Final Project: Design of an Electric Vehicle

EV BATCH 17

                                                           DESIGN OF ELECTRIC VEHICLE

AIM:

To create a matlab model of ELECTRIC VEHICLE which uses a battery and DC motor by using a matlab.

Objective:

objective of the project are

       1.System level configurations

       2. Model parameters

       3. Results

       4. Conclusion.

Explanation:

what is an Electric vehicle?

• An electric vehicle (EV) is a vehicle that uses one or more electric motor propulsion.
• It can be powered by a collector system, with electricity. from extravehicular sources, or it can be powered autonomously by a battery. (sometimes charged by solar panels, or by converting fuelto electricity using fuel cells or a generator). 
• EVs include, but are not limited to, road and rail vehicles, surface and under water vessels, electric air craft and electric space craft.
• EVs first came into existence in the mid-19th century, when electricity was among the preferred methods for motor vehicle  propulsion, providing a level of comfort and ease of operation that could not be achieved by the gasoline cars of the time.
•  Internal combustion engines were the dominant propulsion method for cars and trucks for about 100 years, but electric power remained commonplace in other vehicle types, such as trains and smaller vehicles of all types. 

government initiatives:

• Government initiatives to increase adoption were first introduced in the late 2000s, including in the US and the EU, leading to a growing market for the vehicles in the 2010s.
• Increasing public interest and awareness and structural incentives, such as those being built into the green recovery from the COVID-19 pandemic, is expected to greatly increase the electric vehicle market.
• During the COVID-19 pandemic, lockdowns have reduced the amount of greenhouse gases from gasoline or diesel vehicles. The international energy agency  said in 2021 that governments should do more to meet climate goals, including policies for heavy electric vehicles.Electric vehicle sales may increase from 2% of global share in 2016 to 30% by 2030.
•  Much of this growth is expected in markets like North America, Europe and China; a 2020 literature review suggested that growth in use of electric 4-wheeled vehicles appears economically unlikely in developing economies, but that electric 2-wheeler growth is likely. There are more 2 and 3 wheel EVs than any other type.

INDIAN Government initatives:

• India is the fourth-largest auto market  globally, and some estimates suggest there are close to 170 active investors in the country’s EV start up ecosystem. 
• Electric vehicles are a great source for smooth transportation without harming the environment. Here’s a look at what incentives the government has announced to promote electric vehicles in India and how Indian government policies and subsidies are working to promote EVs in India. 
• Here’s a look at what incentives the government has announced to promote electric vehicles in India and how Indian government policies and subsidies are working to promote EVs in India. 

• The policy’s primary objective is to accelerate EV adoption,  especially in the mass category of two-wheelers, public/shared transport vehicles & goods carriers, target 25% Battery Electric Vehicles in all new vehicle registrations by 2024.

• Also,  layout measures to support the creation of jobs in driving, selling, financing, servicing, and charging EVs. This policy will be valid for three years from the date of its issue. 

• So, these were some of the government incentives and policies that have been taken to promote electric vehicle companies and their manufacturers to make a large number of electric vehicles in India. As the Government of India is claiming to reach all-electric vehicle in India by 2050 and 40% of total fleets by 2030.  

• India has a lot to gain by converting its ICE vehicles to Electric vehicles at the earliest. Its oil-import bill would considerably reduce. ICE vehicles are a significant contributor to pollution in cities,  and their replacement with EVs will improve air quality. There is a possibility that we can become leaders in small and public electric vehicles. 

• The government has launched the following initiatives to Promote Electric Vehicles in India:  

  • Under the new GST system, GST on EVs is reduced from 12% to 5% against the 28%  GST rate with up to 22% for conventional vehicles.  
  • The government has proposed the exemption of registration fees for battery operated/electric vehicles to promote eco-friendly vehicles in the country. 
  • The Ministry of Power has also allowed the sale of electricity as a ‘service’ for electric vehicles’ charging. It will attract investors into the charging infrastructure. 
  • Also, The government has granted an exemption to battery-operated transport vehicles and vehicles that run on methanol and ethanol fuels from the requirements of the permit.

• Nitin Gadkari, the Union Minister for Road Transport and Highways (MoRTH), announced in Parliament that phase-II of the FAME India scheme is being implemented with total budgetary support of ₹ 10,000 crores. With this, the government has planned to support about 62,000 electric passenger buses and cars and 15  lakhs electric three- and two-wheelers in India.

