Sequential Convex Program for Variable Speed Pump Scheduling in Water Distribution Systems

Abstract

Operation of water distribution systems (WDSs) to reduction of water leakage can be achieved by properly operating variable speed pumps (VSPs). This practical problem can be casted into a nonlinear program (NLP) where decision variables are relative speeds of pumps while the state variables are flows and nodal heads. The formulated NLP consists of both convex and non-convex constraints, for this reason, we proposed to apply the sequential convex programming technique (SCP) for solving the NLP. The advantage of the SCP method lies in the fact that instead of solving the non-convex NLP, we solve sequential convex NLPs and, in this case, it requires less number of iterates for solution convergence than solving the problem directly by using standard NLP solvers. The effectiveness of the approach was demonstrated on two WDSs for optimal VSP scheduling problem