Week-4 Challenge WOT Condition Part-2

 

Week-4

Challenge WOT Condition

Sir, Please find attached and pasted explanation along with necessary matlab files

 

<!-- [if !supportLists]-->1.   What is the difference between mapped and dynamic model of engine, motor and generator? How can you change model type? 

Mapped models are basically steady state models which are time invariant, where the variables like speed and torque are predefined. Here we need to have complete knowledge on past and future demands to derive the preset values.(heuristic operation rules)

Runs faster

Dynamic models are based on real time feedback values and they are optimized based on system components

Open EvReference Model  from the power train blockset and Follow the steps

 

Passenger caràElectric Plant àGenMapped/MotMappedàGenMapped/GenDynamic & MotMapped/MotDynamic

Motor:

Motor Mapped:

Inside the mapped motor we can see from the block, Maximum Torque, Maximum Power, Torque control time constant are fixed and they can not be changed dynamically according to situation and such type of models are called Mapped models.

 

Motor Dynamic:

In the motor dynamic block there is optional PMSM controller where the speed and basic information are used as feedback for the dynamic control

 

 

To enable motor mapped to motor dynamic

Right click on motor modelàClick variantàOpenà Choose the variant we need

 

 

To label the variant we chose,

Right click on model àVariantàLabel Mode active choiceàChoose to rename

 

Model type can be removed by right click on the subsystem we want to change and then click on subsystem and model reference and then convert to variant system

 

 

 

Like motor, Generator and Engine also have mapped and Dynamic type. It is our priority to keep the model mapped or dynamic using the variant system

 

<!-- [if !supportLists]-->2.     <!--[endif]-->How does the model calculate miles per gallon? Which factors are considered to model fuel flow? 

In the HEV reference model, Calculation of Miles per gallon is available in Visualization block as it comes under performance evaluation

Visualizationà Performance calculation

Miles/gallon is Equivalent to Kilometer/Litre or miles/Litre.

1 Litre = 0.26412 gallon as referred in google.

For instance:

KilometerPerLitre/MilesPerGallon = Total distance travelled(Km/Miles) /

Amount of Fuel used ( Gallon/Litre)

 

 

 

From the above diagram we can see that flow rate is measured in metre cube per second and it is added with battety equivalent of metre cube value and is converted to gallon by the gain of 264.172

Also, we see that vehicle speed is received from earlier block xdot, which is velocity reference which is squared and taken square root to convert the value to real number, sometimes there is possibility of getting negative value, hance to avoid we take squareroot and then through integrator to convert it back to meter

AccelerationàVelocityàSpeed

 

<!-- [if !supportLists]-->3.     <!--[endif]-->Run the HEV Reference Application with WOT drive cycle. Change the grade and wind velocity in the environment block. Comment on the results.

Search in Matlab documentation “ HEV reference application” and open Multimode model

Click on the drive cycle and select WOT and change parameters according to need

 

 

 

After Entering the drive cycle WOT value and keeping all the other parameters same and run the simulation for 100s.

For the first 5 seconds, the input speed is zero and the initial speed of the vehicle is zero.

From t=6 to t=60 the vehicle is given full throttle to obtain a speed of 100m/s.

From t=61 to t=100 the vehicle is set to decelerate from 100m/s to 0m/s

Scope can be viewed by following visualizationà Performance and FE scope

Case 1: WOT parameters set with out changing Grade=0 and Wind velocity=0 

 

Case 2: WOT parameters set changing Grade=7 and Wind velocity=0

 

Case 2: WOT parameters set changing Grade=7 and Wind velocity=10

 

 

Increasing gradeability and wind velocity delays the vehicle from achieving expected speed

<!-- [if !supportLists]-->4.     <!--[endif]-->Keeping all other parameters same, compare the simulated results of hybrid and pure electric powertrains. 

In EV Reference application model , we set WOT parameters set changing Grade=7 and Wind velocity=10

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Parameters	HEV	EV
Trace Velocity	Slower	Faster and smoother
Battery Current	Peak varies	Constant Peak current
Battery SOC	Much reduced	Not much
Motor Speed	Less RPM	More RPM
Motor Torque	Higher than EV	Lesser than HEV
MPG	19.88 lower	14.36 higher