A new control scheme for improving the performance of pressure reducing valves in water distribution networks
The use of pressure control to reduce leakage is well known. The benefit is significantly increased if pressures are controlled in response to changes in demand or flow. To achieve this, it is necessary to enable the pressure controller to sense both flows and the corresponding pressures, thereby avoiding unnecessarily high system pressures. In the implementation of a pressure management scheme for leakage reduction, both steady state and dynamic aspects should be considered. The steady state aspects ensure that the set-points of a pressure reducing valve (PRV) are changed according to an optimal profile so as to minimize background leakage and to satisfy pressure requirements at critical points. The dynamic aspects ensure that excessive pressure changes (oscillations) caused by interactions between modulating valves and transients in water networks are not generated across the distribution networks. This paper will focus on the dynamic aspects of pressure control. A new control scheme is presented to achieve fully flow modulated dynamic pressure control. The proposed controller is based essentially on a PRV dynamic model, and the flow modulated pressure control is achieved using both pressure and flow information. Computer simulations are carried out to illustrate the operation and performance of the new controller. The simulation results show that the performance of the resulting PRV for pressure regulation is comparable with that of a recently proposed PID controlled PRV. The new scheme simplifies the controller design process and also gives better performance for flow modulated pressure control.
Citation : Li, P., Prempain, E., Postlethwaite, I. and Ulanicki, B. (2009) A new control scheme for improving the performance of pressure reducing valves in water distribution networks. The 8th International Conference on Hydroinformatics, Concepción, Chile, 12-16 January 2009.
Research Group : Centre for Engineering Science and Advanced Systems
Peer Reviewed : Yes