Closed-Loop Control of Flow Under the Influence of Varying Temperature in Air Blower System Using PLC and VFD

摘要

The main objective of this paper is to design and implement the closed-loop control of mass flow rate in the air blower system when air is under the influence of varying temperature. As mass flow rate of air changes with the temperature, it can be maintained to desired value only by varying the blower speed suitably. For this purpose, we have used mainly programmable logic controller (PLC) and variable frequency drive (VFD). Based on the difference between actual and desired value of flow rate, PLC increases or decreases the speed of air blower operated by three-phase induction motor through VFD to maintain the desired air flow rate under the influence of varying temperature. Obtained results clearly indicate that desired value of flow rate is achieved nicely even under the influence of variation in the temperature.