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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.
11

Sensitivity Analysis of Synchronous Generators for Real-Time Simulation

Munukuntla, Sowmya 13 May 2016 (has links)
The purpose of this thesis is to validate generator models for dynamic studies of power systems using PSS/E (Power System Simulator for Engineering), EMTP (ElectroMagnetic Transient Program), and Hypersim. To thoroughly evaluate the behavior of a power system in the three specified software packages, it is necessary to have an accurate model for the power system, especially the generator which is of interest. The effect of generator modeling on system response under normal conditions and under faulted conditions is investigated in this work. A methodology based on sensitivity analysis of generator model parameters is proposed aiming to homogenize the behavior of the same power system that is modeled in three software packages. Standard IEEE 14-Bus system is used as a test case for this investigation. Necessary changes in the exciter parameters are made using the proposed methodology so that the system behaves identical across all three software platforms.
12

Digital Control Of Solar Photovoltaic Converters

Srinath, R 12 1900 (has links)
A photo-voltaic system consists of solar cells, power converters, battery and the load. The power converter interfaces the solar cells, battery and the load. The battery serves to equalise the energy demand (load) and the energy supply (solar cell). Currently the solar cells and the battery cost nearly 90% of the system cost. A typical photo-voltaic system can adopt various power bus configurations. Battery tied bus is the simplest of the power bus configurations. In this topology, the battery is always attached to the bus. This system is extremely simple in terms of power circuit configuration as well as control. Such systems weigh less and are more reliable. However, the battery tied bus suffers certain disadvantages. The first among them is the poor utilisation of solar panels. The load has to tolerate the full swing of the battery voltage variation. On account of the constraint on the solar panel voltage, the solar panels may not be loaded to the maximum power capacity. Such operating conditions lead to gross under-utilisation of the expensive solar panels. The battery tied bus configuration is designed, built and evaluated experimentally with 4 solar panels rated at 35 W each and a lead acid battery of 12 V 42 AH rating. This thesis explores alternate power architecture to overcome the above limitations. Load regulation and maximum power harvesting from the solar panels are the objectives. In the proposed configuration, a bidirectional power converter is inserted between the bus and the battery. The bidirectional power converter operates in boost mode and charges the battery when the sunlight is available. During eclipse period, it operates in buck mode and meets the load demand. The maximum power is extracted from the panels by controlling the voltage across the solar panels. The bus voltage reference is computed by MPPT block and the bus voltage is regulated to the reference voltage through closed loop control. So the maximum power is extracted from the panels at the expense of extra bidirectional power converter. Even though there is an additional power loss due to the introduction of power converter, this power bus configuration is superior because it increases the output power from the panel itself. The entire control logic implementation is done digitally using dspic30F6010A. The simulation is done by writing script files in C language. The proposed bus configuration is designed, built and evaluated experimentally with the same setup and the results are then compared.
13

Návrh systémové elektroinstalace sportovní haly / Design of system wiring of sports hall

Jaroš, Zdeněk January 2020 (has links)
This diploma thesis focused on designing of systematic wiring of multifunctional sports centrum. The work is divided into two parts. The first part of the work is dealing with definitions and principles necessary for electrical project documentation. There is a presentation of the KNX bus control system, which is chosen for the implementation of the systematic wiring of the sports centrum. There is also an overview of currently used systems for wiring control. At the end, the design of artificial and emergency lighting is processed using a computer program. The content of the second part of the work is a complete project documentation for construction of the multifunctional sports hall using the KNX bus system. Furthermore, the documentation draws the design of power and data distribution to the relevant floor plans of the building, the design of power and system switchboards, an overview scheme of power distribution, topology of the KNX system, budget and technical report.
14

Využití moderních inteligentních elektroinstalací pro osvětlení budov / Use of modern inteligent wiring for building lighting

Hlinecký, Tomáš January 2009 (has links)
This diploma thesis concerns with problematic of modern intelligent wiring systems in buildings, meanwhile presents their advantages against old classical wiring systems. Also deals with utilization and properties of modern components for regulation, switching and light controlling. The first part deals with light sources and possible ways how to control the power of individual luminary sources. The second part discuss about utilization of radio-frequency systems in new buildings and also in reconstructions. In the next part is described a possibility of bus system for controlling building illumination scope with focusing to control system Nikobus. The last part is concerned on technical-economical evaluation of intelligent wiring systems by various manufacturers according to specific requirements.
15

Evaluation of Symmetrical Components Theory in Power Systems with Renewable Sources

Danylov, Daniil January 2021 (has links)
Rapidly growing Inverter- Based Resources (IBR) have different fault properties compared to Synchronous Generators (SG). Therefore, it is necessary to study the fault behavior of systems that contain different types of IBR and compare it to the conventional system responses in order to understand what steps should be taken to adapt conventional protection settings for new types of sources. For a two bus model, it is found out that sequence profiles in a system with one IBR are different from those observed in conventional system. Thermal and electrical limitations of the power electronics reduce the fault current from the IBR significantly, driving negative sequence current to small values compared to conventional sources. This is true for all studied types of IBR. Moreover, if IBR is connected to the grid through one line only, during Three Phase Fault (3hp) it is possible to lose synchronism with grid due to erroneous estimation of the grid angle through the Phase-Locked Loop (PLL). Verification of the obtained results is made through comparison to the Fault Recordings taken from the protection relays placed at substations. It is shown that for some faults simulation results can predict the behavior of symmetrical components in the network whereas for others they do not. To explain the latter behavior modifications to the sequence networks are proposed. / Snabbt växande inverterbaserade resurser (IBR) har olika felinmatningsegenskaper jämfört med synkrongeneratorer (SG). Därför är det nödvändigt att studera felbeteende hos system som innehåller olika typer av IBR och jämför det med konventionella källor för att kunna förstå vilka steg som ska göras för att anpassa konventionella skyddsinställningar för nya typer av källor. Under litteraturöversikten introduktion till det fast jordade systemet och dess speciella fall med isolerad transformatorjordning är klar. Kort introduktion till den studerade IBR och typer av simulerade fel görs också. För en tvåbussmodell har det visat sig att sekvensprofiler i ett system med en IBR skiljer sig från de som observerats i konventionella system. Termisk och elektrisk begränsningar i kraftelektroniska komponenter minskar felströmmen från IBR avsevärt och driver negativ sekvensström till små värden jämfört med konventionella källor. Detta gäller för alla studerade typer av IBR. Dessutom, om IBR är ansluten till nätet endast genom en linje, är det möjligt under trefasfel (3hp) att tappa synkronisering med nätet på grund av felaktig uppskattning av fasvinkeln genom styrsystemets faslåst slinga (PLL). Verifiering av de erhållna resultaten görs genom jämförelse med Fel Inspelningar från reläet placerade på transformatorstationer. Det visas att för vissa fel simuleringsresultat kan förutsäga symmetriska komponenters beteende i nätverket medan andra inte gör det. För att förklara de senare beteendena föreslås modifieringar i sekvensnätverket.

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