CN214775407U

CN214775407U - Electric automobile battery pack electrical framework capable of being charged quickly

Info

Publication number: CN214775407U
Application number: CN201822007319.3U
Authority: CN
Inventors: 张朝辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-12-01
Filing date: 2018-12-01
Publication date: 2021-11-19
Anticipated expiration: 2028-12-01

Abstract

The utility model relates to an electric automobile battery pack electrical framework that can quick charge, fill the interface soon including cell, charge switch, discharge switch, direct current bus, on-vehicle unit such as charging and direct current. The 3 charge switches and the 4 discharge switches are all electric switches. The method is characterized in that: the battery unit is provided with two battery modules, the vehicle-mounted charging unit is provided with two vehicle-mounted charging ports, and the direct current bus unit is provided with two groups of direct current buses; the discharging switch is used for switching off the charging switch to be conducted, the two battery modules are connected in series, and the direct-current quick charging interface is used for high-voltage charging; the charging switch is used for switching off and switching on the discharging switch, the two battery modules are separated, and two groups of direct current buses (connected in common or independent or in parallel) are used for low-voltage discharging; after parking, the discharging switch and the charging switch are turned off, and the two battery modules can be charged at a low speed through the two vehicle-mounted charging ports. The advantages are as follows: 1. high-voltage quick charging in series connection and low-voltage safe discharging in a discrete mode; 2. the electric energy redundancy and the power supply redundancy are convenient for driving redundancy, and the active balance is achieved.

Description

Electric automobile battery pack electrical framework capable of being charged quickly

Technical Field

The utility model relates to an electric automobile group battery electrical framework that can quick charge belongs to electric automobile technical field.

Background

Two major key components of an electric vehicle are a battery system and a power system. The battery system comprises a battery pack, an electrical switch and a Battery Management System (BMS); the power system comprises a motor, a motor driver, a speed reducer and the like. The power system of the electric automobile is mainly divided into three types according to the different numbers of the adopted motors: single motor system, bi-motor system, four motor systems.

Most of the existing battery systems of electric vehicles are provided with a battery pack. The battery pack adopts an integral electrical framework, namely, the charging and the discharging are the same bus voltage, and the switching control of the charging and the discharging is realized by an electrical switch. At present, the mainstream battery used by the electric vehicle is a lithium ion battery, and the lithium ion battery mainly includes two types of electric cores, namely ternary lithium and lithium iron phosphate. A large number of battery cells are combined into a matrix structure in parallel-series connection, namely, a plurality of battery cells are firstly connected into a single battery cell with the required Ah capacity in parallel, and then a plurality of single battery cells are connected into a battery pack with the required kWh capacity in series. The Battery Management System (BMS) functions as: collecting parameters such as voltage, current and temperature of a battery core, transmitting and storing data, estimating battery capacity, overcharge/overdischarge/overload protection, charge and discharge control, balance control, insulation detection and thermal management, and communicating data with a vehicle control unit, a motor controller and a charging pile.

According to the national standard GB/T31466-2015 voltage class of the high-voltage system of the electric automobile, the battery system can adopt six nominal voltage classes: 144V, 288V, 317V, 346V, 400V and 576V. Accordingly, the national standard "GB/T18488.1-2015 drive motor system for electric vehicles" states that the dc bus voltage of the motor system takes the following classes: 36V, 48V, 60V, 80V, 120V and 144V^*、168V、192V、216V、240V、264V、288V^*、312V^*、336V^*、360V、384V^*408V, 540V, 600V, 650V, 700V, 750V (marked with a preferred rating). Meanwhile, in the national standard GB/T18487.1-2015 electric vehicle conduction charging system, four DC charging voltage levels are given: 200-500V, 350-700V, 500-950V and above 950V (determined by negotiation between vehicle manufacturers and power supply equipment manufacturers).

