Week-4 Challenge WOT Condition Part-2

Q.1

What is the difference between the mapped and dynamic engine, motor, and generator models? How can you change the model type?

ans:-

powertrain backset provides two types of combustion engine models: mapped and dynamic.

Mapped engine:

1 Mapped engine represents macro engine behavior as a set of lookup tables(brake torque, fule air mass flow, exhaust temperature, efficiency, and emission ) as a function of commanded load and measured engine speed

2. Mapped engine models is suitable for analysis and design activities that do not require engine subsystem dynamic characteristic, for example in engine and transmission powertrain matching analysis for fuel economy, emissions, and performance trade-offs

Dynamic engine:-

1. Dynamic engine decomposes engine behavior into individual component models that account for engine dynamics, most notably, intake airflow and turbocharger dynamics.

2. Dynamic engine models are suitable for designing control, estimator, and diagnostic, an algorithm that depends on dynamic, subsystem states, for example in close loop AFR(air-fuel ratio).

_following the below procedures for mapped and dynamic engine

1. open the EV model in Simulink

2. enter the passenger car block by double click it.

3. then go to the electric plant block.

4. inside the motor block right-click to find the variant

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Q

2. How does the model calculate miles per gallon? Which factors are considered to model fuel flow?

Ans:

miles per gallon(mpg)& miles per gallon equivalent(mpge).

for a conventional gasoline vehicle, the fuel efficiency is calculated i=via miles per gallon (mpg). however fuel efficiency for hybrid electric vehicles is calculated via miles per gallon equivalent (page).mgp is the number of miles your car can drive per gallon of gas.

Several miles a can go using the same energy content as a gallon of gas. the EPA calculated that 33.7kwh of electricity is equal to one gallon of gas

We should go inside ev reference block that is performance calculations:

inside this block will get the actual mpg calculation:-

Here, their different inputs are taken into consideration:-

1. vehicle speed

2. fiel flow

3. battery power

The vehicle speed input is m/s which is converted into miles by multiplying by 0.000621317.

similarly, the kg of fuel is converted into a cubic meter by multiplying by 1/(1000*0.739).

this cubic meter value is converted into gallons by multiplying by 264.172, mile value and gallon value are used to find the mpg of the value/

Now,

the battery value is initially converted from wait to kWh by dividing by 1000 and then to gallon equal by an again dividing with 33.7 (since 33.7 kwh=1 gallons)

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Q3.Run the HEV ReferenceApplication with WOT drive cycle. Change the grade and wind velocity in the environment block. Comment on the results.

we have also altered the environment block and changed the wind speed to 25 m/s & grade to 10.

input value:-

Result:-

Conclusion:

Plot 1: trade velocity ,target ,actual:

top velocity achieved =50.1 mph

time taken to accelerate=29.034 sec

time taken to deaccelerate=2.471 sec

plot2: motor & engine rpm:

top motor rpm =5712 rpm

top engine rpm=5451 rpm

plot 3: motor & engine torque:

maximum motor torque =306.6 N-m

maximum engine torque =174.7 N-m

plot 4: Battery current

the battery supply current is at its maximum value of 167 Amp, when full throttle is applied by the user it reduces drastically to the value of negative 150 during acceleration of the vehicle.

plot 5: Battery soc

The battery soc will fall from 80 to 65% during acceleration of the vehicle and it increases slightly to 65 to 70% during de-acceleration due to regeneration braking.

plot 6:fuel economy

maximum fuel economy achieved= 4.675

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Q4.

Keeping all other parameters the same, compare the simulated results of hybrid and pure electric powertrains.

Ans:

A) simulation result of HEV.

B) simulation results of EV.

Conclusion

1. the top speed is achieved by hybrid electrical vehicles more than that of an EV

2. the battery current capacity of pure EV is much higher compared to that of HEV since an EV battery is only the driving unit.

3. HIhger fuel economy is achieved in case of pure EV