CN104409789A - Method for charging battery pack with temperature protection function in battery pack electric quantity unbalanced state - Google Patents

Method for charging battery pack with temperature protection function in battery pack electric quantity unbalanced state Download PDF

Info

Publication number
CN104409789A
CN104409789A CN201410680904.3A CN201410680904A CN104409789A CN 104409789 A CN104409789 A CN 104409789A CN 201410680904 A CN201410680904 A CN 201410680904A CN 104409789 A CN104409789 A CN 104409789A
Authority
CN
China
Prior art keywords
temperature
battery
charging
battery pack
charge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201410680904.3A
Other languages
Chinese (zh)
Other versions
CN104409789B (en
Inventor
朱春波
孙金磊
宋凯
杨鹏
胡宸
魏国
逯仁贵
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Harbin Institute of Technology
Original Assignee
Harbin Institute of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Harbin Institute of Technology filed Critical Harbin Institute of Technology
Priority to CN201410680904.3A priority Critical patent/CN104409789B/en
Publication of CN104409789A publication Critical patent/CN104409789A/en
Application granted granted Critical
Publication of CN104409789B publication Critical patent/CN104409789B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H01M10/443—Methods for charging or discharging in response to temperature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention provides a method for charging a battery pack with a temperature protection function in a battery pack electric quantity unbalanced state, relates to a charging method in the battery pack electric quantity unbalanced state, and aims to solve the over-temperature and unbalanced temperature problems during charging of a battery pack because inconformity of single batteries causes unbalancing of the residual electric quantities of the single batteries. The method comprises the following steps: analyzing heat balance equations for the single batteries with the highest and lowest electric quantities respectively in the battery pack to confirm the highest temperature of the single batteries at the end of the charging process; limiting charging current according to both the highest working temperature provided by the manual of the single batteries and the allowable range of the largest temperature difference in the battery pack, so that the battery pack can work within the allowable temperature range. The method is suitable for the application fields of series battery packs, such as electrically-propelled vehicles and large-scale energy storage systems.

