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Atthapol Ngaopitakkul - One of the best experts on this subject based on the ideXlab platform.
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Analysis of power quality issue in arc furnace Capacitor Bank system
2016Co-Authors: B. Sreewirote, Atthapol NgaopitakkulAbstract:In large furnace industry in Thailand, power factor has become a concerned issue due to electric utility department that charges extra money from factory causing low power factor. Many factories have been using Capacitor Bank to compensate reactive power, thus, increasing power factor in factory. With the Capacitor Bank, power quality in terms of harmonic current has become problem due to the switching transient that magnifies current harmonics and causes severe damage to Capacitor Bank and other nearby sensitive equipment. This paper aims to study power quality issue in terms of harmonics in steel furnace factory and its effect when switching Capacitor Bank into system. The study is done by using data from furnace plant in Phetchaburi province, Thailand as case study. The result reveals that after switching Capacitor Bank, harmonics have been significantly increased, thus, protection scheme must be implemented to ensure safety and reliability of the plant.
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Analysis of Transient Signals in a Substation Capacitor Bank System Using an Experimental Setup
International Review of Electrical Engineering-iree, 2016Co-Authors: Theerasak Patcharoen, Atthapol NgaopitakkulAbstract:The Capacitor Bank system is one of the important systems in an electric utility, with the benefit of power factor correction and reactive power compensation for transmission and distribution systems. Installation of a Capacitor Bank system in a substation causes transient signals when switching occurs. The aim of this research is to study the transient signals that occur when the Capacitor Bank is switched in each step. A Capacitor Bank-switching experimental test unit has been built to create a downscale Capacitor Bank system in a distribution–level substation. This unit was modelled after the NongChok substation under the Electricity Generating Authority of Thailand (EGAT). The impact on the distribution system when the Capacitor Bank is switched has been studied, and phenomena such as inrush currents, voltage transience, and frequency oscillation are taken into consideration. A method to reduce transient issues has been discussed and implemented in the test unit to evaluate the performance impact of these methods on a switching Capacitor Bank system.
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The Application of a 6% Reactor in High-Voltage Capacitor Bank Switching
International review of automatic control, 2016Co-Authors: Pathomthat Chiradeja, Atthapol NgaopitakkulAbstract:The switching of Capacitor Banks at high voltage for power-factor improvement and voltage support can generate significant transients. Such switching transients are produced by inrush currents and transient overvoltages in systems to which the Capacitor Bank is connected. These switching transients can cause damage to insulation and mal-operation of protective relays. This paper presents the simulation and investigation of a switching large-shunt Capacitor Bank in a 230kV Thailand substation system. A computer simulation using PSCAD/EMTDC was performed to determine the peak of the transient currents, the oscillation overvoltage and the frequency of the inrush current. The transient inrush current is generated by energizing of the 4×72 MVAr, 230 kV shunt Capacitor Banks. Methods of inrush current transient analysis and reduction were evaluated. Limiting the transients with a 6% reactor in series was simulated. The simulations indicate that the 6% reactor can significantly reduce the magnitude of the transients.
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characteristics and behavior of voltage transient and inrush current due to switching Capacitor Bank
International Conference on Intelligent Systems, 2014Co-Authors: Santipont Ananwattanaporn, Theerasak Patcharoen, Suntiti Yoomak, Atthapol Ngaopitakkul, Chaichan PothisarnAbstract:Capacitor Bank system in substation has been a topic of interest in these past few years because of its advantage on system. This paper presents a study on transient signal that occurs when switching Capacitor is integrated into the system. The method is based on building a Capacitor Bank switching experimental setup, which is downscaled from Electricity Generating Authority of Thailand (EGAT) at NongChok substation. This experimental setup is aimed to investigate transient signal in Capacitor Bank switching that has impact on the power system, such as inrush current and voltage transient. The result shows that switching transient causes an inrush current with high amplitude compared to nominal current. Moreover, an inductor installed in the system can limit inrush current; when inductor size is increased, inrush current will be decreased.
