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: Uses pre-defined lookup tables or data maps (e.g., torque, efficiency, or fuel consumption) for simulation.

• Advantages:
  • Faster simulation time.
  • Suitable for high-level analysis and early design phases.
  • Less computationally intensive.
• Limitations:
  • Less accurate for transient or real-time behavior.
  • Does not consider physical dynamics or component interactions.

Dynamic Model: Simulates the physical behavior of the engine, motor, or generator using first-principle equations and dynamic relationships.

• Advantages:
  • More accurate for transient analysis and detailed studies.
  • Captures real-time dynamic behavior and interactions.
• Limitations:
  • Requires detailed component specifications and parameters.
  • Computationally intensive and slower simulation.

Changing Model Type:

1. Engine, Motor, or Generator Block Settings:

   • Open the block properties for the specific component.
   • Locate the Model Type option.
   • Select either Mapped Model or Dynamic Model from the dropdown menu.

2. Changing Through Parameters:

   • Some models allow switching by setting a specific parameter (e.g., ModelType = 'Mapped' or ModelType = 'Dynamic').

3. Replacing the Block:

   • Replace the mapped model block with a dynamic model block from the Simulink library, if required.

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

Miles per gallon (MPG) is a measure of fuel efficiency calculated as

$$\text{MPG} = \frac{\text{Total Distance Traveled (miles)}}{\text{Total Fuel Consumed (gallons)}}$$

1. Total Distance Traveled:

   • Determined from the vehicle speed profile and the simulation duration.
   • Integrated over time to calculate the total distance covered.

2. Total Fuel Consumed:

   • Calculated from the fuel flow rate (mass or volume) output by the engine model.
   • Fuel flow rate is integrated over time to get total fuel consumed in gallons.

3. Conversion to Gallons:

• Fuel consumption is often modeled in mass (e.g., kilograms or grams).
• Conversion is done based on fuel density (e.g., gasoline density ≈ 0.74 kg/L or 6.17 lbs/gallon).

FACTORS CONSIDERED

1. Engine Performance Maps:

   • Fuel flow is derived from lookup tables or dynamic models of the engine, correlating fuel consumption with engine speed and torque.

2. Vehicle Operating Conditions:

   • Speed and Acceleration: Higher speeds and rapid accelerations lead to increased fuel consumption.
   • Load: Vehicle weight and additional loads increase fuel demand.

3. Engine Efficiency:

   • Varies with operating conditions (e.g., speed, torque, and throttle position).
   • Includes losses due to friction, heat, and suboptimal combustion.

4. Transmission Efficiency:

   • Losses in the drivetrain due to gear changes and friction.

5. Aerodynamic Drag and Rolling Resistance:

   • Fuel flow increases with resistance from air drag and tires.
   • Proportional to vehicle speed and road conditions.

6. Ambient Conditions:

   • External temperature and pressure affect fuel combustion efficiency.

7. Accessories Power Demand:

   • Additional power required for auxiliary components (e.g., air conditioning, lights) impacts fuel consumption.

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

the series-prallel connection of HEV

the simulink model of Hybrid Electrical Vehicle

Case 1

below are the input parameters of drive cycle source

100 seconds of total cycle time

speed = 80 mph

gread angle 0

wind velocity 0 m/s

the input values

the output, based on the input parameters of drive cycle source

Observations

Plot 1:-

Around 16.5 seconds of time will take to reach maximum speed (80 mph)

Nearly 6.1 seconds of time will take to reach maximum speed (80 mph) to 0 mph

Plot 2:-

Plot 2 shows the speed

maximum speed of motor = 9497 rpm

Plot 3:-

plot 3 shows the torque

maximum motor torque = 206 Nm

Plot 4:-

plot 4 shows the current values of battery varies from 500 to 0 amps in normal mode and

varies from 0 to -200 amps in regenerative braking

Plot 5:-

plot 5 shows the battery SOC

SOC decreased form 80 to 62 % increased during normal condition and

from 62 to 76 % during regenerative braking

Plot 6:-

plot 6 shows the fuel economy

maximum fuel economy is 20.45 MPG

minimum fuel economy is 7.18 MPG

Case 2

Cycle time 100 sec

speed 80 mph

gread angle 5

wind velocity 5 m/s

Plot 1:-

Maximum 59 mph reached in 49 seconds

maximum to minimum speed reached in 4.6 seconds

plot 2:-

maximum motor speed is 6254 rpm

plot 3:-

maximum motor torque is 280 Nm

plot 4:-

battery SOC for 80 to 75 % in 50 seconds

plot 5:-

battery current remains constant of 200 amps

plot 6:-

maximum fuel economy is 21 MPG

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

PURE ELECTRIC VEHICLE :

OUTPUT :

HYBRID ELECTRIC VEHICLE :

OUTPUT: