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Latifi, Hojjat. "Enhanced performance bidirectional quasi-Z-source inverter controller." Thesis, University of East London, 2015. http://roar.uel.ac.uk/4669/.
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A novel direct control of high performance bidirectional quasi-Z-source inverter (HPB-QZSI), with optimized controllable shoot-through insertion, to improve the voltage gain, efficiency and to reduce total harmonic distortion is investigated. The main drawback of the conventional control techniques for direct current to alternating current (DC-AC) conversion is drawn from the multistage energy conversion structure, which implies complicated control, protection algorithms and reduced reliability due to the increased number of switching devices. Theoretically, the original Z-source, Quasi-Z-source, and embedded Z-source all have unlimited voltage gain. Practically, however, a high voltage gain (>2 or 3), will result in a high voltage stress imposed on the switches. Every additional shoot-through state increases the commutation time of the semiconductor switches, thereby increasing the switching losses in the system. Hence, minimization of the commutation time by optimal placing of the shoot-through state in the switching time period is necessary to reduce the switching loss. To overcome this problem, a combination of high performance bidirectional quasi-Z-source inverter with a sawtooth carrier based sinusoidal pulse width modulation (SPWM) in simple operation condition for maximum boost control with 3rd harmonic injection is proposed. This is achieved by voltage-fed quasi-Z-source inverter with continuous input current, implemented at the converter input side which can boost the input voltage by utilizing the extra switching state with the help of shoot-through state insertion technique. This thesis presents novel control concepts for such a structure, focusing mainly on the control of a shoot-through insertion. The work considers the derivation and application of direct controllers for this application and scrutinizes the technical advantages and potential application issues of these methodologies. Based on the circuit analysis, a small signal model of the HPB-QZSI is derived, which indicates that the circuit is prone to oscillate when there is disturbance on the direct current (DC) input voltage. Therefore, a closed-loop control of shoot-through duty cycle is designed to obtain the desired DC bus voltage. The DC-link boost control and alternating current (AC) side output control are presented to reduce the impacts of disturbances on loads. The proposed strategy gives a significantly high voltage gain compared to the conventional pulse width modulation (PWM) techniques, since all the zero states are converted into shoot-through states. The simulated results verify the validity and superiority of the proposed control strategies.
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Al-Egli, Fares, and Moumin Hassan Mohamed. "Control, Design, and Implementation of Quasi Z-source Cascaded H-Bridge Inverter." Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-152711.
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This report is about control, design and implementation of a low voltage-fed quasi Z-source three-level inverter. The topology has been interesting for photovoltaic-systems due to its ability to boost the incoming voltage without needing an extra switching control. The topology was first simulated in Simulink and later implemented on a full-bridge module to measure the harmonic distortion and estimating the power losses of the inverter. An appropriate control scheme was used to set up a shootthrough and design a three-level inverter. The conclusion for the report is that the quasi Z-source inverter could boost the DC-link voltage in the simulation. But there should be more consideration to the internal resistance of the components for the implementation stage as it gave out a lower output voltage than expected.
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Gorgani, Aida Gorgani. "Quasi Z-Source-Based Multilevel Inverter For Single Phase Photo Voltaic Applications." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1471615403.
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Malengret, Jean-Claude. "A 3-phase Z-source inverter driven by a novel hybrid switching algorithm." Master's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/14698.
