Modeling and nonlinear model predictive control of a subsea pump station

Abstract

In this paper we present a model of a pump station consisting of two pumps in parallel with a recycle line, and a nonlinear Model Predictive Control strategy for said pump station with suction pressure as the controlled variable. The dynamics of the flow through the pump station is described using slightly modified models previously presented for electrical submersible pumps. By using the symbolic framework CasADi in Matlab, we solve the nonlinear optimal control problem by first discretizing it using the single shooting method and then solving the finite-horizon nonlinear program. Simulations in Simulink shows that the proposed solution is able to track the suction pressure reference under various conditions and disturbances, while respecting constraints.