High bandwidth generator |
NREL conducted a comparison of ten identical 10kW HAWT from a well known small wind manufacturer in different locations around Washington State. The best perfomance over a year of monitoring corresponded with the location having the greatest wind resource averaging in excess of 7m/s. The 10kW HAWT produced about 14,000 kWh/year operating only 17% of the time. With an $80,000 price tag and the value of power @ $.065/kWh the payback, absent subsidies and incentives, is 88 years. The narrow operating bandwidth of typical open bladed systems contributes to the intermittency problems seen throughout the centralized grid. A typical HAWT used in the average wind farm operates less than 30% of the time. A ducted fan design has the capability to convert wind to power at both lower and higher speeds than a HAWT only if the generator is also high bandwidth. Many of the original problems characterizing conventional energy sources associated with large electric power grid delivery remain for newer clean alternatives. The technology of generators in particular is essentially unchanged since early days in power technology, except for the addition of more powerful modern materials, such as Neodymium-Iron-Boron magnets, more capable modern metal alloys and fiber composite material. Generators today are in the main either electromagnetic field coil or high gauss permanent magnet inductively based machines, with significant quantities of transformer steel and copper. Such machines are complex and expensive to construct. Another type of generator also exists, the UNIPOLAR generator, based directly on the original FARADAY disc, circa 1829-1831. This early Lorentz law relativistic generator survives today in the modern UNIPOLAR generator with very low internal impedance and consequent very high current delivery, for applications such as in aluminum reduction plants. A very wide power bandwidth generator design is especially useful in wind turbine applications, where power in the wind is proportional to the cube of the velocity; a doubling of the velocity in the wind produces eight times the delivered electrical power. Integrating a ducted fan wind conversion system capable of operating in variable wind speeds with a wide power bandwidth generator increases the efficiency of the hybrid system significantly by increasing the operational percentage from less than 30% typical of traditional HAWT systems to more than 54% Radical new generator topologies and capabilities could make local micro grid wind powered utility systems not only possible but compellingly sensible. With an intrinsic potentially high power time base, as wind can occur 24/7, expensive additions to the existing large scale grid delivery system would not be required: power would be generated very near the point of power consumption, without any increase in local pollution or heat production. The V-LIM proprietary relativistic generator is scalable in sizes and radially or axially configurable. Additionally, the generator does not utilize wound coils and introduces a unique magnet topology that allows maximum guass from 1/5th less magnet than existing wind powered generators that should ultimately reduce the cost of manufacture. The generator has intrinsically very low internal impedance, and is thus potentially very efficient and can also be used as a motor in other applications including linear actuators, screw gear type motors, and right on through small instrument electrical motors, to landing gear extension and retraction motors, to various electrical solenoid switch type motors. |
