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

This kind of motor is used 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.

Long term magnet motors are more efficient than induction motor or motors with field windings for certain high-efficiency applications such as for example electric vehicles. Tesla’s Chief Motor Designer was quoted talking about these advantages, stating: “It’s well known that permanent magnet devices have the advantage of pre-excitation from the magnets, and therefore you involve some efficiency benefit for that. Induction devices have ideal flux regulation and therefore you can Stainless Steel Chain optimize your efficiency. Both make sense for variable-speed drive single-gear tranny as the drive models of the cars. Therefore, as you know, our Model 3 includes a long lasting magnet machine now. The reason being for the specification of the functionality and efficiency, the long lasting magnet machine better solved our cost minimization function, and it had been optimal for the number and performance focus on. Quantitatively, the difference is what drives the continuing future of the device, and it’s a trade-off between motor price, 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 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 surface of the rotor core in a way that the magnetic field is usually radially directed across the air gap. In other styles, the magnets are inset into the rotor core surface or inserted in slot machines just below the surface. Another type of permanent-magnet motor provides circumferentially directed magnets placed 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 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, in comparison with induction engine drives, also, they are highly efficient.

Permanent-magnet motors could be designed to operate at synchronous speed from a supply of constant voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding is usually placed in slot machine games in the rotor surface to provide starting capability. Such a motor will not, however, have method of controlling the stator power element.