CN107677965A - A kind of lithium battery energy state evaluation method - Google Patents
A kind of lithium battery energy state evaluation method Download PDFInfo
- Publication number
- CN107677965A CN107677965A CN201710859551.7A CN201710859551A CN107677965A CN 107677965 A CN107677965 A CN 107677965A CN 201710859551 A CN201710859551 A CN 201710859551A CN 107677965 A CN107677965 A CN 107677965A
- Authority
- CN
- China
- Prior art keywords
- battery
- energy
- stage
- discharge
- electric
- 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
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R31/3842—Arrangements for monitoring battery or accumulator variables, e.g. SoC combining voltage and current measurements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Secondary Cells (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
A kind of lithium battery energy state evaluation method, it comprises the following steps：Step 1, on the basis of electric energy, heat energy and off-energy is considered, establish the mathematics appraising model of lithium battery energy state；Step 2, discharged stage by stage using battery overall process electric discharge, the first stage is discharged under nonstandard design, and second stage is discharged under standard condition, obtains the electric energy of battery first stage and second stage electric discharge and the parameter of heat energy；The energy summation of step 3, the energy that battery first stage and second stage electric discharge release is calculated and overall process release；Step 4, using energy summation data carry out Function Fitting obtain battery maximum available energy EmaxAnd Eloss(I,T1) mathematic(al) representation；Step 5, above-mentioned parameter and expression formula substituted into step 1, real-time estimation is carried out to energy state SOE with reference to gathered data.The present invention obtains accurate lithium battery energy state in the case where having considered electric energy, heat energy and off-energy and battery power status estimation being influenceed.
Description
Technical field
The present invention relates to technical field of lithium batteries, and in particular to a kind of lithium battery energy state evaluation method.
Background technology
Battery status is typically characterized with battery dump energy, can be described from the angle of capacity or energy,
The former residual capacity accounts for the ratio of rated capacity, i.e. battery charge state (SOC)；The latter represents that remaining utilisable energy accounts for always
The ratio of energy, i.e. battery power status (SOE).Because SOC describes the situation of electric quantity change, while between terminal voltage
In the presence of stronger coupled relation, it is easy to cause larger prediction error when predicting the parameter directly related with power using SOC.And
SOE is then linearly related with power parameter, therefore in actual applications, and the continual mileage of battery, cruising time etc. are entered using SOE
Row is weighed and estimation, will be a kind of more accurate method.
On the one hand it is that computation model is inaccurate, battery is exchanged work but current battery energy state estimation precision is not still high
When condition is run, its electricity, thermal parameters change, and above-mentioned change does not obtain temporarily to off-energy caused by battery
More perfect consideration；On the other hand, the estimation of battery initial energy state does not form preferable scheme yet, causes current entirety
Estimation precision is still relatively low.
The content of the invention
It is an object of the invention to provide a kind of lithium battery energy state evaluation method, to solve the estimation of lithium battery energy state
The problem of inaccurate.
To achieve the above object, the present invention adopts the technical scheme that：
A kind of lithium battery energy state evaluation method, it comprises the following steps：
Step 1, the energy of lithium battery discharge process is divided into electric energy, heat energy and off-energy three parts, is considering electricity
On the basis of energy, heat energy and off-energy, the mathematics appraising model for establishing lithium battery energy state is：
Wherein, SOE (k) is current time battery power status, and SOE (k-1) is last moment battery power status, tk、
tk-1Respectively current time and last moment time value, u are battery terminal voltage, and i is discharge current and taken on the occasion of R is in battery
Resistance, EmaxFor battery maximum available energy, Eloss(i, T) be battery off-energy, Esum(i, T) be battery release electric energy and
The summation of heat energy；
Step 2, electric energy and heat energy parameter using battery overall process electric discharge acquisition battery：With discharge cut-off voltage a1V,
Upper limit cut-off temperature b1DEG C as electric discharge cut-off condition, discharge process is divided into two stages, first stage：Battery is put non-standard
Electric discharge records the electric energy of first stage battery and the parameter of heat energy up to reaching cut-off condition under electrician's condition；Second stage：First
After stage terminates, battery standing, treat that battery temperature recovers to rated temperature, battery discharge directly using standard electric discharge operating mode
To cut-off condition is reached, the electric energy and heat energy parameter of second stage battery are recorded；
Step 3, the parameter using above-mentioned electric energy and heat energy, respectively obtain at least two Battery packs first rank in discharge process
The electric energy W of section consumptione1(i, T) and heat energy Wh1(i, T), the electric energy W of second stage consumptione2(i, T) and heat energy Wh2(i, T), then
We1(i, T)=u1×i1×Δt (2)
Wh1(i, T)=i1 2×R1×Δt (3)
And obtain the energy of battery first stage release：
We2(i, T)=u2×i2×Δt (5)
Wh2(i, T)=i2 2×R2×Δt (6)
And obtain the energy of battery second stage release：
Total property of battery is：E (i, T)=Esum(i,T)+E'sum(i,T)
Wherein, Δ t=tk-tk-1, u1And i1Respectively the first stage when battery terminal voltage and discharge current, u2And i2Respectively
For second stage when battery terminal voltage and discharge current, internal resistance of cell R is the summation of battery ohmic internal resistance and polarization resistance；
Step 4, using at least two groups of E (i, T) data carry out Function Fittings, and obtain fitting function maximum E (i,
T)max,
So as to which battery maximum available energy is：Emax=E (i, T)max (8)
Then understand that battery is in T moment off-energies：
Eloss(I,T1)=Emax-Esum(I,T1) (9)；
Step 5, formula (4), (8) and (9) substituted into formula (1), you can obtain the energy state SOE (k) of T moment batteries.
