Comparison of current control strategies applied to a boost-rectifier connected to a direct drive wave energy converter

Direct drive wave energy converters are characterized by a direct conversion of the wave energy into electricity with no intermediate mechanical conversion system. For this reason, optimization methods for maximizing the absorbed power have to be designed for acting on the electrical generator. Besides, this type of system requires power electronics to be connected to the grid. This paper evaluates three different current control strategies applied to a boost-rectifier in the ac-dc stage as part of an optimization method. The system is implemented and simulated in MATLAB/Simulink with real random waves. In direct drive wave energy conversion, unlike the original application of these controllers, the input electrical power is highly variable, both in amplitude and frequency. The controllers are assessed under these conditions and their advantages and disadvantages are presented.