Nonlinear Controller and Estimator Design for Multi-Pump Systems

In this paper the nonlinear dynamics of a pressure boosting system consisting of multiple parallel centrifugal pumps, a pressure accumulator and a connected load are modeled. The modeling focus is on detailed component descriptions and their dynamical coupling, mainly introduced by the parallel connected pumps. Based on the model, a controller based on Input-Output Linearization is designed to decouple the outputs. Furthermore, an Extended Kalman Filter including the hydraulic dynamics is implemented to overcome the necessity of flow and pressure measurements. Therefore, the combined control scheme only interacts with the variable-speed drive. The functionality of the proposed control algorithm is proved by a test bench implementation.