Fuse triggering circuit, power supply system and electric vehicle

Abstract

The application discloses a fuse triggering circuit, a power supply system and an electric vehicle. The circuit is provided with a power supply sampling unit, a controllable switch unit, a control power supply and an excitation fuse unit. The power supply sampling unit samples the power supply current in the power supply circuit and controls the controllable switch unit to be turned off when the power supply current is less than a current threshold value, and controls the controllable switch unit to be turned on when the power supply current is greater than or equal to the current threshold value. The excitation fuse unit is connected in series into the power supply circuit; one control end of the excitation fuse unit is connected with a first grounding end, and the other control end is connected with the control power supply through the controllable switch unit; the excitation fuse unit can trigger the fuse under the condition that the controllable switch unit is turned on, realizing short-circuit protection of the power supply circuit. The scheme utilizes the on-off and transmission of an electric signal to trigger and control the excitation fuse unit, the circuit has a simple structure and a fast response time, and the safety of the power supply circuit is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage power supply, and more particularly to a fuse triggering circuit, a power supply system, and an electric vehicle. Background Technology

[0002] In recent years, with the continuous development of energy storage battery technology, battery capacity has been greatly improved, which has led to the widespread application of energy storage batteries in many fields.

[0003] To ensure the power supply safety of large-capacity batteries, fuses are often installed in the high-voltage power supply lines of energy storage batteries to provide short-circuit protection. Existing fuse triggering circuits mostly use the battery management system to detect short circuits in the power supply circuit and control the actuators to blow the fuse based on the detection result.

[0004] However, using a battery management system for short-circuit detection and fuse control requires multiple data processing operations, including conversion, analysis, and judgment, before final control can be implemented based on the data processing results. This complex data processing and data transmission leads to an increase in the response cycle of short-circuit protection and a reduction in the safety of the power supply line. Summary of the Invention

[0005] This invention provides a fuse triggering circuit, a power supply system, and an electric vehicle to reduce fuse response time and improve the safety of high-voltage power supply lines.

[0006] According to one aspect of the present invention, a fuse triggering circuit is provided, the fuse triggering circuit comprising: a power supply sampling unit, a controllable switching unit, a control power supply, and an excitation fuse unit;

[0007] The power supply sampling unit is connected to the power supply line, and the control terminal of the controllable switch unit is connected to the power supply sampling unit. The power supply sampling unit can sample the power supply current in the power supply line, and control the controllable switch unit to open when the power supply current is less than the current threshold, and control the controllable switch unit to open when the power supply current is greater than or equal to the current threshold.

[0008] The excitation fuse unit is connected in series in the power supply line; one control terminal of the excitation fuse unit is connected to the first ground terminal, and the other control terminal is connected to the control power supply via the controllable switch unit; the excitation fuse unit can trigger a fuse when the controllable switch unit is turned on.

[0009] Optionally, the power supply sampling unit includes: a current sampling device and an isolation transformer;

[0010] The current sampling device is connected in series in the power supply line; the primary winding of the isolation transformer is connected to both ends of the current sampling device, and the secondary winding of the isolation transformer is connected between the control terminal of the controllable switch unit and the first ground terminal.

[0011] When the supply current is less than the current threshold, the voltage across the secondary winding of the isolation transformer controls the controllable switch unit to remain off, the excitation fuse unit is not triggered, and the power supply line remains on.

[0012] When the supply current is greater than or equal to the current threshold, the voltage across the secondary winding of the isolation transformer controls the controllable switch unit to conduct, and the excitation fuse unit controls the power supply line to fuse according to the connected control power supply.

[0013] Optionally, the current sampling device includes a current sampling resistor, a Hall current sensor, or a magnetoresistive current sensor.

[0014] Optionally, the excitation fuse unit further includes a fuse element and an ignition tube, the fuse element being connected in series in the power supply line; one end of the ignition tube is connected to the first ground terminal, and the other end is connected to the control power supply via the controllable switch unit; when the controllable switch unit remains on for more than a preset trigger time, the ignition tube can trigger ignition and fuse the fuse element.