According to relevant statistics, relatively speaking, the battery voltage of the electric commercial vehicle is higher than that of the electric passenger vehicle, and the battery voltage of later-stage production is higher than that of the former-stage production; has crossed from the initial 300V to 800V; the battery voltage of electric vehicles of different manufacturers or different models of the same manufacturer is different. Power systems approaching 800V are used primarily in electric trucks and buses. Recently, international famous car enterprises have successively launched passenger cars of 800V systems, such as: benz project one, Porsche 919Hybrid and Mission, Audi AICON, Corneseger Regera, E Motion of Fisker, and the like.

The direct current charging pile is also the same, namely the output voltage of later construction is higher than the output voltage compatible with the earlier construction; the former is from 200V to 500V, the latter is from 200V to 750V, and the future develops 950V and higher.

Two main factors influencing the development of electric automobiles are endurance mileage and charging time, and the first problem (endurance mileage) has been solved (the energy/power density of the battery cell has been greatly improved, the capacity of the battery pack can meet about 400km endurance mileage; and companies such as Ningshi generation have mass-produced high-rate charged battery cells). The only problem to be solved is the fast charging, which becomes the focus of even the new round of technology competition in China and foreign countries.

Recently, charging standards are jointly established in the middle of the day to achieve high-power charging. The main technical indexes of high-power charging are preliminarily provided, the charging voltage is 800V-1000V, the charging current is 125A-250A under the working condition without cooling, and the charging power is more than or equal to 120 kW; the charging current is 400-500A under the working condition of cooling, and the charging power is more than or equal to 320 kW. From the aspect of technical standards, the high-power charging has a clear boundary, i.e. the charging current standard is defined to be about 250A. European and American enterprises plan to realize high-power charging of more than 150kW before and after 2018 and realize high-power charging of 350kW and more than 2020.

Therefore, the development goal of the direct-current high-power charging of the electric automobile is a technology of charging the battery pack in a single gun conduction mode, wherein the charging power is 350kW or more, and 80-90% of electricity is charged in 10-15 minutes. Then, the electric vehicle raises the battery pack voltage for the purpose of quick charging. Although the 800V power system can realize quick charging, the defects are also obvious: first, the insulation problem is a challenge; furthermore, the increase in voltage causes the motor and electrical components to increase in volume (e.g., the motor drive may increase in volume by 10%); thirdly, this is an entirely new concept for passenger cars, all core components need to be redesigned; moreover, there are fewer enterprises that can provide 800V related components and parts, and the industry chain needs to be re-developed.

In short, such a wide range of battery voltages tends to increase in voltage, which brings about a great risk to the insulation safety of electric vehicles, and brings about great disadvantages to the development and standardization of core components such as drivers and motors, and the development of the entire industrial chain. Meanwhile, the charging efficiency, the design, the mutual compatibility, the development and the construction, the operation and the maintenance of the charging pile are also seriously influenced.

In summary, the development of the electric automobile industry relies on three core technologies, and requires the coordinated compatibility and synchronous development of the charging technology and the facility construction. How to solve the problems of quick charging and insulation safety of the electric automobile, solve the situation that car enterprises, pile enterprises and charging facility construction units cannot standardize collaborative development, promote the benign development of an industrial chain, and be a key problem for realizing curve overtaking of the electric automobile and moving to the automobile strong country in China.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the defects of the prior art, designing an electric automobile battery pack electric framework capable of being charged quickly, and satisfactorily solving the problems of quick charging and safe operation of the electric automobile, the development problem of an industrial chain and the coordination and compatibility of the electric automobile and a charging pile; the system can be generally suitable for series of electric passenger vehicles and commercial vehicles and is generally used for single-motor and multi-motor topologies; the unified and standardized (battery/drive/motor/charging) voltage platform conforms to the existing relevant national standards, so as to become the industry standard and the national standard of the electric framework of the battery pack of the electric automobile.

