CN118219928A

CN118219928A - Power control method and device, multi-battery pack parallel system and vehicle

Info

Publication number: CN118219928A
Application number: CN202310961511.9A
Authority: CN
Inventors: 李涛; 谭志成; 张鑫; 郭名扬; 苏丹
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2023-07-31
Filing date: 2023-07-31
Publication date: 2024-06-21

Abstract

The invention discloses a power control method and a device thereof, a multi-battery parallel system and a vehicle, wherein the power control method comprises the following steps: receiving a voltage, a temperature and a state of charge value of each battery pack; determining a maximum discharge current or a maximum charge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery; and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system, so that the plurality of battery packs connected in parallel have larger charge and discharge power on the premise of meeting safety and reliability.

Description

Power control method and device, multi-battery pack parallel system and vehicle

Technical Field

The application relates to the technical field of batteries, in particular to a power control method and device, a multi-battery-pack parallel system and a vehicle.

Background

The multi-battery pack parallel system is generally applied to an electric driving scene such as but not limited to a trolley bus, an electric vehicle and the like, and can externally improve larger discharge current through a plurality of parallel battery packs, so that the multi-battery pack parallel system externally discharges with larger power to meet the power requirements of the electric vehicle and the trolley bus. However, in the multi-battery parallel system, the state of different battery packs has a larger or smaller difference, so that the discharging or charging capability of the different battery packs is different, and the whole multi-battery parallel system is influenced to discharge outwards. The battery management system of the existing multi-battery-pack parallel system cannot safely and reliably control the charging power and the discharging power of the multi-battery-pack parallel system.

Disclosure of Invention

The present application has been made in order to solve at least one of the above problems. According to a first aspect of the present application, there is provided a power control method of a multi-battery parallel system, the power control method comprising: receiving a voltage, a temperature and a state of charge value of each battery pack; determining a maximum discharge current or a maximum charge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery; and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system.

In one embodiment of the present application, when the multi-battery parallel system is in a discharge state, the method further comprises: determining a highest voltage of the multi-battery pack according to the voltage of each battery pack; and screening out all battery packs with the difference value within a preset difference value from the highest voltage to serve as the current discharging battery packs of the multi-battery pack parallel system.

In one embodiment of the present application, the determining the maximum discharge current of the multi-battery parallel system according to the temperature and the state of charge value of each of the battery packs includes: and determining the maximum discharge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery pack in the discharge battery packs.

In one embodiment of the present application, said determining a maximum discharge current of said multi-stack parallel system based on said temperature and said state of charge value of each of said discharged battery stacks comprises: screening out the highest temperature and the lowest temperature of all battery packs in the discharge battery packs; calculating the average value of the charge state values of all the battery packs in the discharge battery packs; and determining the maximum discharge current of the multi-battery parallel system according to the average value of the highest temperature, the lowest temperature and the state of charge value.

In one embodiment of the present application, the determining the maximum discharge current of the multi-battery parallel system according to the average value of the maximum temperature, the minimum temperature and the state of charge value includes: searching a first discharge current corresponding to the highest temperature and the average value of the charge state values based on a discharge ammeter of the charge state-temperature-allowable discharge current; searching a second discharge current corresponding to the lowest temperature and the average value of the charge state values based on the discharge ammeter of the charge state-temperature-allowable discharge current; and taking the minimum value of the first discharging current and the second discharging current as the maximum discharging current of the multi-battery-pack parallel system.

In one embodiment of the present application, determining a maximum charging current of the multi-battery parallel system according to the temperature and the state of charge value of each of the battery packs while the multi-battery parallel system is in a charged state includes: screening out the highest temperature and the lowest temperature of all the battery packs which are not fully charged in the multi-battery pack parallel system; calculating an average value of the state of charge values of all the battery packs which are not fully charged; and determining the maximum charging current of the multi-battery parallel system according to the average value of the highest temperature, the lowest temperature and the state of charge value.

In one embodiment of the present application, the determining the maximum charging current of the multi-battery parallel system according to the average value of the maximum temperature, the minimum temperature and the state of charge value includes: searching a first charging current corresponding to the highest temperature and the average value of the charge state values based on a charge state-temperature-charging current table allowing the charging current; searching a second charging current corresponding to the lowest temperature and the average value of the charge state values based on the charge state-temperature-charging current table allowing the charging current; and taking the minimum value of the first charging current and the second charging current as the maximum charging current of the multi-battery-pack parallel system.

