CN216699605U

CN216699605U - Double-power supply system based on electric automobile

Info

Publication number: CN216699605U
Application number: CN202122932472.9U
Authority: CN
Inventors: 冯颖盈; 徐金柱; 汪青
Original assignee: Shenzhen Vmax Power Co Ltd
Current assignee: Shenzhen Vmax Power Co Ltd
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2022-06-07
Anticipated expiration: 2031-11-26

Abstract

The utility model discloses a double-power supply system based on an electric automobile, wherein the double-power supply system comprises a first charging loop and a second charging loop which are connected in parallel between a high-voltage direct-current input end and a low-voltage load in the automobile, and a communication and control module is connected between the first charging loop and the second charging loop; the communication and control module detects the states of the first charging circuit and the second charging circuit, and cuts off the first charging circuit and/or the second charging circuit to supply power to the low-voltage load in the vehicle according to the states; the utility model adopts two charging loops which operate independently without influencing each other, increases the redundancy of the charging system, grades the low-voltage load in the vehicle, and determines to supply power to the important first-level load or all the loads according to the electric quantity of the lithium battery, thereby further improving the system safety of the electric vehicle.

Description

Double-power supply system based on electric automobile

Technical Field

The utility model relates to a power circuit, in particular to a double power supply system based on an electric automobile.

Background

At present, the production scale of new energy automobiles is increased day by day, and the demand of low-voltage storage batteries is also increased day by day. The traditional lead storage battery has the characteristics of large volume, high weight, low energy density and high recovery cost, and the lithium battery has the characteristics of high energy density, long service life, low environmental pollution, high cost performance and the like, so that more and more lead storage batteries can be replaced by the lithium battery on future electric vehicles. Along with the increasing of vehicle-mounted mutual entertainment systems including vehicle-mounted sound systems, navigation systems, vehicle information systems, vehicle-mounted household electrical appliances and the like, the requirements of people on the output power of electric vehicles are higher and higher, namely, the power required by loads is increased, and along with the rise of vehicle-mounted intelligent auxiliary driving systems and the subsequent development of unmanned driving, the low-voltage power supply safety of the electric vehicles becomes the top of importance.

Referring to the existing power supply circuit shown in fig. 1, an electric vehicle converts high voltage into low voltage through a DCDC module, the low voltage firstly passes through a lithium battery and then reaches a load end, and the existing low-voltage lithium battery is considered for the comprehensive factors of cost and weight, so the capacity of the low-voltage lithium battery is in a reduction trend, which leads to the reduction of the battery capacity, while the existing vehicle-mounted low-voltage load is in an increase trend, and a contradiction which is not easy to generate is generated between the two trends.

Therefore, it is an urgent technical problem in the industry to develop a dual power supply system based on an electric vehicle to improve the power supply guarantee of electric vehicle equipment.

SUMMERY OF THE UTILITY MODEL

In order to solve the defects in the prior art, the utility model provides a double-power-supply system based on an electric automobile.

The technical scheme adopted by the utility model is to design a double-power supply system based on an electric automobile, which comprises a first charging loop and a second charging loop which are connected in parallel between a high-voltage direct current input end and an in-automobile low-voltage load, wherein a communication and control module is connected between the first charging loop and the second charging loop; the communication and control module detects the states of the first charging circuit and the second charging circuit and cuts off the first charging circuit and/or the second charging circuit to supply power to the low-voltage load in the vehicle according to the states.

The first charging loop comprises a first DC/DC module and a first battery E1 connected in series, and the second charging loop comprises a second DC/DC module and a second switching module connected in series.

The low-voltage load in the vehicle comprises a primary load and a secondary load, the primary load is connected with the first battery E1 and the second switch module, and the secondary load is connected with the second switch module.

The output end of the second switch module is connected with the secondary load and is connected with the primary load through the first switch module.

And a second battery E2 is connected between the positive output end and the negative output end of the second DC/DC module.

The output end of the first battery E1 is connected in series with a reverse flow prevention module, and the reverse flow prevention module comprises a diode D1.

The second switching module includes a first switching tube Q1.

The first switch module adopts an isolation Relay, or adopts a second switch tube Q2 and a third switch tube Q3 which are connected in series.

And a failure protection module is connected between the first DC/DC module and the first battery E1 in series.

The technical scheme provided by the utility model has the beneficial effects that:

(1) the two charging loops are used for ensuring the driving safety of the electric automobile, providing stable and reliable energy supply for basic functional safety loads of the electric automobile and providing safer technical support for the existing unmanned or auxiliary driving automobile; (2) the two charging loops operate independently without influencing each other, the redundancy of the charging system is increased, the system safety of the electric automobile is further improved, and a safer power supply system is provided for unmanned driving and intelligent driving; (3) the anti-reflux module is arranged to protect the lithium battery, and the switch circuit is arranged to physically isolate a fault circuit from a normal circuit, so that the safety of low-voltage power supply is protected; (4) the low-voltage load in the vehicle is classified, and the power supply to the important first-level load or all the loads is determined according to the electric quantity of the lithium battery, so that the system safety of the electric vehicle is further improved.

