Reverse active-reactive optimal power flow in ADNs: Technical and economical aspects

Since 1880s unidirectional power flows in electrical distribution networks (DNs) have been known as the usual case. But after 1990s due to the installation of new entities such as distributed generation (DG) units and battery storage systems (BSSs) bidirectional power flows would be the future case. Recently, a combined problem formulation for active-reactive optimal power flow (A-R-OPF) has been developed to utilize the economical benefits of operating both low- and medium-voltage active DNs (ADNs). In this paper, some technical and economical aspects of allowing reverse A-R-OPF in ADNs are highlighted. This is achieved by considering a real medium voltage ADN with a high penetration of wind and battery stations. The results show that considering a price for reactive energy in ADNs will lead to a huge amount of reverse reactive energy. This new phenomenon needs to be considered in operating and planning future ADNs.