Description

Charging method under a kind of battery electric quantity imbalance with temperature protection function
Technical field
The present invention relates to the charging method under a kind of battery electric quantity imbalance, relate to Li-ion batteries piles discharge and recharge technical field.
Background technology
The battery pack that desirable cell is formed can release electricity under the prerequisite not considering the inconsistent factors such as internal resistance, temperature, open circuit voltage, coulombic efficiency, capacity and monomer should be consistent, but due to the objective reality of battery cell inconsistency, cascaded lithium ion batteries group there will be the electricity difference of monomer in battery pack after repeatedly cycle charge-discharge, the inequality of heat-dissipating can be brought in charging process to cause battery temperature inconsistent if ignore this species diversity, show causing cell degradation degree varies and battery excess temperature even bring danger.So object of the present invention is exactly to consider consider the battery balanced temperature impact brought under battery pack unbalanced prerequisite, propose a kind ofly can ensure that in battery charging process, temperature is in the charging method of allowed band.
Summary of the invention
The object of this invention is to provide the charging method under a kind of battery electric quantity imbalance with temperature protection function, to solve, dump energy between the inconsistent batteries monomer caused of battery cell is unbalanced can cause the unequal problem of mild temperature when batteries charging.
The present invention solves the problems of the technologies described above the technical scheme taked to be:
Have the charging method under the battery electric quantity imbalance of temperature protection function, the method comprises the steps:
Step one: choose maximum SOC according to monomer remaining capacity SOC each in the battery pack obtained maxwith minimum SOC min, when charging to this battery pack, the charging interval can be expressed as:
t CHARGE = ( 1 - SOC max ) · C N I CHARGE
Wherein C nfor battery capacity, t cHARGEfor charging required time, I cHARGEfor charger constant current charge electric current;
Step 2: obtain the most high monomer of SOC and the minimum monomer of SOC t in charging process according to battery equation of heat balance and heat-dissipating, heat radiation equation cHARGEin time, I cHARGEtemperature under electric current at the end of charging represents with equation of heat balance:
cC p dT dt = H t in - H t out
Wherein m is monomer mass, C pbe battery thermal capacity, T is that (t is here the some moment represented in charging process to battery t, with charging total time t cHARGEan implication) temperature, represent battery heat-dissipating, represent battery heat radiation;
The following the Representation Equation of battery heat-dissipating:
H t in = η t I CHARGE - I CHARGE TΔS nF
η in heat-dissipating equation tfor overpotential, i.e. the difference of t battery terminal voltage and open circuit voltage, △ S is the Entropy Changes in chemical reaction, and n is the electron amount participating in chemical reaction, and F is Faraday constant; Use equation show that Entropy Changes and the derivative of open circuit voltage to temperature exist certain relation;
The following the Representation Equation of battery heat transmission:
H t out = hA ( T - T a )
In heat radiation equation, h represents thermal transmission coefficient, and A is surface area, T afor ambient temperature;
Obtain thermal characteristics basic parameter: battery thermal capacity, conductive coefficient, then can solve in electric current I according to equation of heat balance, heat-dissipating and heat radiation three equations cHARGEany monomer temperature at any time in charging process:
T=f (I cHARGE, t, SOC) and t represents some moment,
Step 3, according in battery cell maximum temperature and battery pack between monomer maximum temperature difference provide restrictive condition:
In battery pack, any monomer any time maximum temperature is no more than the maximum temperature that handbook provides, T max<T def,
Temperature difference in battery pack arbitrarily between monomer is less than 5 degree, △ T max<5 DEG C;
At the end of step 4, charging, namely the maximum electricity of t and the temperature of minimum amount of power battery cell should meet T max<T def, meanwhile, maximum electricity monomer and the maximum temperature difference of minimum amount of power monomer within the 0-t time period should meet △ T max<5 DEG C, obtains I from these two restrictive conditions cHARGEi.e. maximum charging current.
The beneficial effect of the method:
The invention provides the charging strategy in the unbalanced situation of battery electric quantity considering temperature.Ensure that in battery pack, monomer maximum temperature is lower than the permission upper limit by adjustment charging current, ensure that between monomer, temperature contrast is lower than 5 degree simultaneously.For having the unbalanced battery pack of to a certain degree electricity, the present invention is by limiting in charging process maximum temperature difference between monomer maximum temperature and monomer, obtain the maximum charging current of this battery pack in this, as restrictive condition to ensure that in batteries charging process, temperature is all in allowed band, ensure the safe and reliable work of battery pack.
The present invention is directed to and easy to chargely when electricity is unbalanced between batteries monomer occur the problem that individual monomers crosses temperature inequality between gentle monomer, solve when not possessing equilibrium condition, battery electric quantity is unbalanced and when needing charging, avoids occurring in charging process excess temperature or temperature uneven phenomenon and causes cell degradation degree different.Thus ensure that battery pack still can safe charging under imbalance, and the phenomenon of mild temperature inequality can not be caused.Concrete advantage of the present invention is as follows: one, the invention provides battery electric quantity unbalanced time still can ensure the strategy of safe charging, this strategy can effectively predict battery heat-dissipating and variations in temperature, simple and practical, has general applicability.Two, charging strategy when battery electric quantity proposed by the invention is unbalanced, can ensure monomer only while temperature, ensure that maximum temperature difference is lower than 5 degree in battery pack.Avoid due to temperature inequality cause aging inconsistent.Three, charging current of the present invention obtains according to battery temperature, effectively can prevent the appearance of thermal runaway in charging process, play a protective role.
