High dynamic speed control of the Subsea Smart Electrical Actuator for a Gas Production System

The next revolution of the subsea gas production system is the replacement of traditional hydraulic devices with all-electronic ones. The hydraulics and spring system that is typically used to close the valve in an emergency is gradually abandoned, and as one of the promising candidates, the smart electrical actuator has attained tremendous attention. The utilization of high-efficient permanent magnet synchronous motor (PMSM) provides more flexibilities and faster response in operating the valve and therefore is much preferred in this application. This paper proposes a high dynamic speed control strategy for subsea smart electrical actuators (SMAs), which comprises a direct torque control for the inner loop and a sliding mode control (SMC)-based speed regulator in the outer loop. In a combination of these two techniques, the system dynamics can be remarkably improved. A comparative study between the proposed SMC and the previous methods, including the classical PI controller and the former SMC, is carried out through the simulation, where the advantages of the presented method are confirmed.