Povratni napon na prekidaču pri isklopu kratkog spoja na 400 kV vodu

master's thesis

• Title (english): Transient recovery voltage on circuit breaker due to 400 kV line fault
• Author: Anđela Šarić
• Mentor: Viktor Milardić (mentor)
• Committee member: Viktor Milardić (predsjednik povjerenstva)
• Committee member: Božidar Filipović-Grčić (član povjerenstva)
• Committee member: Goran Grdenić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2024-07-12, Croatia

Abstract

Ovaj rad istražuje povratni napon na prekidaču pri isklopu kratkog spoja na 400 kV vodu, ključno pitanje u visokonaponskim elektroenergetskim sustavima. Kratki spojevi mogu izazvati značajne prijelazne napone koji utječu na prekidače, što može ugroziti stabilnost i pouzdanost cijelog sustava. Analizirani su osnovni pojmovi kratkog spoja, karakteristike prekidača te priroda prijelaznog povratnog napona.
Posebna pažnja posvećena je faktorima koji utječu na veličinu i trajanje povratnog napona, kao što su vrsta i trajanje kratkog spoja, svojstva prekidača. Također su spomenute različite metode za smanjenje negativnih učinaka povratnog napona, uključujući uporabu odvodnika prenapona, optimizaciju dizajna prekidača, smanjenje impulsnih impedancija te primjenu zaštitnih releja.
Zaključno, napravljen je model dalekovoda 400 kV Velebit – Melina te je provedena analiza povratnog napona na prekidaču s obzirom na mjesto kratkog spoja, fazni kut izvora te otpor kratkog spoja. Također je obraćena pažnja i na strminu početnog prijelaznog napona.

Abstract (english)

This paper investigates the back voltage on a circuit breaker during the interruption of a short circuit on a 400 kV transmission line, a critical issue in high-voltage power systems. Short circuits can generate significant transient voltages that have the potential to compromise the stability and reliability of the entire system. We have analyzed the fundamentals of short circuits, characteristics of circuit breakers, and the nature of transient recovery voltage.
Special attention has been paid to factors influencing the magnitude and duration of the back voltage, such as the type and duration of the short circuit, and properties of the circuit breaker. The study thoroughly examines methods to mitigate the adverse effects of back voltage, including the use of surge arrestors, optimization of circuit breaker design, reduction of impulse impedance, and the application of protective relays.
Additionally, a model of the 400 kV Velebit – Melina transmission line was employed to analyze back voltage at the circuit breaker considering the location of the short circuit, phase angle of the source, and short circuit resistance. This analysis provides specific insights into the dynamics of back voltage in real-world high-voltage power systems.
Looking forward, continuous monitoring and improvement of back voltage control methods will be crucial to maintaining the safety and reliability of electrical grids, ensuring stable electricity supply under all conditions.

• Keywords: povratni napon na prekidaču; struja kratkog spoja; dalekovodi
• Keywords (english): transient recovery voltage; short circuit current; transmission lines
• Language: croatian
• URN:NBN: urn:nbn:hr:168:888481
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije (magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2024-10-12 22:13:34