A permanent magnet electric motor is a kind of brushless electric electric motor that uses long term magnets rather than winding in the field.
This kind of motor can be used in the Chevy Bolt, the Chevy Volt, and the Tesla Model 3. Other Tesla versions use traditional induction motors motors. Front motors in all-wheel drive Model 3 Teslas are also induction motors.
Permanent magnet motors are better than induction electric motor or motors with field windings for several high-efficiency applications such as electric vehicles. Tesla’s Chief Engine Designer was quoted talking about these advantages, saying: “It’s well known that permanent magnet devices 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 improve your efficiency. Both seem sensible for variable-acceleration drive single-gear tranny as the drive products of the cars. So, you may already know, our Model 3 includes a long lasting magnet machine now. The reason being for the specification of the functionality and efficiency, the long term magnet machine better solved our cost minimization function, and it had been optimal for the range and performance target. Quantitatively, the difference is certainly 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 used in the future.
The magnetic field for a synchronous machine could be provided by using long lasting magnets manufactured from neodymium-boron-iron, Transmission Chain samarium-cobalt, or ferrite on the rotor. In a few motors, these magnets are mounted with adhesive on the surface of the rotor core such that the magnetic field is radially directed across the surroundings gap. In other designs, the magnets are inset in to the rotor core surface or inserted in slot machine games just underneath the surface. Another type of permanent-magnet electric motor provides circumferentially directed magnets placed in radial slots that provide magnetic flux to iron poles, which in turn setup a radial field in the air flow gap.
The primary application for permanent-magnet motors is in variable-speed drives where in fact the stator comes from a variable-frequency, variable-voltage, electronically controlled source. Such drives are capable of precise speed and position control. Due to the lack of power losses in the rotor, as compared with induction engine drives, they are also highly efficient.
Permanent-magnet motors can be made to operate at synchronous swiftness from a way to obtain constant voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding is placed in slots in the rotor surface to provide starting capability. This kind of a motor will not, however, have method of controlling the stator power aspect.