To see the other types of publications on this topic, follow the link: Shunt active power filters.
Dissertations / Theses on the topic 'Shunt active power filters'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Shunt active power filters.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Yiauw, K. H. "An investigation of shunt active power filters." Thesis, Swansea University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636711.
Full textAbstract:
Electrical power quality has grown from obscurity to a major issue due to the wide use of non-linear power electronic loads in many applications. Passive filters have been extensively used to prevent harmonics from entering the power system. However, there are many disadvantages and hence active power filters provide an alternative solution to the passive filters. Active power filters have the advantages over the passive filters such as low cost, smaller physical size and are able to compensate for randomly varying harmonic currents. In this thesis, Shunt active power filters have been employed for harmonic current and reactive power compensation for typical non-linear loads. The characteristics of active power filters have been discussed and the operation modes of both single-phase and three-phase active power filters have been documented. The proposed APF system is based on voltage-source current-controlled PWM converter topology, and uses two separate controllers, namely current control loop (CCL) and voltage control loop (VCL). CCL deals with the supply current using a PI controller for current harmonic reduction by injecting the required amount of harmonic current components with equal in magnitude but opposite in polarity to the utility to cancel the harmonic currents produced by the non-linear power electronics load. The VCL is based on sliding mode (SLMC) control, it served two purposes: it regulates and maintains the DC capacitor voltage at a constant level and provides the feedback information for the reference current. The design of the proposed active power filter system has been carried out using ORCAD PSPICE simulation software package. The contribution of this research work is in-depth investigation of the shunt active power filter for supply current harmonics reduction and reactive power compensation, the current waveform is maintained sinusoidal and in phase with the supply voltage for a given non-linear load so as to improve the power factor. The current information is extracted using the supply current detection method and the voltage source current controlled PWM converter is employed to extract the voltage information required for the APF action. The simulation and practical results are discussed and conclusion drawn.
2
El-Habrouk, Mohamed. "A new configuration for shunt active power filters." Thesis, Brunel University, 1998. http://bura.brunel.ac.uk/handle/2438/5241.
Full textAbstract:
This thesis presents a new power circuit configuration to be used in shunt active power filters. A new control algorithm based on the linear voltage control suitable for the proposed circuit is introduced. The system is analysed both in time and frequency domains. The practical implementation of the system proves its suitability for the proposed task. The switching frequency of the proposed circuit is much lower than that in other active filters. The switching losses are then considerably reduced, in addition to the fact that the switching devices can withstand larger values of currents being switched on and off at lower frequencies which is an advantage to this circuit. The component sizes (capacitors and inductors) in the proposed circuit are also much smaller than those in other filter configurations. In addition, the thesis presents a new method for categorising the active filter systems proposed in the surveyed literature. The survey includes a comparison of these techniques showing their respective merits and drawbacks. The thesis also includes an implementation of a reference current generator that is suitable for single-phase applications without the need for excessive computations. The technique involves a modified Fourier analysis, which is suitable for active filtering applications.
3
Gray, Matthew Alan. "A comparative analysis of proportional-integral compensated shunt active power filters." Master's thesis, Mississippi State : Mississippi State University, 2004. http://library.msstate.edu/etd/show.asp?etd=etd-11092004-083404.
Full text
4
Lavopa, Elisabetta. "A novel control technique for active shunt power filters for aircraft applications." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/12049/.
Full textAbstract:
The More Electric Aircraft is a technological trend in modern aerospace industry to increasingly use electrical power on board the aircraft in place of mechanical, hydraulic and pneumatic power to drive aircraft subsystems. This brings major changes to the aircraft electrical system, increasing the complexity of the network topology together with stability and power quality issues. Shunt active power filters are a viable solution for power quality enhancement, in order to comply with the standard recommendations. The aircraft electrical system is characterized by variable supply frequency in the range 360-900Hz, hence the harmonic components occur at high and variable frequencies, compared to the terrestrial 50/60Hz systems. In this kind of system, fast and accurate algorithms for the detection of the reference signal for the active filter control and robust high-bandwidth control techniques are needed, in order for the active filter to perform the harmonic elimination successfully. In this thesis, two novel algorithms are proposed. The first algorithm is a frequency and harmonic detection technique, particularly suitable for tracking the variable supply frequency and the harmonic components of voltages and currents in the aircraft electrical system. Complete identication of the reference signal for the active filter control is possible when applying this technique. The second algorithm is a control technique based on the use of multiple rotating reference frames. Only the measurement of the voltage at the Point of Common Coupling and the active filter output current are needed, hence no current sensors are required on the distorting loads. Both the techniques have been validated by means of simulation and experimental analysis. The results show that the proposed methods are effective for a successful harmonic compensation by means of active shunt filters, in the More Electric Aircraft environment.
5
Gous, Marthinus Gerhardus Faculin. "Shunt active power filtering algorithms for unbalanced, non-linear loads." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53589.
Full textAbstract:
Thesis (MScEng)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: This thesis presents the design and implementation of shunt active power filtering algorithms for unbalanced, non-linear loads. A three-phase four-wire topology is developed in the dqO space. Based on this development an accurate dynamic system model, taking into account the effect of the neutral inductor is developed. The synchronous reference frame technique is expanded to enable the isolation of the zero sequence current component into its instantaneous active and reactive current components. Additionally a prediction method is proposed that will enable the proper prediction of the reference currents in a threephase four-wire system. Two categories of reference current signal tracking algorithms are investigated; namely the predictive current controller and the sliding mode current controller. A compensating technique is proposed to compensate for the effects that sampling and computational time delay have on the performance of the system. Additionally, an investigation is done into the effect that dead-time has on the performance of the system, and based on this investigation a dead-time compensating strategy is proposed. Finally simulation and practical results are provided to validate the discussed theories.
AFRIKAANSE OPSOMMING: Hierdie verhandeling ondersoek die ontwerp en implementering van parralel gekoppelde aktiewe filter algoritmes vir ongebalenseerde, nie-lineêre laste. 'n Drie-fase vier-draad topologie, asook 'n korrekte model van die dinamiese sisteem, wat die effek van die neutraal induktor insluit, is ontwikkel in die dqO ruimte. Die sinchroon verwysing vlak tegniek is uitgebrei om die isolering van die nul sekwensie stroom in onderskeidelik die oombliklike aktiewe en reaktiewe stroom komponente te verdeel. Addisioneel is a vooruitskatting tegniek aanbeveel wat die beheerder in staat sal stelom voldoende die verwysing strome vooruit te skat in 'n drie-fase vier-draad stelsel. Twee katagoriee van verwysing stroom volging algoritmes is ondersoek, naamlik die afskatting stroom beheerder en die gleiende modus stroom beheerder. 'n Effektiewe kompensasie tegniek is voorgestel om die effek van tydvertraging as gevolg van monstering en verwerking te elimineer. Addisioneel is die effek van dooie-tyd ondersoek en gebasseer op hierdie ondersoek is 'n effektiewe dooie-tyd kompensasie tegniek voorgestel. Laastens is simulasies en praktiese resultate verskaf om die werking van die voorgestelde teorie te bevestig.
