CN107861075A

CN107861075A - A kind of method for determining electrokinetic cell SOP

Info

Publication number: CN107861075A
Application number: CN201711412872.9A
Authority: CN
Inventors: 李世明; 王世强; 胡庆军; 张叶鑫
Original assignee: Jiangxi Special Automobile Technology Co Ltd
Current assignee: Jiangxi Special Automobile Technology Co Ltd
Priority date: 2017-12-24
Filing date: 2017-12-24
Publication date: 2018-03-30
Anticipated expiration: 2037-12-24
Also published as: CN107861075B

Abstract

Present invention is disclosed a kind of method for determining electrokinetic cell SOP：Step 1, the temperature of selected measurement target, polarizing voltage, duration, SOC, SOH；Step 2, battery is adjusted to the temperature to target, SOC and SOH；Step 3, the starting polarizing voltage that battery is adjusted to target；Step 4, obtain the electric discharge coulombic efficiency for specifying setting time under multiplying power；Step 5, obtain the charging coulombic efficiency specified and the duration is selected under multiplying power；Step 6, step 4,5 results obtained carry out curve, toroidal function fitting；Step 7, the cell damage assessment that power is given under specified criteria is obtained according to fitting result, power can be born by obtaining the maximum of battery.The advantage of the invention is that assessing battery capacity loss using coulombic efficiency direct quantitative, reliable basis can be provided using the power of battery for control strategy, starting polarizing voltage condition is set, contains influence of the usage history to SOP so that measurement is more accurately and reliably.

Description

A kind of method for determining electrokinetic cell SOP

Technical field

The present invention relates to electric automobile field, more particularly to electric automobile power battery management domain.

Background technology

Due to the aggravation of energy crisis and environmental crisis, new-energy automobile has obtained rapid development this year, and lithium battery As the main flow energy storage energy of electric automobile, its management system has also obtained extensive concern.In battery management, the state of battery Parameter SOC (dump energy), SOH (residual life), SOP (power bearing ability) are critically important state parameters, SOC and SOH technological development obtains, extensive concern.But for lithium battery power bearing ability (state of power, SOP real-time estimation) can be seldom with technology.SOP represents battery to the ability to bear of charge-discharge electric power, SOP accurate estimation Can be on the premise of battery be protected, allowing electric automobile to obtain, bigger power is free, such as the available horsepower accelerated that starts to walk, and climbs The speed on slope, the recoverable power of brake electricity etc..The power rating of battery with many factors such as SOC, SOH of battery, temperature and State has relation, therefore the nonlinear characteristic with height.

Prior art mainly has the method for impulse response, such as U.S. on the Forecasting Methodology of power of battery ability to bear Freedo-CAR projects《Power auxiliary type Hybrid Vehicle electrokinetic cell handbook》(abbreviation HPPC), by battery Apply certain pulses excitation under different SOC, obtain corresponding voltage accordingly to carry out power prediction, but this method is only examined The static nature of battery is considered, the precision of prediction in dynamic operation condition is very low.Electrochemical model method, it is partially micro- using a large amount of chemistry Point, estimated using various approximate combinations, but the scope of application after simplifying is very limited, it is difficult to meet the requirement of application.Electricity Model is combined come the behavior of simulated battery by electricity component, but estimates that these models, which are more suitable for performance, to be imitated compared to SOP Very.Some other method of prior art, such as patent application 201610799603.1, peak power is a priori obtained, still But the not specific method for obtaining peak power.

The content of the invention

The technical problems to be solved by the invention are to realize that a kind of maximum that can reliably, effectively determine electrokinetic cell can be held By power.

To achieve these goals, the technical solution adopted by the present invention is：A kind of method for determining electrokinetic cell SOP：

Step 1, the temperature of selected measurement target, polarizing voltage, duration, SOC, SOH；

Step 2, battery is adjusted to the temperature to target, SOC and SOH；

Step 3, the starting polarizing voltage that battery is adjusted to target；

Step 4, obtain the electric discharge coulombic efficiency for specifying setting time under multiplying power；

Step 5, obtain the charging coulombic efficiency specified and the duration is selected under multiplying power；

Step 6, step 4,5 results obtained carry out curve, toroidal function fitting；

Step 7, the cell damage assessment that power is given under specified criteria is obtained according to fitting result, obtain the maximum of battery Power can be born.

Target temperature point in the step 1, selected is 0 DEG C, 5 DEG C, 10 DEG C, 20 DEG C, 35 DEG C, 45 DEG C, 50 DEG C, 55 DEG C；

In the step 1, selected target SOC points are 10%, 20%, 30%, 50%, 80%, 90%, 100%.

In the step 1, selected target SOH is 100%, 90%, 85%, 80%, 70%.The selected duration is 10 Second, 20 seconds, 35 seconds.

In the step 1, selected target polarizing voltage is fully charged by standard condition, respectively using the nominal cycle life-span times Rate, 80% cycle life multiplying power, 50% cycle life multiplying power, 30% cycle life multiplying power are discharged battery, polarized Voltage curve, to should the polarizing voltages of SOC points be chosen to be test polarizing voltage.

The setting time of the step 4 is 20 seconds.

The step 5 obtains charging coulombic efficiency by repeat step 1,2, repeats to select different parameters, then pin every time The selected duration under multiplying power is specified to obtain charging coulombic efficiency to measuring the point.