[0015] Optionally, the fuse trigger circuit further includes an overvoltage protection device, which is connected to both ends of the ignition tube. The overvoltage protection device can limit the voltage across the ignition tube to below the trigger voltage threshold when the controllable switch unit is on.

[0016] Optionally, the overvoltage protection device includes a transient voltage suppression diode, an electrostatic discharge diode, a voltage regulator diode, or a varistor.

[0017] Optionally, the fuse trigger circuit also includes a battery management module, which is also connected to the power supply sampling unit. The battery management module can control the fuse unit to blow or turn on based on the sampling data from the power supply sampling unit.

[0018] Optionally, the battery management module is also connected to the control terminal of the controllable switch unit, and the battery management module can also control the on / off state of the controllable switch unit according to the sampling data of the power supply sampling unit.

[0019] According to another aspect of the present invention, an on-board power supply system is provided, the battery power supply system comprising: a power supply and any of the fuse triggering circuits described in the preceding aspect.

[0020] According to another aspect of the present invention, an electric vehicle is provided, the electric vehicle including the on-board power supply system described in the preceding aspect.

[0021] The fuse triggering circuit, power supply system, and electric vehicle provided in this invention include a power supply sampling unit, a controllable switch unit, a control power supply, and an excitation fuse unit. The power supply sampling unit samples the power supply current in the power supply line and controls the controllable switch unit to open when the power supply current is less than a current threshold, and controls the controllable switch unit to close when the power supply current is greater than or equal to the current threshold. The excitation fuse unit is connected in series in the power supply line. One control terminal of the excitation fuse unit is connected to a first ground terminal, and the other control terminal is connected to the control power supply via the controllable switch unit. The excitation fuse unit can trigger fuse breaking when the controllable switch unit is closed, achieving short-circuit protective fusing of the power supply line. This scheme utilizes the on / off switching and transmission of electrical signals to trigger and control the excitation fuse unit. The circuit structure is simple and has a fast response time, improving the safety of the power supply line.

[0022] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a power supply line and its fuse triggering circuit provided in an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of another power supply line and its fuse triggering circuit provided in an embodiment of the present invention;

[0026] Figure 3 A schematic diagram illustrating the composition of another power supply line and its fuse triggering circuit provided in an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of another power supply line and its fuse triggering circuit is provided for embodiments of the present invention;

[0028] Figure 5 A schematic diagram of another power supply line and its fuse triggering circuit is provided for embodiments of the present invention;

[0029] Figure 6 A schematic diagram of another power supply line and its fuse triggering circuit is provided for embodiments of the present invention.

[0030] Figure 7 This is a schematic diagram of the composition of a battery power supply system provided in an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the composition of an electric vehicle provided in an embodiment of the present invention. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] To address the problems mentioned in the background art, this invention proposes a fuse trigger circuit that can be applied to the power supply line of an on-board power supply, wherein the on-board power supply can be an energy storage battery or an external charging gun. Figure 1 This is a schematic diagram illustrating the composition of a power supply line and its fuse triggering circuit according to an embodiment of the present invention. Figure 1 For simplicity, only a portion of the power supply line is shown, omitting the power source, appliances, and other power-related components. (Refer to...) Figure 1The fuse triggering circuit 100 includes an excitation fuse unit 101, a power supply sampling unit 102, a control power supply 103, and a controllable switch unit 104. The power supply sampling unit 102 is connected to the power supply line and can sample the power supply current I in the power supply line. The control terminal G of the controllable switch unit 104 is connected to the power supply sampling unit 102. The controllable switch unit 104 can remain in an open state when the power supply current I flowing through the power supply sampling unit 102 is less than a current threshold, and switch to a conducting state when the power supply current I is greater than or equal to the current threshold. The excitation fuse unit 101 is connected in series in the power supply line. One control terminal of the excitation fuse unit 101 is connected to the first ground terminal GND1, and the other control terminal is connected to the control power supply 103 via the controllable switch unit 104. The excitation fuse unit 101 can trigger fuse blowing when the controllable switch unit 104 is conducting.

