power systems loss

BUNDLED CONDUCTORS IN TRANSMISSION LINE Bundling of conductors in a transmission line is a product of experts' ingenuity. In support to this post regarding bundled conductors, we will discuss here how bundling of conductors can affect the losses in the transmission lines. Bundling of conductors in the transmission lines helps lessen the effect of the two major phenomena the exist especially in voltage levels of 220kV and up namely; the CORONA effect and the SKIN effect .  Corona, also known as partial discharge, is a type of localized emission resulting from transient gaseous ionization in an insulation system when the voltage stress, i.e., voltage gradient, exceeds a critical value.   READ MORE >>> Skin Effect in AC circuit is the tendency of the current to crowd toward the outer surface. This results in a current density that is greater near the outer surface of the conductor.   READ MORE >>> Conductor bundling supports the s

In a network of electrical system, majority of the losses occurs in the lines particularly in the electrical conductors. Losses also varies in the kind of materials used to serve as a conductor whether it could be an aluminum, copper, gold, silver and so on. In the past, electric power were transmitted through the use mostly of copper conductors. Copper is rank among the most ideal metals for transmitting electricity due to its low resistivity also, of which it is second to silver. However, in the modern days, aluminum replaced copper as a main material for transmitting electricity simply because of the much lower cost and lighter weight of an aluminum conductor in contrast to a copper conductor with the same resistance. Another advantage of an aluminum is when compared to a copper with the same resistance, aluminum tends to have a larger diameter. It is an advantage because with a conductor with a relatively larger diameter the lines of electric flux originating on the conductor will

Since the beginning of time where overhead transmission lines were first made, significant evolution occurred with respect to its construction and standards. Several technical innovations were realized as time goes by, not only to the way it was constructed but most especially to the materials that were used. Many of these components possesses its own respective electrical characteristics like the conductors and the connectors used. Image courtesy of http://www.nationalgrid.com/uk/LandandDevelopment/DDC/devnearohl_final/appendix2/ Understanding losses in the transmission lines not only means directly solving for the said value but most of the time it is by considering the materials and equipments involved in the construction which by virtue of many is the most prevalent way of analysis anyone should make. The following are the most common overhead transmission line components: Structures for Support (Poles & Towers) Wires and Cables (phase conductors & OHGW) Insulators

Before we dig deep into the principles of Transmission Line Losses, let us first review a brief history of the power transmission line particularly with Overhead Transmission Line. (courtesy of wikipedia ) The first transmission of electrical impulses over an extended distance was demonstrated on July 14, 1729 by the physicist Stephen Gray, in order to show that one can transfer electricity by that method. The demonstration used damp hemp cords suspended by silk threads (the low resistance of metallic conductors not being appreciated at the time). However the first practical use of overhead lines was in the context of telegraphy. By 1837 experimental commercial telegraph systems ran as far as 13 miles (20 km). Electric power transmission was accomplished in 1882 with the first high voltage transmission between Munich and Miesbach. 1891 saw the construction of the first three-phase alternating current overhead line on the occasion of the International Electricity Exhibition in Fr

Transmission and Distribution in an electrical power system consists primarily with conductors and lots of conductors. Overhead power lines usually uses ACSR or Aluminum Cable Steel Reinforced. As the name describes, this cable is made up of two metallic components. An Aluminum, which is known to be an excellent conducting medium and not to mention cheaper compared to other metals with the same or similar characteristics. The other component of course is the steel which serves as the main support of the conductor since compared to an aluminum, steel has a higher tensile strength. ACSR Conductor ACSR conductors are also known for its aluminum to steel ratio (i.e. 18/1, 26/7, 45/7). This also describes the stranding of every ACSR cable. ACSRs are also known to have code words which individual has different intrisic characteristics and they are usually taken from the names of birds others are from animals. The table below shows a simple listing of different types of ACSR c

Bundled Conductors Bundling of conductors in transmission line has been  studied for as long as the transmission lines were first  constructed.  Bundle is define in the webster dictionary as several objects or a quantity of material gathered or bound together. As for the case of conductors in a transmission line, bundling is also a good way in minimizing power loss . An in-depth discussion of this will be tackled in the coming articles, as for now, we will discuss the general purpose this type of application is made for. 4 Conductors Bundled Creating a bundle of conductors is done by having two or more conductors per phase. This is usually applied in voltage level ranging above 230 kV. This level of voltage rating is also popularly known as EHV or extra high-voltage. If you are wondering how bundling of conductors can help reduce losses, let us first go back to the very basic of electrical study. Recall that electric current passes more through less resistive conduct

Classification of Transmission Line There are three major approaches in analyzing transmission  lines in a power system, the Short, Medium and  Long transmission line analysis.  These three classifications affects the analysis since certain electrical parameters are considered which differ from one to the other. According to the book of William Stevenson Jr. entitled "Elements of Power System Analysis" , in an open wire 60hz line, it is said that; Short Lines is less than about 80 kilometers (50miles). Medium Lines are between 80 kilometers (50 miles) and 240 kilometers(150 miles) Long Lines are longer than 240 kilometers(150 miles). In an overhead lines that is classified as short, the major line parameters that are considered is the series resistance and the series inductance of the line. The power dissipated in this two parameters practically also represents the line loss of the conductor. Shunt capacitance is not considered in the analysis of short lines

Transmission lines are popularly known by many especially by those with minimal background with electrical power system as steel structures with conductors attached to it and fortunately, they are somewhat right. The image below shows an overhead line with conductors which are suspended from the steel structure and are insulated from it and from other conductors by insulators. Widely used insulators for transmission line are the polymer type   and the traditional porcelain type. With the case of insulators with porcelain, the number of which is determined by the voltage of the line.  Typical Transmission Line Transmission lines can be designed in many ways depending on the terrain and the electrical parameter requirements. In power flow analysis, transmission lines are usually categorized in to three approaches; short, medium, and long transmission line. Distinguishing one category from one another is determine through the circuit kilometer of the transmission.  Transmissi