In 2021, we will witness 108% more sales than in 2020 with 6.75 million EV units being sold out globally. With the increase in popularity of Electric Vehicles, the automobile industry has progressed considerably in the world of electric cars. We now have different types of Electric transport available in the market, powering the vehicle with various sources. Today different models of EVs have diverse ranges, limitations, advantages, and charging methods. To understand the working model of electric cars better we first need to identify them in detail. In today’s time, electric cars are classified into four different types.
Battery Electric Cars (BEV)
Battery electric vehicles, have no gas engines and are pure electric cars. Battery Electric Cars have an approximate range of 160-590 km and do not support any kind of Internal Combustion Engine (ICE). These cars are fully powered by rechargeable battery packs thus having no alternative source. A few main components of BEV are the electric motors for propulsion, Inverter, a high-voltage battery, and a control module to manage the power electronics. Battery Electric Cars tend to use inverters to convert DC into AC to supply it to the motor.
The working of electric cars depends on the signal that is sent to the controller every time driver presses the accelerator. This changes the frequency of the alternating current (AC) from the inverter to the motor causing the turning of the wheels. If the driver applies brakes to adjust the speed, the motor acts as an alternator, thus sending back produced power to the battery. Even if the driver doesn’t accelerate or decelerate the car the battery still receives the power generated from the motor. The use of AC motors can be witnessed in Tata MG, BMW, and Audi’s Battery Electric Car. However, on a contrary, companies like Tesla, Nissan, and Chevrolet are using DC motors in some of their models instead of AC motors.
In present times BEV is a little on the expensive side for many buyers. With limitations like battery life concerns, BEV is considered to have a limited range and poor charging infrastructure. Although in recent times, many top electric car companies have worked on eliminating these concerts. Today the majority of BEVs support fast charging using Level 2 charging at a charging station or can be charged at home. Battery Electric Cars are extremely quiet and have zero emissions when driving. BEV holds a reputation of being “easy and fun to drive”. The car has great acceleration and an excellent single ratio gearbox. The low maintenance cost makes it a budget-friendly buy. BEVs compared to petrol/ diesel cars are cheap to run and tax-efficient in some countries.
Hybrid Electric Cars (HEV)
Hybrid Electric Model Cars are designed to run on both, the traditional internal combustion engine and the electric propulsion system. The ICE works on fueling the car and recharging the empty battery through the ‘regenerative braking’ method. These cars do not plug into off-board sources of electricity to recharge. The vehicle captures energy normally lost during braking by using the electric motor as a generator and storing the captured energy in the battery. HEV model electric car consists of Components like Engine, Electric motor, Fuel tank, Control module, and Battery pack with controller & inverter. A few examples of HEVs are Mercedes-Benz S400 BlueHybrid, BMW 1 and 3 series, Honda Civic and Insight Hybrid, and Kia Optima Hybrid.
The working of HEV causes lower Carbon-based emissions making it environment friendly. Less dependence on fossil fuels Hybrid Electric Cars consume less oil than conventional vehicles. Such cars have financial benefits with low maintenance costs. Assistance from an electric motor provides more mileage during long travels for the driver.
Plug-in Hybrid Electric Cars (PHEV)
PHEV (Plug-in Hybrid Electric Vehicle) is Powered by Electric Motor and Combustion Engine to run, similar to Hybrid Electric Vehicle (HEV). The Main Components of PHEV are Battery, Fuel tank, Engine, Inverter, Control module, Electric motor, and Battery Charger. Considered an upgraded and adaptable version of HEV, the PHEV lets the driver charge a vehicle’s battery with electricity rather than gas or fuel. The plug-in charging can provide an average range of 30-60 km. This gives an added advantage, by making use of electricity until the electric car’s battery pack is depleted. Once the energy charge from the motor and battery is exhausted the all-electric mode switches its working to ICE and the car operates as a conventional. An example of this electric car with a PHEV model is the Mitsubishi Outlander PHEV with a total range of 595km of which 54km is the electric range via the battery.
Plug-in hybrid car batteries are recharged through electric motor regenerative braking or by plugging them into an external electric grid. PHEV is said to have higher battery capacity than HEVs and can travel more than 70 miles on electricity alone.
The series plug-in hybrids and Parallel hybrids are two basic plug-in hybrid configurations –
- Series plug-in hybrids: Popularly known as extended-range electric vehicles, use only the electric motor to rotate the wheels, whereas the fuel engine is used to generate electric power. This helps the electric car switch to work as a parallel hybrid when the battery gets exhausted. Thus electric power is generated from fuel to power the motor causing the vehicle to run.
- Parallel hybrid: Also known as, blended plug-in hybrids, this configuration works by connecting the electric motor and engine to the wheels and causing a force that imparts motion. The PHEV model is fuel-efficient in traffic and saves fuel in regular short commutes. Easy to drive the vehicle has zero-emission when going on batteries. With a significantly lower carbon footprint, PHEVs cost approximately $4,000 to $8,000 in countries like the USA.
Fuel Cell Electric Cars (FCEV)
Fuel Cell Electric Vehicle power EVs using compressed hydrogen gas that is produced by utilising fuel cell technology. Valued in the market at USD 1 billion in 2020 the estimated growth of FCEV is over 40% CAGR between 2021 and 2027. Hydrogen fuel cell units have proved to have an extremely rapid charge time among all EV types. Some major industry giants like Audi AG, Volkswagen, and Hyundai Motor Group, are now working to build a sustainable future with FCEV technology FCEVs are Zero-Emission Vehicles that are fueled by hydrogen gas Unlike other electric cars, model FCEVs do, not require to be plugged into an external electricity grid to recharge.
A few main components of FCEV are a Hydrogen storage tank, Fuel-cell stack, Electric motor, controller, and battery with converter. This hydrogen fuel is stored under pressure in a storage tank in the vehicle itself. It produces electricity for the car to run by using oxygen taken from the air. Sometimes fuel cells are used to power its on-board electric motor using them with a small battery or supercapacitor. The stored energy depends on the amount of hydrogen and the size of the fuel tank. The fuel’s chemical energy is converted to generate the electricity required to run an electric vehicle.
Polymer electrolyte membrane (PEM) is the most common fuel cell for vehicle applications. Between the cathode (positive electrode) and anode (negative electrode), there is an electrolyte membrane in the PEM fuel cell. Oxygen from the air is brought in contact with the cathode and hydrogen from the storage tank is introduced to the anode. The electrochemical reaction takes place in the fuel cell catalyst. In this process, the hydrogen molecules are broken down into protons and electrons. The proton here then moves from the membrane to the cathode. Here the electrons provide power to the EV by travelling through an external circuit and then joining the proton. This happens in the cathode, where water is formed by combining electrons, protons, and oxygen.
Fuel Cell Electric Cars are the most superior type of EV. It provides the driver with the same range as the ICE-powered vehicle (approximately 300 miles). This quality has led it to become the ‘range-extenders’ with fuel cell power units. In present times, the most important concern with adopting FCEV is the highly flammable characteristic of hydrogen fuel. Although like other EVs, the outside temperature does not significantly affect Hydrogen fuel cells, hence not deteriorating in cold weather. The per-unit cost of the hydrogen fuel cell is greater than other energy sources. With the advancement in automobile technology, the cost structure is sure to find a considerable solution.