6
Van, Greunen Corneluis Erasmus. "Neutral-point-clamped shunt active filter." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1265.
Full text
7
Sedighy, Mohammad. "A robust VSC-based shunt active power filter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0002/NQ41307.pdf.
Full text
8
Carastro, Fabio. "Power quality enhancement using a shunt active filter with energy storage." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493118.
Full textAbstract:
Electrical systems are subject to a wide variety of power quality problems which can interrupt production processes, affect sensitive equipment, and cause downtime. Several power quality studies show that harmonics and voltage sags have been identified as the most serious problems facing industrial customers today, especially in small independent grids which employ distributed generation units.
9
Massoud, Ahmed Mohammed. "Application of the cascaded multilevel inverter as a shunt active power filter." Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/321.
Full text
10
Zhang, Huibin. "Application of multilevel inverter as shunt active power filter in three-phase three-wire power system." Thesis, University of Strathclyde, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501797.
Full textAbstract:
This research investigates application issues of the active power filter to three-phase three-wire systems, with unbalanced, distorted loads where the line impedance gives rise to voltage distortion at the point of common coupling. Five shunt active power filters are investigated: two-level, wye connected cascaded three and five level, and diode-clamped three and five level. Capabilities of the different shunt active power filter topologies to mitigate voltage/current distortion, compensate reactive power, and balance real power from the source are investigated. Results indicate that neutral point clamped multilevel inverters have advantages over wye cascaded multilevel inverters when operating under asymmetrical load conditions.
11
Gomes, Zariff Meira. "Filtro Ativo Trifásico Shunt com Número Reduzido de Indutores." Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/7552.
Full textAbstract:
Submitted by Maria Suzana Diniz (msuzanad@hotmail.com) on 2015-11-05T13:46:16Z
No. of bitstreams: 1
arquivototal.PDF: 4508623 bytes, checksum: 8e1affd5d5c342bcac7e265720885b0c (MD5)Made available in DSpace on 2015-11-05T13:46:16Z (GMT). No. of bitstreams: 1 arquivototal.PDF: 4508623 bytes, checksum: 8e1affd5d5c342bcac7e265720885b0c (MD5) Previous issue date: 2015-07-24
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This work presents an active power filter for three-phase three-wire systems without an inductor when compared to the usual structure of a shunt active power filter. For the determination and control of the references it was used the Park’s transformation, it means that all control was done in synchronous axes. The active filter of this work is in parallel configuration acting therefore as a current source and should correct the power factor and current harmonics selectively of the power grid. Simulation results were presented validating the control strategy.
Neste trabalho é apresentado um filtro ativo de potência trifásico para sistemas a trifásicos a três fios com um indutor a menos em comparação com a estrutura usual de um filtro ativo shunt. Para a determinação das referências e controle foi utilizada a transformada de Park, ou seja, todo o controle foi feito em eixos síncronos. O filtro ativo deste trabalho está na configuração paralela funcionando, portanto, como uma fonte de corrente e deverá corrigir o fator de potência e harmônicos de corrente da rede elétrica, estes últimos de forma seletiva. Foram apresentados resultados de simulação validando a estratégia de controle.
12
Pahmer, Sueda Carmen M. "Contribution à l'étude de filtres actifs de puissance de type shunt : commande-simulation." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0080.
Full textAbstract:
Le travail presente consiste a etudier de maniere detaillee les algorithmes de commande d'un filtre actif de puissance de type shunt realise a partir d'un onduleur de tension connecte sur un reseau triphase de puissance finie. Ces algorithmes ont ete testes en simulation a l'aide du logiciel a usage general electro-magnetic transients program (emtp). A ce propos, cinq methodes distantes pour obtenir les courants de reference pour chaque phase de l'onduleur de tension ont ete formalises. De la meme maniere, la regulation de tension aux bornes du condensateur de cet onduleur a egalement ete abordee. Dans certains cas de figure la numerisation controle-commande a ete developpe de maniere a simuler des structures les plus proches possibles de la realite. Quelques resultats experimentaux obtenus a l'aide d'un filtre actif de commande numerique permettent de valider notre methodologie
13
Silva, Paulo Vitor. "Implementa??o experimental de filtro ativo paralelo de pot?ncia com aplica??o a gerador de indu??o trif?sico." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15322.
Full textAbstract:
Made available in DSpace on 2014-12-17T14:55:44Z (GMT). No. of bitstreams: 1
PauloVS_DISSERT.pdf: 1338370 bytes, checksum: 7f4728ef2faffa30200a5b0daf963f20 (MD5)
Previous issue date: 2010-06-28Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This work describes the experimental implementation of a shunt active power filter applied to a three-phase induction generator. The control strategy of active filter turned to the excitation control of the machine and to decrease the harmonics in the generator output current. Involved the implementation of a digital PWM switching, and was made a comparison of two techniques for obtaining the reference currents. The first technique is based on the synchronous dq reference method and the second on the theory of instantaneous power. The comparison is performed via simulation and experimental results. To obtain the experimental results, was mounted a bench trial and the control and communications needed were implemented using DSP - MS320F2812. The simulation results and experimental data proved the efficiency of the filter to apply, highlighting the technique of instantaneous power
Este trabalho descreve a implementa??o experimental de um filtro ativo paralelo de pot?ncia aplicado a um gerador de indu??o trif?sico. A estrat?gia de controle do filtro ativo voltou-se para o controle de excita??o da m?quina e para a minimiza??o dos harm?nicos na corrente de sa?da do gerador. Envolveu a implementa??o de um chaveamento PWM digital, tendo sido realizada a compara??o de duas t?cnicas para obten??o das correntes de refer?ncia. A primeira t?cnica se baseia no m?todo referencial s?ncrono dq e a segunda na teoria das pot?ncias instant?neas. A compara??o ? realizada via simula??o e resultados experimentais. Para obten??o dos resultados experimentais, foi montada uma bancada experimental e o controle e comunica??es necess?rias foram implementados utilizando-se um DSP - TMS320F2812. Os resultados de simula??o e experimentais obtidos comprovaram a efici?ncia do filtro para a aplica??o, com destaque para a t?cnica das pot?ncias instant?neas
14
Lenwari, Wanchak. "High performance current control for shunt active filters using resonant compensators." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439850.
