Interconnection strategies of point absorber type wave energy converters and rectifier units

Abstract

Direct-driven point absorber type tubular wave energy converters, reflect the random nature of wave energy input to its output voltage waveform. The better conditions in the generator output stage are the first step that allows the reduction in the need of complicated power conversion system. This work presents the preliminary analysis and comparison of two important interconnection strategies of WEC-rectifier units. Two different interconnection strategies are considered based on how they build up the DC-link, i.e. parallel (well- known and used by many researchers in wave area) and cascaded (less considered) configuration of WEC-rectifier units. Conventional two-level AC/DC/AC power conversion system is used in both cases. Matlab/Simulink based system simulation is used to compare the different interconnection strategies. Various results are presented and discussed, together with the voltage ripple calculations of the DC-link voltage and output phase voltage and current, being it important for the sizing and the cost of the system.