This method determines battery charging maximum temperature in latter stage by analysis that is the highest to electricity in battery pack and minimum monomer equation of heat balance, limit charging current according to maximum temperature difference allowed band in handbook of batteries maximum operating temperature and battery pack, ensure that battery pack is operated within the scope of allowable temperature.This method is applicable to the series battery such as electric automobile, large-scale energy storage system application.
Accompanying drawing explanation
Fig. 1 is the charging method flow chart under a kind of battery electric quantity imbalance with temperature protection function; Fig. 2 is that monomer OCV is with SOC change curve; Fig. 3 is that monomer open circuit voltage varies with temperature curve (abscissa representing time, ordinate represents voltage); The temperature profile of the most high monomer of temperature at the end of Fig. 4 is charging, Fig. 5 is the maximum operation temperature curve chart in charging process.
Embodiment
Embodiment one, composition graphs 1 ~ 3 illustrate present embodiment, and the charging method had under the battery electric quantity imbalance of temperature protection function described in present embodiment comprises the steps:
Step one: choose maximum SOC according to monomer remaining capacity SOC each in the battery pack obtained maxwith minimum SOC min, when charging to this battery pack, the charging interval can be expressed as:
t CHARGE = ( 1 - SOC max ) &CenterDot; C N I CHARGE
Wherein C nfor battery capacity, t cHARGEfor charging required time, I cHARGEfor charger constant current charge electric current;
Step 2: obtain the most high monomer of SOC and the minimum monomer of SOC t in charging process according to battery equation of heat balance and heat-dissipating, heat radiation equation cHARGEin time, I cHARGEtemperature under electric current at the end of charging represents with equation of heat balance:
cC p dT dt = H t in - H t out
Wherein m is monomer mass, C pbe battery thermal capacity, T is that (t is here the some moment represented in charging process to battery t, with charging total time t cHARGEbe not an implication, in the charging interval, place changes) temperature, represent battery heat-dissipating, represent battery heat radiation;
The following the Representation Equation of battery heat-dissipating:
H t in = &eta; t I CHARGE - I CHARGE T&Delta;S nF
η in heat-dissipating equation tfor overpotential, i.e. the difference of t battery terminal voltage and open circuit voltage, △ S is the Entropy Changes in chemical reaction, and n is the electron amount participating in chemical reaction, and F is Faraday constant; Use equation show that Entropy Changes and the derivative of open circuit voltage to temperature exist certain relation;
As shown in Figure 2, under each SOC, OCV varies with temperature curve and can obtain according to Fig. 3 for battery terminal voltage and OCV curve, and simulates corresponding relation expression formula;
Fig. 2 and Fig. 3 is the step obtaining call parameter in order to using said method, as utilized cell voltage difference to calculate battery heat-dissipating, and utilizes open circuit voltage variations to obtain Entropy Changes heat-dissipating
The following the Representation Equation of battery heat transmission:
H t out = hA ( T - T a )
In heat radiation equation, h represents thermal transmission coefficient, and A is surface area, T afor ambient temperature;
Obtain thermal characteristics basic parameter: battery thermal capacity, conductive coefficient, then can solve in electric current I according to equation of heat balance, heat-dissipating and heat radiation three equations cHARGEany monomer temperature at any time in charging process:
T=f (I cHARGE, t, SOC) and t represents some moment,
Step 3, according in battery cell maximum temperature and battery pack between monomer maximum temperature difference provide restrictive condition:
In battery pack, any monomer any time maximum temperature is no more than the maximum temperature that handbook provides, T max<T def,
Temperature difference in battery pack arbitrarily between monomer is less than 5 degree, △ T max<5 DEG C;
At the end of step 4, charging, namely the maximum electricity of t and the temperature of minimum amount of power battery cell should meet T max<T def, meanwhile, maximum electricity monomer and the maximum temperature difference of minimum amount of power monomer within the 0-t time period should meet △ T max<5 DEG C, obtains I from these two restrictive conditions cHARGEi.e. maximum charging current.
In step 4, by described two restrictive condition T max<T defwith △ T max<5 DEG C obtains I cHARGEnamely the process of maximum charging current is:
By formula T=f (I cHARGE, t, SOC), T maxuse I charge, t and SOC represent, the moment, t and SOC was known, T maxuse I cHARGErepresent, if so define T maxscope, also just can limit I cHARGEscope; For △ T maxalso be same principle.
Specific embodiment (as Fig. 4 and Fig. 5):
One group is had to the battery pack of balanced intensity scarcely, wherein 1 joint monomer initial SOC is 0%, and all the other monomers are all 20%, ambient temperature 36 degree, when 2C charging is carried out to this Battery pack group, and the temperature curve of the most high monomer of temperature at the end of Fig. 4 is charging.Excess temperature when Fig. 4 shows that the unbalanced meeting of SOC to cause in battery pack the charging of Individual cells monomer, if do not adopt the method in the present invention, at the end of causing charging, temperature is more than 50 degree, namely exceedes the maximum operating temperature that man of Battery Plant specifies.Can have an impact to battery life and fail safe.
Utilize the method in the present invention, the maximum operation temperature in charging process can be effectively reduced after reducing charging current, avoid the danger brought because temperature is too high, as shown in Figure 5.Fig. 5 shows, have employed method of the present invention and estimates maximum temperature and maximum temperature difference in advance, thus the excess temperature avoiding causing because battery electric quantity is unbalanced when charging that restriction charging current can be preferential.
If not consider in battery charging process that battery electric quantity is unbalanced and heat-dissipating that is that cause is inconsistent, direct constant current is charged for different electricity monomer concerning battery pack, inconsistent according to the known heat-dissipating of above-mentioned analysis and temperature, long-term work can cause degree of aging inconsistent at the battery of temperature inconsistent state, and then affect battery pack whole service life, all will bring threat to battery pack safety and reliability.When considering the unbalanced impact brought temperature of battery pack, according to maximum operation temperature and maximum temperature difference two condition restriction battery operating temperature, thus obtain maximum charging current, effectively can reduce inconsistent due to electricity and in the charging process caused potential hazard.

