In this thesis permanent magnet direct drive generator for power conversion from water currents is studied. Water currents as a power source involves a number of constrains as well as possibilities, especially when direct drive and permanent magnets are considered. The high power fluxes and low current velocities of a water current, in combination with its natural variations, will affect the way the generator is operated and, flowingly, the appearance of the generator. The work in this thesis can, thus, be categorized into two general topics, generator technology and optimization. Under the first topic, fundamental generator technology is used to increase the efficiency of a water current generator. Under the latter topic, water current generators are optimized to a specific environment. The conclusion drawn from this work is that it is possible to design very low speed direct drive generators with good electromagnetic properties and wide efficiency peak.
Contents
Acknowledgments
Introduction
The Resource
Tidal currents
Constant currents
Power Conversion
Design and simulation of electric machines
Method
Mathematical model of a generator
Geometry
Analysis
Summary of Papers
Generator Technology
Paper A: E. Segergren, B. Bolund, H. Bernhoff and M. Leijon, Rotor
Concept Comparison for Underwater Power Generation
Paper B: E. Segergren, K. Nilsson and M. Leijon, Frequency Optimisation With Respect to Weight and Electric Efficiency for
Direct Drive Underwater Power Generator
Paper C: E. Segergren and Mats Leijon, Relation Between Generator Geometry and Resistance in Armature Winding
Paper D: K. Nilsson, E. Segergren, and M. Leijon, Analysis of Low
Speed Permanent Magnetized Generators for use in Marine Current
Speed Permanent Magnetized Generators for use in Marine Current
Power Conversion Optimization
Paper E: K. Nilsson, E. Segergren, and M. Leijon, Simulation of Direct Drive Generators Designed for Underwater Vertical Axis
Turbines Paper F: E. Segergren, K. Nilsson, E. Sjöstedt, J. Sundberg and M.
Leijon, Converting Kinetic Energy in Water Currents Using Direct Drive Generators
Paper G: E. Segergren, K. Nilsson, D.P. Coiro and M. Leijon, Design
of a Very Low Speed PM Generator for the Patented KOBOLD Tidal Current Turbine
Paper H: B. Bolund, K. Thorburn, E. Sjöstedt, M. Eriksson, E.
Segergren and M. Leijon, Upgrading Generators with New Tools and
High Voltage Technology
Paper I: E. Segergren, K. Nilsson and M. Leijon, Permanent
Magnetized Generator for Marine Current Power Conversion – Proposed Experimental Setup
Paper J: Assembly comprising a Water Turbine and a Generator, the
Rotor of which is Direct-Connected to each one of the Blades the Turbine
Summary of Results and Discussion
Generator Technology
Optimization
Conclusions
Suggestions for Future Work
References
Author: Segergren, Erik
Source: Uppsala University Library
Download URL 2: Visit Now