Rule extraction and optimization of fuzzy controllers in maximizing the captured power of wave energy converters

Abstract

In recent years, the extraction of electrical energy from sea waves has been considered by researchers due to its advantages such as renewability and high amount of extracted energy, and in recent research studies, several scientific solutions have been presented to maximize the energy obtained from these converters. One of the major problems that is ignored in most articles is the existence of several uncertainties that occur as an uncertain parameter in the proposed models for various types of wave energy absorbers, including mechanical parts erosion, limescale deposition and algae on buoyant which causes it to change weight. Ignoring these uncertainties will reduce the accuracy of the controller performance. Therefore, in this paper, for the first time, a fuzzy control process with optimized extracted rules and parameters is applied to control the damper and spring coefficients of the mechanical model describing a power takeoff system, which not only uses fuzzy control properties but also covers uncertainties. Optimizing the number of rules and structure of membership functions provides acceptable controllable accuracy and speed as it is mentioned in simulation results.