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Friday, September 6, 2019

Electric Vehicles Essay Example for Free

Electric Vehicles Essay Skyrocketing fuel pricing along with depleting oil resources and increased environmental concerns have pushed mankind to consider alternative sources of fuel to power automobiles. Among all the alternate fuel ideas that include everything from excreta to biodiesel, electricity has also been considered as a best alternative to conventional fuels. Electric Vehicles (EVs) are a promising technology for drastically reducing the environmental burden of road transport. Electric Vehicles (EVs) have been around since mid 1800s. During early years, electric vehicles had many advantages over cars powered by internal combustion engines. Such as vehicles with internal combustion engines were started using a hand crank, whereas EVs could be started like regular cars today. EVs did not have gearboxes or the noise and vibration levels of a petrol-powered car. However, their expensive price tag and limited range led petrol powered car to prosper. However later, rising fuel prices, limited oil resources and environmental concerns brought the electric car back into mainstream production line for automobiles. Today, almost all mainstream car makers have been building electric concept cars as well as production version of electric and hybrid cars. Introduction: An automobile that is powered entirely or partially by electricity are electric vehicles. Electric cars are the cleanest, most efficient, and most cost-effective form of transportation around. Seriously, electric cars are high-performance vehicles that will continue to meet new challenges in the future. There are generally of three types: Battery Electric Vehicle: A battery electric vehicle runs entirely on an electric motor, powered by a battery. The battery is charged through an electrical outlet. One of it is Nissan Leaf . Plug-In Hybrid Electric Vehicle: A plug-in hybrid vehicle has both an electric motor and a gasoline engine onboard. These vehicles generally run on the electric motor until the battery is depleted, at which point the gas engine can kick in, extending the car’s range. The main battery in a plug-in hybrid is charged through an electrical outlet. An example of a plug-in hybrid is the Chevrolet Volt. Hybrid Electric Vehicle: A typical hybrid electric vehicle is fuelled by gasoline and uses a battery-powered motor to improve efficiency, thus is not considered a plug-in electric vehicle. The battery in a gasoline hybrid is never plugged into an electrical outlet, but instead is powered by a combination of the gasoline engine and regenerative braking. The most well known hybrid electric vehicle is the Toyota Prius. WORKING OF ELECTRIC VEHICLES: A. Battery Electric Vehicles(BEV’s) Electric cars are zero-emission cars at the point of their usage. There are two types of charger plugs in BEV’s. One is quick charger plug which charges the battery at faster rate compared to the household charger plugs. On board chargers are used to convert AC power to DC power. The controller controls the amount of power to be transmitted to the motor, which in turn, converts the electrical power to the motive power. Nickel-Metal Hydride and Lithium-ion cells are the latest battery modes used nowadays. B. Hybrid Electric Vehicles Hybrid electric vehicles combines the best features of conventional as well as electrical cars. The underlying principle of hybrid cars comprises of the usage of temporary power storage which later on enables the major engine to be functioned at the close to its supreme efficiency. There are two types of hybrid drive generated series hybrids and parallel hybrids. In ‘series hybrid’, the combustion engine sends the power to the electrical generator. Electrical generator converts the mechanical energy into electrical energy which is converted into DC by the inverter to be stored in the battery. Power from the battery can be inverted back to AC so that the electric motor converts it into motive power. In parallel hybrid the car wheels are either powered by engine or from the battery powered electric drive-train. Planetary gear system is used to transmit the power into axle. Electric motors and planetary gear system work as a Continuously Variable Transmission(CVT). In both the hybrids, whenever the engine ignites slowly, the excess energy is stored for the later usage. In this way, these cars provide less emission and improved fuel economy. Conventional Cars Vs Electric Vehicles A. Fuel Efficiency In a conventional car: . * 87. 4 % of fuel energy is wasted * Only 12. 6 % of fuel energy is transferred to the wheels * 5. 8 % is turned to kinetic energy, consumed in the brake * 17. 2 % idling losses, engine on with no torque How Hybrids save fuel? 1. Engine is turned off at: -Stops -Lower speed (say less that 15 km/h), an electric motor drives the car until speed reaches a certain limit, then engine kicks in -When vehicle is stopping or going downhill, engine is turned off, and regenerative braking is applied. 2. When engine operates in an inefficient mode(e. g. at very high or very low engine speeds), the electric motor kicks in and assists engine. Engine is driven to its optimum operating zone 3. Engine can be made smaller, due to electric motor assistance B. Emissions: 1. In combustion engine, emissions occur during driving 2. In E-cars, emission occurs only during electricity production. C. Operating Cost 1. In combustion cars, take petrol at Rs. 73/lt, and a car that achieves 25kms/lt. Energy cost is Rs3/km. 2. Now take electricity at Rs. 6/kW-h, and a car that consumes 125 W-h/km. Energy cost is Rs. 0. 75/km D. Efficiency ratio: 1 Combustion engine: 25-30 percent 2. Electric motor: close to 90 percent TECHNOLOGICAL CHALLENGES AND OPPORTUNITIES: The main problem with the electric car is battery. Such as:- Time of battery charging is long. -Batteries are heavy. -Batteries are expensive. -Low performance in hot or cold temperatures also may damage the battery -Very sensitive to overcharge/undercharge(Battery life reduces dramatically) -Contain toxic heavy metals, disposal issue. All these provide scope for the further research and development in the field of electric vehicles. The RD are supported by the government and industries. POSSIBLE FUTURE TECHNOLOGIES: Over population and limited energy resources have pushed the need and the demand of the electric vehicles. In the future, we will have hybrids and battery electric vehicles everywhere in the markets, industries and highways. Some of the possible future technologies in this field are: 1. A photovoltaics-carport (solar service station) which is considered as a charging station of electric cars for the future. 2. Battery recharging which will employ a special chemical process, occurring on all energy-storage particles at once; in contrast to the traditional batteries, where only a fraction of the energy storage can be replenished at once . 3. Electrical outlet and electric cable will not be required in future anymore, because the electric car of the future refuels its power fully automatically and without contacting by induction while driving or parking. CONCLUSION: Electric vehicles (EVs) hold the potential of transforming the way the world moves. EVs can increase energy security by diversifying the fuel mix and decreasing dependence on petroleum, while also reducing emissions of greenhouse gases and other pollutants. Just as important, EVs can unlock innovation and create new advanced industries that spur job growth and enhance economic prosperity. However, the mass deployment of EVs will require transportation systems capable of integrating and fostering this new technology. To accelerate this transitition, cities and metropolitan regions around the world are creating EV-friendly ecosystems and building the foundation for widespread adoption.

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