Inspection and Monitoring Technologies of Transmission Lines with Remote Sensing

Yi Hu, Kai Liu

• Publisher: Academic Press
• Year: 2017
• Print ISBN: 9780128126448
• eBook ISBN: 9780128126455
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Inspection and Monitoring Technologies of Transmission Lines with Remote Sensing helps readers build a thorough understanding of new technologies and world-class practices developed by the State Grid Corporation of China—the organization responsible for the world's largest power distribution network. Monitoring the operational status of high-voltage transmission lines is critical in supply assurance and continuity. Given the physical size, geographical, and climate variances that transmission lines are subject to, remote sensing and inspection is a critical technology for power distribution organizations. This reference covers current and developing technologies, equipment, and methods for the safe and secure operation and maintenance of transmission lines, including satellite remote sensing technology, infrared and ultraviolet detection technology, helicopter inspection technology, and condition monitoring technology.- Covers operational and technical principles, and equipment used in transmission line inspection and monitoring, with a focus on remote sensing technologies and solutions- Covers power line fundamentals, remote sensing technologies, inspection technologies, fault detection technologies, and on-line monitoring- Focuses on practical equipment and systems parameters to ensure readers are able to meet operational needs- Covers control technologies that ensure safe and consistent transmission operation

Chapter 1

Parameters and characteristics of transmission lines

Abstract

With the rapidly increasing demand for electricity in China, many power transmission lines have been constructed and put into commercial operation, especially the UHV AC and DC transmission lines. The inspection and maintenance of those lines are demanding tasks. The electrical and mechanical parameters and characteristics of transmission lines are important for their operational safety and reliability, as those working on them should know. The general development and main structure of transmission lines are introduced in Section 1.1. The electrical characteristics of transmission lines, including the AC power frequency discharge feature, the lightning and switching impulse voltage discharge feature for typical air gaps, the varying voltage discharge features of air gaps, corona features, and the noise and radio interference features for transmission lines are discussed and analyzed in the first part of Section 1.2. The mechanic parameters and characteristics of transmission lines are introduced in the latter part of Section 1.2.

Keywords

Transmission line; electrical parameter; mechanic characteristic; discharge; inspection

1.1 General Development and Main Structure of Transmission Lines

1.1.1 General Development of High Voltage Transmission Systems—Current Status

Modern large power plants are mostly built in resource concentrated places, while most electricity load centers are clustered in industrial zones and metropolises. As the distances between power plants and load centers are long, high voltage, high power capacity, and long distance transmission lines are economical ways of transmitting electrical energy. Therefore, transmission lines, as an important component of a power system, carry out the functions of transmission and distribution of electrical energy. To reduce electrical power loss in the process of electric power transmission, different voltage classes are adopted for transmission lines, based on transmission distance and capacity [1].

In 1882, the French physicist Deprez was the first to complete a long-distance direct current transmission test, which had practical significance that resonated in the history of the electric power industry. Through a 57 km telegraph wire (a steel wire 4.5 mm in diameter), at a voltage of 1500–2000 V, the electrical energy generated by the direct current generator (installed in Miesbach coal mine) was transmitted to the first electrically lit international electrotechnical exhibition, at the Glass Palace in Munich, and used to provide electricity for a set of foundation pump motors. After the 1880s, the application in engineering of alternating current transmission technology began. In 1891, the Frankfurt power line, the world’s first three-phase alternating current high voltage transmission line, running from Laufen to Munsen Riverside, with a total length of 175 km and voltage of 15.2 kV, was put into operation in Germany.

In 1908, the first 110 kV transmission line was built by the United States, and the first 230 kV transmission line was built and put into operation in 1923. After the 1950s, the world power industry developed rapidly, voltage class was continuously increased, and the scale of power grids was continuously enlarged. In 1952, the first 380 kV alternating current transmission line in the world was put into commercial operation in Sweden, followed in 1964 by the world’s first 500 kV alternating current transmission line; 735 kV, 750 kV, and 765 kV transmission lines were built in Canada, the Soviet Union, and the United States successively during the period of 1965–69. Later, some countries also conducted research on ultra-high alternating current transmission technology.

Meanwhile, project construction for direct current transmission systems was also rapidly developed. Following the success of the high voltage direct current transmission project of the island of Gotland, Sweden, put into industrial operation in 1954, the total number of high voltage direct current transmission projects put into operation worldwide until the end of 2008, was more than 76, and the total power capacity topped 70,000 MW. More than twenty 450–600 kV direct current transmission projects were included.

In 1954, the first 220 kV high voltage transmission line self-designed and constructed by China was built; in 1972, the first 330 kV extra high transmission line in China was built; in 1981, the first 500 kV extra high transmission line was put into operation, and China became the eighth country with a 500 kV extra high transmission line; an 1000 kV ultra-high alternating current transmission line was put into operation in 2009, making China the country with the highest voltage class of alternating current transmission, a status it retains today [1].

Though direct current transmission research and project construction were embarked on later, their development was rapid. In 1978, the Zhoushan HVDC transmission project with Chinese independent technology was put into commercial operation, and then the application and development of direct current transmission began in China. At the end of 2009, the Yunnan–Guangdong ±800...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Chapter 1. Parameters and characteristics of transmission lines
• Chapter 2. Remote sensing and remote measurement technology of transmission lines
• Chapter 3. Tour inspection technology of transmission lines
• Chapter 4. Transmission lines detection technology
• Chapter 5. Devices and technology for monitoring transmission lines
• Index