The following points may be noted regarding the potential distribution over a string of suspension insulators: Due to the presence of shunt capacitor, the voltage across the suspension insulators does not distribute itself uniformly across the each disc. It consists the number of porcelain insulator units connected with each other by metal links to form a flexible string.
Suspension Insulators in Overhead Transmission Lines Jinyong
Power frequency voltage of feed line is distributed along string elements in unequal amounts due to parasitic capacities (on ground and wire).
The porcelain portion of each disc is between two metal links.
These are generally used for ht. 701, which is rated at only 70,000 volts, while a string a suspension insulators could be assembled that stands off 1,000,000 volts or more. The modular design offers the ability for custom applications to adapt to any end user's unique environment. The suspension insulator separates the line conductors and supports them electrically.
The voltage applied across the string of the suspension insulators is not uniformly distributed across the various discs, i.e.
String efficiency of suspension insulator is defined as the ratio of voltage across the whole string to the product of the number of insulator discs and the voltage across the insulator disc nearest to the line conductor. Was the corning pyrex no. These insulators are cheap for. Suspension insulator string is widely used as insulator structures in high voltage overhead power lines.
The disc nearest to the line conductor has much higher potential than the other discs.
The suspension insulator is the one which consists of a number of porcelain discs connected in series by metal links in the form of a string. Each suspension disc is designed for normal voltage rating 11kv. A suspension insulator strain consists of a series of alternately insulators and metal parts, which bind each insulator to the next. When the insulator string used in the horizontal, it is called a string insulator.
Insulator strings are consist of dish insulators made of insulating materials such as glass, porcelain, or polymer.
This constitutes a series of connected capacitors , with each one’s capacitance being created by two successive metal connectors ( clips ) with the porcelain as a dielectric. Just the same as the string insulator, a suspension insulator is a flexible insulator string that consists of some porcelain or glass disc insulators connected with each other by metal connections. Modular suspension insulators are custom products typically used for applications of 230kv and above. In suspension insulator numbers of insulators are connected in series to form a string and the line conductor is carried by the bottom most insulator.
The conductor is connected at the bottom of the string.
A suspension insulator is basically a string of number of porcelain disc connected in series though metallic link. The suspension insulator is shown below. Each insulator of a suspension string is called disc insulator because of their disc like shape. This type of insulator is also called a suspension insulator, and the number of insulator discs connected depends upon operating voltage.
Therefore, each disc forms a capacitor c as shown in figure(ii).
A string of suspension insulators consists of a number of porcelain discs connected in series through metallic links. String efficiency of suspension insulator when the voltage is applied across the suspension insulator string, it is unequally distributed across the individual unit. Suspension insulators or suspension strings are developed by attaching a number of closed insulators in series using metallic links. 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.
The conductors are suspended at the bottom end of the string as shown in fig.
It is widely used in medium and high voltages of transmission lines. The voltage across the nearest disc to the conductor is maximum than others disc. Available in 25k, 30k, 50k and 80k tensile strengths. Molded suspension insulators are standard products ideal for tension applications from 69kv to 161kv.
In which the conductor is suspended by the lowest insulator and the top of the insulator is protected by a cross arm.
Generally, in overhead transmission lines, we use a number of porcelain discs as an insulator that is arranged in string.
