Ancillary Service Market Equilibrium Analysis for Multi-Agent Load Aggregators in Distribution System

The fluctuation of distributed energy and uncontrollable load increase the ancillary services demand for distribution system. With the development of smart grid, more and more load aggregators(LA) can participate in auxiliary service market by aggregating the controllable loads and achieve local balance, resulting in the break of the market equilibrium dominated by the power producers in the past. Therefore, this paper proposes a bi-level game model for multi-agent load aggregators to participate in auxiliary service market. The upper-level problem of the model maximizes the profit of each load aggregator in multi-variety auxiliary service market, while the lower-level problem represents the market clearing process by distribution system operator(DSO). And the proposed bi-level model is transformed into a single-level model by KKT condition and strong duality theory. Considering the non-cooperative game relationship between different load aggregators, the Nash equilibrium of market is calculated by particle swarm optimization algorithm. The validity and feasibility of the model is verified under three typical scenarios.