SCADA: Simulator

Simulation Of SCADA

Simple simulation of a SCADA system with Java Applet can be used for controlling a small water supply system. In the system there are water wells or bores that pump water to a storage tank. In case the storage tank is large for supplying to a town using its gravity, a transfer pump station pumps water to it. For still larger town, systems with more zones are required but the principle remains the same as for a small town. Only in case of very large cities, the water supply system is divided into many zones but still working with same guiding principle.

Applet Menu

There is a menu bar at the bottom of the applet with options “start”, “stop”, “inhibit”, and “summer”, “autumn”, “spring” and “winter”. The use of first two options is obvious. The “inhibit” option is clicked to slow down operation of all bores and pumps when the electricity supply goes through peak tariff periods. The water supply system in this mode can be operated quite safely during winter, autumn and spring. But use of inhibit mode in summer would result in the town running out of water supply. The times when the pumps are inhibited are indicated by a display during the running of the simulation. To select between different demands situations according to seasons, the last four options as mentioned above are used. This Java simulation applet is programmed for a screen size of at least 800x600. The applet needs quite an updated version of Netscape (at least 4.07) or IE4. JDK 1.1.6 is also used in this application.

Schematic Representation

The level in the storage tank controls the two “banks” the bores are organized into. With falling tank level, bank 1 starts functioning. Further fall drives bank 2 to commence work. The storage tank is provided with a display named “Tank RTU” that indicates the time of calling bank 1 or 2 by the RTU. Finer control strategies than this simulation is adopted in real situations.