A weighted local steady-state determination approach based on the globally optimal economic steady-states

Steady-state incremental constraints of manipulated variables play a vital role in making given steady-states satisfy physical limitations and avoiding drastic set-point changes. Nevertheless, some research reveals that the steady-state incremental constraints will make the given locally optimal economic steady-states diverge from the globally optimal economic steady-states. Therefore, a novel weighted local steady-state determination approach based on the globally optimal economic steady-states is presented in this paper. Firstly, the globally and locally optimal economic steady-states are both evaluated through considering and not considering steady-state incremental constraints. Then, the angle between them is evaluated and the closest local steady-state from the globally optimal economic steady-state is calculated. Subsequently, a new weighted local steady-state is evaluated by combining the locally optimal economic steady-state and the closest local steady-state, in which the weighting coefficient is carefully tuned based on the above-calculated angle. Finally, several simulations verify that the proposed method could effectively shorten the settling time of controlled systems and improve their economic performance