Design and control of a variable ratio gearbox for distributed wind turbine systems

dc.contributor.advisorChen, Dongmei, Ph. D.en
dc.contributor.committeeMemberLongoria, Raul G.en
dc.contributor.committeeMemberMasada, Glenn Y.en
dc.contributor.committeeMemberPratap, Siddharth B.en
dc.contributor.committeeMemberTraver, Alfred E.en
dc.creatorHall, John Francis, 1968-en
dc.date.accessioned2012-10-11T21:07:37Zen
dc.date.accessioned2017-05-11T22:28:30Z
dc.date.available2012-10-11T21:07:37Zen
dc.date.available2017-05-11T22:28:30Z
dc.date.issued2012-08en
dc.date.submittedAugust 2012en
dc.date.updated2012-10-11T21:07:48Zen
dc.descriptiontexten
dc.description.abstractWind is one of the most promising resources in the renewable energy portfolio. Still, the cost of electrical power produced by small wind turbines impedes the use of this technology, which can otherwise provide power to millions of homes in rural regions worldwide. To encourage their use, small wind turbines must convert wind energy more effectively while avoiding increased equipment costs. A variable ratio gearbox (VRG) can provide this capability to the simple low-cost fixed-speed wind turbine through discrete operating speeds. The VRG concept is based upon mature technology taken from the automotive industry and is characterized by low cost and high reliability. A 100 kW model characterizes the benefits of integrating a VRG into a fixed-speed stall-regulated wind turbine system. Simulation results suggest it improves the efficiency of the fixed-speed turbine in the partial-load region and has the ability to limit power in the full-load region where pitch control is often used. To maximize electrical production, mechanical braking is applied during the normal operation of the wind turbine. A strategy is used to select gear ratios that produce torque slightly above the maximum amount the generator can accept while simultaneously applying the mechanical brake, so that full-load production may be realized over greater ranges of the wind speed. Dynamic programming is used to establish the VRG ratios and an optimal control design. This optimization strategy maximizes the energy production while insuring that the brake pads maintain a predetermined service life. In the final step of the research, a decision-making algorithm is developed to find the gears that emulate the ratios found in the optimal control design. The objective is to match the energy level as closely as possible, minimize the mass of the gears, and insure that tooth failure does not occur over the design life of the VRG. Recorded wind data of various wind classes is used to quantify the benefit of using the VRG. The results suggest that an optimized VRG design can increase wind energy production by roughly 10% at all of the sites in the study.en
dc.description.departmentMechanical Engineeringen
dc.format.mimetypeapplication/pdfen
dc.identifier.slug2152/ETD-UT-2012-08-6105en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2012-08-6105en
dc.language.isoengen
dc.subjectWind energy conversionen
dc.subjectVariable ratio gearboxen
dc.subjectGearbox developmenten
dc.subjectOptimal controlen
dc.subjectMultiobjective designen
dc.titleDesign and control of a variable ratio gearbox for distributed wind turbine systemsen
dc.type.genrethesisen

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