Discrete-Time Sliding Mode Spatial Control of Advanced Heavy Water Reactor

Abstract

This brief presents the design of a discrete-time sliding mode control (DSMC) for spatial power stabilization of advanced heavy water reactor (AHWR). Mathematical model of AHWR is represented by 90 first-order nonlinear differential equations with 18 outputs and five inputs. The linear model is obtained by linearizing nonlinear equations over the rated power. This linear model is found to be highly ill conditioned and is possessing three-time-scale property. Initially, the linear model is transformed into block diagonal form to separate slow, fast 1, and fast 2 subsystems and then DSMC is designed using slow subsystem alone since fast 1 and fast 2 subsystems are stable. The proposed DSMC strategy is designed using the constant plus proportional rate reaching law with matched disturbance. Finally, the nonlinear multivariable model of AHWR is simulated with the designed controller and the results are generated under different transients. The efficacy of the proposed DSMC is demonstrated with the comparison of prevalent controllers in the literature and the performance is evaluated under the same transient levels.