Types of Electric Vehicles – BEV, HEV, PHEV, and FCEV

This article is meant for explaining different types of electric vehicles, their construction, components, working principle, and features. A type of vehicle, a car, or a bike, or any other, that uses electricity as the source of energy to run is called an electric vehicle.

Today, electric vehicles are becoming one of the most popular modes of transportation because of their sustainability, low operating cost, and eco-friendliness. Traditional vehicles operating on petrol and diesel have very high operating cost and they also pollute the environment due to emissions.

Till date, several different types of electric vehicles have been designed and developed to provide a most economical, eco-friendly, and convenient replacement or supplement of fuel operated traditional vehicles. Before going to discuss about different types of electric vehicles, let us first understand the construction and working of a typical electric vehicle.

What is an Electric Vehicle and Its Construction?

An electric vehicle is a type of vehicle that utilizes electric motors powered by electricity stored in rechargeable storage batteries to operate or rotates its wheels.

Therefore, the rotational mechanical energy required for forwarding the vehicle is produced by electric motors. The required electricity for operating these electric motors is provided by battery packs mounted in the vehicle itself.

The block diagram of a typical electric vehicle is shown in the following diagram.

The different components of the electric vehicle and their functions are described below −

Electric Motors − Electric is used for converting electricity into motion. In other words, electric motors produce mechanical energy that is required for propelling the vehicle.

Battery Packs − In an electric vehicle, rechargeable storage batteries are used to store electricity required for operating electric motors. In practice, the battery packs used in electric vehicles are made up of a number of lithium-ion cells. The distance range per charge of an electric vehicle is determined from the capacity of the battery pack used.

Electronic Controller − It is an electronic device used for controlling and monitoring the operation of control system of the electric vehicle. The primary function of the electric vehicle’s controller is to regulate the flow of electric energy from the battery pack to the electric motors in response to the pressure applied on the accelerator paddle.

Braking System − In electric vehicles, the regenerative braking system is commonly used. In this braking system, the electric motor act as a generator and converts the mechanical energy back into electrical energy, when brakes are applied. This regenerated electrical energy is stored in the battery packs. This helps in increasing the distance range and overall efficiency of the vehicle.

Battery Charger − In an electric vehicle, an onboard battery charger is provided to recharge the battery pack. This onboard battery charger is plugged into an external source of electricity to charge the vehicle batteries. The onboard charger acts as a rectifier and voltage control device and thus it converts alternating current from the external source into direct current and provide a constant voltage supply to charge the battery pack.

The most significant advantage of electric vehicles is that they do not pollute the environment when operated.

Types of Electric Vehicles

Depending on the technology used and needs of applications, there are several different types of electric vehicles. The four most commonly used types of electric vehicles are given below −

• Battery Electric Vehicle (BEV)

• Hybrid Electric Vehicle (HEV)

• Plug-in Hybrid Electric Vehicle (PHEV)

• Fuel Cell Electric Vehicle (FCEV)

Let us now discuss about each of these types of electric vehicles in detail along with their construction, working, and features.

Battery Electric Vehicle (BEV)

A type of electric vehicle in which only electric motors powered by rechargeable batteries are used is called a battery electric vehicle (BEV). Since, in these electric vehicles, there is no other sources of energy like petrol or diesel and their operation completely relies on electricity. Hence, the battery electric vehicles are also known as All-Electric Vehicles.

The block diagram of a typical battery electric vehicle is shown in the following figure.

From this system architecture of BEV, it can be seen that the following are main components of a battery electric vehicle −

Electric Motor − The electric motor is used to convert electrical energy into mechanical energy required for propelling the vehicle or drive the wheels. In a typical battery electric vehicle, induction motors or permanent magnet synchronous motors are used. The shaft of the electric motor drives the wheels either directly or through a gearbox.

Inverter − It is an electronic circuit that converts direct current from the battery pack into alternating current for operating the electric motors. The inverter also provides the way of changing the voltage and frequency of the alternating current supplied to the electric motor. This is essential for controlling the torque and speed of the motor.

Battery Pack − In battery electric vehicles, an energy storage system consisting of rechargeable batteries is provided to store electrical energy required for operation of the vehicle.

Controller − It is an electronic system that acts as the main processing unit of the vehicle. It monitors and controls the different operations like electric drivetrain functioning, battery charging and discharging, temperature control, communication among different vehicle components, etc. It also regulates the power supply from battery packs to electric motor to improve the performance and efficiency of the vehicle.

