Design and Implementation of Energy-Saving Control System of Fan Based on PLC

For the purpose of improving the operation efficiency and automatic control ability of fan, exploring energy saving potential at large and realizing full use of energy, the energy-saving control system of fan based on PLC S7-200 is presented. According to the variation of performance curve and pipeline characteristic curve under different flow regulating methods, the principle of energy-saving through frequency conversion control is investigated. The output voltage and frequency of variable frequency power supply can be adjusted in time on the basis of air flow pressure change so that it can keep fans' power input fluctuating in the high efficiency area. The frequency conversion of the boiler draught fan in a power plant indicates its energy-saving effect. Through a concrete example, the evaluation of frequency conversion is analyzed. The result shows that the system possesses high power-factor, auto constant pressure, and good reliability, so it has strong practicability and engineering application value.