Combined Generation and Transmission Expansion Planning Model for Improved Modern Power System Resilience

In recent times, the power grid composition is changing as more renewable energy generators and energy storage systems are being integrated. This in turn influences the dynamics of the new grid as frequency instability sets in due to declining system inertia. It is therefore important to properly select renewable energy generators and energy storage units to mitigate frequency instabilities, particularly during times of system contingencies. This study therefore, proposes a new deterministic generation and transmission expansion planning model that enhances the frequency stability of the modern grid. Thus, a mixed integer quadratic constrained programming model is developed to minimize emissions, and cost, while maximizing the overall system inertia. The proposed multi-objective model was validated using three case scenarios and tested on a modified IEEE 9-bus test system. The results obtained from the model simulation reveal that the proposed model (case 3) achieves better frequency stability, higher system inertia, and minimized emissions compared to the models in case 1(only economic objective is considered) and case 2(only economic and environmental objectives are considered), however, at a marginally higher cost which justifies the aim of the study.