The permanent magnet variable frequency (PM VSD) air compressor has been widely used in the industry, and it can not help but remind people of the fixed speed air compressor. Throughout the market, fixed speed air compressors have gradually withdrawn from people’s attention, replaced by PM VSD air compressors, so what is the difference between the two, and why are PM VSD air compressors welcomed by the market?
1. Stable air pressure:
1. Since the variable frequency screw air compressor utilizes the stepless speed regulation feature of the Inverter, it can start smoothly through the controller or the PID regulator inside the inverter; it can quickly adjust for occasions where the air consumption fluctuates greatly.
2. Compared with the upper and lower limit switch control of fixed speed operation, the air pressure stability is exponentially improved.

2. Start without impact:
1. Since the inverter itself contains the function of a soft starter, the maximum starting current is within 1.2 times of the rated current. Compared with the power frequency starting that is generally more than 6 times the rated current, the starting impact is small.
2. This kind of impact is not only on the power grid, but also on the entire mechanical system is greatly reduced.

3. Variable flow control:
1. The fixed speed air compressor can only work in one displacement, and the variable frequency air compressor can work in a relatively wide range of displacement. The frequency converter adjusts the motor speed in real time according to the actual gas consumption to control the exhaust gas volume.
2. When the gas consumption is low, the air compressor can automatically sleep, which greatly reduces the loss of energy.
3. The optimized control strategy can further improve the energy saving effect.

4. The voltage adaptability of the AC power supply is better:
1. Due to the over-modulation technology adopted by the inverter, it can still output enough torque to drive the motor to work when the AC power supply voltage is slightly lower; when the voltage is slightly higher, it will not cause the output voltage to the motor to be too high;
2. For the occasion of self-generating, the variable frequency drive can better show its advantages;
3. According to the characteristics of the VF of the motor (the variable frequency air compressor works below the rated voltage in the energy-saving state), the effect is obvious for the site with low grid voltage.

5. Low noise:
1. Most of the working conditions of the frequency conversion system work below the rated speed, the mechanical noise and wear of the main engine are reduced, and the maintenance and service life are prolonged;
2. If the fan is also driven by variable frequency, it can significantly reduce the noise of the air compressor when it is working.
The difference between variable frequency and power frequency is obvious.

The energy saving and efficiency advantages of permanent magnet variable frequency (PM VSD) air compressors are the necessary means to win the market.