In one embodiment of the present application, when the multi-battery parallel system is in a charged state, the power control method further includes: judging whether each battery pack is full or not according to the voltage and the state of charge value of each battery pack; and when the battery pack is full, after the maximum charging current value of the multi-battery pack parallel system is controlled to be not more than a preset threshold value, disconnecting the full battery pack from an external charger.

According to a second aspect of the present application, there is also provided a power control apparatus of a multi-battery parallel system, the power control apparatus comprising: the system comprises a storage medium and a processor, wherein the storage medium stores a computer program operated by the processor, and the computer program when being operated by the processor causes the processor to execute the power control method of any multi-battery parallel system.

According to a third aspect of the present application, there is also provided a battery management system main controller, which includes the power control device of any one of the above-mentioned multi-battery parallel systems.

According to a fourth aspect of the present application, there is also provided a multi-battery pack parallel system including: the battery management system comprises a plurality of battery packs, a plurality of battery management system auxiliary controllers and any one of the battery management system main controllers, wherein each battery pack is provided with one battery management system auxiliary controller.

According to a fifth aspect of the present application, there is also provided a vehicle including: any one of the multi-battery pack parallel systems described above.

According to the power control method and the device thereof, the multi-battery-pack parallel system and the vehicle, the voltage, the temperature and the state of charge value of each battery pack are received in real time; determining the maximum discharging current or the maximum charging current of the multi-battery parallel system according to the temperature and the state of charge value of each battery pack; and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system, so that the plurality of parallel battery packs have larger charge and discharge power on the premise of meeting safety and reliability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.

FIG. 1 is a flow chart of a power control method of a multi-battery parallel system according to an embodiment of the invention;

FIG. 2 is a topology of a multi-battery parallel system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a controller connection of a plurality of multi-battery parallel systems on a rail train according to an embodiment of the present invention;

FIG. 4 is a high voltage power-on flow chart of a multi-battery parallel system according to an embodiment of the invention;

FIG. 5 is a flow chart illustrating power control during discharging of a multi-battery parallel system according to an embodiment of the present invention;

FIG. 6 is a charge flow diagram of a multi-battery parallel system according to an embodiment of the present invention;

FIG. 7 is a flow chart illustrating power control during charging of a multi-battery parallel system according to an embodiment of the present invention;

fig. 8 is a schematic block diagram of a power control device of a multi-battery parallel system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. It should be apparent that the described embodiments are only some embodiments of the present invention and not all embodiments of the present invention, and it should be understood that the present invention is not limited by the example embodiments described herein. Based on the embodiments of the invention described in the present application, all other embodiments that a person skilled in the art would have without inventive effort shall fall within the scope of the invention.

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without one or more of these details. In other instances, well-known features have not been described in detail in order to avoid obscuring the invention.

It should be understood that the present invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present invention, detailed structures will be presented in the following description in order to illustrate the technical solutions presented by the present invention. Alternative embodiments of the invention are described in detail below, however, the invention may have other implementations in addition to these detailed descriptions.

Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

Firstly, an application scenario of the power control method of the multi-battery parallel system in the present application needs to be introduced, and the power control method of the multi-battery parallel system is applied to the multi-battery parallel system and is used for controlling the charge and discharge power of the multi-battery parallel system, wherein the multi-battery parallel system includes a plurality of parallel battery packs.

Referring to fig. 1, an embodiment of the present application provides a power control method of a multi-battery parallel system, including:

Step one: receiving a voltage, a temperature and a state of charge value for each battery pack;

step two: determining the maximum discharge current or the maximum charge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery pack;

Step three: and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system.

In the scheme, the voltage, the temperature and the state of charge value of each battery pack are received in real time; determining the maximum discharging current or the maximum charging current of the multi-battery parallel system according to the temperature and the state of charge value of each battery pack; and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system, so that the plurality of parallel battery packs have larger charge and discharge power on the premise of meeting safety and reliability. The steps are described in detail below with reference to the accompanying drawings.

First, referring to fig. 1, voltage, temperature, and state of charge values of each battery pack are received. A battery management system auxiliary controller may be provided in each battery pack, and the battery management system auxiliary controller may be configured to obtain the voltage, temperature, and state of charge values of the corresponding battery pack, and after the obtaining, may be transmitted to a battery management system main controller of the multi-battery pack parallel system, thereby obtaining the voltage, temperature, and state of charge values of each battery pack.

