Modeling and Planning Operation of Directly Coupled Solar Photovoltaic Pump Operated Drip Irrigation System with a Case Study

An integrated dynamic simulation model of a directly coupled solar photovoltaic pump-operated drip irrigation system is developed and presented in this study. The model is applied for system evaluation and preparing a plan of drip irrigation system operation to meet the irrigation schedule of the Okra crop considered in the case study. The fundamental mathematical expressions of the solar photovoltaic array, variable frequency drive, submersible pump, and drip irrigation system are used to create a generic simulation model in the Matlab/Simulink environment. The hourly solar irradiation, temperature, and groundwater level are input parameters to the model. The output such as solar photovoltaic power, pump discharge and pressure head, and emitter discharges are simulated on an hourly basis. The simulated values of these parameters for the same period are compared with the measured values and the model accuracy is evaluated statistically. The coefficient of determination (R2) greater than 0.98 for all the subsystems shows good agreement between the measured and the simulated values. Further, the higher Nash–Sutcliffe model efficiency (> 0.77) and lower negative coefficient of residual mass statistic (close to 0) indicates the model is performing perfectly with a slight tendency to overestimate. The developed simulation model is applied in a case study to operate different subunit manifolds of a drip irrigation system installed in an Okra crop field of 1.2 ha. The total utilizable solar photovoltaic energy is found between 14 and 20 kWh/day. The satisfactory emission uniformity (greater than 85