Drawings

The utility model is described in detail below with reference to examples and figures, in which:

FIG. 1 is a schematic block diagram of the prior art;

FIG. 2 is a basic functional block diagram of the first switching module not provided;

FIG. 3 is a schematic block diagram of a low voltage load in a vehicle divided into a first stage and a second stage;

FIG. 4 is a functional block diagram of a first switch module;

FIG. 5 is a functional block diagram of a fail safe module and an anti-reflux module;

fig. 6 is a circuit diagram of a first switching tube Q1 adopted by the second switching module and an isolation Relay adopted by the first switching module;

fig. 7 is a circuit diagram in which the first switching tube Q1 is provided on the negative pole of the output of the second charging circuit;

fig. 8 is a circuit diagram of a first switching tube Q1 adopted by a second switching module, a second switching tube Q2 and a third switching tube Q3 adopted by the first switching module in series;

fig. 9 is a waveform diagram of an output when both the first and second charging circuits are operating normally;

fig. 10 shows an abnormal condition of the dual power supply system.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

The utility model discloses a double-power-supply system based on an electric automobile, which is characterized in that a basic principle block diagram shown in figure 2 is referred, and the double-power-supply system comprises a first charging loop and a second charging loop which are connected in parallel between a high-voltage direct-current input end and a low-voltage load in the automobile, and a communication and control module is connected between the first charging loop and the second charging loop; the communication and control module detects the states of the first charging circuit and the second charging circuit and cuts off the first charging circuit and/or the second charging circuit to supply power to the low-voltage load in the vehicle according to the states. In practical use, the high-voltage direct current input end is connected with a high-voltage battery in the vehicle, the first charging circuit and the second charging circuit supply power when the first charging circuit and the second charging circuit are normal, the second charging circuit supplies power when the first charging circuit fails, and the first charging circuit supplies power when the second charging circuit fails. The first charging loop comprises a battery, and the battery supplies power for the functional safety load in the vehicle when the charging loop is in fault, so that the safety driving function of the electric vehicle is guaranteed, and the dangerous conditions such as power failure and the like during driving are avoided. The two charging loops operate independently without mutual influence, the redundancy of the charging system is increased, and the system safety of the electric automobile is improved.

In a preferred embodiment, the first charging loop comprises a first DC/DC module and a first battery E1 connected in series, and the second charging loop comprises a second DC/DC module and a second switching module connected in series. The communication and control module can control the operation and stop of the first DC/DC module and the second DC/DC module and can also control the on-off of the second switch module. When the second charging loop is normal, the second switch module is switched on, and the second charging loop supplies power to the low-voltage load in the vehicle; when the second charging loop is in fault, the second switch module is switched off, and the first charging loop supplies power to the low-voltage load in the vehicle. In the preferred embodiment, the first battery E1 is a lithium battery.

Referring to fig. 3, the low voltage load in the vehicle includes a primary load connected to the first battery E1 and the second switching module and a secondary load connected to the second switching module. The low-voltage load in the electric automobile is a low-voltage load and can be divided into a primary load (also called a low-voltage functional safety load) and a secondary load (also called other low-voltage loads) according to functions, the low-voltage functional safety load is a load for maintaining basic functions of the electric automobile, such as a steering wheel power assisting load, a display screen, a VCU (vehicle control unit) and the like, and other low-voltage loads are a vehicle-mounted sound system, a windshield wiper, a low-voltage motor and the like. Because the lithium battery has the advantages of high energy density and long service life, the lithium battery is arranged to supply power for the low-voltage functional safety load, and the basic safety function of the electric automobile is ensured. The second DC/DC module in the second charging loop supplies power to the low voltage functional safety load and other low voltage loads.

Referring to fig. 4, in order to isolate the first and second charging circuits from each other, the output terminal of the second switching module is connected to the secondary load and connected to the primary load through the first switching module.

Referring to fig. 7, in order to improve the power supply guarantee and realize dual power supply, in the preferred embodiment, a second battery E2 is connected between the positive and negative output terminals of the second DC/DC module. Therefore, even if the first charging loop and the second charging loop are damaged, all the functions of all the loads of the whole vehicle can still be normally used in a short time, and the vehicle self-checking reporting in an emergency state plays an important role. The second battery E2 may be a lithium battery or other kinds of batteries.

In the embodiment shown with reference to fig. 5, 6 and 8, a capacitor C2 is connected between the positive and negative output terminals of the second DC/DC module. Note that the capacitor C2 may be replaced by a battery.

Referring to fig. 5, a preferred embodiment is shown, wherein the output end of the first battery E1 is connected in series with a reverse flow prevention module, the reverse flow prevention module comprises a diode D1, and a failure protection module is connected in series between the first DC/DC module and the first battery E1. When the switch Q1 is turned on, the anti-reflux module can prevent the current in the second charging circuit from impacting the lithium battery, prolong the service life of the lithium battery and ensure the physical independent operation of the first charging circuit and the second charging circuit. The failure protection module can prevent the overshoot caused by the external voltage impacting the battery cell. The fail-safe means may be a diode, but it is not limited thereto, and in addition to a diode, the fail-safe means may be a Mos tube, or another device having the same or similar function, for example, another device having a reasonable one-way conductivity.