In particular, various ways may be employed. Reference is made to the topology of a multi-stack parallel system shown in fig. 2 and the controller connection schematic of the multi-stack shown in fig. 3. Each battery pack of the multi-battery pack parallel system is provided with a battery management system auxiliary controller, the multi-battery pack parallel system is also provided with a battery management system main controller, and the battery management system main controller is used for interacting with all battery management system auxiliary controllers of the same multi-battery pack parallel system to acquire state information of each battery pack.

Reference to fig. 3 illustrates an application scenario of a multi-battery parallel system, which is applied to a rail train with n vehicles, wherein each vehicle is provided with a multi-battery parallel system, and each vehicle power battery system is relatively independent. Each multi-battery-pack parallel system is provided with n battery packs, each battery pack is provided with a battery management system auxiliary controller (respectively called auxiliary controllers 1-n for short), and a battery management system main controller in each multi-battery-pack parallel system is in communication connection with a whole car control system of a rail train so as to interact with the whole car control system and acquire information such as power requirements of the rail train in real time. That is, each vehicle includes a plurality of parallel battery packs, battery management systems (battery management system auxiliary controllers, battery management system main controllers), electric appliance assemblies, charger assemblies and the like. The whole vehicle control system can be communicated with a main controller of a battery management system of each vehicle in a unified way, and the main controller is communicated with an auxiliary controller of the battery management system.

The auxiliary controller of the battery management system and the main controller of the battery management system can control the battery pack and the whole rail train to carry out high-voltage charging and charging according to a specified flow, and control the discharging power of the battery pack in a high-voltage charging state and the charging power of the battery pack in a charging state. The battery management system can collect high-voltage power-on signals and charging signals sent by the whole railway train, and can jointly control the switching state of each battery pack through the main control and the auxiliary control of the battery management system, and the control state of each battery pack is real-time and dynamic.

Next, a maximum discharge current or a maximum charge current of the multi-battery parallel system is determined according to the temperature and state of charge value of each battery. In determining whether the maximum discharge current or the maximum charge current of the multi-battery parallel system is the same, it is related to the current state of the multi-battery parallel system. If the current multi-battery parallel system is in a discharge state, determining the maximum discharge current of the multi-battery parallel system; if the current multi-battery parallel system is in a charged state, a maximum charging current of the multi-battery parallel system is determined.

Next, referring to fig. 1, in determining the maximum discharge current or the maximum charge current of the multi-battery parallel system, the maximum discharge power or the maximum charge power of the multi-battery parallel system is also determined according to the voltage of each battery and the maximum discharge current or the maximum charge current of the multi-battery parallel system. Specifically, the current maximum discharge power of the multi-battery parallel system can be determined according to the maximum discharge current of the multi-battery parallel system; according to the maximum charging current of the multi-battery parallel system, the current maximum charging power of the multi-battery parallel system is determined, so that the plurality of parallel battery packs have larger charging and discharging power on the premise of meeting safety and reliability.

Illustratively, when the multi-battery parallel system is in a discharge state, the power control method may further include: determining the highest voltage of the multiple battery packs according to the voltage of each battery pack; and screening out all battery packs with the difference value with the highest voltage within a preset difference value, and taking the battery packs as the current discharging battery packs of the multi-battery-pack parallel system. That is, when the multi-battery parallel system discharges to the outside, not each battery is discharged to the outside, but one or more battery is selected from the plurality of battery as the current discharging battery. The voltage of the battery packs in the discharge battery packs is the highest voltage in all the battery packs at present, or the voltage with the difference value from the highest voltage being smaller than the preset difference value, namely the voltage of each battery pack in the discharge battery packs is in a good state, so that the battery packs in the discharge battery packs are not mutually charged or discharged in the external discharge process, and the safety and reliability of discharge are improved. The size of the preset difference value can be reasonably determined based on factors such as the type of the battery pack, the number of the battery cells and the like.

For example, when determining the maximum discharge current of the multi-battery parallel system according to the temperature and state of charge value of each battery pack, the maximum discharge current of the multi-battery parallel system may be determined according to the temperature and state of charge value of each battery pack in the discharged battery packs. Since only the battery packs in the discharging battery pack participate in the external discharging of the multi-battery pack parallel system at the current moment and other battery packs do not participate in the external discharging, the maximum discharging current of the multi-battery pack parallel system can be determined according to the temperature and the state of charge value of each battery pack in the discharging battery pack without considering the influence of the battery packs which do not discharge to the discharging current.

