A permanent magnet electric motor is a kind of brushless electric motor that uses long term magnets rather than winding in the field.
This type of motor is utilized in the Chevy Bolt[1], the Chevy Volt, and the Tesla Model 3.[2] Other Tesla models use traditional induction motors motors.[3] Front motors in all-wheel drive Model 3 Teslas are also induction motors.
Permanent magnet motors are better than induction motor or motors with field windings for certain high-efficiency applications such as electrical vehicles. Tesla’s Chief Engine Designer was quoted discussing these advantages, stating: “It’s well known that permanent magnet devices have the advantage of pre-excitation from the magnets, and therefore you have some efficiency advantage for that. Induction machines have perfect flux regulation and for that reason you can improve your efficiency. Both make sense for variable-rate drive single-gear transmission as the drive systems of the cars. So, you may already know, our Model 3 includes a long term magnet machine now. This is because for the specification of the overall performance and efficiency, the permanent magnet machine better solved our cost minimization function, and it had been optimal 
for the range and performance target. Quantitatively, the difference is usually what drives the continuing future of the device, and it’s a trade-off between motor cost, range and battery cost that is identifying which technology will be utilized in the future.
The magnetic field for a synchronous machine could be provided by using long lasting magnets made of neodymium-boron-iron, samarium-cobalt, or ferrite on the rotor. In a few motors, these magnets are installed with adhesive on the top of rotor core in a way that the magnetic field is usually radially directed across the surroundings gap. In other styles, the magnets are inset into the rotor core surface area or inserted in slot machine games just below the surface. Another kind of permanent-magnet engine provides circumferentially directed magnets positioned in radial slots offering magnetic flux to iron poles, which set up a radial field in the air flow gap.
The primary application for permanent-magnet motors is in variable-speed drives where the stator is supplied from a Transmission Chain variable-frequency, variable-voltage, electronically controlled source. Such drives can handle precise speed and placement control. Due to the lack of power losses in the rotor, as compared with induction engine drives, they are also highly efficient.
Permanent-magnet motors could be made to operate at synchronous acceleration from a supply of continuous voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding can be placed in slot machine games in the rotor surface area to supply starting capability. This kind of a motor does not, however, have means of managing the stator power aspect.