Week 7 State of charge estimation
1.Simulate the 3 test cases from harness dashboard and write a detailed report on the results
Now the download for link in 3 test cases from dashboard the link is already gave https://in.mathworks.com/matlabcentral/fileexchange/72865-design-and-test-lithium-ion-battery-management-algorithms
download and extract the file open for the plant in simulink model
select the test case 1on Test Sequence Variant Block
When the simulation will start the model will be in driving condition After 3000 seconds in standby mode and after 1000 seconds in charging mode.
OutPut:-
The vehicle in the plot initially in driving and charging done till 90%.After charging reaches to stand by mode.
BMS State plot Battery temperature increases in driving and charging and during charging time battery voltage increased to 4.2V
Current Plot is vehicle driving the value of current is supplied
SOC decreased up to 50% in driving condition & it was increased charging
Case:-2
the driving stages 0 to 10000seconds
Result:-
Fault condition occurred in second case.After charging was started,the SOC did not increase its continue to decrease
Case:-3
the charging stages 0 to 20000seconds
Result:-
The soc reached 100% in charging and remained in stand by mode. Cell temperature also decreased when standby mode was acheived.
2.What is coulomb counting? Refer to the above model and explain how BMS implements coulomb counting for SOC estimation ?
Coulomb counting is a technique used to track the State of Charge of a battery pack. It works by integrating the active flowing current over time to derive the total sum of energy entering or leaving the battery pack. This produces a capacity that is typically measured in Amp-hours.
coulomb counting method is its simplicity and low computational cost.
Temperature and current from the battery is given as inputs.
Current signal is given to a gain block and temperature is given to capacity since it varies according to temperature.
These inputs are given for integration where current will be integrated with respect to time.
This output is given to another block where it is divided by capacity.
Hence the SOC is estimated.