Podnaponsko rasterećenje elektroenergetskog sustava

scientific master's theses

• Title (english): Undervoltage load shedding of power systems
• Author: Mario Klarić; VIAF: 305677577
• Mentor: Sejid Tešnjak (mentor)
• Committee member: Igor Kuzle (predsjednik povjerenstva)
• Committee member: Sejid Tešnjak (član povjerenstva)
• Committee member: Matislav Majstrović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Energy and Power Systems); Zagreb
• Defense date and country: 2006-12-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Power Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

U magistarskom radu prikazano je podnaponsko rasterećenje kao mjera sprečavanja potpunog raspada elektroenergetskog sustava. U uvodnom dijelu dat je pregled osnova stabilnosti sustava osobito naponske stabilnosti. Također, opisan je mehanizam naponskog sloma. U posljednjih nekoliko godina u svijetu se dogodio velik broj slučajeva raspada elektroenergetskih sustava uzrokovanih naponskom nestabilnošću i naponskim slomom. Najznačajniji primjeri takovih raspada dogodili su se u SAD-u i Italiji 2003. te su isti slučajevi opisani i analizirani u ovom radu. Opisan je i utjecaj liberalizacije elektroenergetskog sektora koja je u tijeku posljednjih desetljeća i koja se negativno odrazila na broj i veličinu ovakvih incidentnih situacija. Sve veći tranziti snaga odvijaju se na sve veće udaljenosti što se u konačnici negativno odražava na stabilnost sustava. Napovoljnije rješenje za ovu vrstu problema je izgradnja novih prijenosnih i proizvodnih postrojenja. To je vrlo skup proces i često vrlo dugotrajan pa se podnaponsko rasterećenje elektroenergetskog sustava nameće se kao jeftino i pouzdano rješenje ovih problema. Također, vrlo brzo se implementira u sustav i može služiti kao privremeno rješenje prije izgradnje novih potrebnih postrojenja. Jednako tako, može služiti kao lokalna zaštita sustava od naponskog sloma odnosno kao mjera sprečavanja širenja naponske nestabilnosti kroz sustav. U ovom magistarskom radu prikazano je nekoliko slučajeva naponskih slomova koji su se dogodili u svijetu. Također, dat je opis mjera podnaponskog rasterećenja koje su trenutno u primjeni u elektroenergetskim sustavima, ponajprije u SAD-u. Ukratko je opisan i utjecaj podnaponskog rasterećenja na elektroenergetska postrojenja. Podnaponsko rasterećenje simulirano je u programskom paketu ETAP na nekoliko slučajeva i to na New England testnom sustavu te na realnom sustavu Hrvatske elektroprivrede. Prvotno je simuliran naponski slom, a potom i njegovo sprečavanje instaliranjem podnaponskih releja u najkritičnija čvorišta. Pokazano je kako ova mjera može spriječiti potpuni raspad elektroenergetskog sustava isključivanjem opterećenja na najugroženijim mjestima. Na taj način sprečava se gubitak ostalih opterećenja i smanjuje šteta uzrokovana nestankom električne energije. Dat je pregled prednosti i nedostataka ovakve vrste zaštite elektroenergetskog sustava od potpunog raspada. Također, analizirane su moguće nadogradnje i poboljšanja sustava podnaponskog rasterećenja.

Abstract (english)

In this thesis, undervoltage load shedding is presented as a measure for preventing total blackout of power systems. In the introduction, basics of power system stability are given where voltage stability is emphasized. Also, the mechanisam of voltage collapse is shown as well. In the last few years in the world, a large number of power system blackouts has occurred caused by voltage instability and voltage collapse. The most significant examples of such blackouts have happened in the USA and taly in 2003 and these cases are described in this thesis. The influence of power sector liberalization is described as well especially its negative impact on the number and size of such incidents. Larger and larger amounts of power are being transfered to greater and greater distances which has negative impact on power system stability. The most suitable solution for this kind of problem is building of new transmission and production facilities. It is very expensive and often very long process so undervoltage load shedding of power system imposes as economic and reliable solution of these problems. Also, it can be very fastly implemented into the system and it can serve as a temporary solution before building of new necessary facilities. It can also serve as local protection against voltage collapse and as a measure of further voltage instability widespreading through the system. In this thesis few cases of voltage collapse, which occurred in the world, are shown. Also, description of undervoltage load shedding measures currently in operation, primary in the USA, are given. Undervoltage load shedding influence on power system facilities is shortly described. Undervoltage load shedding is simulated in software package ETAP on the few cases which are New England test system and Croatian Power Utility transmission system. Firstly, voltage collapse is simulated on both systems, and afterwards its prevention by installing undervoltage relays in most critical buses. It is shown how can this measure prevent total power system blackout by shedding of loads in most endangered places. In this way, the lost of other loads is prevented and damege caused by power supply interruption is decreased. Advantages and disadvantages of this kind of power system protection is given. Also, possible upgrades and betterments of undevoltage load shedding system are analized.

• Keywords: elektroenergetski sustav; stabilnost sustava; naponska stabilnost; naponski slom; raspad elektroenergetskog sustava; podnaponsko rasterećenje
• Keywords (english): power system; system stability; voltage stability; voltage collapse; power system blackout; undervoltage load shedding
• Language: croatian
• URN:NBN: urn:nbn:hr:168:073881
• Study programme: Title: Postgraduate master programme in electrical engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: Magistar znanosti elektrotehnike (Magistar znanosti elektrotehnike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-12-20 09:42:43