Performance Of Surge Arresters Research Articles

A Surge Absorber for the Sri Lankan Distribution Substation to Mitigate Lightning Damage

Due to high grounding resistance and soil conditions surge arrester performance decreases. Even though in installation the standard earthing resistance is achieved with time the earthing resistance would be at a high value. When a high voltage arrives at the surge arrestor it discharges the excess voltage by providing low impedance shunt path to ground and providing protection for the transformer. Because of high impedance path the voltage would not divert to the ground and carry on its original path and damage the transformer. Therefore, for areas with high earthing resistances protection must be improved for distribution substations. Throughout this research method of reducing the peak and the rate of rise of surge was analyzed for providing extra protection for the transformer. The selected substation was AV047 it was selected because of lightning occurrence in the selected area, Replacement of the transformer due to damages cause by overvoltage surges and high earthing resistance of the installed substation. Usage of the surge absorber for additional protection was investigated throughout the research. By this method proposed by the research group it was able to provide the sufficient protection for the transformer during surge conditions and reduce the peak and the rate of rise of the surge. Losses of the surge absorber were also analyzed at different conditions. Further an algorithm was developed so that the surge absorber could be implemented to any MV and HV networks for protection of the transformer.

Assessing the impact of long-term operation, pollution and housing damage on the medium voltage surge arresters using non-destructive diagnostic techniques

Surge arresters installed in substations and overhead lines play a fundamental role in limiting atmospheric and switching overvoltages. In principle, surge arresters help to protect devices against fatal damage by choosing the specified protection level below the equipment withstand voltage. The reliability of surge arresters is still an important topic in many studies. Pollution and damage affect the performance of surge arresters and significantly impact their lifespan. It is necessary to analyze pollution problems and the effect of internal or external damage of surge arresters to find out the possibility of failure. The paper focused on an extensive study of medium voltage surge arresters from different manufacturers in various operation time, surface contamination, and damage types. In this study, we investigated new, used, damaged, and polluted metal-oxide medium voltage surge arresters to determine how these problems affect the performance of the surge arrester and whether the selected parameters exceed the standardized values defined in the standards. Research deals with the volt–ampere characteristic, Fourier analysis, reference voltage, and active losses to analyze the surge arrester’s performance.

Full-Scale Testing on Seismic Performance of Surge Arrester with Retrofitted Composite Insulators

In electrical substations, glass-fibre reinforced polymer (GFRP) insulators provide an alternative to porcelain insulators for better seismic performance. The bonded connection between the composite tube and the metal end fitting is a weak link under earthquake actions, and the failure risk of ultra-high voltage (UHV) substation equipment with GFRP composite insulators can be considerable in places with high seismicity. This study solved the problem by retrofitting and experimentally qualifying the seismic performance of surge arresters made of composite insulators. To ensure safety under a bending moment corresponding to the seismic demand, the bonded sleeve joint between the tube and end fitting was retrofitted by shear stiffeners and higher strength end fitting. A full-scale shaking table test was carried out to verify the performance of the retrofitted surge arrester, and the seismic responses to increasing earthquake actions were analyzed. The specimens in this study were full-scale, had the largest dimensions among substation equipment of the same type, and were subjected to an extremely high earthquake action of 0.5 g; therefore, the seismic testing results produced in this study can serve as an important reference for the industry.

Mitigation of common mode failures at multi-circuit line configurations by application of line arresters against back-flashovers

Due to the limited number of corridors multi circuit line configurations are often applied. These overhead lines frequently consist of high towers that are subject to lightning strokes. In case of higher current amplitudes and higher footing resistances due to bad earthing conditions back-flashovers are caused leading to common mode failures and to severe outages. The paper describes investigations performed by means of computer simulations to identify the towers of a multi-circuit line consisting of voltage levels 380 kV, 220 kV and 110 kV that are endangered by back-flashovers of the 110-kV double-circuit lines. The footing resistance of towers of the targeted line section has been measured by an instrument at high-frequency. Influence of various factors on the back-flashover over 110 kV insulator strings has been studied by means of EMTP-ATP simulations. Different current waveforms of the lightning stroke have been used to represent the first stroke and subsequent strokes. The towers are represented by the models described in [3], [8]. Available flashover analysis methods [7], [8], [12], [13] like leader development method by Pigini et al and by Motoyama, and voltage-time integration method by Kind have been applied. The towers at which back-flashover is more likely to occur than at other towers are identified by the time integral of voltage according to Kind. Various factors like tower footing impedance, tower surge impedance and tower height are considered. Application of line a surge arrester is shown to be a successful mitigation technique to reduce the back-flashover rate of those 110 kV lines. The lightning overvoltage performance of surge arresters has been analyzed by means of digital simulations. Based on the results of investigations line arresters were installed on the towers in question. Since the installation no further common mode failure has been observed.

