Permanent magnet motor

A permanent magnet engine is a kind of brushless electric motor that uses permanent 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 lasting magnet motors are more efficient than induction electric motor or motors with field windings for several high-efficiency applications such as for example electric powered vehicles. Tesla’s Chief Electric motor Designer was quoted discussing these advantages, saying: “It’s well known that permanent magnet machines have the benefit of pre-excitation from the magnets, and for that reason you involve some efficiency advantage for that. Induction machines have perfect flux regulation and for that reason you can improve your efficiency. Both seem sensible for variable-speed drive single-gear tranny as the drive units 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 performance and efficiency, the permanent magnet machine better solved our cost minimization function, and it was optimal for the number and performance focus on. Quantitatively, the difference is certainly what drives the future of the device, and it’s a trade-off between motor price, range and battery price that is determining which technology will be used in the future.
The magnetic field for a synchronous machine could 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 mounted with adhesive on the surface of the rotor core in a way that the magnetic field is usually radially directed across the surroundings gap. In other designs, the magnets are inset into the rotor core surface or inserted in slots just underneath the surface. Another type of permanent-magnet motor offers circumferentially directed magnets positioned in radial slots that provide magnetic flux to iron poles, which set up a radial field in the surroundings 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 controlled source. Such drives can Drive Chain handle precise speed and position control. Because of the lack of power losses in the rotor, as compared with induction engine drives, also, they are highly efficient.

Permanent-magnet motors could be made to operate at synchronous quickness 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 to supply starting capability. Such a motor will not, however, have means of managing the stator power aspect.