Different Types of Permanent Magnet Motors

PREVIEW

• How can permanent magnet motors be categorized?
• Features about different types of permanent magnet motors
• How to utilize permanent magnet motors under certain situations?

How can permanent magnet motors be categorized?

According to the magnet and attachment style and the design of the rotor, rotor permanent magnet synchronous motor can be divided into two categories:

• Surface permanent Magnet Synchronous Motor (SPMSM)
• Interiorpermanent magnet synchronous motor (IPMSM)

Features about different types of permanent magnet motors

Surface permanent magnet synchronous motor:

• 1. Permanent magnets are usually tile-shaped and located on the surface of the rotor core.
• 2. The main inductance of the direct and alternating axes are equal, with high efficiency and power factor.
• 3. High starting torque, which can produce a large torque in a short time, is suitable for the need for fast start occasions.
• 4. Owing to the truth that the permanent magnet is located outside the rotor, the structure is relatively simple to install and maintain.

Interior permanent magnet synchronous motor:

• 1. The permanent magnet is located inside the rotor, and there is a pole shoe made of ferromagnetic material between the surface of the permanent magnet and the inner circle of the stator core, which can protect the permanent magnet.
• 2. The main inductance of the direct and alternating axes is not equal, and the control characteristics are relatively complex.
• 3. Interiorpermanent magnet synchronous motor has high efficiency and power factor, and the energy saving effect is apparent.
• Because the permanent magnet is located inside the rotor, the structure is relatively complex, and the installation and maintenance are quite difficult.

How to utilize permanent magnet motors under certain situations?

Surface permanent magnet synchronous motor is primarily adapted to the following situations:

• Low speed, high torque application

Because the surface permanent magnet synchronous motor has a high torque capacity, it is suitable for occasions requiring low speed and high torque, such as lifting equipment, transportation equipment in the petrochemical industry.

• Occasions with high energy saving requirements

Surface permanent magnet synchronous motor has high efficiency and power factor, which can effectively reduce energy consumption, and is suitable for occasions with high energy saving requirements, such as fans and pumps in the industrial production process.

• Frequent starting and braking occasions: surface permanent magnet synchronous motor has high starting performance, suitable for frequent starting and braking occasions, such as material handling equipment, lifts, etc.
• In the case of low ambient temperature

Because the surface permanent magnet synchronous motor uses permanent magnet materials, its magnetic properties are affected by temperature to great extent. In low temperature environment, surface PMSM has better performance than interior PMSM.

Interior permanent magnet synchronous motor is mainly suitable for the following conditions:

• Occasions with high starting performance requirements

Due to the high starting performance of the interior permanent magnet synchronous motor, it is suitable for occasions that need to start quickly, such as the oil industry pumping unit.

• Occasions requiring higher efficiency

Interior permanent magnet synchronous motor has higher efficiency, which can effectively reduce energy consumption, suitable for occasions with higher energy saving requirements, such as fans and pumps in the industrial production process.

• The occasion of high ambient temperature

In high temperature environment, the interior permanent magnet synchronous motor has better performance than the surface permanent magnet synchronous motor.

• Occasions with high operating stability requirements

The interior permanent magnet synchronous motor has eminent operating stability, which is suitable for occasions with high operating stability requirements, such as the spindle transportation or in the textile industry.