Electric vehicles rules the future of transportation. There are many reasons of showing interest in these vehicles, one of them was they are environmental friendly which creates less pollution. Any news story about hybrid cars usually talks about electric cars as well.
An electric car is a car powered by an electric motor rather than a gasoline engine. From outside, you would probably have no idea that a car is electric. When you drive an electric car, often the only thing that clues you in to its true nature is the fact that it is nearly silent.
There are a lot of differences between conventional cars and electric cars, The Internal combustion engine is replaced by an electric motor which gets its power from an array of rechargeable batteries.
A combustion engine, with its fuel lines, exhaust pipes, coolant hoses and intake manifold, tends to look like a plumbing project. An electric car is definitely a wiring project.
How It Works:
An electric car is the combination of:
- Electric motor
- DC Controller
- Batteries
The Controller takes power from the batteries and delivers it to the motor. The accelerator pedal hooks to a pair of potentiometers (variable resistors), and these potentiometers provide the signal that tells the controller how much power it is supposed to deliver. The controller can deliver zero power (when the car is stopped) and full power (when the driver press the accelerator pedal).
The signal from the potentiometers tells the controller how much power to deliver to the electric car’s motor. Controller reads the setting of the accelerator pedal from the potentiometers and rapidly switches the power to the motor ON and OFF which powers the wheels. For instance, If you have the accelerator pedal 25 percent pressed, the controller pulses the power so it is ON 25 percent of the time and OFF 75 percent of the time.
Electric Motors:
Electric cars can use DC or AC motors,
- DC motor: It runs from 96V to 192V. These motors have a nice feature that you can overdrive them for short periods of time and deliver 5 times its rated horsepower. The only limitation is heat build-up in the motor. Too much overdriving leads the motor heats up to the point where it self-destructs.
- AC motor: It is probably a three-phase motor running at 240V AC with a 300V battery pack. These motors often have a regenerative braking feature i.e. during braking, the motor turns into a generator and delivers power back to the batteries.
Batteries:
Present, the weak part in any electric car is the batteries. There are four problems in currently used batteries which are,
- Heavy and bulky
- Shorter life Span
- Slow to charge
- Expensive
Many industries are working on this front to introduce Lithium-Ion batteries which overcomes few these problems.
DC-to-DC convertor:
A DC-to-DC converter is normally a separate box under the hood, but sometimes this box is built into the controller. Electric car has a 12-volt battery to power all of the accessories. To keep the battery charged, an electric car needs a DC-to-DC converter. This converter takes in the DC power from the main battery array (say, 300 volts DC) and converts it down to 12 volts to recharge the accessory battery. When the car is ON, the accessories get their power from the DC-to-DC converter. When the car is OFF, they get their power from the 12-volt battery.
Charging an Electric car:
Electric car that uses batteries needs a charging system to recharge the batteries has two goals,
- To pump electricity into the batteries as quickly as the batteries will allow
- To monitor the batteries and avoid damaging them during the charging process
However, there are many technologies getting introduced to reduce the complexity of internals in electric cars. Also there is a scope of converting the conventional type of cars to electric cars which is a dream for many drivers owning a conventional ones.
TECH AUTOMOTIVE 