Reliability Evaluation of Integrated Energy Systems Based on Exergy

The research on reliability evaluation of an integrated energy system (IES) is of great significance to system planning and operations. The differences of multiple energy subsystems must be considered in reliability evaluation of an IES, in which energy quality differences of various energy resources is critical. Current reliability evaluation of an IES cannot uniformly evaluate the reliability of multiple energy subsystems due to neglecting the energy quality differences of various energy resources. To address this problem, a novel reliability evaluation method for IESs based on exergy is proposed for the first time in this paper. The exergy of an energy resource or a substance is a measure of its usefulness, quality or potential to cause change. The models of exergy not supplied minimization and exergy efficiency maximization are proposed to alleviate energy capacity deficiency and transmission component overload in the reliability evaluation of an IES. These two models are compared to analyze exergy efficiency for the proposed method. The energy supply priority strategy of an IES is proposed considering energy quality differences of various energy resources, in which electricity, gas and heating/cooling subsystems are supplied in an orderly manner. Furthermore, a reliability evaluation indices system of an IES based on exergy is proposed in this paper. An extensive case study on an actual IES demonstrates the feasibility and effectiveness of the proposed reliability evaluation method.