CN104709104B - Method and system for rapidly switching battery packs of electric vehicle - Google Patents

Abstract

The invention provides a quick-change method and a quick-change system for an electric vehicle battery pack, wherein the quick-change method for an electric vehicle battery pack includes: configuring a first battery pack and a second battery pack on the electric vehicle that can independently serve as power sources A battery pack; the output end of the first battery pack is connected in parallel with the output end of the second battery pack; when the SOC of the first battery pack currently powered is less than a predetermined threshold, switch to the second battery pack for power supply. The quick-change method and quick-change system for the electric vehicle battery pack of the present invention effectively solve the problem of short mileage of the electric vehicle in the prior art.

Description

Quick-change method and quick-change system for electric vehicle battery pack

technical field

The invention relates to the field of electric vehicle equipment, in particular to a quick-change method and a quick-change system for electric vehicle battery packs.

Background technique

In the prior art, electric vehicles mainly install a power battery on the chassis. When the chassis power battery SOC (abbreviation of Stateof Charge, refers to the ratio of charging capacity to rated capacity, expressed as a percentage) is too low to work, it cannot work normally. The mileage of electric vehicles is short.

Moreover, it is necessary to charge the power battery of the electric vehicle for a long time, which wastes a lot of time.

Contents of the invention

The object of the present invention is to provide a quick-change method and a quick-change system for electric vehicle battery packs that solve the problem of the short mileage of the electric vehicle.

In order to achieve the above object, according to one aspect of the present invention, a method for quickly changing battery packs of electric vehicles is provided, including: configuring a first battery pack and a second battery pack on the electric vehicle that can be independently used as power sources; The output end of the first battery pack is connected in parallel with the output end of the second battery pack; when the SOC of the first battery pack currently powered is less than a predetermined threshold, switch to the second battery pack for power supply.

Further, both the first battery pack and the second battery pack include a plurality of modules that can be disassembled individually, and each of the modules can be charged independently in a household electricity environment.

Further, a first main positive relay is arranged on the internal wiring of the output terminal of the first battery pack, and the first main positive relay is connected in parallel with the first diode; the internal wiring of the output terminal of the second battery pack is There is a second main positive relay connected in parallel with a second diode; when the first battery pack supplies power, the first main positive relay is closed, and the second main positive relay disconnect.

Further, when the electric vehicle is in a driving state, the step of switching to the second battery pack for power supply includes: the first main positive relay is disconnected, and the first battery pack passes through the The first diode supplies power to the outside; the second main positive relay is closed, and the second battery pack supplies power to the outside through the second main positive relay; the voltage of the second battery pack is greater than that of the first battery pack Under the condition of the voltage, the unidirectional conduction of the first diode is turned off.

Further, after the step of turning off the first diode that conducts unidirectionally, the method further includes: making the low-voltage system of the first battery pack enter a sleep mode through a gateway controller.

Further, when the electric vehicle is in a parked state, the step of switching to the second battery pack for power supply includes: enabling the low-voltage system of the first battery pack to enter a sleep mode through a gateway controller, During the restart process of the electric vehicle, the low-voltage system of the second battery pack is activated and the low-voltage system of the first battery pack is prohibited from being activated, so that the power is only supplied by the second battery pack.

According to another aspect of the present invention, a quick-change system for battery packs of electric vehicles is provided, including: a first battery pack and a second battery pack that can be independently used as power sources, and are arranged on the electric vehicle. The output end of the battery pack is connected in parallel with the output end of the second battery pack; the switching unit is configured to: switch to the second battery pack for power supply when the SOC of the first battery pack currently powering power is less than a predetermined threshold.

Further, both the first battery pack and the second battery pack include a plurality of modules that can be disassembled independently, and each of the modules can be charged independently in a household electricity environment.

Further, a first main positive relay is arranged on the internal wiring of the output terminal of the first battery pack, and the first main positive relay is connected in parallel with the first diode; the internal wiring of the output terminal of the second battery pack is There is a second main positive relay connected in parallel with a second diode; when the first battery pack supplies power, the first main positive relay is closed, and the second main positive relay disconnect.

Further, when the electric vehicle is in a driving state, the switching unit is specifically configured to: disconnect the first main positive relay, and the first battery pack supplies power to the outside through the first diode ; The second main positive relay is closed, and the second battery pack is powered externally through the second main positive relay; under the condition that the voltage of the second battery pack is greater than the voltage of the first battery pack, The first diode that conducts in one direction is turned off; when the electric vehicle is in a parked state, the switching unit is specifically configured to: enable the low-voltage system of the first battery pack to enter sleep through a gateway controller In the mode, the low-voltage system of the second battery pack is activated during the restart process of the electric vehicle and the low-voltage system of the first battery pack is prohibited from being activated, so that the power supply is only supplied by the second battery pack.