Surge analysis for lightning strike on overhead lines of wind farm

The overhead line in wind farm is vulnerable to lightning strikes at a high risk. The lightning surge would propagate along the line and damage the equipment in substation. In this work, the mathematical models for transmission tower, overhead lines, power transformer and wind farm substation have been developed in the environment of EMTP, especially the wind turbine converter and step up transformer models. The transients in the case of back flashover and shielding failure are analysed. The influences of radial and cross-shaped connections of wind turbine topology on the wave reflection and refraction have been investigated. The performance of surge arrester, not only the protection area but also the absorbed energy under lightning overvoltage is also computed. The wind farm substation is divided into multi zones and the transient response at different nodes is obtained. It indicates that the characteristics and propagation for surge under lightning strike on overhead line are completely different from direct lightning strike on wind turbine receptor. The capacitance between the high and low voltage side of step up transformer plays a key role in system transients. Compared with back flashover, the overvoltage caused by shielding failure is relatively small; the cross-shaped scheme is preferred and would benefit the lightning protection; the absorbed energy of arresters under a high lightning current is a major consideration.

Enhancing the Protective Performance of Surge Arresters against Indirect Lightning Strikes via an Inductor-Based Filter

Preventing the medium voltage (MV) transformer fault by protecting transformers against indirect lightning strikes plays a crucial role in enhancing the continuous service to electricity consumers. Surge arresters, if selected properly, are efficient devices in providing adequate protection for MV transformers against transient overvoltage impulses while preventing unwanted service interruptions. However, compared to other protective devices such as the spark gap, their prices are relatively high. The higher the surge arrester rating and energy absorption capacity are, the higher the prices go. This paper proposes an inductor-based filter to limit the energy pushed into the surge arrester, and consequently to prevent any unwanted failure. An energy-controlled switch is proposed to simulate the fault of the surge arrester. Surge arresters with different ratings, e.g., 12 kV, 18 kV, 24 kV, 30 kV, 36 kV, and 42 kV with two different classes of energy, namely, type a and type b, are tested under different indirect lightning impulses such as 100 kV, 125 kV, 150 kV, 175 kV, 200 kV, 250 kV, 300 kV, and 500 kV. Furthermore, these surge arresters are equipped with different filter sizes of 100 μH, 250 μH, 500 μH, and 1 mH. Results prove that equipping a surge arrester with a proper filter size enhances the performance of the surge arrester significantly such that a high rating and somewhat expensive surge arrester can be replaced by a low rating and cheap surge arrester while providing similar or even better protective performance for MV transformers. Therefore, such configurations not only enhance the protective capability of surge arrester, but also reduce the planning and operating costs of MV networks.

A new approach to electrical modeling of surge arrester considering temperature effect on V-I characteristic

The V-I characteristic of ZnO varistor which has been obtained from experimental test, is an important parameter to model surge arrester electrical behavior. Generally, in grid voltage, this characteristic depends on temperature variations. In this paper, an improved metal oxide surge arrester electrical model has been proposed under grid voltage. Temperature effects on surge arrester performance have been considered in the proposed model. Artificial neural network has been used to determine V-I characteristic at temperature variations. Therefore, in proposed model, the V-I characteristic of each varistor has been estimated based on applied voltage and operating temperature. To validate proposed model, laboratory setup and infrared thermal camera have been arranged and experimental tests results have been compared with simulation ones. Results revealed that there has been a good agreement between simulation and experimental results. Moreover, electrical behavior of surge arrester is predictable with high precision through the proposed artificial model.

