The simulation results show that contaminations have no effect of potential distribution on the insulator surface while electric field distributions. For suspension type of insulators, the ratio of voltage across the whole string to the product of number of discs and the voltage across the disc nearest to the conductor is known as string efficiency. Composite tension insulators advantages and features. Composite insulator for transmission and distribution lines 10kv composite insulator fig. Influence of voltage type and polarity on electric field distribution along a polymeric insulator under contaminated conditions arshad1, a. Let us know how the potential is distributed over each unit of suspension insulator whether is it uniform or nonuniform. Neural network estimator for electric field distribution on. Single insulator cap and conductor cover for distribution. Effects of disc insulator type and corona ring on electric.
Finite element method fem is adopted for this work. List any four errors in induction type energy meter. Figurea below shows a typical suspension insulator. Technical data of suspension insulator type 523 are reported in table 1. The porcelain portion of each disc is in between two metal links. The following points may be noted regarding the potential distribution over string of suspension insulators. Composite insulator for transmission and distribution lines. The effect of stray capacitance over voltage distribution using kcl at each node it can be found that. Pdf a set of models for investigation of voltage distribution along. Composite tension insulators are widely used on high voltage distribution and transmission lines and these composite insulators have many advantages and features.
Calculation of potential distribution is extensively performed in the design and development of highvoltage insulators. Voltage distribution over a suspension insulator string fig. It shall be noted that the number of discs in suspension insulator can be increased or decreased by adding extra discs or removing a disc. These capacitances could be made negligibly small by increasing the distance between the.
Also the effect of corona ring on potential distribution over insulator strings with. Porcelain string insulators are widely used in highvoltage transmission lines. Vph the phase voltage across the subsequent units measured from the ground respectively. What is difference between conductor and insulator. The effect of stray capacitance over voltage distribution stray capacitance causes unequal voltage distribution over the string. Voltage and electric field are the main factors to withstand the insulation. Sep 25, 2011 string effeciency and methods to improve string effeciency posted on september 25, 2011 by k10blogger the ratio of voltage across the whole string to the product of number of discs and the voltage across the disc nearest to the conductor is known as string efficiency i. The following points may be noted regarding the potential distribution over a string of suspension insulators. Measurement of voltage distribution on high voltage. The main cause of cracking is due to the stress produced in the porcelain due to unequal expansion and construction produced in cement, steel and porcelain caused by seasonal heat cold, dryness, and dampness or by heating of the insulator.
Calculation of voltage distribution along porcelain. The number of insulator discs each rated 11 kv required in. We talked about advantages and disadvantages of each type of insulators. Faulty insulators could appear in the hv transmission line insulator string under the comprehensive effect of electrical, mechanical and environmental factors and they can be detected according to the space potential and electric field distribution variation characteristics around the insulator string. Potential distribution over suspension insulator string eeeguide. Depending upon the working voltage, the desired number of discs can be connected in series. In the experiment, the sphere gap was used to measure the voltage along insulation string. Pdf investigating the effects of disc insulator type and corona. Therefore, each disc forms a capacitor c as shown in fig. The figure below shows a 3disc string of suspension insulator. This video contains the detailed information about power factor improvement.
Potential distribution over a string of suspension insulators. Evaluation of string efficiency and voltage distribution of. The computation of electric potential distribution across suspension insulator strings used for high voltage overhead transmission lines is very. We are establish in 1978, and produce insulators and relative until 500kv. Simulation of voltage distribution calculation methods over a. Low and high voltage distribution along a cap and pin. This is because of the capacitances formed between the metal parts of the insulators and tower structure.
Influence of voltage type and polarity on electric field. Solved calculation of string efficiency for suspension. Farzaneh2 1 school of engineering and built environment, glasgow caledonian university 2canada research chair on atmospheric icing engineering of power networks ingivre. Insulator,high voltage insulator,china insulatororient china. Simulation of potential and electric field due to defective. Potential and electric field distribution of 220kv insulator. In the previous article, we have discussed different types of insulators used in an overhead transmission line. For the present study, the type of suspension insulator type 523 is chosen. We focused on a solution that exceeds rus requirements for this class of product. Single insulator cap and conductor cover for distribution power lines our patented insulator caps and conductor covers have been designed with the recommendations from utility engineers, linemen, and wildlife biologists. In these topics, it is discussed the voltage distribution over suspension insulator string. The disc near the line conductor is extremely stressed and takes the maximum voltage in the absence of stress. Properties of porcelain suspension insulator for ultra high. The capacitance between the links and the earth is 0,2 c, where c is the capacitance of an insulator determine the potential distribution along the insulators strain.
