Optimalno sledenje fotonapetostnega sistema soncu ob upoštevanju izgub pogonskega sklopa

doktorska disertacija

Sebastijan Seme (Author), Gorazd Štumberger (Mentor), Jože Voršič (Co-mentor)

Abstract

Doktorska disertacija obravnava optimalno sledenje fotonapetostnega sistema soncu, pri čemer upoštevamo električne izgube pogonskega sklopa. Sledenje fotonapetostnega sistema soncu omogoča, da pri tem na sončne module pade čim več razpoložljive energije sončnega sevanja. Pogonski sklop, ki omogoča sledenje, predstavlja za fotonapetostni sistem porabo električne energije. Idealni izplen pretvorbe razpoložljive energije sončnega sevanja bi bil dosežen ob zveznem sledenju sledilnega sistema poti sonca. Ker imajo pogonski sklopi konstantno hitrost in diskreten način sledenja, se lahko idealnemu izplenu energije sončnega sevanja le približajo. V doktorski disertaciji je predstavljeno, kako diskretno slediti poti sonca, da na sončne module pade čimveč razpoložljive energije sončnega sevanja, pri čemer so upoštevane električne izgube pogonskega sklopa. Za dosego želenega cilja so potrebne čim bolj natančne vrednosti o razpoložljivi energiji sončnega sevanja pri tleh v danem trenutku. Zato je v okviru doktorske disertacije razvit model za napoved celotnega in difuznega sončnega sevanja v obliki časovno odvisne funkcije za jasne dni. Model je potrjen s primerjavo med izmerjenim in napovedanim sončnim sevanjem za jasne dni. Napoved sončnega sevanja v obliki časovno odvisne funkcije in izgube pogonskih sklopov, kot funkcije naklona in azimuta, so uporabljeni za določitev optimalnih trajektorij sledilnega sistema. Za iskanje rešitve nelinearnega in omejenega problema je uporabljena stohastična metoda, imenovana Diferenčna evolucija. Tovrstni pristop za iskanje maksimalnega izplena fotonapetostnega sistema še ni bil raziskan v nobeni literaturi. Uporablja se točno določena kriterijska funkcija, ki je minimalna v optimizacijskem postopku glede na optimizacijske meje. S tem je zagotovljena največja možna pretvorba energije sončnega sevanja, upoštevajoč uporabljen model fotonapetostnega sistema, porabe sledilnega sistema, napovedi sončnega sevanja in lastnosti optimizacijskega postopka. Uporaba drugačnih in bolj naprednih modelov fotonapetostnega sistema, porabe sledilnega sistema ali napovedi sončnega sevanja lahko privede tudi do drugačnih optimalnih trajektorij sledilnega sistema. Vendar to nikakor ne zmanjša teže predlagane metode. Predlagana metoda daje maksimalni izplen fotonapetostnega sistema za uporabljene modele in podatke.

Keywords

fotonapetostni sistemi;sledilni sistemi;pogonski sklop;

Data

Language:	Slovenian
Year of publishing:	2011
Source:	Maribor
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FERI - Faculty of Electrical Engineering and Computer Science
Publisher:	[S. Seme]
UDC:	621.383.5:621.311.243(043.3)
COBISS:	14925078
Views:	2617
Downloads:	458
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	Optimal sun-tracking of a photovoltaic system considering the electric drive losses
Secondary abstract:	Doctoral thesis deals with optimal sun-tracking of a photovoltaic system considering the electric drive losses. The Sun tracking PV system assures that the highest possible share of the available solar radiation reaches the surface of the PV modules. The electric drive which enables tracking is considered as the loss of the energy produced in the PV system. The maximum of the energy produced in the PV system is achieved by the continuous tracking of the PV system. Since the electric drives are determined by constant speed and time, and angle quantization the maximum of the energy produced can only approximate. The doctoral thesis presents a new method for determining such trajectories of the PV modules that change the position of the PV modules in such a way that the production of the electric energy in the given time interval of the observation reaches its maximum. The goal is to determine the maximum efficiency of the PV tracking system considering the tracking system energy consumption. To achieve this, exact values of the available solar energy are needed for a given moment. To do this, a new method for predicting direct and diffuse solar radiation on the Earthćs surface, in the form of the time dependent function, is developed. The method is confirmed by the comparison of the measured and the predicted solar radiation for clear days. The developed method for predicting the solar radiation in the form of the time dependent function and energy consumption of the tracking system, given as the functions of the azimuth and tilt angle change, are applied together to determine those trajectories of the PV module, where the PV system energy production, gives the maximum. To find a solution of the nonlinear and bounded optimization problem, a stochastic search algorithm called DifferentialEvolution is applied. The approach for determining the maximum of the energy produced in the PV system has not been researched yet. The explicitly defined objective function, which is minimized in the optimization procedure considering the optimization bounds, is used. Thus it is assured the maximum of the possible energy produced in the PV system, considering the applied model of the PV system, tracking system consumption, predicted solar radiation, and the properties of the applied optimization method. The use of the different and more advanced models of the PV system, the sun tracking system consumption or prediction of the solar radiation, can lead to the different optimal trajectories of the sun tracking system. However, this cannot reduce the importance of the proposed method. The proposed method gives the maximum of the possible energy produced in the discussed PV system, considering the applied models and data.
Secondary keywords:	photovoltaic system;tracking system;electric drive;optimization;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. v Mariboru, Fak. za elektrotehniko, računalništvo in informatiko
Pages:	XIII, 125 str.
Keywords (UDC):	applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;engineering;technology in general;inženirstvo;tehnologija na splošno;mechanical engineering in general;nuclear technology;electrical engineering;machinery;strojništvo;electrical engineering;elektrotehnika;applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;engineering;technology in general;inženirstvo;tehnologija na splošno;mechanical engineering in general;nuclear technology;electrical engineering;machinery;strojništvo;electrical engineering;elektrotehnika;
ID:	1014099