How does VFD Work on Air Compressor?
It is found that the speed of air compressor motor is proportional to the actual consumed power of the air compressor. Therefore, it is necessary to reduce the motor speed in order to reduce the actual consumption of the air compressor. The use of VFD in air compressor system can realize the real time control of motor speed (output power) without changing the air compressor motor torque through the accurate coordination of electrical control and frequency control in the air compressor system. To change the compressor speed to respond to the system pressure changes and to maintain stable system pressure can realize the output of high quality air pressure according to demand.
When the system consumption air volume is reduced, the compressed air provided by the air compressor is larger than the system consumption. The compressor will reduce its speed and decrease the output compressed air volume at the same time. On the contrary, to improve the motor speed to increase the air volume of compressed air can maintain a stable system pressure value. The function of VFD in its system is the same as the energy saving of fan electric motor water pump and the input voltage frequency is controlled according to the change of the load.
How does VFD work on the air compressor? The principles of energy saving and effect are as follows.
- After using VFD, the set of air compressor should meet the minimum pressure requested by the production equipment as the setting pressure. The VFD will adjust the speed of the compressor, even eliminate the unloading operation of the air compressor, and save the electric energy according to the trend of the fluctuating of pipe network pressure.
- Because the VFD in the system can stabilize the up and down pressure of pipe network and reduce or even eliminate the pressure fluctuations so that all air compressors in operation in the system can run in the lowest pressure that can meet the production requirement and reduce the power loss caused by the fluctuation of upward pressure.
- Because the air compressor can not exclude the possibility of long time operation under full load condition, the capacity of motor can only be determined according to the maximum demand, the capacity is generally designed larger. In actual operation, the proportion of light load running time is very high. If the frequency control is adopted, the working efficiency of the operation can be greatly improved. Therefore, it has great potential for energy saving in the air compressor system.
- Some regulating method(regulating valve opening and angle of the changing blade) can not reduce the operating power of the motor even in the case of small demand quantity. After adopting frequency control, it can reduce the speed of the motor and the operating power of the motor so as to realize energy conservation even in small demand quantity.
- The single motor drag system can not be adjusted continuously according to the weight of the load. After using frequency control, which can maintain the stability of parameters such as pressure, flow, temperature and so on, thus greatly improving the performance of the air compressor.