A permanent magnet engine is a type of brushless electric motor that uses long lasting magnets instead of winding in the field.

This type of motor is used 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 better than induction engine or motors with field windings for several high-efficiency applications such as electric vehicles. Tesla’s Chief Motor Designer was quoted discussing these advantages, stating: “It’s popular that permanent magnet devices have the advantage of pre-excitation from the magnets, and for that reason you involve some efficiency benefit for that. Induction machines have perfect flux regulation and therefore you can enhance your efficiency. Both seem sensible for variable-acceleration drive single-gear tranny as the drive systems of the cars. So, as you know, our Model 3 includes a permanent magnet machine now. It is because for the specification of the overall performance and efficiency, the long lasting magnet machine better solved our cost minimization function, and it had been optimal for the number and performance target. Quantitatively, the difference is usually what drives the continuing future of the machine, 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 may be provided by using long lasting 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 atmosphere gap. In other designs, the magnets are inset in to the rotor core surface or inserted in slots just below the surface. Another type of permanent-magnet engine has 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 in fact the Conveyor Chain stator comes from a variable-frequency, variable-voltage, electronically controlled source. Such drives are capable of precise speed and position control. Because of the absence of power losses in the rotor, in comparison with induction motor drives, they are also 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 slots in the rotor surface area to provide starting capability. This kind of a motor will not, however, have means of controlling the stator power element.