WO2020103273A1

WO2020103273A1 - Battery pack having quick charging function and quick charging method

Info

Publication number: WO2020103273A1
Application number: PCT/CN2018/123075
Authority: WO
Inventors: 刘贵生; 丁浩; 刘志钢; 姚亮; 孙鹏; 李秋影
Original assignee: 北斗航天汽车（北京）有限公司
Priority date: 2018-11-23
Filing date: 2018-12-24
Publication date: 2020-05-28
Also published as: CN109193881A

Abstract

The present invention relates to the technical field of quick charging devices for battery packs, and more particularly to a battery pack having a quick charging function and a quick charging method. Said battery pack comprises a plurality of battery cells, a plurality of discharging relays for connecting the battery cells in parallel, and a plurality of charging relays for connecting the battery cells in series. According to the battery pack having a quick charging function and the quick charging method disclosed in the present invention, the charging relays and the discharging relays are provided to achieve discharging of the battery pack with battery cells connected in parallel, and charging of the battery pack with battery cells connected in series, so that the charging voltage can be boosted and the charging time can be reduced, achieving the purpose of quick charging, and increasing the charging speed without increasing heat generation and heat loss; in addition, with the charging power unchanged, boosting the voltage can reduce the current, reducing heat loss; and furthermore, no complex electronic device needs to be inputted, reducing the cost of the battery pack.

Description

Battery pack with fast charging function and fast charging method

Technical field

The invention relates to the technical field of a fast charging device for a battery pack, in particular to a battery pack with a fast charging function and a fast charging method.

Background technique

In recent years, pure electric vehicles have made great progress. In the country and the world, various countries and enterprises are vigorously developing and promoting pure electric vehicles. As the energy output mechanism of pure electric vehicles, the important role of the battery pack is self-evident.

For an electric vehicle to have a long driving range, the battery pack needs to have a large amount of electricity. However, when the amount of electricity increases, the corresponding charging time will be prolonged, and the longer charging time is unbearable. (Lithium titanate battery) can achieve fast charging, but such batteries have high cost, low energy density, and lack of universality; if you want to charge quickly, you will need a larger current, which will directly increase the heat loss, thus As a result, the charging efficiency of the battery pack is low, and at the same time, the safety is reduced, and even an explosion may occur, endangering personal safety.

In summary, how to solve the fast charging ability of the battery pack, reduce heat loss, and improve charging efficiency at the same time is an important breakthrough point for the pure electric vehicle to achieve long driving mileage and enter thousands of households.

Therefore, in order to solve the above problems, there is an urgent need to invent a new battery pack with a fast charging function and a fast charging method.

Summary of the invention

The purpose of the present invention is to provide a battery pack with a fast charging function and a fast charging method. Through the design of the module arrangement and connection structure, it can be multiplied without changing the performance of the battery cell and in a safe and effective mode Charge rate.

The present invention provides the following solutions:

A battery pack with a fast charging function includes a plurality of battery cells, each of which includes a plurality of cells in series; both ends of each battery cell are connected to a discharge relay; two adjacent cells The connection points of the battery unit are connected through a charging relay; the discharging relay and the charging relay are both connected with a battery manager, and are used to control the on-off of the discharging relay and the charging relay.

Preferably, the battery pack with a fast charging function further includes an overload protector, and the overload protector is connected in series at the junction of two adjacent battery cells.

Preferably, the overload protector is also connected in series at the end of the two discharge relays.

Preferably, the overload protector and the charging relay are connected by a copper cable.

Preferably, each of the battery cells is electrically connected through a conductive copper bar.

Preferably, each of the discharge relays and each of the charging relays are connected to the battery core through copper cables, respectively.

Preferably, the battery pack with a fast charging function further includes a discharge output terminal, and the discharge output terminal is connected to both ends of each battery cell.

Preferably, the battery pack with fast charging function further includes a charging input terminal, and the charging input terminal is connected to the first end and the end of all the battery cells connected in series.

Preferably, the battery cell is any one of a ternary lithium battery cell and a lithium iron phosphate battery cell.

Further, the present invention also provides a method for quickly charging the battery pack with the battery pack with a fast charging function. In a discharging state, each of the discharge relays is closed, and each of the charging relays is open. , Each of the battery units is connected in parallel for external output of electrical energy; in the charging state, each of the charging relays are closed, each of the discharge relays are disconnected, and each of the battery units is connected in series in order, for each The battery unit is charged.

The beneficial effects produced by the present invention:

The battery pack with fast charging function disclosed by the present invention includes a plurality of battery cells, a plurality of discharge relays for connecting the battery cells in parallel, and a plurality of charging for connecting the battery cells in series A relay; the first ends of two adjacent battery cells are electrically connected to both ends of one of the discharge relays respectively, and the second ends of two adjacent battery cells are respectively discharged with the other The two ends of the relay are electrically connected; one charging relay is connected in series between the first end of one of the two battery cells and the second end of the other battery cell; The discharge relay and each of the charge relays are electrically connected to the battery manager respectively; by setting the charge relay and the discharge relay, the battery pack is discharged in parallel and charged in series, so that the charging voltage can be increased and can Multiply increase the charging time to achieve the purpose of fast charging, that is, to increase the charging speed without increasing the current, without increasing the amount of heat, or increasing the heat loss; at the same time, with the charging power unchanged, the voltage can be reduced The current reduces heat loss; furthermore, the physical structure is used to achieve fast boost charging, the structure is simple, the cost is low, no complicated electronic equipment is required, and the use cost of the battery pack is reduced.

