"[Music] thank you [Music] hello and welcome back students in this video we are going to model a Powertrain the purpose of the powertrain modeling is to understand the data related to the batteries motor parameters and the forces acting on the vehicle so these are the outputs what we have got from powertrain modeling the numbers of cells in the series and parallel which will be useful for Designing the battery pack then to estimate how the resistive Force are acting on the vehicle based on the input of our velocity profilethe variations of the wheel speed and the motor speed requirement are based on the effective gear ratios for Batteries battery power requirements battery current requirements battery C rating state of charge how state of charge is remaining in our battery pack after one complete cycle the battery capacity in ampere hours and Watt hours here are the variations if you see the variation of the wheel speed and the wheel torque for a given velocity input this is the wheel speed and the torque required at wheel so thetorque required at the wheel is around 200 newton meters and the wheel speed is around 600 RPMs after effective gear ratios this is the speed and the torque which we required from our motor so our motor should be capable of giving 50 Newton meter of torque around 3800 RPM for a specified gear ratio this is how the aerodynamic forces is according to the velocity profile input given to the vehicle and this is the acceleration force the velocity profile input given to our model is this which we got from Optimum lab which youwill be learning after in this course so this is how the aerodynamic force is according to our input as a aerodynamic force is proportional to the square of the velocity so it gives similar shape to the velocity profile input which we have given this is the acceleration force the force is negative shows the strong D acceleration as you can see here the speed has dropped from 50 to 30 kilometers per hour there is a strong D acceleration and 60 to around 38 again there is a strong de acceleration so the values in the negative shows thestrong D acceleration and the positive values shows the strong acceleration the gradient force is zero as there is no slope and the rolling resistance is constant as it does not depend on the velocity input or we can say rolling resistance is independent of vehicle speed this is the battery current which we require from the given input or the profile input so it requires around 200 amperes of battery pack and the battery C rate should be around 8C the cell which we have used to estimate the battery C rate and the batterycurrent is the kokum cell which is capable of 31 amperes and has continuous current of 8C and maximum C rate is 15 C which nominal voltage is 3.6 volts it is the same cell which we have modeled previously the state of charge remaining after completing the complete cycle is around 96 percent so four percent of the charge is used in one complete cycle if we want to change the vehicle parameters like rolling resistance coefficient or the coefficient of drag frontal area gear ratios and others so instead of opening every sub blockand changing the parameters we can easily change by going into modeling click on model Explorer model workspace the powertrain model here we have already defined the parameters so these are all the parameters like Tire radius gross vehicle Mass coefficient of rolling resistance slope frontal area coefficient of drag gear ratios transmission efficiency so we can easily change all the parameters from here initially from the source and run it again so this makes the model more simple and easier to run every time so to give the velocity profile inputwhich we have shown earlier from the optimum lab which we have obtained like this profile if you want to give input for model first of all we have to obtain the data from this graph foreign for this click on the add-on button search the search for grab it and open the first one I have already installed this so I will open the folder click on grab it dot m and run that file one window will open and you can load the image and you will load it and we will load it this is the graph which we have obtained from our Optimum labwe have to calibrate the X and the y-axis so click on the origin of x-axis just click it and enter the value as 0 at the max value as x axis is 60. foreign click on the origin of y-axis and give it 10 and max value which is 65 once we have calibrated the X and the y axis we have to grab the points so click on grab points and start grabbing it how many points we require we can estimate that by clicking closer to it so follow the profile and follow it and here we can see the preview of how we are grabbing the data pointsso after you complete whole profile just click on grab Point again and here we can see the data which we have obtained we can save it as mat file and also rename the file so I have already obtained the data points and I have stored it as data002 matte file we have taken formula Student Competition team data when we talk about commercial vehicle we we can follow the standard profiles like FTP 75 or wltc Etc so I have one profile here in CSV format so if you want to load this profile in our profile so just double click on itand save it as numeric Matrix file and click on the import selection so here we can see we have loaded FTP 75 in our model go to from workspace block put here FTP 75 click on apply and ok and run the model so I will click here and we can see the value of 60 because our first profile was for 60 seconds but this profile is for 1875 seconds so to change the value click on modeling go to model Explorer model workspace and change the time here to 1875 seconds theprofile limit is for 17.5 so just re-initialize from the source and we run it again and here we can see the