For example, when determining the maximum discharge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery in the discharge battery, the highest temperature and the lowest temperature of all battery in the discharge battery can be selected; then, calculating the average value of the charge state values of all the battery packs in the discharge battery packs; then, the maximum discharge current of the multi-battery parallel system is determined according to the average value of the highest temperature, the lowest temperature and the state of charge value. The maximum discharge current of the multi-battery parallel system is reasonably determined by considering the temperature distribution condition of each battery pack in the discharge battery packs and combining the current state of charge value condition of each battery pack in the current discharge battery pack, so that more accurate maximum discharge current can be determined.

For example, when determining the maximum discharge current of the multi-battery parallel system based on the average of the maximum temperature, the minimum temperature, and the state of charge value, in some embodiments, the first discharge current corresponding to the average of the maximum temperature and the state of charge value may be found based on a state of charge-temperature-allowable discharge current discharge ammeter; based on a discharge ammeter of the charge state-temperature-allowable discharge current, searching a second discharge current corresponding to the average value of the lowest temperature and the charge state value; and then taking the minimum value of the first discharge current and the second discharge current as the maximum discharge current of the multi-battery parallel system. The first discharge current corresponding to the highest temperature and the second discharge current corresponding to the lowest temperature are obtained through a table look-up mode, and then the minimum value of the first discharge current and the second discharge current is selected to be used as the maximum discharge current of the whole multi-battery parallel system, so that each battery pack in the discharge battery packs can output the determined maximum discharge current when discharging outwards, and the maximum discharge current of the whole multi-battery parallel system can be determined more accurately.

Table 1 below shows an exemplary state of charge-temperature-discharge ammeter that allows discharge current. As shown in table 1, the first row represents the current state of charge value of the battery pack, and in the embodiment of the present application, the average of the state of charge values of all the battery packs in the battery packs (discharged battery packs) that are put into use, that is, the average of the state of charge values soc=soc ₁+···+SOC_n/n, when n battery packs are included in the discharged battery packs. The first column indicates the temperature of the battery pack, and in the present example, the highest temperature and lowest temperature of all the battery packs in the discharged battery pack are selected.

TABLE 1 State of Charge-temperature-discharge ammeter allowing discharge Current

T/℃

＜5％

5％

10％

15％

20％

30％

≥40％

T_A

I_A

I_B

I_C

I_D

I_E

T_B

I_A

I_D

I_E

T_C

I_A

I_D

I_E

I_F

T_D

I_A

I_E

I_F

I_G

T_E

I_B

I_E

I_I

I_H

T_F

I_B

I_E

I_F

I_K

T_G

I_B

I_E

I_G

I_L

I_M

T_H

I_B

I_E

I_K

I_N

T_I

I_C

I_E

I_K

I_N

I_P

T_J

I_C

I_F

I_L

I_O

I_Q

T_K

I_D

I_F

I_M

I_P

I_R

T_L

I_D

I_F

I_M

I_P

I_R

T_M

I_D

I_F

I_M

I_P

I_R

T_N

I_D

I_F

I_M

I_P

I_R

T_O

I_D

I_F

I_M

I_P

I_R

T_P

I_D

I_F

I_M

I_P

I_R

T_Q

I_D

I_F

I_K

I_M

I_P

After the average value, the highest temperature and the lowest temperature of the charge state values of all the discharged battery packs are determined in the table 1 according to ,T_A<T_B<T_C<T_D<T_E<T_F<T_G<T_H<T_I<T_J<T_K<T_L<T_M<T_N<T_O<T_P<T_Q,I_A<I_B<I_C<I_D<I_E<I_F<I_G<I_K<I_L<I_M<I_N<I_O<I_P<I_Q<I_R., the first discharge current and the second discharge current can be obtained through table 1, and the minimum value of the first discharge current and the second discharge current is selected as the maximum discharge current I _max of the multi-battery-pack parallel system at this time.