A porcelin guy strain insulator is strong enough to hold the high tension of a guy under load because the two holes at right angles overlap each other so that the porcelain is under compression. Therefore it is very much essential for insulator string to relate the potential distribution. A string of suspension insulator consists of a number of porcelain discs connected in. Aug 24, 2011 ii each unit or disc of suspension type insulator is designed for low voltage, usually 11 kv. It is well known that under working ac voltage, the voltage distribution along a cap and pin insulator string is very uneven due to the presence of stray capacitances from the caps to the line conductor and especially to the earthed supporting tower. Insulation feature transmission line insulator condition. The electrical stress applied to a suspension insulator string is not uniform with the highest stress occurring close to the live conductor. Suspension insulator string is widely used as insulator structures in high voltage overhead. If a protective corona ring inserts capacitances from the line, with the link of the middle. A suspension insulator is basically a string of number of porcelain disc connected in series though metallic link. A suspension insulator strain consists of a series of alternately insulators and metal parts, which bind each insulator to the next. Potential distribution over a suspension insulator string the figure below shows a 3disc string of suspension insulator. Pdf the voltage distribution of insulator strings, which are very common in the.
String efficiency is used to determine the level of uniformity of voltage distribution of insulator string. String efficiency of suspension insulators and methods of improving. In operational high voltage, the nonuniformity of potential distribution across the insulator string is due to the presence of stray capacitance. In this study, the voltage distribution over an insulator string of suspension insulators and the string efficiency have been investigated with respect to the atmospheric conditions such as wind. Institute for theoretical physics events xwrcaldesc. String efficiency of suspension insulator electrical concepts. An overhead 3phase transmission line, which has phase voltage 30 kv, is hanging from a three insulators suspension strain. Via this software the electric field and potential distribution can be calculated very easily once the desirable geometry is accurately designed. In this article, we will be talking about voltage distribution and string efficiency of suspension insulator. This is a lecture video for diploma 3rd year students of electrical engineering. Potential distribution over suspension insulator string. First of all thanks for visiting electrical engineering info now let us discuss p otential distribution in a string of suspension insulators. Measurement and simulation of the voltage distribution and. In this project, calculate the voltage distribution along a string of 5 suspension insulators, and determine the efficiency of string and we get efficiency equal to.
Mar 16, 2017 evaluation of string efficiency and voltage distribution of 400 kv over a string of glass suspension type insulator in different atmospheric condition ijsrdvol. A suspension insulator string has three units with ground capacitance of 0. Orientcomposite tension insulators composite insulator. Mankinds benefit the proceedings of a space congress held november 1519, 197 1, at huntsville, alabama sponsored by the national aeronautics and space administration and the huntsville association of technical societies prepdred at. String efficiency of suspension insulators is an important consideration since it decides the potential distribution along the string. Effect of voltage type and polarity on electric field and potential distribution are investigated in this paper. We are also the qualified supplier of electrified railway insulato. Porcelain and glass insulators have been used for over a hundred years and although these ma terials have proven themselves resistant to environmental ageing, their pollution performance has often been relatively poor due to hydrophilic surfaces. Suspension insulators or string insulators are very widely used in electrical overhead transmission system.
Voltage distribution over suspension insulator string. The dimension of suspension insulator type 523 is used for the study as shown in fig. String efficiency of suspension insulator when the voltage is applied across the suspension insulator string, it is unequally distributed across the individual unit. The slurry was fabricated after ball milling were mixed raw materials. Abstract porcelain string insulators are widely used in highvoltage. In this paper, the voltage distribution and the electric field of a glass insulator has been measured and calculated using a program based on the finite elements method. Calculation of voltage distribution along porcelain suspension. Better than products of high tension insulator factory ranchi in addition, a large selection of fittings can be used. Voltage distribution over suspension insulator string efficiency.
This paper was the research of 400 kn suspension insulator for ultra high voltage that included alumina of 17 wt%. In case of the clean string insulator condition, the string efficiency which the insulator consists of 5, 6, 7 insulator string without guard ring equals 69. Due to the presence of shunt capacitor, the voltage. Due to the presence of shunt capacitor, the voltage across the suspension insulators does not distribute itself uniformly across the each disc.
Porcelain punctures occur in the region of maximum electrical stress between the metal cap and the. The measurement of the voltage distribution along high. An aep study of 1100 service aged porcelain disc insulators came to the following conclusions. This constitutes a series of connected capacitors, with each ones capacitance being created by two successive metal connectors clips with the porcelain as a dielectric. Neural network estimator for electric field distribution on high voltage insulators al abstract this paper introduces, a threedimensional 3d neural network electric fields estimator, which will be used to determine the electric field distribution on high voltage insulator surface. Simulation and measurement of the voltage distribution on. Therefore it is very much essential for insulator string to relate the potential distribution and electric field distribution to that of the respective ideal string accurately. However, there is a significant thing to be considered in case of these string insulators, known as string efficiency. Jul 23, 2017 in this article, we will be talking about voltage distribution and string efficiency of suspension insulator. String efficiency of suspension insulators and methods of.