Cooperated Bidding of Aggregators to Meet Eligibility Requirements of Ancillary Service Market

Aggregators, especially those with non-generating, energy-limited or uncertain resources, often have problems of not meeting the eligibility requirements of the electricity markets, which limits their opportunities to profit from the markets. To this end, this paper proposes a cooperated bidding model to help the unqualified aggregators to meet two main eligibility requirements, i.e., minimum power requirement and minimum duration time requirement. In specific, two cooperation models are built up in the pre-bidding process. An add-up power constraint is built to combine the small-power resources into a larger one, and a pack-up model is proposed to pack up the duration-unqualified resources into an equivalent qualified one. Then, the above models are embedded into the cooperated bidding optimization model. Two solving strategies, including a centralized optimization and a distributed optimization algorithm based on the alternating direction method of multipliers (ADMM), are developed. The latter one requires only the information of to-be-cooperated resources and interexchange power, which can better protect the private data of the cooperated aggregators. Case studies verify the feasibility and effectiveness of the proposed cooperation method.