The power-up and external discharge processes of a multi-battery parallel system are exemplarily shown in the following with reference to fig. 4 and 5. As shown in fig. 4, after the entire rail train is powered on successfully, it is determined whether the self-checking states of the main control and auxiliary controllers of the battery management system are normal. If the self-checking of the main control (the main control and the auxiliary controller of the battery management system) is normal, the main control judges whether the auxiliary control of the self-checking is normal or not. Firstly, judging the battery pack with the highest current voltage, then finding the battery packs with the voltage difference value within Vdiff (preset difference value), taking the battery packs as discharge battery packs, sending input instructions to auxiliary control of the battery packs, and then controlling the closing of contactors in the battery packs by the auxiliary control. When the main control receives a command of requesting high-voltage power-on sent by the whole vehicle, the main control controls each contactor to carry out high-voltage power-on according to a set high-voltage current range. After the high-voltage power-on is successful, the main control obtains the maximum discharge current of the multi-battery parallel system at the moment through checking the voltage of each battery pack, the temperature of each battery pack and the state of charge value fed back by the auxiliary control and through checking the state of charge-temperature-discharge ammeter allowing the discharge current, and further obtains the maximum discharge power.

As shown in fig. 4, when the high voltage is successfully powered up, the main controller collects the highest temperature, the lowest temperature and the state of charge value of each battery pack in the discharged battery packs put into use. And the average value of the state of charge values of the respective battery packs in the discharged battery packs is calculated. Then, using the average value of the highest temperature and the state of charge value, the average value of the lowest temperature and the state of charge value, respectively, the first discharge current and the second discharge current can be obtained by table look-up 1. And comparing the two current values, and taking the smaller one of the two current values, wherein the smaller one is the maximum discharge current I _max of the external discharge of the current multi-battery parallel system. Since the battery packs are connected in parallel in the circuit, when the battery packs are put in, the voltages U of the battery packs are equal, and the maximum discharge power W _max＝U×I_max of the multi-battery pack parallel system is at this time. If the vehicle is not powered down at high voltage or the lowest voltage of each battery pack does not reach the threshold V _min, the main control needs to continuously acquire and calculate data to obtain the real-time maximum discharge power W _max. Wherein, vehicle does not high voltage return electricity refers to: the multi-battery parallel system also does not stop discharging during high-voltage power-up of the vehicle. Vmin refers to the minimum voltage at which the multi-cell parallel system operates, and if the minimum voltage is lower than the minimum voltage value, the multi-cell parallel system is overdischarged, and the multi-cell parallel system is stopped from discharging outwards before overdischarging. As long as the multi-battery parallel system is still normally discharging and has no overdischarge phenomenon, the discharging power control mode shown in the embodiment of the application is adopted for power control.

It should be understood that the foregoing is merely illustrative of the manner in which the power of the multi-battery parallel system is controlled when discharged to the outside, and other control methods may be employed.

In other embodiments, when the multi-battery parallel system is in a charged state, the maximum charging current of the multi-battery parallel system is determined according to the temperature and the state of charge value of each battery, the highest temperature and the lowest temperature of all the battery packs which are not fully charged in the multi-battery parallel system can be screened; then, calculating the average value of the charge state values of all the battery packs which are not fully charged; then, the maximum charging current of the multi-battery parallel system is determined according to the average value of the highest temperature, the lowest temperature and the state of charge value. When the charging current of the multi-battery parallel system is determined, only the temperature condition and the state of charge value condition of all the battery packs which are not fully charged are considered, and the condition of the battery packs which are fully charged is not considered, so that the determined charging current is more accurate.

In determining the maximum charging current of the multi-battery parallel system based on the average of the highest temperature, the lowest temperature, and the state of charge value, the following manner may be exemplarily employed. The first charging current corresponding to the average value of the highest temperature and the state of charge value can be searched based on a state of charge-temperature-charging current meter allowing the charging current; searching a second charging current corresponding to the average value of the lowest temperature and the state of charge value based on a charging ammeter of the state of charge-temperature-allowable charging current; and then, taking the minimum value of the first charging current and the second charging current as the maximum charging current of the multi-battery-pack parallel system. The first charging current corresponding to the highest temperature and the second charging current corresponding to the lowest temperature are obtained through a table look-up mode, and then the minimum value of the first charging current and the second charging current is selected to be used as the current maximum charging current of the whole multi-battery parallel system, so that when all the battery packs which are not fully charged are charged, an external charger can input the determined maximum charging current to each battery pack which is not fully charged, and the maximum charging current of the whole multi-battery parallel system is more accurately determined.

