Working Of Electric Cars
Studies have shown that the past decade had a rise in the number of cars to almost 500% than the previous one! This rise in cars has also been a major cause for the vast environmental pollution throughout the world. The introduction of electric cars has proved that they are very much environmental friendly and less pollute compared to gas cars. There has been a rapid increase in the sale of electric cars for the past few years.
Comparison between electric cars and gasoline cars
An electric car is powered by an electric motor. But, a gasoline car is powered by a petrol/diesel engine.
Since there are only electrical components, they are much easier to repair than other cars. They have only half the initial cost of a gasoline car. The power of electric cars is lesser than gasoline cars. But it is impossible to tell the difference between them while driving. While gasoline cars have a heavy noise, electric cars are smooth and silent while driving.
Hybrid cars have gained a lot of popularity nowadays. Among them, electric cars are the topmost in news. There has also been a trend of converting ordinary cars into electric cars. All you have to do is replace the engine with an electric motor and fit in an array of rechargeable batteries. You will also find that gasoline cars are very bulky in the interior with pipes, fuel lines and so on. But electric cars do not have any complexity. There are just a few wiring connections between each device.
How to make an electric car?
Modifying a gasoline car into an electric car
It is very simple to convert an ordinary car into an electric car. You must first know some basics about a gasoline car like the exact position of the engine, gas tank, muffler and so on. Here is a simple description of making an electric car.
For making an electric car the following components must be purchased.
- AC electric motors
- Electric controller
- Battery tray
- 12V Lead acid batteries
- Battery Charger
- Many motors for driving smaller parts
Given below is a well explained diagram of a car that shows both the physical components of an electrical as well as gasoline car. The comparison between them is also given.
Since the components for both the cars are different, they must be replaced. For this, all the major components like petrol/diesel engine, muffler, catalytic converter, petrol/diesel tank and also the exhaust pipe must be removed. The clutching mechanism must also be removed. There should not be any change in the manual transmission, except for its shifter. For further simplicity the shifter can be replaced with a switch, so that the forward and backward motion of the car can be controlled automatically. Connect the motor to the transmission. For controlled working of the AC motor, it must be connected to the controller. A number of lead acid batteries must be connected to the battery tray, which is correctly installed to the base of the car. For good driving response the battery must be able to produce at least 300V DC. For this, I would prefer two slots of the battery tray fitted with 25 batteries. For an ordinary car, the engine vacuum was used to give power to the bakes. In its absence a vacuum pump must be installed. Since the only driving source is from motors, the other mechanisms like power steering, water pump and also air conditioner should be connected to separate motors. Earlier they had driven power from the gasoline engine itself. As a part of maintenance, it is always better to include a recharger, so that the batteries can be automatically charged. For this, a 240V outlet is preffered.
Electric Car Statistics
Different parameters like mileage, speed, and life define the ability of a car. Here is an average reading of an electric car.
- The car has a maximum speed of 80km.
- The batteries have a life of almost three and a half to four years.
- All the batteries included weighs almost 500 kilograms.
- After a long drive, almost 12KW/h of electricity is needed to charge the car.
When comparing these parameters to an ordinary petrol/diesel car, you will get a huge difference in the pricing. There is almost 30% difference in the expense for each kilometre. But, the initial cost for an electric car will be very high. The batteries itself will cost up to $2000. They will last for a minimum of 25,000 miles.
Working of an Electric Car
An electric car simply consists of three main components – Battery, controller and electric motor.
The base of any car is the battery. As told earlier, the battery used for this car is very expensive. By using lead acid batteries, the weight of the car increases a lot (>>1000 pounds). As the number of batteries range from 50 to more, they occupy a lot of space as well. They generate lesser driving powers comparing to gasoline cars. After a long drive, they need at least ten hours to get recharged completely. Apart from the battery used for the car mechanism, there is also an additional 12 V battery on board. This is needed to provide power for other components like wipers, radio, and air conditioner and so on. But the extra expense comes when you have to recharge the battery. You will need a 300V Dc to 12V DC converter.
As told earlier we need 300V DC to drive the AC motor. This rating is converted to 240V AC and is sent to the motor with the help of the converter. This can only be done using a set of transistors, which will convert the DC signal into sine waves rapidly. Thus when the accelerator is fully pressed, the controller produces almost 96 V to the motor. If the accelerator is released, the controller delivers 0V. Thus the controller stands as a buyer of power from the battery and giver of power to the motor. As the accelerator is pressed in different modes, the controller is supposed to give an output power accordingly. So, variable potentiometers are connected between the accelerator and the controller, so that variable, but proportional power can be delivered to the motor. But, if the potentiometer goes wrong the result can be fatal. So, as a safety measure, there are two potentiometers connected to the accelerator. If both show equal value, then the controller proceeds. If they are different, the controller stops working. The greatest disadvantage of this is that the whole car stops working if a single potentiometer goes wrong. In most of the cars, the controller is just a normal switch with an ON position while accelerating and an OFF position while decelerating. But, this is difficult for the driver as he will not get a flow. Thus the controller acts as a pulsator. It notices the value of potentiometer and rapidly switches the proportional power to the motor.
The motors used in electric cars can be AC or DC. Mostly DC motors are preferred than AC motors because they are simple to configure and are not at all expensive. For AC motors 3-phase motors have to be used, running at 240V AC. DC motors, on the other hand requires only (96-192)Volts. DC motors can also be overdriven for a short period of time.