Week-4 Challenge WOT Condition Part-2

FOR QUESTION1:

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

MAPPED MODELS:

Mapped model are used when the behavior of a particular model is not of our intrest and it can be modeled with a predefined values in the form of lookup table

MAPPED ENGINE

1.It can be represent by macro engine behaviour as a set of lookupntables.(brake,torque,fuel,floe,air,nasflow,exhaust temperature,efficiency,and emissison) as function of commanded load measured engine speed.

2.this type of models are suitable for analysis and design activities that do not require engine subsystem dyanamic characteristics for example in engine and transmission powertrain matching analysis for fuel economy ,emissions and perforamnce trade-offs.

DYANAMIC ENGINE

1.This engines are decompose engine behavior into individual component model that account for engine dyanamic ,most notably imtake airflow and turbo charger dynamics.

2.this type of models are suitable for designing the control,estimator and diagnostics,alogorothms that depends on dyanamic subsystems states,for example in closed loop air fuel ratio control algorithm development

Here we can switch between mapped and dyanamic engines by following the below procedure:-

• open the ev model simulink by serching
• enter the passenger car block then by double click the block
• then go to the power plant
• inside that block of motor block right click to find the varian opetin then go to open next click on label modelactive choice then next it gives the two options we need to select the motGenEvDynamic option.

EV REFERANCE MODEL:

FOR QUESTION2:

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

• Miles per gallon(mpg)
• Miles per gallen equivalent(mpge)

For a conventional gasoline vehicle the fiuel efficiency is calculated by miles per gallon(mpg). then the fuel efficiency for hybrid electric vehicle is calculated by miles per gallen equivalent(mpeg)

We should go inside the EV referance block that is perforamance calculation:

Inside this block we will get the actual mpg calculations:

Here we have three different inputs are taken into the cinsiderations:

1.vehicle speed.

2.fuel flow

3.battery power

The vehicle speed inputs are in m/s which is converted into the miles by multiplying with 0.000621371

similarly, the kilogram of fuel is converted into the cubic meter so by multiplying by 1/(1000*0.739)

this cubic meter values is then converted into gallons by multiplying with the 264.172. the mile value and gallon value is used to find the mpg of the vehicle.

now the battery value is intially 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=1gallon)

then divide the value by 3600 to get in per seconds and multiply by 0.0037854 into get the value in cubic meter per galon

FOR QUESTION3:

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

Here we have the changed drive to WOT with a sample time 40 secomds

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

Environment Block:

RESULTS:

CONCLUSION:

PLOT1:

trace,velocity,target,actual:

top velocity can be achieved=50.1 mph

time taken to accelerate=29.034 sec

time taken to acceterTE=2.471 sec

PLOT2:

motor&engine rpm

top motor rpm=5712 rpm

top engine rpm=5451 rpm

PLOT3:

motor&engine torque

maximum motor torque=306.0 N-m

maximum engine torque=174.7 N-m

PLOT4:Battery current

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

PLOT5:Battery sco

the battery soc will falls from 80 to 65% during acceleration of vehicle and it increases slighylt 65 to 70% during the deccelaration due to negative braking

PLOT6:Fuel economy

maximum fuel economy achieved =4.675

FOR QUESTION4:

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

Simulated results of HEV:

Simulated results of EV:

CONCLUSION:

1.The top speed is achieved by HEV is more than the that of EV

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

3.Higher fuel economy is achieved in case of the pure EV