[0035] Specifically, a power supply line refers to a line that uses a power supply to supply power to electrical appliances. For example, a power supply line can be a power supply line for an energy storage battery, a charging line for an on-board energy storage battery via an external charging gun, or a power supply line for on-board electrical appliances. The power supply sampling unit 102 is a component that samples and processes the power supply current I in the power supply line. The power supply sampling unit 102 is connected to the power supply line and can sample the collected power supply current I in the power supply line. Based on the relative relationship between the sampled data and the current threshold, it generates a corresponding on / off control signal for the controllable switch unit 104. For example, depending on the type of current sampling device in the power supply sampling unit 102, the power supply sampling unit 102 can have different connection methods with the power supply line. For example, if the current sampling device in the power supply sampling unit 102 is a current sampling resistor, the current sampling resistor is connected in series with the power supply line; while if the current sampling device in the power supply sampling unit 102 is a Hall current sensor, the coil of the Hall current sensor is wound around the power supply line. For simplicity, Figure 2 Only the connection method of the power supply sampling unit 102 connected in series with the power supply line is shown. In other embodiments, corresponding settings can be made according to the specific implementation method, and no restrictions are made here.

[0036] The current threshold refers to the short-circuit judgment threshold of the power supply line. It is generally set to the upper limit of the normal operating current range of the power supply line, and the specific value can be preset according to the power supply voltage and the specifications of the power supply line. Once the power supply current I exceeds the current threshold, it indicates that a short-circuit fault has occurred in the power supply line. For example, the power supply sampling unit 102 may include a current sampling resistor and a signal processing component. The current sampling resistor can be connected in series with the power supply line. The signal processing component can be connected to both ends of the current sampling resistor and can determine the power supply current I based on the voltage across the current sampling resistor. The current sampling resistor also generates a turn-off signal when the power supply current I is less than the current threshold to control the controllable switching unit 104 to remain off; once the power supply current I rises to be greater than or equal to the current threshold, the signal processing component generates a turn-on signal to control the controllable switching unit 104 to turn on.

[0037] The control power supply 103 provides power to the excitation fuse unit 101 and can provide a fusing voltage to the control terminal of the excitation fuse unit 101. The voltage provided by the control power supply 103 can be equal to the fusing voltage required for the excitation fuse unit 101 to control the power supply line to fuse. A controllable switch unit 104 is disposed between the control power supply 103 and one control terminal of the excitation fuse unit 101. Based on the control signal from the power supply sampling unit 102, it can connect or disconnect the line between the control power supply 103 and the other control terminal of the excitation fuse unit 101, thereby achieving state control of the excitation fuse unit 101. For example, the controllable switch unit 104 may include a field-effect transistor.

[0038] The excitation fuse unit 101 refers to an actively triggered fuse component that triggers a fuse state based on an external excitation signal. The excitation fuse unit 101 is connected in series in the power supply line. One control terminal of the excitation fuse unit 101 is connected to the first ground terminal GND1, and the other control terminal is connected to the control power supply 103 via the controllable switch unit 104. The excitation fuse unit 101 can control the power supply line to either fuse or remain connected depending on whether the two control terminals are connected to the control power supply. For example, the excitation fuse unit 101 may include a first access terminal a1, a second access terminal a2, a first control terminal b1, a second control terminal b2, a fuse element, and a control component. The fuse element can be connected in series in the power supply line via the first access terminal a1 and the second access terminal a2. The control component is connected to the first control terminal b1 and the second control terminal b2 respectively. The first control terminal b1 is connected to the first ground terminal GND1, where the first ground terminal GND1 is the vehicle body. The second control terminal b2 is connected to the control power supply 103 via the controllable switch unit 104. When the controllable switch unit 104 is turned off, no control power is connected between the first control terminal b1 and the second control terminal b2, and the control component is not triggered, thus maintaining the continuity of the circuit where the fuse is located; when the controllable switch unit 104 is turned on, the first control terminal b1 and the second control terminal b2 are connected to the control power, and the control component is triggered and controls the fuse to blow.

