Bi-Level Low-Carbon Optimal Operation Model of Multi-Energy Aggregator in Energy and Flexibility Market

Under the background of low-carbon transition, the development of renewable energy is an inevitable trend, making an increasing demand for flexibility. Multi-energy Aggregators (MEA) with multi-energy coupling devices can coordinate various energy sources to reduce carbon emissions, and provide flexibility for the electricity system as well. This paper proposes an interdependent electricity and natural gas market framework considering carbon-related costs and the flexibility market deployment to facilitate MEA to participate in the energy and flexibility trading. This problem is constructed as a bi-level optimization model. In order to promote carbon emission reduction, the upper model considers carbon-related costs when constructing the market model, and proposes the energy-carbon integrated pricing method. Furthermore, the clearing models of electricity, natural gas and flexibility markets are established. The lower-level model focuses on the optimal operation model of MEA to minimize its operational cost. The proposed bi-level model is transformed into a single-level mixed-integer second-order-cone programming (MISOCP) model by Karush-Kuhn-Tucker (KKT) conditions and duality theory. The case study verifies the effectiveness of the proposed model and solution method.