Optimal scheduling of bidirectional coupled electricity-natural gas systems based on multi-port gas network equivalent model

Abstract

Electricity and natural gas are combined in many technological fields such as gas-fired generation and power-to-gas. However, the information set is not fully shared between the operators of electricity system and natural gas system. When the natural gas network model is unknown and the measurement information is insufficient, assessing the state of the gas network is crucial for the reliable and efficient operation of interconnected electricity and natural gas system (IEGS). In order to solve this problem, this paper investigates an optimal scheduling method based on a multi-port gas network equivalent model, which is extracted from the real-time monitoring information. Firstly, Taylor's expansion is used to approximate the non-linear pipeline network Weymouth flow equation. Then use the matrix form to model the natural gas network with non-pipe elements. On the basis of this model, the multiple linear regression equivalent model is derived to represent the multi-port gas network. Finally, based on the established gas network equivalent model, a two-way IEGS optimized scheduling strategy is proposed to minimize system operating costs and carbon emissions. The results show that the complexity of the model is significantly reduced without reducing the accuracy and robustness.