Indian Electric Car Policy 2020  

• Currently, states including Delhi, Gujarat and Telangana have a firm EV policy in place with others expected to follow. Delhi is poised to be the nerve centre of India’s electric vehicle revolution. 
• India expects 25% to 35% electric two-wheeler penetration and 65% to 75% in electric three-wheelers by 2030, with passenger vehicle electrification.  
• CNG-driven public transport fleet to e-mobility, Delhi has been an avid promoter of clean mobility solutions for a very long time. Delhi Government rolled out the “Delhi EV  Policy 2020” in August 2020. 

INDIAN GOVERNMENT  CHARGING INFRASTRUCTURE GUIDLINESS,SOME IMAGES ARE MENTIONED BELOW:

Main components of the ELECTRIC VEHICLE:

• Wheels/tires
• Battery
• Motor/generator
• Motor controller
• Power converter
• Transmission system

main blocks :

DRIVE CYCLE:

• Drive cycle is a set of data points ,which means Variation of speed with respect to time.
• The "Drive-cycle" basically is the representative of the road. Drive cycles are used to reduce the expense of on road tests, time of test and fatigue of the test engineer. The whole idea is to bring the road to the test lab (a chassis dynamo-meter) or to the computer simulation.
• It is used to identify the high speed of the vehicle,low speed of the vehicle,start-stop condition,fuel consumption,etc..
• there four main blocks interconnected with the drive cycle.

longitudinal driver block:

• The Longitudinal Driver block implements a longitudinal speed-tracking controller. Based on reference and feedback velocities, the block generates normalized acceleration and braking commands that can vary from 0 through 1.
• Use the External Actions parameters to create input ports for signals that can disable, hold, or override the closed-loop acceleration or deceleration commands. The block uses this priority order for the input commands: disable (highest), hold, override.

subsytem:

• A subsystem is a set of blocks that you group into a single Subsystem block. Establishes a hierarchical block diagram, where a Subsystem block is on one layer and the blocks that make up the subsystem are on another. Keeps functionally related blocks together. Helps reduce the number of blocks displayed in your model window.

vehicle body:

• The Vehicle Body block represents a two-axle vehicle body in longitudinal motion. The vehicle can have the same or a different number of wheels on each axle. For example, two wheels on the front axle and one wheel on the rear axle. The vehicle wheels are assumed identical in size. The vehicle can also have a center of gravity (CG) that is at or below the plane of travel.
• The block accounts for body mass, aerodynamic drag, road incline, and weight distribution between axles due to acceleration and road profile. Optionally include pitch and suspension dynamics. The vehicle does not move vertically relative to the ground.
• The block has an option to include an externally-defined mass and an externally-defined inertia. The mass, inertia, and center of gravity of the vehicle body can vary over the course of simulation in response to system changes.

Tire (magic Formula)block:

• The Tire (Magic Formula) block models a tire with longitudinal behavior given by the Magic Formula [1], an empirical equation based on four fitting coefficients. The block can model tire dynamics under constant or variable pavement conditions.
• The longitudinal direction of the tire is the same as its direction of motion as it rolls on pavement. This block is a structural component based on the Tire-Road(magic Formula) block.
• To increase the fidelity of the tire model, you can specify properties such as tire compliance, inertia, and rolling resistance. However, these properties increase the complexity of the tire model and can slow down simulation. Consider ignoring tire compliance and inertia if simulating the model in real time or if preparing the model for hardware-in-the-loop (HIL) simulation.

Simple gear:

• This example shows a simple gear coupling two inertias (shafts). The gear ratio between the follower (F) and base (B) is 2:1. Thus the angular velocity of the follower shaft is half the angular velocity of the base shaft. The follower shaft torque is twice the base shaft torque.

INERTIA BLOCK:

• By default, the block has one mechanical translational conserving port. The block positive direction is from its port to the reference point. This means that the inertia torque is positive if inertia is accelerated in the positive direction.
• In some applications, it is customary to display inertia in series with other elements in the block diagram layout. To support this use case, the Number of graphical ports parameter lets you display a second port on the opposite side of the block icon. The two-port variant is purely graphical: the two ports have the same angular velocity, so the block functions exactly the same whether it has one or two ports. The block icon changes depending on the value of the Number of graphical ports parameter.

DC motor:

• Converts input electrical energy into mechanical motion.
• a DC motor driven by a constant input signal that approximates a pulse-width modulated signal and look at the current and rotational motion at the motor output.

H-bridge:Drives the DC motor:

• During simulation, the block uses these values to calculate a more accurate value for H-bridge output voltage that achieves the same average current as would be present if simulating in PWM mode. Set the Simulation mode parameter to Averaged to speed up simulations when driving the H-Bridge block with a Controlled PWM Voltage block.

Pwm voltage block:

Generates the signal that approximates a pulse-width modulated motor input signal.

