Factors causing torque pulsation of permanent magnet motors

Permanent magnet motors are widely promoted and used because they have many advantages that other motors do not have. But no matter what kind of machine, if it is used for a long time, some faults will definitely occur. We have also introduced the fault detection method of permanent magnet motors before. We can use hearing, smell and touch to analyze the fault and then give solutions.

Today we are mainly talking about the factors that cause torque pulsation of permanent magnet motors. I hope that after reading this, you can try to solve this type of problem yourself!

1. Torque ripple caused by current commutation

For this type of fault, we can use the overlapping commutation method to suppress the torque ripple caused by phase current commutation. In addition, we can also weaken the torque ripple caused by commutation by selecting the appropriate permanent magnet motor speed. Impact.

2. Torque pulsation caused by armature reaction of permanent magnet motor

For faults caused by this factor, we can reduce the impact of this reason by appropriately increasing the air gap. When designing the motor, try to choose a tile-shaped or annular permanent magnet radial excitation structure and a magnetic circuit. When designing, try to make the permanent magnet motor reach saturation when no-load. These methods can reduce this effect.

3. Torque pulsation caused by cogging effect

For faults caused by this reason, the common method is to reasonably select the pole slots of the permanent magnet motor, such as using inclined slots, or using inclined poles for the rotor. In addition, the air gap can be appropriately increased, and the use of fractional slots can also help reduce the number of teeth. Slot torque ripple, or making permanent magnet motors is also a new direction.

4. Motor torque pulsation caused by control algorithm error

We can improve the accuracy of current control by improving the current control algorithm to reduce current ripple, thereby reducing torque ripple. However, if you want to achieve a more cost-effective current control method for permanent magnet motors, you still need to conduct more in-depth exploration and research in practice.

5. Torque pulsation caused by mechanical processing factors

In actual production and processing, inconsistencies in the materials used to manufacture motors, rotor eccentricity, winding asymmetry, etc. will all cause torque pulsation. At this time, you can choose high-quality materials and improve the processing technology level to effectively weaken the permanent magnets. Influence caused by motor processing factors.