Compared with the power frequency motor, the permanent magnet synchronous motor is easy to control, the speed is determined by the frequency of the power supply, the operation is stable and reliable, and it does not change with the fluctuation of the load and voltage. In view of the characteristics of strict synchronization of the speed of the permanent magnet synchronous motor, it determines the advantage of good dynamic response performance of the motor, which is more suitable for frequency conversion control.
Permanent magnet motor is a kind of energy-saving motor, and it has been well promoted in many application fields, but not all working conditions and occasions are necessary, or it is suitable to use permanent magnet synchronous motor. This is a question worth exploring.
From a theoretical analysis, permanent magnet synchronous motors are more suitable for loads with frequent load changes, and the motors often operate under no-load or light-load conditions, such as lathes, punching machines, chemical fiber, textile, and wire drawing equipment, and the final energy-saving effect is more obvious. , The average power saving rate can reach more than 10%.
In many occasions, especially for the working condition of the cage motor, in order to make the equipment start smoothly, the motor will be selected according to the maximum load of the equipment in most cases, which will inevitably lead to a relatively low load rate and a low motor capacity during normal operation. In the case of severe excess, when the motor is running, the efficiency is related to the size of the load. Generally, when the motor is running with no load, the efficiency is close to zero. When the load increases, the efficiency also increases. When the load reaches 70% of the rated load, the efficiency is the highest; therefore, when the motor is running close to the rated load, the efficiency is the highest, and it is also the most energy-saving and economical. If the supporting asynchronous motor is replaced by a high starting torque permanent magnet synchronous motor, the result of configuring energy input according to needs will greatly save energy. The advantage of permanent magnet synchronous motor lies in its two lows and two highs, that is, low loss and temperature rise, high power factor and high efficiency. This is exactly what people pursue for motor performance, and it also determines the market application status of permanent magnet motors.
Therefore, when selecting a supporting motor, the customer should conduct a comprehensive analysis in combination with the actual equipment and working conditions, not just stay at the motor body, but fully consider the energy-saving effect of the system.
Post time: Feb-17-2023