Drivetrain − It is a component that transmits the mechanical power from the electric motor to the wheels of the vehicle and rotates them. In the case of battery electric vehicles, the drivetrain consists of an electric motor and a gearbox (some BEVs do not use a gearbox).

Working of Battery Electric Vehicle

In a battery electric vehicle, the electric energy is supplied from battery pack to the electric motor through an inverter. The inverter converts the direct current electricity of battery into alternating current electricity.

When driver presses the accelerator paddle, an electric signal is sent to the controller of the vehicle. The controller gives instruction to the inverter to regulate the voltage or frequency of the alternating current electricity to adjust the speed of the motor and hence the speed of the vehicle. The motor shaft is connected to wheels of the vehicle directly or through a gearbox.

In case when the brakes are applied, the electric motor acts as a generator and converts the kinetic energy of the moving vehicle back into electricity. This braking technology is called regenerative braking. The regenerated electrical energy is utilized to recharge the battery pack. This is how a battery electric vehicle typically works.

Features of Battery Electric Vehicle

The following some important features of battery electric vehicles (BEVs) −

• In battery electric vehicles, there is no combustion of fossil fuels. Thus, they do not pollute the environment.

• The cost of electricity is lower than the cost of fossil fuels like diesel and petrol. Thus, the operating cost of battery electric vehicles is comparatively lower than internal combustion engine vehicles.

• The maintenance cost of battery electric vehicles is also less than ICE vehicle, because they have less number of moving components.

• Electric motors produce less noise when operating as compared to internal combustion engines. Thus, the battery electric vehicles have relatively quiet operation.

• Battery electric vehicles are best option for heavy traffic conditions that require frequent start and stop. This is because they have quick acceleration and deceleration characteristics.

• Battery electric vehicles are more energy efficient, as they use regenerative braking system to recover energy during braking period.

This is all about basics, working, and features of battery electric vehicles (BEVs).

Hybrid Electric Vehicle (HEV)

A type of electric vehicle in which both internal combustion engine and electric motor technologies are combinedly used for propelling the vehicle is known as a hybrid electric vehicle (HEV).

Therefore, in hybrid electric vehicles, both fossil fuels and electricity are the source of energy. The ICE and electric motors are operated in a manner that they can optimize the efficiency and performance of the vehicle.

Overall, a hybrid electric vehicle combines the benefits of both ICE vehicle and all-electric vehicle. Thus, these vehicles are mainly known for their high fuel efficiency.

The block diagram of a typical hybrid electric vehicle is shown in the following figure.

It can be seen that the hybrid electric vehicle combines the components of ICE vehicle and electric vehicle. The main components of a hybrid electric vehicle and their functions are explained below −

Engine − In hybrid electric vehicles, an internal combustion engine operated on petrol or diesel is used. This IC engine runs the vehicle in case when the electric motors are not rotating the wheels. It also provides additional power required for different purposes like high-speed driving, heavy acceleration, charging batteries, etc.

Electric Motors − In a hybrid electric vehicle, electric motors are also provided in addition to the IC engine. These electric motors operate by utilizing electrical energy stored in the battery packs. The main purpose these electric motors is to supplement the IC engine in propulsion. The electric motors mainly operate in case of low-speed driving conditions.

Battery Pack with Controller and Inverter − The battery pack is provided in a hybrid electric vehicle to store the electrical energy required for operating the electric motors. A battery controller is used to regulate the charging and discharging current to improve the performance and life span of the battery pack. In the battery circuit, an inverter is connected that converts DC electricity stored in the battery pack into AC electricity before supplying it to the electric motors.

Fuel Tank − Since, the hybrid electric vehicle has an IC engine. Therefore, a fuel tank is also installed in the vehicle to store petrol or diesel for operating the IC engine.

Control Unit− In hybrid electric vehicles, a centralized electronic circuit called control unit is provided that monitors and controls the different operations of the vehicle such as switching between IC engine and electric motors, charging and discharging of battery pack, and auxiliary systems.

Working of Hybrid Electric Vehicle −

The working of a hybrid electric vehicle (HEV) involves an integrated operation of both the IC engine and electric motors. This combined operation helps to improve the fuel efficiency and performance of the vehicle.