Mitigation of lightning overvoltage in gas insulated substations concerning ferromagnetic ring effect

Summary In this paper, the impact of surge arresters and ferromagnetic ring on the magnitude as well as the steepness of lightning overvoltages in gas insulated substation (GIS) are investigated. This investigation is carried out through modeling of a typical 380-kV GIS using ATP/EMTP for very fast transient overvoltages. Two scenarios of lightning strikes, backflashover and shielding failure are considered. Also, the impact of ferromagnetic ring on the surge arrester performance is evaluated. The evaluation is carried out considering surge arresters located at entrance, and at transformer terminals of GIS. Finally, the effect of ferromagnetic ring parameters on the arresters performance is evaluated and discussed. The obtained results show that the presence of ferromagnetic ring can affect the rating selection of GIS surge arresters. Copyright © 2016 John Wiley & Sons, Ltd.

Heat transfer analysis of metal oxide surge arrester under power frequency applied voltage

Electro-thermal model of metal oxide surge arrester based on adaptive method has been proposed in this paper. Finite element method has been used to model surge arrester. Power loss, which is major parameter in electro-thermal analysis, has been estimated as a heat source in proposed model using artificial neural network and adaptive network based fuzzy inference system. In addition to voltage and temperature, operating history is also an important factor that must be considered in power loss estimation process. In order to formulize surge arrester performance history, degradation factor has been suggested as a new index in this paper. Therefore, voltage, temperature and degradation factor have been used as inputs in artificial models. So as to train the artificial neural network and adaptive network based fuzzy inference system, experimental results have been obtained by laboratory tests on new and utilized surge arresters varistors. In this regards, high voltage experimental setup, chamber and an oven have been prepared to acquire modeling data. Also, the results of infrared thermal camera have been used to validate the results of proposed adaptive electro-thermal model. Moreover, convection and radiation as effective factors in surface to ambient heat transfer have been studied and compared.

폴리머 피뢰기의 구조에 따른 온도와 누설전류 특성

In this paper, the ZnO surge arrester performance of power distribution class has been studied under different manufacturing conditions such as housing materials(polymeric, porcelain), interface sealants and one-body molding type. In the recent years, the polymeric ZnO surge arresters have been developed and put into operations based on their excellent characteristics. For polymeric surge arresters, the inner gas volume is extremely small, especially in solid insulation polymeric arresters there are not any gas volume inside arresters in the structure due to polymeric materials are filled into the internal gas volume. The sealing integrity is related to safe operation of surge arrester, the prime failure reason of porcelain housed arresters is moisture ingress. In this paper, the sealing integrity of polymeric surge arresters is investigated with moisture multi-aging test and ingress test. The evaluation techniques are used to inspect the sealing integrity of polymeric arresters, including leakage current, surface temperature, reference voltage and dissipation factor.

Surge Arrester Performance Under AC Artificial Pollution and Impulse Conditions: A Comparative Investigation

This article presents a comparative experimental investigation of surge arrester (SA) performance under clean, unpolluted and polluted conditions. Three different surge arresters rated 33 kV and 10 kA were tested to investigate how the internal active material (either zinc oxide/metal oxide, ZnO, or silicone carbide, SiC) and the arrester housing material affect the overall performance under clean and pollution conditions. Both AC and impulse tests were conducted on SiC porcelain-, ZnO polymeric-, and ZnO silicone-rubber- (composite insulator) housed arresters. In the case of AC application, both the internal and the external currents were measured, while the discharge current is measured under impulse voltage application.

Parameter Determination for Modeling Systems Transients—Part V: Surge Arresters IEEE PES Task Force on Data for Modeling System Transients of IEEE PES Working Group on Modeling and Analysis of System Transients Using Digital Simulation (General Systems Subcommittee)

The performance of surge arresters during electromagnetic transients on power systems can be simulated with Electromagnetic Transient Program (EMTP) type computer programs. This paper discusses the steps to be performed for deriving the parameters needed to represent gapless metal-oxide surge arresters in transient simulations. The paper includes a summary of the mathematical representation, guidelines for choosing appropriate parameters, and the conversion procedures used to obtain parameters.

Comparison of different test methods to assess the thermal stresses of metal oxide surge arresters under pollution conditions

Laboratory tests investigating the thermal performance of surge arresters under contamination and wetting environmental conditions that lead to nonuniform voltage stresses along the arresters are reported. The validity and repeatability of various laboratory test procedures are examined. The results are analyzed by means of a mathematical and a physical model. >