The Controlled PWM Voltage block represents a pulse-width modulated (PWM) voltage source. You can model electrical or physical signal input ports by setting the Modeling option parameter to either:

If you set Modeling option to Electrical input ports, the demanded duty cycle is

where:

• V_ref is the reference voltage across the ref+ and ref- ports.

• V_min is the minimum reference voltage.

• V_max is the maximum reference voltage.

In PWM mode, the block has two options for the type of switching event when moving between output high and output low states:

• Asynchronous - Best for variable -steo solvers — Asynchronous events are better suited to variable step solvers, because they require fewer simulation steps for the same level of accuracy. In asynchronous mode the PWM switching events generate zero crossings, and therefore switching times are always determined accurately, regardless of the simulation maximum step size.

• Discrete-time-Best for fixed -steo solvers— Discrete-time events are better suited to fixed-step operation, because then the switching events are always synchronized with the simulation step. Using an asynchronous implementation with fixed-step solvers may sometimes result in events being up to one simulation step late. For more information,see simulating with Fixed Time step-Local and global Fixed solvers.

If you use a fixed-step or local solver and the discrete-time switching event type, the following restrictions apply to the Sample time parameter value:

• The sample time must be a multiple of the simulation step size.

• The sample time must be small compared to the PWM period, to ensure sufficient resolution.

Controlled voltage source:

• The Controlled Voltage Source block represents an ideal voltage source that is powerful enough to maintain the specified voltage at its output regardless of the current flowing through the source.
• The output voltage is V = Vs, where Vs is the numerical value presented at the physical signal port.

Current sensor:

• Converts the electrical current that drives the motor into a measurable physical signal proportional to the current.
• The Current Sensor block represents an ideal current sensor, that is, a device that converts current measured in any electrical branch into a physical signal proportional to the current.
• Use the + and - ports to connect the sensor in series with the other blocks in the branch where you want to measure the current. Port I outputs the measurement result as a physical signal.

Battery block:

• The Battery block implements a generic dynamic model that represents most popular types of rechargeable batteries.

Controlled Current Source block:

• The Controlled Current Source block converts the Simulink input signal into an equivalent current source. The generated current is driven by the input signal of the block.
• The positive current direction is as shown by the arrow in the block icon.
• You can initialize the Controlled Current Source block with a specific AC or DC current. If you want to start the simulation in steady state, the block input must be connected to a signal starting as a sinusoidal or DC waveform corresponding to the initial values.

solver configuraion block:

• Defines solver settings that apply to all physical modeling blocks.

 

PS-Simulink converter:

• converts the input physical signal to a Simulink signal.

Electrical reference:

• Provides the electrical ground.

mechanical reference:

• Provides the mechanical ground.
• Converts the rotational motion of the motor into a measurable physical signal proportional to the motion.

Power gui block:

The powergui block allows you to choose one of these methods to solve your circuit:

• Continuous, which uses a variable-step solver from Simulink

• Discretization of the electrical system for a solution at fixed time steps

• Continuous or discrete phasor solution

The powergui block also opens tools for steady-state and simulation results analysis and for advanced parameter design.

You need the powergui block to simulate any Simulink model containing Simscap Electrical Specialized Power Systems blocks. It stores the equivalent Simulink circuit that represents the state-space equations of the model.

When using one powergui block in a model:

• Place the powergui block in the top-level diagram for optimal performance.

• Make sure that the block is named power gui.

 scope:

Displays motor current and rotational motion.

model and their explanation:

• The model running is based on the drive cycle.
• Drive cycle is a set of data points ,which means Variation of speed with respect to time.
• It is used to identify the high speed of the vehicle,low speed of the vehicle,start-stop condition,fuel consumption,etc..
• there are four main blocks interconnected with the drive cycle.
• here I used the FTP drive cycle.The simulation time of the vehicle is as per the FTP drive cycle which means they having the 2474sec to a complete driving.
• The below block represents the electric vehicle of the system.the drive cycle source is provided to Acceleration and decceleration of the motor.
• The Longitudinal Driver block implements a longitudinal speed-tracking controller. Based on reference and feedback velocities, the block generates normalized acceleration and braking commands that can vary from 0 through 1.
• Use the External Actions parameters to create input ports for signals that can disable, hold, or override the closed-loop acceleration or deceleration commands.
• The speed,current and state of charge are observed and analysed by using the scope.

CONSTRUCTION:

The construction parameters images are given below:

The below figure represents the drive cycle parameter and longitudinal driver parameters.The PI controller is choosen and FTP drive cycle is choosen.

The below dialog box represents the DC motor ,pwm voltage source and H-bridge.I have consider a average pwm source and frequency as 1000Hz motor specifications are explained below.