Practice have shown that lithium battery, under different electric discharge operating modes, the electric energy and heat energy of its release simultaneously differ, and electric energy and heat
The summation of energy is also inconsistent, and this phenomenon explanation battery under partial discharge operating mode has energy loss, causes its maximum available
Energy can not be completely converted into electric energy and heat energy.The present invention can be reflected by the parameter of the introducing off-energy in appraising model
The influence of different discharge currents, varying environment temperature to energy state, electric energy, heat energy and off-energy have been considered to battery
The influence of energy state estimation, so as to obtain accurate lithium battery energy state.Meanwhile battery discharge is discharged using overall process
Method, and be fitted with two stage electric energy and heat energy to obtain battery maximum available energy, traditional rated energy parameter is modified,
Further increase the degree of accuracy of estimation.
The state that SOE is 100% is defined as battery fully charged state, namely under standard charging operating mode, after first constant current
Charging is carried out to battery for the mode of constant pressure until charging current is less than 0.02C, and it is 100% now to think SOE；SOE is 0% shape
State is defined as battery maximum available energy EmaxThe state all consumed.
As a modification of the present invention, battery initial energy state SOE (0) passes through the current state-of-charge SOC of battery
(0) obtain, its relational expression is：
SOE (0)=m × SOC (0)+n (10)
Wherein, m, n are the coefficient of coup of SOE and SOC curves.
Further, the detailed process of the first stage of the battery overall process electric discharge is：At a temperature of nominal environment, with
Discharge cut-off voltage a1V, upper limit cut-off temperature b1DEG C as electric discharge cut-off condition, battery is put under different discharge-rates
Electricity, electric discharge is until reach cut-off condition.
Further, the detailed process of the first stage of the battery overall process electric discharge is：Under nominal discharge multiplying power, with
Discharge cut-off voltage a1V, upper limit cut-off temperature b1DEG C as electric discharge cut-off condition, battery is put at different ambient temperatures
Electricity, electric discharge is until reach cut-off condition.
As a modification of the present invention, in the step 2 using battery overall process electric discharge obtain battery electric energy and
Heat energy parameter：The electric energy and heat energy gain of parameter mode of first Battery pack be：With discharge cut-off voltage a1V, upper limit cut-off temperature b1
DEG C as electric discharge cut-off condition, discharge process is divided into two stages, first stage：At a temperature of nominal environment, in different electric discharges
Battery is discharged under multiplying power, electric discharge records the electric energy of first stage battery and the parameter of heat energy up to reaching cut-off condition；
Second stage：After first stage terminates, battery standing, treat that battery temperature recovers to rated temperature, using standard electric discharge operating mode pair
Battery carries out electric discharge until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery；
The electric energy and heat energy gain of parameter mode of second Battery pack be：With discharge cut-off voltage a1V, upper limit cut-off temperature b1
DEG C as electric discharge cut-off condition, discharge process is divided into two stages, first stage：Under nominal discharge multiplying power, in varying environment
At a temperature of battery is discharged, electric discharge records the electric energy of first stage battery and the parameter of heat energy until reach cut-off condition；
Second stage：After first stage terminates, battery standing, treat that battery temperature recovers to rated temperature, using standard electric discharge operating mode pair
Battery carries out electric discharge until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery.
Compared with prior art, the present invention has advantages below：
The present invention can reflect different discharge currents, varying environment by the parameter of the introducing off-energy in appraising model
Influence of the temperature to energy state, what is influenceed is estimated on battery power status having considered electric energy, heat energy and off-energy
In the case of, obtain accurate lithium battery energy state；Meanwhile battery discharge uses overall process electric discharge, and with two stage electricity
It can be fitted to obtain battery maximum available energy with heat energy, traditional rated energy parameter is modified, further increases estimation
The degree of accuracy.
Brief description of the drawings
Fig. 1 is the flow chart of lithium battery energy state evaluation method of the present invention；
Fig. 2 is SOE and SOC connecting curve figure.
Embodiment
Present disclosure is described in further details with reference to the accompanying drawings and detailed description.It is appreciated that
It is that specific embodiment described herein is used only for explaining the present invention, rather than limitation of the invention.Further need exist for illustrating
, for the ease of description, part related to the present invention rather than full content are illustrate only in accompanying drawing.
The present invention can reflect different discharge currents, varying environment by the parameter of the introducing off-energy in appraising model
Influence of the temperature to energy state, what is influenceed is estimated on battery power status having considered electric energy, heat energy and off-energy
In the case of, obtain accurate lithium battery energy state.
The state that SOE is 100% is defined as battery fully charged state, namely under standard charging operating mode, after first constant current
Charging is carried out to battery for the mode of constant pressure until charging current is less than 0.02C, and it is 100% now to think SOE；SOE is 0% shape
State is defined as battery maximum available energy EmaxThe state all consumed.
