Modeling and control of a nonlinear electric power utility boiler system
The purpose of this research thesis is to develop a dynamic nonlinear model of CPS Energy‟s J.K. Spruce Unit 1 boiler and use several different techniques to develop controllers for boiler systems. One model will be based on characteristics of the boiler gathered from construction data and steam tables. The total drum water volume, Vwt, drum pressure, p, the quality at the riser outlet, fÑr, and the volume of steam under liquid level, Vsd, will be four states used based on physical parameters of the boiler system. This model will then be used to test its behavior given real-time data from J.K. Spruce Unit 1 in order to compare the performance and overall similarity of its state output to the actual states. The next goal of the thesis will be to develop a controller for a simplified model, previously developed in . This thesis will explore the design of a digital controller that drives the states to the desired values quicker. Lastly, this thesis will develop a linear parameter-varying system for intermediate system descriptions of the nonlinear model. These descriptions will be used to compute our controller inputs from linear matrix inequalities and to drive the nonlinear boiler model to the desired set-point. The designed controller will yield three control inputs: feedwater mass flow rate, qf, steam mass flow rate, qs, and the applied heat, Q.