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 model	Dynamic model
   Engine	It is used to measure to measure performance parameters of the vehicle by using standard lookup tables which are prefed to the system. This type of modelling is less accurate. If any other parameter like Input engine temperature is selected then lookup table values are also a function of the temperature parameter. These data are taken before reaching the user.	This type of model uses real time data fed by the user at run time for modelling. This model is more accurate than mapped engine model. The subsystems are used in this to get more accurate data. The input data are fully desired by the developer.
   Motor	This works in torque control operation. This type is used when the user requires a faster simulation and doesn't have the knowledge of motor parameters. The output torque and reference torque is compared and changes are made. Input torque or speed can be specified, electrical losses and maximum motor power and torque can be defined.	Here they use three phase interior permanent magnet synchronous motor (PMSM) is used. The block uses three phase input voltages to regulate the individual phase currents, allowing control of the motor torque or speed. This block is used when the user knows what parameters are to be used in that particular simulation. This motor is more accurate.
   Generator	Here also the data required is taken from the lookup tables corresponding to the given input parameters. Its simulation time is less. This is used by a person who has lesser knowledge in generator.	The dynamic generator involves user entering the parameters manually during the run time for their particular applications. The results take time and are more accurate.

We can change the model type by the below procedure-

Open the ev model and get into passenger car subsystem and right click on MotGenEvDynamic block , goto variant => open => choose MotGenEvmapped or MotEvDynamic as per your need.

Hence by this we can change the model type.

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

Miles per gallon for electric vehicles (MPGe, or “miles per gallon equivalent”) places a value on your car’s energy efficiency. A higher MPGe indicates a higher energy efficiency rating; a lower MPGe indicates a lower rating. MPGe is independent of factors such as range and battery life, so it remains important to examine your vehicle’s fuel efficiency.A higher efficiency rating will mean lower electricity costs per mile. Of the above vehicles, the Chevy Bolt boasts the highest efficiency rating. The Tesla Model X has the lowest efficiency of the list, with a rating that is 17 MPGe lower than the Bolt. This means that, completely separate from range, horsepower, or any other metric of comparison, you would end up paying less per mile to drive a car like the Bolt than a car like the Model Xb.

Here we are using performance calculation block to calculate the MPG.

The vehicle speed and battery power is taken in consideration to calculate the MPG. Then we are converting the battery power to galon and then equating vehcile speed and battery power in galon to MPG.

The Battery power and vehcile speed are the factors considered to model the fuel flow.

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

We have open the HEV ReferenceApplication and in that open the WOT block or else use comman window to open the HEV ReferenceApplication.

Now Double click on WOT choose the drive cycle source to WOT and click apply and see the results.

Now go to environment block and change the values of grade and wind.

Here i have kept garde as 6 and wind value as 10.

Thus we can see that the MPG increases when the vehicle travels continously for a long time at constant speed, after a certain period the velocity is reduced, so the torque and other parameters is also reduced and the Mpg increases.

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

Now open the ev model and change the WOT, grade, and wind parameters to same as HEV and Run it.

The values are changed as same in HEV.

The below both the graph shows the difference between the performance of HEV and EV.

HEV output-

EV output-

Result-

Hence we can see that except the MPG all other performance are nearly same. The MPG is better in EV than the HEV because EV is purely depend upon electric which will reduce the fuel usage and increase the efficiency.