17-09-2014, 11:12 AM
ELECTRICAL VEHICLES
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Introduction
The 1960s and 1970s saw a need for alternative fueled vehicles to reduce the problems of exhaust emissions from internal combustion engines and to reduce the dependency on imported foreign crude oil. During the years from 1960 to the present, many attempts to produce practical electric vehicles occurred and continue to occur.
People choose the electric car for its quiet and comfortable ride over the vibration, smell and high maintenance of gasoline-powered counterpart. Best of all, the electric vehicle (EV) did not require changing gears.
The overall impact of the electric vehicle ultimately benefits the people. Compared to gasoline powered vehicles, electric vehicles are considered to be ninety-seven percent cleaner, producing no tailpipe emissions that can place particulate matter into the air. Particulate matter, carcinogens released into the atmosphere by gas-powered vehicles, “can increase asthma conditions, as well as irritate respiratory systems”
Operation for EV
When the driver steps on the pedal the potentiometer activates and provides the signal that tells the controller how much power it is supposed to deliver. There are two potentiometers for safety. The controller reads the setting of the accelerator pedal from the potentiometers, regulates the power accordingly, takes the power from the batteries and delivers it to the motor. The motor receives the power (voltage) from the controller and uses this power to rotate the transmission. The transmission then turns the wheels and causes the car to move forward or backward.
If the driver floors the accelerator pedal, the controller delivers the full battery voltage to the motor. If the driver takes his/her foot off the accelerator, the controller delivers zero volts to the motor. For any setting in between, the controller chops the battery voltage, thousands of times per second to create an average voltage somewhere between 0 and full battery pack voltage.
Advantages and Disadvantages of the EV
The greatest challenge EVs face deal with the rechargeable battery. Most EVs can only go about 100–200 miles before recharging; fully recharging the battery pack can take four to eight hours. Battery packs are heavy, expensive, may need to be replaced, and take up considerable vehicle space. Overall, the electric vehicle has more advantages than disadvantages. Advantages include no tailpipe emissions, which leads to a reduction in global warming and unhealthy people. Table summarizes the advantages and disadvantages of the EV.
Future of the EV
Future electric cars will most likely carry lithium-ion phosphate (LiFePO4) batteries that are now becoming popular in other countries. The LiFePO4 batteries are rechargeable and powerful and are being used in electric bikes and scooters. Electric cars will most likely adopt this technology in the future.
If the developers of future electric cars can create vehicles with a range of 300 miles per charge, a charging time of five to ten minutes, and safety in operating the vehicles, the market is wide open for them. Researchers are working on improved battery technologies to increase driving range and decrease recharging time, weight, and cost. These factors will ultimately determine the future of Ev’s.