"AC Fan" simple adjustment way is to use baffle or valve to adjust the air volume or flow to meet the load requirements change, the energy loss is very serious. Therefore, by changing the motor speed to achieve or adjust the air volume flow, undoubtedly save energy, improve equipment efficiency is of great significance. High pressure air is the main industrial production of power equipment, application of high power electric motor is more prominent, and most of these devices there is great potential for energy savings.