Research on cogging torque of the permanent magnet canned motor in domestic heating system

Abstract

The permanent magnet canned motor (PMCM) is a new type of energy-saving motor used in domestic heating system. Starting from the operating environment of the equipment, this paper studies the operating state of the motor. Based on the analysis of the motor structure and the maximum operating conditions, the method of weakening the cogging torque of the motor is studied, and the auxiliary slot method is selected to weaken the cogging torque of the PMCM. The finite element model of the motor is established, the influence of the number and type of auxiliary slots on the cogging torque is analyzed. Through analysis and calculation, it is concluded that the cogging torque of the motor can be reduced when the number of auxiliary slots is two. At the same time, compared with various slot types, the semicircular slot type has the smallest cogging torque. The circle helps to improve the flow of magnetic field and will not form corners and cause magnetic field deposition. This paper has certain engineering application value for the optimal design of the PMCM.

Keywords

• Auxiliary slot
• Canned motor
• Cogging torque
• Domestic heating system
• Finite element method
• Permanent magnet