Week 7 State of charge estimation
Question 1
For the simulation of the model first down it from the mathworks site with the following link.
After downloding file extract it some of your folder.
After Running the BAttery project file Following page will open
there select design and test simulation.
the harness closed look board will look a like.
from 1 step you can select the test no 1 2 or 3.
in the BMS state resuest following block will appier similar for 1 2 and 3 will run the model test one bye one and observe the result in the scope.
parameters of the 1 test
.
here we can see driving is for 3000 sec second is the balancing for 1000 seconds and the third is charging and balancing at the same time for 5000 seconds.
following are the results.
in the image the white line no1 is the driving which we provide for 3000 sec
no2 line is standby mode
and charging start at 4000 sec for 5000 second,the charging start cell balancing also start see white line 4 the graph goes up.
in the soc section area when the driving model is on the soc is reduced ,see line no 5 , and when the charging is start the soc is increased
see line no 6 (white)
Now wiil run the sencond test with same procedure and observe the result.
in this mode only driving is simulated. for 10000 seconds
Follwoing are the result are observe.
Line no 1 white represent the rising of the temperature continously as the current is drwan from the battery.
line no2 state the driving mode
line no 4 no balancing is done when the vehicle is running, a straight line of 0
and line 3 tells about soc , as the vehicle is driving the soc of battery is falling down with respect to time .
Now will run the test no 3 as similar we done for 1 and 2 one.
following are the commands given and only charging takes place.
Following are the result of simulation.
As the charging take place the soc of battery goes from 0.8 to 1
the temperature of the cell goes on decreasing
and in the balancing area there a ripple in the end of the simulation that is because at starting battery is charged through constant current and then in constant volatge
so the cells are balancing their soc voltage and amp hour rating ,
Question 2
coulomb counting
Coulomb counting is a technique used to track the State of Charge of a battery pack.
he Coulomb counting method measures the discharging current of a battery and integrates the discharging current over time in order to estimate SOC
in the above model Coulomb counting is done by moethods
1 using the discreate time integer.
And the other is from Unsentenced Kalman filter. UKF and the Extended Kalman filter EKF