Embodiment 1
Fig. 1 is refer to, a kind of lithium battery energy state evaluation method, it comprises the following steps：
Step 1, the energy of lithium battery discharge process is divided into electric energy, heat energy and off-energy three parts, is considering electricity
On the basis of energy, heat energy and off-energy, the mathematics appraising model for establishing lithium battery energy state is：
Wherein, SOE (k) is current time battery power status, and SOE (k-1) is last moment battery power status, tk、
tk-1Respectively current time and last moment time value, u are battery terminal voltage, and i is discharge current and taken on the occasion of R is in battery
Resistance, EmaxFor battery maximum available energy, Eloss(i, T) be battery off-energy, Esum(i, T) be battery release electric energy and
The summation of heat energy；
Wherein, in the present embodiment, battery initial energy state SOE (0) passes through the current state-of-charge SOC (0) of battery
Obtain, its relational expression is：
SOE (0)=m × SOC (0)+n (10)
M, n is the coefficient of coup of SOE and SOC curves.
Step 2, electric energy and heat energy parameter using battery overall process electric discharge acquisition battery：With discharge cut-off voltage a1V,
Upper limit cut-off temperature b1DEG C as electric discharge cut-off condition, discharge process is divided into two stages, first stage：Battery is put non-standard
Electric discharge records the electric energy of first stage battery and the parameter of heat energy up to reaching cut-off condition under electrician's condition；Second stage：First
After stage terminates, battery standing, treat that battery temperature recovers to rated temperature, battery discharge directly using standard electric discharge operating mode
To cut-off condition is reached, the electric energy and heat energy parameter of second stage battery are recorded；
In the present embodiment, the detailed process of the first stage of the battery overall process electric discharge is：In nominal environment temperature
Under, with discharge cut-off voltage a1V, upper limit cut-off temperature b1DEG C as electric discharge cut-off condition, battery is entered under different discharge-rates
Row electric discharge, electric discharge is until reach cut-off condition.
Step 3, the parameter using above-mentioned electric energy and heat energy, respectively obtain at least two Battery packs first rank in discharge process
The electric energy W of section consumptione1(i, T) and heat energy Wh1(i, T), and the electric energy W of discrete consuminge2(i, T) and heat energy Wh2(i, T), then
We1(i, T)=u1×i1×Δt (2)
Wh1(i, T)=i1 2×R1×Δt (3)
And obtain the energy of battery first stage release：
We2(i, T)=u2×i2×Δt (5)
Wh2(i, T)=i2 2×R2×Δt (6)
And obtain the energy of battery second stage release：
Total property of battery is：E (i, T)=Esum(i,T)+E'sum(i,T)
Wherein, Δ t=tk-tk-1, u1And i1Respectively the first stage when battery terminal voltage and discharge current, u2And i2Respectively
For second stage when battery terminal voltage and discharge current, internal resistance of cell R is the summation of battery ohmic internal resistance and polarization resistance.
Step 4, using at least two groups of E (i, T) data carry out Function Fittings, and obtain fitting function maximum E (i,
T)max,
So as to which battery maximum available energy is：Emax=E (i, T)max (8)
Then understand that battery is in T moment off-energies：
Eloss(I,T1)=Emax-Esum(I,T1) (9)；
Step 5, formula (4), (8) and (9) substituted into formula (1), you can obtain the energy state SOE (k) of T moment batteries.
Said process is explained below by way of specific example：It is 3.2V/20Ah's to choose a rated voltage/capacity
Ferric phosphate lithium cell is experimental subjects, and it is monitored by BMS, and it is 2V to set its discharge cut-off voltage, and upper limit cut-off is warm
Spend for 60 DEG C, it is allowed to which its maximum discharge current is 3C.
To obtain battery initial energy state SOE (0), it is necessary to determine lithium battery SOE and SOC corresponding relation first,
Its method is：Use standard recharging methods to battery carry out charging until reach fully charged state, it is specified that now battery SOE for
100%th, SOC 100%.Then in the case where standard discharges operating mode (discharge-rate 1/3C, environment temperature are 25 DEG C), battery is entered
Row electric discharge is until reach electric discharge cut-off condition.Percentage processing is carried out by the capacity to discharge process and energy datum, with SOC
As independent variable, SOE as dependent variable, SOE and SOC homologous thread is obtained as shown in Fig. 2 fitting obtains coefficient of coup m is
1.0374, n be -3.7508.Therefore, according to lithium battery SOC numerical value under current static condition, substitute into initial energy state and calculate public affairs
Formula, primary power SOE currency is obtained, the result of calculation represents percentages.Battery initial energy state is by standing shape
Battery charge state SOC under state is obtained, and effectively increases battery power status SOE estimation precision.
Then, using discharge-rate 1/3C, 25 DEG C of environment temperature as standard electric discharge operating mode, discharged using battery overall process
Method, discharge process are divided into two stages, first stage：It is 25 DEG C to set insulating box environment temperature, using discharge cut-off voltage as 2V,
Upper limit cut-off temperature is 60 DEG C and is used as cut-off condition of discharging, and 2.5C, 2C, 1.5C, 1C, 0.5C, 1/3C electric discharge times is respectively adopted
Rate is discharged, and records the electric energy of first stage battery and the parameter of heat energy；Second stage：After first stage terminates, battery
Stand, treat that battery temperature recovers to 25 DEG C, electric discharge is carried out to battery until reaching cut-off condition using standard electric discharge operating mode, recorded
The electric energy and heat energy parameter of second stage battery.
