Plug-In Hybrid Electric Vehicle (PHEV)

Plug-In Hybrid Electric Vehicle (PHEV) is a vehicle technology that combines the features and advantages of a conventional IC engine-based vehicle and an electric vehicle. The plug-in hybrid vehicles are the important component of a smart grid system.

Here, we will explain the basics of plug-in hybrid vehicle and its significance in smart grid technology.

What is a Plug-In Hybrid Electric Vehicle?

Plug-In Hybrid Electric Vehicle (PHEV) is a type of hybrid electric vehicle that consists of an IC engine and electric motor to propel the vehicle. These vehicles are slightly different from normal hybrid electric vehicles, as they have a large rechargeable battery and are charged by plugging into an external source of power.

The unique combination of electric vehicle technology with the conventional vehicle technology reduces the fuel consumption and emissions in the environment. Also, the plug-in hybrid electric vehicles are charged from a charging station based on renewable energy like solar, wind, etc. Therefore, these vehicles help in building a sustainable energy system.

The block diagram of a typical plug-in hybrid electric vehicle is shown in the following figure −

It consists of the following major components −

• Rechargeable Battery − To store electricity to run the electric motors.
• Electric Motors − To drive the wheels of the vehicle.
• Inverters − To convert batterys DC electricity into AC power to drive the motors.
• Rectifier − To convert AC from external power into DC to recharge the battery.
• Charger − To provide a connection between charging station and vehicles charging port.
• Fuel Tank − To store gasoline or diesel to power internal combustion engine.
• IC Engine − To drive the vehicle over long distances and at high speeds when electric vehicle technology is not suitable.

Significance of PHEV in Smart Grid

In smart grid technology, the plug-in hybrid electric vehicles play an important role for both consumers and electricity companies. The following points highlight this significance −

Demand Response and Load Management

This is one of the major functions that plug-in hybrid electric vehicles perform in smart grids. Under this process, the PHEVs are charged during low demand period and discharged during peak demand periods to supply power back to the grid. This process helps in balancing the supply and demand and reduces need for additional power generation. Thus, PHEVs act as an energy storage system in the smart grid and enables grid operators to manage load demand efficiently.

Renewable Energy Integration and Energy Storage

Plug-in hybrid electric vehicles are charged from renewable energy-based charging stations. The battery used in these vehicles has substantial storage capacity and hence can be used to store extra-energy produced by the renewable energy resources. Therefore, these vehicles also help in integration of renewable energy and energy storage system into the smart grid.

Implementation of Vehicle to Grid Technology

The plug-in hybrid electric vehicles provides bidirectional flow of electric power between vehicle and the grid. Therefore, PHEVs also support in addressing the power outages by providing flow of power from vehicle back to the grid.

Economic Advantages

Plug-in hybrid vehicles also provide several economic benefits like lower operating cost per km, reduced fuel consumption, lower re-filling cost, etc.

Environmental Benefits

The charging of PHEVs is primarily dependent on renewable energy resources. Also, they consume less fuel. Hence, PHEVs emit lower pollutants and greenhouse gases.

Challenges in Integration of PHEVs in Smart Grids

Although plug-in hybrid electric vehicles have several benefits when integrated into the smart grid, but their integration into the smart grids faces various challenges, some of them are listed below −

• The adoption of plug-in hybrid electric vehicles at large scale need a robust and easily accessible charging infrastructure. This requires high investment.
• PHEVs enable bidirectional flow of power between vehicle and grid. Thus, it is required to upgrade our conventional grid with modern technologies and devices to implement this functionality which is again a cost intensive task
• There are lots manufacturers of PHEVs, charging stations, and utility service providers. There may be compatibility issues between all these components due to non-standardization of communication protocols and interfaces.
• For proper optimization of grid operations, we need to manage and process the huge amount data produced by PHEVs and smart grid components. This requires advanced technology and investment.
• In development and deployment of PHEVs in smart grid infrastructure require several certifications from government and regulatory bodies which adds additional processing time.

Conclusion

In conclusion, PHEVs are hybrid electric vehicles that rely on both fossil fuel and electrical energy for their operation. These are called plug-in vehicles because we need to plug them into an external source of supply for charging their battery pack.

PHEVs play a significant role in smart grids as they help in load balancing, renewable energy integration, emergency power supply during outage, reducing dependence on fossil fuel, and building a sustainable, reliable, and efficient electric grid for future.