Constraint-based interactive approach for equilibrium of interdependent gas and electricity markets

Abstract

Locational marginal gas price (LMGP) has been adopted in the modeling of interactive markets operated by electricity system operators (ESOs) and gas system operators (GSOs) because of its capability for preserving privacy in the coordination of electricity and gas systems. In this paper we look at the current price-demand iterative (PDI) algorithm approach to solving the LMGP-based interactive model and find that the PDI algorithm may have some difficulty achieving convergence. To address this convergence issue, a new interactive solution approach is proposed in this paper to find the equilibrium between an ESO and a GSO. First, a critical load interval (CLI) model of the gas system is proposed in order to identify new LMGPs as well as their preconditions, which can characterize the variation relationship of gas loads within several hours. Second, a solution technique is proposed to set the equality constraints from the CLI model and LMGPs as interactive information to search for the equilibrium point. The case study indicates that the proposed interactive approach has a better performance on convergence than the PDI algorithm with fewer convergence numbers when solving the interaction problem of GSOs and ESOs.