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A 3-phase Z-source inverter has been researched, designed, simulated, builtand tested. The purpose of the inverter is to deliver 3-phase 400 VAC from aDC supply that can vary over a range of 20 to 70 Vdc. This is done with a Zsourceinverter topology which is a single conversion method with no additionalDC to DC boost converter. A novel DSP control algorithm allows the inverter toachieve the following:· Run Space Vector Pulse Width Modulation (SV-PWM) for maximum DCbus voltage utilization while boosting the DC bus during zero space vectorstates using shoot through.· Seamless transition between modulation control and modulation / shootthrough control.· Optimised efficiency and DC bus utilisation using Hybrid Space VectorBoost Pulse Width Modulation (HSVB PWM) which is unique to thisdissertation.Such a system is particularly suited to fuel cell and particularly wind turbineapplications where the DC bus voltage is varies over a wide range resulting inthe need for a DC to DC buck/boost to regulate the DC bus to maintain a steady3-phase sinusoidal output. A further application could be for general purpose 3-phase inverter capable of operating on different DC standard bus voltages ( e.g.24, 36, 48 VDC).The benefits of a Z-source topology for the above purposes are a reduction inhigh power semi-conductor components (e.g. power MOSFET). There is also areduction in switching losses and inherent shoot through protection.Furthermore, the inverter is more robust in the sense that it is not vulnerable to spurious shoot through, which could be disastrous in the case of a traditionalvoltage fed inverter.
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Rotondi, Andrea. "Studio e simulazione di un inverter di tipo Z per veicoli elettrici." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4294/.
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Studio e simulazione di un inverter di tipo Z in grado di innalzare il valore della tensione fornita dalla sorgente fino alla tensione richiesta al carico. L'inverter Z-source può essere utilizzato convenientemente nell'azionamento di un veicolo elettrico, in particolare ad idrogeno.
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Kitson, Joanne. "Shunt regulation of a three-phase voltage bus by means of a bi-directional voltage-fed quasi Z-source inverter." Thesis, University of Bristol, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.761205.
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Kottra, Marton. "2-Level Impedanz-Zwischenkreisinverter für einen Fahrmotor in elektrisch angetriebenen Fahrzeugen." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-189926.
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Wechselrichter im Antriebsstrang von Elektrofahrzeugen verbinden Batterie und Motor miteinander. Bei konventionellen Wechselrichtern ist die Ständerspannung des Fahrmotors durch die Batteriespannung begrenzt. Dies ist vor allem bei hohen Drehzahlen nachteilig, da hier ein zusätzlicher feldschwächender Strom notwendig ist. Dieser Strom wiederum verursacht zusätzliche Verluste in der Maschine und der Leistungselektronik. Einen alternativen Ansatz bieten hochsetzende Wechselrichter. Die Begrenzung der Ständerspannung durch die Batterie entfällt. In der vorliegenden Diplomarbeit werden zwei hochsetzende Wechselrichter miteinander verglichen. Zunächst wird die Funktionsweise des Wechselrichters mit Hochsetzsteller und des ZSource-Wechselrichters erläutert. Danach werden Bauelemente für beide hochsetzende Wechselrichter ausgewählt. Anschließend werden die Verluste und das thermische Verhalten der ausgewählten Konfigurationen analysiert und mit Matlab simuliert. Abschließend werden der Wechselrichter mit Hochsetzsteller und der Z-Source-Wechselrichter bezüglich der Kriterien Wirkungsgrad, Zuverlässigkeit und Fertigungsaufwand miteinander verglichenInverter in the drive train of electric vehicles connect the battery to the machine. Using conventional inverters, the stator voltage is limited by the battery voltage. This is mainly a disadvantage at a high speed, since an additional field weakening current is needed. This current produces extra losses in the electrical machine and the power electronics. DC/DC boosted inverters offer an alternative solution. A limitation of stator voltage through the battery does not occur. This diploma thesis is comparing two kinds of DC/DC boosted inverters. First the functionality of an inverter with boost converter and that of a Z-Sourceinverter are presented. Afterwards the electrical components for both inverters are chosen and are simulated using Matlab. Finally the results of the simulation are compared with respect to power effciency, reliability of the electrical components and the effort of production
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Jung, Jin Woo. "Modeling and control of fuel cell based distributed generation systems." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1116451881.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvi, 209 p.; also includes graphics. Includes bibliographical references (p. 202-209). Available online via OhioLINK's ETD Center
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Quinalia, Mateus Siqueira. "Modelagem, análise de estabilidade e controle da tensão da malha Z em inversores fonte de impedância." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-04022019-091341/.