The electric vehicle is equipped with two power sources, and the two power sources are connected in parallel. When the power of one power source (the first battery pack is generally the priority power source) is too low, switch to another power source (the second battery pack is generally the priority power source). Standby power supply) work, which can effectively increase the mileage of electric vehicles.

Those skilled in the art will be more aware of the above and other objects, advantages and features of the present invention according to the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of illustration and not limitation with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the attached picture:

Fig. 1 is a schematic diagram of a quick change method for an electric vehicle battery pack according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of step S30 of the quick change method for the electric vehicle battery pack shown in Fig. 1;

3 is a schematic diagram of a quick-change system for an electric vehicle battery pack according to an embodiment of the present invention;

Fig. 4 is the topological diagram of the first battery pack of the quick-change system of the electric vehicle battery pack shown in Fig. 3;

Fig. 5 is the topological diagram of the second battery pack of the quick-change system of the electric vehicle battery pack shown in Fig. 3;

FIG. 6 is a schematic structural view of the first battery pack of the quick-change system for the battery pack of the electric vehicle shown in FIG. 3 .

detailed description

Fig. 1 is a schematic diagram of a quick replacement method for an electric vehicle battery pack according to an embodiment of the present invention. The quick change method of the electric vehicle battery pack of the present embodiment comprises the following steps:

S10: The electric vehicle is equipped with a first battery pack and a second battery pack which can be independently used as power sources; the output end of the first battery pack is connected in parallel with the output end of the second battery pack.

S20: Determine whether the SOC of the first battery pack currently supplying power is smaller than a predetermined threshold.

S30: Switch to the second battery pack for power supply when the SOC of the first battery pack that is currently supplying power is less than a predetermined threshold. If the SOC of the first battery pack currently supplying power is greater than the predetermined threshold, continue to execute step S30.

Among them, SOC is the abbreviation of State of Charge, which refers to the ratio of charging capacity to rated capacity, expressed in percentage. The battery has a rated capacity, and it can be charged at a certain rate for a certain period of time to obtain the charging capacity, and the ratio of the charging capacity to the rated capacity is the SOC. The predetermined threshold can be set according to the minimum output power of the battery pack or according to avoiding damage to the battery when the power of the battery pack is exhausted. Generally, the predetermined threshold is set between 5% and 8%.

The electric vehicle is equipped with two power sources, and the two power sources are connected in parallel. When the power of one power source (the first battery pack is generally the priority power source) is too low, switch to another power source (the second battery pack is generally the priority power source). Standby power supply) work, which can effectively increase the mileage of electric vehicles.

Considering the quick replacement and charging of the battery pack, the quick change method of this embodiment also includes: both the first battery pack and the second battery pack include a plurality of modules that can be disassembled separately, and each module can be used in a household electricity environment. charge separately.

Both the first battery pack and the second battery pack are composed of n (n ≥ 1, and an integer) modules, and the modules are connected to the battery box through quick connectors to facilitate quick replacement of the modules. The weight of each module Ensure adults move and replace normally. Each module can be charged independently at home, which is convenient, fast and safe.

The quick change method of this embodiment further includes: a first main positive relay is arranged on the internal wiring of the output end of the first battery pack, and the first main positive relay is connected in parallel with the first diode. A second main positive relay is arranged on the internal wiring of the output end of the second battery pack, and the second main positive relay is connected in parallel with a second diode. When the first battery pack supplies power, the first main positive relay is closed, and the second main positive relay is open. Both the first diode and the second diode are low-voltage-drop high-overcurrent type diodes, and are mainly used for reverse anti-reverse and forward conduction.

In this embodiment, further preferably, the step of switching the power supply of the battery pack is optimized. Referring to FIG. 2 , during the step of switching the power supply of the battery pack, it is first necessary to detect whether the electric vehicle is in a driving state or a parking state. Wherein, under the condition that the electric vehicle is in a driving state, the step of switching to the second battery pack for power supply includes:

S41: the first main positive relay is disconnected, and the first battery pack supplies power to the outside through the first diode;

S42: The second main positive relay is closed, and the second battery pack supplies power to the outside through the second main positive relay; when the voltage of the second battery pack is greater than the voltage of the first battery pack, the unidirectionally conducting first diode is turned off. open.

