A permanent magnet electric motor is a kind of brushless electric electric motor that uses long lasting magnets rather than winding in the field.
This kind of motor is utilized in the Chevy Bolt, the Chevy Volt, and the Tesla Model 3. Various other Tesla models use traditional induction motors motors. Front motors in all-wheel drive Model 3 Teslas are also induction motors.
Long term magnet motors are better than induction electric motor or motors with field windings for several high-efficiency applications such as for example electric powered vehicles. Tesla’s Chief Motor 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 involve some efficiency advantage for that. Induction machines have perfect flux regulation and for that reason you can optimize your efficiency. Both seem sensible for variable-rate drive single-gear transmission as the drive devices 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 permanent magnet machine better solved our price minimization function, and it had been optimal for the number and performance target. Quantitatively, the difference is what drives the continuing future of the machine, and it’s a trade-off between motor cost, range and battery cost that is determining which technology will be used in the future.
The magnetic field for a synchronous machine could be provided by using permanent magnets manufactured from neodymium-boron-iron, samarium-cobalt, or ferrite on the rotor. In some motors, these magnets are mounted with adhesive on the top of rotor core in a way that the magnetic field is usually radially directed across the air gap. In other designs, the magnets are inset in to the rotor core surface area or inserted in slot machines just below the surface. Another form of permanent-magnet motor has circumferentially directed magnets placed in radial slots offering magnetic flux to iron poles, which set up a radial field in the atmosphere gap.
The primary application for permanent-magnet motors is in variable-speed drives where in fact the stator is supplied 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, in comparison with induction engine drives, they are also highly efficient.
Permanent-magnet motors can be made to operate at synchronous speed from a supply of constant voltage and frequency. The magnets are embedded in the rotor iron, and a Leaf Chain damper winding is usually placed in slots in the rotor surface to supply starting capability. This kind of a motor does not, however, have method of managing the stator power factor.