Load control circuit and vehicle

Abstract

The utility model relates to the technical field of circuit protection, and provides a load control circuit and a vehicle. The load control circuit comprises a control unit, a switch tube, a shunting unit used for measuring current and a comparison unit connected with reference voltage. The output end of the control unit is connected with the grid electrode of the switch tube, the collector electrode of the switch tube is connected with a load so as to be connected with the positive electrode of a power supply through the load, the emitter electrode of the switch tube is connected with one end of the shunt unit, and the other end of the shunt unit is connected with the negative electrode of the power supply; the shunt unit is connected with the input end of the comparison unit, and the output end of the comparison unit is connected with the grid electrode of the switch tube. According to the load control circuit provided by the embodiment of the invention, the damage to the control circuit when the load is short-circuited can be reduced, and the safety of the control circuit is improved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit protection, and in particular to a load control circuit and a vehicle. Background Art

[0002] At present, some loads on new energy vehicles, such as heaters, can be integrated into the electric drive system of new energy vehicles, and the electric drive controller controls the loads to simplify the control circuit of new energy vehicles. However, if the load is short-circuited in this integration method, it will damage the vehicle's control circuit and affect the safety of the control circuit. Utility Model Content

[0003] The present application aims to solve at least one of the technical problems existing in the related art. To this end, the present application proposes a load control circuit and a vehicle, which can reduce the damage to the control circuit caused by a load short circuit and improve the safety of the control circuit.

[0004] According to the first aspect of the present application, the load control circuit includes: a control unit, a switch tube, a shunt unit for measuring current, and a comparison unit connected to a reference voltage;

[0005] The output end of the control unit is connected to the gate of the switch tube, the collector of the switch tube is connected to the load, so as to be connected to the positive electrode of the power supply through the load, the emitter of the switch tube is connected to one end of the shunt unit, and the other end of the shunt unit is connected to the negative electrode of the power supply;

[0006] The shunt unit is connected to the input end of the comparison unit, and the output end of the comparison unit is connected to the gate of the switch tube.

[0007] The load control circuit provided in the embodiment of the present application can, when a load short-circuit occurs, shut down the gate of the switch tube or the control unit by outputting a level signal from a comparison unit, thereby realizing shutdown after the load short-circuit, so that the components of the control circuit are protected, thereby reducing the damage to the control circuit caused by a load short-circuit and improving the safety of the control circuit.

[0008] According to one embodiment of the present application, the control unit includes a controller and an isolation driver;

[0009] The output end of the controller is connected to one end of the isolation driver, and the other end of the isolation driver is connected to the gate of the switch tube.

[0010] According to one embodiment of the present application, it further includes a first isolation unit;

[0011] An input end of the first isolation unit is connected to the gate of the switch tube, and an output end of the first isolation unit is connected to a first input end of the control unit.

[0012] According to an embodiment of the present application, the first isolation unit includes a digital isolator for isolating digital signal transmission.

[0013] According to one embodiment of the present application, the comparison unit includes a comparator and a signal amplifier;

[0014] The input end of the signal amplifier is connected to the shunt unit, the output end of the signal amplifier is connected to the input end of the comparator, and the output end of the comparator is connected to the gate of the switch tube.

[0015] According to an embodiment of the present application, the signal amplifier includes a differential signal amplifier for converting a differential signal into a single-ended signal.

[0016] According to one embodiment of the present application, it further includes a second isolation unit;

[0017] An input end of the second isolation unit is connected to an output end of the signal amplifier, and an output end of the second isolation unit is connected to a second input end of the control unit.

[0018] According to an embodiment of the present application, the second isolation unit includes an analog-to-digital converter.

[0019] According to an embodiment of the present application, the shunt unit includes a resistor whose resistance is less than or equal to a preset resistance.

[0020] A vehicle according to an embodiment of the second aspect of the present application includes a load control circuit as described in any of the above embodiments.