Full text
15
Yunus, Haroon Iqbal. "Single phase active power filters." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/13282.
Full text
16
Koozehkanani, Ziaddin Daie. "Active filters : a unified approach." Thesis, Brunel University, 1996. http://bura.brunel.ac.uk/handle/2438/5196.
Full textAbstract:
The increase in the occurrence of non-linear loads in power systems has caused considerable concern to power utilities and manufacturers of power electronics equipment. To alleviate the problems caused by generation of current harmonics, there has been considerable interest in the use of active filters. This thesis presents a unified approach to the design of active filter configurations. It is shown that this approach offers a systematic method of classifying existing structures and it can be used for developing new circuits.
17
Odavic, Milijana. "Predictive control for multilevel active power filters." Thesis, University of Nottingham, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765261.
Full text
18
Phinney, Joshua W. (Joshua William) 1973. "Filters with active tuning for power applications." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86779.
Full text
19
Watson, Robert V. "Mains power quality improvement using active filters." Thesis, University of South Wales, 2009. https://pure.southwales.ac.uk/en/studentthesis/mains-power-quality-improvement-using-active-filters(e798030f-aca0-49c1-b85f-c9cb856109bb).html.
Full text
20
Li, Ruomei. "Modelling of active filters for improving power quality." Thesis, University of Bath, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323585.
Full text
21
Marks, John Hywel. "Predictive control of active power filters using neural networks." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396419.
Full text
22
Zhu, Mingjuan 1975. "Design of feedforward active ripple filters for power converters." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9491.
Full textAbstract:
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 76-77).
An active ripple filter is an electronic circuit which cancels or suppresses the ripple current and EMI generated by the power stage of a power converter, thus reducing the passive filtration requirements. This thesis presents the design and evaluation of various current sensing and injection methods for feedforward active filter applications including a Rogowski-Coil sensor, a transformer sensor, a class A injector, and a current transformer based injector. The advantages, tradeoffs, and limitation of each approach are discussed in detail. This thesis also presents the design and evaluation of a prototype feedforword active filter which employs a Rogowski-Coil current sensor and a class A current injector on a 42V /14 V de/de power converter system. Quantitative comparisons between a hybrid passive/active filter and a purely passive filter having the same performance are presented. It is demonstrated that substantial improvements in filter mass and converter transient performance can be achieved using the proposed active ripple filtering method.
by Mingjuan Zhu.
M.Eng.
23
Uz, Eda. "Design And Implementation Of Thyristor Switched Shunt Capacitors." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611616/index.pdf.
Full textAbstract:
This research work deals with the analysis, design and implementation of thyristor switched plain capacitor banks and thyristor switched shunt filter banks. Performances of various thyristor switched capacitor (TSC) topologies are also investigated by simulations. The theoretical findings have been verified by carrying out experimental work on two prototypes implemented within the scope of this research work, one is a wye-connected laboratory prototype and the other is a delta-connected application prototype integrated to some of the SVCs existing in Turkish Coal Enterprise s Plants. The advantages of back-to-back connected thyristor switches over conventional electromechanical contactors are also made clear by conducting an intensive experimental work in the laboratory. A good correlation have been obtained between theoretical and experimental results.
24
LaWhite, Leif E. (Leif Eric). "Active filters for 1 MHz power circuits under strict ripple limitations." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/35336.
Full textAbstract:
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Title as it appeared in Massachusetts Institute of Technology Graduate List, February 1987: Active filters for high frequency power circuits under strict ripple limitations.
Bibliography: leaf 85.
by Leif E. LaWhite.
M.S.
25
Sun, Bo. "A FPGA-based power electronics controller for three-phase four-wire hybrid active power filters." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2547180.
Full text
26
Ng, Chong H. "Control of active filters to attenuate harmonic resonance in power distribution networks." Thesis, Northumbria University, 2007. http://nrl.northumbria.ac.uk/1440/.
Full textAbstract:
Harmonic resonance occurs when the network equivalent shunt harmonic capacitive reactance is associated with the network series harmonic inductive reactance. When such resonance occurs, it amplifies harmonic components with frequency close to the resonance point. Solutions used to solve harmonic resonance problems can be divided into two main categories. One is to reduce the content of harmonic components in the network (e.g. by using active or passive harmonic filters, etc.) and the other is to remove the resonance stimulating factor by shifting away the resonance frequency to a non-critical frequency range (e.g. detuning PFC capacitors, redesigning feeder transformers, etc.). Studies show that these techniques are not adequate to solve harmonic resonance problems in power distribution networks which are dynamic by their nature and with complex interconnections. Due to this, solutions in the category one are designed for localised harmonic distortion compensation, while solutions in the category two lack real-time operation feature. Therefore, it was identified that there is a need for real-time harmonic resonance attenuation that is suitable for power distribution networks. In this thesis, a new real-time Harmonic Resonance Attenuation (HRA) technique is proposed. This technique may be used with ordinary shunt harmonic filters to make them behave like a virtual shunt capacitor or inductor. Thus, looking from the harmonic current source side, the filter alters the network harmonic impedance and hence results in harmonic resonance attenuation. In order to implement the HRA technique, fast measurement of system harmonics in real-time is required. Therefore, in this work, a fast individual harmonic extraction (FIHE) technique is developed to enhance the desired real-time operation of the HRA. The proposed FIHE needs only one sixth of the fundamental cycle to extract any individual harmonic component which is faster than other methods currently available. In addition to the speed, the proposed FIHE provides overshoot free, oscillation free and ripple free extraction characteristics. The proposed HRA and FIHE techniques are described in this thesis with detailed analysis to illustrate their operating principles. A series of simulations and experiments are conducted to evaluate their functionality and performance. Results of the evaluation are presented and discussed in this thesis together with details of the experimental HRA model developed to verify the theoretical and simulation results.
27
Narayanasamy, Balaji. "Impedance Mismatching Based Design of Passive and Active EMI Filters for Power Converters." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461252861.
Full text
28
Song, Byeong-Mun. "Voltage Balancing Techniques for Flying Capacitors Used in Soft-Switching Multilevel Active Power Filters." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/30026.
Full textAbstract:
This dissertation presents voltage stabilization techniques for flying capacitors used in soft-switching multilevel active power filters. The proposed active filter has proved to be a solution for power system harmonics produced by static high power converters. However, voltage unbalance of the clamping capacitors in the active filter in practical applications was observed due to its unequal parameters. Thus, the fundamentals of flying capacitors were characterized dealing with voltage balancing between flying capacitors and dc capacitors under practical operation, rather than ideal conditions.