The experimental data obtained based on above-mentioned discharge process, with reference to sampling time interval and internal resistance of cell R (R power takings ponds
The summation of ohmic internal resistance and polarization resistance), according to formula：
We1(i, T)=u1×i1×Δt (2)
Wh1(i, T)=i1 2×R1×Δt (3)
Obtain the energy of battery first stage release：
According to formula：
We2(i, T)=u2×i2×Δt (5)
Wh2(i, T)=i2 2×R2×Δt (6)
Obtain the energy of battery second stage release：
The above-mentioned battery first stage is added with the energy that second stage discharges and obtains total property of battery and is：E
(i, T)=Esum(i,T)+E'sum(i,T).Function Fitting is carried out using at least two groups of E (i, T) data, and obtains fitting function
Maximum E (i, T)max, so as to which battery maximum available energy is：
Emax=E (i, T)max (8)
With reference to obtained EmaxAnd E under any operating modesum(I,T1) numerical value, battery is calculated corresponding to the operating mode and damages
Lose ENERGY Eloss(I,T1), then understand that battery is in T moment off-energies：
Eloss(I,T1)=Emax-Esum(I,T1) (9)
Initial energy state SOE (0), (4), (8) and (9) is substituted into formula (1), in integration time period section [tk,tk-1]
Voltage u, electric current i and temperature t interior, collected by BMS, real-time estimation is carried out to battery power status SOE, you can obtain
The energy state SOE (k) of T moment batteries.
Embodiment 2
The present embodiment difference from Example 1 is, in step 2, the first stage of the battery overall process electric discharge
Detailed process be：Under nominal discharge multiplying power, with discharge cut-off voltage a1V, upper limit cut-off temperature b1DEG C as electric discharge cut-off bar
Part, battery is discharged at different ambient temperatures, electric discharge is until reach cut-off condition.
Said process is explained below by way of specific example：It is 3.2V/20Ah's to choose a rated voltage/capacity
Ferric phosphate lithium cell is experimental subjects, and it is monitored by BMS, and it is 2V to set its discharge cut-off voltage, and upper limit cut-off is warm
Spend for 60 DEG C, it is allowed to which its maximum discharge current is 3C.
To obtain battery initial energy state SOE (0), it is necessary to determine lithium battery SOE and SOC corresponding relation first,
Its method is：Use standard recharging methods to battery carry out charging until reach fully charged state, it is specified that now battery SOE for
100%th, SOC 100%.Then in the case where standard discharges operating mode (discharge-rate 1/3C, environment temperature are 25 DEG C), battery is entered
Row electric discharge is until reach electric discharge cut-off condition.Percentage processing is carried out by the capacity to discharge process and energy datum, with SOC
As independent variable, SOE as dependent variable, SOE and SOC homologous thread is obtained as shown in Fig. 2 fitting obtains coefficient of coup m is
1.0374, n be -3.7508.Therefore, according to lithium battery SOC numerical value under current static condition, substitute into initial energy state and calculate public affairs
Formula, primary power SOE currency is obtained, the result of calculation represents percentages.
Then, using discharge-rate 1/3C, 25 DEG C of environment temperature as standard electric discharge operating mode, discharged using battery overall process
Method, discharge process are divided into two stages, first stage：The discharge-rate for setting battery is 3C, using discharge cut-off voltage as 2V, on
Cut-off temperature is limited as 60 DEG C as cut-off condition of discharging, 35 DEG C, 25 DEG C, 15 DEG C, 5 DEG C, 0 DEG C of environment temperature progress is respectively adopted
Electric discharge, and record the electric energy of first stage battery and the parameter of heat energy；Second stage：After first stage terminates, battery standing, treat
Battery temperature recovers to 25 DEG C, carries out electric discharge to battery until reaching cut-off condition using standard electric discharge operating mode, records second-order
The electric energy and heat energy parameter of section battery.
The experimental data obtained based on above-mentioned discharge process, with reference to sampling time interval and internal resistance of cell R (R power takings ponds
The summation of ohmic internal resistance and polarization resistance), according to formula：
We1(i, T)=u1×i1×Δt (2)
Wh1(i, T)=i1 2×R1×Δt (3)
Obtain the energy of battery first stage release：
According to formula：
We2(i, T)=u2×i2×Δt (5)
Wh2(i, T)=i2 2×R2×Δt (6)
Obtain the energy of battery second stage release：
The above-mentioned battery first stage is added with the energy that second stage discharges and obtains total property of battery and is：E
(i, T)=Esum(i,T)+E'sum(i,T).Function Fitting is carried out using at least two groups of E (i, T) data, and obtains fitting function
Maximum E (i, T)max, so as to which battery maximum available energy is：
Emax=E (i, T)max (8)
With reference to obtained EmaxAnd E under any operating modesum(I,T1) numerical value, battery is calculated corresponding to the operating mode and damages
Lose ENERGY Eloss(I,T1), then understand that battery is in T moment off-energies：
Eloss(I,T1)=Emax-Esum(I,T1) (9)
Initial energy state SOE (0), (4), (8) and (9) is substituted into formula (1), in integration time period section [tk,tk-1]
Voltage u, electric current i and temperature t interior, collected by BMS, real-time estimation is carried out to battery power status SOE, you can obtain
The energy state SOE (k) of T moment batteries.
