Electric Vehicles

ELECTRIC VEHICLES

Definition

Electric vehicles are the vehicles that are powered on electric power. These are also referred to as battery electric vehicles. They have an electric motor instead of an internal combustion (IC) engine. Running costs are very low as they have less moving parts for maintaining. As it runs on electricity, the vehicle emits no exhaust gases.

1. Working Principle

Electric vehicles work by plugging into a charge point and taking electricity from the grid. They store electricity in rechargeable battery that power on electric motor, which rotates the wheels. Electric vehicles accelerate faster than the traditional fuel engines. So they feel lighter to drive.

Various steps of working

Step I : Controller takes and regulates electrical energy from battery to inverter.

Step II : The inverter then sends a certain amount of electrical energy to the motor.

Step III : The motor converts electrical energy into mechanical energy (rotation).

Step IV : Rotation of the motor rotor rotates the transmission, so the wheels turn and then the vehicle moves.

Step V : When the brakes are pressed, the motor becomes an alternator and produces power, which is sent back to the battery.

2. Components of EV

The followings are important and essential components in a electrical vehicles.

1. Battery: It provides electricity to power the vehicles.

2. Charge port: It allows the vehicle to connect to an external power supply to recharge the battery.

3. DC/DC converter: It converts higher voltage DC power from battery to lower voltage DC power.

4. Electric motor: It drives the vehicle's wheels.

5. Onboard charger: It converts AC electricity to DC power for charging the battery.

6. Power electronics controller: It controls the flow of electrical energy from battery to motor and controls the speed.

7. Thermal system (cooling): It maintains the proper operating temperature range of the engine, motor etc.

8. Transmission: It transfers mechanical power from the motor to drive the wheels.

3. Plug-in electric vehicles

Any motor vehicle that can be recharged from any external source of electricity such as wall sockets, rechargeable battery packs are called plug-in electric vehicles.

1. Types of plug - in electric vehicles

They can be further divided into two types.

1. Battery Electric Vehicles (BEVs) (or) pure electric vehicles (or) fully electric vehicles.

2. Hybrid type vehicles

(a) Hybrid Electric Vehicle (HEV)

(b) Plug-in Hybrid Electric Vehicles (PHEVs)

1. Battery Electric Vehicles (BEV)

These are the vehicles powered by a battery. These batteries can be charged by plugging the vehicle into the charging equipment. Its typical driving ranges from 150 to 300 miles. This type of vehicles do not have an ICE.

2. Hybrid type vehicles

(a) Hybrid Electric Vehicle (HEV)

It has both an Internal Combusion Engine (ICE) and an electric motor. In this type of electric cars, ICE gets energy from fuel while the motor gets electricity from batteries. It offers a mixture of battery and gasoline powers.

The gasoline engine and electric motor simultaneously rotate the transmission, which drives the wheels. Batteries in HEC can only be charged by ICE by the motion of the wheels. The battery cannot be recharged from outside the system.

(b) Plug-in Hybrid Electric Vehicle (PHEV)

This type of electric cars are powered by a conventional fuel (gasoline) and by a rechargeable battery pack. This battery can be charged up with electricity by plugging into an electrical plug. It can also be recharged by ICE.

It operates on electricity until their battery pack is depleted. Once the battery is empty, the engine takes over and the vehicle operates as a conventional non-plug-in hybrid (gasoline) vehicle.

(c) Fuel cell Electric vehicles

Fuel cell technology is to generate electricity, which is required to run the vehicle. Here chemical energy of the fuel is converted directly into electric energy. The main advantage of this vehicle is, it generates electricity, required to run their vehicle, on the vehicle itself.

4. Advantages and disadvantages of electric vehicles

Advantages

(i) Electric cars are energy efficient

(ii) It reduces emission.

(iii) Its performance is high and has low maintenance.

(iv) It can be fuelled for very low price.

(v) It is more convenient and easy to recharge.

Disadvantages

(i) Electric cars can travel less distance.

(ii) It takes longer time to refuel (recharge)

(iii) These are more expensive and battery packs may need to be replaced

(iv) Electric fuelling stations are still in the developing stages.

(v) Initial investment is very high.