Vgradnja Petersenove dušilke v razdelilno transformatorsko postajo Lenart

Wagner, Nejc (author), Pantoš, Miloš (mentor)

Distribucijsko podjetje Elektro Maribor d.d. se je ob izteku življenjske dobe in dotrajanosti opreme v razdelilni transformatorski postaji (RTP) 110/20 kV Lenart odločilo za prenovo 20 kV stikališča ter zamenjavo enega od dveh 110/20 kV energetskih transformatorjev, kasneje pa tudi drugega. Pri tem se je v RTP zamenjala vsa sekundarna oprema zaščite, vodenja, števčnih meritev ter meritev kakovosti električne energije. Za obvladovanje prehodnih zemeljskih stikov, so se odločili za uvedbo Petersenove dušilke, namenjene ozemljevanju srednje-napetostne nevtralne točke prej omenjenih transformatorjev. Po naročilu naročnika in investitorja so se izdelali vsi potrebni projekti za izvedbo (PZI) v zvezi s sekundarno opremo za trideset 20 kV celic, za dve 110 kV daljnovodni (DV) polji, za dve 110 kV transformatorski (TR) polji in za preostale potrebne omare, kot so omara meritev, omare lastne rabe, sistem daljinskega vodenja in nadzora, omarica avtomatov merilnih napetosti ter načrt resonančne ozemljitve srednjenapetostne (SN) nevtralne točke TR 1 in TR 2. V sklopu tega zaključnega dela so podrobneje predstavljeni naslednji načrti: načrt 20 kV shunt celice, načrt ozemljitve SN nevtralne točke TR 1 in TR 2 ter načrt ene izmed 20 kV izvodnih celic, za katero so tudi predstavljene zemeljskostične zaščite v odvisnosti od režima obratovanja nevtralne točke. Izdelavi PZI so sledili prevzem in prevzemni testi (angl. Factory Acceptance Test – FAT) Petersenove dušilke v tovarni EGE, spol. sr. o., Češke Budjejovice, kjer smo bili prisotni pri opravljanju nekaterih izmed testov, druge pa so člani EGE opravili sami in nam jih predstavili v obliki poročila. Po montaži dušilke in preostale opreme v RTP, se je izvedlo še teste, potrebne za preverjanje pravilnosti same montaže ter delovanja zaščitnih sistemov pred spuščanjem sistema v pogon (angl. Site Acceptance Test – SAT). Po uspešno opravljenem testiranju in strokovnem tehničnem pregledu se je Petersenova dušilka, skupaj z njenim sistemom regulacije, lahko varno ter zanesljivo spustila v pogon.

• Language: Slovenian
• Keywords: Petersenova dušilka, razdelilna transformatorska postaja, zemeljskostična zaščita, FAT, SAT
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FE - Faculty of Electrical Engineering
• Year: 2026
• PID: 20.500.12556/RUL-187255
• COBISS.SI-ID: 291767811
• Publication date in RUL: 09.09.2026

Secondary language

• Language: English
• Title: Installation of a Petersen Coil in the Lenart Distribution Substation

Abstract

The distribution company Elektro Maribor d.d. decided, due to end-of-life conditions and the deterioration of equipment, to refurbish the 20 kV switchgear and replace one of the two 110/20 kV power transformers at the 110/20 kV substation (RTP) Lenart, with the replacement of the second transformer planned for a later stage. As part of the refurbishment, all secondary systems, such as protection, control, metering, and power quality monitoring in the substation were replaced. To ensure effective mitigation of transient earth faults, a Petersen coil was installed for grounding the neutral point of the aforementioned transformers. At the request of the client and investor, all necessary Execution projects related to the secondary equipment were prepared for thirty 20 kV cubicle, two 110 kV overhead line feeder bays, two 110 kV transformer (TR) bays, and the remaining required systems such as the metering panel, station service equipment, the remote control and supervision system, the enclousure of measuring voltage miniature circuit breakers, and the design of resonant grounding of the medium-voltage (MV) neutral point of transformers TR 1 and TR 2. Within the scope of this document, the following drawings are presented in more detail: the drawnig of the 20 kV shunt cubicle, the drawing of the MV neutral grounding of TR 1 and TR 2, and the drawing of one of the 20 kV feeder cubicles, for which earth-fault protection variants are also presented in dependence of the neutral grounding operating regime. The preparation of the PZI documentation was followed by inspection and Factory Acceptance Testing (FAT) of the Petersen coil at the factory EGE spol. s r.o. in České Budějovice, where we were present during the execution of some of the tests, while others were carried out by EGE personnel and subsequently presented to us in the form of a report. After the installation of the coil and the remaining equipment in the substation, Site Acceptance Tests (SAT) were carried out to verify the correctness of the installation and the proper operation of the protection systems. After successful testing and a professional technical inspection, the Petersen coil, together with its control system, could be safely and reliably commissioned.

• Keywords: Petersen coil, Substation, Earth-fault protection, FAT, SAT