Embodiment 3
It is as different from Example 1：The electric energy and heat of battery are obtained in the step 2 using battery overall process electric discharge
Can parameter：The electric energy and heat energy gain of parameter mode of first Battery pack be：With discharge cut-off voltage a1V, upper limit cut-off temperature b1℃
As electric discharge cut-off condition, discharge process is divided into two stages, first stage：At a temperature of nominal environment, in different electric discharges times
Battery is discharged under rate, electric discharge records the electric energy of first stage battery and the parameter of heat energy up to reaching cut-off condition；The
Two-stage：After first stage terminates, battery standing, treat that battery temperature recovers to rated temperature, operating mode is discharged to electricity using standard
Pond carries out electric discharge until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery；
The electric energy and heat energy gain of parameter mode of second Battery pack be：With discharge cut-off voltage a1V, upper limit cut-off temperature b1
DEG C as electric discharge cut-off condition, discharge process is divided into two stages, first stage：Under nominal discharge multiplying power, in varying environment
At a temperature of battery is discharged, electric discharge records the electric energy of first stage battery and the parameter of heat energy until reach cut-off condition；
Second stage：After first stage terminates, battery standing, treat that battery temperature recovers to rated temperature, using standard electric discharge operating mode pair
Battery carries out electric discharge until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery.
The electric energy of two Battery packs and heat energy parameter under Bu Tong non-standard electric discharge operating mode respectively by obtaining, then using upper
State two groups of E (i, T) data and carry out Function Fitting, and obtain the maximum E (i, T) of fitting functionmax, the battery now obtained is most
Available energy is than only more accurate by the battery maximum available energy for being fitted to obtain under single non-standard electric discharge operating mode.
Said process is explained below by way of specific example：It is 3.2V/20Ah's to choose a rated voltage/capacity
Ferric phosphate lithium cell is experimental subjects, and it is monitored by BMS, and it is 2V to set its discharge cut-off voltage, and upper limit cut-off is warm
Spend for 60 DEG C, it is allowed to which its maximum discharge current is 3C.
To obtain battery initial energy state SOE (0), it is necessary to determine lithium battery SOE and SOC corresponding relation first,
Its method is：Use standard recharging methods to battery carry out charging until reach fully charged state, it is specified that now battery SOE for
100%th, SOC 100%.Then in the case where standard discharges operating mode (discharge-rate 1/3C, environment temperature are 25 DEG C), battery is entered
Row electric discharge is until reach electric discharge cut-off condition.Percentage processing is carried out by the capacity to discharge process and energy datum, with SOC
As independent variable, SOE as dependent variable, SOE and SOC homologous thread is obtained as shown in Fig. 2 fitting obtains coefficient of coup m is
1.0374, n be -3.7508.Therefore, according to lithium battery SOC numerical value under current static condition, substitute into initial energy state and calculate public affairs
Formula, primary power SOE currency is obtained, the result of calculation represents percentages.
Then, the electric energy of the first Battery pack and heat energy gain of parameter mode are：With 25 DEG C of discharge-rate 1/3C, environment temperature
As standard electric discharge operating mode, using battery overall process electric discharge, discharge process is divided into two stages, first stage：Constant temperature is set
Case environment temperature is 25 DEG C, and using discharge cut-off voltage as 2V, upper limit cut-off temperature is 60 DEG C and is used as cut-off condition of discharging, and adopts respectively
Discharged with 2.5C, 2C, 1.5C, 1C, 0.5C, 1/3C discharge-rate, and record the electric energy and heat energy of first stage battery
Parameter；Second stage：After first stage terminates, battery standing, treat that battery temperature recovers to 25 DEG C, using standard electric discharge operating mode
Electric discharge is carried out to battery until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery.
The electric energy and heat energy gain of parameter mode of second Battery pack be：Using discharge-rate 1/3C, 25 DEG C of environment temperature as
Standard electric discharge operating mode, using battery overall process electric discharge, discharge process is divided into two stages, first stage：Putting for battery is set
Electric multiplying power is 3C, and using discharge cut-off voltage as 2V, upper limit cut-off temperature is 60 DEG C and is used as cut-off condition of discharging, and is respectively adopted 35
DEG C, 25 DEG C, 15 DEG C, 5 DEG C, 0 DEG C of environment temperature discharged, and records the electric energy of first stage battery and the parameter of heat energy；
Second stage：After first stage terminates, battery standing, treat that battery temperature recovers to 25 DEG C, operating mode is discharged to battery using standard
Electric discharge is carried out until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery.
The experimental data obtained based on above-mentioned discharge process, with reference to sampling time interval and internal resistance of cell R (R power takings ponds
The summation of ohmic internal resistance and polarization resistance), according to formula：
We1(i, T)=u1×i1×Δt (2)
Wh1(i, T)=i1 2×R1×Δt (3)
Obtain the energy of battery first stage release：
According to formula：
We2(i, T)=u2×i2×Δt (5)
Wh2(i, T)=i2 2×R2×Δt (6)
Obtain the energy of battery second stage release：
The above-mentioned battery first stage is added with the energy that second stage discharges and obtains total property of battery and is：E
(i, T)=Esum(i,T)+E'sum(i,T).Function Fitting is carried out using two groups of E (i, T) data, and obtains the maximum of fitting function
Value E (i, T)max, so as to which battery maximum available energy is：
Emax=E (i, T)max (8)
With reference to obtained EmaxAnd E under any operating modesum(I,T1) numerical value, battery is calculated corresponding to the operating mode and damages
Lose ENERGY Eloss(I,T1), then understand that battery is in T moment off-energies：
Eloss(I,T1)=Emax-Esum(I,T1) (9)
Initial energy state SOE (0), (4), (8) and (9) is substituted into formula (1), in integration time period section [tk,tk-1]
Voltage u, electric current i and temperature t interior, collected by BMS, real-time estimation is carried out to battery power status SOE, you can obtain
The energy state SOE (k) of T moment batteries.
