A multi-stage joint expansion planning of transmission system and integrated electrical, heating, and cooling distribution systems-A security perspective

This paper proposes a joint multi-stage expansion planning approach for a comprehensive structure that integrates the Transmission System (TS) with electrical, heating, and cooling Distribution Systems (DSs), incorporating a security perspective. The security of both the TS and Integrated DSs is modeled by accounting for the potential failures in TS lines, electrical feeders, heating and cooling pipelines, and Demand Side Resources (DSRs). A three-level iterative approach, based on the diagonalization algorithm, is used to structure the problem. In the first level, the Transmission Expansion Planning (TEP) problem is formulated. The second level addresses the integrated Distribution Expansion Planning (DEP), while the third level involves market clearing and the updating of Locational Marginal Prices (LMPs) by the Independent System Operator (ISO). The related uncertainties such as the output of RESs, market prices, and load demands are addressed using a stochastic framework. This framework employs Monte Carlo simulation for scenario generation and the k-medoids methodology as an effective scenario reduction technique. The proposed model optimizes the total installation, operation, emission, and Expected Energy Not Served (EENS) costs for both the Transmission System Operator (TSO) and Distribution System Operators (DSOs). Numerical studies are conducted on the modified 30-bus, and 118 bus IEEE TS systems comprising 18 bus and 30 bus integrated electrical, heating, and cooling DSs, respectively. on the 30-bus IEEE TS and 18-bus IDSs to demonstrate the effectiveness of the proposed approach in reducing the total system cost by 17.78 % compared to the separate expansion planning of TS and IDSs.