The study of voltage balancing provides the fundamental high-level solutions to flying capacitor based multilevel converter and inverter applications without additional passive balancing circuits. The use of proposed voltage balancing techniques made it possible to have a simple structure for solving the problems associated with the conventional bulky passive resistors and capacitor banks. Furthermore, the proposed control algorithms can be implemented with a real time digital signal processor. It can achieve the high performance of the active filter by compensating an adaptive gain to the controller. The effectiveness of the proposed controller was confirmed through various simulations and experiments.
The focus of this study is to identify and develop voltage stabilization techniques for flying capacitors used in a proposed active filter. The voltage unbalance is investigated and characterized to provide safe operations. After having defined the problems associated with the voltage unbalance, the most important voltage stabilization techniques are proposed to solve this problem, in conjunction with an instantaneous reactive power (IRP) control of an active filter.
In order to reduce the switching losses and improve the efficiency of the active filter, the proposed soft-switching techniques were evaluated through simulation and experimentation. Experimental results indicate that the proposed active filter achieved zero-voltage conditions in all of the main switches and zero-current turn-off conditions to the auxiliary switches during commutation processes. Also, various studies on soft-switching techniques, multilevel inverters, control issues and dynamics of the proposed active filter are discussed and analyzed in depth.Ph. D.
29
Todeschini, Grazia. "Wind Energy Conversion Systems based on DFIG Technology used as Active Filters: Steady-State and Transient Analysis." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-dissertations/97.
Full textAbstract:
This thesis deals with the performance of a Wind Energy Conversion System operating as a power generator and Active Filter simultaneously. As a power generator, the Wind Energy Conversion System converts wind energy into electric energy; as an Active Filter, it sinks the harmonic currents injected by Non-Linear Loads connected at the same feeder. Three control systems are developed to ensure the described operation; a specific study regarding the compensation of the triplen harmonics is carried out; Doubly-Fed Induction Generator derating is defined; and an engineering economic analysis is performed to determine the profitability of the proposed operation. The Wind Energy Conversion System performance as generator and Active Filter has been studied for steady-state analysis, fast transients and low transients. It is concluded that the proposed control systems allow operating the Wind Energy Conversion System as power generator and harmonic compensator both during steady state and transient operation; the described operation causes power loss increase and voltage distortion that determine the choice of the component and require system derating.
30
Lok, Io Keong. "Study of soft-switching techniques on three-level three-phase four-wire active power filters." Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2493512.
Full text
31
Wang, Lei. "Design and implementation of a three-phase three-wire thyristor controlled LC-coupling hybrid active power filter with low dc-link voltage and wide compensation range." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691876.
Full text
32
Lam, Chi Seng. "An adaptive low dc-voltage controlled LC coupling hybrid active power filter in three-phase four-wire power systems." Thesis, University of Macau, 2012. http://umaclib3.umac.mo/record=b2580608.
Full text
33
Al-Bayaty, Hussein Kamal Anwer. "Novel methods of utilization, elimination, and description of the distortion power in electrical circuits." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/10646.
Full textAbstract:
Firstly, this thesis investigates the electrical power harmonics in an attempt to utilize harmonic current and its distortion power in a novel idea to reconvert the distortion power into useful power. This is done, in order to feed different DC or AC loads in single and three-phase power system by using passive or active filters and accordingly, develop a new topology of hybrid active power filter (HAPF). In addition, this circuit can be considered as a power factor corrector (PFC) because it reduces the total harmonic distortion (THD) and improves the power factor (PF). Secondly, this thesis works on a new design of active power factor correction (APFC) circuit presenting two circuits with the same design principle: the first design consists of two active switches without an external complex control circuit, while the second design contains a single active switch with an additional control circuit. The main contribution of this circuit is 98% reduction of the inductor's value used in the newly proposed PFC circuit in comparison with the conventional boost converter which may lead to a huge reduction in size, weight and the cost of the new PFC circuit. Also, the active switches depend on a carefully designed switching pattern that results in an elimination of the third order harmonic from the input source current which decreases the value of total current harmonic distortion (THDI) to (14%) and improves the input PF to (0.99). Consequently, the simplicity of the design without requiring a complex control circuit and without a snubber circuit plus the minimum size of inductor, gives the newly proposed circuit the superiority on other PFC circuits. Thirdly, this research aims to describe the distortion power through submitting two novel power terms called effective active power (Pef ) & reactive power (Qef ) terms with a new power diagram called Right-Angled Power Triangle (RAPT) Diagram. In addition, a novel de nition of total apparent power (St) has been submitted in order to illustrate the physical meaning of (St) in non-sinusoidal systems. The new RAPT Diagram is based on the orthogonality law and depends on geometrical summation to describe the relationship between different aspects (apparent-active-reactive) of power, and different components (total-fundamental distortion), drawing a bridge to connect the time domain with the frequency domain in a two-dimensional diagram.
34
Borisov, Konstantin A. "Multifunctional voltage source converter for shipboard power systems." Diss., Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-06042007-142951.
Full text
35
Terciyanli, Alper. "Design And Implementation Of A Current Source Converter Based Active Power Filter For Medium Voltage Applications." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611767/index.pdf.
Full textAbstract:
This research work is devoted to the design, development and implementation of a Current Source Converter (CSC) based Active Power Filter (APF) for Medium Voltage (MV) applications. A new approach has been proposed to the design of the CSC based APF for reducing the converter kVA rating considerably. This design approach is called the Selective Harmonic Amplification Method (SHAM), and is based on the amplification of some selected harmoniccurrent components of the CSC by the input filter, and the CSC control system, which is specifically designed for this purpose. The proposed SHAM has been implemented on the first industrial CSC based APF for the elimination of 11th and 13th current harmonics of 12-pulse rectifiers fed from Medium Voltage (MV) underground cables in order to comply with IEEE Std. 519-1992. 450 kVA rated APF with only 205 kVA CSC rating has been connected to the MV bus via a coupling transformer of 600kVA, 34.5/1.1 kV. The power stage of the CSC based APF is composed of water-cooled high voltage IGBT and diode modules. Reference currents to be generated by the CSC are obtained by the use of a selective harmonic extraction method, by mploying synchronously rotating reference frames for each selected harmonic component. An Active damping method is also used to suppress the oscillations around the natural frequency of the input filter, excluding the harmonic components to be eliminated by APF. Simulation and field test results have shown that SHAM can successfully be applied to a CSC based APF for reduction of converter kVA rating, thus making it a cost- competitive alternative to voltage source converter based APFs traditionally used in industry applications.