[0039] For example, when the supply current I is detected to be less than the current threshold, the power supply sampling unit 102 generates a corresponding shutdown control signal based on the sampled value of the supply current I to control the controllable switch unit 104 to shut down. When the controllable switch unit 104 remains off, the line between the control power supply 103 and the excitation fuse unit 101 is disconnected. The control power supply 103 cannot provide fusing voltage to the first control terminal b1 and the second control terminal b2 of the excitation fuse unit 101, and the power supply line remains on as long as the excitation fuse unit 101 is not triggered. However, when the supply current I is detected to be greater than or equal to the current threshold, the signal processing component generates a corresponding turn-on control signal based on the sampled value of the supply current I to control the controllable switch unit 104 to turn on. When the controllable switch unit 104 is on, the line between the control power supply 103 and the excitation fuse unit is connected. The control power supply 103 provides fusing voltage to the first control terminal b1 and the second control terminal b2 of the excitation fuse unit 101, which is then triggered, thereby fusing the power supply line.

[0040] The fuse triggering circuit provided in this embodiment includes a power supply sampling unit, a controllable switch unit, a control power supply, and an excitation fuse unit. The power supply sampling unit samples the power supply current in the power supply line and controls the controllable switch unit to open when the power supply current is less than a current threshold, and controls the controllable switch unit to close when the power supply current is greater than or equal to the current threshold. The excitation fuse unit is connected in series in the power supply line; one control terminal of the excitation fuse unit is connected to the first ground terminal, and the other control terminal is connected to the control power supply via the controllable switch unit. The excitation fuse unit can trigger fuse closure when the controllable switch unit is closed, achieving short-circuit protective fuse closure for the power supply line. This scheme utilizes the on / off state and transmission of electrical signals to trigger and control the excitation fuse unit. The circuit structure is simple and has a fast response time, improving the safety of the power supply line.

[0041] Optionally, Figure 2 This is a schematic diagram illustrating another power supply line and its fuse triggering circuit provided in an embodiment of the present invention. It should be noted that... Figure 2 The illustration only shows the case where the current sampling device is connected in series in the power supply line; other connection methods may be used in other embodiments. Figure 2 This is not intended to limit the scope of protection. Based on any of the foregoing embodiments, refer to… Figure 2 The power supply sampling unit 102 includes a current sampling device S and an isolation transformer T. The current sampling device S is connected in the power supply line; the primary winding of the isolation transformer T is connected in parallel with the current sampling device S, and the secondary winding of the isolation transformer T is connected between the control terminal G of the controllable switch unit 104 and the first ground terminal GND1. The isolation transformer T can isolate the primary and secondary sides and boost the voltage across the current sampling device S.

[0042] When the supply current I is less than the current threshold, the voltage controllable switch unit 104 across the secondary winding of the isolation transformer T remains off, the excitation fuse unit 101 is not triggered, and the power supply line remains on. When the supply current I is greater than or equal to the current threshold, the voltage controllable switch unit 104 across the secondary winding of the isolation transformer T is on, and the excitation fuse unit 101 controls the power supply line to fuse according to the connected control power supply.

[0043] Specifically, the current sampling device S refers to a sensor that samples the current of the connected circuit. It can be connected to the power supply line to sample the current of the power supply line. For example, the current sampling device S may include a current sampling resistor, a Hall current sensor, or a magnetoresistive current sensor. For example, on the one hand, continuing to refer to... Figure 2The current sampling device S can be a current sampling resistor. When the supply current I flows through it, the current sampling resistor can utilize its own resistance characteristics to generate a voltage drop across its terminals proportional to the supply current I, according to Ohm's law, thus sampling the current in the power supply line. The internal resistance of the current sampling resistor can be a fixed value between 5μΩ and 100μΩ. The small resistance design of the current sampling resistor can reduce energy waste and minimize the impact on the power supply line, thereby improving power quality. Furthermore, on the other hand, as... Figure 2 One of the parallel options, Figure 3 A schematic diagram of another power supply line and its fuse triggering circuit provided in an embodiment of the present invention is shown below. Figure 3 The current sampling device S can be a Hall current sensor, which includes a magnetic circuit φ and a Hall device H. The magnetic circuit φ of the Hall current sensor is wound around the power supply line, and the two ends of the Hall device H are respectively connected to the two ends of the primary winding of the isolation transformer T. The voltage across the Hall device H is positively correlated with the power supply current of the power supply line, thus realizing the sampling of the power supply current.

