ADMM-Based Distributed Planning Model for Integrated Electricity and Natural Gas System

The regional integrated energy system (RIES), which couples multi-energy devices, energy storage systems, and renewable energy sources, is considered a promising solution for meetinhg future energy demands. A critical challenge in this domain is the planning for the expansion of existing natural gas and electricity networks, determining the optimal locations for RIESs, and selecting appropriate device types and capacities. Traditional joint planning models often overlook the fact that investment decisions are typically made by different stakeholders, each with their own ownership interests. In this study, we propose a novel distributed planning model that decomposes the joint planning problem into three subproblems, each corresponding to a different stakeholder. To solve these subproblems in a coordinated manner, we employ the alternating direction method of multipliers (ADMM). The effectiveness of the proposed model is validated using an updated IEEE 24-bus electric system, the Belgian 20-node natural gas system, and three assumed RIES. Simulation results illustrate that the distributed planning model is more responsive to individual load variations. Moreover, we further analyze the algorithm's performance, focusing on convergence rates and the effects of penalty parameters.