Automatic Water Supply Control System of Graded Constant Pressure by Variable Frequency Speed and Its Application to Pipeline Irrigation

In pipeline irrigation system using pressurizing electromechanical pumps, the pumps usually work in constant speed under fundamental frequency power supply (50Hz) and the operation characteristics of pumps could not adapt to the practical changes of pipe network. When the irrigation area is huge or the gradient of field is high, the requirement of irrigation uniformity in the whole field can not be satisfied. Automatic water supply control system of graded constant pressure by variable frequency speed combines the frequency conversion and automation technologies, and is an electromechanical integrated intelligent device with functions of variable frequency speed control and automatic closed-loop control. This system switches pressure graded automatically according to required irrigation sub areas to realize graded and constant-pressure irrigation which could not only greatly enhance irrigation uniformity, but also has functions of saving water and energy as well as protecting the water pumps and the pipe network.