Claims (1)

1. there is the charging method under the battery electric quantity imbalance of temperature protection function, it is characterized in that the method comprises the steps:
Step one: choose maximum SOC according to monomer remaining capacity SOC each in the battery pack obtained maxwith minimum SOC min, when charging to this battery pack, the charging interval can be expressed as:
t CHARGE = ( 1 - SOC max ) &CenterDot; C N I CHARGE
Wherein C nfor battery capacity, t cHARGEfor charging required time, I cHARGEfor charger constant current charge electric current;
Step 2: obtain the most high monomer of SOC and the minimum monomer of SOC t in charging process according to battery equation of heat balance and heat-dissipating, heat radiation equation cHARGEin time, I cHARGEtemperature under electric current at the end of charging represents with equation of heat balance:
mC p dT dt = H t in - H t out
Wherein m is monomer mass, C pbe battery thermal capacity, T is that (t is here the some moment represented in charging process to battery t, with charging total time t cHARGEan implication) temperature, represent battery heat-dissipating, represent battery heat radiation;
The following the Representation Equation of battery heat-dissipating:
H t in = &eta; t I CHARGE - I CHARGE T&Delta;S nF
η in heat-dissipating equation tfor overpotential, i.e. the difference of t battery terminal voltage and open circuit voltage, Δ S is the Entropy Changes in chemical reaction, and n is the electron amount participating in chemical reaction, and F is Faraday constant; Use equation show that Entropy Changes and the derivative of open circuit voltage to temperature exist certain relation;
The following the Representation Equation of battery heat transmission:
H t out = hA ( T - T a )
In heat radiation equation, h represents thermal transmission coefficient, and A is surface area, T afor ambient temperature;
Obtain thermal characteristics basic parameter: battery thermal capacity, conductive coefficient, then can solve in electric current I according to equation of heat balance, heat-dissipating and heat radiation three equations cHARGEany monomer temperature at any time in charging process:
T=f (I cHARGE, t, SOC) and t represents some moment,
Step 3, according in battery cell maximum temperature and battery pack between monomer maximum temperature difference provide restrictive condition:
In battery pack, any monomer any time maximum temperature is no more than the maximum temperature that handbook provides, T max<T def,
Temperature difference in battery pack arbitrarily between monomer is less than 5 degree, Δ T max<5 DEG C;
At the end of step 4, charging, namely the maximum electricity of t and the temperature of minimum amount of power battery cell should meet T max<T def, meanwhile, maximum electricity monomer and the maximum temperature difference of minimum amount of power monomer within the 0-t time period should meet Δ T max<5 DEG C, obtains I from these two restrictive conditions cHARGEi.e. maximum charging current.
CN201410680904.3A 2014-11-24 2014-11-24 A kind of charging method under the battery electric quantity imbalance with temperature protection function Active CN104409789B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410680904.3A CN104409789B (en) 2014-11-24 2014-11-24 A kind of charging method under the battery electric quantity imbalance with temperature protection function

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410680904.3A CN104409789B (en) 2014-11-24 2014-11-24 A kind of charging method under the battery electric quantity imbalance with temperature protection function

Publications (2)