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O uso crescente de fontes alternativas de energia exige conversores de energia capazes de aumentar sua tensão nos terminais e conectá-los ao sistema de distribuição. Neste contexto, o conversor step-up clássico (conversor de potência CC/CC) e o inversor de fonte de tensão (VSI) são as soluções mais aplicadas para processar o fluxo de energia da fonte para a rede. No entanto, apresentam um baixo rendimento devido ao duplo estágio de conversão, isto é, a energia flui também através dos conversores de energia CC/CC e CC/CA. Para evitar esse tipo de desvantagem, no início da última década, o Z-Source-Inverter (ZSI) foi introduzido. Nesta nova solução, o conversor de energia CC/CC responsável por elevar a tensão nos terminais do conversor foi removido e uma rede de impedância LCLC foi adicionada com duas tarefas, ou seja, aumentar a tensão do terminal e melhorar a eficiência do ZSI. Infelizmente, os trabalhos da literatura não apresentaram um modelo matemático generalizado para apoiar os projetistas de conversores de potência na análise de estabilidade, projeto de controladores ou avaliar o ganho de tensão do conversor. Neste sentido, esta dissertação propõe o desenvolvimento de um modelo matemático completo e a análise de estabilidade da planta. Para suportar todo o desenvolvimento teórico, foi realizado um conjunto de análises no domínio do tempo e da frequência. Por fim, verificou-se o controle da tensão do elo CC para suportar todas as afirmações apresentadas neste trabalho (controle da tensão no capacitor da rede Z).The growing use of alternative energy sources require power converters able to boost their terminal voltage and connect them to the distribution system. In this context, the classical step-up converter (DC/DC power converter) and the voltage source inverter (VSI) are the most applied solutions to process the power flow from the source to the grid. However, they present a low efficient because of the double stage of conversion, i.e. the power flows through the DC/DC and DC/AC power converters as well. To avoid this type of drawback, in the beginning of the last decade the impedance source inverter (ZSI) was introduce. In this new solution, the DC/DC power converter responsible for boosting the voltage at the DC-source terminals was removed and a Z (LCLC-network) was added with two tasks, i.e. boost the DC-source terminal voltage and improve the ZSI efficiency. Unfortunately, the papers in the literature did not present a generalized mathematical model to support designers of power converters in the analysis of stability, design of controllers or evaluate the voltage gain of the converter. In this sense, this thesis proposes the development of a complete mathematical model and the stability analysis of the plant. To support all the theoretical development a set of analysis in the time and frequency-domain was performed. Finally, the control of DC-link voltage was verified to support all the statements presented in this thesis (control on the Z-network voltage capacitance).
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TENÓRIO, JÚNIOR Gilberto Alves. "Inversores Fonte Z monofásicos e conversor de dois estágios para sistemas fotovoltaicos sem Transformador." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/19498.
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Dissertação Mestrado M276 - Gilberto.pdf: 3559945 bytes, checksum: e0e92cec09c72c5a7b8b98260c3b9a8e (MD5)Made available in DSpace on 2017-07-11T12:39:13Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação Mestrado M276 - Gilberto.pdf: 3559945 bytes, checksum: e0e92cec09c72c5a7b8b98260c3b9a8e (MD5) Previous issue date: 2016-03-22
Este trabalho apresenta um estudo comparativo de conversores monofásicos aplicados a sistemas fotovoltaicos sem transformador. Topologias de inversores sem transformador têm menores custos, tamanho e peso. Contudo, a não utilização do transformador pode ser responsável por consideráveis valores de correntes de fuga. A associação em série de vários módulos fotovoltaicos se faz necessária para alcançar o nível de tensão desejado no barramento c.c.. Com o intuito de reduzir o número de módulos fotovoltaicos em série, topologias com característica de elevação de tensão (boost) podem ser utilizadas. Portanto, topologias que possuem estas características e que possam apresentar baixos valores de correntes de fuga devem ser escolhidas para o estudo. As topologias presentes neste trabalho são: o conversor de dois estágios, o inversor fonte Z monofásico com diodo adicional, e o inversor fonte Z de três estados.
