PHEV (Plug In Hybrid Electric Vehicle)

A hybrid vehicle that combines an internal combustion engine and an electric motor, both fueled by a sizable rechargeable battery, is known as a plug-in hybrid electric vehicle (PHEV). The battery can be charged via regenerative braking, the engine, or an external power source like a wall outlet or charging station. PHEVs can operate in gasoline, electric, or a combination of both modes, based on the battery level and driving circumstances. 

Compared to conventional cars, plug-in hybrid electric vehicles (PHEVs) have a number of benefits, including reduced air pollution, fuel consumption, and greenhouse gas emissions. PHEVs do, however, have certain drawbacks, including more expensive, complicated, and heavy componentry as well as a reliance on availability and affordability of the charging infrastructure.

The history of plug-in hybrid electric vehicles (PHEVs) begins in the late 19th and early 20th centuries, when innovators and manufacturers like Thomas Edison, Ferdinand Porsche, and Henri Pieper experimented with different electric and hybrid vehicle prototypes. 

However, the popularity of gasoline-powered cars, advancements in battery technology, and the lack of environmental concerns caused interest in plug-in hybrid electric vehicles to wane. With the development of battery technology, the rise of environmental concerns, and the backing of government policies and incentives, the modern era of plug-in hybrid electric vehicles (PHEVs) began in the late 20th and early 21st centuries.

Components of hybrid vehicles

The main components of a hybrid vehicle are:

• ICE: This is the device that converts the chemical energy of the fuel into mechanical energy, and drives the wheels or the generator of the vehicle. ICEs are the most common and widely available power source for vehicles, and can use different types of fuels, such as gasoline, diesel, ethanol, or biodiesel. ICEs have a high power density, a long range, and a fast refueling time. However, ICEs have a low efficiency, a high emissions, and a high noise level.

• Electric motor: This is the device that converts electrical energy into mechanical energy, and drives the wheels or the generator of the vehicle. Electric motors are more efficient, quieter, and smoother than ICEs, and can provide instant torque and acceleration. Electric motors can be classified into two types: alternating current (AC) motors and direct current (DC) motors. AC motors are more common in hybrid vehicles, as they can be easily controlled by varying the frequency and voltage of the input current. DC motors are simpler and cheaper, but require a controller to convert the AC current from the battery or the charger into DC current.

Read Also : Hybrid Electric Vehicle How It's Work & Components

• Battery: This is the device that stores electrical energy and provides power to the electric motor and other components of the vehicle. Batteries are composed of cells, which are connected in series or parallel to increase the voltage or the capacity. The most common type of battery used in hybrid vehicles is the nickel-metal hydride battery, which has a moderate energy density, a long lifespan, and a high power output. Other types of batteries used in hybrid vehicles are lead-acid, lithium-ion, and nickel-cadmium batteries, which have different performance and environmental impact.

• Fuel cell: This is the device that produces electrical energy from a chemical reaction between hydrogen and oxygen. Fuel cells consist of an anode, a cathode, and an electrolyte, which allow the flow of ions and electrons. Hydrogen is supplied to the anode, where it is split into protons and electrons. The protons pass through the electrolyte to the cathode, where they react with oxygen to form water. The electrons flow through an external circuit to the cathode, creating an electric current. Fuel cells have a high efficiency, low emissions, and long range, but they are very costly, complex, and sensitive to temperature and humidity.

• Solar panel: This is the device that converts the solar energy into electrical energy, and provides power to the battery or the supercapacitor of the vehicle. Solar panels are composed of photovoltaic cells, which are made of semiconductor materials, such as silicon, that generate electricity when exposed to light. Solar panels have a renewable and clean energy source, and can reduce the fuel consumption and the emissions of hybrid vehicles. However, solar panels have a low efficiency, a high initial cost, and a variable and intermittent power output, depending on the weather and the time of the day.

• Supercapacitor: This is the device that stores electrical energy and provides power to the electric motor and other components of the vehicle. Supercapacitors are composed of electrodes, which are separated by an electrolyte, and store energy by accumulating electric charges on the surface of the electrodes. Supercapacitors have a very high power density, a very fast charging and discharging time, and a very long lifespan. However, supercapacitors have a very low energy density, a very high self-discharge rate, and a very high cost.

• Charger: This is the device that converts the AC current from the grid or a generator into DC current that can be used to charge the battery or the supercapacitor of the vehicle. Chargers can be classified into three levels, depending on the power and the speed of charging. Level 1 chargers use a standard 120-volt outlet and can charge a typical hybrid vehicle in 8 to 12 hours. Level 2 chargers use a 240-volt outlet and can charge a typical hybrid vehicle in 4 to 6 hours. Level 3 chargers use a 480-volt outlet and can charge a typical hybrid vehicle in 30 to 60 minutes. However, level 3 chargers are more expensive, less available, and can degrade the battery life if used frequently.

• Controller: This is the device that regulates the power and the speed of the electric motor, based on the input from the accelerator pedal and the battery state of charge. The controller also controls the regenerative braking system, which recovers some of the kinetic energy of the vehicle when braking or coasting, and converts it into electrical energy that can be stored in the battery or the supercapacitor. Regenerative braking can improve the efficiency and the range of hybrid vehicles, as well as reduce the wear and tear of the brakes.

Benefits of hybrid vehicles

Hybrid vehicles have many benefits over conventional vehicles that use only ICEs, such as:

• Lower emissions: Hybrid vehicles produce lower tailpipe emissions, depending on the type and the source of power. This can reduce the greenhouse gas emissions and the air pollution that contribute to climate change and health problems. According to the US Environmental Protection Agency, a typical hybrid vehicle emits about 200 grams of carbon dioxide equivalent per mile, compared to about 400 grams for a typical ICE vehicle.  However, the emissions of hybrid vehicles also depend on the life cycle analysis, which includes the emissions from the production, transportation, and disposal of the vehicle and its components, as well as the emissions from the generation and transmission of electricity.

• Higher efficiency: Hybrid vehicles convert about 40% of the fuel or the electricity into mechanical energy, compared to about 20% for ICE vehicles.  This means that hybrid vehicles use less energy and less fuel to travel the same distance as ICE vehicles. Hybrid vehicles also have lower energy losses from idling, friction, and heat, and can recover some of the energy through regenerative braking.

• Better performance: Hybrid vehicles have a better acceleration, a better torque, and a better handling than ICE vehicles, as they can use the electric motor to assist the ICE at low speeds or when overtaking, and can use the battery or the supercapacitor to provide a power boost. Hybrid vehicles also have a smoother and quieter ride than ICE vehicles, as they can switch off the ICE when not needed, and can use the electric motor to start and stop the vehicle.

• Longer range: Hybrid vehicles have a longer driving range than electric vehicles, as they can use the ICE or the fuel cell to extend the battery or the supercapacitor life. Hybrid vehicles also have a faster refueling time than electric vehicles, as they can use the existing fuel stations or the hydrogen.