Testing the WET-NZ Wave Energy Converter Using the Ocean Sentinel Instrumentation Buoy

Abstract

This paper describes ocean testing of the half-scale Wave Energy Technology-New Zealand (WET-NZ) prototype wave energy converter (WEC) using the Ocean Sentinel instrumentation buoy during a 6-week deployment period in August‐October 2012. These tests were conducted by the Northwest National Marine Renewable Energy Center (NNMREC) at its Pacific Ocean test site off the coast of Newport, Oregon. The WET-NZ is the product of a research consortium between Callaghan Innovation, a New Zealand Crown Entity, and Power Projects Limited (PPL), a Wellington, New Zealand private company. The Oregon deployment was project managed by Northwest Energy Innovations (NWEI), a Portland, OR firm. NNMREC is a Department of Energy sponsored partnership between Oregon State University (OSU), the University of Washington (UW), and the National Renewable Energy Laboratory (NREL). The Ocean Sentinel instrumentation buoy is a 6-m surface buoy, developed in 2012, that provides a stand-alone electrical load, WEC generator control, and data collection for WECs being tested. The Ocean Sentinel was deployed and operated for the first time during the 2012 WET-NZ tests. During these tests, the operation of the WET-NZ was demonstrated and its performance was characterized, while also proving successful deployment and operation of the Ocean Sentinel.

Development and Wave Tank Demonstration of a Fully Controlled Permanent Magnet Drive for a Heaving Wave Energy Converter

“…Optimal values can be selected by advanced knowledge of the sea state and an accurate hydrodynamic model of the device. Alternatively, a simple representative control algorithm based on a 'cycling' maximum power point tracking algorithm (MPPT) [48,49] has been designed and implemented [25].…”

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“…This data was analyzed to characterize the output power P of the WET-NZ with respect to R dc . This analysis is described in [7]. The results showed that P was maximized when R dc was somewhere between about 10 Ω and 50 Ω over a wide range of sea states.…”

“…Characteristics of the device are listed in Table 1. The design of the WET-NZ and the 2012 Pacific Ocean tests are described in further detail in [7]. The Ocean Sentinel power conversion and control equipment was used to operate the WET-NZ throughout that deployment.…”

“…During the course of the 2012 half-scale WET-NZ WEC deployment with the Ocean Sentinel, which is described in detail in [7], NNMREC experimented with MPPT control of the WET-NZ using both the perturb and observe and the cycling MPPT algorithms. Both algorithms were used to control the WET-NZ generator load resistance R dc .…”

Wave Energy Research, Development and Testing Including Testing of Materials and Technologies for Bio-Fouling and Corrosion Prevention

“…The Ocean Sentinel power conversion, control, and data acquisition system (DAS) was used to control the load applied to the WET-NZ power take-off (PTO), and to collect WEC power and ocean data throughout the deployment period. This allowed experimentation with different control methods during the deployment; the results of these tests are described in [5]. 2013 Ocean Sentinel Deployment at the PMEC-NETS NNMREC deployed the Ocean Sentinel for the second time in July 2013 for a 9-week period to perform much needed mooring analysis and testing, which included numerical modeling and experimental validation.…”