BRIEF DESCRIPTION

1 is a structural block diagram of a battery pack with fast charging function of the present invention;

2 is a structural block diagram (discharge state) of a battery pack with a fast charging function of the present invention;

3 is a structural block diagram (charging state) of a battery pack with fast charging function of the present invention;

4 is a structural block diagram of a battery pack with a fast charging function of the present invention (with an overload protector);

FIG. 5 is a flowchart of a method for quickly charging a battery pack of the present invention.

detailed description

The technical solutions of the present invention will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, just to facilitate the description of the present invention and simplify the description, rather than to indicate or imply that the device or element referred to must have a specific orientation, a specific orientation The construction and operation cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable Connected, or connected integrally; either mechanically or electrically; directly connected, or indirectly connected through an intermediary, or internally connected between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Referring to FIGS. 1 to 4, a battery pack with a fast charging function includes a plurality of battery cells, a plurality of discharge relays for connecting the battery cells in parallel, and a battery pack for connecting the battery cells A plurality of charging relays connected in series; the first ends of the two adjacent battery cells are electrically connected to the two ends of one discharge relay, and the second ends of the two adjacent battery cells are respectively Electrically connected to both ends of the other discharge relay; one of the two battery cells adjacent to each other is connected in series between the first end of the battery cell and the second end of the other battery cell The charging relay; each of the discharge relays and each of the charging relays are electrically connected to a battery manager, respectively. The battery unit includes a plurality of battery cells connected in series. Each of the battery cells is electrically connected through a conductive copper row. Each of the discharge relays and each of the charging relays is electrically connected to the battery cell through a copper cable, respectively. The battery cell is a ternary lithium battery cell.

The battery pack with fast charging function in this embodiment includes a plurality of battery cells, a plurality of discharge relays for connecting the battery cells in parallel, and a plurality of battery cells for connecting the battery cells in series Charging relay; the first ends of the two adjacent battery cells are electrically connected to the two ends of one discharge relay, and the second ends of the two adjacent battery cells are respectively connected to the other Two ends of the discharge relay are electrically connected; one of the two battery cells adjacent to each other is connected in series between the first end of the battery cell and the second end of the other battery cell; The discharge relay and each of the charge relays are electrically connected to the battery manager; by setting the charge relay and the discharge relay, the battery pack is discharged in parallel and charged in series, so that the charging voltage is increased, It can double the charging time to achieve the purpose of fast charging, that is, not to increase the charging speed by increasing the current, not to increase the amount of heat, and to increase the heat loss; at the same time, with the charging power unchanged, the voltage can be increased Reduce current and reduce heat loss; further, using physical structure to achieve boost fast charging, simple structure, low cost, without the need for complex electronic equipment investment, reducing the cost of battery packs.

As shown in FIG. 5, this embodiment also provides a method for quickly charging the battery pack with the battery pack with a fast charging function. In the discharge state, each of the discharge relays is closed, and each of the The charging relays are all disconnected, and each of the battery units is connected in parallel for external output of electric energy; in the charging state, each of the charging relays are closed, each of the discharging relays are disconnected, and each of the battery units is connected in series , For charging each of the battery cells.

The principle of the battery pack with a fast charging function described in this embodiment is: by increasing the voltage across the battery pack during charging, the purpose of achieving fast charging of the battery pack is achieved. When the battery pack is charged and discharged, there is a total power W, W = U × I, which is the voltage multiplied by the current. The total energy of the battery pack is E, the energy is equal to the power times the time, E = W × t = U × I × t. Under the condition that the total energy of the battery pack is unchanged, if the voltage can be increased by 3 times, the charging time can be shortened to 1/3, E = 3U × I × t / 3, and the fast charging function is realized for the battery pack . (3 times is just an example, not limited to 3 times, 2 times, 4 times can be used). As a chemical energy source, the battery cannot change the charge and discharge voltage arbitrarily during its use, so it is necessary to realize the voltage change in the process of multi-series series-parallel connection through a physical structure. At the same time, as the energy supply mechanism in the system, the discharge voltage of the battery pack generally has strict requirements (for example, the voltage requirement of the general plug-in hybrid car is 48V, the pure electric passenger parking space is 350V, and the pure electric passenger car is 650V).