This work presents a comparative study of single-phase converters applied to transformerless photovoltaic systems. Topologies of transformerless inverters have lower costs, size and weight. However, not using it may cause considerable amounts of leakage currents. The association in series of several PV modules is needed to achieve the voltage level desired in d.c. bus. In order to reduce the number of photovoltaic modules in series, topologies with voltage boost characteristic can be used. Therefore, topologies that have voltage boost characteristic and can have low leakage current values are chosen for the study. Topologies present in this work are: the two stages single-phase converter, the single-phase Z-source inverter with additional diode, and the single-phase three switch three state Z-source inverter.
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Huang, Jing-Zhe, and 黃靖哲. "The Study of Z-source Inverter for Power Conversion." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/73777391328830631863.
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碩士國立交通大學
機械工程學系
100
Wind energy, Fuel cell, or Solar power system are potential renewable energies. The power conversion systems are often AC-DC-AC system connected to the grid. But DC-link voltage behind the AC-DC rectifier is usually not constant. In order to raise the DC-link voltage level, in traditional we prefer to add a DC-DC converter between the rectifier and inverter. Unique impedance circuit of Z-source inverter could be used as DC-DC converter, which has capability of boosting the DC-link voltage by adding the short through states even the DC-link voltage is not constant. And there is not necessary to add dead time for Z-source inverter, which output current’s total harmonic distortion (THD) is lower. This paper implements the AC-DC-AC converter for Permanent magnet synchronous generator using the diode rectifier and Z-source inverter. The AC load is three phase inductive and resistive load. Traditional voltage source inverter and Z-source inverter are introduced and compared with each other.
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Chen, Jia-Cing, and 陳嘉慶. "Development of a Novel Modulation Strategy for Quasi-Z-source Inverter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/36w2eu.
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碩士國立臺灣科技大學
電機工程系
104
In this thesis, the design and implementation of a novel modulation strategy for Quasi-Z-source inverter (qZSI) is first presented. The developed qZSI features high compactness, low component and thermal stresses, continuous input current and can simultaneously carry out both DC voltage boost and DC-AC inversion. Based on the realized qZSI, a modified qZSI sinusoidal pulse-width modulation (qZSPWM) strategy is proposed. Instead of placing the shoot-through state in both inverter legs, the proposed method generates the shoot-through state only in left/right inverter leg during the positive/negative cycle, respectively. Using this way, the switching losses and thermal stress of the power devices can be reduced. To further improve the efficiency, a new shifted shoot-through state placement method is also studied. This method can reduce the switching numbers of power devices; hence further decrease the switching losses. In order to validate the correctness of the proposed methods, a 110Vac, 60 Hz, 350 W prototyping circuit is built. According to the experimental results, the measured conversion efficiencies of the designed system are higher than 88.5 %. Comparing with conventional qZSI with simple-boost control, at the same loading condition, the proposed modulation technique can improve the maximum efficiency by 3.4 %.
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Shen, Miaosen. "Z-source inverter design, analysis, and its application in fuel cell vehicles." Diss., 2006.
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Thesis (Ph. D.)--Michigan State University. Dept. of Electrical and Computer Engineering, 2006.Title from PDF t.p. (viewed on Nov. 17, 2008) Includes bibliographical references (p. 168-175). Also issued in print.
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Jhang, You-Fang, and 張又方. "A Z-source Photovoltaic Inverter with Simplified Short Circuit Interval Control Method." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/74863628139078155435.
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碩士東南科技大學
電機工程研究所
102
This thesis develops a single-phase Z-source photovoltaic inverter which can convert the DC power of solar cells into AC power for home appliances. The Z-source Inverter solves the problem of reducing efficiency result from traditional multi-level inverter. Only need to use the combination of two inductors and capacitors and coordinate with the short time control of full bridge switches. The circuit achieves the purpose of boosting effect, reducing the system cost at the same time. Because the boost control of traditional Z-source converter takes the extra DC value comparison method to adjust the short circuit interval whose control method is more complicated and hard to realized, thus this research addresses a simplified boost control method by adjusting the overlapped conduction time of the upper arm and the lower switches to control the boost factor. Besides, this thesis provides more rapid and correct guidance for the selections inductors and capacitors of which bases on principle of Z-source circuit. In order to verify the feasibility, this research uses a TI 32-bit digital signal processor TMS320F2808 to implement a full digital photovoltaic Z-source inverter. This system via cross measurement analysis comes from the conditions of different voltage, different inductors and capacitors to confirm the simplified boost control methods can achieve the boosting function of Z-source circuit and according to the elements of inductors and capacitors result from parameter formula can prove this system will get the optimized effect of boost.
