How Do Plug-In Hybrid Electric Cars Work?

Plug-in hybrid electric vehicles (PHEVs) use batteries to power an electric motor and use another fuel, such as gasoline or diesel, to power an internal combustion engine. PHEV batteries can be charged using a wall outlet or charging station, by the internal combustion engine, or through regenerative braking. The vehicle runs on electric power until the battery is depleted, and then the car automatically switches over to use the internal combustion engine. Learn more about plug-in hybrid electric vehicles.

Key Components of a Plug-In Hybrid Electric Car

Battery (auxiliary): In an electric drive vehicle, the auxiliary battery provides electricity to start the car before the traction battery is engaged and 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: 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 generator: Generates electricity from the rotating wheels while braking, transferring that energy back to the traction battery pack. Some vehicles use motor generators that perform both the drive and regeneration functions.
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.
Exhaust system: Channels the exhaust gases from the engine out through the tailpipe.
Fuel filler: A filler or "nozzle" used to add fuel to the tank.
Fuel tank (gasoline): Stores gasoline on board the vehicle until it's needed by the engine.
Internal combustion engine (spark-ignited): In this configuration, fuel is injected into the intake manifold or combustion chamber and combined with air, and the air/fuel mix is ignited by the spark from a spark plug.
Onboard charger: Takes the incoming AC electricity supplied via the charge port and converts it to DC power for charging the traction battery. It regulates 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: The transmission transfers mechanical power from the engine and/or electric traction motor to drive the wheels.


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