A Decentralized Voltage Control Strategy of Soft Open Points in Active Distribution Networks

Abstract

With the integration of high shares of distributed generators (DGs), it is increasingly difficult to cope with the risk of voltage violations and puts forward a higher requirement for the operational flexibility in active distribution networks (ADNs). Soft open point (SOP) is a novel power electronic device which can realize accurate power flow control and continuous voltage regulation. Currently, the centralized control strategy is mainly used to operate SOPs. However, the heavy burden of communication and complex global optimization processing will hinder its fast response to the frequent voltage fluctuations. This paper proposes a decentralized voltage control strategy of SOPs in ADNs. Based on the results of network partition, the alternating direction method of multipliers (ADMM) algorithm is applied to realize the decentralized optimization of the transmission power of SOPs among connected areas. The near-global optimal solution can be obtained without the huge calculation burden. The potential benefits of SOPs are fully explored to reduce power losses and improve the voltage profile of ADNs. Finally, the effectiveness of the decentralized voltage control strategy of SOPs is validated on the PG&E 69-node distribution system.