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Chen, Hsueh-Min, and 陳學敏. "Implementation of a Single-Phase Z-Source Inverter for Grid-Connected Photovoltaic Systems." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/08556935810955840287.
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碩士東南科技大學
電機工程研究所
99
This thesis studies a single-phase grid-connected photovoltaic system based on a Z-source inverter. The system directly converts the DC power generated by the photovoltaic modules into AC power and connects to the utility power system. Moreover, Z-source inverter is a single-stage topology, so its efficiency could be higher than other multi-stage systems. When the sun moves during a day or cloud cover changes, the system makes use of the buck-boost feature of the Z-source and applies the maximum-power-point-tracking scheme to output the maximum power of the photovoltaic modules. In addition, the system is based on a 32-bit digital signal processor TMS320F2808 to realize a full digital photovoltaic power system. Because the system only uses the PWM generator of the DSP TMS320F2808 to output all the Z-source trigger signals, it does not need the extra digital circuit hardware and the cost of system is decreased. Finally, the experimental results show that the system could work on a wide voltage range from 130-300 volts. The maximum output power of the system is up to 1kWatt and the efficiency of the system can reach to 97%. It is very suitable to apply to small power of solar power system.
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Lin, Kuen-Shian, and 林坤賢. "Investigation of Different Modulation Methods for Three-Phase Z-Source Inverter and FPGA Realization." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/02679182034983502403.
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碩士國立高雄應用科技大學
電機工程系博碩士班
101
This thesis analyzes and discusses the modulation methods for three phase z-source inverter. The z-source inverter employs a unique impedance network and shoot-through state to boost the DC voltage and improve the drawback of traditional inverter. In this thesis, the modulation methods for sinusoidal pulse width modulation and space vector modulation are discussed, in both modulation techniques using three control methods,which are respectively simple boost control, maximum boost control, and maximum constant boost control, to achieve the boost effect. The simulation results of MATLAB/Simulink/SimPowerSystems are used to compare the boost effect and differences of each modulation method. The control module is made in Xilinx ISE software, and downloaded to FPGA developer board for verifing its feasibility.
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Wu, She-Zhen, and 吳攝展. "Study and Implementation of a High Step-up Multilevel Inverter with Z-source Impedance." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/fafv6q.
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碩士國立臺北科技大學
車輛工程系
106
The main objective of this study is to develop a novel modified Z-source multilevel inverter system with high step-up. The power converter includes two-stage conversion circuits. The pre-stage is a modified Z-source converter with the coupled-inductor and charge-pump techniques, and the second-stage is a hybrid cascaded H-bridge multilevel inverter. The features of the proposed system: (1) The pre-stage topology uses only a single DC-source input and one MOSFET switch, to deliver the energy to two isolated voltage outputs, making the simple circuit and low cost can be achieved. (2) The second-stage topology is constructed by two H-bridge modules, and the low harmonic voltages are obtained by using a particular pulse width modulation (PWM) method. (3) This topology can be extended to the higher number of voltage levels by adding multiple secondary windings along with the corresponding coupled-inductor and charge-pump circuits. The operating principle, component voltage stresses, modeling and the closed-loop control design are derived in detail in this study. Finally, an inverter system was implemented to verify the feasibility.
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Lin, Kuan-yu, and 林冠宇. "Design and Implementation of a Quasi Z-source Inverter for Stand-alone Photovoltaic Systems." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/57047877834050122295.
