Robustified optimal control of a coal-fired power plant

Abstract

This paper proposes the design of an advanced control technique to improve the control performances of industrial plants. Indeed, classical industrial solutions are typically based on SISO loops including classical PID controllers. This control strategy can clearly be improved. The solution proposed here is not to remove the industrial solution but instead to update it with additional loop(s), which is preferred in industry. As a first step, the desired optimal behavior is reached using a nominal linear model of the plant and LMIs in control. Then, if necessary, this controller is further off-line robustified towards unstructured and polytopic uncertainties within a second additional loop, also leading to LMI and possibly BMI formulations. This method is finally applied to a coalfired power plant, with an uncertain large delay as particular feature. The obtained simulation results are most satisfactory, the optimal behavior being kept while easily robustified for a very large range of delay values.