Effects of loss models on locational reserve policies in uncertain power systems

Renewable energy sources (RES) often provide intermittent power at distributed locations in transmission and distribution networks. Storage devices distributed across the network are recognized as an important tool for compensating such power fluctuations. Operational policies of storage devices considered in literature focus solely on network balance. Here, the consumed network capacity is also considered. A linear network model with uncertain power and storage elements is supplemented with three possible models of line losses. Policy computation is formulated in each case as a convex optimization problem. The different solutions are compared in terms of computational complexity and policy structure. A single solution shows preference for local energy storage and remains computationally efficient. Other solutions either do not respond to uncertainty or attempt to reduce uncertainty using unnecessary power transmissions. Hence, the results yield a useful loss model as well as characterize undesirable behaviors that should be avoided with future models.