Detection and prevention of islanding problems in grid connected PV systems

Abstract

The increasing integration of Distributed Generation (DG) in power systems presents new challenges related to the protection and management of these units. A key issue for operators in such systems is the occurrence of unintentional islanding, also known as Loss of Mains (LOM), where a DG unit is disconnected from the main utility grid but continues to power an isolated section of the system. This thesis investigates and compares various islanding detection methods within grid-connected PV systems, focusing on their performance under different load conditions and assessing their responsiveness and reliability across diverse scenarios. The research reveals that while methods such as DC-Link Voltage and Rate of Change of Frequency (ROCOF) demonstrate high effectiveness and reliability, their performance is significantly influenced by load characteristics. Additionally, the study ensures that the proposed detection methods align with international standards such as IEEE 1547, confirming their compliance with established guidelines for distributed energy resources. This work contributes to optimizing the design and operational strategies of grid-connected PV systems, facilitating their seamless and secure integration into modern electrical grids.