Week 7 State of charge estimation
1.Simulate the 3 test cases from harness dashboard and write a detailed report on the results
2.What is coulomb counting? Refer to the above model and explain how BMS implements coulomb counting for SOC estimation ?
Hint :(Download the file from the link and go to SOC estimation model-ECU block)
Aim:
To simulate the 3 test cases from harnes dashboard and write a detailed report on the results.
To count coulomb and implement coloumb counting for SOC estimation.
From the above link the documentation should be downloaded
Harness
When simulation will start the model will be in driving condition,After 3000 seconds it will be in standby mode and after 1000 seconds it will be in charging mode.
Download and open closed loop BMS harness dashboard mode
From the plot we can see the vechicle is initially in driving state and charging was done till 90%.After charging it reaches to standby mode.It can be seen in BMS state plot.Battery temperature increases in driving and charging.Battery voltage was increased to 4.2 V while charging.Current plot shows the value of current supplied to vechicle while driving.SOC decreased uo to 50% in driving condition and it was increased while charging
From the graph shown in the 2nd case the fault condition occurs.After charging begins,the state of charge didnt increase.it continues to decrease.
soc is 100% in charging and remains in stand mode.
2.What is coulomb counting? Refer to the above model and explain how BMS implements coulomb counting for SOC estimation ?
coulomb counting:
it measures batteries discharge battery current and integrates current discharging over time to determine SOC,It is done to estimate current discharge in which previous discharge is found out
BMS SYSTEM is represented below
By clicking BMS ECU we get subsystem
by clicking soc estimation block
from clicking coloumb clicking method we get coloumb counting block
subsystem opens by clicking coloumb counting method:
advantage of coloumb counting method it is simple and low cost
temperature(c) and i(a) are inputs
current signal is given to a gain block and temperature is given to capacity since it varies according to temperature
inputs are given for integration where current will be integrated wrt time
output is given to another block it is divided by capacity.
hence soc is estimated