What is the difference between permanent magnet frequency conversion and ordinary frequency conversion

What is the difference between permanent magnet frequency conversion and ordinary frequency conversion

In the current air compressor market, energy saving has become the mainstream word in the industry. Energy-saving air compressors are emerging one after another, and the air compressor frequency conversion control technology is becoming more and more mature. In the frequency conversion control screw air compressor, it can be divided into two types: ordinary frequency conversion and permanent magnet frequency conversion. It is also controlled by inverter, so what is the difference between the two? Which energy saving effect is higher and lower?

　　 First of all, the permanent magnet variable frequency air compressor uses a high-efficiency rare earth permanent magnet motor, while the ordinary variable frequency is an ordinary three-phase asynchronous motor. There is a permanent magnet ring in the rare earth permanent magnet motor. The magnet ring releases the magnetic field when it is energized to generate Lorentz force. The working efficiency is high. Compared with the three-phase asynchronous motor of the same power, it is 5%-7% higher than the ordinary frequency conversion. Energy saving and power saving.

　　The permanent magnet motor will automatically adjust the frequency to change the motor power according to the change of the air volume at the user end, which matches the motor output power well, and its working efficiency remains at a high level no matter it is under light load or overload.

The permanent magnet motor and the compressor host adopts a built-in integrated shaft direct connection structure, no motor bearing, 100% transmission efficiency, and mechanical loss is smaller than ordinary variable frequency air compressor coupling transmission, eliminating failure points and reducing maintenance Cost and longer service life.

　　Second, the ordinary variable frequency screw air compressor adjusts the motor speed through an external inverter, thereby adjusting the exhaust volume, so that the gas production volume and the gas consumption volume are adapted to achieve the effect of energy saving. However, the motors used in ordinary screw air compressors are rated speed, rated power and rated power, and the external inverter forces the air compressor motor to deviate from the rated speed. Once the ordinary motor deviates from the rated speed, the efficiency will drop significantly, and the greater the deviation, the greater the efficiency drop.

Third, the adjustment range of an ordinary variable frequency air compressor is 50-100%, which means that when it deviates from the working condition by more than 50%, the ordinary frequency converter will not be able to adjust the motor speed, while the adjustment range of Aigao permanent magnet variable frequency air compressor It is 25%-100%, which means that the Ai Gao permanent magnet variable frequency air compressor can still work normally when it deviates from the working condition by 75%.

　　 To sum up, although both permanent magnet frequency conversion and ordinary frequency conversion use frequency conversion control to achieve the effect of energy saving, due to the role of permanent magnet motor, its energy saving effect is better and more stable.