Week-4 Challenge WOT Condition Part-2

Ans 1).

Mapped and dynamic subsystem of electric Motor/Generator

Mapped Model-

• The mapped model is one type where the data point are pre_assigned in lookup tables.
• The engine or motor torque required is sensed and the motor or engine block generates the required torque output just as required simply without considering the real time motor or engine , parameters.
• The output values are stored for the corresponding given input valus 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 the real time parameters.

Dynamic Model-

• The dyanamic model in other hand use the combination of the output from various subsysrems to generates the oitput.
• it runs by real time simulation where the rwuired input from the drive cycle is taken and for the individual real time simulation gets performed and summing all the result of the subsystem gives the output for the simulation.
• The drive cycle requirement of the initial bus voltage, current is given along with the vehicle feedback so that it runs the actual simuation at that particular moment throught the drive cycle.
• The accuracy of the model is very high as it considers the real output from all the subsystem to generate the output.
• The simulation will tae very long time to complete as it has so many individual simulation running bye all the subsystem of the engine, motor/generator.

Step to select the model type-

1. In the power train model first need to select the vehicle type first wheather it is full elecric , full engine or the hybrid vehicle.
2. After that the simulink model appears by showing the work floe blocks of the model.
3. In thta we need to go to passeneger block electric plant EV Motor/Generator block.
4. After this just right click and go to variance label mode active choice motorGenEV Mapped or Dyanamic.

Ans 2).

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 a fuel energy required to move a engine powered car through a distance is determined and then it is compared to the equivalent amount of electric energy required to move car through the same distance and is expressed as the miles per gallon.
• The powertrain blockset has a model that calculate the miles per gallom for all kinds of vehicle.

• The above model task the input of the vehicle speed, fuel flow and battery power to calculate the fuel consumption and the equivalent battery consumptionn and calculate the miles per gallon.

Vehicle Speed And Fuel Flow-

• The vehicle spped is a important factor while considering the fuel consumption at that particular time, so to determine the fuel consumption throughout the drive cycle.
• To convert speed to distance we can integrate with time and we are doing the same of converting the velocity to get distance covered by intergrating.
• Then the fuel floe is expressed as the mass flow rate that is thr amount of fuel at each moment in kg/sec. now integrating this will result in the mass of the fuel and by using this 1 we convert it to the volume and by multiply by 1000 to get it in litres.
• By comparing the two result we can get the amount of litre consumed to run for 100km.

Battery Power-

• The amount of energy from battery power required to propel the vehicle equivalent to that of the engine is calculated here.
• The battery power is given in watts and it is converted to kw by dividing with 1000.
• Then we convert the power into energy by multiplying with the time into kWh.
• Then we convert the energy from Kwh to equivalent energy in US gallon of automotive gasoline by divding with 33.7 since we get the energy in US gallon equal in kWh we are trying to get the energy of equivalent LIS Gallons per seconds and we do this by dividing with 3600 and we convert the hour to seconds.
• Then multiplying with 0.00378541 we convert the USv Gallon per drc tp the volume of the fuel flow in(mA3/s) and then we multiply with 739(california Phase II gasoline density)(i.e) mA/s*kg/mA3 which gives the result as mass flow rate kg's.
• Then finally the battery energy equivalent in kg/s is given as a input for the fuel flow parameters in order to find the equivalent US Gallons energy and estimate the Miles per gallons.

Calculating Miles Per Gallon-

• Then the input from the vehicle speed (i.e) the distance we found (in meters) is taken into the calculation and it converted to the miles by multiplying with 0.000621371
• Then the input 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 input miles covered and equivalent US Gallon is futher divided and the result is got in miles /Gallon.

Ans 3).

Hybrid Electric vehicle-

• A hybrid electric vehicle (HEV) is a type of hybrid that combines a conventional internal combustion engine (ICE) system with an electric propulsion system.
• The presence of the electric powertrain is intended to achieve either better fuel economy that a conventional vehicle or better performance.
• Eample of HEV is Toyota Prius.

