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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design, Simulation and Modeling of Insulated Gate Bipolar Transistor

Gupta, Kaustubh 16 December 2013 (has links)
The market for Insulated Gate Bipolar Transistor (IGBT) is growing and there is a need for techniques to improve the design, modeling and simulation of IGBT. In this thesis, we first developed a new method to optimize the layout and dimensions of IGBT circuits based on device simulation and combinatorial optimization. Our method leads to the optimal IGBT layout consisting of hexagons, which is 6 % more efficient in terms of performance (current per unit area) over that of squares, and up to 80 % more efficient than rectangles. We also explored several techniques to reduce the time used for device simulation. In particular, we developed an accurate Verilog-A description based on the Hefner model. For transient simulation, the time used by SPICE on the Verilog-A model is only 1/10000 of that used by device simulation on the device structure. The SPICE results, though contain some inaccuracies in the details, match device simulation in the general trend. Due to the effectiveness and efficiency of our methods, we propose their application in designing better power electronic circuits and shorter turn-around time.
2

Framtagning av testutrustning för transistorer vid induktiv last.

Gunnarsson, Mathias January 2015 (has links)
When a transistor is used as a switch in a conversion of electrical energy, the switching losses are decisive in the choice of the transistor. In order to compare these losses, a test equipment has been developed, which can be used to perform measurements on different IGBT-transistors when switching an inductive load. The objective of this work was to develop a test equipment, and to use it to take measurements of a number of transistors. The equipment has been designed in such a way that the components that affect the switching losses can be replaced in a simple manner. Parameters like switched voltage and pulse duration of the gate signal can be adjusted as well. In this way, different components influence can be examined and measurements can be adjusted to mimic different net-voltages. Developed test equipment has been used to perform measurements of four different IGBT-transistors when turned off, and a comparison between fall times, energy consumption and switching losses have been made. Measurements have only been done on IGBT-transistors as fluctuations occurred during the measurements of the MOSFET. This is believed to be due to that the fall time of the MOSFET is significantly less than for the IGBT, which leads to an increase of the impact of the parasitic components. For measurement of the MOSFET the components needs to be placed closer to each other, to thereby reduce parasitic components. Such equipment means that the components can not be replaced in a simple manner, which was the purpose of the test equipment. Measurements and comparison has been carried out on four different IGBT-transistor. They show an opportunity to reduce switching losses through the replacement of the current transistor.
3

Modeling of IGBT Modules with Parasitics Elements Evaluation

Norouzian, Zahra January 2013 (has links)
The goal of this report is the development of a PSpice based modeling platform for the evaluation of power IGBT modules to be used in HVDC and FACTS applications. The use of simulation tools is of great value in the process of developing new power electronic devices and new converter topologies. By means of this proper model platform, new design ideas and better understanding of devices behavior and related physical phenomena of the modules can be easily estimated and the outcome is reducing the demand of extensive laboratory testing. Particularly important is the choice of a proper model capable of fast simulation times and adequate accuracy, while a challenging issue is to guarantee the convergence of such models given the hard nonlinearities and multiple cross-references involved. The choice of a Spice based simulation platform consisting in a circuitously based model, allows us to evaluate the characteristics of each module as a function of parameters like a dc-voltage, load current, stray inductance and gate driving.
4

DC to AC inverter card with IGBTs : Construction and performance

Eriksson, Johannes January 2012 (has links)
This paper presents the construction and evaluation of a DC to AC inverter with IGBT:s and the basic PCD-layout for the single IGBT drivers. The main work consisted of constructing a PCB-card for controlling a number of IGBT:s, simulate its properties and test driving it. The schematic of the card is an extension of the recommended use of the optocoupler HCPL316J with a few modulations made for the special demands on the Division of Electricity at Uppsala University. Even though, some basic changes were made in the schematic in this work, the main changes concerned choice of components due to economy and space and did not change the electrical properties of the card notably. Except several electrical properties that will be the main focus in this paper, size and price are two things that also have been taken under consideration during the work. In the paper, many parts and components will be described to fully explain the function of the cards properties. This is for future reference and documentation and was one of the goals of the project.
5

