Optimizing Relay Protection in Distributed Generation Systems Through Intelligent Electronic Devices Powered by Current Transformers

The integration of Distributed Generation (DG) systems, particularly wind turbine generators (WTGs), into power grids presents significant challenges in protection and coordination due to their unique characteristics. Traditional protection methods, such as overcurrent protection, are often insufficient for generator systems with limited short-circuit current contributions. This paper explores the limitations of conventional relay protection for wind turbines, highlighting issues such as reverse power flow, false tripping, and inadequate selectivity. We propose a solution involving Intelligent Electronic Devices (IEDs) powered by current transformers (CTs) to improve protection functionality, adapt to changing network conditions, and enhance system reliability. The paper further discusses the advantages of IEDs, such as adaptive fault detection, real-time monitoring, and reduced downtime. We present an evaluation of various protection functions for wind turbines, including phase overcurrent, neutral overcurrent, and voltage-based protection, as well as the integration of IEDs with modern protection schemes. Finally, the feasibility of implementing CT-powered IEDs in a distribution network model is examined using the ETAP software suite, offering insights into their performance and impact on DG systems.