Optimised curtailment of distributed generators for the provision of congestion management services considering discrete controllability

Abstract

Grid operation becomes a more challenging task due to the increasing amount of distributed generators in the system. Consequently, critical situations with violations of operational limits occur more frequently. Hence, grid operators have to take corrective countermeasures to ensure the security of supply. This study presents a discrete optimisation approach to determine the optimal amount of distributed generator curtailment regarding multiple objectives. The proposed method is based on non-linear AC load flow analysis of the network. The method is implemented into a modified version of the IEEE 14-bus test system and the necessary amount of generation curtailment to retain predefined operational limits is identified. Simulations are carried out for different contingency scenarios and several possible increments of curtailment levels are compared. Results reveal the potential to reduce the total amount of power adjustments distinctly by using curtailment levels with smaller step sizes compared to todays' applied standards in German grid operation. Furthermore, the developed methodology enables distributed generators to be used for managing congestions of transformers connecting different voltage levels.