Experimental Performance Evaluation of a Hydraulic PTO System for Centipede Wave Energy Converter

In the past decade, ocean and marine waves like other renewable energy sources attracted attention due to its high energy density. The most important part of a wave energy converter (WEC) is power take-off (PTO) system. In this study, a proper hydraulic power take-off system for centipede WECs has been evaluated and analyzed in experimental scale. Experimental analysis has been done in dry conditions. Important parameters are resistant load of rheostats and the opening percent of the flow control valve. System input is the wave force, which is modeled as an external mechanical force applied to the end of the lever. Resistant load of rheostats is changeable in the range of 9.5 to 55 ohms. In addition, according to the range of valve opening, six positions are selected to study. Results in this research show that, as resistance load increases, output power and efficiency, are enhanced significantly. On the other hand, in all the resistive loads tested, there is a maximum point (2 rev. valve opening) for efficiency, which shows the positive effect of controlling the input flow to the Hydro Motor (HM). The efficiency in this position of the flow control valve opening has enhanced by 40% compared to neighbor situations.