Entwurf und Simulation von Makromodellen zur transienten Simulation von thermo-elektrischen Kopplungen in einem Netzwerksimulator

Schacht, Ralph. Unknown Date (has links) (PDF)
Techn. Universiẗat, Diss., 2002--Berlin.
6

Investigation of Trench Gate IGBTs in MMC based VSC for HVDC

Tamil Selva, Kruphalan January 2018 (has links)
The following is a thesis project involving investigation of applicability of trench type IGBTs in present and future VSC based HVDC convertors. The work involves three major sections – theoretical loss evaluation of adoption of Trench technology (both IGBT and BIGT) for HVDC Light® applications, testing the Trench IGBT prototype with existing gate units and finalizing with a hypothesis and a practical solution for unexplained turn-on phenomenon observed during testing. The thesis concludes with the suggestion of suitable driving mechanisms (e.g. reduced number of current sources and removal of active gate snubbers) which shall result in both simpler and more cost effective driving compared to the present employed methods. / Följande avhandling är en studie om tillämpligheten av trench type IGBTer i nuvarande och framtida VSC baserade HVDC konverterare. Arbetet omfattar tre övergripande delar – teoretisk förlustberäkning vid tillämpning av trench teknologi (både IGBT och BIGT) till HVDC Light applikationer, prov av Trench IGBT prototyp med befintliga gate enheter och slutligen en hypotes och praktisk lösning till oförklarliga turn-on fenomen som observerats under prövning. Avhandlingen avslutas med en sammanfattning över lämpliga drivningsmekansimer (t.ex om antal strömkällor och borttagning av aktiv snubber vid gate enheten) som torde resultera både i enklare och kostnadseffektivare drivning jämfört metoder som tillämpas idag
7

A Circuit Model for Switching Loss Estimation in Voltage Source Converters

Naushath, Mohamed 02 August 2013 (has links)
Insulated Gate Bipolar Transistor (IGBT) based voltage source converter (VSC) applica-tions embedded in power systems are growing. Optimal design of thermal management systems for such converters requires estimation of IGBT losses under various operating conditions, both normal and abnormal. Therefore, development of tools for estimating IGBT losses in EMT simulators is important as converters embedded in large power sys-tems are simulated in EMT simulators. Two circuit models are developed to simulate turn-on and turn-off transients using a be-havioral approach. These circuit models mimic the observed behavior in distinct phases of the turn-on and turn-off transients under the inductive load switching. In this model, the nonlinear nature of the circuit model of the IGBT is treated and converter specific in-fluential parameters are taken in to account. An excellent correlation between the meas-ured and simulated waveforms as well as measured and estimated switching losses is ob-served. Finally, an efficient method to incorporate switching loss calculation in an EMT program in the form of a lookup table created using the developed transient model is pro-posed.
8

A Circuit Model for Switching Loss Estimation in Voltage Source Converters

Naushath, Mohamed 02 August 2013 (has links)
Insulated Gate Bipolar Transistor (IGBT) based voltage source converter (VSC) applica-tions embedded in power systems are growing. Optimal design of thermal management systems for such converters requires estimation of IGBT losses under various operating conditions, both normal and abnormal. Therefore, development of tools for estimating IGBT losses in EMT simulators is important as converters embedded in large power sys-tems are simulated in EMT simulators. Two circuit models are developed to simulate turn-on and turn-off transients using a be-havioral approach. These circuit models mimic the observed behavior in distinct phases of the turn-on and turn-off transients under the inductive load switching. In this model, the nonlinear nature of the circuit model of the IGBT is treated and converter specific in-fluential parameters are taken in to account. An excellent correlation between the meas-ured and simulated waveforms as well as measured and estimated switching losses is ob-served. Finally, an efficient method to incorporate switching loss calculation in an EMT program in the form of a lookup table created using the developed transient model is pro-posed.
9

Design Study of a Future 10kW Motor Controller / Designstudie av framtida 10kW växelriktare