The battery pack with fast charging function described in this embodiment gives an example to illustrate how to implement the present invention. To realize this fast charging function, basic modules are needed: main cable, several relays, several batteries, and conductive copper bars. The function of the total positive / negative cable is to output the energy of the battery pack in series and parallel connection; the battery is the basic unit that constitutes the battery pack; the copper bar is the conductive component of the two batteries in series; , The two ends of the relay are connected to the battery with copper cables. It includes 1 pair of total positive and total negative cables, 9 cell cores, 4 relays, and 6 copper bars. The rated parameters of the battery cell are 3V, 3Ah. In the discharge state, the 9-cell battery is divided into 3 groups, which are connected in parallel and connected in series. Then the battery pack is 3P3S (3 parallel 3 series). In the discharge state P1, the discharge relay is closed to form a path for charging The relay is open. At this time, the parameters of the battery pack are 9V and 9Ah. In this state, it takes 1h to charge the battery with the rated current (81Wh = 9V × 9A × 1h). In the charging state P2, the discharge relay is opened, and the charging relay is closed to form a path. At this time, the 9-cell batteries are all in a series state, then the battery pack changes to 1P9S (1 and 9 strings). The parameter is 27V, 3Ah, and the charging current can be completed in only 1 / 3h (81Wh = 27V × 9A × 1h / 3) with the charging current unchanged. Through this structural design, it is realized that the voltage is raised by an integer multiple of the time of charging without completing the discharge voltage platform of the cell pack, and the fast charging operation is completed.

In the battery pack with the fast charging function described in this embodiment, the present invention can reduce the heat loss during the charging process and improve the charging and discharging efficiency when the total charging power is unchanged. Including 1 pair of total positive and total negative cables, 9 batteries, 4 relays, 6 copper bars. The rated parameters of the battery are 3V, 3Ah. In the state P1, 9 batteries are divided into 3 groups, the groups are connected in parallel, and the groups are connected in series, the battery pack is 3P3S (3 and 3 strings), the discharge relay is closed to form a path, and the charge relay is opened. At this time, the parameters of the battery pack are 9V, 9Ah, which can be fully charged with a current of 9A for 1h (81Wh = 9V × 9A × 1h). In state P2, the discharge relay is opened and the charging relay is closed to form a path. At this time, all 9 batteries are in series state, then the battery pack changes to 1P9S. At this time, the parameter of the battery pack is 27V, 3Ah. In the case of constant power, only 3A can be used to complete the charging (81Wh = 27V × 3A × 1h). Comparing the heat loss in the P1 and P2 states, Q1 = I ₁ ² rt = 9 ² rt = 81rt Q2 = I ₂ ² rt = 3 ² rt = 9rt Q2 = 1 / 9Q1, in the P2 state the heat loss is in the P1 state 1/9 of this reduces the calorific value and improves the efficiency of charge and discharge (in this example, if the overall charge and discharge efficiency of the battery pack system is 98%, the charge and discharge efficiency will be increased to 98.88% after the high-voltage charging system is used)

The battery pack with fast charging function described in this embodiment is suitable for all kinds of batteries, no need to use a fast charging core, and adapts to the products currently on the market (ternary lithium, lithium iron phosphate batteries, etc.) Good; by increasing the charging voltage, the fast charging time can be doubled, and the effect is remarkable; the charging speed is not increased by increasing the current, the heat is not increased, and the heat loss is not increased; when the charging power is unchanged, the increase Voltage can reduce current and reduce heat loss (Q = I ² rt I drop makes Q drop); adopt physical structure to achieve boost fast charging, simple structure, low cost, without the need for complicated electronic equipment investment.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements do not deviate from the essence of the corresponding technical solutions of the technical solutions of the embodiments of the present invention range.

Claims

A battery pack with a fast charging function, characterized in that it includes a plurality of battery cells, each of which includes a plurality of battery cells connected in series; both ends of each battery cell are connected to a discharge relay; The two adjacent battery cells are connected by a charging relay end to end; the discharging relay and the charging relay are both connected to a battery manager, and are used to control the switching of the discharging relay and the charging relay.
The battery pack with a fast charging function according to claim 1, further comprising an overload protector, the overload protector connected in series at the junction of two adjacent battery cells.
The battery pack with a fast charging function according to claim 2, wherein the overload protector is also connected in series at the end of the two discharge relays.
The battery pack with fast charging function according to claim 3, wherein the overload protector and the charging relay are connected by a copper cable.
The battery pack with a fast charging function according to claim 4, wherein each of the battery cells is electrically connected through a conductive copper row.
The battery pack with fast charging function according to claim 5, characterized in that each of the discharge relays and each of the charging relays are respectively connected to the battery cells through a copper cable.
The battery pack with a fast charging function according to claim 6, further comprising a discharge output terminal, the discharge output terminal being connected to both ends of each battery cell.
The battery pack with fast charging function according to claim 7, further comprising a charging input terminal, the charging input terminal is connected to the first end and the end of all the battery cells connected in series.
The battery pack with a fast charging function according to claim 8, wherein the battery cell is any one of a ternary lithium battery cell and a lithium iron phosphate battery cell.
A battery pack rapid charging method for realizing a battery pack with a fast charging function according to any one of claims 1-9, characterized in that: in a discharging state, each of the discharge relays is closed, and each of the The charging relays are all disconnected, and the battery cells are all connected in parallel for external output of electric energy; in the charging state, each of the charging relays are closed, each of the discharging relays are disconnected, and the battery cells are connected in series , For charging each of the battery cells.