Vehicle-mounted power supply protection circuit

Abstract

The utility model provides a vehicle-mounted power supply protection circuit, which is applied to absorbing voltage spikes on a direct current bus when vehicle equipment works, and comprises an overvoltage absorption module, a super capacitor bank and an acquisition control board, the overvoltage absorption module is in communication connection with the super capacitor bank, and the super capacitor bank is in communication connection with the acquisition control board; the overvoltage absorption module, the super capacitor bank and the acquisition control panel are arranged between the positive electrode and the negative electrode of the input end of the vehicle-mounted power supply, and the positive electrode of the output end of the vehicle-mounted power supply is provided with a CAN communication interface; and the acquisition control board is fused and matched with the overvoltage absorption module and the super capacitor bank. According to the magnitude of energy at the front end of a vehicle-mounted power supply, voltage spikes generated by an inductive load in the running process of a vehicle are automatically matched and absorbed, meanwhile, the absorbed energy can be stably fed back to a direct-current bus, and normal work of other equipment on the inductive load direct-current bus is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle-mounted power supply protection circuits, in particular to a vehicle-mounted power supply protection circuit. Background Art

[0002] With the increasing demand for information and digital equipment, many vehicles are equipped with information electronic equipment. The main characteristics of such equipment are: resistance, capacitance, inductance, etc. When the equipment is turned on or off, there will be a large current shock, causing the DC power supply bus voltage to rise or fall seriously. The unstable bus voltage will cause some equipment to work abnormally or even be damaged. Therefore, it is necessary to design a voltage surge shock absorption protection control circuit.

[0003] The current surge absorption circuit is mainly aimed at AC input products, and the protection mechanism is not flexible. It mainly cuts off the input source, and there are very few products with absorption. There are very few products with DC high-power absorption. Currently, DC absorption protection mainly relies on TVS to absorb spikes, but due to the power limitation of TVS tubes, the TVS is damaged when the power is too large, and the absorption effect is poor. It cannot meet the working needs of complex electronic equipment and will cause equipment damage. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a vehicle-mounted power supply protection circuit, which is used to absorb voltage spikes on the DC bus when vehicle equipment is working, including an overvoltage absorption module, a supercapacitor group and an acquisition control board, wherein the overvoltage absorption module is communicatively connected to the supercapacitor group, and the supercapacitor group is communicatively connected to the acquisition control board; the overvoltage absorption module, the supercapacitor group and the acquisition control board are arranged between the positive and negative poles of the vehicle-mounted power supply input end, and the positive pole of the vehicle-mounted power supply output end is provided with a CAN communication interface; the acquisition control board integrates and matches the overvoltage absorption module and the supercapacitor group.

[0005] Furthermore, the overvoltage absorption module includes a plurality of capacitors connected in parallel, a fuse F1, and a TVS tube connected in series with the fuse F1. The number and type of the TVS tubes match the power level during the voltage spike absorption.

[0006] Furthermore, when the voltage peak at the power input terminal exceeds the voltage value of the TVS tube, the TVS tube is turned on.

[0007] Furthermore, the capacitor group includes multiple single super capacitors, and each of the multiple single super capacitors is equipped with a voltage-equalizing discharge circuit. The surge energy absorbed by the overvoltage absorption module is stored by the voltage-equalizing discharge circuit and then fed back to the DC bus for use by external devices.

[0008] Furthermore, there are 10 single supercapacitors.

[0009] Furthermore, the circuit also includes a temperature sensor, and the temperature sensor collects temperature changes when the supercapacitor group is working.

[0010] Furthermore, the acquisition control board includes an auxiliary power supply circuit, a CPU controller circuit, a CAN communication circuit, a peak voltage and time sampling circuit and a relay control circuit, wherein the output end of the auxiliary power supply circuit is connected to the input end of the CPU controller circuit; the output end of the CPU controller circuit is connected to the input end of the supercapacitor group; the CAN communication circuit is connected to the CAN communication interface; the peak voltage and time sampling circuit detects the amplitude and duration of the external voltage spike; the relay control circuit is arranged between the positive and negative poles of the vehicle-mounted power supply output end to control the on-off of the supercapacitor group and the overvoltage absorption module.

