diplomsko delo
Klemen Plevnik (Author), Rastko Fišer (Mentor)

Abstract

Visokonapetostni enosmerni prenos (HVDC) omogoča prenašanje električne energije z manjšimi izgubami kot visokonapetostni izmenični prenos (HVAC). Hkrati je pri HVDC sistemu potrebno manj vodnikov za postavitev prenosne linije enake prenosne moči kot pri HVAC sistemu. Vsaka HVDC linija potrebuje dve pretvorniški postaji (usmernik in razsmernik), filtre za glajenje napetosti in toka ter enosmerni tokokrog, ki se ga realizira preko nadzemnega daljnovoda ali kabelske povezave (pod zemljo ali pod morjem). Začetna investicija je zaradi pretvorniških postaj dokaj velika in se zaradi visoke cene pretvorniških naprav uporablja le za daljše povezave, ko zaradi zmanjšanja izgub in števila vodnikov postane cenejša od HVAC povezave. Za prenašanje velikih moči se v pretvorniških vezjih uporablja tiristorske ventile, saj so zmožni prenašati največje moči. Za sisteme, kjer ni potrebno prenašati tako velikih moči, pa se zaradi boljših dinamičnih lastnosti uporablja IGBT ventile, kar posledično zmanjšuje harmonske komponente. Najbolj uporabljan tip HVDC povezave je v zadnjem obdobju bipolarna HVDC povezava. Povezava uporablja dva vodnika, enega s pozitivno in drugega z negativno polariteto. Multiterminalni HVDC sistem je še vedno dokaj redko izveden, vendar pa je njegov koncept vedno bolj uporabljan, saj omogoča vezavo več pretvorniških postaj na eno samo enosmerno omrežje in tako deluje kot običajen HVAC prenosni sistem. Mejna razdalja, kjer je investicija v HVDC sistem bolj ekonomična kot v HVAC sistem, je danes pri razdalji nad 500 km, oziroma za izvedbo s kabelskim prenosom pri 50 km. Razvojni izzivi za prihodnost HVDC prenosa so predvsem uporaba mutiterminalnih povezav, zmanjšanje izgub v enosmernemu sistemu in razvoj novih polprevodniških ventilov za nove generacije pretvorniških postaj.

Keywords

prenos električne energije;visokonapetostni enosmerni prenos;HVDC;močnostna elektronika;pretvorniki;visokošolski strokovni študij;Aplikativna elektrotehnika;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FE - Faculty of Electrical Engineering
Publisher: [K. Plevnik]
UDC: 621.31(043.2)
COBISS: 168575491 Link will open in a new window
Views: 43
Downloads: 5
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary title: High voltage direct current systems for electrical power transmission
Secondary abstract: High-voltage direct current (HVDC) transmission enables electric energy to be transmitted with lower losses compared to high-voltage alternating current (HVAC) transmission. At the same time, HVDC system requires fewer conductors to achieve the same transmission capacity as HVAC system. Each HVDC line requires two converter stations (rectifier and inverter), filters to smooth the voltage and the current, and a DC circuit, which is conducted via an overhead transmission line or cable connection (underground or undersea). The initial investment is relatively high due to the converter stations. HVDC is used primarily for longer connections when it becomes more cost-effective than HVAC due to reduced losses and the number of conductors. Thyristor switches are used to transmit high power in converter circuits due to their capacity of carrying the highest power levels. In systems that do not require the transmission of such power levels, IGBT switches are used due to their superior dynamic properties, which consequently reduces harmonic components. Currently, the most widely used type of HVDC link is the bipolar HVDC link. The connection uses two conductors, one with positive and one with negative polarity. The multi-terminal HVDC system is still quite rarely implemented, but its concept is increasingly used, as it allows the connection of several converter stations to a single DC grid, thus acting as a conventional HVAC transmission system. The break-even distance, where the investment in an HVDC system is more economical than in an HVAC system, is currently at distances above 500 km, or up to 50 km for the implementation with cable transmission. Future challenges of HVDC transmission include the use of multi-terminal connections, the reduction of losses in the DC system and the development of new semiconductor switches for the new generations of converter stations.
Secondary keywords: HVDC;Directional current transmition;Power electronics;converter;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000315
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za elektrotehniko
Pages: XIV, 67 str.
ID: 19933582