Renewable energy sources have increasingly been integrated into the power systems via inverter-based systems, as a result of the global drive toward clean energy concepts as well as the substantial advances in renewable and power electronics technologies. Renewable energy sources offer plenty of benefits from the environmental and sustainability point of view. However, they do pose significant challenges to the power system stability.

This thesis aims to investigate the stability concerns of the power system due to the inverter-based generations, especially when the power system is weak. Accordingly, two primary operational aspects related to voltage and transient stability will be examined. These are (a) system contingency in the vicinity of the inverter, and (b) the ability of the inverter to recover from a fault. Simulation models necessary to capture typical power system characteristics will be developed, and the issues mentioned above will be investigated in detail. Further, control solutions to mitigate those issues will be provided.

The application of the proposed control strategies will be demonstrated on a large practical power system. Consequently, dynamic simplification of the large power system must be performed as a compulsory step. The proposed control strategies will then be implemented in the dynamically simplified system, followed by the performance analysis to validate the efficacy of the proposed solutions.