Hybrid electric vehicle (HEVs) is the type of electric vehicle which uses both internal combustion engine and electric motor propulsion system. The purpose of this vehicle hybrid electric vehicle is to increase fuel efficiency and increase the drive range of electric vehicle. This hybrid electric vehicles helps to improve emissions by utilizing both internal combustion engine and electric power sources.
Hybrid electric vehicle helps to improve efficiency as there are minimal mechanical part which reduce the friction and hence this helps to improve efficiency of hybrid electric vehicles.
How hybrid electric vehicle work?
Hybrid electric vehicle (HEVs) is the type electric vehicle which uses both internal combustion engine and electric motor propulsion system.
Electric motor and Battery:
As pure electric vehicles hybrid electric vehicle comes with electric motor and high voltage battery packs to store electric power that used to power the electric motor of vehicle.
Internal combustion Engine (ICE)
In hybrid electric vehicle have same internal combustion engine as in conventional vehicles and it is fueled by gasoline. Internal combustion engine is used as required and power wheels. In some cases, the internal combustion engine is used to drive wheels or to charge the vehicle battery pack.
Power control unit (PCU)
The power control unit is computerized control system which manages electric power between battery and electric motor, and it also controls the engagement of internal combustions engine. This computerized control unit helps to optimal use of both electric motor and internal combustion engine.
Regenerative Braking System
As in typical electric vehicle regenerative braking system performs same role that is to convert kinetic energy of wheels into electric energy. During braking or coasting.
The electric motor acts as a generator which converts kinetic energy of wheels into electrical energy this process known as regenerative braking. This energy id used to charge battery pack.
The electric motor acts as a generator which converts kinetic energy of wheels into electrical energy this process known as regenerative braking. This energy id used to charge battery pack.
Automatic Start / Stop System
In hybrid electric vehicle the system is used to utilize power of electric motor and internal combustion engine. When vehicle speed is stop or low-speed operation internal combustion engine is turned off automatically by system. The electric motor takes over for acceleration which helps to reduce fuel consumption and emission in stop-and-go traffic situation.
This improves performance by reducing load on engine.
Parallel and Series Configuration
In hybrid electric vehicle the electric motor and engine are configured parallel and series. In parallel configuration electric motor and internal combustion engine can drive wheels either simultaneously or individually.
In series hybrid electric vehicle, the internal combustions engine is not directly connected to the wheels it is used to drive generator which produce electrical energy used to charge the battery pack.
Power management and optimization
In hybrid electric vehicle, the vehicle is on board with computerized control system which optimize engine power and electric motor power based on driving conditions such as acceleration, speed and loads. This system continuously monitors vehicle drive condition, optimize and ensure that vehicle is operating most efficiently.
Hybrid electric vehicle operates in many hybrid modes such as low-speed mode in which only electric motor supply power to the wheels.
Internal combustion mode for high-speed while driving on highways. Sometimes both used in combination and demanding driving condition.
Types hybrid electric vehicles
- Parallel Hybrid
- Series Hybrid
Parallel Hybrid
In parallel hybrid vehicle it uses both electric motor and internal combustion engine to drive wheels
Parallel hybrid vehicle electric motor and internal combustion engine both are connected to the vehicle transmission and drive wheels at the same time.
Electric motor of parallel hybrid provides power during acceleration as electric motor provides high starting this will helps to get starting torque to vehicle. This will help to reduce starting power required by the internal combustion engine and improves the efficiency of vehicle.
Parallel hybrid vehicle reduce emission in stop-and-go traffic as this used electric regenerative system and electric motor in such situations.
Series Hybrid
In series hybrid vehicle internal combustion engine and electric motor are connected in series which means the internal combustion engine will acts as generator and produce electric power which powers the electric motor.
Series hybrid electric vehicle only electric motor is connected to the wheels and only motor drives the wheels. The advantage of series drive system is that there no direct load in engine and no need of any mechanical transmission systems.
Series hybrid electric vehicles are quite more efficient than parallel electric vehicles. They provide good acceleration and starting torque.
Advantages of hybrid electric vehicle
Hybrid electrics have some key advantages as it combines both internal combustion and electric motor propulsion system.
- Hybrid electric vehicles can achieve higher fuel efficiency than the internal combustion engine by using electric motor during acceleration and at lower speed requirements in stop and go traffic.
- Hybrid electric vehicle uses regenerative braking system which helps to charge battery pack of hybrid electric vehicle. This help to saving of fuels.
- Hybrid using both internal combustion engine and electric motor produces lowers emission as it uses electric power during acceleration, lower speed traffic and idling situations. This reduces greenhouse gases and helps to improve air quality.
- By using electric power in urban areas helps mitigate the environmental impact of stop-and-go traffic.
- Hybrid electric vehicle energy efficiency and optimization system allows the optimal use of internal combustion engine by operating engine it in its most fuel-efficient range. This efficiency is particularly beneficial in highway driving conditions.
- Hybrid electric vehicle have on board computer systems which manages the power distribution between internal combustion engine and electric motor, ensure that the optimal performance based on driving conditions.
- Regenerative generative system helps to improves efficiency by converting kinetic energy into electric energy which charge on board battery pack.
- Hybrid electric vehicles (HEVs) helps to improve drive range more than battery electric vehicle, offers flexibility to operate on both fuel and electric power.
- The internal combustion engine ensures that are not limited by availability of charging stations. Suitable for long distance travel.
- Noise free and environment friendly operations.
- Many governments offer tax benefits and subsidies.
Disadvantages of Hybrid electric vehicles
As hybrid electric have some key advantages, they also come with some disadvantages as follows.
- Hybrid electric vehicle have more initial cost as they equipped with internal combustion engine and electric motor, battery pack and also different computerised control system.
- Hybrid electric vehicle have drive range lower as compared to the plug-in hybrid electric vehicle.
- Hybrid electric vehicle require more maintenance cost as they have internal combustion engine. Also, they have electric motors and battery packs.
- Hybrid electric vehicle more weight than pure typical electric vehicle this affects the performance of electric vehicle.
- Hybrid electric vehicle have more complex powertrain system which involves both traditional engine and Electric components.
- In hybrid electric vehicles uses the high voltage batteries gets degrades over the time which affects vehicle performance and efficiency. Replacement of batteries are costlier, and the disposal recycling of batteries affects environment.