Ferroresonance Study on the VT in the Karoon 4 Power Plant 400 kV GIS Substation

Seyed Mohammad Hassan Hosseini,Yasertoghaniholari Yasertoghaniholari

doi:10.19026/rjaset.7.455

Seyed Mohammad Hassan Hosseini, Yasertoghaniholari Yasertoghaniholari

Open Access

https://doi.org/10.19026/rjaset.7.455

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Abstract

The main subject of the essay is study of ferroresonance in the voltage transformers at 400 kV GIS substation. Ferroresonance has destructive effects such as, undulations of high voltages, warming of transformers, increasing of heat, temperature increasing and damaging voltage transformers, high noise due to evolution due to magnet and bad working of protective instruments. So we have to apply limitations on system parameters to avoid such an undesirable phenomenon like this. In this study ferroresonance phenomenon on VTs of real GIS substation (karon 4 power plant had been studied. With regarding high risk of ferroresonance due to studied substation conditions, damping circuit (FDSD, ZD) had been designed with help of EMTP-RV and the results are presented in two conditions of being without damping and by using of damping in the circuit. The results show damping circuit is successful in obviation of these dangerous oscillations.

Highlights

Regarding to the advantages of GIS substations in comparison with AIS (Air Insulated Substation) and purposing that instruments such as current and voltage transformer, bypass disconnect or switch, high voltage conductor, grounding switchgear, breaker and etc., that are kept in boxes under pressure of SF6 gas and increasing usage of these substations toward the past and regarding to this point that urban and industries areas with increasing load and insufficient area and needing high voltages are regarded, in last year's the use of GIS substation have increased (Tseng and Cheng, 2011)
In this paper we study the Karoon 4 power plant GIS substation that is a 400 kV substation with double bus bar and disconnect or switch, this substation is fed by 4 single phase 100 MW transformers
Karoon 4 case study: The purpose of this paper is to study the ferroresonance on Voltage Transformers (VT) in Karoon 4 power plant GIS 400 kv substation as an example of GIS substation with bus bar and long line that have been effected by this phenomenon by to avoid occurrence of undesirable phenomena like increasing the voltage and damaging isolation and heating, destruction and damaging of VT

Summary

INTRODUCTION

Regarding to the advantages of GIS substations in comparison with AIS (Air Insulated Substation) and purposing that instruments such as current and voltage transformer, bypass disconnect or switch, high voltage conductor, grounding switchgear, breaker and etc., that are kept in boxes under pressure of SF6 gas and increasing usage of these substations toward the past and regarding to this point that urban and industries areas with increasing load and insufficient area and needing high voltages are regarded, in last year's the use of GIS substation have increased (Tseng and Cheng, 2011). In this paper we study the Karoon 4 power plant GIS substation that is a 400 kV substation with double bus bar and disconnect or switch, this substation is fed by 4 single phase 100 MW transformers. The outputs of these transformers are connected to the 400 kV network with 4 air lines. Ferroresonance has other destructive effects such as oscillation of high voltages, intricacy in wave forms of voltage and current, warming of transformers, damaging Voltage Transformers (VT), for example in Karoon 4 power plant 400 kV GIS substation, loud noise due of evolution due to magnet, malfunction protective instruments. All of the studies have been simulated by EMTP-RV software

PARALLEL CAPACITOR IN HV CIRCUIT BREAKER

CONCLUSION