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Inrush current analysis for switching large shunt Capacitor Bank in a 230 kV substation system
2013 International Conference on Electrical Machines and Systems (ICEMS), 2013Co-Authors: Theerasak Patcharoen, Atthapol Ngaopitakkul, Chaichan PothisarnAbstract:This paper presents the simulation and investigation of switching large shunt Capacitor Bank in a 230kV Thailand substation system. Simulation is performed using PSCAD/EMTDC. The inrush current is generated by energizing of the 4×72 Mvar, 230 kV shunt Capacitor Banks. The purpose is to observe the inrush current to ensure safe and successful operations of the shunt Capacitor Banks. In addition, the effects of parameters such as sizing of current limiting reactor (CLR), pre-insert resistor (PIR) and 6% detuning reactor are investigated. The results of simulations are shown that the 6% detuning reactor can reduce inrush current more than other methods.
R Khayam - One of the best experts on this subject based on the ideXlab platform.
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solid state Capacitor switching transient limiter based on kalman filter algorithm for mitigation of Capacitor Bank switching transients
Renewable & Sustainable Energy Reviews, 2018Co-Authors: Teymoor Ghanbari, Farshid Naseri, Hadi Givi, Nima Tashakor, Ebrahim Farjah, R KhayamAbstract:Abstract Capacitor Banks are often utilized in conversion technologies of renewable energies for different reasons such as DC-link voltage regulation of power converters and power factor correction. During the Capacitor Bank energization process, voltage and current transients have negative impacts on the Capacitor Bank as well as the power quality of the system. In recent years, solid-state transient limiters have been proposed to rectify the problems relevant to Capacitor Bank switching. This paper presents a complete review of the recently proposed solid-state Capacitor Switching Transient Limiters (CSTLs). The objective of this review is to summarize and compare different methods for restraining the Capacitor switching transients in terms of suppression capability, efficiency, power quality, complexity, cost, etc. Subsequently, a novel high-performance solid-state CSTL is proposed. During the energization process, the proposed limiter suppresses the transient currents through a limiting resistor. A bidirectional static switch bypasses the limiting resistor at the steady-state. The bidirectional static switch is controlled via a simple hysteresis controller based on Kalman Filter (KF) algorithm. In order to clarify the working principles, the proposed limiter is analyzed in detail. The performance of the limiter is assessed using some simulations in MATLAB/SIMULINK. In order to demonstrate the feasibility of the proposed limiter, a prototype of the device has been fabricated in the laboratory. The results of the simulations and experiments confirm the capabilities as well as some superiorities of this limiter in comparison with other solid-state CSTLs.
Teymoor Ghanbari - One of the best experts on this subject based on the ideXlab platform.
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solid state Capacitor switching transient limiter based on kalman filter algorithm for mitigation of Capacitor Bank switching transients
Renewable & Sustainable Energy Reviews, 2018Co-Authors: Teymoor Ghanbari, Farshid Naseri, Hadi Givi, Nima Tashakor, Ebrahim Farjah, R KhayamAbstract:Abstract Capacitor Banks are often utilized in conversion technologies of renewable energies for different reasons such as DC-link voltage regulation of power converters and power factor correction. During the Capacitor Bank energization process, voltage and current transients have negative impacts on the Capacitor Bank as well as the power quality of the system. In recent years, solid-state transient limiters have been proposed to rectify the problems relevant to Capacitor Bank switching. This paper presents a complete review of the recently proposed solid-state Capacitor Switching Transient Limiters (CSTLs). The objective of this review is to summarize and compare different methods for restraining the Capacitor switching transients in terms of suppression capability, efficiency, power quality, complexity, cost, etc. Subsequently, a novel high-performance solid-state CSTL is proposed. During the energization process, the proposed limiter suppresses the transient currents through a limiting resistor. A bidirectional static switch bypasses the limiting resistor at the steady-state. The bidirectional static switch is controlled via a simple hysteresis controller based on Kalman Filter (KF) algorithm. In order to clarify the working principles, the proposed limiter is analyzed in detail. The performance of the limiter is assessed using some simulations in MATLAB/SIMULINK. In order to demonstrate the feasibility of the proposed limiter, a prototype of the device has been fabricated in the laboratory. The results of the simulations and experiments confirm the capabilities as well as some superiorities of this limiter in comparison with other solid-state CSTLs.