36
Klein-Heßling, Annegret Verfasser], Doncker Rik W. [Akademischer Betreuer] [De, and Volker [Akademischer Betreuer] Pickert. "Active DC-power filters for switched reluctance drives during single-pulse operation / Annegret Klein-Heßling ; Rik Wivina Anna de Doncker, Volker Pickert." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1187346535/34.
Full text
37
Klein-Heßling, Annegret [Verfasser], Doncker Rik W. [Akademischer Betreuer] De, and Volker [Akademischer Betreuer] Pickert. "Active DC-power filters for switched reluctance drives during single-pulse operation / Annegret Klein-Heßling ; Rik Wivina Anna de Doncker, Volker Pickert." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1187346535/34.
Full text
38
Kwak, Sangshin. "Design and analysis of modern three-phase AC/AC power converters for AC drives and utility interface." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2336.
Full textAbstract:
Significant advances in modern ac/ac power converter technologies and demands
of industries have reached beyond standard ac/ac power converters with voltage-source
inverters fed from diode rectifiers. Power electronics converters have been matured to
stages toward compact realization, increased high-power handling capability, and
improving utility interface. Modern ac/ac power converter topologies with various
control strategies have been introduced for the further improvements, such as matrix
converters, current-fed converters, PWM rectifiers, and active power filters. In this
dissertation, several new converter topologies are proposed in conjunction with
developed control schemes based on the modern ac/ac converters which enhance
performance and solve the drawbacks of conventional converters.
In this study, a new fault-tolerant PWM strategy is first proposed for matrix
converters. The added fault-tolerant scheme would strengthen the matrix converter
technology for aerospace and military applications. A modulation strategy is developed
to reshape output currents for continuous operation, against fault occurrence in matrix
converter drives.
This study designs a hybrid, high-performance ac/ac power converter for high
power applications, based on a high-power load commutated inverter and a mediumpower
voltage source inverter. Natural commutation of the load commutated inverter is
actively controlled by the voltage source inverter. In addition, the developed hybrid
system ensures sinusoidal output current/voltage waveforms and fast dynamic response
in high power areas.
A new topology and control scheme for a six-step current source inverter is
proposed. The proposed topology utilizes a small voltage source inverter, to turn off
main thyristor switches, transfer reactive load energy, and limit peak voltages across
loads. The proposed topology maximizes benefits of the constituent converters: highpower
handling capability of large thyristor-based current source inverters as well as fast
and easy control of small voltage source inverters.
This study analyzes, compares, and evaluates two topologies for unity power
factor and multiple ac/ac power conversions. Theoretical analyses and comparisons of
the two topologies, grounded on mathematical approaches, are presented from the
standpoint of converter kVA ratings, dc-link voltage requirements, switch ratings,
semiconductor losses, and reactive component sizes. Analysis, simulation, and
experimental results are detailed for each proposed topology.
39
Malvezzi, Victor Belieiro. "Estudo e projeto de controladores aplicados na malha de controle de corrente de um filtro ativo de potência paralelo." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/1200.
Full textAbstract:
Este trabalho apresenta o estudo, projeto e implementação de quatro estratégias de controle de corrente de compensação para uma topologia monofásica de Filtro Ativo de Potência Paralelo (FAPP), sendo estas denominadas, controlador PI Clássico no eixo de coordenadas ( ), controlador PI Clássico no eixo de coordenadas ( – ), Controlador PI Ressonante no eixo de coordenadas ( ) e Controlador PI Ressonante no eixo de coordenadas ( ). A tensão no barramento CC é controlada por um controlador PI clássico. O FAPP é composto por um inversor full-bridge conectado a rede elétrica, o qual opera de modo a fornecer à rede elétrica uma corrente de compensação, com a mesma amplitude e em fase oposta à corrente harmônica da carga. O algoritmo baseado no sistema de eixos de referência síncrona (algoritmo ) é utilizado para obtenção da corrente de referência de compensação. Análises matemáticas são realizadas de forma a obter o modelo que representa o sistema físico do FAPP. Além disso, é apresentada uma metodologia de projeto para a obtenção dos ganhos dos controladores PI das malhas de corrente e de tensão do barramento CC. É também apresentada à metodologia para sintonia das parcelas ressoantes dos controlador e . Resultados de simulação e experimentais são apresentados de forma a validar o desenvolvimento teórico realizado e comparar o desempenho do FAPP, quando submetido às estratégias de controle propostas.This work presents the study, design and implementation of three control strategies for compensating current in a single-phase Shunt Active Power Filter (SAPF), such as the conventional PI controller based on reference frame ( ), conventional PI controller based on reference frame ( ), PI plus resonant controller based on reference frame ( ) and PI plus resonant controller based on reference frame ( ). The DC bus voltage is controlled by using a linear PI controller. The SAPF consists of a full-bridge inverter connected to the grid. The main function of the shunt SAPF is to provide to the utility grid an adequate compensation current, containing the same amplitude and opposite phase of the load current harmonics. The algorithm used for obtaining the reference compensation current is based on the synchronous reference frame (SRF algorithm). Mathematical analyzes are developed in order to obtain the mathematical model which represents the SAPF physical system. In addition, it is presented a design methodology employed for obtaining the gains of the PI controllers used in both the compensation current and the DC-bus voltage loops. It is also presented methodology for tuning the resonant controllers. Simulation and experimental results are presented to validate the theoretical development and compare the performance of FAPP when submitted to the proposed control strategies.
40
Pigazo, López Alberto. "Método de control de filtros activos de potencia paralelo tolerante a perturbaciones de la tensión de red." Doctoral thesis, Universidad de Cantabria, 2004. http://hdl.handle.net/10803/10632.
Full textAbstract:
La utilización de filtros activos paralelo mejora la eficiencia del suministro eléctrico mediante la modificación de las características de la forma de onda de las corrientes de línea. Trabajos de investigación anteriores destacan la complicada estructura de los controladores empleados en este tipo de soluciones y su sensibilidad a la distorsión de la onda de tensión en el punto donde se realiza su conexión. El objetivo fundamental de esta tesis es el desarrollo de un controlador para filtros activos de potencia tolerante a desequilibrios de tensión, huecos de tensión y armónicos de tensión. Objetivo secundario de este trabajo es el diseño de los algoritmos necesarios para el control de un filtro activo de potencia paralelo polifásico mediante una tarjeta basada en un procesador digital de señal.Shunt active power filters (APF) modify the phase current waveform characteristics, which allow to increase the efficiency of electrical power grids. Previous research works establish the complex structure of controllers applied to APFs and their sensibility to voltage waveform disturbances.The aim of this thesis is the developing of a controller for shunt active power filters with tolerance to voltage unbalances, voltage dips and voltage harmonics. The proposed controller, implemented on a DSP target board, will be tested on a three-phase active power filter.
