A SYSTEM FOR SIMULATION, MONITORING AND DIAGNOSIS OF CONTROLLED CONTINUOUS-PROCESSES WITH SLOW DYNAMICS

This paper presents a modelling approach specifically designed to be u sed in a monitoring and diagnosis system based on the simulation of re levant process and control system variables. The model is based on sem antically extended data flow diagrams with each computational process representing the incremental behaviour of a component of the plant to be modelled. Variable as well as delay time behaviour is associated wi th each component model to support an event-driven simulation which, i n turn, reduces computation time. This plant model of independent but interacting computational processes is easily extendable, modifiable a nd adjustable according to changes in the plant. The modelling approac h is applied to a coal power plant process and is implemented in G2, a n object-oriented, real-time expert system shell with built-in simulat ion and online external connection capabilities. Generic rules guiding the event-driven simulation and monitoring allow for modular adaptati on of the model as the plant's structure and functionality change with out requiring changes in the rule set. (C) 1997 Elsevier Science B.V.