Lesson Notes By Weeks and Term v4 - SHS 3
INTRODUCTION TO VEHICLE TECHNOLOGY
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INTRODUCTION TO VEHICLE TECHNOLOGY
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Applied Technology
Class: SHS 3
Term: 1st Term
Week: 7
Grade code: 3.1.2.LI.5
Strand code: 1
Sub-strand code: 2
Content standard code: 3.1.2.CS.1
Indicator code: 3.1.2.LI.5
Theme: AUTOMOTIVE TECHNOLOGY
Subtheme: INTRODUCTION TO VEHICLE TECHNOLOGY
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
This lesson introduces learners to the fundamental principles of Electric Vehicles (EVs). As Ghana grapples with fluctuating fuel prices and increasing environmental concerns, understanding alternative vehicle technologies is crucial. EVs represent a significant shift from the traditional petrol and diesel cars we see every day. This lesson will demystify how they work, exploring their main components and operational principles. This knowledge is not just for future automotive technicians but for all citizens who will witness and participate in this technological transition.
A. What is an Electric Vehicle (EV)?
An Electric Vehicle is a vehicle that is powered by one or more electric motors, using electrical energy stored in a rechargeable battery pack. Unlike the cars we are most familiar with, EVs do not have a petrol or diesel engine, a fuel tank, or an exhaust pipe. They are quiet, produce no tailpipe emissions, and are mechanically simpler. Key Distinction: Internal Combustion Engine (ICE) Vehicle: Burns fuel (petrol/diesel) in an engine to create motion. Battery Electric Vehicle (BEV): Uses electricity from a battery to power a motor, which creates motion. (This lesson focuses on BEVs). B. Main Components of an Electric Vehicle
Let's look at the "organs" of an EV. We can use a simple diagram or video to illustrate these parts.
*(Teacher should draw a similar diagram on the board or use a chart/projector)* Traction Battery Pack: What it is: A large, rechargeable battery that stores the electrical energy needed to power the vehicle. Function: It is the "fuel tank" of the EV. Its capacity is measured in kilowatt-hours (kWh). A larger kWh value means the car can travel a longer distance on a single charge (longer range). Analogy: Think of it as a giant version of your smartphone battery. Just as your phone battery stores power for calls and apps, the traction battery stores power for driving. Electric Motor (Traction Motor): What it is: A device that converts electrical energy from the battery into mechanical energy. Function: This mechanical energy is used to spin the wheels and move the car. It provides instant torque, which is why EVs can accelerate very quickly and smoothly. Analogy: It works like the motor in a standing fan or a blender, but it is far more powerful and efficient. Power Electronics Controller (Inverter): What it is: The "brain" of the EV's power system. Function: It manages the flow of electricity between the battery and the motor. It takes DC (Direct Current) power from the battery and converts it into AC (Alternating Current) power for the motor. It also controls the speed of the motor based on how hard the driver presses the accelerator pedal. Analogy: It acts like a sophisticated dimmer switch for a light bulb, precisely controlling how much power goes to the motor to make it spin faster or slower. On-Board Charger (OBC): What it is: A component inside the car that facilitates charging. Function: It converts the AC electricity from your home socket or a public charging station (from ECG/NEDCo grid) into DC electricity that can be safely stored in the battery pack. Analogy: This is like the "charger block" or "adapter" for your laptop or phone. You plug the cable into the wall (AC), but the block converts the power to what the device's battery needs (DC). Charging Port: What it is: The socket on the exterior of the vehicle. Function: This is where you plug in the charging cable to connect the vehicle to an external power source. Analogy: It's exactly like the charging port on your mobile phone. Transmission (Single-Speed): What it is: The mechanical link between the motor and the wheels. Function: It transmits the turning force (torque) from the motor to the wheels. Most EVs have a single gear because electric motors are efficient at a very wide range of speeds, unlike ICEs which need multiple gears (1st, 2nd, 3rd, etc.) to operate efficiently. Regenerative Braking System: What it is: An intelligent braking and energy-recovery system. Function: When the driver slows down or brakes, the electric motor operates in reverse, acting like a generator. It captures the car's kinetic energy (energy of motion) and converts it back into electricity, which is then sent back to the battery pack. This increases the vehicle's overall efficiency and range. Analogy: Imagine pedalling a bicycle to power a small light (a dynamo). Now, imagine the wheel's motion itself is turning the dynamo to recharge a battery. That's regenerative braking. C. How an Electric Vehicle Operates: A Step-by-Step Explanation Charging: The owner plugs the EV into a charging station or a wall socket via the charging port. The On-Board Charger converts the incoming AC power to DC and fills up the traction battery pack. Starting Up: The driver presses the "Start" button. There is no engine noise. The car is silent but ready. The Power Electronics Controller is activated. Acceleration: The driver presses the accelerator pedal. The pedal sends an electronic signal to the Power Electronics Controller. The controller draws a specific amount of high-voltage DC power from the battery pack. The controller (specifically, the inverter part) converts this DC power to AC power. This AC power is fed to the electric motor. Movement: The electric motor uses the AC power to generate torque, rotating its shaft. This rotation is transferred through the single-speed transmission to the wheels, causing the vehicle to move forward. The more the driver presses the accelerator, the more power the controller sends to the motor, and the faster the car goes. Deceleration (Slowing Down): The driver lifts their foot off the accelerator or presses the brake pedal. The regenerative braking system is activated. The electric motor reverses its role. It now acts as a generator. The momentum of the wheels turns the motor, generating electricity. This electricity is sent back through the controller to the battery pack, recharging it slightly and extending the vehicle's range. This process also creates resistance, which helps to slow the car down.