Optimal Scheduling of the Integrated Electricity and Natural Gas Systems Considering the Integrated Demand Response of Energy Hubs

Nowadays, integrated electricity and natural gas system (IENGS) stands as one of the most discussed topics among industry and academic sectors. The interdependency issues of electricity and natural gas may limit the operational flexibility of the IENGS and consequently prevent wind power integration. This article aims to solve the problem by incorporating the demand-side flexibility of energy hubs (EHs) into the scheduling of the IENGS. To fully exploit the demand-side flexibility, the detailed integrated demand response (IDR) model is developed for the EHs. Unlike the traditional demand response programs in which only elastic electricity demand is considered, both electricity demand and natural gas demand are considered flexible and controllable in the IDR. Moreover, the IDR is modeled as an optimization problem rather than a price-responsive load bid. The interactions between the EHs' IDR model and the IENGS's scheduling model are achieved based on the two-level optimization framework. Then, the IDR-embedded scheduling of the IENGS is formulated as a complicated two-level mixed integer nonlinear programming (TL-MINLP) problem. A technique is proposed to solve the TL-MINLP problem efficiently to enable the IDR-embedded scheduling model to be used in engineering practice. Case study illustrates the benefits of the proposed IDR-embedded scheduling method.