The step 4 obtains electric discharge coulombic efficiency by repeat step 1-3, repeats to select different parameters every time, measures Each selected temperature, SOC, SOH and the selected duration under starting polarizing voltage charging coulombic efficiency and electric discharge coulomb effect Rate.

The advantage of the invention is that assessing battery capacity loss using coulombic efficiency direct quantitative, can make for control strategy Reliable basis are provided with the power of battery, starting polarizing voltage condition is set, contains influence of the usage history to SOP so that is surveyed More accurately and reliably, battery can select the peak power of variation using strategy to amount on the premise of battery capacity overall loss is controlled Control strategy.

Brief description of the drawings

The content of every width accompanying drawing expression in description of the invention is briefly described below：

Fig. 1 is the flow chart for the method for determining electrokinetic cell SOP.

Embodiment

Present invention determine that electrokinetic cell SOP method, is that a kind of maximum that can inherently determine battery can bear work( The method of rate, by taking ternary lithium battery 8Ah battery cores as an example, specific processing step is as follows：

Step 1：Selected temperature point is 0 DEG C, 5 DEG C, 10 DEG C, 20 DEG C, 35 DEG C, 45 DEG C, 50 °C, 55 DEG C；

Selected SOC points are 10%, 20%, 30%, 50%, 80%, 90%, 100%.Selected SOH is 100%, 90%, 85%, 80%, 70%；

The selected duration is 10 seconds, 20 seconds, 35 seconds.Selecting for polarizing voltage, it is fully charged by standard condition, use respectively Nominal cycle life-span multiplying power, 80% cycle life multiplying power, 50% cycle life multiplying power, 30% cycle life multiplying power are carried out to battery Electric discharge, obtains polarizing voltage curve, to should the polarizing voltages of SOC points be chosen to be test polarizing voltage.

Step 2：Battery is adjusted into the temperature to target, SOC and SOH.

Step 3: battery is adjusted to the starting polarizing voltage of target.

Step 4: measuring the point specifies 20 seconds under the multiplying power coulombic efficiencies that discharge.

Step 5: repeat step one or two, measures the charging coulombic efficiency that the point specifies the selected duration under multiplying power.

Step 6: repeat step one to four, measures each selected temperature, SOC, SOH and originates selected under polarizing voltage The charging coulombic efficiency and electric discharge coulombic efficiency of duration.

Step 7: according to above-mentioned test result, the Function Fittings such as curve and surface are carried out.

Step 8: according to fitting result, the battery capacity decay Risk assessment that power is given under specified criteria, power supply are designed Pond charge and discharge control strategy use.

Claims

A kind of 1. method for determining electrokinetic cell SOP, it is characterised in that：

Step 1, the temperature of selected measurement target, polarizing voltage, duration, SOC, SOH；

Step 2, battery is adjusted to the temperature to target, SOC and SOH；

Step 3, the starting polarizing voltage that battery is adjusted to target；

Step 4, obtain the electric discharge coulombic efficiency for specifying setting time under multiplying power；

Step 5, obtain the charging coulombic efficiency specified and the duration is selected under multiplying power；

Step 6, step 4,5 results obtained carry out curve, toroidal function fitting；

Step 7, the cell damage assessment that power is given under specified criteria is obtained according to fitting result, obtaining the maximum of battery can hold By power.
2. the method according to claim 1 for determining electrokinetic cell SOP, it is characterised in that：In the step 1, it is selected Target temperature point is 0 DEG C, 5 DEG C, 10 DEG C, 20 DEG C, 35 DEG C, 45 DEG C, 50 DEG C, 55 DEG C.
3. the method according to claim 1 for determining electrokinetic cell SOP, it is characterised in that：It is selected in the step 1 Target SOC points are 10%, 20%, 30%, 50%, 80%, 90%, 100%.
4. the method according to claim 1 for determining electrokinetic cell SOP, it is characterised in that：It is selected in the step 1 Target SOH is 100%, 90%, 85%, 80%, 70%.The selected duration is 10 seconds, 20 seconds, 35 seconds.
5. the method according to claim 1 for determining electrokinetic cell SOP, it is characterised in that：It is selected in the step 1 Target polarizing voltage is fully charged by standard condition, and respectively using nominal cycle life-span multiplying power, 80% cycle life multiplying power, 50% follows Ring life-span multiplying power, 30% cycle life multiplying power are discharged battery, obtain polarizing voltage curve, to should SOC points polarization Voltage is chosen to be test polarizing voltage.
6. the determined power battery SOP method really according to any one of claim 1-5, it is characterised in that：The step 4 Setting time be 20 seconds.
7. the method according to claim 6 for determining electrokinetic cell SOP, it is characterised in that：The step 5 is walked by repeating Rapid 1,2 obtain charging coulombic efficiencies, repeat to select different parameters every time, then selected are held for measure that the point specifies under multiplying power The continuous time obtains charging coulombic efficiency.
8. the determined power battery SOP method really according to claim 1 or 7, it is characterised in that：The step 4 passes through weight Multiple step 1-3 obtains electric discharge coulombic efficiency, repeats to select different parameters every time, measures each selected temperature, SOC, SOH and rises The charging coulombic efficiency and electric discharge coulombic efficiency of selected duration under beginning polarizing voltage.