Computer Assisted Control and Data Logging for a Reservoir Inlet System

This paper describes a computer based data logging and control system at the Preston Reservoir Control Centre. The computer assisted operation and control at Preston Reservoir provides the ability to manage higher operating pressures, optimise available transfer water from supply reservoirs (Morang and Winneke) and improve operating facilities in terms of efficiency and reliability. Functions performed automatically include proportioning of flow at the inlet to the three reservoirs in response to consumer demands in accordance with operator defined level or flow bands. The reservoir control algorithm caters for various modes of modulation in accordance with seasonal demands. Status information of valves, some of which are automatically sequenced by a programmable logic controller, is provided on the video display unit at the operator's console. The ability to monitor analog information, both locally and from remote sites (through telemetry) is included as well as the ability to access trend information in graphical form, and data stored on other nodes of the distributed processing network. Facilities have been included to operate mathematical models for operator guidance that are resident on other processors throughout the system. By utilising the facilities provided by the computer control and data logging system, programmable logic controller, analog controller and remote manual control, optimum use of available water is made. The system configuration allows for alternative modes of automatic and remote operation from the control room by implementation of a hierarchical control system configuration.