024] In response to this, at time t4 in Figure 2, an overcurrent begins to flow through the power line 13, and if the overcurrent continues to flow, the capacitor 42 is charged, and the voltage Vc of the capacitor 42 exceeds the threshold Vref (time t5). As a result, in Figure 1, the cutoff signal Vcmp is output as a high-output signal from the cutoff signal output unit 43. Therefore, the ignition unit 31 is activated and the gunpowder is ignited, the cutting unit 33 is activated and the part to be cut 14 is cut. Then the power line 13 is cut and shut off, protecting the battery 11 and relay 15 from overcurrent.
[0025] The time from when an overcurrent flows through the power line 13 until the current is interrupted can be set according to the capacitance of the capacitor 42. Therefore, the capacitance of the capacitor 42 should be set according to the allowable current of the battery 11 and the relay 15. Also, the time from when an overcurrent flows through the power line 13 until the current is interrupted can be set according to the current value of the constant current circuit 47. Therefore, the current value of the constant current circuit 47 should be set according to the allowable current of the battery 11 and the relay 15.
[0026] As described above, the current interruption device 1 according to the first embodiment can interrupt the current while suppressing the consumption of the battery 11 by using a Hall element 2 to detect the current value of the power line 13. Furthermore, the current interruption device 1 according to this embodiment charges the capacitor 42 when the current I of the power line 13 exceeds a predetermined current value, and interrupts the power line 13 when the voltage Vc of the capacitor 42 exceeds a threshold Vref. Therefore, the current interruption device 1 according to this embodiment can suppress the interruption of the power line 13 due to instantaneous overcurrent. Accordingly, the current interruption device 1 according to this embodiment can appropriately interrupt the current I of the power line 13 while suppressing the consumption of the battery 11.
[0027] Furthermore, the current interruption device 1 according to this embodiment can interrupt the current while suppressing the consumption of the battery 11 by using a Hall element 2 to detect the current value of the power line 13, thus extending the driving range of the vehicle when it is installed in a vehicle.
[0028] Furthermore, the current interruption device 1 according to this embodiment includes a constant current circuit 47 that discharges a constant current from the capacitor 42, thereby suppressing instantaneous charging of the capacitor 42 due to instantaneous overcurrent. For this reason, the current interruption device 1 according to this embodiment can appropriately interrupt the current I of the power line 13 as needed.
[0029] Next, the current interruption device 1A according to the second embodiment will be described.
[0030] Figure 3 is a circuit diagram showing the configuration overview of the current interruption device 1A according to the second embodiment. The current interruption device 1A according to this embodiment differs from the current interruption device 1 according to the first embodiment in that it is further equipped with a second interruption signal output unit 50.
[0031] The second cutoff signal output unit 50 is a circuit that outputs a cutoff signal Vcmp2 to the cutoff unit 3 without waiting for the voltage Vc of capacitor 42 to exceed the threshold Vref when a large current flows through the power line 13. For example, a comparator is used as the second cutoff signal output unit 50, and the output signal of the amplification circuit 44 and the output signal of the second constant voltage circuit 51 are input to it. The second constant voltage circuit 51 sets the threshold Vref2. Therefore, when the detection signal of the Hall element 2 is amplified and exceeds the threshold Vref2, even if the voltage Vc of capacitor 42 has not exceeded the threshold Vref, the second cutoff signal output unit 50 outputs a cutoff signal Vcmp2 to the switching element 35 of the cutoff unit 3, and the current I of the power line 13 is cut off. That is, as shown in Figure 4, when a large current flows through the power line 13 and the output of the amplification circuit 44 exceeds the threshold Vref2 (time t7), the current I of the power line 13 is cut off instantaneously.
[0032] Thus, the current interruption device 1A according to this embodiment can quickly interrupt the current when a large current that would cause problems for the battery 11 and relay 15 flows through the power line 13, while suppressing the interruption of the power line 13 due to instantaneous overcurrent. Therefore, the current interruption device 1A according to this embodiment can appropriately interrupt the current I in the power line 13 and further enhance safety.
[0033] Next, the current interruption device 1B according to the third embodiment will be described.
[0034] Figure 5 is a circuit diagram showing the configuration overview of the current interruption device 1B according to the third embodiment. The current interruption device 1B according to this embodiment differs from the current interruption device 1 according to the first embodiment in that it is further equipped with a third interruption signal output unit 52.
