Full hybrid, micro-hybrid, parallel, serial or power derived configuration…It is sometimes difficult to find a way around the different technologies offered by electrified vehicles.
Yet, with the ever-increasing growth in Hybrid car purchases, the sector has never been more dynamic, including financial incentives and state-of-the-art models.
In order to better choose your hybrid motor car, here are the basics of the operation of each one
The Hybrid Car: the combination of two engines
A hybrid car (HEV) is based on the combination of an internal combustion engine (gasoline or diesel thermal engine) and one or more electric motors that use energy stored in batteries. These engines can operate jointly or alternately.
This combination allows to take advantage of the advantages of each type of energy while limiting the disadvantages. This saves fuel and reduces exhaust emissions without sacrificing performance.
Hybrid motorization systems can save fuel by stopping the thermal engine when the vehicle is in parking, idling at a traffic stop or when the electric motor’s energy is sufficient to power the vehicle without the assistance of the thermal engine. The battery also provides energy to the air conditioner and accessories while the vehicle is idling. If necessary, the thermal engine reengages to provide more power for acceleration.
Regenerative braking system: at the heart of the hybrid
If the operation differs depending on the nature of the hybridization, all HEV hybrid cars have in common the ability to generate electric current, store it in a battery (different from the conventional 12 V battery) and use this current to help train the wheels.
This capacity to generate electricity is achieved through regenerative braking, which is a mechanism for energy recovery during the deceleration phases: when the driver brakes, the system recovers the heat generated by braking, which would otherwise be lost, and turns it into electricity that it stores in a battery.
Did you know?
Hybrid motorization appeared more than a century ago.
The first hybrid motor car was developed in 1899 by the American Henri Pieper. The following year, Ferdinand Porsche launched a hybrid series that won two speed records. But it was only in the late 1990s that hybrid motorization was truly marketed to the general public
Different engine configurations possible for a hybrid car
Automotive manufacturers use different hybrid designs to achieve various objectives
Hybrid car with parallel hybridization
This is the most common hybrid type. In a parallel hybrid configuration, the electric motor(s) and the thermal engine(s) are connected to a common transmission that combines the two energy sources. This transmission can be automatic, manual or continuous variation (CVT). Because these two energy sources are connected to the powertrain, they are said to be operating in parallel.
The type of transmission and the power of the thermal engine are the main factors that determine the behavior of the parallel hybrid (starting, accelerating, etc.). In general, parallel hybridization makes it possible to operate both types of engines according to the speed at which the vehicle travels. Most often, up to 30 to 50 km/h, the electric motor drives the axle. Beyond that, the thermal engine takes over.
Hybrid car with serial hybridization
In this design, the electric motor(s) are the only ones that provide the driving force to the wheels. Since the thermal engine is not connected to the wheels, its only function is to charge the battery of the electric motor.
For example, the thermal engine can send the electrical current directly to the electric motor or charge the battery that stores the electricity. The electric motor propels the vehicle, using its power to operate a transmission shaft or a set of motor axles that run the wheels.
This hybridization solution is quite rare. The thermal engine operates like a generator that generates the electricity required by the electric motor to move the vehicle forward. However, this results in a more representative driving experience of an electric car, with a softer and more powerful acceleration.
Hybrid Car with Mixed or Power-Derived Hybridization
This type of power-derived hybridization is a combination of the previous two. It allows the thermal engine to deliver power to the axle while driving a generator that recharges the battery, which feeds an electric motor. This architecture offers the possibility of 100% electric operation, but part of the power of the thermal engine is always turned into electricity to recharge the battery or to power the electric motor.
Different operation by hybridization levels
Mixed hybrid car (mild hybrid)
Soft hybridization, also known as mild hybridization or micro-hybridization, uses a small 48V lithium-ion battery and alternno-starter to support the heat engine in order to save fuel, increase performance, or both.
However, the micro-hybridization system cannot propel the car using only electricity. The electric block is only used as a starter for the automatic Start & Stop system, which cuts the engine when the car stops to save fuel, such as in traffic jams or traffic lights. On some light-hybridized car models, the electric motor can also help the thermal engine maintain a constant speed of up to 120 km/h.
While considered a simpler and cheaper way to market hybrid technology, since all conventional vehicle models can be equipped with hybrid technology, micro-hybrid systems do not improve fuel consumption as much as full hybrid systems. The model economy is about 0.5 L/100 km compared to a conventional thermal vehicle.
Full hybrid car
Full hybrid systems use the electric motor as the sole source of propulsion for low speed driving and low accelerations. This electric mode can still increase energy efficiency under certain driving conditions.
A full hybrid car also has a diesel or petrol engine as the main source of power for higher speeds, which generally engages above 50 km/h. The electric motor provides additional power when needed to enable the vehicle to be more efficient with a less powerful diesel or gasoline engine. A hybrid car saves more than 30% of city fuel compared to the same vehicle with a single fossil fuel engine.
Rechargeable Hybrid Car (PHEV)
Unlike HEV hybrid vehicles, whose electricity is generated only by regenerative braking, plug-in hybrid cars, or PHEV (Plug-in Hybrid Electric Vehicle), offer the possibility of being charged also on a household electrical outlet or on a public terminal. By this characteristic, they are halfway between conventional HEV hybrids and fully electric vehicles.
Although they have a thermal engine, rechargeable hybrid cars also have batteries of greater capacity than ordinary hybrids and can therefore travel longer distances in 100% electric mode, up to 60 kilometers for some models (WLTP cycle), such as the Peugeot 3008 Hybrid4 300. A rechargeable hybrid car allows you to make daily trips without requiring the heat engine, simply through the household recharge or on a terminal.