The below dialog box represents the simple gear,tire and vehicle body.I have consider the weight of the vehicle as 1200 kg. and other parameters.The tire load taken as 3000N and pak as 3500N.In gear box gear ratio taken as 6 and it should be rotated in same direction of the input shaft to get the value.other are explained below.

controller block:

there are five main components in the controller blocks are 

• DC MOTOR
• H-bridge
• pwm voltage source 
• controlled current source
• current sensor.

 

• The Dc motor mechanical part is connected with the mechanical reference and the another is connected with power connection to the transmission system and gives out to the vehicle wheels.
• Dc motor having the settings of electrical and mechanical.
• electrical part parameters are perment magnet is taken,the motor should be by rated load and speed.other parameters of armature,no load speeds ,supply voltages are given to the electrical part side.
• machanical part of rotor inertia is given to the motor.
• The electrical reference is connected with the motor part.
• H- bridge is taken as internal,averaged and load current characteristics as smooth,the input parameters are given to the H-bridge.
• H-bridge connects with the controlled pwm voltage source as well as braking command along with the solver configuration.
• the braking command is comes from the input signal of the longitudinal driver.
• The current sensor is connected with the h-bridge and dc motor to measuring the current and it should be observed in the scope .
• controlled pwm voltage source is connected with the another electrical reference and the H-bridge.
• The input can be comes from the acceleration signal of the longitudinal driver.
• DC motor given the output as a current.
• The voltage,current and deccelerations are observed by scope.

PASSANGER BLOCK:

• inside the passanger car there two main subsystems are created.
• 1.Battery
• 2.vehicle body

Battery:

• Inside the battery pack, i have choosen the Li-thium battery,the input parameters are entered in the dialog box.
• the nominal voltage,rated capacity,initial state of charge and battery reference.
• The discharge parameters are calculated automatically by clicking the dialog in discharge setting.
• The controlled current source is connected which is taken a current from the Dc motor.
• The controlled current source is used to give tha constant current to the battery to get recharge.without the controlled current voltage source the battery get damaged.
• That battery voltage and state of charge are observed in the scope.

2.Vehicle body:

• It is one of the important block of the vehicle.
• There are 4 tyres are interconnected and connected with the vehicle body.
• The tire(magic formula)are having two connection one is connect with vehicle body and another one is the free end.
• The power comes from the DC motor and enters into the transmission system.
• The transmission system having the simple gear.The simple gear parameters of gear teeth is taken as 6 and it should be running in the same direction as the input shaft to get the positive value.
• Then the power gives to the wheels.
• The wheels starts rotating after the power comes from the Dc motor.
• It gives the speed as the output it should be observed by using the scope.

Working principle:

• The working principle of the electric vehicles are
• The acceleration and decceleration cntrolled by the longitudinal driver with the help of the FTP driving cycle.
• the powers are generated by the DC motor and gives the power to the battery and transmission system.
• The transmission system gets the power from the DC motor and gives the power to the wheels along with the help of the gears.
• the power moves to the battery ,the battery get charged.the batteries are used to operating the accessories and gives the power to the start the motor.
• the speed,state of charge,current,acceleration,deccelerations are observed by using the scope.
• The results are mentioned as a plot given below.

Plots:Drive cycle speed and car speed with respect to time.

• The below plots represents the original speed which means the driving cycle speed and the car speed is the speed which should be operated by the driver.
• by observance the due acceleration and deccelaration of the vehcile the lines of the plots are similar so our simulation is running correctly and smoothly.
• while the plot move up the vehicle is get accelerated and moving and the dropping of the lines are represents the brake applied by the driver.at the 1300 sec to 2000sec the vehicle should be in the idle condition.
• The vehicle performance is in good condition as compared to the drive cycle.

Plot:2 Longitudinal driver acceleration and decceleration with respect to time.

• The above plot represents the accelration and brakes applied by driver.the acceleration should be plotted as blue color and brakes are plotted in red color.
• By observance these also moves like a drive cycle so, our simulation is running correctly.

Plot:3 Battery voltage (v)and battery Soc% vs Time.

• The above plots represent the battery voltage and state of charge of the battery.
• first of all our plot is running like a drive cycle so it is correct.
• The voltage is moves up while driving state and dropped under idle state.
• The state of charge is slowly reduced due to the driving.
• The 1300 to 2000 sec the vehicle is constant because of the idle state of the vehicle.

Plot:4 Current vs Time

• The plot represents the current flow of the vehicle.
• The current flow is similar to the drive cycle,so our simulation is correct .
• The current should vary to 150 to -150.The 1300-2000 sec is the constant state which means the vehicle is in idle condition.

Conclusion:

I have conclude with a electric vehicle is created successfully by using the matlab.