Water-level Control System for Solar Water Heating Engineering based on PLC

Focus on the problem that the dedicated controller of Solar Water Heating Engineering system cannot meet the needs of large-scale projects in man-machine interaction, intelligent control, remote monitoring, reliability and scalability, etc. This paper presents a water-level measurement and control scheme suitable for large-scale Solar Water Heating Engineering project based on PLC, industrial touch screen and Variable-frequency Drive. Firstly, the control circuit and sensor circuit are designed, and the closed-loop drive control system is formed by a water-level sensor, PID controller with PLC and water pump controlled by Variable-frequency Drive. Secondly, the control strategy is optimized and friendly man-machine interface is maintained. Experiments and engineering applications show that the system runs stably and have obvious energy-saving effect. It can well solve the above problems and has a high automation level and good performance targets. Therefore it is worth applying widely.