A permanent magnet electric motor is a type 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] Various other Tesla models use traditional induction motors motors.[3] Front motors in all-wheel drive Model 3 Teslas are also induction motors.
Long term magnet motors are more efficient than induction motor or motors with field windings for several high-efficiency applications such as for example electric vehicles. Tesla’s Chief Engine Designer was quoted talking about these advantages, stating: “It’s well known that permanent magnet machines have the advantage of pre-excitation from the magnets, and therefore you have some efficiency benefit for that. Induction devices have ideal flux regulation and for that reason you can enhance your efficiency. Both seem sensible for variable-quickness drive single-gear transmitting as the drive units of the cars. So, as you know, our Model 3 includes a long lasting magnet machine now. This is because for the specification of the efficiency and efficiency, the permanent magnet machine better solved our price minimization function, and it was optimal for the number and performance focus on. Quantitatively, the difference is what drives the Conveyor Chain future of the machine, and it’s a trade-off between motor price, range and battery price that is identifying which technology will be utilized in the future.
The magnetic field for a synchronous machine could be provided by using long term magnets made of neodymium-boron-iron, samarium-cobalt, or ferrite on the rotor. In some motors, these magnets are mounted with adhesive on the top of rotor core such that the magnetic field is definitely radially directed over the atmosphere gap. In other styles, the magnets are inset into the rotor core surface area or inserted in slots just underneath 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 atmosphere gap.
The primary application for permanent-magnet motors is in variable-speed drives where the stator is supplied from a variable-frequency, variable-voltage, electronically managed source. Such drives are capable of precise speed and position control. Due to the absence of power losses in the rotor, in comparison 
with induction engine drives, they are also highly efficient.
Permanent-magnet motors could be made to operate at synchronous swiftness from a way to obtain continuous voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding is certainly placed in slots in the rotor surface area to provide starting capability. Such a motor does not, however, have means of managing the stator power aspect.