Permanent magnet motor

A permanent magnet engine is a type of brushless 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 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 motor or motors with field windings for several high-efficiency applications such as for example electrical vehicles. Tesla's Chief Engine Designer was quoted discussing these advantages, stating: “It's well known that permanent magnet devices have the benefit of pre-excitation from the magnets, and therefore you have some efficiency benefit for that. Induction machines have perfect flux regulation and for that reason you can enhance your efficiency. Both make sense for variable-velocity drive single-gear tranny as the drive devices of the cars. So, as you know, our Model 3 includes a permanent magnet machine now. The reason being for the specification of the performance 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 usually what drives the future of the device, and it's a trade-off between motor cost, range and battery cost that is identifying which technology will be used 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 a few motors, these magnets are installed with adhesive on the top of rotor core in a way that the magnetic field is definitely radially directed across the air flow gap. In other designs, the magnets are inset into the rotor core surface or inserted in slot machines just underneath the surface. Another kind of permanent-magnet engine has circumferentially directed magnets placed in radial slots that provide magnetic flux to iron poles, which setup a radial field in the Transmission Chain atmosphere 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 managed source. Such drives are capable of precise speed and placement control. Due to the lack of power losses in the rotor, as compared with induction electric motor drives, they are also highly efficient.

Permanent-magnet motors can be made to operate at synchronous rate from a way to obtain constant voltage and frequency. The magnets are embedded in the rotor iron, and a damper winding is definitely placed in slots in the rotor surface area to supply starting capability. This kind of a motor will not, however, have method of controlling the stator power aspect.