The residual magnetic characteristics of motor magnets have a crucial impact on the torque output during the operation of the motor. A deep understanding of its influence mechanism is of great significance for the optimization of motor performance.
First, the residual magnetic characteristics directly determine the initial strength of the motor magnetic field. Motor magnets have a certain residual magnetism after magnetization, and this residual magnetism will establish a magnetic field in the air gap of the motor. When current is passed through the motor winding, the magnetic field generated by the current interacts with the residual magnetic field of the magnet. Higher residual magnetism can produce a stronger initial magnetic field, so that the motor can generate a larger electromagnetic torque during the startup phase, so that the motor can overcome the load resistance and start more quickly. For example, in some industrial motors that require high starting torque, the selection of magnet materials with good residual magnetic characteristics can effectively ensure the smooth start of the motor and reduce the startup time and energy consumption.
Secondly, the stability of residual magnetism affects the consistency of the motor torque output. During the long-term operation of the motor, if the residual magnetism of the motor magnets is unstable, the magnetic field strength will fluctuate. This will make the torque output of the motor no longer uniform, which may cause the motor speed to fluctuate, vibrate, or even lose step. Especially in some application scenarios with high requirements for torque accuracy, such as the motor drive system of CNC machine tools, slight changes in residual magnetism may affect the processing accuracy. Therefore, ensuring that motor magnets have stable residual magnetism characteristics is one of the key factors in maintaining stable torque output of the motor.
Furthermore, the residual magnetism characteristics are closely related to the load adaptability of the motor. When the motor faces different load changes, its torque output needs to be adjusted accordingly. Appropriate residual magnetism enables the motor to effectively increase the torque to meet the load requirements by relying on the synergy of magnetic field and current when the load increases. If the residual magnetism is too small, the motor may not be able to provide enough torque under heavy load, resulting in a decrease in motor speed or even stalling; while if the residual magnetism is too large, the motor may have excessive torque output under light load, causing energy waste and motor heating.
Finally, from the perspective of motor efficiency, residual magnetism characteristics also play an important role. Reasonable residual magnetism can optimize the electromagnetic conversion efficiency of the motor, so that while generating the required torque, unnecessary energy loss is reduced. By precisely designing the residual magnetic parameters of motor magnets, the motor can find the best balance between torque output and energy consumption under different working conditions, thereby improving the overall operating efficiency of the motor, reducing operating costs and extending the service life of the motor.