Above-described embodiment only not limits the technical scheme described by this patent to illustrate this patent；Therefore, although
This specification has been carried out being described in detail with reference to above-mentioned each embodiment to this patent, still, the ordinary skill of this area
Personnel should be appreciated that and still this patent can be modified or equivalent substitution；And all do not depart from this patent spirit and
The technical scheme of scope and its improvement, it all should cover among the right of this patent.
Claims (6)
1. a kind of lithium battery energy state evaluation method, it is characterised in that comprise the following steps：
Step 1, the energy of lithium battery discharge process is divided into electric energy, heat energy and off-energy three parts, is considering electric energy, heat
Can be with the basis of off-energy, the mathematics appraising model for establishing lithium battery energy state is：
<mrow>
<mi>S</mi>
<mi>O</mi>
<mi>E</mi>
<mrow>
<mo>(</mo>
<mi>k</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mi>S</mi>
<mi>O</mi>
<mi>E</mi>
<mrow>
<mo>(</mo>
<mi>k</mi>
<mo>-</mo>
<mn>1</mn>
<mo>)</mo>
</mrow>
<mo>-</mo>
<msubsup>
<mo>&Integral;</mo>
<msub>
<mi>t</mi>
<mrow>
<mi>k</mi>
<mo>-</mo>
<mn>1</mn>
</mrow>
</msub>
<msub>
<mi>t</mi>
<mi>k</mi>
</msub>
</msubsup>
<mfrac>
<mrow>
<msup>
<mi>i</mi>
<mn>2</mn>
</msup>
<mi>R</mi>
<mo>+</mo>
<mi>u</mi>
<mi>i</mi>
</mrow>
<msub>
<mi>R</mi>
<mi>max</mi>
</msub>
</mfrac>
<mo>&times;</mo>
<mfrac>
<mrow>
<msub>
<mi>E</mi>
<mrow>
<mi>l</mi>
<mi>o</mi>
<mi>s</mi>
<mi>s</mi>
</mrow>
</msub>
<mrow>
<mo>(</mo>
<mi>i</mi>
<mo>,</mo>
<mi>T</mi>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>E</mi>
<mrow>
<mi>s</mi>
<mi>u</mi>
<mi>m</mi>
</mrow>
</msub>
<mrow>
<mo>(</mo>
<mi>i</mi>
<mo>,</mo>
<mi>T</mi>
<mo>)</mo>
</mrow>
</mrow>
</mfrac>
<mi>d</mi>
<mi>u</mi>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>)</mo>
</mrow>
</mrow>
Wherein, SOE (k) is current time battery power status, and SOE (k-1) is last moment battery power status, tk、tk-1Point
Not Wei current time and last moment time value, u is battery terminal voltage, i be discharge current and take on the occasion of, R is the internal resistance of cell,
EmaxFor battery maximum available energy, Eloss(i, T) be battery off-energy, Esum(i, T) is the electric energy and heat of battery release
The summation of energy；
Step 2, electric energy and heat energy parameter using battery overall process electric discharge acquisition battery：With discharge cut-off voltage a1V, the upper limit
Cut-off temperature b1DEG C as electric discharge cut-off condition, discharge process is divided into two stages, first stage：Battery is in non-standard electric discharge work
Electric discharge records the electric energy of first stage battery and the parameter of heat energy up to reaching cut-off condition under condition；Second stage：First stage
After end, battery standing, treat that battery temperature recovers to rated temperature, battery discharge until reaching using standard electric discharge operating mode
To cut-off condition, the electric energy and heat energy parameter of record second stage battery；
Step 3, the parameter using above-mentioned electric energy and heat energy, respectively obtaining at least two Battery packs first stage in discharge process disappears
The electric energy W of consumptione1(i, T) and heat energy Wh1(i, T), the electric energy W of second stage consumptione2(i, T) and heat energy Wh2(i, T), then
We1(i, T)=u1×i1×Δt (2)
Wh1(i, T)=i1 2×R1×Δt (3)
And obtain the energy of battery first stage release：
We2(i, T)=u2×i2×Δt (5)
Wh2(i, T)=i2 2×R2×Δt (6)
And obtain the energy of battery second stage release：
Total property of battery is：E (i, T)=Esum(i,T)+E'sum(i,T)
Wherein, Δ t=tk-tk-1, u1And i1Respectively the first stage when battery terminal voltage and discharge current, u2And i2Respectively
Battery terminal voltage and discharge current during the two-stage, internal resistance of cell R are the summation of battery ohmic internal resistance and polarization resistance；
Step 4, utilize at least two groups of E (i, T) data progress Function Fittings, and obtain the maximum E (i, T) of fitting functionmax,
So as to which battery maximum available energy is：Emax=E (i, T)max (8)
Then understand that battery is in T moment off-energies：
Eloss(I,T1)=Emax-Esum(I,T1) (9)；
Step 5, formula (4), (8) and (9) substituted into formula (1), you can obtain the energy state SOE (k) of T moment batteries.
2. lithium battery energy state evaluation method according to claim 1, it is characterised in that：The state that SOE is 100% is determined
Justice is battery fully charged state, namely under standard charging operating mode, battery charge directly by the way of constant pressure after first constant current
It is less than 0.02C to charging current, it is 100% now to think SOE；The state that SOE is 0% is defined as battery maximum available energy
EmaxThe state all consumed.