[0044] An isolation transformer T is a transformer installed between the power supply line and the excitation circuit (or control circuit) of the excitation fuse unit 101. It serves to isolate the power supply line and the fuse control circuit, and also provides voltage boosting. The isolation transformer T has a high-voltage design; its primary winding is connected to the current sampling device S at both ends, and the low-voltage end of the primary winding is also connected to the second grounding terminal GND2. One end of the secondary winding of the isolation transformer T is connected to the control terminal G of the controllable switch unit 104, and the other end is connected to the first grounding terminal GND1. The secondary winding of the isolation transformer T can use the boosted secondary voltage to control the switching on and off of the controllable switch unit 104. The turns ratio of the primary and secondary windings of the isolation transformer T can be associated with the current threshold, the internal resistance of the current sampling device S, and the conduction control voltage of the controllable switching unit 104, so that once the supply current I exceeds the current threshold, the secondary voltage of the isolation transformer T can control the controllable switching unit 104 to turn on. For example, the turns ratio of the isolation converter can be 1:N, where N can be an integer between 10 and 100.

[0045] For example, when the supply current I increases and exceeds the current threshold, the secondary voltage of the isolation transformer T also increases accordingly, exceeding the conduction voltage of the field-effect transistor in the controllable switching unit 104, thereby controlling the field-effect transistor to switch to the conduction state, causing the control power supply 103 to trigger the excitation fuse unit 101 to fuse the power supply line.

[0046] The power supply sampling unit in the fuse triggering circuit of the power supply line provided in this embodiment includes a current sampling device and an isolation transformer. The current sampling device is connected in the power supply line; the primary winding of the isolation transformer is connected in parallel with the current sampling device, and the secondary winding of the isolation transformer is connected between the control terminal of the controllable switching unit and the first ground terminal. The isolation transformer can boost the voltage across the current sampling device, thereby providing an appropriate control voltage for the controllable switching unit and realizing the on / off control of the controllable switching unit. The design of the isolation transformer can also isolate the circuits connected to the primary and secondary sides, preventing the influence of electrical signal fluctuations on the power supply line on the low-voltage fuse control circuit and improving the reliability of fuse control.

[0047] Optionally, Figure 4 This is a schematic diagram illustrating the composition of another power supply line and its fuse triggering circuit provided in an embodiment of the present invention. Based on any of the foregoing embodiments, refer to... Figure 4 The excitation fuse unit 101 includes a fuse element rx and an ignition tube MGG. The fuse element rx is connected in series in the power supply line. One end of the ignition tube MGG is connected to the first ground terminal GND1, and the other end is connected to the control power supply 103 via the controllable switch unit 104. When the controllable switch unit 104 remains on for more than a preset trigger time, the ignition tube MGG can trigger ignition and fuse element rx.

[0048] Specifically, the fuse element RX refers to a fuse connected in series in the power supply line, which melts based on the heat provided by the ignition tube MGG, thereby cutting off the power supply line. The ignition tube MGG is a control device that controls the fuse element RX to melt in response to the fusing voltage. When the controllable switch unit 104 is turned on, the two ends of the ignition tube MGG are respectively connected as the first control terminal b1 and the second control terminal b2 to the fusing voltage provided by the control power supply 103. The ignition tube MGG is triggered when the fusing voltage is applied and a preset trigger time is continuously applied. After triggering, an electric spark is generated in the ignition tube MGG and heat is generated, controlling the fuse element RX to melt.