41
Beaulieu, Steeve. "Étude et mise au point d'un filtre actif d'harmoniques en vue d'améliorer la qualité de l'alimentation électrique /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2007. http://theses.uqac.ca.
Full textAbstract:
Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2007.La p. de t. porte en outre: Mémoire présenté comme exigence partielle de la maîtrise en ingénierie. CaQCU Bibliogr.: f. [121]-124. Document électronique également accessible en format PDF. CaQCU
42
Guerreiro, Joel Filipe 1988. "Design and implementation of a multilevel active power filter for more electric aircraft variable frequency systems = Aplicação de filtros ativos multiníveis em sistemas elétricos de aeronaves em regime de frequência variável." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259303.
Full textAbstract:
Orientador: José Antenor PomilioDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-25T18:11:11Z (GMT). No. of bitstreams: 1 Guerreiro_JoelFilipe_M.pdf: 10178060 bytes, checksum: 342fb378bb2d1fd88084a0360e541d24 (MD5) Previous issue date: 2014
Resumo: Filtros Ativos de Potência Aeronáuticos (FAPA) são geralmente utilizados para melhoria da Qualidade da Energia em Sistemas Elétricos de Potência Aeronáuticos (SEPA). Os FAPA compensam os harmônicos de corrente, aumentam o fator de potência e minimizam os efeitos de cargas desbalanceadas. Este trabalho apresenta o desenvolvimento, simulação e implementação de um FAPA pra um SEPA avançado de velocidade e frequência variável. O SEPA é muito diferente dos sistemas elétricos residenciais e industriais, nesses sistemas a frequência pode variar de 360 Hz a 800 Hz, além do mais a carga se reconfigura repetidamente. Deste modo, uma estratégia avançada de filtragem ativa é necessária para SEPAs, O FAPA proposto neste trabalho é composto por um inversor multinível do tipo cascata assimétrica, o algoritmo de controle é implementado utilizando a teoria da potência conservativa e a sincronia do FAPA com o SIPA é realizada por meio de um algoritmo PLL com filtro de Kalman. Um protótipo trifásico é implementado para validar ambos o FAPA e as simulações
Abstract: Aircraft Active Power Filters (AAPFs) are most commonly used to improve energy quality in Aircraft Electrical Power Systems (AEPS by means of mitigating current harmonics, improving the source power factor and minimizing the effects of unbalanced loads. This work presents the design, simulation and implementation of a Multilevel AAPF for a Variable Speed Variable Frequency (VSVF) advanced aircraft electric power system. The AEPS is very different than the residential and industrial power systems, in these systems, the frequency may vary between 360 Hz and 800 Hz, and the load dynamics is often modified. For aircraft purposes an enhanced filtering technique is required. The proposed AAPF topology is composed by an Asymmetrical Multilevel Inverter (AMI), controlled by the Conservative Power Theory (CPT) and synchronized by a Kalman Filter Phase-Locked Loop (KF-PLL). A three phase AAPF prototype was implemented in order to investigate the proper system operation and accurateness to the simulations
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
43
Furtado, Pablo Carlos de Siqueira. "Controle de um filtro ativo de potência bifásico a três fios utilizando a teoria p-q monofásica." Universidade Federal de Juiz de Fora (UFJF), 2014. https://repositorio.ufjf.br/jspui/handle/ufjf/4163.
Full textAbstract:
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-24T20:26:56Z
No. of bitstreams: 1
pablocarlosdesiqueirafurtado.pdf: 4055605 bytes, checksum: b23cd5bfadf3eb9e69e3e5e804322231 (MD5)Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-25T15:21:49Z (GMT) No. of bitstreams: 1 pablocarlosdesiqueirafurtado.pdf: 4055605 bytes, checksum: b23cd5bfadf3eb9e69e3e5e804322231 (MD5)
Made available in DSpace on 2017-04-25T15:21:49Z (GMT). No. of bitstreams: 1 pablocarlosdesiqueirafurtado.pdf: 4055605 bytes, checksum: b23cd5bfadf3eb9e69e3e5e804322231 (MD5) Previous issue date: 2014-06-27
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Esta dissertação apresenta uma estratégia para controlar um filtro ativo de potência (FAP) paralelo bifásico a três fios. A aplicação desse FAP pode ser implementada como uma funcionalidade extra do conversor fonte de tensão do sistema de propulsão de veículos elétricos (VE), o que seria útil para compensar instalações elétricas residenciais e comerciais com fornecimento de energia bifásico a três fios. Apresenta-se o princípio de funcionamento do FAP bifásico e é tratada sua modelagem matemática. É feita uma revisão dos conceitos de potências instantâneas p e q em sistemas monofásicos, a chamada teoria p–q monofásica. É mostrada ainda a interpretação dessas grandezas e sua relação com as potências ativa e reativa convencionais. Em seguida, são feitas adaptações na implementação dessa teoria. A principal adaptação está na forma de implementar as transformações αβ monofásicas. Com essas adaptações, a teoria p–q modificada é utilizada para descrever o algoritmo de controle desenvolvido para o FAP bifásico. A estratégia de compensação adotada consiste na compensação de todas as componentes harmônicas de corrente, da potência reativa e na equalização das correntes nas fases envolvidas. São apresentados resultados obtidos em estudos de simulação da operação do FAP bifásico em regime permanente e sob transitórios das cargas. O trabalho mostra ainda alguns resultados experimentais do FAP em operação. Conclui-se que os resultados obtidos validam o princípio de operação do FAP bifásico e a estratégia de controle proposta.
This thesis presents an strategy to control a two–phase, three-wire shunt active power filter (APF). This APF can be implemented as an extra functionality of the embedded voltage source converter in the propulsion system of an electric vehicle (EV). This application would be useful in the compensation of residential and commercial electrical installations fed by a two–phase three–wire grid connection. The working principle of shunt two-phase APF is presented and its mathematical models are also treated. Concepts of the instantaneous powers p and q, called single-phase p–q theory, are reviewed. The relationship between these quantities and the conventional active and reactive powers is discussed. Then, some adaptations are done in the implementation of such theory. The main one is related to the implementation method of singlephase αβ transformations. After these adaptations, the modified p–q theory is used to described the developed algorithm to control the two–phase APF. The adopted control strategy consists of compensating all current harmonics and reactive power, as well as equalizing currents in involved phases. Simulation results are presented to show the APF operation in steady-state and under load changes. Yet, some experimental results are presented to show the APF in operation. The obtained results validate the presented working principle and the control strategy proposed in this thesis.