profiles how the FTP 75 is the wheel speed requirements the wheel torque requirements after certain gear reduction the motor torque requirement and motor speed requirement from our motor or from your motor and similarly we can see the current variations battery C rate requirements and motor power requirements so to start the modeling click on new button first we require from workspace block toinput the velocity profile we will name it as velocity profile input foreign before modeling and other blocks let's install the model parameters go to Untitled model workspace in data source select Matlab code here we will save our vehicle parametersand it will be easy for us to change it and run it according to our needs foreign first will be the radius of the vehicle that is 0.254 in meters second in Gross Vehicle Mass that is 330 kgs foreign which is a product of gross vehicle Mass into 9.81 meters per second Square foreignof rolling friction is CFR that is a 0.015 next is slope of road that is slope angle that is zero Radian frontal area that is AF 1.1 meter Square the coefficient of drag that is 0.4then the gear ratio I am giving it as 6. transmission efficiency that is 90 percent so 0.9 the motor efficiency again 90 percent that is 0.9 the motor controller efficiency that is 0.95 that is 95 percent then battery voltage that is 72 volts the cell voltage of kokum cell that is 3.6 volts that is a nominal voltage cell capacity as it is 31 ampere hours foreign distance that is total lab distance that is 0.787 meters which we have obtained from Optimum lab range required from our battery pack so we require 20 kilometers range for a single charge foreignto complete one lap as we obtain from Optimum lab which is 60 Seconds after we Implement all the vehicle parameters click on apply and re-initialize from source so here we can see in our model workspace we have opened the data close it for now we require one subsystem block and name it vehicle model double click on it there is one input for our model that isthe velocity profile and name it velocity profile in kmph foreign which we have obtained in the vehicle wheel speed and the wheel torque required for a given velocity input so hold the Ctrl key click and drag it to copy the output port we will name it wheel speed in terms of RPM and second in wheel talk in terms of Newton meter as the velocity is in kilometers per hour but we need meter per second so at the gain block to convert it in gain block and divide the kmph velocity by 3.6 to convert it intometers per second and name it kmph to MPS foreign so to open the wheel speed and wheel torque we need two subsystem block name the first one as wheel speed estimation and second one as we'll talk estimation foreign speed estimation and name the input Portas velocity input and the output port and wheel speed in RPM so the formula used for determining the wheel speed is velocity multiplied by 60 divided by 2 pi r R is the radius of the wheel so we have velocity we required one constant block so here we will give 2 pi into RW radius of the wheel then the gain block to multiply by 60.and the Divide block foreign speed in terms of RPM so see the variation of speed according to the velocity profile input so have the go to block and name it wheel speed keep tag visibility Global because we have we will see all the output later foreign if it is a local then we will be able to use the go to block in this wheel speed subsystem block only next is the wheel talk estimation nowclick on it so here name it as velocity in meter per second as the wheel talk is dependent on the force acting on the vehicle so we need to determine all the forces acting on the vehicle that is the aerodynamic Force rolling resistance force gradient force and acceleration force and multiply it with radius of the wheel to get the wheel talk so for estimating the force acting on the vehicle we need four subsystem block foreign key click and drag it to copy all theblocks and name it as rolling resistance force gradient Force aerodynamic force and acceleration force foreign so open the rolling resistance force the formula for estimation the rolling resistance force is f role is equals to GVW into coefficient of rolling resistance into cos that is the COS Theta foreignand as it does not depends on the velocity so delete the input port and insert the constant block by double clicking on the window we require three constant block and copy it first line is g g v w second is CRF coefficient of rolling resistance foreign block to open cos Theta and the product block gives the number of input as 3 and just connect them and here we willobtain our rolling resistance force foreign block to visualize the result as at last name it as rolling resistance and give tag visibility AS Global and apply it okay then go to gradient Force the formula for it is GVW multiplied by sine Theta where the Theta is in Radianso it does not depends on the velocity delete the input port we require the constant block we require two constant blocks so just copy them first is GVW and second is the slope again angle multiply with sine Theta so um insert the sine block and the product block so here we will obtain the gradient Force insert one more go to blockname it gradient Force foreign then go to aerodynamic Force block the formula is f Arrow equals to half row that is the density of the am into frontal area into coefficient of drag into square of velocity which is in meter per second then we require four constant block copythe block foreign five second is rho that is the air density so to add air density go to model Explorer model workspace and add air density equals to 1.225 kg per meter cube now click on re-initialize from Sourcecloser go to wheel talk estimation aerodynamic Force air density then frontal area and coefficient of drag here we have to insert