Inter-temporal Nodal Market Power Assessment in the Electricity Market Considering Generation Flexibility

Market power exercise of generating units has been a problematic issue affecting the fair and transparent trading of electricity markets. Therefore, it is of great significance to assess the market power of generating units in the electricity market. However, the previous assessment studies mainly focused on the static market power analysis, without considering the influences of inter-temporal generation flexibility, such as ramp rates. This paper proposes an optimization model for the ex-ante analysis of nodal market power of generating units in the multi-time ramp-constrained electricity markets. Moreover, two new indices are proposed to quantitatively evaluate the nodal market power considering generation flexibility. Finally, the proposed assessment method is validated on a modified IEEE 39-node system. The numerical results demonstrate that nodal market power can be greatly influenced by generation flexibility, particularly during the rapid fluctuations of load. The proposed indices are capable to reveal the inter-temporal nodal market power, and provide some valuable guidance for the identification and mitigation of market power in the electricity market.