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碩士國立臺灣科技大學
電機工程系
101
The design and implementation of a quasi-Z-source inverter (qZSI) for standalone photovoltaic generation systems (PGSs) is proposed in this thesis. The qZSI is derived from the traditional Z-source inverter, which can realize both DC voltage boost and DC-AC inversion simultaneously in a single stage. The advantages of using qZSI for standalone PGS include compactness, low cost, and higher reliability. In addition, qZSI offers several advantages over the ZSI, including lower component rating and continuous input current. For a standalone PGS, maximum power point tracking (MPPT) and stable output voltage are two main objectives of the system. However, there are two control variables, i.e. the shoot-through duty ratio (Bduty) and modulation index (ma), in a qZSI system. Therefore, a novel control scheme is also proposed in this paper to achieve both MPPT and voltage control in the same time. The MPPT method implemented in this thesis is a commonly utilized perturb and observe (P&O) method. In addition, a novel Bduty placement method is proposed to reduce the thermal stress of the power device. In order to validate the correctness of the proposed methods, a 110 VAC, 60 HZ, 500 W prototyping circuit is built. According to the simulation and experimental results, the measured conversion efficiency of the design system are all higher than 91 %, and the measured MPPT tracking accuracies are all higher than 97 % for all tested conditions. In addition, the proposed control scheme can regulate the shoot through duty ratio and the modulation index to achieve MPPT and maintain the output voltage magnitude simultaneously.
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CHEN, JUN-YAN, and 陳俊諺. "Study and Implementation of a Fifteen Level Inverter with Coupled-Inductor and Single Input Z-Source Impedance." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/23ea7u.
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碩士國立臺北科技大學
車輛工程系
107
This paper proposes a newly multilevel inverter for converting the DC distributed energies (such as batteries, solar cells, fuel cells, etc.) to AC load power supply. In this thesis, the key technologies are to integrate the coupled-inductor, charge pump, and Z-source impedance into the pre-stage, the DC/DC step-up converter. Besides, we use the hybrid pulse width modulation method for the post-stage, the cascaded full-bridge 15-level inverter. In spite of the traditional multilevel inverter need the separate multi-input sources as the input voltage source, the proposed multilevel inverter with only one single input power source to achieve the advantages of low cost, high power density, and low harmonic AC voltage output. Finally, to verify the feasibility of the proposed concept, we built a 500W inverter prototype to check the simulation and experiment results. The input and output voltages of the proposed multilevel 500W inverter are 48V and 110Vrms, respectively. The maximum efficiency of 91% for the pre-stage converter under 300W condition, and the maximum efficiency of 93%, the THD of 2.1% for the 15-level inverter under 100W output condition, can be achieved.
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Cai, Jhong-Bin, and 蔡忠彬. "Implementation of a Single-Phase Quasi Z-Source Inverter with Indirect Current Control Algorithm for a Reconfigurable PV System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6s77v3.
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碩士國立高雄應用科技大學
電機工程系博碩士班
102
Based on a single-phase Quasi Z-source inverter and the grid-connected system, a reconfigurable PV system was built. A Digital Signal Processor (DSP) is used to implement the indirect current control algorithm of Quasi Z-source inverter. The DC bus and the output voltage can be effectively regulated by shoot-through and non-shoot-through modes; then, the zero-point detector circuit with PLL control and power control is used to facilitate the parallel connection of the inverter to grid. In addition,when the grid is in fault condition, the system can regulate voltage amplitude and the power angle by transferring the grid-connected mode to the island mode and employing indirect current control algorithm. Through out the simulations by MATLAB/Simulink, the feasibility of the system model and control algorithm were verified. Finally, a prototype of Quasi Z-source inverter was built up and tested. The results illustrate that the parallel connection of inverter to grid can be satisfied, and the independent operation mode can be also implemented through the indirect current control algorithm under the condition of smooth transformation.
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Gu, Yu-Song, and 辜昱崧. "Implementation of a Single-Phase Quasi Z-Source Inverter with Voltage Dip Mitigation for a Grid Connected PV System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/61730302081156937415.
