A permanent magnet motor is a type of brushless electric motor that uses permanent magnets rather than winding in the field.

This type of motor can be used in the Chevy Bolt[1], the Chevy Volt, and the Tesla Model 3.[2] Other Tesla versions use traditional induction motors motors.[3] Front motors in all-wheel drive Model 3 Conveyor Chain Teslas are also induction motors.

Long lasting magnet motors are better than induction motor or motors with field windings for certain high-efficiency applications such as electric vehicles. Tesla’s Chief Engine Designer was quoted talking about these advantages, stating: “It’s well known that permanent magnet machines have the benefit of pre-excitation from the magnets, and for that reason you have some efficiency benefit for that. Induction machines have ideal flux regulation and therefore you can enhance your efficiency. Both make sense for variable-quickness drive single-gear tranny as the drive products of the cars. Therefore, as you know, our Model 3 includes a permanent magnet machine now. This is because for the specification of the performance and efficiency, the long term magnet machine better solved our cost minimization function, and it was optimal for the range and performance focus on. Quantitatively, the difference is definitely what drives the continuing 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 may be provided by using long term magnets manufactured from neodymium-boron-iron, samarium-cobalt, or ferrite on the rotor. In a few motors, these magnets are installed with adhesive on the surface of the rotor core such that the magnetic field can be radially directed over the air flow gap. In other styles, the magnets are inset in to the rotor core surface or inserted in slot machine games just below the surface. Another type of permanent-magnet engine offers circumferentially directed magnets positioned in radial slots that provide magnetic flux to iron poles, which in turn setup a radial field in the surroundings gap.

The main application for permanent-magnet motors is in variable-speed drives where the stator comes from a variable-frequency, variable-voltage, electronically managed source. Such drives can handle precise speed and position control. Due to the absence of power losses in the rotor, as compared with induction electric motor drives, they are also highly efficient.

Permanent-magnet motors could be made to operate at synchronous rate from a way to obtain continuous voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding can be placed in slot machines in the rotor surface area to provide starting capability. Such a motor will not, however, have method of controlling the stator power element.