The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform
Chandra Sekhar Patsa - One of the best experts on this subject based on the ideXlab platform.
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Estimation of Switching Surge flashover rate of 1200-kV UHVAC transmission line considering Switching overvoltage waveshape
Electrical Engineering, 2020Co-Authors: Ramchandra Reddy Annadi, Chandra Sekhar PatsaAbstract:The insulation of the power transmission system experiences stresses due to power–frequency voltage under normal operating conditions, temporary overvoltages at or near power–frequency and transient overvoltages arising either from Switching operations and faults or from lightning discharges. However, in the insulation design of extra-high-voltage and ultra-high-voltage systems, transient overvoltages arising from Switching operations and faults become the controlling factor. Insulation failure probability under Switching overvoltages is the main impressive concern in the estimation of Switching Surge flashover rate. In this paper, a practical method is used to estimate the Switching Surge flashover rate of insulation under Switching overvoltages generated during energization, re-energization, fault initiation and fault clearing of an unloaded transmission line, which considers the variable characteristics of the insulation strength of the transmission line according to the Switching overvoltage waveshape. The results focus on the comparison between traditional and practical methods which considers the effect of the front time on the first 1200-kV UHVAC transmission line in India.
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Estimation of Switching Surge Flashover Rate of a 1200 kV UHVAC Transmission Line due to Switching Overvoltages
INAE Letters, 2018Co-Authors: Ramchandra Reddy Annadi, Chandra Sekhar PatsaAbstract:The rapid increase in transmission voltages to fulfil higher demand of the transmitted power yields to put the Switching Surges as the governing factor in the insulation design process for EHV and UHV systems. Contemporary methods of insulation coordination utilise probabilistic approach and statistical methods particularly in the case of ultra-high voltage systems. This paper determines the statistical distributions of energization, re-energization, fault initiation and fault clearing overvoltages of the 1200 kV system modelled in PSCAD. Decisive figures like mean value, standard deviation and 2% statistical overvoltage values of Switching overvoltage are estimated using randomness of the instants of closing with 526 operations for line energization and re-energization, and randomness of faulted phase, fault location and fault times with 3 faulted phases, 8 fault locations and 21 fault timings, 504 simulations for fault initiation and fault clearing. Ascertaining the investigations from the above simulations the stress on the towers is estimated. From the stress and insulation strength of the tower a systematic approach to calculate the Switching Surge flashover rate (SSFOR) is presented.
Ramchandra Reddy Annadi - One of the best experts on this subject based on the ideXlab platform.
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Estimation of Switching Surge flashover rate of 1200-kV UHVAC transmission line considering Switching overvoltage waveshape
Electrical Engineering, 2020Co-Authors: Ramchandra Reddy Annadi, Chandra Sekhar PatsaAbstract:The insulation of the power transmission system experiences stresses due to power–frequency voltage under normal operating conditions, temporary overvoltages at or near power–frequency and transient overvoltages arising either from Switching operations and faults or from lightning discharges. However, in the insulation design of extra-high-voltage and ultra-high-voltage systems, transient overvoltages arising from Switching operations and faults become the controlling factor. Insulation failure probability under Switching overvoltages is the main impressive concern in the estimation of Switching Surge flashover rate. In this paper, a practical method is used to estimate the Switching Surge flashover rate of insulation under Switching overvoltages generated during energization, re-energization, fault initiation and fault clearing of an unloaded transmission line, which considers the variable characteristics of the insulation strength of the transmission line according to the Switching overvoltage waveshape. The results focus on the comparison between traditional and practical methods which considers the effect of the front time on the first 1200-kV UHVAC transmission line in India.
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Estimation of Switching Surge Flashover Rate of a 1200 kV UHVAC Transmission Line due to Switching Overvoltages
INAE Letters, 2018Co-Authors: Ramchandra Reddy Annadi, Chandra Sekhar PatsaAbstract:The rapid increase in transmission voltages to fulfil higher demand of the transmitted power yields to put the Switching Surges as the governing factor in the insulation design process for EHV and UHV systems. Contemporary methods of insulation coordination utilise probabilistic approach and statistical methods particularly in the case of ultra-high voltage systems. This paper determines the statistical distributions of energization, re-energization, fault initiation and fault clearing overvoltages of the 1200 kV system modelled in PSCAD. Decisive figures like mean value, standard deviation and 2% statistical overvoltage values of Switching overvoltage are estimated using randomness of the instants of closing with 526 operations for line energization and re-energization, and randomness of faulted phase, fault location and fault times with 3 faulted phases, 8 fault locations and 21 fault timings, 504 simulations for fault initiation and fault clearing. Ascertaining the investigations from the above simulations the stress on the towers is estimated. From the stress and insulation strength of the tower a systematic approach to calculate the Switching Surge flashover rate (SSFOR) is presented.