[0049] It is important to note that at the instant the power supply is connected to the charging line, if there is an abnormality in the charging power supply or the charging line, a pulse current exceeding the current threshold may be generated in the power supply line. This pulse current flowing through the power supply sampling unit 102 will generate a corresponding voltage on the secondary side of the isolation transformer T, causing the controllable switching unit 104 to conduct abnormally, potentially leading to abnormal triggering of the ignition tube MGG. The inventors discovered that this pulse current has an extremely short duration, typically on the order of a few μs. Based on this, the inventors designed a preset trigger time of several hundred μs for the ignition tube MGG, far exceeding the duration of the pulse current. This prevents the pulse current generated by the power supply connecting to the charging line from affecting the short-circuit protection function, thus enabling the fuse trigger circuit 100 to have an anti-false triggering function and further improving the reliability of the fuse trigger circuit 100.

[0050] Optionally, Figure 5 This invention provides a schematic diagram of another power supply line and its fuse triggering circuit, based on any of the foregoing embodiments, referring to... Figure 5 The fuse trigger circuit 100 also includes an overvoltage protection device TVS. The overvoltage protection device TVS is located between the two control terminals b1 and b2 of the excitation fuse unit 101. When the controllable switch unit 104 is on, the overvoltage protection device TVS can limit the voltage between the two control terminals b1 and b2 of the excitation fuse unit 101 to below the trigger voltage threshold to ensure that the ignition tube MGG is triggered normally.

[0051] Specifically, the overvoltage protection device TVS refers to a transient voltage suppression device that can suppress the instantaneous voltage across its terminals to below a preset trigger voltage threshold. For example, the overvoltage protection device TVS may include a transient voltage suppression diode, an electrostatic discharge diode, a voltage regulator, or a varistor. The two ends of the overvoltage protection device TVS are respectively connected to the first control terminal b1 and the second control terminal b2 of the excitation fuse unit 101, thus limiting the voltage between the first control terminal b1 and the second control terminal b2 to below the trigger voltage threshold. The trigger voltage threshold refers to the upper limit of the trigger voltage range of the excitation fuse unit 101. It should be noted that, due to the inherent nature of the ignition tube MGG, if the current flowing through the ignition tube MGG exceeds the trigger current threshold, the ignition tube MGG may be damaged, causing it to fail to trigger. Therefore, based on the resistance of the ignition tube MGG and the trigger current threshold, the inventors determined the trigger voltage threshold. In this application, an overvoltage protection device TVS is connected between the first control terminal b1 and the second control terminal b2 to control the voltage value between the first control terminal b1 and the second control terminal b2 below the trigger voltage threshold, thereby preventing damage to the ignition tube MGG caused by the instantaneous pulse electrical signal generated by the unstable voltage of the control power supply 103, and further improving the reliability of the fuse trigger circuit 100.

[0052] Optionally, Figure 6 A schematic diagram of another power supply line and its fuse triggering circuit is provided for embodiments of the present invention. Figure 6 The connection relationship between the battery management module and the excitation fuse unit (or controllable switch unit) is omitted. Based on any of the aforementioned embodiments, refer to Figure 6 The fuse trigger circuit 100 also includes a battery management module (BMS), which is connected to the power supply sampling unit 102. The BMS can adjust the working state of the power supply and / or control the fuse unit 101 to blow or turn on based on the data sampled by the power supply sampling unit 102.

[0053] Specifically, the Battery Management System (BMS) is a system that monitors and manages the operating status of the power supply. Based on the sampling data from the power supply sampling unit 102, the BMS can control the operating status of the power supply. For example, the BMS can be connected to the power supply, and in the event of an overcurrent (I), the BMS can control the power supply to reduce its output power or stop supplying power. In addition to collecting current data from the power supply line, the BMS can also collect status information such as the power supply's output voltage and cell temperature, and control the power supply's operating status accordingly.

[0054] On one hand, the battery management module (BMS) can be connected to the control terminal G of the controllable switch unit 104. The BMS can also control the switching on and off of the controllable switch unit 104 based on the supply current I through the power supply sampling unit 102. On the other hand, the BMS can also be connected to the excitation fuse unit 101 via a corresponding drive circuit. It can control the state of the excitation fuse unit 101 based on the supply current I, thereby achieving redundant control of overcurrent fuse triggering, further improving the reliability and stability of the fuse triggering circuit 100, and enhancing the safety of the power supply line.