[0011] Furthermore, the circuit also includes a temperature sensor, and the temperature sensor collects temperature information of the supercapacitor group when it is working.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] The utility model provides an overvoltage absorption module and a supercapacitor group, which can automatically match and absorb the voltage spikes generated by the inductive load during vehicle operation according to the energy size of the front end of the vehicle power supply, and can also smoothly feed back the absorbed energy to the DC bus, thereby ensuring the normal operation of other equipment on the inductive load DC bus. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the principle diagram of the utility model;

[0015] Figure 2 is a circuit diagram of the overvoltage absorption module in the utility model;

[0016] Figure 3-1 It is a sub-circuit diagram of the supercapacitor group in the utility model;

[0017] Figure 3-2 It is a sub-circuit diagram of the supercapacitor group in the utility model;

[0018] Figure 3-3 It is a sub-circuit diagram of the supercapacitor group in the utility model;

[0019] Figure 4 This is the auxiliary power supply circuit diagram of the utility model;

[0020] Figure 5It is the CAN communication circuit diagram in the utility model;

[0021] Figure 6 It is the peak voltage and time sampling circuit diagram of the utility model;

[0022] Figure 7 This is a relay control circuit diagram in the utility model.

[0023] In the figure: 1. Overvoltage absorption module; 2. Supercapacitor group; 3. Data acquisition control board; 4. CAN communication interface. DETAILED DESCRIPTION

[0024] In order to make the technical scheme and technical effect of the utility model clearer, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments.

[0025] like Figure 1 As shown, the utility model aims to provide an on-board power protection circuit that can absorb voltage spikes on the DC bus when the vehicle equipment is working. The on-board power protection circuit mainly has two-level energy absorption measures: an overvoltage absorption module 1 (primary absorption module) and a super capacitor group 2 (secondary absorption module), and the primary and secondary absorption modules are better integrated and matched by controlling the acquisition board. The primary absorption module, the secondary absorption module and the acquisition control board 3 are arranged between the positive and negative poles of the power input terminal. It also includes a CAN communication interface 4 and a temperature sensor, wherein the CAN communication interface 4 is connected to the positive pole of the power output terminal; the temperature sensor collects temperature information of the super capacitor group 2 when it is working.

[0026] The overvoltage absorption module 1 mainly includes a plurality of high-power TVS tubes connected in series, and the number and type of the high-power TVS tubes match the power level during voltage spike absorption.

[0027] The supercapacitor group 2 is mainly used to absorb and store surge energy generated by equipment on the vehicle.

[0028] The control acquisition board is used to detect the peak value of the DC bus input surge voltage. According to the size of the peak value, it controls whether the supercapacitor group 2 needs to be connected for energy absorption and disconnected. It can also detect the charging state, discharging state, working temperature, etc. of the supercapacitor group 2.

[0029] like Figure 2 As shown, the overvoltage absorption module 1 includes multiple capacitors connected in parallel, a fuse F1, and a high-power TVS tube connected in series with the fuse F1. The DC power is input into the positive electrode of the primary absorption module and filtered by capacitors C101, C102, C103, C104, and C105, and then enters the TVS tube after the fuse F1.

[0030] The TVS is composed of three (V103~V105) SM8S12A connected in series. The absorption voltage of a single TVS tube SM8S12A is 13.3V, and the maximum power absorption is 6600W. The absorption voltage of three TVS tubes is 39.9V, and the maximum power absorption is 18.8kW.

[0031] When 28V is input, there is no surge voltage spike at the input end of the first-level absorption module. At this time, the 28V positive potential passes through the fuse F1 to the resistor R103-1 and the resistor R104-2. The resistor R103-2 is connected to the light-emitting diode V1, and the resistor R104-1 is connected to the base of the transistor Q103. At this time, the base of the transistor Q103 is at a high level, and the green light of the light-emitting diode V101 is always on.

[0032] When the input exceeds 39.9V, there is a surge voltage spike at the input end of the first-level absorption module. At this time, the TVS tube switch is turned on, the resistor R101-1 is at a low level, the base of the transistor Q101 is turned on at a low level, and the red light of the light-emitting diode V102 is on. At this time, the first-level absorption module enters the surge voltage spike absorption state.

[0033] like Figure 3-1 , 3-2 As shown in 3-3, the supercapacitor group 2 includes 10 single supercapacitors, and all 10 single supercapacitors are equipped with a voltage-equalizing discharge circuit. The surge energy absorbed by the overvoltage absorption module 1 is discharged or stored through the voltage-equalizing discharge circuit and then fed back to the DC bus for use by external devices. (It should be noted that: Figure 3-1 , Figure 3-2 as well as Figure 3-3 The original circuit diagram is a complete circuit diagram, i.e. the circuit of supercapacitor group 2. For the sake of clear display, it is divided into three sub-circuit diagrams. )

[0034] like Figure 4-7 As shown, the acquisition control board 3 mainly includes an auxiliary power supply circuit, a CPU controller circuit, a CAN communication circuit, a peak voltage and time sampling circuit, and a relay control circuit.

