A Protection Methodology for Supporting Distributed Generations with Respect to Transient Instability

The reliable and stable operation of electrical power systems is crucial for maintaining power delivery to end-users. Transient stability analysis is a fundamental aspect of power system protection. In addition, the increased penetration of distributed generations (DGs) into the power system creates new challenges for protection devices. Thus, understanding the impact of DGs on power system protection is critical. This study investigates the transient stability of a power distribution grid with DGs to determine the optimal protection settings for overcurrent relays (OCRs). Specifically, the study aims to propose a novel technique for calculating the modified value of the overcurrent relay time dial setting (TDS) to ensure the coordination of OCRs and prevent the instability of DG sources. The transient stability of DGs is evaluated under various fault locations and DG penetration rates. The constraints imposed by DGs are then considered in the protection coordination of OCRs. The proposed protection strategy maintains coordination between the overcurrent relays and prevents the instability of DG sources. To validate the effectiveness of the proposed protection strategy, numerical simulations are conducted using ETAP Software on an IEEE 33-bus distribution system. The simulation results show that the proposed method can achieve reliable protection coordination of OCRs and maintain the stability of DG sources. Finally, to enhance the proposed method’s practicality and efficiency, future research directions are identified, including the integration of artificial intelligence (AI) techniques into the proposed protection strategy. These efforts would consider the practical constraints and enable the proposed method’s scalability and applicability to larger and more complex power systems.