Week-4 Challenge WOT Condition Part-2
1.What is the difference between mapped and dynamic model of engine, motor and generator? How can you change model type?
Mapped Engine:it is a default setting in powertrain blockset.it shows the lookup tables of engine .these tables shows based on the values of brake torque, fuel flow,air mass flow,exhaust temperature,efficiency and emissions.these datas used for end users lookup the various parameters of an engine and to find other parameters.these parameters helps to measure various performance parameters of vehicle.
Dynamic Engine:Default setting in powertrain blockset it shows the real time values and datas fed to the end users for performance and parameters analysis and calculations.this model is more accurate than the mapped engine. because of real time data.we can calculate brake torque fuel flow, exhaust temperature ,exhaust mass flow rate.
Mapped motor:mapped motor works in torque control mode.when needs a faster simulation mapped motor is used.output torque and reference torque is comparede and after that output changes are made.input torque,electrical losses , efficiency can be measured.
Dynamic motor:in dynamic motor 3 phase permanent magnet synchronous motor is used.the block uses the 3 phase voltages to regulate the phase currentsthis motor is more accurate.
mapped generator:mapped generator is another block in powertrain blockset.the datas required is taken from other input parameters.
Dynamic generator:user can enter the input parameter during the run time for their particular applications.
Changing the model type
in hev reference simulink file click on car passenger>>electric plant>>motor>> right click on motor shows variant icon which use to change the model type whether it is dynamic or mapped in this case
How does the model calculate miles per gallon? Which factors are considered to model fuel flow?
MPG, or miles per gallon, is the distance, measured in miles, that a car can travel per gallon of fuel. MPG is also the primary measurement of a car's fuel efficiency: The higher a car's MPG, the more fuel efficient it is.
in the case of ev reference application
check into performance calculations on the outside visualisation file
Here for calculations 3 inputs are taken
speed of the vehicle
Battery power
fuel flow
The vehicle speed inputs is in m/s which is converted into miles by multiplying with 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(sincw 33.7 kwh=1 gallon) then divide the value by 3600 to get in per seconds and multiply by 0.00378541nto get the value in cubic meter per gallons.
Run the HEV ReferenceApplication with WOT drive cycle. Change the grade and wind velocity in the environment block. Comment on the results.
in hev reference application we have changed the drive cycle to wot drive cycle
Here in block parameters of wot drive cycle sample time is kept to 30 sec
in the environment block grade is changed to 10 and the wind velocity to 20
Output
Top velocity achieved =30.1mph
Time taken to accelerate=20.2
time taken to deccelerate=1.6
Keeping all other parameters same, compare the simulated results of hybrid and pure electric powertrains.
Conclusions
- hybrid electric vehicle has more speed than ev vehicle
- Battery current capacity is high in ev than hev
- higher fuel economy is achieved in ev