The technical scheme of the utility model as follows:

an electric automobile battery pack electrical framework capable of being charged quickly is composed of a battery unit (1), a charging switch unit (2), a discharging switch unit (3), a direct current bus unit (4), a vehicle-mounted charging unit (5) and a direct current quick charging interface (6). The charging switch unit (2) comprises three switches, namely a switch K01, a switch K02 and a switch K03, and the discharging switch unit (3) comprises four switches, namely a switch K11, a switch K12, a switch K21 and a switch K22; the switches K01, K02, K03, K11, K12, K21, and K22 are all electrical switches that employ dc contactors having two electrical terminals, referred to as front and back terminals (if one terminal is referred to as a front terminal, the other terminal is referred to as a back terminal, so called for convenience of description). The method is characterized in that:

battery unit (1) has 2 battery modules, battery module A and battery module B promptly, and two battery modules have the same electric core model, cluster number and capacity. The direct current bus unit (4) is provided with two groups of direct current buses, namely a direct current bus A and a direct current bus B. The vehicle-mounted charging unit (5) has 2 vehicle-mounted charging ports, namely a vehicle-mounted charging port A and a vehicle-mounted charging port B. The connection relationship is as follows: the positive pole and the negative pole of battery module A connect the anodal and the negative pole of on-vehicle mouth A that charges respectively, and the anodal and the negative pole of battery module B connect the anodal and the negative pole of on-vehicle mouth B that charges respectively. The positive electrode of the battery module A is connected with the rear end of the switch K01, and the front end of the switch K01 is connected with the positive electrode of the direct-current quick-charging interface (6); the negative electrode of the battery module A is connected with the front end of the switch K03, and the rear end of the switch K03 is connected with the positive electrode of the battery module B; the negative pole of battery module B connects the front end of switch K02, and the rear end of switch K02 connects the negative pole of direct current quick charge interface (6). The positive electrode of the battery module A is connected with the front end of a switch K11, and the rear end of a switch K11 is connected with the positive electrode of a direct current bus A; the negative electrode of the battery module a is connected to the front end of the switch K12, and the rear end of the switch K12 is connected to the negative electrode of the dc bus a. The positive electrode of the battery module B is connected with the front end of a switch K21, and the rear end of a switch K21 is connected with the positive electrode of a direct current bus B; the negative electrode of the battery module B is connected to the front end of the switch K22, and the rear end of the switch K22 is connected to the negative electrode of the dc bus B. The direct current bus A and the direct current bus B have three kinds of interrelations: the first is independent, namely the direct current bus A is not directly electrically connected with the direct current bus B; the second is common ground, namely the negative electrode of the direct current bus A is connected with the negative electrode of the direct current bus B, and the positive electrode of the direct current bus A is not connected with the positive electrode of the direct current bus B; the third is parallel connection, that is, the negative electrode of the direct current bus A is connected with the negative electrode of the direct current bus B, and the positive electrode of the direct current bus A is connected with the positive electrode of the direct current bus B.

The vehicle-mounted charging unit (5) is used for a vehicle-mounted charger to charge the battery unit (1) at a low speed. The direct-current quick charging interface (6) is used for quickly charging the battery unit (1) through the direct-current charging pile. The charging switch unit (2) and the discharging switch unit (3) are used for switching control and on-off control of the charging and discharging states of the battery unit (1). The direct current bus A and the direct current bus B of the direct current bus unit (4) can respectively carry 1 or 2 motor drivers. When 2 motor drivers are loaded respectively, the four-motor power system is suitable for the four-motor power system. When the motor drivers are respectively loaded with 1 motor, the motor driver is suitable for a double-motor power system and a single-motor power system; for a single motor power system, two motor drivers may drive one motor in parallel, or "jointly" drive a dual three-phase or six-phase motor (i.e., each motor driver drives a set of three-phase windings). If the special condition that two groups of direct current buses are connected in parallel is adopted, 1 or 2 or 4 motor drivers can be loaded together, and the motor drivers are respectively suitable for single-motor, double-motor and four-motor power systems.