[0035] Auxiliary power supply circuit: The output end of the auxiliary power supply circuit is connected to the input end of the CPU controller circuit, which mainly converts 18V~36V DC into 5V and 3.3V low-voltage DC to provide reliable power supply for the subsequent operational amplifier and CPU.

[0036] CPU controller circuit: The CPU controller mainly collects the amplitude and duration of the external peak voltage, temperature, and controls the connection and disconnection of the supercapacitor group 2.

[0037] CAN communication circuit: The CAN communication circuit is connected to the CAN communication interface 4 and reports the sampled relevant information to the outside through the CAN communication interface 4.

[0038] Peak voltage and time sampling circuit: detects the amplitude and duration of the external voltage spike voltage, and provides a basis for the connection of supercapacitor group 2.

[0039] Relay control circuit: The relay control circuit is arranged between the positive pole of the power output end and the input positive pole of the primary absorption module to control the on and off of the super capacitor group 2 and the overvoltage absorption module 1.

[0040] The control board 3 detects and determines the surge input peak. If the peak value is too high and lasts for a long time, the supercapacitor group 2 is connected in parallel to both ends of the overvoltage absorption module 1 by controlling the relay K6 to enter the two-stage absorption. At the same time, the energy can be stored in the supercapacitor group 2.

[0041] In the information age, vehicles have more and more inductive loads. During vehicle operation, sudden loading or unloading may cause large surge voltage spikes. The protection circuit provided by the utility model can automatically match and absorb the voltage spikes generated by the inductive load according to the size of the front-end energy, ensuring the normal operation of other equipment on the inductive load bus. It can also absorb the energy in the inductive load circuit, and at the same time, the absorbed energy can be smoothly fed back to the DC bus.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vehicle power protection circuit, used to absorb voltage spikes on the DC bus when vehicle equipment is working, characterized in that: The invention comprises an overvoltage absorption module (1), a supercapacitor group (2) and a collection control board (3), wherein the overvoltage absorption module (1) is communicatively connected to the supercapacitor group (2), and the supercapacitor group (2) is communicatively connected to the collection control board (3); the overvoltage absorption module (1), the supercapacitor group (2) and the collection control board (3) are arranged between the positive pole and the negative pole of the vehicle power input terminal, and the positive pole of the vehicle power output terminal is provided with a CAN communication interface (4); the collection control board (3) integrates and matches the overvoltage absorption module (1) and the supercapacitor group (2).

2. The vehicle-mounted power supply protection circuit according to claim 1, characterized in that: The overvoltage absorption module (1) comprises a plurality of capacitors connected in parallel, a fuse F1 and a TVS tube connected in series with the fuse F1, wherein the number and type of the TVS tubes match the power level during voltage spike absorption.

3. The vehicle-mounted power supply protection circuit according to claim 2, characterized in that: When the voltage peak at the vehicle power input terminal exceeds the voltage value of the TVS tube, the TVS tube is turned on.

4. The vehicle-mounted power supply protection circuit according to claim 1, characterized in that: The supercapacitor group (2) comprises a plurality of single supercapacitors, each of which is provided with a voltage-equalizing discharge circuit. The surge energy absorbed by the overvoltage absorption module (1) is stored by the voltage-equalizing discharge circuit and then fed back to the DC bus for use by external devices.

5. The vehicle-mounted power supply protection circuit according to claim 4, characterized in that: There are 10 single super capacitors.

6. The vehicle-mounted power supply protection circuit according to claim 1, characterized in that: The acquisition control board (3) comprises an auxiliary power supply circuit, a CPU controller circuit, a CAN communication circuit, a peak voltage and time sampling circuit and a relay control circuit, wherein the output end of the auxiliary power supply circuit is connected to the input end of the CPU controller circuit; the output end of the CPU controller circuit is connected to the input end of the super capacitor group (2); the CAN communication circuit is connected to the CAN communication interface (4); the peak voltage and time sampling circuit detects the amplitude and duration of the external voltage peak; and the relay control circuit is arranged between the positive and negative electrodes of the vehicle power output end to control the on-off of the super capacitor group (2) and the overvoltage absorption module (1).

7. The vehicle-mounted power supply protection circuit according to claim 1, characterized in that: The circuit also includes a temperature sensor, which collects temperature information of the supercapacitor group (2) when it is working.

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