A permanent magnet electric motor is a type 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[1], the Chevy Volt, and the Tesla Model 3.[2] Additional Tesla versions use traditional induction motors motors.[3] Front motors in all-wheel drive Model 3 Teslas are also induction motors.
Permanent magnet motors are more efficient than induction 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, stating: “It’s well known that permanent magnet devices have the benefit of pre-excitation from the magnets, and therefore you involve some efficiency benefit for that. Induction machines have ideal flux regulation and therefore you can enhance your efficiency. Both seem sensible for variable-quickness drive single-gear tranny as the drive products of the cars. So, as you know, our Model 3 includes a permanent magnet machine now. This is because for the specification of the efficiency and efficiency, the permanent magnet machine better solved our price minimization function, and it was optimal for the range and performance focus on. 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 price that is determining which technology will be utilized in the future.
The magnetic field for a synchronous machine may be provided by using long lasting 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 such that the magnetic field is certainly radially directed across the atmosphere gap. In other designs, the magnets are inset in to the rotor core surface or inserted in slot machines just below the surface. Another form of permanent-magnet motor has circumferentially directed magnets positioned in radial slots offering magnetic flux to iron poles, which create a radial field in the surroundings gap.
The main 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, in comparison with induction electric motor drives, they are also highly efficient.
Permanent-magnet motors could be designed to operate at synchronous speed from a way to obtain continuous voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding is placed in slot machine games in the rotor surface area to provide starting Stainless Steel Chain capability. This kind of a motor will not, however, have method of controlling the stator power element.