Week-4 Challenge WOT Condition Part-2
Question 1: What is the difference between mapped and dynamic model of engine, motor and generator? How can you change model type?
Solution: Mapped model: Model uses a set of steady state lookup tables to characterize performance or represents macro engine behaviors as a set to lookup tables. The tables provide overall engine characteristics, including actual torque, fuel flow rate, BSFC, and engine-out exhaust emission. Mapped engine model are suitable for analysis and design activities that do not required engine subsystem dynamic characteristics.
Dynamic Model: Engine decomposes engine behaviors into individual component models that account for engine dynamic, most notably intake airflow and turbo charger dynamics. Dynamic engine model uses are suitable for designing control, estimator and diagnostic algorithm that depends on dynamic subsystem.
We can switch b/w engine model type based on our application shown in yellow box:
Question 2: How does the model calculate miles per gallon? Which factors are considered to model fuel flow?
Solution 2: Miles per gallon is calculated as shown in fig below:
Factor:
- Velocity
- Battery power
- Fuel flow
Question 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 3: Without Change Result:
- With Change in Grade = 5 and wind velocity=20;
Conclusion: When we compare above simulation results we can see the change in vehicle velocity, SOC of battery and other parameters. Fig 1 & 2 are the simulation results when grade and wind parameter is kept 0. Fig 3 & 4 shows the simulation results when Grade is ‘5’ and Wind is ‘20’.
Question 4: Keeping all other parameters same, compare the simulated results of hybrid and pure electric powertrains.
Solution 4: Simulation results of Pure EV Powertrains with grade = 5 and wind = 20
Simulation result of HEV Powertrains with grade = 5 and wind = 20;
Conclusion: When the parameters for Pure EV and HEV kept same the simulation result shows no change in result.