Capturing opportunity costs of peer-to-peer energy transactions in microgrids via virtual state-of-charge bids

Since the prosumers can absorb or generate power in the P2P energy market, we equivalently model the prosumers as virtual energy storages (VESs) and employ the latest state-of-charge (SOC)-dependent bids to depict the prosumers’ bidding strategies. We first model the P2P market participants’ trading behaviors considering their loads, batteries, and distributed energy resources (DERs). To derive the equivalent VESs, we develop an algorithm to estimate the prosumers’ virtual capacities. We analyze the market operator’s model to guarantee energy delivery in the distribution network. Then, we project the operator’s network constraints to the prosumers’ feasible regions for privacy preservation and iteration reduction. Based on the virtual capacities, we develop VSOCs to depict the prosumers’ different trading states during market operation. We finally convexify the market-clearing problem and modify the alternating direction method of multipliers (ADMM) to calculate the optimal trading results with VSOC-dependent bids. Two cases are employed to verify that the VSOC-dependent bids can accommodate the prosumers’ parameter changes and trading preferences. The opportunity costs are reduced by 41.2% when allowing prosumers to bid differently in various VSOCs.