Insulation risk assessment of controlled switching considering pre‐strike voltage and line trapped charge

Deyhim, Fakhrali; Ghanizdeh, Reza

doi:10.1049/iet-smt.2018.5150

Cited by 5 publications

(3 citation statements)

References 17 publications

(31 reference statements)

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“…Although the presence of shunt reactors has an important effect on switching overvoltages, no accurate method has so far been proposed to model the worst case switching in a line equipped with these devices. Indeed, the recorded field data have generally been considered as sufficient (see [13] and [14]) and the installation of shunt reactors has been ignored in some studies ( [15] and [16]).…”

Section: -Introductionmentioning

confidence: 99%

Frequency modeling of trapped charge source for transmission line switching studies in presence of shunt reactor using EMTP/ATPDraw

Akafi-Mobarakeh

Shariatinasab

Vahidi

2023

Preprint

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Insulation coordination studies are of great importance in power grid reliability. In this paper, a new method is proposed for modeling trapped charge sources (TCS) in switching transient studies. The TCS is used to take account of the voltage stored in line capacitors during reclosing operation after fault occurrence. The proposed model is designed based on the active filter concept, so it does not have the limitations of conventional TCS for simulating transient states in EMTP/ATPDraw. Given the natural frequencies of the transmission line to which the proposed TCS (PTCS) is connected, the PTCS injects the appropriate frequencies and eliminates voltage oscillations, which limit the use of TCS. To verify the efficiency of the PTCS, it is implemented in a real system with a shunt reactor, and the results are then compared with field measurements. A comparison of the results shows that the PTCS eliminates the voltage oscillations in the simulation before closing and provides a smooth voltage with the desired amplitude. Using the proposed model, the maximum line switching overvoltage is correctly calculated; this, in turn, results in a more accurate transmission line insulation design, which is technically and economically beneficial.

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Section: -Introductionmentioning

confidence: 99%

Frequency modeling of trapped charge source for transmission line switching studies in presence of shunt reactor using EMTP/ATPDraw

Akafi-Mobarakeh

Shariatinasab

Vahidi

2023

Preprint

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“…Haphazard switching of the three-pole CB of the transmission line causes over-voltages that their amplitudes might attain to 4 pu and reduces the lifespan of switching equipment. The most severe over-voltages are created by closing the CB of the transmission line with the remaining voltage [8][9][10]. The traditional method for decreasing the mentioned over-voltages is to apply a before-connecting resistor in the CB structure or a lightning arrester in the transmission line, which is costly and not efficient [11,12].…”

Section: Introductionmentioning

confidence: 99%

Synchronous switching of uncompensated transmission line, by considering the effect of coupling voltage between the phases, trapped charge and the characteristics of CB

Karimonnafs

2023

IET Science Measure & Tech

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The synchronous closing technology is an effective way to reduce transient current and voltage, prevent equipment failures, and improve power quality. The proposed algorithm, first by considering the coupling voltages between phases and the residual voltages in an uncompensated transmission line, calculates the zero instant of the voltage curves (ZVC instant) across the poles of the circuit breaker (CB) that is ideally the optimum instant to close the CB. Although other studies have utilized ZVC detection by solely considering either coupling or residual voltages. Secondly, the algorithm seeks to account for the mechanical scattering time of the CB and the rate of decrease of dielectric strength (RDDS) by incorporating delay times into the previously calculated delay values. Although other works have investigated the effect of RDDS or mechanical scattering operation time on synchronous switching to some extent, they have not fulfilled any optimization taking both of them into account.By exerting this algorithm, each phase of CB is closed in the ideal optimum closing target (ZVC instant) with a maximum error of one sample, and then, taking into account the CB characteristics, by compensating the RDDS and mechanical scattering time, CB is energized in the optimal time interval, where pre‐strike voltages are minimized.

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“…Surge arresters along the transmission line or a more complex switchsync relay are needed for long or compensated lines. Also, the controlled switching mechanism has been examined in (Deyhim and Ghanizdeh, 2019;Shafy et al, 2016) in tandem with the impact of the preinsertion resistor on energising a capacitor bank.…”

Section: Introductionmentioning

confidence: 99%

Overhead Line Swithcing Considering Circuit Breaker Standard Deviation Times

Băiceanu,

Nemeș,

Neagu

et al. 2022

Bulletin of the Polytechnic Institute of Iași. Electrical Engineering, Power Engineering, Electronics Section

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The switching of electrical equipment in normal operation conditions should be performed in optimal moments with regard to the variation of the voltage and current waveforms. Deviations from these ideal conditions will result in disruptive transient regimes, which, depending on their severity, can lead to equipment malfunctions or insulation damage. This paper continues a previous research study regarding the impact of the real switching moment regarding the known ideal conditions on various types of equipment. Previous efforts have concentrated on the study of the behavior of capacitor banks, power transformers and underground cable lines when switching is performed in different points on the voltage sine wave. This paper continues the research by studying high voltage overhead lines in the same conditions. The voltage and current waveforms are measured and analyzed for different switching times, using the EMTP software package. A comparison discussion with the previous results highlights the main findings.

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Insulation risk assessment of controlled switching considering pre‐strike voltage and line trapped charge

Cited by 5 publications

References 17 publications

Frequency modeling of trapped charge source for transmission line switching studies in presence of shunt reactor using EMTP/ATPDraw

Frequency modeling of trapped charge source for transmission line switching studies in presence of shunt reactor using EMTP/ATPDraw

Synchronous switching of uncompensated transmission line, by considering the effect of coupling voltage between the phases, trapped charge and the characteristics of CB

Overhead Line Swithcing Considering Circuit Breaker Standard Deviation Times

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