Week-4 Challenge WOT Condition Part-2
1. Difference between mapped and dynamic model of engine, motor and generator?
Mapped Model:-
1. Mapped engines represent macro engine behavior as a set of lookup tables(brake torque, fuel flow, air mass flow, exhaust temperature, efficiency and emissions) as functions of commanded load and measured engine speed.
2. Mapped engine models are suitable for analysis and design activities that do not require enigne subsystem dynamic characteristics, for example in engine and transmission powertrain matching analysis for fuel economy, emissions and performance trade-offs.
Dynamic Model:-
1.Dynamic engine decompose engine behavior into individual component models that account for engine dynamics,most notably intake airflow and turbocharger dynamics.
2.Dynamics engine models are suitable for desiging control,estimator and diagnostic,algorthims that depend on dynamic subsysytem states,for example in closed loop AFR(air fuel ratio)control algorithm development.
Switch model type,
1.Open the EV model in simulink.
2.Enter the passenger car block by double clicking it.
3. Go to electric plant block.
4. On motor block right click to find the variant option.
2. How does the model calculate miles per gallon? Which factors are considered to model fuel flow?
Ans, For Conventional vehicles, the fuel efficiency is calculated by miles per gallon(mpg). for Hybrid Electric Vehicles fuel efficiency is calculated by miles per gallon equivalent (mpge).
three parameter are taken into considerations:
1.vehicle speed.
2.fuel flow.
3.battery power.
The vehicle speed = 0.000621371.
similarly the kilogram of fuel is converted into cubic meter by multiplying by1/(1000*0.739)
this cubic meter value is then converted into gallons by multiplying it with 264.172.the mile value and gallon value is used to find mpg of the vehicle.
now the battery value is initially converted from watts to kwh by dividing with 1000 and then to gallon equivalent by again dividing it with 33.7(since 33.7 kwh=1 gallon)
then divide the value by 3600 to get in per seconds and multiply by 0.00378541 in to the value in cubic meter per gallons.
3. Run the HEV ReferenceApplication with WOT drive cycle. Change the grade and wind velocity in the environment block. Comment on the results.
The above block diagram for HEV ref application.
Here we have changed drive cycle to wot with a sample time of 35 seconds.
Drive cycle Description with mention 35 sec, fig shown in the above.
Environment block,
In the Environment block, As per the Question following modification has been down,
Grade Value - 10
Wind Velocity Value - 30 m/s
Visualization Block,
After the model completed, while seeing the output on the Performance and FE scope
PLOT,
From the above plot, Here we conclude,
plot 1:
trace velocity, target, actual
top velocity achieved - 40 mph.
time taken to accelerate - 30 sec.
time taken to deaccelerate - 2 sec
plot 2:
motor&engine rpm
top motor rpm= 5000rpm.
top engine rpm = 5000rpm.
plot 3:
motor& engine torque:
maximum motor torque = 175 N-m.
maximum engine torque = 60 N-m.
plot 4:
battery current:
max current in acceleration - 160 A
min current in deacceleration - -160 A
plot 5:
battery soc:
60 to 54 % - Deacceleration
54% - increasing acceleration
plot 6:
fuel economy:
maximum fuel Consumed = 6.
Above mention, conclusion is as oer the output data from the plot
4. Keeping all other parameters same, compare the simulated results of hybrid and pure electric powertrains.
By keeping all the data the same aper the data used in HEV Simulation, Below is the plot of what we get for the EV Simulation model,
Output Plot for HEV Block as above.
Output Plot for EV Train Block,
By comparing both HEV & EV,
1. Top speed is achieved by HEV than EV.
2. Battery current capacity of EV is higher as compared to HEV.
3. EV Consumed higher fuel economy.