Table 2 below shows an exemplary state of charge-temperature-discharge ammeter that allows charge current. As shown in table 2, the first row represents the current state of charge value of the battery pack, and in the embodiment of the present application, the average of the state of charge values of all the battery packs in the battery packs (the underfilled battery packs) that are put into use, that is, the average of the state of charge values soc=soc ₁+···+SOC_n/n, when n battery packs are included in the underfilled battery packs. The first column indicates the temperature of the battery pack, and in the present example, the highest temperature and lowest temperature of all the battery packs that are not full are selected.

TABLE 2 State of charge-temperature-discharge ammeter allowing charging Current

T/℃

0％

10％

20％

30％

40％

50％

60％

70％

80％

90％

≥95％

T_A

I_B

I_A

T_B

I_C

I_B

T_C

I_D

I_C

T_D

I_F

I_E

I_D

T_E

I_H

I_G

I_D

T_F

I_K

I_H

I_G

I_F

I_D

T_G

I_M

I_K

I_H

I_G

I_D

T_H

I_N

I_M

I_K

I_H

I_D

T_I

I_O

I_M

I_L

I_J

I_D

T_J

I_O

I_M

I_L

I_J

I_D

T_K

I_O

I_M

I_L

I_J

I_D

T_L

I_O

I_M

I_L

I_J

I_D

T_M

I_O

I_M

I_L

I_J

I_D

T_N

I_M

I_L

I_J

I_D

T_O

I_H

I_D

T_P

I_G

I_E

I_D

T_Q

I_A

After the average value, the highest temperature and the lowest temperature of the charge state values of all the underfilled battery packs are determined in the table 2 by ,T_A<T_B<T_C<T_D<T_E<T_F<T_G<T_H<T_I<T_J<T_K<T_L<T_M<T_N<T_O<T_P<T_Q,I_A<I_B<I_C<I_D<I_E<I_F<I_G<I_K<I_L<I_M<I_N<I_O., the first charging current and the second charging current can be obtained by looking up the table 2, and the minimum value of the first charging current and the second charging current is selected as the maximum charging current I _max of the multi-battery-pack parallel system at this time.

Illustratively, when the multi-battery parallel system is in a charged state, the power control method may further include: judging whether each battery pack is full or not according to the voltage and the state of charge value of each battery pack; and when the battery packs are full, after the maximum charging current value of the multi-battery pack parallel system is controlled to be not more than a preset threshold value, disconnecting the full battery packs from an external charger. And judging whether each battery pack is full in real time, when the battery packs are full, controlling the maximum charging current of the multi-battery pack parallel system to be reduced below a preset threshold value, and then disconnecting the electric connection between the full battery packs and an external charger to prevent the contactor from sintering.

A charging flow at the time of application is described below with reference to fig. 6 and 7. As shown in fig. 6, the battery management system determines whether a charging request sent by the whole vehicle control system is received. If the self-checking is received, the main control and the auxiliary control of the battery management system are needed to carry out self-checking respectively, and if the main control self-checking is normal, the main control controls the input of the auxiliary control with normal self-checking. The battery management system performs handshake identification and parameter matching with a charging cabinet in the direct-current charger assembly. The master control obtains the maximum charging current of the multi-battery parallel system at the moment through the voltage, the battery temperature and the state of charge value of each battery pack fed back by the auxiliary control and the table lookup 2, so as to obtain the maximum charging power.

As shown in fig. 6, when the system enters a state of charge, the main controller collects the highest temperature, lowest temperature, and state of charge values of each battery pack (underfilled battery pack) that is put into use. Calculating the average value of the state of charge values of all the battery packs which are not fully charged, and using the average value of the highest temperature and the state of charge value, the average value of the lowest temperature and the state of charge value respectively, table 1 can obtain a first charging current and a second charging current. And comparing the two current values, and taking the smaller one of the two current values, wherein the smaller one is the maximum charging current I _max of the current multi-battery parallel system. The output voltage of the charging cabinet is U. Because constant current charging is adopted, the output voltage U of the charging cabinet can be increased along with the voltage increase of the battery pack in the charging process. At this time, the maximum charging power W _max＝U×I_max. Because the embodiment of the application carries out parallel control of a plurality of battery packs, and each battery pack has a difference, the current state of charge value of each battery pack which is not fully charged and the voltage of each battery pack can be detected in real time and used for judging whether the battery pack is fully charged or not. If the battery pack is full, the current maximum current value of the current multi-battery pack parallel system can be controlled to be I _max =5a (preset threshold value), so that the contactor load is smaller and the contactor is prevented from sintering when the battery pack which is completely charged is disconnected from the external charger assembly. Then, the main control controls the battery pack to be disconnected. The main control continues to collect the information of the battery pack still being charged, and recalculates the average value of the charge state values of the battery pack which is not fully charged and the maximum charging current I _max. The maximum charging power W _max＝U×I_max at this time is recalculated. And controlling all the accessed battery packs to be sequentially full through the flow.