Hans Schellekens - One of the best experts on this subject based on the ideXlab platform.
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Capacitor Bank switching with vacuum circuit breakers
2008 China International Conference on Electricity Distribution, 2008Co-Authors: Hans SchellekensAbstract:After interruption of a capacitive current sometimes Non Sustained Disruptive Discharges (NSDDs) are observed when using vacuum circuit breakers. According to network calculations, NSDDs generate significant over-voltage on the terminal of the Capacitor Bank to ground and across the circuit breaker (CB) terminals. In a full scale experiment at 12 kV on an 8 Mvar Capacitor Bank artificial NSDDs are produced using a Triggered Vacuum Gap. The over-voltage depends on the momentary voltage difference across the breaker and, hence, varies with the phase angle. The over-voltage on the terminal of the Capacitor Bank to ground varies from 1.5 to 4.2 pu, and to maximum 5.2 pu. across the CB terminals. The effectiveness of surge arrestors on the limitation of the over-voltages is measured. The over-voltages are limited to 2.2 pu. on the terminals of the Capacitor Bank to ground and 3.2 pu. across the CB terminals. A single surge arrestor on the neutral point of the Capacitor Bank yields the same level of protection and, therefore, is a cost effective alternative. An application guide for switchgear and arrestors is presented.
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Capacitor Bank switching with vacuum circuit breakers
2008 23rd International Symposium on Discharges and Electrical Insulation in Vacuum, 2008Co-Authors: Hans SchellekensAbstract:After interruption of a capacitive current sometimes Non Sustained Disruptive Discharges (NSDDpsilas) are observed when using vacuum circuit breakers. According to network calculations, NSDDpsilas generate significant over-voltage on the terminal of the Capacitor Bank to earth and across the circuit breaker (CB) terminals. In a full scale experiment at 12 kV on an 8 MVAr Capacitor Bank artificial NSDDpsilas are produced using a TVG. The over-voltage depends on the momentary voltage difference across the breaker and, hence, varies with the phase angle. The over-voltage on the terminal of the Capacitor Bank to earth varies from 1.5 to 4.2 pu, and to maximum 5.2 pu. across the CB terminals. The effectiveness of surge arresters on the limitation of the over-voltages is measured. The over-voltages are limited to 2.2 pu. on the terminals of the Capacitor Bank to earth and 3.2 pu. across the CB terminals. A single surge arrester on the neutral point of the Capacitor Bank yields the same level of protection and, therefore, is a cost effective alternative.
P Jintagosonwit - One of the best experts on this subject based on the ideXlab platform.
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implementation and performance of an anti resonance hybrid delta connected Capacitor Bank for power factor correction
IEEE Transactions on Power Electronics, 2007Co-Authors: P Jintakosonwit, S Srianthumrong, P JintagosonwitAbstract:This paper presents a new three-phase anti-resonance hybrid delta-connected Capacitor Bank for power factor correction in low-voltage industrial power systems. In general, shunt Capacitors connected in series with reactors should be designed carefully before installation in order to avoid series and/or parallel harmonic resonance between the Capacitors and system inductances. However, the system parameters vary dynamically according to the power system configurations and loads. Consequently, harmonic resonance might occur after the Capacitors have been installed. The main objective of the proposed hybrid Capacitor Bank is to compensate for reactive power without any harmonic resonance. The hybrid Capacitor Bank is a combination of delta-connected Capacitors connecting in series with three small-rating single-phase inverters without any matching transformer. The inverter is used to improve the characteristics of the Capacitors. This paper deals with the implementation and control of the hybrid Capacitor Bank. Experimental results verify the viability and the effectiveness of the proposed anti-resonance hybrid delta-connected Capacitor Bank for reactive power compensation.