Difference Between Mapped and Dynamic Models Engine, Motor and Generator

Question - 1

What is the difference between mapped and dynamic model of engine, motor and generator? How can you change model type?

Difference between Mapped and Dynamic models

Engine, Motor and Generator

Example of Changing Model Type

As per the screenshot appended below of the Generator of a Hybrid Electric Vehicle.

While we enter in the Generator new screen with the below mentioned screen is available

With an Option to select between the Mapped Generator and the Dynamic Generator. Currently the Mapped Generator is configured, if we wish to change this to the Dynamic Generator then we just need to follow the steps

Select the Model which you want to configure -> Choose Variant Manager -> Right Click the Model you wish to choose and then Set as Label Mode Active Choice.

Question - 2

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

The Factors considered for indicating the Fuel Efficiency are as mentioned below,

i) Vehicle Speed

ii) Battery Power

iii) Fuel Flow

The Conversion to Miles Per Gallon and the Fuel Flow is as mentioned with the steps below-

Conversion from Cubic Meter to gallon (m^3 to gallon),

As we know 264.172 US Gallons is 1000L

The reference model taken here for consideration is HEV and as it operates on both the Battery and the Fuel Injection Engine.

The final output/Fuel Efficiency is calculated by keeping in consideration of the Battery Output, Fuel Output and the Vehicle Speed/Kilometres Driven. Therefore the fuel efficiency is calculated and it is converted after the saturation thus the FE is calculated.

Question - 3

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

HEV - WOT Drive Cycle (Data Input)

The cycle was carried out for 60 seconds.

Performance Scope - WOT Cycle

Observations

1. Plot 1 (Trace Velocity Target vs Actual) - Through this plot it is denoted that the desired Velocity has not been met by the actual vehicle velocity. The desiered velocity was ranging at near about 140 mph but he actual velocity achieved was near to 110 mph.
2. Plot 2 (Engine Speed, Motor Speed) rpm - This plot gives the detailed analysis for the achieved Engine and Motor speed in rpm. The contribution of both the Power Generating sources for meeting the required Velocity.
3. Plot 3 (Engine Torque, Motor Torque and Generator Torque) Nm - This plot gives the detailed analysis of the Engine, Motor Torque and Generator Torque.
4. Plot 4 (Battery Current) A - This plot denotes the power produced by the Battery and the readings are in Ampere.
   
   
5. Plot 5 (Battery SOC) - This plot denotes the State Of Charge of the battery, this denotes the range of charge used for the achievement of velocity.
6. Plot 6 (US Fuel Economy) MPGe - This is the Fuel Efficiency or the Range of the drive and the same is denoted in Miles Per Gallon equivalent.

WOT Cycle with changes in Grade and Wind Velocity

The variables input for the change in these aspects are as given below,

The observations from the results as compared to the normal situations are mentioned below,

Comments/Comparison of the results obtained.

1. Plot 1 (Trace Velocity Target vs Actual) - This is clearly visible that as the grade and the wind velocity is increased compared to the normal state the vehicle is not able to reach the target velocity.
   
   
2. Plot 2 (Engine Speed, Motor Speed) rpm - In this plot comparing with the normal plot the Engine Speed has reduced to a steep slope on the negative side as compared to the normal situation the grade is increasing the load on the engine and thus the targeted Engine Speed is not met.
   
   
3. Plot 3 (Engine Torque, Motor Torque, Generator Torque) Nm - There are multiple variations in all these aspects and the same is visible in both the results of Normal and with the Grade and Wind Velocity.
   
   
4. Plot 4 (Battery Current) A - Battery current has been fluctuating at a higher range as compared to the normal after the vehicle is reaching near to the steady/stable pace the fluctuation starts and is simulated.
   
   
5. Plot 5 (Battery SOC) - The Battery State of Charge remains more or less similar in both the cases and are resulted at 65% after the end of the WOT Cycle.
6. Plot 6 (US Fuel Economy) MPGe - The average fuel economy differ in the range of 6 and 9 mph in both the scenarios.

Question - 4

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

Below mentioned vehicle is simulated for the EV Reference

The Performance and FE Results obtained are appended as below,

Below mentioned vehicle is simulated for the HEV Reference

The Performance and FE Results obtained are appended as below,

Remarks -

The overall difference in both these simulations are their vehicle operations where the EV is completely operated on Battery as the Power Sorce and on the other hand the HEV has two power soures SI/CI Engine and Battery. The results obtained are varied and the parameters are also differenciated accordingly.