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碩士國立高雄應用科技大學
電機工程系博碩士班
101
Based on single-phase Quasi Z-source inverter, a grid-connected PV system was built; besides, a Digital Signal Processor (DSP) is used to implement the power control and improve the voltage quality problem caused by voltage dip. The zero-point detector circuit by PLL control is used to facilitate the parallel connection of the inverter to grid; in the meantime, the DC bus and the output voltage can be effectively regulated by shoot-through and non-shoot-through modes. In addition, the power angle and the voltage amplitude are used to regulate active and reactive power injected to the utility. To verify the feasibility of the system, the system model was built by MATLAB/Simulink, and the operation of the system was simulated. Finally, a prototype of Quasi Z-source inverter was tested, and the results illustrate that the parallel connection of inverter to grid and the power control of the system can be satisfied.
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Kottra, Marton. "2-Level Impedanz-Zwischenkreisinverter für einen Fahrmotor in elektrisch angetriebenen Fahrzeugen." Master's thesis, 2010. https://tud.qucosa.de/id/qucosa%3A29067.
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Wechselrichter im Antriebsstrang von Elektrofahrzeugen verbinden Batterie und Motor miteinander. Bei konventionellen Wechselrichtern ist die Ständerspannung des Fahrmotors durch die Batteriespannung begrenzt. Dies ist vor allem bei hohen Drehzahlen nachteilig, da hier ein zusätzlicher feldschwächender Strom notwendig ist. Dieser Strom wiederum verursacht zusätzliche Verluste in der Maschine und der Leistungselektronik. Einen alternativen Ansatz bieten hochsetzende Wechselrichter. Die Begrenzung der Ständerspannung durch die Batterie entfällt. In der vorliegenden Diplomarbeit werden zwei hochsetzende Wechselrichter miteinander verglichen.
Zunächst wird die Funktionsweise des Wechselrichters mit Hochsetzsteller und des ZSource-Wechselrichters erläutert. Danach werden Bauelemente für beide hochsetzende Wechselrichter ausgewählt. Anschließend werden die Verluste und das thermische Verhalten der ausgewählten Konfigurationen analysiert und mit Matlab simuliert. Abschließend werden der Wechselrichter mit Hochsetzsteller und der Z-Source-Wechselrichter bezüglich der Kriterien Wirkungsgrad, Zuverlässigkeit und Fertigungsaufwand miteinander verglichen.Inverter in the drive train of electric vehicles connect the battery to the machine. Using conventional inverters, the stator voltage is limited by the battery voltage. This is mainly a disadvantage at a high speed, since an additional field weakening current is needed. This current produces extra losses in the electrical machine and the power electronics. DC/DC boosted inverters offer an alternative solution. A limitation of stator voltage through the battery does not occur. This diploma thesis is comparing two kinds of DC/DC boosted inverters. First the functionality of an inverter with boost converter and that of a Z-Sourceinverter are presented. Afterwards the electrical components for both inverters are chosen and are simulated using Matlab. Finally the results of the simulation are compared with respect to power effciency, reliability of the electrical components and the effort of production.
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Pina, Manuel António de. "Sistema Fotovoltaico Ligado à Rede Usando um Conversor Multinível Quasi-Z do Tipo T." Master's thesis, 2021. http://hdl.handle.net/10400.26/35682.