[0035] The third cutoff signal output unit 52 is a circuit that outputs a cutoff signal Vcmp3 to the cutoff unit 3 when a large current flows through the power line 13. For example, a comparator is used as the third cutoff signal output unit 52, and the output signal of the amplification circuit 44 and the output signal of the third constant voltage circuit 53 are input to it. The third constant voltage circuit 53 sets a threshold value Vref3. The threshold value Vref3 is set to a current value that is the same as or less than the 100% value of the current I in the power line 13.
[0036] When the detection signal from the Hall element 2 is amplified and exceeds the threshold Vref3, the third cutoff signal output unit 52 outputs a cutoff signal Vcmp3 as a low output signal to the switching element 36 of the cutoff unit 3. The switching element 36 is located between the ignition unit 31 and the power supply VB, and the ignition unit 31 becomes activatable when the cutoff signal Vcmp3 is output as a low signal. Then, when the ignition unit 31 is activatable, if the voltage Vc of the capacitor 42 exceeds the threshold Vref due to an overcurrent in the power supply line 13, the ignition unit 31 activates and the current I of the power supply line 13 is cut off. That is, as shown at time t9 in Figure 6, when the cutoff signal Vcmp3 is output as a low signal and the voltage Vc of the capacitor 42 exceeds the threshold Vref, the current I of the power supply line 13 is cut off instantaneously.
[0037] Thus, the current interruption device 1B according to this embodiment instantly interrupts the current I of the power supply line 13 when the interruption signal Vcmp3 is output as a low signal and the voltage Vc of the capacitor 42 exceeds the threshold Vref. This prevents the current I of the power supply line 13 from being erroneously interrupted when the voltage Vc of the capacitor 42 unintentionally exceeds the threshold Vref due to noise or other reasons, even when the current I of the power supply line 13 is not an overcurrent.
[0038] It should be noted that the current interruption device according to the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. The current interruption device according to each embodiment may be constructed by appropriately combining the components of the embodiments and modified examples described above.
[0039] For example, in the second and third embodiments, the second cutoff signal output unit 50 and the third cutoff signal output unit 52 share the cutoff signal output unit 43 with the Hall element 2 and the amplification circuit 44. However, a separate Hall element and amplification circuit may be provided for the second cutoff signal output unit 50 and the third cutoff signal output unit 52, in addition to the Hall element 2 and the amplification circuit 44.
[0040] Furthermore, in each of the embodiments described above, the cutoff control unit 4 in Figures 1, 3, and 5 may be an integrated circuit configured on the same silicon substrate, and the Hall element 2 may be provided on the silicon substrate. In addition, the Hall element 2 may be fitted with a component such as a magnetic core to guide the magnetic field of the current I and to keep away external magnetic fields that cause errors.
[0041] Furthermore, although the above-described embodiments have described current interruption devices mounted on vehicles, the current interruption device according to the present invention may also be applied to devices not mounted on vehicles. [Explanation of symbols]
[0042] 1: Current interruption device 2: Hall element 3: Blocking section 4: Interruption control unit 11: Battery 12: Motor (load) 13: Power line 41: Voltage-to-current conversion section 42: Capacitor 43: Cutoff signal output section 47: Constant current circuit Vc: Voltage Vref: threshold Vcmp: Cutoff signal
Claims
1. A Hall element that detects the current value of the power line supplying power from the battery to the load, A shut-off unit that shuts off the power line, The system includes a cutoff control unit that activates the cutoff unit based on the detection signal of the Hall element to cut off the power line, The cutoff control unit includes: a voltage-current conversion unit that outputs a current corresponding to the output voltage value of the Hall element; a capacitor that is charged according to the output current of the voltage-current conversion unit; a cutoff signal output unit that outputs a cutoff signal to the cutoff unit when the voltage of the capacitor exceeds a threshold; a second cutoff signal output unit that outputs a second cutoff signal to the cutoff unit to cut off the power line even if the voltage of the capacitor does not exceed a threshold when the output voltage of the Hall element is amplified and exceeds a second threshold; and a third cutoff signal output unit that enables the cutoff unit to be activated when a current exceeding a preset current value flows through the power line, and does not activate the cutoff unit when a current exceeding the preset current value flows through the power line. The third cutoff signal output unit outputs a cutoff signal to a switching element provided between the cutoff unit and the power supply to control the activation of the cutoff unit. Current interruption device.
2. The cutoff control unit further comprises a constant current circuit that discharges a constant current from the capacitor, The current interruption device according to claim 1.