An extensive assessment on the rural village of Ga-Rampuru was conducted. There are plenty of recyclable materials including old milling machines that are not in use. These materials can be recycled to clean Ga-Rampuru village.
Rural artisans who can assemble the wind turbine
Since there are many local artisans who fix cars, electrical appliances and do some mechanical work in this village, manpower should not a problem. An engineer from the government or Non-governmental organization could educate these local artisans on assembling the wind generator. This will have a positive impact on Ga-Rampuru village as it will encourage people to work and be creative. There are many old wind mills used for pumping water in Ga-Rampuru village, most of these wind mills are working perfectly well supplying sufficient water. This is a clear indication that there is a reliable supply of wind in the village.
Simulation results
It has been shown that a reasonable amount of power can be realised from a generator using recycled magnets from the dumpsites
Cost involved in the design
The overall cost of assembling this wind generator system will be very cost effective since all the materials are recycled from the village, and the entire system will be assembled by local artisans.
Validity of this thesis
Small power that can turn on small lamps will really be appreciated in this village as children will be able to study after sunset. This will clearly have a wide range of positive developmental benefits on this community.
Chapter 8. Recommendations
Based on the above conclusions, the following recommendations were drawn:
1. For a more accurate recyclable wind turbine design, all its components such as the drum, the tower, rotor disk and cables must be explored in depth. The following must be considered:
· Investigate how to extract maximum power from the wind using the drum, and how to prevent the drum from over spinning.
· How to use other irregular recyclable magnets in the village in the generator design.
2. Investigate how a permanent magnet generator topology can be changed or re-designed to accommodate the design of a generator with the shape of the loudspeaker magnets.
3. Look in to how the magnets can be removed from the speakers, since very strong clue is used to mount them, how this can be done in a cost effective way.
4. The axial flux permanent magnet topology should also be looked into to compare it to the radial flux type.
5. The exact costs of assembling and maintaining the recycled wind turbine should also be incorporated in the design procedure.
6. With the little output power generated in this thesis, this project must definitely be taken further to alleviate the electricity problems in South Africa.
References
1. Socio-economic rights project, “The right to affordable electricity” copyright @ community law centre 2002
2. IDASA, http://www.idasa.org.za
3. Department of Minerals and Energy, White Paper on the Renewable Energy Policy of the Republic of South Africa. August 2002
4. Department of Minerals and Energy, White Paper on the Renewable Energy Policy of the Republic of South Africa. November 2003
5. Sathyajith Mathew, “Wind Energy-Fundamentals, Resource Analysis and Economics ” © Springer- Verlag Berlin Heidelberg 2006
6. Smail Khennas, Simon Dunnett and Hugh Piggott, “Small wind systems for rural energy services”. ITDG Publishing 2003
7. Kevin Reeves, “The design and Implementation of a 6kW wind turbine simulator” University Of Cape Town, South Africa, Oct 2004
8. FrequentlyAskedQuestions http://www.magnetsales.com/Design/FAQs_frames/FAQs_2.htm © 2000 Magnet Sales & Manufacturing Company, Inc
9. R.C. Bansal, T.S. Bhatti, D.P. Kothari, “On some of the design aspect of wind energy conversion systems” Birla Institute of technology and science, Pilani, September 2002
