With growing demand for more & more efficient engines in terms of fuel economy and pollutant emissions, the automotive industry is gradually shifting to Hybrid Technology. In simple words, it means there are at least two sources of power for propulsion, the IC engine, and the electric motor.
This method has not only proven to improve fuel economy by a significant level but also reduce the emissions caused by IC engines which include nitrous oxides, particulate matter, greenhouse gases and what not. So why is this so-called “Hybrid Technology” not efficient? Let us find out.
The basic idea is to drive a car to a certain distance without using the engine, but by using a battery to charge the motor which in turn rotates the wheels. But as simple as it sounds, it’s more complicated to implement it in real life. Complications like these can give rise to various kinds of Hybrids.
Types of Hybrids
This is the simplest form of hybrid in which there is only a small lead acid battery and no electric motor. It has a start/stop function in which the battery powers the circuits like the infotainment system, air conditioner, lights etc. When the car is at standstill, the engine is turned off during this period and is turned on when the car has to move. The battery is charged by regenerative braking (i.e. converting the thermal energy produced by the brakes into electrical energy to charge the battery).
Mild hybrids are a step up from Micro Hybrids. In addition to the battery, they have an electric motor which provides initial torque to get the car running before switching it back to the engine. The difference is that Mild hybrids are more focused on fuel economy rather than conventional hybrids, eliminating the sacrifice of gas for acceleration.
The disadvantage is that this kind of hybrid boasts a smaller engine/motor as well as a weaker battery, making the vehicle less powerful. Regardless, it is a good alternative, because you get the main benefits of a hybrid car at a lower cost and weight.
A full hybrid has the main features of a Mild hybrid, but the battery size here is relatively larger. This allows the car to have a pure electric range of 5-10 km which saves even more gas, as the electric motor can be used to power the vehicle. The vehicles accessories such as the A/C, windows and radio are all powered by the battery.
Plug-in hybrids are nearly identical to Full hybrids, but come with larger batteries that are rechargeable using a wall plug and the vehicle is able to drive for more than 25 miles on electricity alone. Pretty innovative huh?
The arrangement of its electric motor, engine and battery system make it so that the vehicle can drive using electricity at low speeds/cruising. HEVs have two such arrangements.
- Series hybrid electric vehicle
- Parallel hybrid electric vehicle
Series Hybrid Electric Vehicle
In the case of a Series Hybrid Electric Vehicle, the propulsion is done only through the electric motor. The ICE, connected to an electric generator, is only used to generate electric energy to power the electric motor or to charge the high voltage battery and does not propel the vehicle directly.
The engine is typically smaller in a Series drivetrain because it only has to meet certain power demands; the battery pack is generally more powerful than the one in Parallel Hybrids in order to provide the remaining power needs. This larger battery and motor, along with the generator, add to the vehicle’s cost, making Series Hybrids more expensive than Parallel Hybrids.
Parallel Hybrid Electric Vehicle
In vehicles with Parallel Hybrid drivetrains, the engine and electric motor work in tandem to generate the power that drives the wheels. Parallel hybrids tend to use a smaller battery pack than Series drivetrains, relying on regenerative braking to keep it recharged. When power demands are low, parallel hybrids also utilize the motor as a generator for supplemental recharging, much like an alternator in conventional cars.
Since the engine is connected directly to the wheels in Parallel drivetrains, the inefficiency of converting mechanical power to electricity and back is eliminated, increasing the efficiency of these hybrids on the highway. This reduces but does not eliminate, the efficiency benefits of having an electric motor and battery in stop-and-go traffic.
Power-split hybrid drivetrain
In addition to Series and Parallel hybrids, there is another hybrid system known as Power-Split Hybrid drivetrain which is the combination of both Series and Parallel hybrid system as seen in Toyota Prius. This system incurs higher costs than a pure parallel hybrid since it requires a generator, a larger battery pack, and more computing power to control the dual system. Yet it can perform better and use less fuel than either the series or parallel systems alone.
All hybrid vehicles offer innovative dual-source powertrains that will progressively introduce improved performance and efficiency statistics. Cutting-edge hybrid technology promises to be prominent in future, as it satisfies consumers that demand better fuel economy as well as those desiring performances. The future of the automobile appears to be promising, as this is just the foundation of hybrid vehicle technology. What are your views on Hybrid Technology, let us know in the comment section below.