Southern Cross Compressors has released details of its new generation of compressors, combining permanent-magnet variable-frequency technology with next-generation two-stage screw airends. Developed by parent company Kaishan Corporation, these revolutionary new compressors bring together an integrated systematic optimisation of the compressor unit, an advanced permanent-magnet motor and Kaishan two-stage technology to achieve outstanding energy efficiency.
According to Martin Curd, Southern Cross National Sales Manager, “This unique integrated combination is a game changer in the compressed air industry offering unsurpassed efficiency in compressors all the way down to 22kW. We can now offer a superior range of advanced energy saving compressors for virtually any industry application.”
Two-stage air compressors are up to 20% more efficient than a typical single-stage compressor. As the compression ratio is spread over two distinct airends, customers get the benefits of both higher efficiency and longer bearing life.
Dr Yan Tang is General Manager of Kaishan and one of the world’s foremost experts in air compressor development. He says: “With global energy costs constantly rising, we are continually developing higher efficiency compressors that meet and surpass international energy standards. The high efficiency of our newly developed two-stage screw units is the fundamental reason for our PMVF compressor’s class leading performance. Our unique package design and engineering offers obvious technological advantages including screw compressor unit efficiency, drive motor efficiency and overall unit control.”
Rare earth material technology gives the permanent-magnet synchronised motors higher possible rotating speeds, wider operating parameters and increased energy efficiency. Within their wide operating speed range the PMVF compressors are able to maintain extremely high motor efficiency compared with those using conventional drive motors.
With an operating variable speed turndown range of 7:1 (conventional VS compressors 4:1), Kaishan’s PMVF operates at peak efficiency even with an 80% reduction in air output. It also offers far greater integrated control precision through an advanced PID control algorithm that provides highly stable supply pressures.
The fully enclosed oil-cooled PM 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 magnetised. With no external electrical excitation the motor maintains a power factor close to 1.
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 utilisation of bus voltage is greater than 93%, which is much greater than conventional inverters.
Once a mains frequency screw air compressor deviates from its designated working specifications, its efficiency drops. Kaishan’s PMVF technology is able to adjust the motor’s rotating speed according to demand variables at any time. By regulating the volume of air output, the compressor is able to maintain maximum efficiency under all usage demands from 15 to 100%. Particularly in applications with widely fluctuating demand, Kaishan’s PMVF type air compressors demonstrate a remarkable energy saving capacity as high as 50% over conventional types.
Southern Cross is in the final stages of obtaining all necessary statutory approvals for the new range which is expected to be launched later this year.
Southern Cross Compressors (Australia)
1300 098 901