A local flexibility market framework for exploiting DERs' flexibility capabilities by a technical virtual power plant

This paper presents a new intra-day intra-hourly local flexibility market (LFM) framework to exploit distributed energy resources' (DERs) flexibility capabilities. A technical virtual power plant (TVPP) operates the LFM in which the DER aggregators participate. The TVPP offers the provided flexibility capabilities to wholesale flexibility market (WFM) as well as compensating the intra-hourly variability in power distribution network. In the proposed framework, the TVPP clears the LFM by considering hierarchical transactions with the aggregator agents to find the market equilibrium in which the DERs' flexibility capabilities are optimally exploited while all participating agents make profit by trading flexibility capabilities in the LFM. A bilevel optimization model with multiple lower levels is considered to address different agents' preferences and transactions in the LFM. In the upper-level problem, the TVPP aims at maximizing its profit while each lower-level problem represents an aggregator agent's optimization problem. The proposed model is reformulated into a single-level mixed integer linear programming problem and is implemented on the distribution network connected to Bus 5 of the Roy Billinton test system (RBTS) as well as a 119-bus test system. The results demonstrate the effectiveness of the model to utilize DERs' flexibility and provide revenue opportunities for different agents.