Week-4 Challenge WOT Condition Part-2
Ans1)
Mapped and Dynamic Subsystem of electric motor/generator:-
Mapped Model:-
The mapped model is one type where the data points are pre_assigned in lookup tables.
The engine or motor torque required is sensed and the motor or engine block. generates the requiered torque output just as required simply without considering the real time motor or engine, parameters.
The output values are stored for the corrresponding given input values of the engine motor and generator.The accuracy of this type is not that high but the simulation will be done in much less time as it does not run by real time parameters.
Dyanamic Model:-
The dyanamic model in other hand uses the combination of the outputs from various subsystems to generate the output.
It runs by real time simulation where the required input from the drive cycle is taken. and for that individiual real time simulation gets performed and summing all the results of the subsystem gives the output for the simulation.
As per the drive cycle requirements the initial Bus voltage current is given along with the vehicle feedback so that it runs the actual simulation at that particuclar moment throught the drive cycle.
The accuracy of this model is very high as it considers the real outputs from all the subsystem to generate the output. The simulation will take very long time to complete as it has so many individual simulations running by all the subsystem of the engine, motor/generator.
Steps to select the model type:-
As the given below screenshot shown generator of a hybrid electric vehicle.
While we double click on generator new screen will available as shown in below.
With an option to select between the map generator and dynamic generator.Now, the mapped generator is configured,if want to changed to the dynamic generator then need to follow the step.
Select the model which you want to configure --> click on variant manager --> click on label model active choice --> change the model.
Ans2).
The model calculation of miles per Gallon:-
Then the inputs from the vehicle speed (i.e) the Distance we found (in meters) is taken into the calculation and it is converted to the miles by multiplying with 0.000621371.
Then the inputs from fuel flow (Battery energy + Fuel energy) taken in mA3 and is converted into equivalent US Gallons by multiplying with 264.172.
Then the two inputs Miles covered and equivalent US Gallon is further divided and the result is got in Miles/ Gallon.
Miles per Gallon:-
Miles per Gallon is a fuel economy rating determined by how far a car can travel on a gallon of petrol or Diesel for a Engine powered car.
In case of an electric vehicle it tells us the energy which is equivalent that of a engine powered carto propel the car through a distance.
The amount of Fuel Energy required to move a engine powered car through a distance is determined and then it is compared to the eqivalent amount of electric energy required to move the car throgh the same distance and is expressed as the miles per gallon.
The powertrain blockset has a model that calculates the miles per gallon for all kinds of vehicle.
The factor consider for indicating the fuel efficiency are as mentioned below:-
- Vehicle Speed
- Battery Power
- Fuel Flow
Ans3)
Hybrid Electric Vehicle:-
1) Change the drive cycle to wide open throttle:
The simulation is done for Hybrid electric vehicle with Wide open Throttle Drive cycle.
The Total cycle time = 100 seconds
The Top speed of this cycle = 60 mph
Time to start deceleration = 30seconds
The Grade angle = 0 degrees
The wind velocity = 0 m/s
The above figure shows the results for the simulation and there are totally six plots in them.
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 135 mph but he actual velocity achieved was near to 100 mph.
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.
Plot 3 (Engine Torque, Motor Torque and Generator Torque) Nm - This plot gives the detailed analysis of the Engine, Motor Torque and Generator Torque.
Plot 4 (Battery Current) A - This plot denotes the power produced by the Battery and the readings are in Ampere.
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.
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.
2) Change the drive cycle to wide open throttle:
The simulation is done for Hybrid electric vehicle with Wide open Throttle Drive cycle.
The Total cycle time = 100 seconds
The Top speed of this cycle = 60 mph
Time to start deceleration = 30seconds
The Grade angle = 5 degrees
The wind velocity = 10 m/s
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 135 mph but he actual velocity achieved was near to 75 mph.
Observation:
The simulation results for both the cases is found and we can see that the simulation 1 without the inclusion of hill climbing conditions and the wind drag velocity is much more efficient when compared to the simulation which includes the hill climbing conditions and the wind drag velocity.
The vehicle was not able to achieve the required top speed though using the highest possible current discharge of that same battery used before.
The state of charge also shows that the discharge is also high compared to the simulation 1
The Fuel Economy is also down to half of the previous simulation.
So one can say, it is evident that the efficiency of no load vehicle is high compared to the vehicle with additional loads acting on them and also we have visualized this using the Powertrain blockset.