S43: Enabling the low-voltage system of the first battery pack to enter a sleep mode through the gateway controller.

And when the electric vehicle is in the parking state, the steps of switching to the second battery pack for power supply include:

S51: Make the low-voltage system of the first battery pack enter sleep mode through the gateway controller, start the low-voltage system of the second battery pack and prohibit the low-voltage system of the first battery pack from being started during the restart process of the electric vehicle, so that only the second battery Package power supply.

The present invention also provides an embodiment of a quick-change system for an electric vehicle battery pack. Referring to FIG. 3 for details, the quick-change system includes a first battery pack 10, a second battery pack 20, and a switching unit. The two battery packs 20 can be independently used as power sources and are arranged on the electric vehicle. The output end of the first battery pack 10 and the output end of the second battery pack 20 are connected in parallel. The switching unit is configured to: switch to the second battery pack 20 for power supply when the SOC of the first battery pack 10 currently supplying power is less than a predetermined threshold. The predetermined threshold can be set according to the minimum output power of the battery pack or according to avoiding damage to the battery due to exhaustion of the battery pack. Generally, the predetermined threshold is set between 5% and 8%.

The electric vehicle is equipped with two power sources, and the two power sources are connected in parallel. When the power of one power source (the first battery pack is generally the priority power source) is too low, switch to another power source (the second battery pack is generally the priority power source). Standby power supply) work, which can effectively increase the mileage of electric vehicles.

Considering the rapid replacement and charging of battery packs, both the first battery pack 10 and the second battery pack 20 include a plurality of modules 30 that can be disassembled separately, and each module 30 can be charged separately in a household electricity environment. Referring to the schematic structural diagram of the first battery pack 10 shown in FIG. 6, since the second battery pack has the same structure as the internal module 30 of the first battery pack, the structure of the second battery pack is not shown, but refer to Figure 6 shows.

Both the first battery pack 10 and the second battery pack 20 are composed of n (n ≥ 1, and an integer) modules 30, and the modules 30 are connected to the battery case through a quick connector, which is convenient for quick replacement of the modules. The weight of each module 30 ensures that adults can move and replace normally. Each module 30 can be charged independently at home, which is convenient, fast and safe.

Referring to FIG. 4 , a first main positive relay 11 is provided on the internal wiring of the output end of the first battery pack 10 , and the first main positive relay 11 is connected with a first diode 12 in parallel. Referring to FIG. 5 , a second main positive relay 21 is provided on the internal wiring of the output end of the second battery pack 20 , and the second main positive relay 21 is connected in parallel with a second diode 22 . During normal driving, the first battery pack 10 is generally used for power supply, and when the first battery pack 10 is used for power supply, the first main positive relay 11 is closed and the second main positive relay 21 is open.

The switching unit in this embodiment is used to control the electric vehicle, but the driving state of the electric vehicle also needs to be considered. Therefore, under the condition that the electric vehicle is in the driving state, the switching unit is specifically configured as follows: the first main positive relay 11 is disconnected, the first battery pack 10 supplies power to the outside through the first diode 12; the second main positive relay 21 is closed, the second battery pack 20 supplies power to the outside through the second main positive relay 21; under the condition that the voltage of the second battery pack 20 is greater than the voltage of the first battery pack 10, the unidirectional first diode 12 is disconnected .

When the electric vehicle is in a parked state, the switching unit is specifically configured to: enable the low-voltage system of the first battery pack 10 to enter a sleep mode through the gateway controller, and activate the low-voltage system of the second battery pack 20 during the restart process of the electric vehicle. The system is also prohibited from starting the low-voltage system of the first battery pack 10 , so that only the second battery pack 20 supplies power.

Operation switching: when the first battery pack 10 needs to be switched to the second battery pack 20, the first main positive relay 11 of the first battery pack 10 is controlled to be disconnected, and at this time, the first diode 12 is turned on for external power supply , the next step is to close the second main positive relay 21 of the second battery pack 20. At this time, the two battery packs supply power to the outside at the same time, but because the voltage of the second battery pack 20 is higher than that of the first battery pack 10, the first diode 12 Reverse cut-off, no voltage output, no voltage mutation and potential difference between the two battery packs, and the gateway controller makes the low-voltage system of the first battery pack 10 enter the sleep mode, and the switching is successfully completed.

Parking switch: when the SOC of the first battery pack 10 is too low, after parking, the gateway controller will make the low-voltage system of the first battery pack 10 enter the dormant mode, and only start the electrical system of the second battery pack 20 when restarting, complete switch.

