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## Grid-tie inverter cooperating with renewable energy sources used for voltage quality improvement

### Łukasz Rosłaniec

#### Abstract

The PhD thesis focuses on two very important and up-to-date problems observed in electric power system. The first is rapid growth of dispersed generation unit capacity factor, which is mainly based on unstable renewable energy sources. This growth is a cause for problems with maintaining parameters of electric power at receivers terminals. Second important problem is growth of capacity factor of receivers which cause problems with maintain electric power quality. It is not only the reactive power flow which concerns power engineering staff, but even more distortions present in current flow caused by nonlinear receivers which are commonly observed in electric power system nowadays. The system was designed and targeted for linear receivers therefore it is observed that multiple problems of higher harmonics conduction are affecting it. The is a simple technical way of dealing with electric power quality issues which is modernization of system infrastructure. But this solution is costly and it also far from distributed energy sources are targeted for. Author in his research proposed that the distributed energy sources could be used for power quality improvement and therefore could lead to better utilization of founds used for generation units construction. Elimination of the problems in closest proximity to the place of their origin meaning distribution network can lead to further advantages in the power system. To do so series of test indicating possibility of the VSI to take part in power quality improvement was run. PhD thesis was aimed at construction of single-phase grid-tie voltage-source inverter which will transmit power from renewable energy sources to electric power system which is able to: •control its active and reactive power •partial compensation of distortions present in the PCC voltage •partial compensation of distortions in current caused by receivers connected in close proximity to the inverter •off grid operation in case of backup source operation The aim of the research was formulated in the following thesis: It is possible for a renewable energy source equipped with a storage system to participate in frequency control and to improve voltage quality by means of an inverter controlled by proper algorithm. The thesis describes proposed idea in following parts: •An overview of the possible ways of power transmission from distributed energy sources to the electric power system. •Description of problems which are present in the system because of renewable energy sources capacity factor growth with comparison to the standard power generation techniques. •Description of proposed unit concept. •Simulations and experimental tests indicating possibility of the proposed unit use to generate power to the electric power system. •The test of inverter use for electric power quality improvement in the point of common coupling (simulation and experiments). •Validation if the proposed technique is applicable to the standard topologies of inverters. •Conclusions.
Record ID
WUTcbfdba8d2d004b8aaf4006217ed33d00
Diploma type
Doctor of Philosophy
Author
Title in Polish
Falownik sprzęgający odnawialne źródło energii z systemem elektroenergetycznym, umożliwiający poprawę jakości napięcia
Title in English
Grid-tie inverter cooperating with renewable energy sources used for voltage quality improvement
Language
(en) English
Certifying Unit
Faculty of Electrical Engineering (FoEE)
Discipline
electronic engineering / (technology domain) / (technological sciences)
Status
Finished
Start date
13-10-2010
Defense Date
03-07-2014
Title date
17-09-2014
Supervisor
Antoni Dmowski Antoni Dmowski,, The Institute of Electrical Power Engineering (FoEE/IEPE)Faculty of Electrical Engineering (FoEE)
Internal reviewers
External reviewers
Benysek Grzegorz Benysek Grzegorz,, External affiliation of publication: Uniwersytet Zielonogórski
Honored
yes
Pages
151
Keywords in English
electric power engineering, power electronics
Abstract in English
The PhD thesis focuses on two very important and up-to-date problems observed in electric power system. The first is rapid growth of dispersed generation unit capacity factor, which is mainly based on unstable renewable energy sources. This growth is a cause for problems with maintaining parameters of electric power at receivers terminals. Second important problem is growth of capacity factor of receivers which cause problems with maintain electric power quality. It is not only the reactive power flow which concerns power engineering staff, but even more distortions present in current flow caused by nonlinear receivers which are commonly observed in electric power system nowadays. The system was designed and targeted for linear receivers therefore it is observed that multiple problems of higher harmonics conduction are affecting it. The is a simple technical way of dealing with electric power quality issues which is modernization of system infrastructure. But this solution is costly and it also far from distributed energy sources are targeted for. Author in his research proposed that the distributed energy sources could be used for power quality improvement and therefore could lead to better utilization of founds used for generation units construction. Elimination of the problems in closest proximity to the place of their origin meaning distribution network can lead to further advantages in the power system. To do so series of test indicating possibility of the VSI to take part in power quality improvement was run. PhD thesis was aimed at construction of single-phase grid-tie voltage-source inverter which will transmit power from renewable energy sources to electric power system which is able to: •control its active and reactive power •partial compensation of distortions present in the PCC voltage •partial compensation of distortions in current caused by receivers connected in close proximity to the inverter •off grid operation in case of backup source operation The aim of the research was formulated in the following thesis: It is possible for a renewable energy source equipped with a storage system to participate in frequency control and to improve voltage quality by means of an inverter controlled by proper algorithm. The thesis describes proposed idea in following parts: •An overview of the possible ways of power transmission from distributed energy sources to the electric power system. •Description of problems which are present in the system because of renewable energy sources capacity factor growth with comparison to the standard power generation techniques. •Description of proposed unit concept. •Simulations and experimental tests indicating possibility of the proposed unit use to generate power to the electric power system. •The test of inverter use for electric power quality improvement in the point of common coupling (simulation and experiments). •Validation if the proposed technique is applicable to the standard topologies of inverters. •Conclusions.
PKT classification
430000
KBN classification
34
Thesis file
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Uniform Resource Identifier
https://repo.pw.edu.pl/info/phd/WUTcbfdba8d2d004b8aaf4006217ed33d00/
URN
urn:pw-repo:WUTcbfdba8d2d004b8aaf4006217ed33d00

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