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Kaishan PMVF compressor. Kaishan ingenuity has resulted in the global release of these revolutionary new rotary screw air compressors that bring together an integrated systematic optimization of an advanced permanent-magnet motor combined with a variable speed drive and Kaishan single and 2-Stage rotary screw technology to achieve outstanding energy efficiency. This unique, integrated technology offers unsurpassed efficiency in industrial air compressors from 15 to 400kW. The range of Kaishan PMV compressors can be ideally matched to the needs of virtually any industry application.

Permanent Magnet Variable Frequency Rotary Screw Air Compressors

Developed by Kaishan Engineers, these revolutionary new rotary screw air compressors bring together an integrated systematic optimization of the compressor unit, an advanced permanent-magnet motor, and Kaishan SKY technology to achieve outstanding energy efficiency. This unique integrated combination is a game changer in the compressed air industry offering unsurpassed efficiency in compressors all the way down to 15kW.

Rare earth material technology gives the permanent-magnet synchronized motors higher possible rotating speeds, wider operating parameters, and increased energy efficiency. Within their wide operating speed range, the Permanent Magnet Variable Frequency rotary screw air compressors are able to maintain extremely high motor efficiency compared with those using conventional drive motors.

The fully enclosed oil-cooled Permanent Magnet motor generates very little heat, resulting in a longer life. No cooling fan means significantly lower noise and less fan drag compared with conventional motors. The motor is heat resistant to 180⁰ C and cannot be magnetized. With no external electrical excitation, the motor maintains a power factor close to unity. The precision speed adjustment capability (1/30,000) greatly reduces discharge fluctuations of the new range of air compressors.


Motor angular position sensors are not required, simplifying the system and improving both stability and reliability. Torque can be compensated at any angle within 360⁰ to achieve perfect torque control and the utilization of bus voltage is greater than 93%, which is much greater than conventional inverters.


If basic Variable frequency screw air compressor deviates from its designated working specifications, its efficiency drops. Kaishan’s Permanent Magnet Variable Frequency technology can adjust the motor’s rotating speed according to demand variations at any time.

By regulating the volume of air output, the compressor can maintain maximum efficiency under all usage demands from 15% to 100%. Particularly in applications with widely fluctuating demand, Kaishan’s Permanent Magnet Variable Frequency type air compressors demonstrate a remarkable energy saving capacity as high as 50% over conventional types.


  • Complete control of air output to meet operating demand

  • Lower energy input for required air generation

  • Excessive part-load energy consumption is significantly reduced. Gradual increase in motor speed eliminates starting spikes and cost penalties

  • A steady system pressure is maintained, lowering system stress and overall air demand

  • Reduced artificial demand due to lower operating pressures.

  • Reduced maintenance time and cost

  • Significantly lower noise levels

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