44
Oliveira, Caio Gomes de. "Estudo sobre conservação de energia eletrica e qualidade de energia eletrica." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259103.
Full textAbstract:
Orientadores: Fujio Sato, Ernesto Ruppert FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-14T19:28:59Z (GMT). No. of bitstreams: 1 Oliveira_CaioGomesde_M.pdf: 16585052 bytes, checksum: 61d70f191de8c032a8ab39cdcf8c652c (MD5) Previous issue date: 2009
Resumo: Este trabalho trata de dois temas de grande relevância, principalmente nos últimos anos, na área de energia elétrica: a conservação e a qualidade da energia elétrica. Os estudos são baseados em dados de grandezas elétricas coletados por equipamentos de monitoração e gerenciamento de energia instalados em pontos distintos do Campus da Universidade Estadual de Campinas. A conservação de energia elétrica relaciona-se ao seu uso mais eficiente e sem desperdícios, importante por proporcionar um aumento da energia disponível, sem que sejam necessários grandes investimentos em geração, transmissão e distribuição, reduzindo, assim, impactos ambientais. A avaliação deste quesito surge de um projeto piloto, o Projeto Ecogera, cuja finalidade é avaliar a eficiência energética, por meio de um programa de uso racional e da exploração de fontes alternativas de energia elétrica. Aqui é discutido, então, o módulo de conservação de energia, desenvolvido em unidades de consumo com características típicas em relação ao tipo de atividade exercida na universidade, focando na redução de consumo em iluminação. Uma boa qualidade de energia elétrica remete à ausência de variações anormais na tensão, relacionada à continuidade do fornecimento e à forma de onda senoidal da alimentação. Os problemas na qualidade de energia têm se agravado ao longo dos anos, principalmente devido ao aumento das cargas não lineares, à maior sensibilidade dos equipamentos e à grande interconexão da rede elétrica, e podem resultar em má operação ou prejuízo a dispositivos. É dado um maior enfoque nas perturbações na amplitude da tensão e nas distorções na forma de onda, mostrando suas principais causas e meios de contorná-las. No primeiro caso, são registrados transitórios, interrupções, afundamentos e elevações de tensão, feitas as devidas análises, e avaliadas suas influências em equipamentos por meio da Curva ITI (CBEMA), a qual possibilita a determinação de possíveis danos ou falhas nos mesmos. No segundo caso, nos diversos pontos de medição é avaliada a presença de harmônicas, tanto pela análise das formas de onda e de seus conteúdos espectrais como pela taxa de distorção harmônica num período de uma semana. Por fim, são estudadas teorias de potências elétricas trifásicas, em especial a Teoria pq de Potências Instantâneas, importante na aplicação de filtros ativos, cuja função é atenuar as correntes harmônicas geradas por cargas não lineares. Os dados reais medidos das tensões e correntes instantâneas foram submetidos a um programa computacional desenvolvido a partir do modelo matemático de um filtro ativo com compensação paralela e método de compensação baseado na Teoria pq Modificada de Potências Instantâneas, obtendo-se como resposta o desempenho do filtro na eliminação das harmônicas nas correntes vistas pela fonte de alimentação.
Abstract: This work deals with two issues of large relevance, especially in recent years about electric power: energy economy and power quality. The studies are based on data collected by various measurement and energy management instruments at different points in the Campinas State University Campus (Unicamp), in São Paulo State, Brazil. The performance of energy relates to its more efficiently use and without wasting, which is important to increase the amount of available energy, without large investments in generation, transmission and distribution, thereby reducing environmental impacts. A Project has been developed, named Ecogera, whose purpose is to evaluate the energy efficiency, through a program of rational use and development of alternative sources of energy. The module of energy economy is discussed here, developed in units of consumption with typical characteristics for the type of work performed at the university, focusing on the reduction of lighting consumption. A good power quality refers to the absence of abnormal variations in voltage, related to continuity of supply and the sinusoidal waveform of the power supply. The power quality problems have been increased over the years, mainly due to the increase of nonlinear loads, the increased sensitivity of the equipment and the large interconnection of the power networks, and can result in misoperation or damage of the devices. A greater focus is given on the voltage amplitude disturbances and the distortion in the waveform, showing its main causes and means of overcoming them. In the first case transients, interruptions, sags and swells are recorded, adequate analysis are done, and their influence on the equipment are evaluated by the ITI Curve (CBEMA), which enables the determination of possible damage or failures in them. In the second case, the presence of harmonics is evaluated in the various points of measurement, either by the analysis of waveforms and its spectral content or by the total harmonic distortion over a one-week period. Finally, tree-phase electrical power theories are studied, especially the Instantaneous pq Power Theory, which is important in the application of active filters, whose function is to reduce the harmonic currents generated by nonlinear loads. The real measured data of the instantaneous voltages and currents was put in a computacional program developed from the mathematical model of an active filter with parallel compensation and using a compensation method based on the Power Instantaneous Modified pq Theory and its influence seem by the current supply is obtained by the harmonic eliminations.
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
45
Zimmermann, Cristiano Porporatti. "Controladores repetitivos aplicados a filtros ativos de potência sob variações de carga e de frequência da rede." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/1749.
