Event-Triggered Nonlinear Control of OWC Ocean Wave Energy Plant

This paper presents event-triggered nonlinear controllers for oscillating water column (OWC) ocean wave energy plant. The study is based on event-triggered backstepping controller (ET-BSC) and event-triggered sliding mode controller (ET-SMC) to control the rotational speed of an OWC turbine coupled to a generator. The designed controllers are capable to avoid the stalling of the Wells turbine so as to maximize its output power. The aim of event-triggered control is to minimize the control updates, thus providing efficient utilization of resources without compromising the OWC performance. In this regard, aperiodic sampling has been applied using an event-triggering rule derived from Lyapunov stability analysis. In order to validate the proposed controllers, simulation results have been performed using a JONSWAP irregular wave model. It is observed that performance of the ET-BSC is better than the ET-SMC in terms of defined indices, control effort, and inter-event execution time.