This book presents the papers given at a workshop on wind turbines. Topics considered at the workshop included aerodynamics, load conditions, Darrieus rotors, composite materials, turbine blades, fabrication, fiberglass, vibrations, wind power plants, control systems, data acquisition systems, performance testing, horizontal axis turbines, vertical axis turbines, tornado turbines, electric generators, and wind turbine arrays.

Wind energy systems

Optimization of wind farm turbines layout using an evolutive algorithm

Site matching of wind turbine generators is investigated based on the appropriate selection of statistical models and means of wind speed data. The wind speed means are computed using arithmetic mean, root mean square and cubic mean cuberoot. Wind speed frequency distributions are modelled using Weibull and Rayleigh probability density functions. Wind speed data of an existing wind power station, located at Kappadagudda, Karnataka, India, is used for computational purposes. The analytically obtained capacity factors are validated by comparing with the actual capacity factors obtained at Kappadagudda. It is observed that the capacity factors computed from the Weibull statistical model using cubic mean of wind speed data fairly match the actual capacity factors obtained from Kappadagudda wind power station. Various commercially available wind turbine generators are used for site matching studies. The model described in the paper is useful for planning of wind power stations as it can be applied for the accurate assessment of wind power potential at a site.

Site matching of wind turbine generators: a case study

On some of the design aspects of wind energy conversion systems

Direct methods for studying dynamics of large-scale electric power systems-A survey

Long term wind records are used to select the rated wind speed for wind electric generators. The wind is characterized by a Weibull dencity function. Detailed results are presented for western Kansas. Graphs are presented which can be used to design a wind system for maximum specific output for a specified load factor at a given site. It is shown that a wind turbine rated at a wind speed of 9 m/s has a specific output within 80% of the maximum for a wide range of wind conditions.

Economic Design of Wind Electric Systems

A new measure of the relative transient stability of a multimachine power system based on the Lyapunov stability theory is introduced. Techniques of sensitivity analysis are used to determine numerically the influence of variations or errors in the estimation of the system parameters on the transient stability of a power system. In particular, data is presented for an application of these ideas to a one machine infinite bus system.

New Stability Measure for Multimachine Power Systems

Two statistical distributions are fitted to a set of extreme wind data and the Fisher-Tippett Type I is shown to be superior. Daily extremes are examined for their influence on wind turbine operation. Formulas are given for converting annual extreme wind statistics to daily or monthly extremes. A daily extreme of 40 mph is experienced about 1 day out of 10 and 56 mph about 1 day out of 100 at 50 m in Kansas.

Distributions of Daily Extreme Winds and Wind Turbine Operation

Design details are given for a laboratory instrument which will measure real and reactive power using Hall effect transducers. The basic theory of these transducers is presented. Examples of transient operation are given. One particularly interesting result is the variation in real and reactive power to an induction machine as it makes the transition between motor and generator.

Hall Effect Measurement of Real and Reactive Power in a Faraday Machines Laboratory

The work of three leaders in the search for a new energy source, spanning a full century, is examined. Nikola Tesla, T. Henry Moray, and Thomas E. Bearden, among others, have claimed the existence of another source of energy besides those presently in use. This source is the energy contained in apparently empty space. The concepts of each of the three are discussed. >

Gary L. Johnson

Papers

Economic Design of Wind Electric Systems

New Stability Measure for Multimachine Power Systems

Distributions of Daily Extreme Winds and Wind Turbine Operation

Hall Effect Measurement of Real and Reactive Power in a Faraday Machines Laboratory

Searchers for a new energy source: Tesla, Moray, and Bearden