Most famous electric car manufacturer Tesla and other manufacturers used 3-phase induction motor due to the following reasons:
- Induction motors are more robust and reliable and do not require frequent maintenance due to the aging of different parts.
- Induction motors are self-starting and do not require any initial push from DC motor. Unlike in a gasoline engine, where a separate DC motor is used for providing an initial rotation.
- Although the induction motor has the issue of poor starting torque due to the low resistance of rotor winding. However, with the use of variable voltage variable frequency (VVVF) drive, the induction motor works efficiently by providing very high torque at low speed while consuming low current.
- The induction motor also provides the recharging of the battery. When electrical brakes are applied, the motor returns the regenerated power back to the battery. In this way, the motor works both as a motor normally and as a generator during the electrical braking operation.
- The induction motor has very accurate speed regulation, and its speed can be very easily varied by just changing the frequency through the controller.
- Induction motors are comparatively smaller in size as compared to the permanent magnet DC motors. As larger magnet will be required for a higher rating of a motor in terms of speed. In addition, cost-wise they are less expensive than other motors like the synchronous motor of equivalent rating.
Therefore, an induction motor is been chosen by many top manufacturers like Tesla, because according to above discussion, it is robust and most reliable with low maintenance issues. In addition size, cost, speed regulation and speed control also give them an advantage of our other motors. These are the few important reasons which influence the choice of induction motor for use in electric cars.