Full textAbstract:
Este trabalho apresenta o desenvolvimento e adaptação de técnicas para minimizar os efeitos das variações de carga e de frequência da rede em controladores repetitivos aplicados a filtros ativos de potencia. Para minimizar os efeitos provenientes de sinais aperiódicos decorrentes da conexão ou desconexão de cargas não lineares é elaborada uma técnica que diferencia cargas lineares de não lineares. Esta técnica opera de forma a só reinicializar o controlador quando o erro devido ao transitório for de valor considerável ou quando ocorrer a transição de carga não linear para linear. Também é desenvolvido um algoritmo de adaptação do ganho do controlador repetitivo baseado em uma função de adaptação sigmóide, com intuito de minimizar os efeitos provocados por ruído aleatório no sistema de medição. Na sequência, são analisados os efeitos da variação de frequência e apresentados os principais métodos de compensação deste problema. Entre as soluções apresentadas, encontra-se o método da alteração do número de amostras por período e o método da variação da taxa de amostragem. O primeiro possui a vantagem de utilizar técnicas de projeto lineares e invariantes no tempo. Já o segundo método, por variar a frequência de amostragem, deve ser analisado sob um aspecto de sistema variante no tempo, o que acarreta em maior complexidade na prova de estabilidade. Os algoritmos de reinicialização e adaptação do ganho do controlador repetitivo são analisados sob variação da frequência da rede. Para a compensação da variação da rede, utiliza-se o método do truncamento do número de amostras e o da variação da taxa de amostragem. Por fim, para validar os algoritmos desenvolvidos s˜ao realizados testes em uma plataforma experimental.This work presents the development and modification of techniques to reduce the effects of load variation and mains frequency deviation in repetitive controllers applied to active power filters. To minimize the effects of aperiodic signals resulting from the connection or disconnection of non-linear loads is developed a technique which recognizes linear and nonlinear loads, and operates to reset the controller only when the error due to the transition of considerable value, and the transition is from non-linear to linear load. An algorithm to adapt the gain of the repetitive controller, based on a sigmoid function adaptation, in order to minimize the effects caused by random noise in the measurement system is also used. This work also analyzes the effects of frequency variation and presents the main methods to cope with this situation. Some solutions are the change in the number of samples per period and the variation of the sampling rate. The first has the advantage of using linear design techniques and results in a time invariant system. The second method changes the sampling frequency and leads to a time variant system that demands a difficult analysis of stability. The proposed algorithms were tested using the methods of truncation of the number of samples and the method of changing the sampling rate of the system to compensate possible frequency variations of the grid. Experimental results are presented to validate the proposal.
46
Kuo, Hung-hsi, and 郭鴻熹. "Analysis and Control of Three-Phase Shunt Active Power Filters." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/06298344311625324905.
Full textAbstract:
博士國立臺灣科技大學
電機工程系
89
This dissertation presents the design and implementation of three-phase shunt active power filters. The principle of operation of active power filters is to generate compensating current into the power system for cancelling the current harmonics generated by nonlinear loads and correcting power factor of input source. The determination for compensating currents is conducted by firstly sensing the currents from the nonlinear loads. The direct and quadrature components of the compensating currents are then obtained from the corresponding load current components in the rotating frame by mean of a digital low-pass filter. Using the proposed determination method needs no calculation for the instantaneous real and reactive powers on the load side. This will thus results in pronounced reduction of calculation procedure and sensor component cost. A novel and simple analytic model is proposed to a three-phase active power filter system for design and implementation of the active power filter controller. The voltage decouplers and pole-zero cancellation are used in the current regulators to simplify the current control plant to a first-order delay type. This simplification is conducted by considering the delay times caused by the low-pass filter of reference current calculation circuits, line inductors of active power filter and feedback circuit of dc-link voltage. From the derived analytic model, the cut-off frequency of low-pass filter and controller parameters can be appropriately determined to increase the harmonic current compensating capability of active power filter and improve the dynamic response of dc-link voltage. In addition, the active power filter of centralized, non-common dc-link voltage topology designed with small-rated power modules are adopted to the proposed paralleled active power filter system. The compensating capacity and utilization rate of the parallel system can be flexibly increased by mean of suitable switch in and off control. A current distribution controller is used to determine the required number of parallel module and calculate the compensating current commands for each module. The compensating weighting factor for each module can be computed according to the current sharing control strategy. Applying the proposed control approach, the parallel operation system has the advantages of easy maintenance, good expandability as well as higher reliability and efficiency. The performance of the proposed system is first simulated by digital computer. A personal-computer based digital control is used to implement the system. A 2.5 kVA single module and two 2.5 kVA module parallel operation prototype are then built to evaluate the performance of the single active power filter and the parallel operation system, respectively. The proposed system performances have been shown to possess fast current harmonic compensation, low input current harmonics, near unity input power factor and low dc-link fluctuation voltage with balanced and unbalanced nonlinear loads.
47
Huang, Jhong-Wei, and 黃仲維. "A Shunt Active Power Filter for Harmonic Isolation." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/47754233242281222953.
Full text
48
Shiu, Jeng-Jang, and 許政章. "Implementation and Verification of High Power Shunt Active Power Filter." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/qjg6bf.
Full text
49
Li, Chien-Hsing, and 李建興. "A Shunt Active Power Filter Adopting Lyapunov Control Approach." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/97226794328213955465.
Full textAbstract:
博士雲林科技大學
工程科技研究所博士班
98
In this dissertation, a Lyapunov-based current control method is proposed for a single-phase shunt active power filter (APF) to reduce source current harmonics and reactive power. Most studies only show control block diagrams with classic control methods. These control schemes look very attractive for their simplicity and ease of implementation, but lack in presenting an adequate compensation algorithm or stability analysis of active power filters. The control law is derived from directly applying the Lyapunov stability theory to the integral controller, so that the closed-loop systems possess better harmonic current elimination. The proposed APF controller forces the supply current to be sinusoidal, with low current harmonics, and to be in phase with the line voltage. An experimental model of the active power filter has a power rating of 1 kW. The switching frequency of the active power filter is 20 kHz which can be produced by the electronic devices. The power factor is improved from 0.63 to 0.97 and the THD is reduced from 56% to 3.74% with a phase-angle controlled load. Computer simulations and experimental results obtained from a laboratory system developed in this dissertation verify the viability and effectiveness of the full-digital-controlled active filter. The features of the proposed system include: 1) the performance of the APF is much improved when adopting the Lyapunov stability approach. It is easy to select a suitable control gain to achieve stability compensation while maintaining the system stability. 2) Better harmonic compensation performance is obtained because the Lyapunov-based theory is used in the control algorithm, which is very important for active power filters to be used in practical applications.
50
Shee, T. C., and 施泰彰. "A Study on Reference Compensation Current Strategies for Three-Phase Four-Wire Shunt Active Power Filters." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/58215613068166539976.
Full textAbstract:
碩士國立中正大學
電機工程研究所
90
This thesis proposes a new reference compensation current strategy of shunt active power filters used in a three-phase, three-wire or four-wire distribution system with unbalanced, ideal or non-ideal source voltages supplying balanced or unbalanced nonlinear loads. Firstly, a comparative study of the effectiveness for six conventional approaches for determining reference compensation currents of shunt active power filters is present. Then, a novel reference compensation currents approach is described. The proposed compensation strategy makes implementation of the compensator of the active power filter simpler than those conventional approaches. Moreover, the proposed compensation strategy is verified with an virtual implementation of controller with using MATLAB/Simulink. It is shown that even the source is non-ideal, when supplying a nonlinear load, the source current is maintained sinusoidal and in phase with the positive-sequence source voltage. Therefore, the active power filter effectively controls the source power factor and harmonic currents generated by the nonlinear load. In addition, it does not require any active elements in the implementation of the active power filter.