Coordinated Optimization of Multi-Regional Integrated Energy Systems Leveraging Flexibility From District Heating Network

Abstract

High renewable energy penetration brings urgent accommodation challenges to power systems. Interconnected multi-regional integrated energy systems (MRIES) offer an effective solution via cross-energy and cross-spatial balancing. To fully exploit the inherent storage potential of the interconnected district heating network (DHN) within MRIES, this paper proposes a coordinated optimization framework for electricity-heat-hydrogen coupled MRIES. First, a unified scheduling model is established, which fully incorporates the operation constraints of multi-energy stations, cross-regional multi-energy interaction mechanisms, and the refined hydraulic and dynamic thermal models of DHN, to accurately characterize the inter-temporal thermal storage flexibility from pipeline heat transport delay and thermal inertia. To address the nonconvex bilinear terms introduced by variable flow and variable temperature (VF-VT) regulation, the McCormick envelope is adopted to realize convex relaxation, and a sequential bound tightening (SBT) algorithm is further developed to iteratively narrow the feasible range of variables, enhance the tightness of relaxation. Numerical results demonstrate that the proposed method can effectively leverage the flexibility of heating networks, and achieve significant advantages in both operational economy and renewable energy accommodation.