the square block for velocity square and the product block number of input as 5 connect them this will be aerodynamic Forcewe need one go to block and name it as aerodynamic Force foreign Force the formula for acceleration force is gvm into derivative of velocity foreignhere is the velocity in meter per second we require one constant block that is gvm derivative block and the product block foreign Force insert go to block and name it acceleration force foreignas we know practice force is the sum of all the forces so we require add block and number of input is 4 so list of sign is 4 now connect all the forces to this add block as we know that real talk is total tactive Force multiplied by uh radius of wheel so add one constant block name it RW one product blockand connect it to real talk give one go to block to estimate the real talk foreign give them the velocity input and we will obtain the wheel speed and wheel torque foreign so after estimating the wheel speed and torque and if we require how much torque is required from the motor we requirethe transmission model we need one more subsystem block name it as transmission model foreign so here we require two inputs so copy one input name it as wheel speed and wheel torque the output which we get from the modelis the amount of speed and the torque required from the motor foreign so name it as motor speed and motor torque the formula required for estimating the motor speed is product of wheel speed NW into gear ratio foreign [Music]torque we have to divide the wheel torque by transmission efficiency multiplied by gear ratio so insert one constant block that is the gear ratio product of having two inputs and we get the motor speed so add one go to block and name it as motor speedand to estimate the motor torque we require transmission efficiency so add one constant block double click on it and give it a name foreign block to multiply the gear ratio and transmission efficiency and one divide block and we will get the motor talk after I've after one more go to block and name it as motor talk foreignmodel now we will connect the input next is to estimate the motor power required from motor add one subsystem block and name it as motor model double click on it as there is a two input copy the input port and name it as motor speed and motor talk and the output will be motor power in terms of whatso to estimate motor power we require motor useful power that is mup and then we will divide the motor useful Power by motor efficiency to estimate the actual motor power requirement from battery pack so motor useful power is product of 2 pi into motor speed into motor torque divided by 60. and motor actual power is motor useful power divided by motor efficiency add one constant block that is 2multiplied by pi divided by 60. foreign so once we have obtained the motor useful power we want to drive the motor efficiency add one more constant block that is motor efficiency and one divide block and then we get the motor power so add one more go to block to visualizethe result and name it as motor power foreign so we are done with the motor model so let let us connect the inputs next thing is to estimate the battery parameters we require one subsystem of battery and name it as battery modelto estimate the battery power requirements so the formula is battery power is equals to the motor power divided by motor controller efficiency as the motor power depends on torque first we have to take the positive value as motor power can also be a negative value as our torque can be negative due to De acceleration so for estimating the motor power we require the positive value insert one switch block for the switchblock we will give the motor power in input into this second input port if the motor power is greater than 0 we will continue with the same motor power if it is less than zero we will give the output as 0. add one more constant block and give the value 0 and connect so once we get the motor power add one more or gain block to divide it by motor controller efficiency add one go to block so the more output which we will getting in the battery power is in Wattsso estimate the energy consumption per kilometer we have to integrate the battery power and divide it by lab distance we will get the motor uh battery consumption per kilometer that is in watts per kilometer so the formula is watts per kilometer is integration of battery power divided by lap distance multiplied by 3.6 multiplied by 1000. so we require one integrator block foreign of the battery power to integrator block add one gain block here divide by 3.6 multiplied by 1000. that is the conversion of joules to what are and again one gain block to divide bylab distance to get the water per kilometer foreign go to block so the output we will get is what are per kilometer so if we multiply the water per kilometer we will get the battery capacity in terms of Watt hours foreign capacity in what what hours equals the what hours per kilometer multiplied by the range add one gain block give the input ofbattery hours per kilometer and multiply by the range so we get the battery capacity in what hours so once we get the battery capacity in Watt hours if we divide the battery capacity in Watt hours by battery voltage we get the battery capacity in ampere hours foreign so the battery capacity in amperes equals to the battery capacity in watts are divided by battery voltageat gain block connect the battery capacity in Watt hours divided by battery voltage add one go to block name it as battery capacity in ampere hours so once we get the battery capacity in ampere hours we divide it by capacity or the cell capacity of a single cell we get the number of cells in parallel one more gain block and divide by cell capacity one more go to block and sell inparallel now to estimate the number of cells in