When the electric automobile is in a running state, the three switches of the charging switch unit (2) are turned off, the four switches of the discharging switch unit (3) are turned on, the two battery modules of the battery unit (1) are separated, and power is supplied by the two groups of direct current buses in a relatively low voltage mode (namely, the voltage of the battery modules) in an independent or common ground or parallel connection mode. Therefore, the electric insulation is conveniently realized, and the operation safety is improved. And electric energy redundancy and power supply redundancy can be realized, and the operation reliability is improved. By adjusting the output power difference (or working in a time-sharing manner) of the motor drivers on the two direct current buses, active balance of the two battery modules in the discharging process can be realized.

When the electric automobile is in a quick charging state, the four switches of the discharging switch unit (3) are turned off, the three switches of the charging switch unit (2) are turned on, the two battery modules of the battery unit (1) are connected in series, and the direct-current quick charging interface (6) is used for charging at a relatively high voltage (namely 2 times of the voltage of the battery modules). Therefore, the charging power is doubled for the same charging current. When the electric automobile is in a slow charging state, the switches of the charging switch unit (2) and the discharging switch unit (3) are all turned off, and the two battery modules are independently charged at a low speed through the two vehicle-mounted charging ports. By adjusting the charging power difference value of the two vehicle-mounted charging ports, active balance of the two battery modules in the slow charging process can be achieved.

When the electric automobile is in a parking state, the four switches of the discharging switch unit (3) and the three switches of the charging switch unit (2) are all turned off, and the two battery modules are completely and independently isolated, so that the electrical safety is realized.

The nominal voltage of the battery module of the battery unit (1) can be preferably 400V recommended by national standard GB/T31466-2015; direct current bus voltage level 384V recommended by corresponding national standard GB/T18488.1-2015^*And 408V. Accordingly, the motor driver can be designed by adopting the most mature and universal 600-650V power semiconductor device. When the battery modules are charged in series, the nominal voltage value is 800V, the requirement of a high-power charging voltage platform is met, and the DC charging voltage level is 500-950V corresponding to the national standard GB/T18487.1-2015. Aiming at the electrical architecture, the output voltage grade of the high-power direct-current charging pile is 500V-950V, high-efficiency and quick charging is facilitated, and the universality and the standardization degree of the charging pile are improved.

The electric framework is generally suitable for series of electric passenger vehicles and commercial vehicles and is generally applied to single-motor and multi-motor power systems. The motor can be an alternating current asynchronous motor, a permanent magnet synchronous motor or other novel motors.

Compared with the prior art, the utility model has the following superiority:

1. the electrical architecture employs battery modules with "series charging, discrete discharging". The double advantages of quick charging (relatively high voltage) and standard power supply (relatively low voltage) are achieved; the high-power charging device can realize high-speed and high-efficiency high-power charging and can improve the electrical safety and reliability.

2. The electrical architecture realizes electric energy redundancy and power supply redundancy, and is convenient for driving redundancy; active balance among the battery modules can be realized.

3. The electrical architecture enables uniform and standardized (battery/drive/motor/charge) voltage platforms. Based on mature devices, technologies and insulation requirements, the standardization and serialization of battery packs, drivers, motors and power platforms are facilitated.

4. The electric framework is generally suitable for series of electric passenger vehicles and commercial vehicles and is generally used for single-motor and multi-motor topologies. The problem of electric automobile quick charge and safe operation has satisfactorily been solved, the problem of electric automobile and the coordinated development of electric pile has been solved. The method is beneficial to the development of the existing industrial chain, and can become the industrial standard and the national standard of the electric framework of the battery pack of the electric automobile.

Drawings

Fig. 1 is an electrical architecture diagram of a conventional electric vehicle battery pack. The voltage plateaus for charging and discharging the single battery pack are the same.

Fig. 2 is an electrical architecture diagram of a fast-charging electric vehicle battery pack. The battery modules are charged in series and discharged independently.

Fig. 3 is an electrical architecture diagram of a fast-charging electric vehicle battery pack. The battery modules are charged in series and discharged in common.

Fig. 4 is an electrical architecture diagram of a fast-charging electric vehicle battery pack. The battery modules are charged in series and discharged in parallel.

In the figure, 1 is a battery unit, 2 is a charging switch unit, 3 is a discharging switch unit, 4 is a direct current bus unit, 5 is an on-vehicle charging unit, and 6 is a direct current quick charging interface.

