Using the International advanced speed conversion module, strengthen the speed characteristics of special motor, a particular PID parameters suitable for screw compressor. Control software parameters setting are simple, interface amity. VACPAC variable speed screw compressor can be on duty continuously for 24 hours and give highly efficient performance. VSD variable speed drive technology according to the volume demand automatically adjusts the rotate speed of the motor, reduce the system pressure can make the entire production to reduce energy consumption and energy cost.