[0021] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0022] A load control circuit is provided, comprising a control unit, a switch tube, a shunt unit for measuring current, and a comparison unit connected to a reference voltage; the output end of the control unit is connected to the gate of the switch tube, the collector of the switch tube is connected to the load, so as to be connected to the positive electrode of the power supply through the load, the emitter of the switch tube is connected to one end of the shunt unit, and the other end of the shunt unit is connected to the negative electrode of the power supply; the shunt unit is connected to the input end of the comparison unit, and the output end of the comparison unit is connected to the gate of the switch tube, so that when a short circuit occurs in the load, the gate of the switch tube or the control unit can be turned off by outputting a level signal from the comparison unit, so as to realize the shutdown after the load is short-circuited, so that the components of the control circuit are protected, thereby reducing the damage to the control circuit caused by a load short circuit, and improving the safety of the control circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 is a first structural schematic diagram of a load control circuit provided by an embodiment of the present application;

[0025] Figure 2 is a second structural schematic diagram of a load control circuit provided in an embodiment of the present application;

[0026] Figure 3 is a third structural schematic diagram of a load control circuit provided in an embodiment of the present application;

[0027] Figure 4 is a fourth structural schematic diagram of a load control circuit provided in an embodiment of the present application;

[0028] Figure 5 This is a fifth structural diagram of a load control circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Below, the load control circuit provided in the embodiments of the present application will be introduced and explained in detail through several specific embodiments.

[0031] In one embodiment, a load control circuit is provided. Figure 1 As shown, a load control circuit provided in this embodiment includes: a control unit 101, a switch tube 102, a shunt unit 103 for measuring current, and a comparison unit 104 connected to a reference voltage;

[0032] The output end of the control unit 101 is connected to the gate of the switch tube 102, the collector of the switch tube 102 is connected to the load 10, so as to be connected to the positive electrode V+ of the power supply through the load 10, the emitter of the switch tube 102 is connected to one end of the shunt unit 103, and the other end of the shunt unit 103 is connected to the negative electrode V- of the power supply; the shunt unit 103 is connected to the input end of the comparison unit 104, and the output end of the comparison unit 104 is connected to the gate of the switch tube 102.

[0033] In some embodiments, the control unit 101 may include a controller for driving the switch tube, such as a controller that can output a control signal, such as an MCU (Microcontroller Unit) or an ECU (Electronic Control Unit).

[0034] The switch tube 102 may include a transistor, such as a triode or an insulated gate bipolar transistor. The load 10 connected to the switch tube 102 may be a load such as a PCT heater, one end of the load 10 may be connected to the collector of the switch tube 102, and the other end may be connected to the positive electrode V+ of the power supply.

[0035] The shunt unit 103 is used to collect the current passing through the load 10, and may include at least one resistor. To improve the current collection efficiency, the resistor of the shunt unit 103 may be a resistor with a resistance value less than or equal to a preset resistance value, wherein the preset resistance value may be set according to actual conditions, such as 1 mΩ.

[0036] The comparison unit 104 is connected to a reference voltage, and is used to compare the reference voltage with the voltage collected from the shunt unit 103, so as to output a corresponding level signal. Exemplarily, the comparison unit 104 may include a comparator, a first input terminal of the comparator is connected to the reference voltage Vref, a second input terminal of the comparator is connected to the shunt unit 103, and is used to collect the voltage across the shunt unit 103, and an output terminal of the comparator is connected to the gate of the switch tube 102, so as to compare the reference voltage with the voltage collected from the shunt unit 103, and output a corresponding level signal to control the switch tube 102.

[0037] When the load 10 does not need to be turned on, such as when the load 10 of the PTC heater does not need to be heated, the control unit 101 does not output a driving signal, and the switch tube 102 is disconnected, so that the power supply circuit of the load 10 is disconnected, and no current flows, so there is no voltage across the shunt unit 103. Since there is no voltage across the shunt unit 103, the comparison unit 104 can determine that the reference voltage is greater than the voltage across the shunt unit 103, and at this time the comparison unit 104 will not output a level signal, or output a low level.

