Week-4 Challenge WOT Condition Part-2
TASK 1.
What is difference between mapped and dynamic model of engine , motor and generator ? how can you change model type.
SOLUTION:
Powertrain blockset provides two types of combustion engine models. mapped and dynamic.
MAPPED ENGINE:
Mapped engines represent macro engine behaviour as a set of lookup tables ( brake torque, fuel flow, air massflow,exahust temperature,efficiency and emissions) as functions of commanded load and measured engine speed.
Mapped engine mmodels are suitable for analysis and design activies that do not require engine subsystem dynamic characteristics , for example in engine and transmission powertrain matching analysis for fuel economy,emissions and performance trade offs.
DYNAMIC ENGINE:
Dynamic engine decompose engine behaviour into induvidual component models that account for engine dynamics,most notably intake airflow and turbo charger dynamics.
Dynamics engine models are suitable for desiging control,estimator and diagnodtic,algorthims that depends on dynamic subsystem states,for examples in closed loop AFR ( air fuel ratio ) control algorithm development.
we can switch b/w mapped and dynamic engines by following below procedures.
Open the ev model in simulink.
Enter the passenger car block by double clicking it.
Then go to electric plant block.
inside the motor block right click to find variation option. this option r available name of engine to click and change.
TASK 2.
How does thr model calculate miles per gallon?which factors are considered to model fuel flow?
SOLUTION;
for a conventional gasoline vehicle,the fuel efficiency is calculated via miles per gallon (MPG). fuel efficiencyfor hybrid models is calculated miles per gallon equivalent(MPGe). MPG is the number of miles your car can drive per gallon of gas. figuring out an MPGe rating is a little more complicated.since engines that use an altrnative source of fuel can't be measured by liquid gallons of fuel,the MPGe rating is calculated by figuring out the number of miles a vehicle can go using the same energy content as agallon of gas.the EPA calculates that 33.7 kilowatt hours of electricity is the equivalent to one gallon of gas.
in case of our EV model, inside the visualization block we have another block named performance calculations.
if we get inside this block we find the actual (MOG) calculations.
Three different inputs are taken into consideratin:
1.Vehicle speed
2.Fuel flow
3.Battery power
The vehicle speed input 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 by 1/(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 diving it with 33.7(since 33.7kwh=1 gallon).
then divide the value by 3600 to get in per seconds and multply by 0.00378541 to get the value in cubic meter per gallons.
TASK 3.
Run the HEV reference application with WOT drive cycle. change the grade and wind velocity in the environment block.comment on the results.
SOLUTION:
A HYBRID ELECTRIC VEHICLE (HEV) is a type of hybrid vehicle that combines a conventional internal combustion engine (ICE) system with an electric propulsion system.
the hybrid electric vehicle reference application represents a full multimode hybrid electric vehicle (HEV) model with an internal combustion engine,transmission , battery,motor,generator and asociated powertrain control algorithms.
The hybrid electric vehicle model is selected with the wide open throttle (WOT) drive cycle and we run the simulation in the matlab with the given input to the drive cycle.
the simulation result of HEV engine with WOT drive cycle with the given input in the drive cycle. there are total
different plot with differenant engine parameter.
the x-axis show the time of 100 sec and the y-axis show the value of the different parameter.
Now wind and grade value is changed in the environment block of the powertrain blockset
the simulation result in this condition is different from the previous condition where the grade and the wind velocity is not considered.
OBSERVATION FROM BOTH THE SIMULATION RESLUT
1.The top velocity in the 2nd simulation condition is not achieved but in the 1st simulation condition the top speed is more than the target top speed.
2.The fuel economy in the 2nd simultion is half of the 1st simulation result.the engine speed is also reduced in the 2nd conditon.
3.The rest of the parameter is same in both the simulation result.
TASK 4.
Keeping all other parameters same,compare the simulated results of hybrid and pure electric powertrain.
SOLUTION:
Pure electric vehicle
An electric vehicle is that uses one or more electric motors or traction motors for propulsion.keeping the all the same as in the HEV with all this parameter,run the simulation and result obtained are plot .
for the condition 2 with grade and wind velocity.
if we compard the both simulation result of the EV vehicle we should get the variation in the variation in the top speed,engine speed and the fuel efficiency of the engine.the top speed,engine and the fuel efficiency is reduced compare with the 1st condition simulation result.
COMPARE BETWEEN THE HEV AND EV:
1.The fuel efficiency of the ev is too much high than the HEV vehicle.
2.The discharging rate in the EV is lower compared to the HEV and the battery SOC is also higher in the EV.
3.The EV produced zero emission with respect to the HEV vehicle
4.The HEV vehicle come with IC engine,motor and generator due to which its weight is more for power produsing.