[0055] For example, the internal resistance of the current sampling resistor is 25μΩ, the gate turn-on voltage of the field-effect transistor is 5V, the control power supply provides a fuse voltage of 12V for the excitation fuse unit 101, and the amplification factor of the isolation transformer T is 70 times. Under normal operating conditions, when there is no short-circuit fault in the power supply line, the normal current flows through the current sampling resistor. The supply current I under normal operating conditions does not exceed 1000A. At this time, the maximum voltage difference across the current sampling resistor is also used as the primary voltage of the isolation transformer T.

[0056] V1 = 25μΩ * 1000A = 0.025V. The primary voltage is amplified 70 times by the isolation transformer T. After amplification, the secondary voltage V2 = 70 * 0.025V = 1.75V. At this time, the MOSFET is not turned on, and no current flows through the ignition transistor MGG. While the isolation transformer T is performing voltage boosting on the primary side, the voltage difference across the current sampling resistor can also be transmitted to the battery management module (BMS) for sampling and data storage of the supply current I.

[0057] In the event of a short circuit in the power supply line, the supply current I exceeds 3000A. At this point, the maximum voltage difference across the current sampling resistor is used as the primary voltage of the isolation transformer T: V1 = 25μΩ * 3000A = 0.075V. This primary voltage is amplified 70 times by the isolation transformer T, resulting in a secondary voltage V2 = 70 * 0.075 = 5.25V. At this point, the MOSFET turns on. The 12V power supply from the control power supply is supplied to the ignition diode MGG via the MOSFET, triggering MGG and blowing the fuse rx, thus disconnecting the power supply line. Since there is a risk that MGG may not trigger when the current exceeds 40A, the overvoltage protection device TVS limits the voltage rise across MGG to 40V during the control process after the MOSFET is turned on, preventing overvoltage faults in MGG.

[0058] Furthermore, this design also features protection against false triggering by pulse current. If the charging circuit corresponding to the power supply malfunctions, a pulse current will be generated in the power supply line during charging. When the pulse current is less than 2500A, the maximum voltage difference across the current sampling resistor, which is also the primary voltage of the isolation transformer T, is V1 = 25μΩ * 2500A = 0.0625V. After being amplified 70 times by the isolation transformer T, the secondary voltage becomes V2 = 70 * 0.0625 = 4.35V. At this time, the MOSFET is not turned on, and no current flows through the ignition tube MGG. When the pulse current exceeds 3000A, the primary voltage V1 exceeds 5V, and the MOSFET turns on. However, the duration of the pulse current is extremely short, on the order of a few μs, while the preset trigger time required for the ignition tube MGG is designed to be on the order of several hundred μs. Therefore, the ignition tube MGG will not be triggered by the pulse current. Only when the supply current I exceeds 3000A and the duration reaches several hundred μs can it be considered that a short circuit has occurred in the power supply line, at which point the ignition tube MGG will be triggered to cut off the power supply line.

[0059] This invention also provides an on-board power supply system. Figure 7 This is a schematic diagram of the composition of an on-board power supply system provided in an embodiment of the present invention. Based on the foregoing embodiments, refer to... Figure 7The vehicle power supply system 600 includes a power supply 105 and a fuse trigger circuit 100 for the vehicle power supply line in any of the aforementioned embodiments, which enables power supply to at least one electrical appliance 601. The power supply can be an energy storage battery or a charging gun.

[0060] This invention also provides an electric vehicle. Figure 8 This is a schematic diagram of the composition of an electric vehicle provided in an embodiment of the present invention. Based on the foregoing embodiments, refer to... Figure 8 The electric vehicle 700 includes the on-board power supply system 600 described in any of the foregoing embodiments. Exemplarily, the on-board power supply system 600 can be a power supply system for an energy storage battery, a power supply system for a DC-DC converter module, or a power supply system for charging the on-board energy storage battery from an external power source.