[0038] When the load 10 needs to be turned on, the control unit 101 outputs a driving signal, and the switch tube 102 is turned on, so that the power supply circuit of the load 10 is closed, and the current of the load 10 passes through the shunt unit 103, generating a voltage drop at both ends. At this time, the voltage at both ends of the shunt unit 103 will be collected by the comparison unit 104 and compared with the reference voltage. If the load 10 is not short-circuited, the current flowing through the shunt unit 103 is small, so that the voltage at both ends of the shunt unit 103 is less than or equal to the reference voltage, and the comparison unit 104 will not output a level signal, or output a low level; if the load 10 is short-circuited, the current flowing through the shunt unit 103 is large, causing the voltage at both ends of the shunt unit 103 to exceed the reference voltage, causing the comparison unit 104 to switch state and output a high level voltage U to the switch tube 102. off , turn off the gate of the switch tube 102 or the control unit 101, so as to realize the shutdown after the load 10 is short-circuited, so that the control unit 101 and the switch tube 102 and other devices are protected. Since the voltage signal of the shunt unit 103 only passes through the comparison unit 104, when the load 10 is short-circuited, the response delay of the comparison unit 104 is small, and it can respond quickly, so as to quickly realize the shutdown of the switch tube 102 to protect the devices in the load control circuit. In the actual measurement, when the load 10 is short-circuited, if the comparison unit 104 uses a high-speed comparator, the delay time from the current exceeding the overcurrent point to the switch tube 102 being turned off is only about 2us. During the period from the short circuit of the load 10 to the shutdown of the switch tube 102, although the current will continue to rise, the energy generated is small because the time is short, which is not enough to damage the devices in the loop, so the devices in the control circuit can be effectively protected.

[0039] A load control circuit is provided, comprising a control unit, a switch tube, a shunt unit for measuring current, and a comparison unit connected to a reference voltage; the output end of the control unit is connected to the gate of the switch tube, the collector of the switch tube is connected to the load, so as to be connected to the positive electrode of the power supply through the load, the emitter of the switch tube is connected to one end of the shunt unit, and the other end of the shunt unit is connected to the negative electrode of the power supply; the shunt unit is connected to the input end of the comparison unit, and the output end of the comparison unit is connected to the gate of the switch tube, so that when a short circuit occurs in the load, the gate of the switch tube or the control unit can be turned off by outputting a level signal from the comparison unit, so as to realize the shutdown after the load is short-circuited, so that the components of the control circuit are protected, thereby reducing the damage to the control circuit caused by a load short circuit, and improving the safety of the control circuit.

[0040] To further reduce the risk of the control circuit, in some embodiments, such as Figure 2 As shown, the control unit 101 includes a controller 201 and an isolation driver 202;

[0041] The output end of the controller 201 is connected to one end of the isolation driver 202 , and the other end of the isolation driver 202 is connected to the gate of the switch tube 102 .

[0042] The isolation driver 202 may be an isolation driver chip, etc. It is used to achieve electrical isolation between the controller 201 and the switch tube 102, reducing the risk of loss of control of the control circuit. The controller 201 is used to output a drive signal, such as a level signal, and the isolation driver 202 electrically isolates the drive signal and then drives the switch tube 102 to turn on, so that the power supply circuit of the load 10 is closed.

[0043] To further improve the safety of the control circuit, such as Figure 3 As shown, in some embodiments, the load control circuit further includes a first isolation unit 105;

[0044] An input end of the first isolation unit 105 is connected to the gate of the switch tube 102 , and an output end of the first isolation unit 105 is connected to a first input end of the control unit 101 .

[0045] Exemplarily, the first isolation unit 105 can be an isolator for isolating digital signals, such as a digital isolator for isolating digital signal transmission, whose output end is connected to the controller 201. Since its output end is connected to the gate of the switching tube 102, its output end is also connected to the output end of the comparison unit 104 to ensure that the signal output from the output end to the controller 201 is exactly the same as the output signal received by its input end from the comparison unit 104.

[0046] When the load 10 is short-circuited, the comparison unit 104 will output a high level to turn off the switch tube 102. At the same time, the high level can be transmitted to the controller 201 via the first isolation unit 105, so that the controller 201 can trigger the state change of the drive signal when receiving the high level, such as stopping sending the drive signal, thereby maintaining the switch tube 102 off, so that the switch tube 102 can continue to remain in the off state after being turned off in response to the high level output by the comparison unit 104, thereby reducing the oscillation caused by the switch tube 102 being turned on again due to the decrease of the load 10 current and the comparison unit 104 recovering to a fault-free output state, thereby improving the safety of the control circuit.

[0047] In addition, after receiving the high level output by the comparison unit 104 , the controller 201 may also trigger a fault report indicating a load short circuit in response to the high level.

[0048] Considering that the voltage signal detected from the shunt unit 103 may be small, it is impossible to perform effective comparison. Therefore, in some embodiments, Figure 4 As shown, the comparison unit 104 includes a comparator 301 and a signal amplifier 302;

[0049] The input end of the signal amplifier 302 is connected to the shunt unit 103 , the output end of the signal amplifier 302 is connected to the input end of the comparator 301 , and the output end of the comparator 301 is connected to the gate of the switch tube 102 .

