Liquid Level Control of Separator in an OTEC Plant with Uehara Cycle Using Model Predictive Control

Abstract

This paper considers the liquid level control of separator in an ocean thermal energy conversion (OTEC) experimental plant with Uehara cycle. A liquid level model of separator constructed in previous studies is used, where the model was constructed based on the results of characteristic measurement experiments. This model includes system noise and observation noise to represent the unmodeled parts. In the conventional study, this model was used to design a control system that combined LQG control with a steady-state Kalman filter. However, it was not possible to take into account the physical constraints on the liquid level and valve opening. Therefore, this paper proposes a new control system design that combines model predictive control (MPC) with steady-state Kalman filter. The usefulness of the control system was confirmed through simulation.