Each battery pack contains n (n≥1, and an integer) battery system acquisition boards LECU and a battery system main control board BMU. Among them, the acquisition board mainly collects the voltage and temperature of each single battery; the main control board of the battery system mainly communicates with the peripheral units of the battery system.

The main control board of the battery system controls the relay inside the battery pack to turn on or off through the signal, and monitors the voltage between the total positive and the total negative at the same time. The main control board of the battery system collects the current detected by the current sensor from time to time as one of the main basis for calculating SOC. The main control board of the battery system detects the on and off status of the relay as a safety monitoring condition. The main control board of the battery system outputs control signals to control loads such as fans in the battery pack.

So far, those skilled in the art should appreciate that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, the disclosed embodiments of the present invention can still be used. Many other variations or modifications consistent with the principles of the invention are directly identified or derived from the content. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (7)

1. a kind of quick change method of battery of electric vehicle bag is it is characterised in that include:

In electric motor car, configuration being capable of independently the first battery bag as electrical source of power and the second battery bag；

The outfan of the outfan of described first battery bag and described second battery bag is connected in parallel；

When the charging capacity of the first battery bag of current power supply is less than predetermined threshold with the ratio of rated capacity, it is switched to described Second battery bag is powered；

Wherein, the outlet internal line of described first battery bag is provided with the first main positive relay, described first master just continues Electrical equipment parallel connection the first diode；Second main positive relay is provided with the outlet internal line of described second battery bag, described Second master positive relay parallel connection the second diode；When described first battery bag is powered, the described first main positive relay closes Close, the described second main positive relay disconnects；

Wherein, under conditions of described electric motor car is in transport condition, described it is switched to what described second battery bag was powered Step includes: the described first main positive relay disconnects, and described first battery bag passes through described first diode supplying power for outside；Described Second master positive relay closure, described second battery bag passes through the described second main positive relay supplying power for outside；In the described second electricity Under conditions of the voltage of Chi Bao is more than the voltage of described first battery bag, described first diode of one-way conduction disconnects.

2. quick change method according to claim 1 it is characterised in that

Described first battery bag and described second battery bag all include multiple modules that can individually dismantle, each described module energy Enough individually charged under family's power utilization environment.

3. quick change method according to claim 1 it is characterised in that one-way conduction described first diode disconnect After step, also include: park mode is entered by the low-pressure system that gateway controller makes described first battery bag.

4. quick change method according to claim 1 it is characterised in that be in the condition of dead ship condition in described electric motor car Under, described it is switched to the step that described second battery bag is powered and includes:

Park mode is entered by the low-pressure system that gateway controller makes described first battery bag, again opens in described electric motor car Start the low-pressure system of described second battery bag and the low-pressure system of the first battery bag described in No starting during dynamic, thus Only powered by described second battery bag.

5. a kind of quick-change system of battery of electric vehicle bag is it is characterised in that include:

Can independently the first battery bag as electrical source of power and the second battery bag, configuration in electric motor car, described first The outfan of the outfan of battery bag and described second battery bag is connected in parallel；

Switch unit, is used for: is less than predetermined threshold in the charging capacity of the first battery bag and the ratio of rated capacity of current power supply During value, it is switched to described second battery bag and is powered；

Wherein, the outlet internal line of described first battery bag is provided with the first main positive relay, described first master just continues Electrical equipment parallel connection the first diode；Second main positive relay is provided with the outlet internal line of described second battery bag, described Second master positive relay parallel connection the second diode；When described first battery bag is powered, the described first main positive relay closes Close, the described second main positive relay disconnects；

Wherein, under conditions of described electric motor car is in transport condition, described switch unit specifically for: make described first main just Relay disconnects, and described first battery bag passes through described first diode supplying power for outside；Make the positive relay closure of described second master, Described second battery bag passes through the described second main positive relay supplying power for outside；It is more than described the in the voltage of described second battery bag Under conditions of the voltage of one battery bag, described first diode of one-way conduction disconnects.

6. quick-change system according to claim 5 it is characterised in that

Described first battery bag and described second battery bag all include multiple modules that can individually dismantle, each described module energy Enough individually charged under family's power utilization environment.

7. quick-change system according to claim 5 it is characterised in that

Under conditions of described electric motor car is in dead ship condition, described switch unit specifically for: by gateway controller so that The low-pressure system of described first battery bag enters park mode, starts described second electricity in described electric motor car restarting procedure The low-pressure system of the first battery bag described in the low-pressure system of Chi Bao and No starting, thus only supplied by described second battery bag Electricity.