3. lithium battery energy state evaluation method according to claim 1, it is characterised in that：Battery initial energy state
SOE (0) is obtained by the current state-of-charge SOC (0) of battery, and its relational expression is：
SOE (0)=m × SOC (0)+n (10)
Wherein, m, n are the coefficient of coup of SOE and SOC curves.
4. lithium battery energy state evaluation method according to claim 1, it is characterised in that：The battery overall process electric discharge
The detailed process of first stage be：At a temperature of nominal environment, battery is discharged under different discharge-rates, electric discharge is straight
To reaching cut-off condition.
5. lithium battery energy state evaluation method according to claim 1, it is characterised in that：The battery overall process electric discharge
The detailed process of first stage be：Under nominal discharge multiplying power, battery is discharged at different ambient temperatures, electric discharge is straight
To reaching cut-off condition.
6. lithium battery energy state evaluation method according to claim 1, it is characterised in that：Using electricity in the step 2
Pond overall process electric discharge obtains the electric energy and heat energy parameter of battery：The electric energy and heat energy gain of parameter mode of first Battery pack be：
With discharge cut-off voltage a1V, upper limit cut-off temperature b1DEG C as electric discharge cut-off condition, discharge process is divided into two stages, the first rank
Section：At a temperature of nominal environment, battery is discharged under different discharge-rates, electric discharge records up to reaching cut-off condition
The electric energy of first stage battery and the parameter of heat energy；Second stage：After first stage terminates, battery standing, treat that battery temperature is extensive
Again to rated temperature, electric discharge is carried out to battery until reaching cut-off condition using standard electric discharge operating mode, records second stage battery
Electric energy and heat energy parameter；
The electric energy and heat energy gain of parameter mode of second Battery pack be：With discharge cut-off voltage a1V, upper limit cut-off temperature b1DEG C make
For cut-off condition of discharging, discharge process is divided into two stages, first stage：Under nominal discharge multiplying power, in varying environment temperature
Under battery is discharged, electric discharge records the electric energy of first stage battery and the parameter of heat energy until reach cut-off condition；Second
Stage：After first stage terminates, battery standing, treat that battery temperature recovers to rated temperature, operating mode is discharged to battery using standard
Electric discharge is carried out until reaching cut-off condition, records the electric energy and heat energy parameter of second stage battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710859551.7A CN107677965B (en) | 2017-09-21 | 2017-09-21 | A kind of lithium battery energy state evaluation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710859551.7A CN107677965B (en) | 2017-09-21 | 2017-09-21 | A kind of lithium battery energy state evaluation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107677965A true CN107677965A (en) | 2018-02-09 |
| CN107677965B CN107677965B (en) | 2019-10-18 |
Family
ID=61136835
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710859551.7A Active CN107677965B (en) | 2017-09-21 | 2017-09-21 | A kind of lithium battery energy state evaluation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107677965B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109541479A (en) * | 2018-10-26 | 2019-03-29 | 东软睿驰汽车技术（沈阳）有限公司 | A kind of predictor method and device of battery remaining power |
| CN110231577A (en) * | 2019-06-14 | 2019-09-13 | 安徽锐能科技有限公司 | A kind of SOE estimation device for mending electric-type active equalization based on battery |
| CN110596594A (en) * | 2019-09-23 | 2019-12-20 | 广东毓秀科技有限公司 | Method for predicting SOE of rail-traffic lithium battery through big data |
| CN111308354A (en) * | 2020-03-11 | 2020-06-19 | 深圳易马达科技有限公司 | Method and device for detecting state of health of battery, electronic equipment and storage medium |
| CN111611669A (en) * | 2019-02-22 | 2020-09-01 | 清华大学 | Battery safety improvement method and device, computer equipment and storage medium |
| CN112858924A (en) * | 2019-11-28 | 2021-05-28 | 比亚迪股份有限公司 | Method and device for estimating residual energy of power battery, vehicle and storage medium |
| CN113253117A (en) * | 2021-05-28 | 2021-08-13 | 雅迪科技集团有限公司 | Estimation method and estimation device for residual SOE value |
| CN113848496A (en) * | 2021-11-08 | 2021-12-28 | 东软睿驰汽车技术（沈阳）有限公司 | Performance determination method and device of power battery and electronic equipment |
| CN116540115A (en) * | 2023-06-30 | 2023-08-04 | 云南丁旺科技有限公司 | Battery energy state monitoring method and battery system |
| CN117890798A (en) * | 2024-03-14 | 2024-04-16 | 深圳海辰储能科技有限公司 | Battery remaining energy state estimation method and related device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439668A (en) * | 2013-09-05 | 2013-12-11 | 桂林电子科技大学 | Charge state evaluation method and system of power lithium ion battery |
| CN104459551A (en) * | 2014-11-28 | 2015-03-25 | 山东理工大学 | Electric vehicle power battery state-of-energy estimation method |
| CN104951662A (en) * | 2015-07-16 | 2015-09-30 | 中国科学院广州能源研究所 | Method for estimating SOE (State of Energy) of lithium iron phosphate battery |
| CN105068011A (en) * | 2015-07-29 | 2015-11-18 | 中国汽车技术研究中心 | Method for estimating and correcting lithium manganate series battery pack SOC value |
-
2017
