Real-time multiobjective optimization of operation of water supply systems

Abstract

The need for more efficient use of energy in water distribution systems is increasing constantly due to increasing energy prices. A new methodology for optimized real-time operation of a water distribution system is developed and presented here. The methodology is based on the integration of three models: (1) real-time demand forecasting model, (2) hydraulic simulation model of the system, and (3) optimization model. The optimization process is driven by the cost minimization of the energy used for pumping and the maximization of operational reliability. The latter is quantified using alternative measures into the optimization process in order to mimic the conservative attitude to pump scheduling often adopted by control room operators in real-life systems. Optimal pump schedules were generated by using a multialgorithmgenetically- adaptive-method (AMALGAM), hydraulic simulations are performed by using the EPANET2 model, and demand forecasting was performed by using the recently developed DAN2-H model. A number of other methodological developments are used to enable pump scheduling in real time. The new methodology is tested, verified, and demonstrated on the water distribution system of Araraquara, in the state of São Paulo, Brazil. The results obtained demonstrate that it is possible to achieve substantial energy cost savings (up to 13% relative to historical system operation) while simultaneously maintaining the level of supply reliability obtained by manually operating the water system.