Challenge

Final Project: Design of an Electric Vehicle

SSenthilkumar Subramanian4 Apr 2022

Objective:

To create a MATLAB model of electric car which uses a battery and a DC motor. Choose suitable blocks from Powertrain block set. Prepare a report about your model including following

1. System level configurations

2. Model parameters

3. Results

4. Conclusion

Electric Cars:

All-electric vehicles (EVs), also referred to as battery electric vehicles, have an electric motor instead of an internal combustion engine. The vehicle uses a large traction battery pack to power the electric motor and must be plugged in to a wall outlet or charging equipment, also called electric vehicle supply equipment (EVSE). Because it runs on electricity, the vehicle emits no exhaust from a tailpipe and does not contain the typical liquid fuel components, such as a fuel pump, fuel line, or fuel tank.

Key Components of an All-Electric Car

Battery (all-electric auxiliary):

In an electric drive vehicle, the auxiliary battery provides electricity to power vehicle accessories.

Charge port:

The charge port allows the vehicle to connect to an external power supply in order to charge the traction battery pack.

DC/DC converter:

This device converts higher-voltage DC power from the traction battery pack to the lower-voltage DC power needed to run vehicle accessories and recharge the auxiliary battery.

Electric traction motor:

Using power from the traction battery pack, this motor drives the vehicle's wheels. Some vehicles use motor generators that perform both the drive and regeneration functions.

Onboard charger:

Takes the incoming AC electricity supplied via the charge port and converts it to DC power for charging the traction battery. It also communicates with the charging equipment and monitors battery characteristics such as voltage, current, temperature, and state of charge while charging the pack.

Power electronics controller:

This unit manages the flow of electrical energy delivered by the traction battery, controlling the speed of the electric traction motor and the torque it produces.

Thermal system (cooling):

This system maintains a proper operating temperature range of the engine, electric motor, power electronics, and other components.

Traction battery pack:

Stores electricity for use by the electric traction motor.

Transmission (electric):

The transmission transfers mechanical power from the electric traction motor to drive the wheels.

Steps to build and simulate a model in simulink:

1. Vehicle Body:

Simulink have a build in block for vehicle body in simscape -> Driveline -> tiers and vehicles.
H - Hub of the vehicle / chasis
V - vehicle velocity
w - wind effect
NR - rear force
Nf- nominal force for front wheel
Beta- terrain inclination angle
if you want to now more about the block clic the help icon.

2.Modelling Tyre:

Matlab has a buid in block for modelling tyre and i use magic formula tyre bloc to model the tyre.
It has four coefficients namely B,C,D,E.
All other parameters are leave as default.
The blok has four connections,they are
N -> Normal force input
A -> axel
S -> tyre slip with respect to ground due to the force
H -> hub of the wheel

Connection between tyres and vehicle body:

They are created and convert into sub system

Now the vehicle body modeling is complited.

The hub port gives the vehicle linear movement
The terrain and wind port are used for modelling the road gradient and wind effect to the car.
The real and front axel are used to apply the driving and brake forces to the rear and front axel respectively.

The Brake Unit:

In order to model the brakes for the vehicle we use the disk brake model from the simscape mechanical library
It has 3 terminals N- >input brake force
B-> mechanical reference
F-> Output brake force.

Gear subsystem:

Simscape library has a simple gear block for modelling the gears for a vehicle.

The Driving Source:

For an electric vehicle the source for the propulsion is The motor powered by Battery

The subsystem for The Motor and controller block are

Motor (BLDC Motor)
Invereter Block (To perform commutation for Bldc motor)
Buck converter (For speed controlling the motor)
Sensor( To find the position of rotor)
Comutation Logic( To perform commutation electronically)

BLDC Motor:

Battery:

Fig: Battery individual cell

cell nominal voltage: 12v

series Resistance : 0.001 ohm

Time constant R = 0.0005 ohm

C = 5000 F

Fig: Battery Subsystem

Buck Converter/Speed Controller:

Buck converter

The buck converter is to regulate the Batter voltage(48v) interms of duty cycle(0 to 1)

Inverter:

fig: Inverter subsystem

Fig: Inverter Parameter Setting

Sensor:

Fig: Sensing Rotor position

To perform the commutation we need to know the position of the rotor

Commutation Logic:

Fig : Switching Pattern

Closed Loop control system:

Result-1:

BLDC powered DC EV:

MODEL

OUTPUT:

Result-2:

DC powered EV

Output:

Final Project: Design of an Electric Vehicle

Electric Cars:

Key Components of an All-Electric Car

Ship work like this
in your own course.

Talk to a career counsellor

Electric Cars:

Key Components of an All-Electric Car

Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.