Extras din referat
An electric car is an automobile that is propelled by one or more electric motors, using energy stored in rechargeable batteries.
Since 2008, a renaissance in electric vehicle manufacturing occurred due to advances in batteries, concerns about increasing oil prices, and the desire to reduce pollution. Several national and local governments have established tax credits, subsidies, and other incentives to promote the introduction and now adoption in the mass market of new electric vehicles depending on battery size and their all-electric range. Compared with cars with internal combustion (IC) engines, electric cars are quieter and have no tailpipe emissions. When recharged by low-emission electrical power sources, electric vehicles can reduce greenhouse gas emissions compared to IC engines.
Thomas Parker built the first practical production electric car in London in 1884, using his own specially designed high-capacity rechargeable batteries. The Flocken Elektrowagen of 1888 was designed by German inventor Andreas Flocken. Electric cars were among the preferred methods for automobile propulsion in the late 19th century and early 20th century, providing a level of comfort and ease of operation that could not be achieved by the gasoline cars of the time. The electric vehicle stock peaked at approximately 30,000 vehicles at the turn of the 20th century.
Advances in internal combustion engines in the first decade of the 20th century lessened the relative advantages of the electric car. The greater range of gasoline cars, and their much quicker refueling times, made them more popular and encouraged a rapid expansion of petroleum infrastructure, making gasoline easy to find, but what proved decisive was the introduction in 1912 of the electric starter motor which replaced other, often laborious, methods of starting the ICE, such as hand-cranking.
California electric automaker Tesla Motors began development in 2004 on what would become the Tesla Roadster (2008), which was first delivered to customers in 2008. The Roadster was the first highway legal serial production all-electric car to use lithium-ion battery cells, and the first production all-electric car to travel more than 320 km (200 miles) per charge.
Electric cars have several benefits over conventional internal combustion engine automobiles, including a significant reduction of local air pollution, especially in cities, as they do not emit harmful tailpipe pollutants. The clean air benefit may only be local because, depending on the source of the electricity used to recharge the batteries, air pollutant emissions may be shifted to the location of the generation plants.
Electric motors can provide high power-to-weight ratios, and batteries can be designed to supply the large currents to support these motors. Electric motors have very flat torque curves down to zero speed. Although some electric vehicles have very small motors, 15 kW (20 hp) or less and therefore have modest acceleration, many electric cars have large motors and brisk acceleration. In addition, the relatively constant torque of an electric motor, even at very low speeds tends to increase the acceleration performance of an electric vehicle relative to that of the same rated motor power internal combustion engine.
Preview document
Conținut arhivă zip
- Electric cars.pdf