Delay-Dependent Stability analysis for nonlinearly perturbed and parametric uncertain heat exchanger system with time varying-delay

Abstract

Delay-dependent stability of network-controlled temperature control system (with feedback loop delay in the presence of time varying delays, exogenous load disturbance and parametric uncertainties) had been chosen as a task and the system was investigated by theoretical analysis. The Lyapunov-Krasovskii functional technique, expressed in LMI framework based stability criteria was used as a tool in this research. The inevitable time-delays, unknown exogenous load disturbance and parametric uncertainty are affecting the state evolution of the proposed system. The load disturbance temperature control was mathematically modeled as norm-bounded, nonlinear time varying function of current and delayed state vectors. The parametric uncertainty was modeled by using Taylor series expansion. Then, the parameters were incorporated into the delay-dependent stability analisys. In addition to the minimal number of decision variables, tighter bound integral inequality, using reciprocal convex combination lemma was employed in the analysis to obtain less conservative stability criteria. The results obtained are in accordance with the theoretically obtained in the heat exchanger and they are closer to the standard benchmark temperature-control of heat exchanger system.