In the various embodiments shown above, the voltage, temperature, and state of charge values of each battery pack are received in real time; determining the maximum discharging current or the maximum charging current of the multi-battery parallel system according to the temperature and the state of charge value of each battery pack; and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system, so that the plurality of parallel battery packs have larger charge and discharge power on the premise of meeting safety and reliability. The charging and discharging power of the battery packs is dynamically controlled in real time by collecting the input state, voltage and temperature of each battery pack in real time and inquiring the charging state-temperature-allowable charging and discharging current discharging ammeter of the battery packs.

In addition, the embodiment of the application also provides a power control device of the multi-battery parallel system, which comprises: the power control system comprises a storage medium and a processor, wherein the storage medium is stored with a computer program which is run by the processor and enables the processor to execute any power control method of the multi-battery parallel system when the computer program is run by the processor. When the power control device of the multi-battery pack parallel system is applied to the multi-battery pack parallel system, the power control device of the multi-battery pack parallel system may be provided in a battery management system main controller of the multi-battery pack parallel system.

Fig. 8 shows a schematic block diagram of a power control apparatus 100 of a multi-battery parallel system according to an embodiment of the present application. As shown in fig. 8, the power control apparatus 100 of the multi-battery parallel system according to the embodiment of the present application may include a storage medium 110 and a processor 120, the storage medium 110 storing a computer program executed by the processor 120, which when executed by the processor 120, causes the processor 120 to perform the foregoing power control method of the multi-battery parallel system according to the embodiment of the present application. Those skilled in the art can understand the specific operation of the power control device 100 deployment device of the multi-battery parallel system according to the embodiment of the present application in combination with the foregoing, and for brevity, the description is omitted here.

The storage medium 110 may include, for example, a memory card of a smart phone, a memory component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the foregoing storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

In addition, the embodiment of the application also provides a battery management system main controller, which comprises the power control device of any multi-battery-pack parallel system.

Furthermore, the embodiment of the application also provides a multi-battery-pack parallel system, which comprises: the battery management system comprises a plurality of battery packs, a plurality of battery management system auxiliary controllers and any one of the battery management system main controllers which are connected in parallel, wherein each battery pack is provided with one battery management system auxiliary controller.

In addition, the embodiment of the application also provides a vehicle, which comprises: any one of the multi-battery pack parallel systems described above. The vehicle may also include a vehicle body that may include frame, wheels, gearbox, steering wheel, etc. structures. The vehicle can be an electric vehicle, in particular a trolley bus, an electric automobile and the like, and the battery pack parallel system is used as a power supply system of the trolley bus or the electric automobile. Referring to fig. 2, the vehicle may further include an electric appliance assembly and a charger assembly, wherein the electric appliance assembly is used for using the battery pack parallel system to discharge electricity, i.e. is used for consuming the battery pack electric quantity in a high-voltage power-on state; the charger assembly allows external charging of the multi-battery parallel system therethrough. According to the embodiment of the application, the power control of the whole vehicle in the discharging of the battery pack in the high-voltage power-on state and the charging of the battery pack in the charging state can be realized through the linkage of the functions of a plurality of products such as the battery packs in the multi-battery pack parallel system, the battery management system auxiliary controller, the battery management system main controller, the electric appliance assembly, the charger assembly and the like. In the embodiment of the application, the auxiliary controller of the battery management system transmits the real-time state of a single battery pack, the main controller of the battery management system identifies the temperature, the voltage and the state of charge value of the battery pack, and the maximum charge and discharge current allowed by the multi-battery pack parallel system at the moment is obtained through a table lookup method, so that the charge and discharge power of the multi-battery pack parallel system is obtained.

