Control strategies and wastewater treatment plants performance: Effect of controllers parameters variation

In this paper ten control strategies are tested, starting from a default tuning of the controllers, to evaluate its results in terms of general plant performance indicators such as the effluent quality index (EQI) and the operating cost index (OCI). Using the Benchmark simulation No 1 (BSM1), many simulations are done to determine the most sensitive parameter of the proportional-integral (PI) controllers implemented. The most sensitive parameter is selected by evaluating the influence of the proportional gain (K_p) and the integral time (T) in the general performance of the plant when they are changed into the proposed ranges. From the simulation study, Ti is selected as the most sensitive parameter. A comparison between the results in terms of EQI vs OCI graphics, varying K_p and Ti and the results varying only T_i, shows similar behaviours on the plant performance for all strategies.