- 2017-09-21 CN CN201710859551.7A patent/CN107677965B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439668A (en) * | 2013-09-05 | 2013-12-11 | 桂林电子科技大学 | Charge state evaluation method and system of power lithium ion battery |
| CN104459551A (en) * | 2014-11-28 | 2015-03-25 | 山东理工大学 | Electric vehicle power battery state-of-energy estimation method |
| CN104951662A (en) * | 2015-07-16 | 2015-09-30 | 中国科学院广州能源研究所 | Method for estimating SOE (State of Energy) of lithium iron phosphate battery |
| CN105068011A (en) * | 2015-07-29 | 2015-11-18 | 中国汽车技术研究中心 | Method for estimating and correcting lithium manganate series battery pack SOC value |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109541479A (en) * | 2018-10-26 | 2019-03-29 | 东软睿驰汽车技术（沈阳）有限公司 | A kind of predictor method and device of battery remaining power |
| CN111611669A (en) * | 2019-02-22 | 2020-09-01 | 清华大学 | Battery safety improvement method and device, computer equipment and storage medium |
| CN111611669B (en) * | 2019-02-22 | 2024-01-23 | 清华大学 | Battery safety improvement method, device, computer equipment and storage medium |
| CN110231577A (en) * | 2019-06-14 | 2019-09-13 | 安徽锐能科技有限公司 | A kind of SOE estimation device for mending electric-type active equalization based on battery |
| CN110596594A (en) * | 2019-09-23 | 2019-12-20 | 广东毓秀科技有限公司 | Method for predicting SOE of rail-traffic lithium battery through big data |
| CN112858924B (en) * | 2019-11-28 | 2023-06-13 | 比亚迪股份有限公司 | Power battery remaining energy estimation method, device, vehicle and storage medium |
| CN112858924A (en) * | 2019-11-28 | 2021-05-28 | 比亚迪股份有限公司 | Method and device for estimating residual energy of power battery, vehicle and storage medium |
| CN111308354A (en) * | 2020-03-11 | 2020-06-19 | 深圳易马达科技有限公司 | Method and device for detecting state of health of battery, electronic equipment and storage medium |
| CN113253117A (en) * | 2021-05-28 | 2021-08-13 | 雅迪科技集团有限公司 | Estimation method and estimation device for residual SOE value |
| CN113253117B (en) * | 2021-05-28 | 2023-10-13 | 雅迪科技集团有限公司 | Estimation method and estimation device for residual SOE value |
| CN113848496A (en) * | 2021-11-08 | 2021-12-28 | 东软睿驰汽车技术（沈阳）有限公司 | Performance determination method and device of power battery and electronic equipment |
| CN116540115A (en) * | 2023-06-30 | 2023-08-04 | 云南丁旺科技有限公司 | Battery energy state monitoring method and battery system |
| CN116540115B (en) * | 2023-06-30 | 2023-09-26 | 云南丁旺科技有限公司 | Battery energy state monitoring method and battery system |
| CN117890798A (en) * | 2024-03-14 | 2024-04-16 | 深圳海辰储能科技有限公司 | Battery remaining energy state estimation method and related device |
| CN117890798B (en) * | 2024-03-14 | 2024-05-14 | 深圳海辰储能科技有限公司 | Battery remaining energy state estimation method and related device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107677965B (en) | 2019-10-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107677965A (en) | A kind of lithium battery energy state evaluation method | |
| CN107991623B (en) | Battery ampere-hour integral SOC estimation method considering temperature and aging degree | |
| CN106909716B (en) | Lithium iron phosphate battery modeling and SOC estimation method considering capacity loss | |
| CN106716158B (en) | Battery charge state evaluation method and device | |
| CN107533105B (en) | Lithium ion battery state of charge estimation method and device | |
| CN110031770B (en) | Method for rapidly obtaining capacity of all single batteries in battery pack | |
| CN111239611B (en) | Calculation method for calibrating PACKSOC based on single battery capacity | |
| CN103020445B (en) | A kind of SOC and SOH Forecasting Methodology of electric-vehicle-mounted ferric phosphate lithium cell | |
| CN101814640B (en) | CC-CV charging method for improved power lithium ion battery | |
| CN105954679B (en) | A kind of On-line Estimation method of lithium battery charge state | |
| JP5466564B2 (en) | Battery degradation estimation method, battery capacity estimation method, battery capacity equalization method, and battery degradation estimation apparatus | |
| CN104951662B (en) | A kind of ferric phosphate lithium cell energy state SOE evaluation method | |
| CN107247235A (en) | A kind of battery capacity evaluation method for considering batteries in parallel connection difference | |
| CN104678316A (en) | Method and device for estimating charge state of lithium ion battery | |
| CN105223487B (en) | A kind of multimode decoupling method of estimation of lithium ion battery | |
| CN113253140A (en) | Battery health state online estimation method | |
| CN101975927A (en) | Method and system for estimating remaining available capacity of lithium ion power battery pack | |
| CN109541485A (en) | A kind of SOC estimation method of power battery | |
| CN105116350B (en) | SOC variable quantities and discharge electricity amount conversion factor measuring method when power battery discharges | |
| Purwadi et al. | State of Charge estimation method for lithium battery using combination of Coulomb Counting and Adaptive System with considering the effect of temperature | |
| CN108508370A (en) | A kind of open-circuit voltage based on temperature correction-ampere-hour integral SOC methods of estimation | |
| CN105717455A (en) | Selection method for single battery SOC (State of Charge) and capacity estimation algorithm of battery pack | |
| CN103135066A (en) | Measuring method of electric quantity of segmented iron phosphate lithium battery | |
| CN110596604A (en) | Lithium battery SOC estimation method based on ampere-hour integration method | |
| CN112305426A (en) | Lithium ion battery power state estimation system under multi-constraint condition |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |