Global stabilization of chemical reactors with classical PI control (Q2730968)

The problem of nonlocal stabilization of nonlinear continuous stirred tank reactors (CSTR) by output feedback with the widely used proportional plus integral (PI) controllers is analyzed. By exploiting the structure of CSTR models and using recent results on stability of nonlinear singularly perturbed systems, it is shown that global asymptotic stabilization of CSTR can be achieved by a high proportional plus low integral temperature compensation. It is also proved (under mild and realistic assumptions) that if the isothermal dynamics is globally asymptotically stable then the classical PI temperature controller guarantees global stability of nonlinear CSTR dynamics. This fact meets the continual sympathy of practical engineering for PI feedback in CSTR temperature regulation.