Recovery Act - High Torque, Low Cost, Direct-Drive Rotary Generator
Small Business Information
Columbia Power Technologies, Llc
236 East High Street, Charlottesville, VA, 22902
AbstractColumbia Power has identified a highly-effective wave energy converter that efficiently converts wave motion into rotary motion for conversion to electric power. Prior research by Columbia Power has identified that a power take off (PTO) utilizing rotary direct drive electric generation will provide a cost advantage over other PTO alternatives. The specifications for this direct-drive rotary generator are not satisfied by any existing commercial product, thus a research, design, and demonstration effort is required in order to minimize the commercial risks of developing such a machine. The required direct-drive rotary PTO specifications include high torque, high efficiency, a low friction marine bearing/seal solution, long life in a marine environment, high bearing loads, and a cost effective design.Phase I of the research included electromagnetic modeling, and design investigations of a permanent magnet rotary generator design which incorporates high efficiency, high torque, and a small-air-gap design that prioritizes low material and manufacturing costs. By taking advantage of the low speed (<1rpm), certain mechanical design advantages are exploited in order to reduce the electromagnetic machine air gap; additionally, the machine diameter is increased in order to increase air-gap velocity. The combined improvements will each provide a linear reduction in cost and allow for cost reductions and the potential for a feasible generator design Research was conducted to select the best machine design topology, optimize its design and propose a path forward for phase II demonstration. The project necessitated the development of a sophisticated genetic algorithm (GA), designed to optimize cost of energy, which also aided in the selection of key design parameters. This GA approach reduced modeling time and consistently converged to low-cost design solutions, which resulted in the proposed testing of a sectional piece of the full-scale machine.This project will design, build and test an angular section of a full-scale machine. The test will confirm numerical modeling estimates, test the proposed bearing design, and develop a full-scale design. The fullscale design will be used as the basis for a comprehensive cost evaluation to confirm feasibility. Commercial Applications and Other Benefits: Low speed and high torque is a common characteristic for the prime mover of renewable energy sources such as wind, tidal, and wave energy. These systems will benefit from a cost-effective rotary generator solution. If the electromagnetic and interface design concepts proposed in this project can be implemented in a cost effective way, significant cost reductions will be realized for these renewable energy systems. This Phase II project will allow for the necessary proof of concept that will allow for the full-scale build of a machine for Columbia Power
* information listed above is at the time of submission.