Integrated energy system security region: Concepts, methods, and implementations

The interconnection and coupling of integrated energy systems (IES) including electricity system, natural gas system and district heating system become increasingly tight. It brings opportunities for improving energy consumption efficiency as well as challenges on security interactions. Thus, the concepts of the IES security region (SR), which considers all the essential operational constraints of IES (including voltage magnitude constraint, thermal constraint, gas pressure constraint, gas transmission constraint, and temperature constraint), are discussed in this paper. These concepts stem from the ideas of power system security regions and are expanded to the multi-dimensional IES involving the limits and parameters of electricity, natural gas, and district heating networks. A set of optimization models are developed to explore the SR boundaries (SRBs) in the IES. Also, a piecewise approximation is proposed to represent the SRB of IES in a multi-dimensional space with a minimum set of hyperplanes. After that, the potential implementations of SR for security assessment and optimal control in the IES are presented and analyzed. Numerical results from the IES 30-20-2 x 6 system demonstrates the feasibility and effectiveness of the proposed method and verifies that it can significantly enhance the situation awareness ability of the IES.

Automated summary

This paper discusses the concept of security regions (SR) in integrated energy systems (IES), develops optimization models to explore SR boundaries, proposes a piecewise approximation method to represent SRBs in a multi-dimensional space with a minimum set of hyperplanes, and explores potential implementations of SR for security assessment and optimal control in the IES.