New Concept for VFTO Attenuation in GIS with Modified Disconnector Contact System

Szewczyk, Marcin; Piasecki, Wojciech; Wroński, M.; Kutorasiński, K.

doi:10.1109/tpwrd.2014.2377094

Cited by 22 publications

(7 citation statements)

References 11 publications

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“…This method has been recently reported in [28] as investigated with the multi-spark VFTO modeling approach presented herein. The initial voltage conditions of the travelling waves originating from voltage flashovers in the disconnector contact system can also be controlled by modifying the disconnector contact system design, as reported in [35].…”

Section: Vfto Damping For Uhv Gis Developmentmentioning

confidence: 99%

Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgear and of conducting insulation co-ordination studies

Szewczyk¹

2017

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. Very fast transient overvoltages (VFTO) originate from steep voltage breakdowns in SF 6 gas that are inherent to operation of any switching device of the gas-insulated switchgear (GIS) type. For power stations with voltage ratings exceeding 500 kV, the ratio between equipment rated-and withstand-voltage levels becomes relatively low, which causes the VFTO peak values to reach the component's insulation withstand-voltage levels, thus becoming a design factor for high-and ultra-high voltage GIS. While well-established approach to VFTO analyses involves only single VFTO events (the so-called single-spark approach), there is often the need to analyze the entire VFTO generation process, for which the multi-spark approach to VFTO modeling is to be employed. The multi-spark approach allows one to evaluate the VFTO impact on the GIS disconnector design along with the impact of the VFTO on selection and dimensioning of the VFTO damping solutions. As the multi-spark approach to VFTO modeling is now being increasingly used in UHV GIS developments as well as for the insulation co-ordination studies of power stations, the present paper is motivated by the need to report on the VFTO multi-spark modeling approach and to lay a common ground for development works that are supported extensively with VFTO simulations. The paper presents physical assumptions and modeling concepts that are in use in such modeling works. Development of the multi-spark GIS disconnector model for VFTO simulations is presented, followed by an overview of examples of the model application for the GIS development works and for insulation co-ordination studies.Key words: very fast transient overvoltages (VFTO), gas-insulated switchgear (GIS), disconnector switch (DS), modeling, simulations, transients, switching, mitigation, breakdown voltage (BDV) characteristics. Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgearand of conducting insulation co-ordination studies To explore the VFTO associated with the operation of the UHV GIS disconnectors, the State Grid Corporation of China (SGCC) has recently established two full-scale test set-ups at the 1100 kV station in Wuhan (China), and conducted measuring campaigns with the total number of disconnector operations of approximately 2000 [8]. Several papers have been published based on this work, addressing different aspects of VFTO measurements and simulations. As an example, in [9] the impact of the disconnectors moving contact speed on the variety of VFTO parameters is analyzed.Also in the previous works conducted by ABB, the VFTO have been investigated to support design work of the 1100 kV disconnector [10,11] and to analyze the impact of the VFTO on selection of the VFTO damping solutions [6]. These works utilized the so-called multi-spark approach [4,12] for modeling the entire process of disconnector operation and to analyze distributions of the VFTO, along with other parameters, such as trapped charge voltage distributions, ...

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Section: Vfto Damping For Uhv Gis Developmentmentioning

confidence: 99%

Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgear and of conducting insulation co-ordination studies

Szewczyk¹

2017

Bulletin of the Polish Academy of Sciences Technical Sciences

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“…In addition to the well-established methods, the new methods on VFTO damping are constantly emerging, giving an attempt to well understand and select the most appropriate solution (or a combination) for particular GIS application. The new methods include high frequency resonators [16], GIS busbar with inductive arrangement and surge arresters [13], and disconnector with modified contact system [17].…”

Section: A Very Fast Transient Overvoltages In Gismentioning

confidence: 99%

High-Frequency Model of Magnetic Rings for Simulation of VFTO Damping in Gas-Insulated Switchgear With Full-Scale Validation

Szewczyk

Pawłowski

Kutorasiński

et al. 2015

IEEE Trans. Power Delivery

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Nanocrystalline magnetic rings have been experimentally proven for effective damping of Very Fast Transient Overvoltages (VFTO) in Gas-Insulated Switchgear (GIS). Application of any damping solution in specific GIS set-up (rated voltage, GIS arrangement) requires simulation-based design, which in turn requires reliable models with proven accuracy in demanding high frequency and high current VFTO conditions. This paper presents a new model of a magnetic ring, employing full frequency-dependent characteristics of the ring's complex impedance, as well as the dedicated approach on modeling of the saturation effect of the material magnetization characteristics. The saturation effect is modeled by a bypassing branch, activated at certain saturation current value calculated according to the specific magnetic material properties and for the VFTO main frequency component. The model was implemented in EMTP-ATP simulation software and validated experimentally in a full scale 550 kV GIS test set-up. The validation proved applicability of the model for the assessment of VFTO damping effectiveness with the use of nanocrystalline magnetic rings, and thus for design of particular magnetic based damping solution in a specific GIS setting.

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“…Therefore, traditional designing methodologies (used still in many factories) are replaced gradually by computer simulations that are more precise and efficient. Such a situation concerns also designing process of compact gas insulated switchgears (GIS) [6][7][8][9][10][11][12][13][14][15][16]. Computer simulations shorten the GIS designing process and bring down the costs involved in the building of prototypes and their laboratory tests.…”

Section: Introductionmentioning

confidence: 99%

Some aspects of medium voltage switchgear designing with aid of numerical analysis

Krajewski

Krasuski

Błażejczyk

2020

IET Science, Measurement & Technology

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New Concept for VFTO Attenuation in GIS with Modified Disconnector Contact System

Cited by 22 publications

References 11 publications

Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgear and of conducting insulation co-ordination studies

Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgear and of conducting insulation co-ordination studies

High-Frequency Model of Magnetic Rings for Simulation of VFTO Damping in Gas-Insulated Switchgear With Full-Scale Validation

Some aspects of medium voltage switchgear designing with aid of numerical analysis

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