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?

                                 Figure 1

Figure 1 shows the mapped and dynamic model of motor and generator

Mapped model 

1) In mapped model data points are pre-assigned in lookup table which would be configured with the operational parts and the analysis would be formed.

2) Model uses a set of steady-state lookup tables to characterize engine performance.

2) Output values are stored for the given corresponding input values of the motor, generator and engine

3) The accuracy is low for this system.

4) Run time simulation takes less time, because it dose not run with real time simulation.

                                                Figure 2

Figure 2 shows the mapped model

Dynamic model

1) Dynamic model runs by real time simulator.

2) Dynamic model uses the combination of output from various subsystems to generate output.

3) The accuracy of dynamic model is very high.

4) Run time simulation takes more time.

                                                 Figure 3

Figure 3 shows the dynamic model

Steps to change model

1)  Select vehicle type in powertrain blockset model.

2)  Go to the passenger block in the simulink model of Electrical Vehicle motor/Generator.

3)  Right click on block and go to variance label mode active choice MotorGenEV Mapped or Dynamic.

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

In electrical vehicle miles per gallon tells thatenergy which is equivalent that of a engine powered carto propel the car through a distance

                                               Figure 4

Figure 4 shows the performance calculations of fuel flow

Miled per gallon expressed as the amount of fuel energy required to move a engine powered car through a distance is determined and the it is compared to the equivalent amount of electric energy required to move the car through the same distance.

it has

1) Vehicle speed

2) Battery power

3) Fuel flow

                                                      Figure 5

Figure 5 shows the powertrain blockset that takes input of the vehicle speed

Conversion from Cubic meter to gallon

1000 liters = 264.17 US gallons

The output is calculated depending on Fuel and battery output and also vehicle speed

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

 HEV is the vehicle which runs with the combination of engine and battery

                                                          Figure 6

Figure 6 shows the series-prallel connection of HEV

                                                       Figure 7

Figure 7 shows 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

                                                        Figure 7

Figure 7 shows the input values

                                                     Figure 8 

Figure 8 shows 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

                                                Figure 9

Figure 9 shows the input values 

                                                       Figure 10

Figure 10 shows the results with above specifications

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

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

                                                  Figure 11

Figure 11 shows the block diagram of pure Electrical vehicle

                                                 Figure 12

Figure 12 shows the results of pure Electrical Vehicle

                                                  Figure 13

Figure 13 shows the block diagram of HEV 

                                                Figure 14

Figure 14 shows the results for HEV

The difference between EV and HEV is for EV the source is only one i.e. electric source, 

where as for HEV thre are two sources one is fuel and next one is electrical. For the both EV and HEV the results will differ according to figure 12 and 14