Reducing the impact of degradation causes on electrical power sources in the photovoltaic water pumping system

Abstract

The availability and accessibility of water are the main issues for irrigation in most desert areas, especially in Jerid Tunisia. One of the best alternative methods for irrigation is the use of Photovoltaic Water Pumping Systems (PVWPS). Despite the considerable improvements in the design and performance of PVWPS, the presence of the peak load current, unsuitable battery charging control as well as inefficient energy management remain the major impediments to its evolution. In this context, the main focus of this paper is to improve the PVWPS reliability by reducing the occurrence and impact of degradation causes on electrical power sources. Firstly, a description of PVWPS configuration and its operation for irrigation is provided. Then, the critical causes generating the degradation of the various electrical power sources such as the Photovoltaic (PV) generator and the battery pack are identified. In order to minimize the impact of the peak load current on the electrical power sources, the authors propose the integration of a Hybrid Energy Storage System (HESS). In addition, the minimization of gassing phenomenon, no-cohesion of the active mass and sulfating of the electrode of the battery pack is ensured by using optimized multi-steps charging current profile. This study is completed by the integration of an Energy Management System (EMS) able to monitor, control and optimize the use of the various electrical power sources. The simulation results highlight the effectiveness of the proposed HESS and the optimized multi-steps battery charging current profile to ensure maximum availability and reliability of the PVWPS.