An enhanced decentralized voltage regulation scheme for the reduction of tap changes in HV/MV transformers under high DG penetration

In this paper, a decentralized control scheme is proposed that achieves two objectives: To mitigate overvoltages and to reduce the frequency of tap changes in the high/medium-voltage transformer. The proposed control is based on the reactive power capability of the distributed generation units, while actions are individually taken by each unit based only on local measurements. The validity of this method is examined through time-domain and time-series simulations. The former highlights the quick response and the robustness of the proposed control, whereas in the latter the performance and effectiveness of the proposed method in the long term is presented, focusing on the reduction of the transformer tap changes.