Alphonse Schacher

Comparison of Direct-Drive Power Takeoff Systems for Ocean Wave Energy Applications

This paper presents a comprehensive power takeoff (PTO) analysis program conducted as a collaborative research effort between Columbia Power Technologies, Inc., Oregon State University (OSU), and the U.S. Navy. Eighteen different direct-drive technologies were evaluated analytically and down-selected to five promising designs. Each of the five prototypes was simulated, modeled in SolidWorks, and built at the 200-W peak level and tested on OSUs wave energy linear test bed. The simulations were validated with the 200-W experimental results and then scaled up to 100 kW, with full 100-kW designs including costs, maintenance, operations, etc., to estimate the cost of energy (COE) for each PTO buoy system at utility scale.

Maximum Power Point Tracking for Ocean Wave Energy Conversion

Many forms of renewable energy exist in the worlds oceans, with ocean wave energy showing great potential. However, the ocean environment presents many challenges for cost-effective renewable energy conversion, including optimal control of a wave energy converter (WEC). This paper presents a maximum power point tracking (MPPT) algorithm for control of a point absorber WEC. The algorithm and testing hardware are presented in detail, as well as simulated and laboratory test results. The results show that MPPT applied to ocean wave energy is an effective and promising control strategy.

A novel maximum power point tracking algorithm for ocean wave energy devices

Many forms of renewable energy exist in the worlds oceans, with ocean wave energy showing great potential. However, the ocean environment presents many challenges for cost-effective renewable energy conversion, including optimal control of a Wave Energy Converter (WEC). This paper presents a novel maximum power point tracking (MPPT) algorithm for control of a point absorber WEC. The algorithm and control hardware are presented in detail, as well as ocean and laboratory test results. The results show that MPPT applied to ocean wave energy is an effective and promising control strategy.

Novel Control Design for a Wave Energy Generator

This paper presents the derivation of a novel control method for a permanent magnet linear generator for use in wave energy applications. The control design is an extension of optimal wave energy converter (WEC) control theory. Adaptations have been made to account for a variety of real-world limitations. Dynamic generator loading is used to control the motion of the WEC. The novel control presented maximizes power output while also protecting the WEC system.

Scaled Development of a Novel Wave Energy Converter Including Numerical Analysis and High-Resolution Tank Testing

This paper presents the scaled development of a novel point absorber wave energy converter (WEC) developed by Columbia Power Technologies (COLUMBIA POWER, Corvallis, OR, USA), including numerical analysis and scaled wave tank testing. Four hydrodynamic modeling tools are employed to evaluate and optimize the performance of the WEC, including WAMIT, Garrad Hassans GH WaveDyne, OrcaFlex, and ANSYS AQWA. Performance and mooring estimates at full scale are evaluated and optimized, followed by the development of 1 : 33, 1 : 15, and 1 : 7 scale physical models. The physical tests of the 1 : 33 and 1 : 15 scale WECs were conducted in the wave basins of Oregon State Universitys O.H. Hinsdale Wave Research Laboratory, in conjunction with the Northwest National Marine Renewable Energy Center (NNMREC). This paper concludes with the development of the 1 : 7 scale WEC and the associated field testing.

Scaled development of a novel Wave Energy Converter through wave tank to utility-scale laboratory testing

This paper presents the scaled development of a novel point absorber Wave Energy Converter (WEC) developed by Columbia Power Technologies, Inc. (CPwr), including scaled wave tank testing to utility-scale laboratory testing. The scaled development and testing of 1:33, 1:15 and 1:7 scale physical models are discussed. The physical tests of the 1:33 and 1:15 scale WECs were conducted in the wave basins of Oregon State Universitys O.H. Hinsdale Wave Research Laboratory, in conjunction with the Northwest National Marine Renewable Energy Center (NNMREC). The 1:7 scale WEC was field tested for 13 months in Puget Sound, WA. This paper concludes with the development of the utility-scale WEC and the associated laboratory testing on the National Renewable Energy Laboratory (NREL) Wind Technology Center dynamometer test bed.

IEEE standards for oscillating machines to advance direct-drive wave energy generators

The objective of this paper is to present the need for IEEE standards for oscillating machines employed in wave energy generators. Due to the oscillating motion of ocean waves, the wave energy generator profiles are highly non-periodic and stochastic. Currently there are no IEEE or IEC standards for these types of oscillating machines, and thus critical questions remain unanswered such as the nameplate ratings and efficiencies that should be targeted for cost effective operation. Oscillating operation in an ocean environment is presented in the paper including real-world speed, torque, and output power testing data from an ocean wave energy generator. Related standards are discussed to illustrate that the duty types are not suitable to describe and represent the oscillating motion of wave energy generators. The paper concludes with an example utility-scale wave energy converter (WEC) design including the demanding cyclic operating conditions, and then presents required standards.

Direct drive ocean wave energy electric plant design methodology

Conversion of power from ocean waves requires power take off systems which are designed to accommodate a wide range of power variations. Power smoothing has traditionally been designed into the primary mechanical power conversion process. With a direct drive design, power smoothing is achieved by power electronics. The following paper presents a comprehensive analysis of the system requirements and design philosophy for the electric plant of a direct drive ocean wave energy converter (WEC). Annual real seas data was used to model power flow from rotary Permanent Magnet Generators (PMG) through the electric plant to the grid. Component pricing and site specific wave climates are incorporated into simulations to guide the electric plant design development. The results of these simulations provide design recommendations on WEC electric plant configuration and component specification for the lowest capital cost and high energy production.

Direct Drive Wave Energy Buoy – 33rd scale experiment

Columbia Power Technologies (ColPwr) and Oregon State University (OSU) jointly conducted a series of tests in the Tsunami Wave Basin (TWB) at the O.H. Hinsdale Wave Research Laboratory (HWRL). These tests were run between November 2010 and February 2011. Models at 33rd scale representing Columbia Power’s Manta series Wave Energy Converter (WEC) were moored in configurations of one, three and five WEC arrays, with both regular waves and irregular seas generated. The primary research interest of ColPwr is the characterization of WEC response. The WEC response will be investigated with respect to power performance, range of motion and generator torque/speed statistics. The experimental results will be used to validate a numerical model. The primary research interests of OSU include an investigation into the effects of the WEC arrays on the near- and far-field wave propagation. This report focuses on the characterization of the response of a single WEC in isolation. To facilitate understanding of the commercial scale WEC, results will be presented as full scale equivalents.