how a motor works ?? ??
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Answer:
If you’re an electrical engineer, you know how an electric motor works. If you aren’t, it can be extremely confusing, therefore, here’s the simplified explanation (or the “how an electric motor works for dummies” version) of how a four pole, three phase AC induction motor works in a car.
It starts with the battery in the car that is connected to the motor. Electrical energy is supplied to the stator via the car’s battery. The coils within the stator (made from the conducting wire) are arranged on opposite sides of the stator core and act as magnets in a way. Therefore, when the electrical energy from the car battery is supplied to the motor, the coils create rotating magnetic fields that pull the conducting rods on the outside of the rotor along behind it. The spinning rotor is what creates the mechanical energy need to turn the gears of the car, which, in turn, rotate the tires.
Now, in a typical car that isn’t electric, there is both an engine and an alternator. The battery powers the engine, which powers the gears and wheels. The rotation of the wheels is what then powers the alternator in the car and the alternator recharges the battery. This is why you are told to drive your car around for a period of time after being jumped - the battery needs to be recharged in order to function appropriately.
In an electric car, there is no alternator. So, how does the battery recharge then? While there is no separate alternator, the motor in an electric car acts as both the motor and an alternator. That’s one of the reasons why electric cars are so unique. As referenced above, the battery starts the motor, which supplies energy to the gears, which rotates the tires. This process happens when your foot is on the accelerator - the rotor gets pulled along by the rotating magnetic field, requiring more torque. But what happens when you let off of the accelerator?
When your foot comes off the accelerator, the rotating magnetic field stops and the rotor starts spinning faster (as opposed to being pulled along by the magnetic field). When the rotor spins faster than the rotating magnetic field in the stator, this action recharges the battery, acting as an alternator.
To further simplify this process - imagine pedaling a bike up a hill. To get to the top of the hill, you need to pedal harder and may even have to stand up and expend more energy to rotate the tires and reach the peak of the hill. This is similar to pressing down on the gas. The rotating magnetic field pulling the rotor behind it creates the resistance (or torque) needed to move the tires and car. Once at the peak of the hill, you can take it easy and recharge while the wheels move even faster to take you down the hill. In the car, this happens when you let your foot off the gas and the rotor moves faster and feeds electrical energy back into the power line to recharge the battery.