Abstract

Subject of the present thesis is the study of the acoustic noise of a locally manufactured small wind turbine and the effect of current harmonics that are created by the use of uncontrolled diode bridge rectifiers in battery connected applications.

An introduction is made on the principles of Renewable Energy Sources, wind energy and on the tools that allow us to exploit it, wind turbines. Also the definition of sound is presented and its relation with the human ear.

Then, a literature review is made for the meaning of noise, the origin of noise in machines and in more detail in wind turbines, while ways of noise reduction are presented. Alongside, the effects of noise are indicated in human health and three-phase rectifiers, current harmonics and cutoff filters for current harmonics are studied.

The IEC 61400.11 standard is presented and the procedures defined for the recording and analysis of the noise emission of a wind turbine.

Further on, acoustic measurements in the lab are performed for a generator connected to a three phase ohmic load, to a battery connected generator and to a battery connected generator with the use of a harmonic notch filter. At the same time recording of the current harmonics is performed.

Based on the IEC 61400.11 standard, acoustic noise measurements are performed on a locally manufactured small wind turbine in the field and the results are compared with the results of the laboratory experiment.

Finally conclusions are drawn and proposals for improvements and further work are suggested.

Key words: renewable energy sources, wind energy, small wind turbines, sound, noise, noise pollution, acoustic measurements, current harmonics, cutoff filters for current harmonics

Author: Alexis Mantazkos

Responsible PhD: Kostas Latoufis / latoufis@power.ece.ntua.gr

Supervising Professor: Nikos Hatziargyriou / nh@power.ece.ntua.gr

PDF: Full version (Greek) and Short version (English)