10. Jacek F. Gieras, Mitchell Wing, “Permanent magnet motor technology-Design and Applications” 1st edition. Marcei Dekker, Inc. 1997
11. Prof E. J. Odendal, “Design, construction and testing of a small wind generator with electronic controller for domestic use”. University of Natal, Durban
12. Jacek F. Gieras, Mitchell Wing, “Permanent magnet motor technology-Design and Applications” 2nd edition. Marcei Dekker, Inc. 1997
13. P.C. Sen, “Principles of electric machines and power electronics” 2nd edition. John Wiley & Sons
14. Bhag S. Guru, Huseyin R. Hiziroglu, “Electric Machinery and Transformers” 3rd edition. Oxford University Press, Inc. 2001
15. Dr. James Livingston, “Magnetic Materials Overview”
16. E. Muljadi, C.P. Butterfield, Yih-Huei Wan, “Axial flux, Modulator, Permanent-Magnet with a Toroidal winding for wind turbine applications”. Cole Boulevard, Nov 1998
17. Magfag, 2003 by Force Field
18. M.A. Khan, P. Pillay, “Design of a PM wind generator, optimised for energy capture over a wide operating range”
19. Joe Naylor, “Speakers with Alnico magnets vs. speakers with ceramic magnets”
20. Hybrid (Wind/Solar/LP Gas) Systems for Rural Community Development, “Electrifying South Africa for prosperity and development”. Upper Maphaphethe by Mike Wintherden
21. Danish Wind Industry Association, ‘Guided Tour’ online htt://windpower.org/en/tour/wres/betz.htm
22. Lysen, E.H., ‘Introduction to Wind Energy’ CWD,2nd edition, p.p 51-73
23. Ripinga Nonkululeko, “Comparison of grid and off-grid rural electrification, based on the actual installation in Limpopo Province”. University of Cape Town, Oct. 2005
24. Alfred Still & Charles S. Siskind, “Elements of electrical machine design”. 3rd edition. McGraw-Hill Book company,inc. 1954
Appendix A
Graphs of output rms induced voltage and flux of the generator
1. Commercial Standard Magnets
a) Ceramic FLux_RMS = 0.0175
EMF_RMS = 3.6075
b) Alnico FLux_RMS =0.0168
EMF_RMS = 5.1619
c) NdFeB FLux_RMS = 0.0459
EMF_RMS = 9.4262
2. Loud Speaker Magnet
FLux_RMS = 0.0171
EMF_RMS = 3.4987
Appendix B
Matlab code for sketching the output emf and flux of the generators
% EMF calculation from FEMM
%By Maribini Manyage
clc
clear all; close all;
P = 2;
w = 1912; %mechanical speed in rpm
freq = (w*pi/30)*P/(4*pi); %frequency
XA = load('flux_link_A.txt');
XB = load('flux_link_B.txt');
XC = load('flux_link_C.txt');
beta = XA(:,1); % angle between Is_r and d-axis [elec degrees]
alpha = beta - beta(1,1); % Rotor position in [elec degrees] from Zero
time = alpha*(pi/180)/(2*pi*freq);%*1000; %time
flux_link_A = 2*XA(:,2);
flux_link_B = 2*XB(:,2);
flux_link_C = 2*XC(:,2);
% Perform spline in order to differentiate flux linkage vs time
pp_flux_A = spline(time,flux_link_A);
pp_flux_B = spline(time,flux_link_B);
pp_flux_C = spline(time,flux_link_C);
% extracting piecewise polynomial coefficients and derivation
[hgt,wdth] = size(pp_flux_A.coefs);
clear AA;
for k = 1:hgt
AA(k,:) = polyder(pp_flux_A.coefs(k,:));
end
dpp_flux_A = MKPP(time,AA)
[hgt,wdth] = size(pp_flux_B.coefs);
clear AA;
for k = 1:hgt
AA(k,:) = polyder(pp_flux_B.coefs(k,:));
end
dpp_flux_B = MKPP(time,AA);
[hgt,wdth] = size(pp_flux_C.coefs);
clear AA;
for k = 1:hgt
AA(k,:) = polyder(pp_flux_C.coefs(k,:));
end
dpp_flux_C = MKPP(time,AA);
%back emf
emf_A = ppval(time,dpp_flux_A);
emf_B = ppval(time,dpp_flux_B);
emf_C = ppval(time,dpp_flux_C);
figure(1);
plot(time*1000,flux_link_A,'r-');
hold on;
plot(time*1000, flux_link_B,'b-');
plot(time*1000, flux_link_C,'g-');
title('Flux linkage - under noload');
xlabel('Time [ms]'),ylabel('Flux linkage [WbT]')
grid;
figure(2);
plot(time*1000,emf_A,'r-');
hold on;
plot(time*1000, emf_B,'b-');
plot(time*1000, emf_C,'g-');
title('Back Emf - under noload');
xlabel('Time [ms]'),ylabel('Back EMF [V]')
grid;
x = length(flux_link_A);
FLux_RMS = norm(flux_link_A)/sqrt(x)
y = length(emf_A);
EMF_RMS = norm(emf_A)/sqrt(y)
Дата: 2019-07-24, просмотров: 156.
