A constrained tuning approach for optimal pump operation

Abstract

Water supply systems transport drinking water from a treatment plant and make it available to users’ taps. The main concern in the operation of a water supply system is to guarantee consumer demands under a choice of quantity and quality throughout the entire life span for the possible loading circumstances. However, in some circumstances, the present infrastructure may not be adequate to meet the customer’s requirements. In such a scenario, system modelling plays a significant role in suitable management of water supply systems. From the perspective of taking management decisions, valve throttling control and pump speed control are very significant. These operational complications can be addressed by manual control or by automatic control. The difficulty is the use of manual controls that bring down the efficiency of the system. An automatic control–based skill has been developed that links the process of the variable speed pump control or valve throttling control. By employing an automatic control, the pump can regulate its speed at all times to meet the real flow requirements of each load served. A pump operational policy is established by which all the reservoirs can be fed concurrently to meet their requirements without making excessive transients. The gain of non-linear controllers is tuned by using different tuning methods such as the Ziegler-Nichols and constraint tuning and the best tuning method estimated. A significant additional objective was developed, namely, the search of optimal pump speed using the Monte Carlo method.

Keywords:

• water supply system
• level control
• non-linear controller
• ziegle-nichols and constraint tuning
• monte carlo method

Acknowledgement

This article belongs to the selected papers presented at the ‘Hydro-2012’ conference held at I I T Bombay on December 7-8, 2012 and short-listed by Editor for publication in this Journal after re-review and revisions where necessary.