Publication Number Publication Date
CN104409789A true CN104409789A (en) 2015-03-11
CN104409789B CN104409789B (en) 2016-08-24

Family

ID=52647396

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410680904.3A Active CN104409789B (en) 2014-11-24 2014-11-24 A kind of charging method under the battery electric quantity imbalance with temperature protection function

Country Status (1)

Country Link
CN (1) CN104409789B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106597314A (en) * 2017-01-16 2017-04-26 先进储能材料国家工程研究中心有限责任公司 Vehicle NI-MH power battery pack actual charge maintenance and corresponding voltage determination method
CN112526349A (en) * 2020-11-30 2021-03-19 北京航空航天大学 Whole vehicle energy management method based on battery state of charge and temperature joint estimation

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101264734A (en) * 2007-12-29 2008-09-17 奇瑞汽车股份有限公司 System protection control method for hybrid power automobile
JP2009296820A (en) * 2008-06-06 2009-12-17 Toyota Motor Corp Charge controller and charge controlling method for secondary battery, and electric vehicle

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101264734A (en) * 2007-12-29 2008-09-17 奇瑞汽车股份有限公司 System protection control method for hybrid power automobile
JP2009296820A (en) * 2008-06-06 2009-12-17 Toyota Motor Corp Charge controller and charge controlling method for secondary battery, and electric vehicle

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106597314A (en) * 2017-01-16 2017-04-26 先进储能材料国家工程研究中心有限责任公司 Vehicle NI-MH power battery pack actual charge maintenance and corresponding voltage determination method
CN106597314B (en) * 2017-01-16 2019-03-15 先进储能材料国家工程研究中心有限责任公司 The determination method of automobile-used Ni-MH power cell packet true charged holding and corresponding voltage
CN112526349A (en) * 2020-11-30 2021-03-19 北京航空航天大学 Whole vehicle energy management method based on battery state of charge and temperature joint estimation
CN112526349B (en) * 2020-11-30 2021-11-12 北京航空航天大学 Whole vehicle energy management method based on battery state of charge and temperature joint estimation

Also Published As

Publication number Publication date
CN104409789B (en) 2016-08-24

Similar Documents

Publication Publication Date Title
CN106208223B (en) Method for charging batteries and device
CN107894571B (en) Method for estimating service life of vehicle-mounted battery pack
CN104409788B (en) Preheating charge loss optimization method for charging battery pack under a kind of low temperature environment
CN101908775B (en) Charging control method and system of lithium ion battery pack
CN104505550A (en) Passive equalizing method and system for lithium iron phosphate battery pack
CN105633472A (en) Self-discharge rate consistency matching and screening method for lithium-ion battery
CN104333068A (en) Lithium battery charging control method, device and system and battery management system
CN107834620B (en) Multi-objective optimization control lithium battery pack charging method
Mamadou et al. The state-of-energy: A new criterion for the energetic performances evaluation of electrochemical storage devices
CN104951662A (en) Method for estimating SOE (State of Energy) of lithium iron phosphate battery
CN110085947A (en) A kind of quick self-heating method of battery cell, system and device
CN112820963B (en) Low-temperature charging method for lithium ion battery
CN204424402U (en) The passive equalizing system of ferric phosphate lithium cell group
Swierczynski et al. Investigation on the Self-discharge of the LiFePO 4/C nanophosphate battery chemistry at different conditions
CN104730464B (en) Method for testing adiabatic temperature rise rate of battery
CN107369858A (en) A kind of battery pack Bi-objective equalizing circuit control strategy stage by stage
CN105098272A (en) Safe charging method and apparatus for lithium secondary battery
CN104600381A (en) Optimization method for arrangement structures of lithium ion battery pack monomers
CN206364156U (en) A kind of Li-ion batteries piles heating system of high-energy-density
CN104409789A (en) Method for charging battery pack with temperature protection function in battery pack electric quantity unbalanced state
CN103312001B (en) Battery-charging method and system with super capacitor for energy storage system
Ruan et al. Stepwise segmented charging technique for lithium-ion battery to induce thermal management by low-temperature internal heating
CN107482265B (en) A kind of compound formulation of rate battery pack
CN103616644A (en) Method for evaluating properties of storage batteries in different types
CN104391251A (en) Data acquisition method of electric vehicle battery management system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant