Basics Of How Hybrid Vehicles Work
Automotive engines that rely solely upon gasoline may one day be a memory, though that day is likely to be many years down the road. Hybrid-electric vehicles (HVs or HEVs) are more efficient and environmentally friendly than their fuel-driven counterparts. They are designed around a configuration that takes advantage of an internal combustion engine (ICE) and an electric motor (EC). In doing so, they yield better fuel efficiency, more power output, and by most owners’ accounts, a quieter ride.
Below, we’ll explore how HVs work. You’ll discover what occurs under the hood that allows these disparate parts to work together. We’ll approach it methodically, beginning with starting the car, cruising, and bringing it to a stop.
Starting And Delivering The Initial Power
With most HEVs, the internal combustion engine does most of work. It delivers the majority of the propulsion power while the electric motor functions as a supplemental source. The motor places resistance on the vehicle’s drivetrain, thereby slowing the wheels. That creates kinetic energy which, in turn, rotates the motor. As the EM rotates, it converts the kinetic energy into an electrical current and stores it in the battery. The electricity remains in the battery until it is required by the motor. This design is called regenerative braking.
When you turn the key in the ignition, the ICE comes to life. If necessary, the EM will retrieve electricity from the battery to provide a secondary power source.
Cruising Down The Road
While you’re driving, a computer is constantly monitoring the performance of your vehicle. Its purpose is to determine your driving conditions, your intent, and ultimately, when it is appropriate to engage the electric motor.
For example, suppose you’re cruising down the road at a normal speed. Because the driver in front of you is moving too slowly, you change lanes and push your accelerator pedal to gain speed. You are essentially placing your engine under a heavier load. The computer identifies your intent and engages the electric motor to deliver a boost of power.
When you begin to cruise along at a normal speed again, the computer switches the EM off in order to conserve energy. By doing this, your car is far more fuel-efficient than would be the case if it were relying solely upon a traditional gasoline engine.
Stopping And Idling
The regenerative braking design mentioned earlier works to slow your wheels and bring your hybrid to a stop. When your vehicle comes to a full stop, the computer switches the engine and the motor off in order to avoid wasting energy while idling. The auxiliary systems (i.e. stereo, power windows, air conditioner, etc.) continue to receive power from the battery.
When you press on the accelerator to resume driving, the computer engages the internal combustion engine to produce the initial propulsion power. It then continues to monitor your hybrid’s performance to determine whether the electric motor should be engaged.
Why Hybrids Are More Fuel Efficient
There are several reasons why HEVs can deliver the same power output as a traditional internal combustion engine with greater fuel economy. First, the computer conserves gas by turning the engine off while idling (described above). Second, the kinetic energy normally wasted while braking is captured by the EM and stored in the battery. Third, hybrids are usually lighter than conventional vehicles, which requires less energy to propel forward. Fourth, most hybrids have been aerodynamically optimized to reduce drag.
This fuel efficiency is a compelling argument for the technology, and has motivated millions of people to buy hybrid vehicles. In fact, as gasoline prices have risen over the past few years, more people than ever are considering the same purchase. Over the next decade, we’ll likely witness a transformation in automotive design as cars, trucks, and even SUVs begin to integrate advanced hybrid technology.