[0050] In some embodiments, the signal amplifier 302 is an amplifier for amplifying a voltage signal. Exemplarily, the signal amplifier 302 can be a differential to single-ended signal amplifier, such as a differential signal amplifier that converts a differential signal into a single-ended signal. The first input end of the signal amplifier 302 is connected to one end of the shunt unit 103, the second input end of the signal amplifier 302 is connected to the other end of the shunt unit 103, the output end of the signal amplifier 302 is connected to the first input end of the comparator 301, and the second input end of the comparator 301 is connected to the reference voltage.

[0051] The signal amplifier 302 is used to amplify the voltage signal at both ends of the shunt unit 103 and input it into the comparator 301, so that the comparator 301 compares the received amplified voltage signal with the reference voltage, and when the voltage signal exceeds the reference voltage, outputs a high level to turn off the switch tube 102. At the same time, the high level can be transmitted to the controller 201 via the first isolation unit 105, triggering the controller 201 to stop transmitting the drive signal used to turn on the switch tube 102, so that the switch tube 102 remains turned off.

[0052] In some embodiments, Figure 5 As shown, the load control circuit further includes a second isolation unit 106, the input end of the second isolation unit 106 is connected to the output end of the signal amplifier 302, and the output end of the second isolation unit 106 is connected to the second input end of the control unit 101. The second isolation unit 106 may include an isolator for implementing analog signal isolation, such as an ADC isolation chip or an analog-to-digital converter. The second input end of the control unit 101 may be a second input end of the controller 201.

[0053] Since the input end of the second isolation unit 106 is connected to the output end of the signal amplifier 302, and the output end of the second isolation unit 106 is connected to the second input end of the control unit 101, the voltage signal collected by the signal amplifier 302 can be sent to the control unit 101 through the second isolation unit 106, so that the control unit can collect the voltage signal and convert the corresponding current value to obtain the current working current of the load 10, thereby realizing the detection of the working current of the load 10.

[0054] In some embodiments, a vehicle is also provided, which is equipped with the load control circuit in any of the above embodiments.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A load control circuit, characterized in that: include: A control unit, a switch tube, a shunt unit for measuring current, and a comparison unit connected to a reference voltage; The output end of the control unit is connected to the gate of the switch tube, the collector of the switch tube is connected to the load, so as to be connected to the positive electrode of the power supply through the load, the emitter of the switch tube is connected to one end of the shunt unit, and the other end of the shunt unit is connected to the negative electrode of the power supply; The shunt unit is connected to the input end of the comparison unit, and the output end of the comparison unit is connected to the gate of the switch tube.

2. The load control circuit according to claim 1, characterized in that: The control unit includes a controller and an isolation driver; The output end of the controller is connected to one end of the isolation driver, and the other end of the isolation driver is connected to the gate of the switch tube.

3. The load control circuit according to claim 1, characterized in that: Also includes a first isolation unit; An input end of the first isolation unit is connected to the gate of the switch tube, and an output end of the first isolation unit is connected to a first input end of the control unit.

4. The load control circuit according to claim 3, characterized in that: The first isolation unit includes a digital isolator for isolating digital signal transmission.

5. The load control circuit according to any one of claims 1 to 4, characterized in that: The comparison unit includes a comparator and a signal amplifier; The input end of the signal amplifier is connected to the shunt unit, the output end of the signal amplifier is connected to the input end of the comparator, and the output end of the comparator is connected to the gate of the switch tube.

6. The load control circuit according to claim 5, characterized in that: The signal amplifier includes a differential signal amplifier for converting a differential signal into a single-ended signal.

7. The load control circuit according to claim 5, characterized in that: Also comprising a second isolation unit; An input end of the second isolation unit is connected to an output end of the signal amplifier, and an output end of the second isolation unit is connected to a second input end of the control unit.

8. The load control circuit according to claim 7, characterized in that: The second isolation unit includes an analog-to-digital converter.

9. The load control circuit according to claim 1, characterized in that: The shunt unit includes a resistor whose resistance is less than or equal to a preset resistance.

10. A vehicle, characterized in that: The load control circuit comprises the load control circuit as described in any one of claims 1 to 9.

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