Week-4 Challenge WOT Condition Part-2
QUESTION 1 :
What is the difference between mapped and dynamic model of engine, motor and generator? How can you change model type?
MAPPED ENGINE : Mapped engine is the default settings in powertrain blockset. It is used to measure performance parameters of the vehicle by using standard lookuptables which are prefered to the system. This type of modelling is less occurate. The lookup tables values are based on the values of brake torque , commanded torque and engine speed.
if any other parameter like input engine temperature is selected then lookup tables values are also a function of the temperature parameter. The data extracted from look tables are air mass flow, fluel flow , emission data, exhaust temperature and efficiency. THis data is used to find out other parameters which are neede by tthe end user.
DYNAMIC ENGINE : The type of model uses real time data fed by the user at run time for modelling. This model is more accurate than mapped engine model. This type of model is used when the data of subsytem of a vehicle is required. we can calculate brake torque , fuel flow, port gas mass flow, exhaust temperature and effciency. This data is used to find out other parameter which are needed by the end user.
MAPPED MOTOR : the mapped motor works in torque control mode. This type of motor is used when the user requires a faster simulation and doesnt have the knowledge of motor parameters. the output torque and refernce torque is compaired and changes are made. Input torque or speed can be specified, electrical losses and maximum motor power and torque can be definrd.
DYNAMIC MOTOR : In the dynamic motor a three phase interior magnet synchronous motor is used. The blocks uses three phase input voltage to regulate the individual phase currents, allowing control of the motor torque or speed. This block is used when the use rknows what oarameter are to be used in that perticular simylation. This motor is more accurate.
MAPPED GENERATOR : The mapped generator block is also similar like othe rblocks. Most of teh data required is taken from the lookup tables corresponding to the given input parameter. Its simulation time is less.
DYNAMIC GENERATOR : The dynamic generator involves user enterning the parameters manually during the run time for their perticular application. The reasult take time and are more accurate.
QUESTION 2:
How does the model calculate miles per gallon? Which factors are considered to model fuel flow?
For a conventional gasoline vehicle the fuel efficiency is calculated via miles - per - gallon (MPG). However, fuel efficiency for hybrid models is calculated via miles per gallon equivlent MPGs. MPG is the number of miles your car can drive per gallon of gas.
Figuring out an mpgs rating is a little more complicated. since against that use an alternative source of fuels cant be measured by liquid gallons of fuel. the mpg rating is calculated by figuring out the number of miles a vehicle can go using the same energy content as a gallon of gas. the EPA calculates that 33.7 kilowatt- hours of electricity is the equivalent to one gallon of gas.
Here , three different inputs are taken into consideration
1.vehicle spped.
2. fuel flow.
3. Battery power.
THe vehicle spped input is in m/s which is converted into miles by multiplying with 0.000621371.
Similarly , the kilogram of fuel is converted into cubic meter by multiplying it with 264.172. The mile value and gallon value is used to find MPGof the vehicle.
NOw the battery value is initally converted from watts to kwh by dividing with100 and then to gallon equivalent by again dividing it with 33.7
The divide the value by 3600 to get in per second and multiply by 0.00378541 to grt the value in cubic meter per gallons.
QUESTION 3.
Run the HEV ReferenceApplication with WOT drive cycle. Change the grade and wind velocity in the environment block. Comment on the results.
coclusion Trace velocity target actual.
Top velocity acheived = 50.1mph
time taken to accelerate = 29.034sec
time taken to deaccelerate = 3.226sec.
plot2 motor &engine rpm
top motor rpm= 12550 rpm
top engine rpm = 6188rpm
plot 3 motor &engine torque
maximum motor torque 50N-m
maximum engine torque = 205.3N-m
plot4 batter current
The battery current is at its maximum value of 167amper when full throttle is applied by the user.it reduces drastically to the value of negative 150 during deceleration of the vehicle.
Plot 5 battery SOC :
The battery SOC falls from 60 to40% during the acceleration period of vehicle and its slightlly increase to 43% during deceleration dur to regenerative braking.
Plot 6 fuel economy
Maximum fuel economy achieved = 6.056.