Referring to the embodiment shown in fig. 6, the second switching module includes a first switching tube Q1, and the first switching tube Q1 is controlled by the communication and control module. In fig. 5, 6 and 8, the first switch Q1 is disposed in the positive output line of the second switch module, but the first switch Q1 may also be disposed in the negative output line of the second switch module, as shown in fig. 7. The structure can realize the time sequence control and reduce the cost of an external control module of Q1. Specifically, the Q1 is arranged in the positive output line, the control end of the switch Q1 needs to be isolated and controlled, the Q1 is arranged in the negative output line, and the control end of the Q1 does not need to be isolated, so that the cost is indirectly saved, and the volume is reduced.

To establish physical isolation between the loads of the first and second charging circuits, in the embodiment shown in fig. 6, the first switching module employs an isolation Relay. In the embodiment shown in fig. 8, the first switching module employs a second switching tube Q2 and a third switching tube Q3 connected in series. The first charging loop and the second charging loop are provided with physical isolation between loads, so that the whole low-voltage power supply system can be prevented from being damaged after the primary load circuit and the secondary load circuit are damaged.

Here, for example, the power of the first charging loop is 1KW, which satisfies the charging and primary load (functional safety load) of the lithium battery, and the power provided by the second charging loop is 3KW, which satisfies all low-voltage loads in the vehicle, including the functional safety load, when the second charging loop fails, the first charging loop satisfies the functional safety load of the entire vehicle and cuts off other low-voltage loads, so as to ensure the normal driving safety of the vehicle, and when the first charging loop fails, the second charging loop satisfies all low-voltage loads, so that the vehicle can be used normally.

Fig. 9 is a waveform diagram of an output when both the first and second charging circuits are operating normally. One horizontal line at the top of the figure is the output voltage waveform of the second charging circuit (DC/DC module 2). The middle horizontal line in the figure is the output voltage waveform of the first charging circuit (DC/DC module 1), which is operating, at output voltage, but not loaded. One horizontal line below the graph is a graph of the voltage waveform (output waveform) measured on the load.

Fig. 10 shows an abnormal condition of the dual power supply system. (a) When the DC/DC module 1 stops outputting, the output oscillogram of each module; (b) when the DC/DC module 1 is abnormally unloaded, the output oscillogram of each module; (c) when the DC/DC module 2 stops outputting, the output oscillogram of each module; (d) and when the DC/DC module 2 is abnormally unloaded, the output waveform diagram of each module. According to the four diagrams, the actual output is stable voltage when any one of the DC/DC module 1 and the DC/DC module 2 has a problem, so that the lithium battery and the load can work normally, namely the two charging loops operate independently without influencing each other, the redundancy of the charging system is increased, and the system safety of the electric automobile is further improved.

The foregoing examples are illustrative only and are not intended to be limiting. Any equivalent modifications or variations without departing from the spirit and scope of the present application should be included in the claims of the present application.

Claims

1. A double-power-supply system based on an electric automobile is characterized by comprising a first charging loop and a second charging loop which are connected in parallel between a high-voltage direct-current input end and a low-voltage load in the automobile, wherein a communication and control module is connected between the first charging loop and the second charging loop; the communication and control module detects the states of the first charging circuit and the second charging circuit and cuts off the first charging circuit and/or the second charging circuit to supply power to the low-voltage load in the vehicle according to the states.

2. The electric vehicle-based dual power supply system of claim 1, wherein the first charging loop comprises a first DC/DC module and a first battery E1 connected in series, and the second charging loop comprises a second DC/DC module and a second switching module connected in series.

3. The electric-vehicle-based dual power supply system according to claim 2, wherein the in-vehicle low-voltage load comprises a primary load and a secondary load, the primary load is connected with the first battery E1 and the second switch module, and the secondary load is connected with the second switch module.

4. The electric vehicle-based dual power supply system as claimed in claim 3, wherein the output terminal of the second switch module is connected to the secondary load and is connected to the primary load through the first switch module.

5. The electric-vehicle-based dual power supply system according to claim 4, wherein a second battery E2 is connected between the positive and negative output terminals of the second DC/DC module.

6. The dual electric supply system based on electric vehicle of claim 5, wherein the output terminal of the first battery E1 is connected in series with a reverse flow prevention module, and the reverse flow prevention module comprises a diode D1.

7. The electric vehicle-based dual power supply system of claim 6, wherein the second switching module comprises a first switching tube Q1.

8. The electric vehicle-based dual power supply system as claimed in claim 7, wherein the first switching module employs an isolation Relay, or a second switching tube Q2 and a third switching tube Q3 connected in series.

9. The electric vehicle-based dual power supply system of claim 2, wherein a fail-safe module is connected in series between the first DC/DC module and the first battery E1.