What Is The Difference Between A Permanent Magnet Motor And A Magnetic Aid Motor?

There are many differences between permanent magnet motor and magnetic assistant motor, mainly reflected in the following aspects:

How it works:

Permanent magnet motor: mainly uses permanent magnets to generate magnetic fields. A permanent magnet is a highly magnetic material that is able to establish a stable magnetic field in a motor. When the current passes through the stator winding of the motor, a rotating magnetic field is generated in the stator, which interacts with the magnetic field of the permanent magnet, thereby rotating the rotor of the motor and achieving the conversion of electrical energy to mechanical energy.

Magnetic aid motor: Magnetic aid technology is usually to add auxiliary magnetic materials or devices in the rotor or stator of the motor to enhance the magnetic field of the motor. For example, permanent magnet assisted synchronous reluctance motor, adding permanent magnet to the magnetic barrier of the rotor core, forming a polymagnetic structure, using the different permeability of the oriented silicon steel sheet in different directions and the auxiliary excitation of the permanent magnet, to improve the convex range and power density of the motor.

Magnetic field characteristics:

Permanent magnet motor: The magnetic field strength generated by permanent magnet is relatively fixed, and the stability of the magnetic field is high during the operation of the motor, but because the magnetism of the permanent magnet is difficult to adjust, the speed regulation range of the motor may be limited to a certain extent.

Magnetic aid motor: The magnetic field can be adjusted and enhanced to a certain extent through magnetic aid devices or materials. For example, in some cases, the strength of the magnetic aid can be dynamically adjusted according to the load of the motor, so that the motor can maintain good performance under different working conditions.

Motor structure:

Permanent magnet motor: The structure is relatively simple, usually composed of stator, rotor, permanent magnet, winding and other components. Permanent magnet on the surface of the rotor or embedded in the iron core, in order to protect the permanent magnet, at both ends of the rotor will be added protection plate.

Magnetic aid motor: In addition to the basic motor structural components, it also contains additional magnetic aid components or structures. For example, the permanent magnet assisted synchronous reluctance motor has a multi-layer magnetic barrier punched on the rotor core, and the magnetic barrier part is filled by oriented silicon steel sheet and permanent magnet.

Performance characteristics:

Permanent magnet motor: has the advantages of high efficiency, high power density, low noise, etc., can output large power under small volume and weight.

Magnetic assistant motor: to a certain extent, it combines the advantages of traditional motors and permanent magnet motors, with high power factor and torque density, which can improve the efficiency and performance of the motor, and has better adaptability under some special working conditions.

Cost:

Permanent magnet motor: If the use of high-performance permanent magnet materials, such as rare earth permanent magnets, the cost of the motor will be relatively high. However, with the continuous development of permanent magnet material technology and the expansion of production scale, the cost is also gradually reducing.

Magnetic aid motor: Due to the need for additional magnetic aid devices or materials, its manufacturing cost may be slightly higher than that of ordinary motors, but the cost may be reduced compared to motors that use high-performance permanent magnet materials entirely. Especially in some cost-sensitive application scenarios, magnetic-assisted motors have certain advantages.