[0061] The present invention provides a fuse triggering circuit, a power supply system, and an electric vehicle. The circuit includes a power supply sampling unit, a controllable switch unit, a control power supply, and an excitation fuse unit. The power supply sampling unit samples the power supply current in the power supply line and controls the controllable switch unit to open when the power supply current is less than a current threshold, and controls the controllable switch unit to close when the power supply current is greater than or equal to the current threshold. The excitation fuse unit is connected in series in the high-voltage power supply line; the first control terminal of the excitation fuse unit is connected to the first ground terminal; the second control terminal of the excitation fuse unit is connected to the control power supply via the controllable switch unit. The excitation fuse unit can trigger fuse closure when the controllable switch unit is closed, achieving short-circuit protective fusing of the high-voltage power supply line. This scheme utilizes the on / off switching and transmission of electrical signals to trigger and control the excitation fuse unit, resulting in a simple circuit structure and fast response time, thus improving the safety of the power supply line.

[0062] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A fuse trigger circuit, characterized in that, include: Power supply sampling unit, controllable switching unit, control power supply and excitation fuse unit; The power supply sampling unit is connected to the power supply line, and the control terminal of the controllable switch unit is connected to the power supply sampling unit. The power supply sampling unit can sample the power supply current in the power supply line, and control the controllable switch unit to open when the power supply current is less than the current threshold, and control the controllable switch unit to open when the power supply current is greater than or equal to the current threshold. The excitation fuse unit is connected in series with the power supply line; One control terminal of the excitation fuse unit is connected to the first ground terminal, and the other control terminal is connected to the control power supply via the controllable switch unit; the excitation fuse unit can trigger fuse blowing when the controllable switch unit is turned on.

2. The fuse trigger circuit according to claim 1, characterized in that, The power supply sampling unit includes: a current sampling device and an isolation transformer; The current sampling device is connected to the power supply line; the primary winding of the isolation transformer is connected to both ends of the current sampling device, and the secondary winding of the isolation transformer is connected between the control terminal of the controllable switch unit and the first ground terminal. When the supply current is less than the current threshold, the voltage across the secondary winding of the isolation transformer controls the controllable switch unit to remain off, the excitation fuse unit is not triggered, and the power supply line remains on. When the supply current is greater than or equal to the current threshold, the voltage across the secondary winding of the isolation transformer controls the controllable switch unit to conduct, and the excitation fuse unit controls the power supply line to fuse according to the connected control power supply.

3. The fuse trigger circuit according to claim 2, characterized in that, The current sampling device includes a current sampling resistor, a Hall current sensor, or a magnetoresistive current sensor.

4. The fuse trigger circuit according to any one of claims 1-3, characterized in that, The excitation fuse unit also includes a fuse element and an ignition tube. The fuse element is connected in series in the power supply line. One end of the ignition tube is connected to the first ground terminal, and the other end is connected to the control power supply via the controllable switch unit. When the controllable switch unit remains on for more than a preset trigger time, the ignition tube can trigger ignition and fuse the fuse element.

5. The fuse trigger circuit according to claim 4, characterized in that, It also includes an overvoltage protection device, which is connected to both ends of the ignition tube. The overvoltage protection device can limit the voltage across the ignition tube to below the trigger voltage threshold when the controllable switching unit is on.

6. The fuse trigger circuit according to claim 5, characterized in that, The overvoltage protection device includes a transient voltage suppression diode, an electrostatic discharge diode, a voltage regulator diode, or a varistor.

7. The fuse trigger circuit according to any one of claims 1-6, characterized in that, It also includes a battery management module, which is connected to the power supply sampling unit. The battery management module can control the excitation fuse unit to blow or turn on based on the sampling data from the power supply sampling unit.

8. The fuse trigger circuit according to claim 7, characterized in that, The battery management module is also connected to the control terminal of the controllable switch unit, and the battery management module can also control the on / off state of the controllable switch unit according to the sampling data of the power supply sampling unit.

9. A vehicle-mounted power supply system, characterized in that, include: The power supply and the fuse triggering circuit according to any one of claims 1-8.

10. An electric vehicle, characterized in that, Includes the vehicle power supply system as described in claim 9.

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