Hydraulic and electric regulation of a prototype for real-time control of pressure and hydropower generation in a water distribution network

Coupling pressure management and energy recovery in water distribution networks (WDNs) is an appealing topic in the field of optimal management of water systems. The use of turbines or pumps as turbines (PATs) allows for reducing leakage within the network while also recovering energy that would otherwise dissipate, by means of pressure reducing valves (PRVs). Unlike water supply systems, where operating conditions remain essentially constant over time, a real-time control (RTC) is required in WDNs because of the variability of pressure and flow discharge during the day. To this end, a prototype for RTC of a WDN was presented and discussed in a recent paper, in which constant rotational speed of the impeller was considered. To overcome such a limitation and maximize energy recovery, an inverter was coupled to the prototype. A mathematical model of the prototype was developed and the decision variables were calculated by solving an optimization problem via the YALMIP tool of MATLAB at varying conditions of inflow discharge, pressure head at the inlet, and desired pressure head at the control node. The mathematical model was further validated through preliminary laboratory experiments, showing good agreement between simulated and actual values.