Abstract:

In the desulphurization control system of units No.3 and No.4 in Guangdong Zhuhai Jinwan Power Generation Company Limited, the Foxboro I/A Series

distributed control system is adopted. The off-line and restarting phenomenon of single or double controllers in system occurred randomly, which threatens

the safe and stable operation of the unit severely. The synchronous records of the system management counter and the controller were analyzed to determine

the network problem; the node bus network had been monitored, and the data streams between stations were analyzed. It was determined finally that the data

acquisition and send program of the supervisory information system in plant level, Opifox, caused the congestion of the node bus network of desulphurization

distributed control system, which makes the two controllers to be asynchronous and to start up again. The data acquisition and send program had been

replaced, and at last, the difficult problem was solved.

Key words: distributed control system (DCS), controller restarting, supervisory information system (SIS) in plant level, Opifox, node bus