93 - Economic Model Predictive Control of Water Distribution Systems with Accelerated Optimization Algorithm

Water distribution systems (WDSs) are complex systems that involve interconnected hydraulic elements (e.g., pipes, storage tanks, pumps, and valves) to transport water from the sources to the consumers. Given that WDSs are regarded as one of the critical infrastructures, providing optimal control of WDSs is crucial to ensure high-quality delivery and reliable service to consumers. Model predictive control (MPC) has emerged as an effective strategy for WDSs' management. However, it is hampered by the computational burden for large-scale WDSs due to the combinatorial growth of possible control actions that must be evaluated at each time step. Therefore, a fast computation algorithm to implement MPC in WDSs can be obtained using a move-blocking approach. The basic idea is to reduce the control degrees of freedom (DoF) over the prediction horizon to improve solution tractability while still meeting the objectives. However, conventional move-blocking is overly rigid. Therefore, this paper proposes a least-restrictive move-blocking through interpolated delta input blocking. The proposed approach maintains the feasibility of the solution while retaining the computational benefits. The proposed control strategy is demonstrated on aggregated WDSs, encompassing multiple hydraulic elements, thus controlling a multiple input and multiple output (MIMO) system. This implementation is incorporated into a multi-objective optimization framework that concurrently optimizes water level security of the storage tanks, smoothness of the control actions, and cost-effective objectives. A fair comparison between the proposed approach with different move-blocking strategies and with the non-blocking Economic MPC is provided.