Where is it required and what quality of supply or reliability is required? When will a new transmission line, or uprating, or upgrading of existing lines will be required? Planning Studies should answer the following questions: Planning Aspects Regarding Transmission Lines Note: Planning should be continuously revised depending on the variation that can occur in the economic environment, the energy market, energy industry, or in the generation program.
PLS CADD STAKING TABLE UPGRADE
These includes but not limited to the anticipation of operation dates of new facilities, needs to uprate or upgrade existing lines, or load transfers in scheduled interruptions. Operation or Short Term Planning - The horizon to be analyzed is usually below three years and urgent requirements of the system. It usually defines the basic characteristic of the system such as voltage, main transmission lines and substations.ģ. Medium Term Planning - Its target horizon is in the range of 10-15 years. It comprises a long term horizon for the system planning usually in the range of 15-30 years.Ģ. Long Term Planning - It defines the basic future structure of an electric system. The planning activities have to start several years before the installation of new or expansion of existing transmission lines is to be implemented.ġ. The planning studies take a leading role in the definition of an electric system or its expansion. Planning process should be continuous, should have an interactive structure as to make an optimized future evolution use. Transmission Planning is purposed to define a transmission system or its expansions as to comply with the electric energy demand at specified quality and reliability criteria at a minimum cost. Dead-end structures at the end of a transmission line are generally identified by insulator strings in the strain insulators. It is specifically designed to withstand relative greater deal of stress and strain. These structures can be classified as tangent, angled, or dead-end structure, depending on how it is used in a line.ĭead-end structures, or strain-termination structures, are used wherever a transmission line ends. The general types of structures used on transmission lines are wooden poles, concrete poles, metal or steel poles, and lattice towers. This change in direction causes strain on structures, and the need to compensate from these strains causes the emergence of much type of Transmission Line Structures. But there are also instances wherein different types of structures and different types of lines are being put.Ī right-of-way may follow a straight path, or may change direction in order to avoid obstacles, which happen in many cases. In most cases, only one type of structure is used on a right-of-way. Transmission lines are normally constructed on a tract of land known as right-of-way. They are pin insulators, post insulators, and disc insulators.īefore we are going to discuss the classification of power lines, it is good to be acquainted with the concept of the Right-of-Way. Insulators are rated in terms of its electrical and mechanical handling capabilities.Īs for its usage, there are three types of insulators typically found on transmission lines. Porcelain insulators, like any insulators come in a variety of different shapes and sizes, to accommodate the insulator rating as well as its usage. Mullite us porous, its surface must be glazed with a high melting point glass to render its smooth and impervious for use in overhead line insulators. Porcelain is a multiphase ceramic material that is obtained by heating aluminum silicates until a mullite phase is formed. Porcelain is one of the most highly used insulator type along with glass and other synthetic materials. To be able to isolate conductors, insulators must be made of materials that offer a great deal of resistance to the flow of electricity. The second purpose is very important to operation since without some form of insulating material, electrical circuit cannot operate. Porcelain Insulators have two basic purposes on transmission lines:ġ.To support conductors and attache them to structuresĢ.To electrically isolate conductors from other components on a transmission line Since then, porcelain insulators have evolved and has found vast usage especially in the transmission lines system acting as insulators. Porcelain Insulators was originally used for insulation of telephone lines. Porcelain insulators (bell type) were first created in 1849 by Werner von Seimens.