Ans.4)
Pure Electric Vehicle:-
Pure Electic Vehicles (also know as battery electric vehicles) run off one power source only - the electric battery. There is no combustion engine present which means they are the cleanest option and never produce tailpipe emissions and hence the most sustainable.
1) Change the drive cycle to wide open throttle:
The simulation is done for Pure electric vehicle with Wide open Throttle Drive cycle.
The Total cycle time = 100 seconds
The Top speed of this cycle = 60 mph
Time to start deceleration = 30seconds
The Grade angle = 0 degrees
The wind velocity = 0 m/s
plot 1:
Shows the velocity of the vehicle with respect to the Drive cycle data with the Time scale on the x axis.
The top speed of 60 mph cannot be achieved as we have some additional forces acting and so the car can only run upto 95mph The acceleration time to reach top speed of
95 mph = 30.2 seconds
The deceleration time from 80 to minimum = 9.7 seconds
plot 2:
Shows the changes in speed of the Motor in Rpm throughout the drive cycle.
Peak Motor speed = 9924 Rpm
plot 3:
Shows the Torque characteristics and its
changes of Motor in (Nm) throughout the
drive cycle.
Peak Motor torque = 280 Nm
plot 4:
Shows the Battery Current values (A) and its changes for various acceleration inputs as per the Drive cycle.
The peak current discharge from the battery = 223 A
The peak current charging to the battery = -153.1 A
Plot 5:
Shows the Battery state of charge SOC (%) and its changes corresponding to the driving inputs.
The state of charge decreased from 80% to 77.3% of charge in a time period of 30.3 seconds, for the specified driving conditions.
Plot 6:
Shows the Equivalent Fuel Economy as Mile per Gallons for the corresponding input driving conditions. Here there is no fuel in pure electric vehicle however this gives equivalent battery energy required that of the fuel energy,and calculates the Fuel efficiency.
2) Change the drive cycle to wide open throttle:
The simulation is done for Pure electric vehicle with Wide open Throttle Drive cycle.
The Total cycle time = 100 seconds
The Top speed of this cycle = 60 mph
Time to start deceleration = 30seconds
The Grade angle = 5 degrees
The wind velocity = 10 m/s
plot 1:
Shows the velocity of the vehicle with respect to the Drive cycle data with the Time scale on the x axis.
The top speed of 60 mph cannot be achieved as we have some additional forces acting and so the car can only run upto 66.9mph
The acceleration time to reach top speed of
66.9 mph = 30.2 seconds
The deceleration time from 80 to minimum = 5.6 seconds
plot 2:
Shows the changes in speed of the Motor in Rpm throughout the drive cycle. Peak Motor speed = 7066 Rpm
plot 3:
Shows the Torque characteristics and its changes of Motor in (Nm) throughout the
drive cycle.
Peak Motor torque = 280 Nm
plot 4:
Shows the Battery Current values (A) and its changes for various acceleration inputs as per the Drive cycle.
The peak current discharge from the battery = 224.75 A
The peak current charging to the battery = -153 A
Plot 5:
Shows the Battery state of charge SOC (%)
and its changes corresponding to the driving inputs. The state of charge decreased from 80% to 77.34% of charge in a time period of 30 seconds, for the specified driving conditions.
Plot 6:
Shows the Equivalent Fuel Economy as Mile per Gallons for the corresponding input driving conditions. Here there is no fuel in pure electric vehicle however this gives equivalent battery energy required that of the fuel energy,and calculates the Fuel efficiency.
Comparison (Pure Electric VS Hybrid Electric Vehicle With Same Load Conditions):-
1. The electric vehicle when compared with hybrid electric vehicle with the same environmental and Drive cycle conditions results in less top speed achievement. The electric vehicle produces more values of Motor speed and motor torque compared to the hybrid vehicle's motor alone, but hybrid. vehicle when it combines the torque of both motor and its engine it is higher than the electric vehicle's torque. This is responsible to pull the Hybrid car at higher top speed compared to the pure electric.
2. As the pure electric car here uses Lithium ion battery compared to the Nickel metal hydride battery the discharging capacity and the rate of charging is higher in the pure electric car. As it is able to discharge in a fast rate the motor can produce high amount of torque instantly compared to the hybrid vehicle. Also the state of charge shows the battery efficiency of the pure electric to be higher than the hybrid vehicle and this is also due to the battery type used in these cars.
3. The efficiency of the Electric car is higher than the hybrid car which is evident from the miles per gallon numbers of both of these cars.
4. Electric vehicle produces zero emissions whereas the hybrid one's produce waste gas. emission.
These are some of the observations from the comparision of the above simulations using Powertrain Blockset.