Network-aware Participation of Aggregators in NEM Energy and FCAS Markets

The integration of distributed energy resources (DER) has created a demand-side flexibility which can be traded in the electricity market by aggregators. However, generating bids that accurately represent the flexibility of consumers while maintaining the network limits is a challenging task--especially since the aggregators typically do not have access to the network data nor the bids of other aggregators. To overcome these challenges, we propose a price-generating bidding strategy enabling aggregators that share the same distribution network to participate in the energy and FCAS (frequency control ancillary service) markets. Complying with the Australian National Electricity Market (NEM), we develop energy-FCAS trapeziums that represent aggregators' energy and FCAS bid interdependency across their fleet of flexible consumers. We also obtain the prices at which the aggregators should submit their energy and FCAS bids. Moreover, to ensure network feasibility for any market clearing output, we obtain the network feasible region using three sets of optimal power flows (OPFs). Aggregators' trapeziums are then restricted to be within the network feasible region, making them ready to submit to the NEM. We illustrate the effectiveness of our proposed approach using 207 consumers being served by three aggregators in a 69-bus distribution network. The results show that our approach could increase aggregators' benefits by 18%, on average, compared to a price-taking approach.