The complete working of a typical hybrid electric vehicle in different conditions is explained below −

Low-Speed Driving Condition − In this condition, the hybrid electric vehicle is propelled by the electric motors powered by the electricity stored in the battery pack. It is because at low driving speeds, a low acceleration is required that can be easily provided by the electric motors more efficiently. Thus, in the low-speed operating conditions, the IC engine is not engaged in the propulsion of the hybrid electric vehicle.

High-Speed and Heavy Acceleration Driving Condition − This condition arises when the vehicle climb a slope or hill or runs on a highway or expressway. In this condition, a large amount power to pull the vehicle is required. Thus, both the internal combustion engine and the electric motors operate together and provide sufficient power required for the propulsion. In this condition, the main power is provided by the internal combustion engine and the power produced by the electric motors supplement it.

Braking and Deceleration Condition − In this operating condition, the electric motors behave like the generators and convert the motion energy into electricity which is then stored in the battery pack for later use.

Features of Hybrid Electric Vehicle

The main features and characteristics of the hybrid electric vehicles are listed below −

• Hybrid electric vehicles are better in terms of performance and fuel efficiency.

• Hybrid electric vehicles do not use IC engine all the times. Thus, they also help in reducing the greenhouse gas emission and environment pollution.

• Hybrid electric vehicles provide a smooth acceleration under different driving conditions. This is accomplished with the help of a complex control mechanism.

• Hybrid electric vehicles have a longer driving range.

• Hybrid electric vehicles do not need to be recharged on a charging station. Instead, they are recharged by IC engine and electric motors during operation.

Thus, this is all about basics, working, and features of hybrid electric vehicles (HEVs).

Plug-In Hybrid Electric Vehicle (PHEV)

The plug-in hybrid electric vehicle or PHEV is an advanced version of hybrid electric vehicle (HEV). Thus, its construction is almost similar to the hybrid electric vehicle, but it consists of a charger for recharging the battery pack by plugging into an external power supply.

Thus, we can describe a plug-in hybrid electric vehicle as a hybrid electric vehicle with an external charging system.

Another major point that differentiates a plug-in hybrid electric vehicle from a normal hybrid electric vehicle is that it can run in any of the following two modes −

• All electric mode − Only electric motors provide the propulsion power to the vehicle.

• Hybrid mode − Both IC engine and electric motor pull the vehicle.

The block diagram of a typical plug-in hybrid electric vehicle (PHEV) is shown in the following figure.

The different components and their functions of a plug-in hybrid electric vehicle are explained below −

Electric Motors − In a plug-in hybrid electric vehicle, the electric motors are used to provide propulsion power when it is operated in all electric mode.

Engine − A petrol or diesel internal combustion engine (ICE) is also provided that rotates the wheels of the PHEV when it is operated in the hybrid mode.

Battery Pack with an Inverter − The battery pack is provided to store electrical energy required for operating the electric motors. The inverter is connected between the battery pack and motors to convert the DC electricity from battery into AC electricity needed for operating electric motors. The battery pack can be recharged by plugging into an external source of electricity.

Fuel Tank − The fuel tank is provided to store the diesel or petrol for fueling up the internal combustion engine.

Control Unit − It is an electronic system that controls and manages the different operations of the plug-in hybrid electric vehicle.

Battery Charger − In plug-in hybrid electric vehicles, a battery charger (onboard or external) is provided to recharge the battery pack by receiving electrical energy from external source of power.

Working of Plug-In Hybrid Electric Vehicle

The working of a typical plug-in hybrid electric vehicle in different modes is explained in below −

All-Electric Mode − In the all-electric mode, the PHEV uses the electricity stored in the battery pack to operate the electric motors. These electric motors propel the vehicle forward. In this mode, there is no fuel consumption. Thus, the vehicle operates silently and do not produce any kind of emission.

Hybrid Mode − Once the battery pack has been fully discharged, the controller automatically switches the vehicle from all-electric mode to the hybrid mode. In this mode, both the IC engine and the electric motors operate together to propel the vehicle.

Features of Plug-In Hybrid Electric Vehicle

Some of the important features of the plug-in hybrid electric vehicles are listed below −

• When PHEVs operate in the all-electric mode, they doe not cause noise and pollution.

• PHEVs can operate in hybrid mode. In this mode, they can provide heavy acceleration and high speeds.

• In hybrid mode, the PHEVs can provide longer distance range.

• Regenerative braking system is used in PHEVs that recharges the battery pack by utilizing the kinetic energy of vehicle during braking or deceleration period.