series we need to divide the battery voltage by cell voltage so add one constant block that is the battery voltage at one gain block to divide it by cell voltage foreign so here we get the cells in series thank younow to estimate the battery current we have to divide the battery power by battery voltage so add one gain block one divided by battery voltage add one go to block here we will get the battery current once we get the battery current so if we divide by the battery capacity in ampere hours we will get the battery C rate so add one constant block and here wewill name it as battery capacity in ampere hours we have to change this value once we run it we get the battery capacity in ampere hours so just flip the block and add one divide block again flip this block and connect the input foreign will be connected to the battery current as it is as it has to be divided by battery capacity in ampere hours add one go to block to estimate the battery C Ray again flip this block connected and this is the battery C rate now in order to estimate the state ofcharge we will insert one more sub system block and name it as SOC just open it the formula for estimating the soc at time T is SOC at time T minus 1 plus or minus integration of current with respect to the time divided by the cell battery capacity in ampere hours multiply by 3 6 double zero foreign here the plus sign is used for chargingand minus sign is used for discharging so here we require two input battery capacity and current foreign and battery capacity in ampere hours add one gain block to multiply the battery capacity with three six double zero and one integrator block and one divide blockso we have estimated this integration part initially we are consuming at time 0 our SOC is 100 percent so add one constant block and keep the value 1 as it is hundred percent and add one subtract block to subtract the value to connect it to the positive and the integration to the negative add one gain block to convert this decimal to percentage so multiply by 100 [Music] and here we will get the soc so add one go to block for visualizing the SOC foreignthere is no output from the soc so just delete the output port just connect the input so current and battery capacity so we are almost done with the powertrain modeling and we are left with the visualization of the results so click uh so add the from block and here click on the updates and insert the number of cells in series just copy this block and change it to number of cells in parallelto visualize the result we require a display block just connect them now to visualize the forces acting on the vehicle insert the from block as there are four forces so just copy and copy the from block and name it as acceleration force next is aerodynamic Force next is rolling resistance forceand the last one is gradient Force add one scope block for displaying the graphs double click on the scope block go to the settings give number of inputs as 4 and change the layout as 2 by 2 Matrix apply and close it connect the ports name the signal as acceleration forceaerodynamic Force rolling resistance force and gradient Force so to estimate the wheel speed we'll talk motor speed motor torque and the block again again we require four blocks and name it wheel speed wheel torque motor speed motor top copy this scope block and connect theblocks as well as the signals foreign foreign we have to estimate the battery parameters again insert the from block and give name motor power copy the block and change it to thebattery power again copy the block and change it to the battery current copy the block and change it to the battery C rate copy the block and name it as SOC insert the scope block go to settings and change the number of inputs as 5 and Matrix foreignthe signal as motor power in Watts battery power in Watts battery current in amperes battery C rate and change and state of charge foreign of the battery capacity in ampere hours and Watt hours so add from block name it as battery capacity in ampere hours foreigncopy the block and change it to the battery capacity in Watt hours again copy the block and change it to Watt hours per kilometer we require the display block and connect them foreign modeling go to simulation and change the stop time to time required to complete one lap so we have name it as time while we have while we save the values so just give the stop time as time and click on the Run button here we have obtained the batterycapacity as 29.36 so open this model and change the capacity to 29.36 and run this model so this is what we have seen like the battery current required is around 200 amperes the battery power is 16 kilowatts the motor power consumption is around 16 kilowatts but here we can see the negative values this negative values can be used for regeneration but as we are not using this regeneration model in state of charge you can see there is no upgrade there is downgrade so after one complete cycle it isconsuming four percent uh charge and we have the rest 96 percent of state of childhood SOC and the battery C rate required is around 75 so sorry 7.5 C discharge then the wheel speed required is around 600 RPM and the wheel torque required is around 200 newton meters after gear reduction we required 15 newton meters and around 3800 RPM from our Motors so our motor should be capable of delivering 50 Newton meter at 3800 RPMs this is the force variation this is the acceleration variation as the negative value denotes the strongde-acceleration the aerodynamic Force variation which is similar to the velocity wave profile input which we have given as it depends on the velocity the rolling resistance remains constant as it does not depends on velocity and the gradient force is zero as there is no slope thank you very much."

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