Eidborn, Daniel January 2008 (has links)
This work has the approach for how an electric motor controller should be designed. In aircraft applications it is important that the system has a high power density, and that it is reliable. The target was to find out what is possible with technology of today, and with possibilities of tomorrow. The target is to be able to compare hydraulic systems with electrical ones. The type of controllers that was studied was controllers for permanent magnetized synchronous machines (PMSM). The reason for that choice is that PMSM has a high efficiency. Different transistor technologies were evaluated. Discrete IGBT was found to be the best option. Of the evaluated transistors has IRG4PSH71U operating with a SiC freewheeling diode the best efficiency. The benefit with discrete components is that they are easy to cool, for example if they are distributed on an aluminium heatsink with forced air cooling. To minimise losses and gain controllability on the motor should the inverter be controlled with some kind of vector control, such as DTC (Direct Torque Control). / I det här arbetet studerades hur en elmotorstyrning i ett flygplan bör konstrueras. I flygapplikationer är det viktigt att systemet är lätt i förhållande till effekten, och att det är tillförlitligt. Målet var att ta reda på vad man kan uppnå med dagens teknik, och även med kommande teknik. Syftet är att kunna jämföra hydrauliska system med elektriska. Det som undersöktes var motorstyrningar till permanentmagnetiserade synkronmaskiner (PMSM), eftersom dessa motorer har en hög verkningsgrad. Olika transistortekniker utvärderades. Diskreta IGBT fanns vara det bästa valet i en sådan applikation. Av de transistorer som jämfördes har IRG4PSH71U tillsammans med en frihjulsdiod av SiC den bästa totala verkningsgraden. Det vill säga att summan av ledningsförluster och switchförluster är lägst för den kombinationen. Fördelen med diskreta transistorer är att de har en lägre termisk resistans och kan spridas på en kylfläns, vilket underlättar kylningen, t.ex. med en aluminiumkylfläns med forcerad luft kylning. För att minimera förluster och öka styrbarheten på motorn bör växelriktaren styras med någon typ av vektor kontroll exempelvis DTC (Direct Torque Control).
10

Design Study of a Future 10kW Motor Controller / Designstudie av framtida 10kW växelriktare

Eidborn, Daniel January 2008 (has links)
<p>This work has the approach for how an electric motor controller should be designed. In aircraft applications it is important that the system has a high power density, and that it is reliable. The target was to find out what is possible with technology of today, and with possibilities of tomorrow. The target is to be able to compare hydraulic systems with electrical ones.</p><p>The type of controllers that was studied was controllers for permanent magnetized synchronous machines (PMSM). The reason for that choice is that PMSM has a high efficiency. Different transistor technologies were evaluated. Discrete IGBT was found to be the best option. Of the evaluated transistors has IRG4PSH71U operating with a SiC freewheeling diode the best efficiency. The benefit with discrete components is that they are easy to cool, for example if they are distributed on an aluminium heatsink with forced air cooling.</p><p>To minimise losses and gain controllability on the motor should the inverter be controlled with some kind of vector control, such as DTC (Direct Torque Control).</p> / <p>I det här arbetet studerades hur en elmotorstyrning i ett flygplan bör konstrueras. I flygapplikationer är det viktigt att systemet är lätt i förhållande till effekten, och att det är tillförlitligt. Målet var att ta reda på vad man kan uppnå med dagens teknik, och även med kommande teknik. Syftet är att kunna jämföra hydrauliska system med elektriska.</p><p>Det som undersöktes var motorstyrningar till permanentmagnetiserade synkronmaskiner (PMSM), eftersom dessa motorer har en hög verkningsgrad. Olika transistortekniker utvärderades. Diskreta IGBT fanns vara det bästa valet i en sådan applikation. Av de transistorer som jämfördes har IRG4PSH71U tillsammans med en frihjulsdiod av SiC den bästa totala verkningsgraden. Det vill säga att summan av ledningsförluster och switchförluster är lägst för den kombinationen. Fördelen med diskreta transistorer är att de har en lägre termisk resistans och kan spridas på en kylfläns, vilket underlättar kylningen, t.ex. med en aluminiumkylfläns med forcerad luft kylning.</p><p>För att minimera förluster och öka styrbarheten på motorn bör växelriktaren styras med någon typ av vektor kontroll exempelvis DTC (Direct Torque Control).</p>

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