• In the powertrain blockset we have selected the hybrid electric vehicle and this is the simulink model.
• Here we can select the input parameters as we wish and we can Run the simulation to check the result.

Case 1-

Simulation conditions-

The simulation is done for Hybrid electric vehicle with wide open throttle Drive cycle time=100 seconds

The top speed of thid cycle =80mph

Time to start deceleration=50 seconds

The Grade angle=0 degree

The wind velocit= 0 m/s

• The above figure shows the result for the simulation and there are totally six plot in them.
• Each plot shows a particular result and the plot are made in such a way that, there is a cursor measurement and if we change the cursor on one plot the cursor moves on the otherplot too which paves way to study the result in better way.
• The cursor enables us to study the behaviour of other result parameters corresponding to the accelaration of the vehicles.

Plot 1-

Show the velocity of the vehicle with respect to the drive cycle data with the Time scale on the x axis.

The acceleration time to reach 820mph-16.7 seconds.

The deceleration time form 80 to minimum=6.2 seconds.

Plot 2-

Shows the change in speed of the engine, motor and generator in RPM throughout the drive cycle.

Peak Engine speed =4780RPM

Peak motor speed =9497RPM

Peal Generator speed =13690RPM

Plot 3-

Shows the torque characteristics and its change of engine, motor and generator in (NM) throughout the drive cycle.

Peak Engine torque =138.7NM

Peak motor torque =206.7NM

Peal Generator torque =42.2NM

Plot 4-

Shows the battery current values (A) and its changes for various acceleration input as per the drive cycle.

The peak current discharge from the battery=163.5A

The peak current charging to the battery= -150.86A

Plot 5-

Show the battery state of charge SOC(%) and its changes corresponding to the driving inputs.

The state of charge decreased from 60% to 39.8% of charge in a time period of 49.3 seconds, for the specified driving conditions.

Plot 6-

Show the Fuel economy as Mile per Gallons for the corresponding input driving conditions.

The maximum miles that the car run per gallon of fuel equivalent= 46 miles, for the given vehicle at the spedified driving conditions.

• In all the result we can observe some change from the previous case
• Through the vehicle parameterw and the drive cycle are the same, here we have considered some changes in the environment blocks by adding some hill climbs angles and wind velocity.
• The changes in the result are given below.

Plot 1-

Show the velocity of the vehicle with respect to the drive cycle data with the Time scale on the x axis.

The top speed of 80mph cannot be achieved as we have some additional forces acting and so the car only run upto 67.2mph.

The acceleration time to reach top speeed of 67.2mph=44.5 seconds.

The deceleration time form 80 to minimum=5.06 seconds.

Plot 2-

Shows the change in speed of the engine, motor and generator in RPM throughout the drive cycle.

Peak Engine speed =4676RPM

Peak motor speed =8103.5RPM

Peal Generator speed =12858.5RPM

Plot 3-

Shows the torque characteristics and its change of engine, motor and generator in (NM) throughout the drive cycle.

Peak Engine torque =139.6NM

Peak motor torque =206.4NM

Peal Generator torque =48.2NM

Plot 4-

Shows the battery current values (A) and its changes for various acceleration input as per the drive cycle.

The peak current discharge from the battery=167.6A

The peak current charging to the battery= -152.46A

Plot 5-

Show the battery state of charge SOC(%) and its changes corresponding to the driving inputs.

The state of charge decreased from 60% to 25.98% of charge in a time period of 49.3 seconds, for the specified driving conditions.

Plot 6-

Show the Fuel economy as Mile per Gallons for the corresponding input driving conditions.

The maximum miles that the car run per gallon of fuel equivalent= 17.93 miles, for the given vehicle at the spedified driving conditions.

Observation-

• The simulation result 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 requiresd top speed through using the higest 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 aslo we have visualized this using the powertrain blockset.

Ans 4).