Detailed Description

The present invention will be described in detail with reference to the following preferred embodiments in conjunction with the accompanying drawings.

As shown in fig. 2 to 4, an electric vehicle battery pack electrical architecture capable of being charged quickly is composed of a battery unit (1), a charging switch unit (2), a discharging switch unit (3), a dc bus unit (4), a vehicle-mounted charging unit (5) and a dc quick charging interface (6). The charging switch unit (2) comprises three switches, namely a switch K01, a switch K02 and a switch K03, and the discharging switch unit (3) comprises four switches, namely a switch K11, a switch K12, a switch K21 and a switch K22; the switches K01, K02, K03, K11, K12, K21, and K22 are all electrical switches that employ dc contactors having two electrical terminals, referred to as front and back terminals for ease of description. The method is characterized in that:

battery unit (1) has 2 battery modules, battery module A and battery module B promptly, and two battery modules have the same electric core model, cluster number and capacity. The direct current bus unit (4) is provided with two groups of direct current buses, namely a direct current bus A and a direct current bus B. The vehicle-mounted charging unit (5) has 2 vehicle-mounted charging ports, namely a vehicle-mounted charging port A and a vehicle-mounted charging port B. The connection relationship is as follows: the positive pole and the negative pole of battery module A connect the anodal and the negative pole of on-vehicle mouth A that charges respectively, and the anodal and the negative pole of battery module B connect the anodal and the negative pole of on-vehicle mouth B that charges respectively. The positive electrode of the battery module A is connected with the rear end of the switch K01, and the front end of the switch K01 is connected with the positive electrode of the direct-current quick-charging interface (6); the negative electrode of the battery module A is connected with the front end of the switch K03, and the rear end of the switch K03 is connected with the positive electrode of the battery module B; the negative pole of battery module B connects the front end of switch K02, and the rear end of switch K02 connects the negative pole of direct current quick charge interface (6). The positive electrode of the battery module A is connected with the front end of a switch K11, and the rear end of a switch K11 is connected with the positive electrode of a direct current bus A; the negative electrode of the battery module a is connected to the front end of the switch K12, and the rear end of the switch K12 is connected to the negative electrode of the dc bus a. The positive electrode of the battery module B is connected with the front end of a switch K21, and the rear end of a switch K21 is connected with the positive electrode of a direct current bus B; the negative electrode of the battery module B is connected to the front end of the switch K22, and the rear end of the switch K22 is connected to the negative electrode of the dc bus B. The direct current bus A and the direct current bus B have three kinds of interrelations: the first is independent (as in fig. 2), i.e. the dc bus a is not directly electrically connected to the dc bus B; the second is common ground (as shown in fig. 3), i.e., the negative electrode of the dc bus a is connected with the negative electrode of the dc bus B, and the positive electrode of the dc bus a is not connected with the positive electrode of the dc bus B; the third is parallel connection (as shown in fig. 4), i.e. the negative electrode of the dc bus a is connected with the negative electrode of the dc bus B, and the positive electrode of the dc bus a is connected with the positive electrode of the dc bus B.

When the electric automobile is in a driving state, the three switches of the charging switch unit (2) are turned off, the four switches of the discharging switch unit (3) are turned on, the two battery modules of the battery unit (1) are separated, and power is supplied at relatively low voltage (namely battery module voltage) in an independent (as shown in fig. 2) or common ground (as shown in fig. 3) or parallel connection (as shown in fig. 4) mode through two groups of direct current buses respectively. Therefore, the electric insulation is conveniently realized, and the operation safety is improved. And electric energy redundancy and power supply redundancy can be realized, and the operation reliability is improved. By adjusting the output power difference (or working in a time-sharing manner) of the motor drivers on the two direct current buses, active balance of the two battery modules in the discharging process can be realized.

