Application of Expert System and SCADA Technology to Operating Water/Wastewater Systems

The Water Board is a statutory authority set up in New South Wales to supply water, sewage, sewage treatment as well as storm water services to the people of Metropolitan Sydney and surrounding districts. The Board's area of activities is broken up into S regions. This paper is based on the work done in the lllawarra region of the Board. The Water Board's new IICATS SCADA system will give the users of the Board's assets a far greater control capacity than they have at the present time. As a part of the user requirements of the IICATS project it was identified that a new control philosophy was required. The new philosophy would control the assets on a system basis not on the asset by asset basis as is presently done. In developing control strategies and algorithms', it was soon recognised that they would have to be verified numerically by model simulation. This was required to improve the level of confidence in the proposed rules prior to their application to the water and wastewater systems via the IICATS SCADA. Initial simulation work was done using the Board's traditional hydraulic modelling package in combination with Lotus 123. This proved to be extremely time consuming and labour intensive. It was decided that an expert system modelling tool be investigated. The expert system shell 'G2' was chosen because of its design for real time applications and subsequent suitability for modelling and simulation. It provided a much more efficient simulation tool and enabled the Board to test its proposed system operations strategies. This led to improvements and fine tuning of the rules and increased operator confidence in the proposed control strategies prior to their implementation on the IICATS. During this initial phase of work with expert systems for operational application, several possible future developments have been identified. These include; the integration of G2 with the operating IICATS to provide operator advice, 'what if modelling, fault diagnosis, analysis of signal quality, and the development of hydraulic modelling capabilities within the 'G2' shell. The development of the G2 expert system shell for the simulation and verification of operational rules proposed for the lllawarra IICATS Project has proved a success. It has also opened the door for development of further applications throughout the Sydney Water Board.