Optimal Energy Scheduling and Sensitivity Analysis for Integrated Power-Water-Heat Systems

TL;DR

This paper presents a novel optimization framework for integrated power-water-heat systems, improving efficiency and flexibility through a decomposed heuristic approach and sensitivity analysis of control modes.

Contribution

It formulates the OPWHF problem and develops an efficient heuristic solution, enabling joint optimization of interconnected energy networks with complex constraints.

Findings

The framework enhances operational flexibility and social welfare.

Water and heating networks act as virtual energy storage.

Temperature-based control is more effective for certain pipeline parameters.

Abstract

The conventionally independent power, water, and heating networks are becoming more tightly connected, which motivates their joint optimal energy scheduling to improve the overall efficiency of an integrated energy system. However, such a joint optimization is known as a challenging problem with complex network constraints and couplings of electric, hydraulic, and thermal models that are nonlinear and nonconvex. We formulate an optimal power-water-heat flow (OPWHF) problem and develop a computationally efficient heuristic to solve it. The proposed heuristic decomposes OPWHF into subproblems, which are iteratively solved via convex relaxation and convex-concave procedure. Simulation results validate that the proposed framework can improve operational flexibility and social welfare of the integrated system, wherein the water and heating networks respond as virtual energy storage to time-varying energy prices and solar photovoltaic generation. Moreover, we perform sensitivity analysis to compare two modes of heating network control: by flow rate and by temperature. Our results reveal that the latter is more effective for heating networks with a wider space of pipeline parameters.