Permanent magnet variable frequency screw air compressor
The rise of permanent magnet variable-frequency screw air compressor in the last two years, what is the difference between permanent magnet variable-frequency screw air compressor and ordinary variable-frequency screw air compressor? Why is the price difference so much. Both of them are equipped with frequency converters, which is mainly different from the motor. The ordinary variable frequency screw air compressor is equipped with a traditional asynchronous excitation motor, while the permanent magnet variable frequency screw air compressor is equipped with a rare earth permanent magnet motor. The following is the difference between ordinary motor and permanent magnet motor. High efficiency permanent magnet synchronous motor Compared with induction motor, permanent magnet synchronous motor does not need reactive excitation current, can significantly improve power factor (up to 1, even capacitive), reduce stator current and stator resistance loss, and has no rotor copper loss during stable operation, thus can reduce fan (small capacity motor can even remove fan) and corresponding wind friction loss, Compared with induction motors of the same specification, the efficiency can be increased by 2 to 8 percentage points. In addition, the permanent magnet synchronous motor can maintain high efficiency and power factor in the range of 25%~120% of the rated load, which makes the energy-saving effect more significant when operating under light load. Generally, this kind of motor is equipped with a starting winding on the rotor, which has the ability to start directly at a certain frequency and voltage. At present, it is mainly used in oil fields, textile and chemical fiber industries, ceramic and glass industries, fans, water pumps, air compressors, etc.
