Implementation and validation of a design model for photovoltaic water pumping system (PVPS).

Sammanfattning: Desertification is one of the main problems plaguing the Chinese countryside. The main cause is the heavy overgrazing of pastures and in this context the irrigation can be a solution to the problem. As regard the existent irrigations systems, pumps are driven manually or by diesel engines. Actually the use of electric motors would be a better solution for the irrigation development, but the lack of the access to electric network for the isolated rural areas represents a great obstacle. Therefore the use of PV stand-alone systems to produce the electricity for the motor-pumps (PVPS- Photovoltaic Pumping Systems) represents a both economic and technical good solution. However the weak point for PVPS diffusion is lack of tools to design these systems and predict their performances. This thesis work wants to provide a sizing software and the technical guidelines to select the suitable components for a PVPS. The developed sizing method has been validated applying it to two real cases where PVPS were already existing. Then, the obtained results have been compared with the characteristics of the real PVPS. The reliability of the design procedure has been verified, observing the similarity between the calculated outputs and the respective real values. Finally simulations have been done using the designed PVPS. The scope of those simulations has been to add some technical recommendations useful for the PVPS designer. The influence of the total head variations on the pumping performance and also the effect of the motor-pump subsystem choice on the final power size of PV array have been investigated.