Design and modelling of a large-scale solar water pumping system for irrigation in Saudi Arabia

Abstract

This thesis illustrates a comprehensive study of using a large scale solar water pumping system in Riyadh, Saudi Arabia. This system is applied on an average farm located in Riyadh which has an average water consumption of 245 m³/day. This study provides detailed system sizing and dynamic modeling. Sizing such a system has been carried out by using some useful tools such as Homer and PVsyst software. A 115 m deep well needs a 5.4 kW pump, 11.6 kW PV, 6.8 kW converter and 9, 200 Ahr- 12 V, batteries. The results of both softwares are compared to each other and showed almost the same system design. In addition, water cost has been estimated with the provided data, to be ₵4/m³. System dynamic modelling is done using MATLAB/Simulink which contains several models of sub systems such solar arrays, two stages DC-DC boost converter, energy storage, DC shunt motor, and centrifugal pump. The system dynamic modeling has been developed based on the sizing of the system. In order to improve the system efficiency, perturbation and observation (P&O) algorithm based maximum power point tracker (MPPT) was built in the system model for the first stage of the converter; as well as PID controller for the second stage. MATLAB/Simulink simulation shows that this system can deliver the required energy with quite satisfactory controller dynamic performance.