• PHEVs also support external charging.

• PHEVs have higher efficiency. Consequently, they consume less fuel.

This is all about plug-in hybrid electric vehicle (PHEV), its working and features.

Fuel Cell Electric Vehicle (FCEV)

A type of electric vehicle in which fuel cell technology is used for generating electricity to power up the electric motors and propel the vehicle is called a fuel cell electric vehicle (FCEV).

In FCEVs, high pressure hydrogen gas is used as the fuel. It is stored in a leakproof storage tank. This hydrogen gas is fed from the storage tank into fuel cells where it reacts with oxygen to produce electricity and water vapors. This generated electricity is then utilized for operating electric motors.

The fuel cell electric vehicles are also known as zero-emission vehicles because they do produce any kind of emission.

The block diagram of a typical fuel cell electric vehicle is shown in the following figure.

The main components of a fuel cell electric vehicle are explained as follows −

Electric Motors − In FCEVs, electric motors are used to convert electricity into mechanical energy which is then used for rotating wheels of the vehicle.

Fuel Cell Stack − In a fuel cell electric vehicle, the fuel cell stack is nothing but a collection of fuel cells. It provides an environment for chemical reaction to occur between hydrogen gas and oxygen to produce electricity.

Hydrogen Storage Tank − Hydrogen gas is used as the fuel for generating electricity in a fuel cell electric vehicle. It is stored in a high-pressure storage tank, called hydrogen storage tank.

Battery Pack with Converter and Controller − In fuel cell electric vehicles, an additional small battery pack is provided to store the electricity generated by regenerative braking. This battery pack is then used to provide power during high-demand conditions. The converter is provided to convert the DC into AC and vice-versa. Whereas, the controller is employed for regulating the flow of electricity between the battery pack and components of the vehicle.

Working of Fuel Cell Electric Vehicle

The working of fuel cell electric vehicle is quite straight forward. In these vehicles, the hydrogen gas is fed into a fuel cell stack where it reacts with oxygen of air and produces electricity, heat, and water vapors. The electricity generated is utilized for powering up the electric motors of the vehicle.

Features of Fuel Cell Electric Vehicle

The following are some key features and characteristics of fuel cell electric vehicles −

• The byproduct of hydrogen gas combustion is water vapors. Thus, the fuel cell electric vehicles cause zero emission and hence do not pollute the environment.

• Fuel cell electric vehicles have onboard electricity generation mechanism. Thus, they provide longer driving ranges.

• The refueling time of hydrogen gas is almost equal to the refueling time of petrol or diesel, which is very quick.

• The hydrogen gas is used as the fuel in FCEVs which is generally obtained from renewable and low-carbon sources. Hence, these vehicles help in reducing environmental pollution.

• Fuel cell electric vehicle are highly fuel/energy efficient.

• Fuel cell electric vehicles have silent operation.

This is all about fuel cell electric vehicles and their features.

Conclusion

Electric vehicles are the types of vehicles that use electric motors as the source of propulsion. Some common types of electric vehicles include battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles. All these vehicles are explained above in this article along with their working and features.

FAQs Related to Types of Electric Vehicles

1. What are the 3 main types of electric vehicles?

The following 3 are the main types of electric vehicles commonly used for transportation −

• Battery Electric Vehicle (BEV)

• Hybrid Electric Vehicle (HEV)

• Plug-In Hybrid Electric Vehicle (PHEV)

2. What is the full form of EV?

In context of vehicles, EV stands for Electric Vehicle. A type of vehicle, two-wheeler/three-wheeler/four-wheeler, etc. that uses electricity as the source of energy.

3. What are the types of EV batteries?

The following are the main types of batteries used in electric vehicles (EVs) −

• Lithium-Ion Batteries

• Nickel Metal Hydride Batteries

• Lead-Acid Batteries

4. How do EV vehicles work?

In an electric vehicle, a battery is provided to store the electricity. This electricity is used to power electric motors used in the vehicle. The mechanical energy generated by the motors is then used to rotate the wheels and propel the vehicle.

5. What is the difference between EV and HEV?

Ans − An EV is a purely electric vehicle in which battery powered electric motors are used for propulsion. On the other hand, HEV is a combination of electric vehicle and traditional IC engine vehicle. In an HEV, both electric motors and internal combustion engine are used to propel the vehicle.