The nominal voltage of the battery module of the battery unit (1) can be preferably 400V recommended by national standard GB/T31466-2015; direct current bus voltage level 384V recommended by corresponding national standard GB/T18488.1-2015^*、408V。Accordingly, the motor driver can be designed by adopting the most mature and universal 600-650V power semiconductor device. When the battery modules are charged in series, the nominal voltage value is 800V, the requirement of a high-power charging voltage platform is met, and the DC charging voltage level is 500-950V corresponding to the national standard GB/T18487.1-2015. Aiming at the electrical architecture, the output voltage grade of the high-power direct-current charging pile is 500V-950V, high-efficiency and quick charging is facilitated, and the universality and the standardization degree of the charging pile are improved.

Design example of battery module: if a ternary lithium ion battery cell (nominal voltage of 3.7V and voltage range of 2.8V-4.25V) is selected, 108 (or 112) battery cells are connected in series in the battery module, and the nominal voltage is 400V (or 410V); if a lithium iron phosphate battery cell (nominal voltage of 3.2V, voltage range of 2.5V-3.65V) is selected, 126 (or 128) battery cells are connected in series in the battery module, and the nominal voltage is 400V (or 410V).

Claims

1. An electric automobile battery pack electrical framework capable of being charged quickly is composed of a battery unit (1), a charging switch unit (2), a discharging switch unit (3), a direct current bus unit (4), a vehicle-mounted charging unit (5) and a direct current quick charging interface (6); the charging switch unit (2) comprises a switch K01, a switch K02 and a switch K03, and the discharging switch unit (3) comprises a switch K11, a switch K12, a switch K21 and a switch K22; the switch K01, the switch K02, the switch K03, the switch K11, the switch K12, the switch K21 and the switch K22 are all electric switches, a direct current contactor is adopted, and the electric switches are provided with two electric terminals which are called as a front end and a rear end for convenience of description;

the method is characterized in that: the battery unit (1) is provided with 2 battery modules, namely a battery module A and a battery module B, wherein the two battery modules have the same cell model, string number and capacity; the direct current bus unit (4) is provided with two groups of direct current buses, namely a direct current bus A and a direct current bus B; the vehicle-mounted charging unit (5) is provided with 2 vehicle-mounted charging ports, namely a vehicle-mounted charging port A and a vehicle-mounted charging port B; the connection relationship is as follows: the positive electrode and the negative electrode of the battery module A are respectively connected with the positive electrode and the negative electrode of the vehicle-mounted charging port A, and the positive electrode and the negative electrode of the battery module B are respectively connected with the positive electrode and the negative electrode of the vehicle-mounted charging port B; the positive electrode of the battery module A is connected with the rear end of the switch K01, and the front end of the switch K01 is connected with the positive electrode of the direct-current quick-charging interface (6); the negative electrode of the battery module A is connected with the front end of the switch K03, and the rear end of the switch K03 is connected with the positive electrode of the battery module B; the negative electrode of the battery module B is connected with the front end of a switch K02, and the rear end of a switch K02 is connected with the negative electrode of the direct-current quick-charging interface (6); the positive electrode of the battery module A is connected with the front end of a switch K11, and the rear end of a switch K11 is connected with the positive electrode of a direct current bus A; the negative electrode of the battery module A is connected with the front end of a switch K12, and the rear end of a switch K12 is connected with the negative electrode of the direct current bus A; the positive electrode of the battery module B is connected with the front end of a switch K21, and the rear end of a switch K21 is connected with the positive electrode of a direct current bus B; the negative electrode of the battery module B is connected with the front end of a switch K22, and the rear end of a switch K22 is connected with the negative electrode of a direct current bus B; the direct current bus A and the direct current bus B have three kinds of interrelations: the first is independent, namely the direct current bus A is not directly electrically connected with the direct current bus B; the second is common ground, namely the negative electrode of the direct current bus A is connected with the negative electrode of the direct current bus B, and the positive electrode of the direct current bus A is not connected with the positive electrode of the direct current bus B; the third is parallel connection, that is, the negative electrode of the direct current bus A is connected with the negative electrode of the direct current bus B, and the positive electrode of the direct current bus A is connected with the positive electrode of the direct current bus B.