Hybrid Vehicles
Plug-in Hybrid
Electric Vehicle

Plug-in Hybrid

Plug-in Hybrid Electric Vehicles (PHEVs) use batteries to power an electric motor, as well as another fuel, such as diesel, to power an internal combustion engine. PHEVs can charge their batteries through charging equipment and regenerative braking. Unlike Hybrid Electric Vehicles, Plug-in Hybrids have larger battery pack. For example, depending on the model, ranges up to 100 kilometres and more are possible in pure electric mode. Standard fuel consumption of a plug-in hybrid is up to 35% less than that of a comparable ICE vehicle. However, whether this is achieved under real road conditions depends largely on the driver recharging the battery regularly and actually taking advantage of the fuel saving potential. Seasonal fluctuations also have to be taken into account, as lower temperatures reduce the battery range.

Key Components of a Plug-In Hybrid Electric Car

Battery (auxiliary):

Auxiliary battery provides electricity to start the vehicle before the traction battery is engaged and it also powers 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:

DC/DC converter converts higher-voltage DC power from the traction battery pack to the lower-voltage DC power which is required to run vehicle accessories and recharge the auxiliary battery.

Electric generator:

Generates electricity from the rotating wheels while braking, transferring that energy back to traction battery pack.

Electric traction motor:

This motor drives the vehicle’s wheels by using the power from traction battery pack.

Exhaust system:

The exhaust system removes the exhaust gases from the engine out through the tailpipe. A three-way catalyst is designed to reduce engine-out emissions within the exhaust system.

Fuel filler:

A nozzle from a fuel dispenser attaches to the receptacle on the vehicle to fill the tank.

Fuel tank:

This tank stores fuel on board the vehicle until it is required by the engine

Internal Combustion Engine (spark-ignited):

Fuel is injected into either the inlet manifold or the combustion chamber, where it is combined with air, and the air/fuel mixture is ignited by the spark from a spark plug.

Onboard charger:

Onboard charger converts AC 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 controls the speed of the electric traction motor and its torque by managing the flow of electrical energy delivered by the traction battery.

Thermal system (cooling):

This system maintains an optimum 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.


The transmission transfers mechanical power from the engine and/or electric traction motor to drive the wheels.