Full textAbstract:
Os inversores quasi-Z de três níveis (qZS) baseados na topologia tipo T são especialmente indicados para uso em sistemas fotovoltaicos conectados à rede. Na verdade, apresentam uma característica importante para este tipo de aplicação, pois apresentam a característica redutor/elevador. Além disso, também é caracterizado por alta confiabilidade e operação multinível. Porém, associados a este conversor, devem ser utilizados controladores que garantam seu melhor desempenho. Neste contexto, esta dissertação irá propor um sistema de controlo global para o inversor trifásico tipo T qZS em um sistema fotovoltaico conectado à rede. Assim, será considerado um algoritmo rastreador de máximo ponto de potência (MPPT) baseado em uma abordagem derivada de tempo integral robusta. Para as correntes de saída será utilizado um controlador de corrente desacoplado no qual será associado um modulador por largura de pulso sinusoidal (SPWM). O desempenho do sistema será verificado e testado por estudos de simulação. Os resultados mostrarão que este sistema fornecerá resultados bem-adaptados para esta aplicação.Three-level quasi-Z-Source (qZS) inverters based on the T-Type topology are especially indicated to be used in grid-connected PV systems. In fact, they present an important feature for this type of application since presents Buck-Boost characteristic. Besides that, is also characterized by high reliability and multilevel operation. However, associated to this converter, it must be used controllers that will ensure their best performance. In this context, this thesis will propose a global control system for the three phase T-Type qZS inverter in a grid-connected PV System. So, it will be considered a MPPT algorithm based on a robust integral time derivative approach. For the output currents will be used a decoupled current controller in which will be associated to a SPWM modulator. The performance of the system will be verified and tested by simulation studies. The results will show that this system will provide results well adapted for this application.
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CHANG, FU-CHENG, and 張富程. "Three-Phase Quasi Z-Source Inverters with FPGA Implementation." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/26dcxj.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系博碩士班
104
This paper investigates the space vector modulation (SVM) for two-level and three-level Quasi Z-Source inverters (qZSI). The qZSI uses a unique impedance network and shoot-through state to achieve output line-to-line voltage can be higher than input voltage, overcome the limitation of traditional voltage-source inverters. When SVM applied to qZSI, the switching sequence must be modified to add the shoot-through state and only change partial or full of the zero state but can’t affect active state. Discussed the modifications of two-levl and three-level SVM in detail. Simulation results from MATLAB/Simulink/SimpowerSystems are used to validate the theoretical analysis. Finally, the ALTETRA Quartus II is used for design the switch excitation signals, then the code is downloaded to a FPGA board DE2-115. The MOSFET-based two-Level and three-level Quasi Z-Source inverter are implemented and experimental results verify the feasibility.
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Yang, Ting Ou, and 歐陽霆. "A novel Space Vector Modulation strategy for quasi-Z-source inverters." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6djxmw.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
105
Quasi-Z-source inverter (qZSI) features high compactness, low component and thermal stresses, continuous input current and the capability of simultaneously carry out both DC voltage boost and DC-AC inversion. For qZSIs, sinusoidal pulse width modulation (SPWM) method is typically applied. Comparing with SPWM, space-vector PWM (SVPWM) has advantages such as low current harmonics and high voltage utilization; hence, the traditional space-vector concept has been modified to be applicable for the qZSI in the literatures. In this thesis, a novel SVPWM strategy for qZSIs is presented. Instead of placing the shoot-through state in both inverter legs, the proposed method generates the shoot-through state only in left/right inverter leg during the positive/negative cycle, respectively. Using this way, the voltage distortion of the conventional SVPWM qZSI can be reduced. In order to validate the correctness of the proposed methods, a single-phase 110 Vac, 60 Hz, 350 W prototyping circuit is built. According to the experimental results, the measured conversion efficiencies of the designed system are all higher than 93.95 %. Comparing with the conventional qZSI using SVPWM control, the proposed modulation technique can improve the averaged conversion efficiency and voltage distortion by 0.482% and 1.125 %, respectively.
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Zhang, You-Cheng, and 張祐誠. "Simulation and Implementation of Three Level Z-Source Inverters with Space Vector Modulation Method." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/61734789392372615346.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系博碩士班
103
The Z-source inverter employs a unique impedance network and shoot through state to achieve boost voltage that overcome the limitations of the traditional voltage-source inverter. This thesis investigates the space vector modulation method for three-level Z-source inverters. Through the detailed study of shoot through state design and adopt an optimized switching sequence arrangement, this gives the benefit of without extra switching loss and lower output harmonic distortion. The proposed technique is demonstrated in simulation results from MATLAB/ Simulink/SimPowerSystems. Then, the ALTERA Quartus II software is used for constructing the control module of three level space vector modulation, and download the program to FPGA development board. A MOSFET-based three level Z-source inverter is implemented and verified the feasibility.