Urmil Parikh - One of the best experts on this subject based on the ideXlab platform.
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controlled Switching technique for minimization of Switching Surge during energization of uncompensated and shunt compensated transmission lines for circuit breakers having pre insertion resistors
International Journal of Electrical Power & Energy Systems, 2018Co-Authors: Kunal A Bhatt, Bhavesh R Bhalja, Urmil ParikhAbstract:Abstract Controlled Switching Device (CSD) is considered to be the replacement of Pre-Insertion Resistor (PIR). Moreover, tie Circuit Breaker (CB) used in One-and-a-Half-Breaker (OHB) scheme as well as in line connected with non-switchable reactor scheme are employed with PIR and CSD. In this paper, a new methodology has been proposed using CSD with PIR-CB for further mitigation of the Switching Surge during energization/re-energization of Un-compensated Transmission Line (UCTL) and Shunt reactor compensated Transmission Line (SCTL). Unlike the existing methodology (both for UCTL/SCTL) which requires line side voltage signatures, the proposed methodology does not necessitate the same for SCTL and requires only the polarity of line side voltages for UCTL. The performance of the proposed methodology has been evaluated by generating diversified cases on 400 kV UCTL and SCTL using PSCAD/EMTDC software package. The proposed Switching strategy is able to mitigate the Switching Surge of the order of 33% for UCTL and 20% for SCTL. Comparative evaluation of the proposed methodology with usual PIR methodology clearly shows its effectiveness with reference to statistical variations of CB. The proposed methodology has been validated during effects of various parameters such as weather conditions, insulation resistance, change in closing phase sequence, and Surge Arrestor (SA).
D. Thukaram - One of the best experts on this subject based on the ideXlab platform.
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Control of Switching Surges due to energization of 765kV UHV transmission line
2012 IEEE 7th International Conference on Industrial and Information Systems (ICIIS), 2012Co-Authors: K. Ravishankar, D. ThukaramAbstract:Reduction of Switching Surge over voltages allows an economic design of UHV transmission system with reduced insulation. The various means of Switching Surge over voltage control with pre-insertion resistors/closing resistors, shunt reactors and controlled Switching are illustrated. The Switching Surge over voltages during the energization of series compensated line are compared with uncompensated line. An Electromagnetic transients program has been developed for studying the effect of various means of control of Switching transients during 765kV UHV transmission line energization. This paper presents the studies carried out on Switching Surges control in 765kV UHV transmission line energization.
Kunal A Bhatt - One of the best experts on this subject based on the ideXlab platform.
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controlled Switching technique for minimization of Switching Surge during energization of uncompensated and shunt compensated transmission lines for circuit breakers having pre insertion resistors
International Journal of Electrical Power & Energy Systems, 2018Co-Authors: Kunal A Bhatt, Bhavesh R Bhalja, Urmil ParikhAbstract:Abstract Controlled Switching Device (CSD) is considered to be the replacement of Pre-Insertion Resistor (PIR). Moreover, tie Circuit Breaker (CB) used in One-and-a-Half-Breaker (OHB) scheme as well as in line connected with non-switchable reactor scheme are employed with PIR and CSD. In this paper, a new methodology has been proposed using CSD with PIR-CB for further mitigation of the Switching Surge during energization/re-energization of Un-compensated Transmission Line (UCTL) and Shunt reactor compensated Transmission Line (SCTL). Unlike the existing methodology (both for UCTL/SCTL) which requires line side voltage signatures, the proposed methodology does not necessitate the same for SCTL and requires only the polarity of line side voltages for UCTL. The performance of the proposed methodology has been evaluated by generating diversified cases on 400 kV UCTL and SCTL using PSCAD/EMTDC software package. The proposed Switching strategy is able to mitigate the Switching Surge of the order of 33% for UCTL and 20% for SCTL. Comparative evaluation of the proposed methodology with usual PIR methodology clearly shows its effectiveness with reference to statistical variations of CB. The proposed methodology has been validated during effects of various parameters such as weather conditions, insulation resistance, change in closing phase sequence, and Surge Arrestor (SA).
