Enhanced Converter Control of a Stand-Alone Multilevel Photovoltaic System Featuring a Protection and Supervision System

Abstract

The focus of this paper is to optimize the control of a stand-alone discretized photovoltaic system and to reduce the power losses. High power installations require discretized photovoltaic systems. This architecture allows to avoid penalizing the entire system during a malfunction. However, its problems lie in the control of the converters of the adaptation stages and the monitoring of the global system in case of failure. The paper presents, on the one hand, an optimized control algorithm based on the Hill-Climbing method that takes into account the characteristics of the photovoltaic panels and the batteries used to improve the performance and reliability of the photovoltaic system, and, on the other hand, an automated energy management system and a remote supervision interface of the installation to ensure interaction with the site. The integration of the main blocks in our photovoltaic chain has guaranteed continuity of energy production, protection of equipment and reduction of intervention time in case of anomaly in the system. All the results obtained showed that the efficiency of the control of the adaptation stages is around 96%. The average relative error between the simulation and the experiment is 2.47%. After a daily measurement, the efficiency of the MPPT control (98.7%), the efficiency of the adaptation stages (88%) and the efficiency of the overall system (85%) are satisfactory and close to the optimal values of the overall system.