Pure Electric Vehicle-

• A Battery electric vehicle or pure electric vehicle is a EV that exclusively uses chemical energy stored in rechargable battery pack with no secondary source of proplusion of energy.
• BEVs use electric motors and motor controllers instead of an conventional internalk combustion engines for propulsion. They derive all power from battery packs.
• so they don't produce any emission of waste gas and they are eco friendly.
• They also have their own limitations such as range etc.
• Example of pure EV is Nissan Leaf.

• Now comparing both the Pure electric and Hybrid electric vehicle with the given conditions in a simulation to observe the behaviour of the both the type.

Case 1-

Simulation conditions-

The simulation is done for Pure electric and Hybrid electric vehicle with wide open throttle Drive cycle.

The total cycle time=100 seconds

The top speed of thid cycle =80mph

Time to start deceleration=50 seconds

The Grade angle=0 degree

The wind velocit= 0 m/s

Plot 1-

Show the velocity of the vehicle with respect to the drive cycle data with the Time scale on the x axis.

The top speed of 80mph cannot be achieved as we have some additional forces acting and so the car only run upto 108.9mph.

The acceleration time to reach top speeed of 108.9mph=50.2 seconds.

The deceleration time form 80 to minimum=9.8 seconds.

Plot 2-

Shows the change in speed of the motor in RPM throughout the drive cycle.

Peak motor speed =1123RPM

Plot 3-

Shows the torque characteristics and its change of motor in (NM) throughout the drive cycle.

Peak motor torque =260NM

Plot 4-

Shows the battery current values (A) and its changes for various acceleration input as per the drive cycle.

The peak current discharge from the battery=216.8A

The peak current charging to the battery= -173.7A

Plot 5-

Show the battery state of charge SOC(%) and its changes corresponding to the driving inputs.

The state of charge decreased from 80% to 75.5% of charge in a time period of 50.3 seconds, for the specified driving conditions.

Plot 6-

Show 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. The maximum miles that the car run per gallon of fuel equivalent= 20.45 miles, for the given vehicle at the spedified driving conditions.

Case 2-

Simulation conditions-

The simulation is done for Pure electric and Hybrid electric vehicle with wide open throttle Drive cycle.

The total cycle time=100 seconds

The top speed of thid cycle =80mph

Time to start deceleration=50 seconds

The Grade angle=8 degree

The wind velocit= 10 m/s

Plot 1-

Show the velocity of the vehicle with respect to the drive cycle data with the Time scale on the x axis.

The top speed of 80mph cannot be achieved as we have some additional forces acting and so the car only run upto 58.9mph.

The acceleration time to reach top speeed of 58.9mph=48.8seconds.

The deceleration time form 80 to minimum=4.63 seconds.

Plot 2-

Shows the change in speed of the motor in RPM throughout the drive cycle.

Peak motor speed =6254RPM

Plot 3-

Shows the torque characteristics and its change of motor in (NM) throughout the drive cycle.

Peak motor torque =280NM

Plot 4-

Shows the battery current values (A) and its changes for various acceleration input as per the drive cycle.

The peak current discharge from the battery=225.8A

The peak current charging to the battery= -163.7A

Plot 5-

Show the battery state of charge SOC(%) and its changes corresponding to the driving inputs.

The state of charge decreased from 80% to 75.5% of charge in a time period of 49seconds, for the specified driving conditions.

Plot 6-

Show 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. The maximum miles that the car run per gallon of fuel equivalent= 21.45 miles, for the given vehicle at the spedified driving conditions.

Observation(PURE electric Vs HYBRID electric vehicle with same load conditions)-

1. The electric vehicle when compared with hybrid electric vehicle with the same environmrnt 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 motor alone, but hybrid vehicle when it combine the torque of both motor and its engine it is higher than the electric vehicle 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 nickle metal hybrid battery the discharge 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 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 number of both of these cars.
4. Electric vehicle produces zero emissions whereas the hybrid one's produce waste gas emission. THese are some observations from the above comparision of simulation Powertrain Blockset.