Grid Congestion Management using Grouping of Renewable Energies based on Sensitivity Analysis and Grid Congestion Amount of Transmission Lines

This study proposes an output curtailment method for determining the output curtailment of renewable energy sources (REs) to mitigate grid congestion in transmission systems with a significant influx of REs. To manage congestion, minimizing the total REs output curtailment while avoiding the concentrated output curtailment on a specific RE is crucial. As a means of identifying effective curtailment targets for congestion mitigation, sensitivity analysis is being used for quantifying the congestion mitigation effect with curtailment. Furthermore, equality in output curtailment can be ensured by grouping REs of similar sensitivity and uniformly curtailing each group. Minimizing the curtailment of REs under the grouping-based approach requires forming a group of REs that is sensitive to frequently congested lines, considering the tendency of congestion occurrence in the whole grid. Consequently, this study proposes a method for determining the output curtailment rate of REs using grouping based on weighted sensitivity, considering the sensitivity of each RE and grid congestion. The effectiveness of the proposed method was evaluated by numerical simulation of congestion management over one year on a grid in the northern area of the Tohoku region in Japan. The results indicated that the proposed method was superior in terms of total REs curtailment and equality compared to the comparison method that does not consider the grid congestion amount.