Simulation of Distributed Control System (DCS) Field Devices and I/O Modules for Power Generation Automation

Abstract

Over the last decade, Automation technologies give important changes in the power generation process. These changes have led to significant advancement in control technologies. The Distributed Control System (DCS) plays a role of brain for Automated power generation process to control number of parameters in order to increase the overall plant efficiency and stability. When the power generation process is large and the control aspects are complex, it is difficult to install DCS directly in real system. For this reason direct implementation or modernization of DCS in real systems requires big efforts and time investments. Sometime system implementation failure would result in the high asset, time and economical loss. However, the Simulation of actual Distributed Control System (DCS) is still missing. To overcome this problem, the work presented in this dissertation report is to model and simulate operational behaviours of a steam generator control system. The project methodology is to develop a PID control type model describing water level dynamics in the boiler drum of natural circulation type. Basic conservation rules, relevant loops and transfer functions in addition to key parameters (drum level, drum pressure, steam and water demand flow, control valve steam position, heat rate etc.) were incorporated in the model. Several assumptions were made and some operational parameters omitted to maximise the predictability of simulations. The current closed loop simulations model is presented as a solution. More generally, this study providing a simulation model that expands on existing knowledge on drum level behaviour and performance under varying operational conditions. The performance of simulated control system evaluated in terms of tracking capability, stability and robustness in simulation tool. The robustness of the proposed method against common disturbances and parameter variation has been investigated in this work. The results of simulation will be embedded and discussed in this thesis work.