The present invention has been illustrated by the above-described embodiments, but it should be understood that the above-described embodiments are for purposes of illustration and description only and are not intended to limit the invention to the embodiments described. In addition, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications are possible in light of the teachings of the invention, which variations and modifications are within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A power control method for a multi-battery parallel system, comprising:

receiving a voltage, a temperature and a state of charge value of each battery pack;

Determining a maximum discharge current or a maximum charge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery;

and determining the maximum discharge power or the maximum charge power of the multi-battery parallel system according to the voltage of each battery pack and the maximum discharge current or the maximum charge current of the multi-battery parallel system.

2. The power control method of claim 1, further comprising, when the multi-battery parallel system is in a discharge state:

determining a highest voltage of the multi-battery pack according to the voltage of each battery pack;

And screening out all battery packs with the difference value within a preset difference value from the highest voltage to serve as the current discharging battery packs of the multi-battery pack parallel system.

3. The power control method of claim 2, wherein said determining a maximum discharge current of said multi-stack parallel system based on said temperature and said state of charge value of each of said stacks comprises:

And determining the maximum discharge current of the multi-battery parallel system according to the temperature and the state of charge value of each battery pack in the discharge battery packs.

4. The power control method of claim 3, wherein said determining a maximum discharge current of said multi-stack parallel system based on said temperature and said state of charge value of each of said discharged stacks comprises:

screening out the highest temperature and the lowest temperature of all battery packs in the discharge battery packs;

Calculating the average value of the charge state values of all the battery packs in the discharge battery packs;

and determining the maximum discharge current of the multi-battery parallel system according to the average value of the highest temperature, the lowest temperature and the state of charge value.

5. The power control method of claim 4, wherein said determining a maximum discharge current of said multi-battery parallel system based on an average of said maximum temperature, said minimum temperature, and said state of charge value comprises:

Searching a first discharge current corresponding to the highest temperature and the average value of the charge state values based on a discharge ammeter of the charge state-temperature-allowable discharge current;

Searching a second discharge current corresponding to the lowest temperature and the average value of the charge state values based on the discharge ammeter of the charge state-temperature-allowable discharge current;

And taking the minimum value of the first discharging current and the second discharging current as the maximum discharging current of the multi-battery-pack parallel system.

6. The power control method of claim 1, wherein determining a maximum charge current for the multi-battery parallel system based on the temperature and the state of charge value for each of the battery packs while the multi-battery parallel system is in a charged state comprises:

screening out the highest temperature and the lowest temperature of all the battery packs which are not fully charged in the multi-battery pack parallel system;

Calculating an average value of the state of charge values of all the battery packs which are not fully charged;

And determining the maximum charging current of the multi-battery parallel system according to the average value of the highest temperature, the lowest temperature and the state of charge value.

7. The power control method of claim 6, wherein said determining a maximum charge current of said multi-battery parallel system based on an average of said maximum temperature, said minimum temperature, and said state of charge value comprises:

Searching a first charging current corresponding to the highest temperature and the average value of the charge state values based on a charge state-temperature-charging current table allowing the charging current;

searching a second charging current corresponding to the lowest temperature and the average value of the charge state values based on the charge state-temperature-charging current table allowing the charging current;

And taking the minimum value of the first charging current and the second charging current as the maximum charging current of the multi-battery-pack parallel system.

8. The power control method of claim 6, further comprising, when the multi-battery parallel system is in a charged state:

Judging whether each battery pack is full or not according to the voltage and the state of charge value of each battery pack;

And when the battery pack is full, after the maximum charging current value of the multi-battery pack parallel system is controlled to be not more than a preset threshold value, disconnecting the full battery pack from an external charger.

9. A power control device for a multi-battery parallel system, comprising:

A storage medium and a processor, the storage medium having stored thereon a computer program to be run by the processor, which computer program, when run by the processor, causes the processor to perform the power control method of the multi-battery parallel system as claimed in any one of claims 1 to 8.

10. A battery management system main controller, comprising: the power control device of the multi-battery parallel system of claim 9.

11. A multi-battery parallel system, comprising:

a plurality of battery packs connected in parallel;

A plurality of auxiliary controllers of the battery management system, wherein each battery pack is provided with one auxiliary controller of the battery management system;

the battery management system host controller of claim 10.

12. A vehicle, characterized by comprising: the multi-battery parallel system of claim 11.