Low Voltage Electrician Practical Technology

Author: Chief Editor: Guo Zhongli
Publisher:
Publication Date: 1998-07-01
Features: This book is divided into sixteen chapters. It includes an introduction to practical techniques for low-voltage electricians; basic electrical knowledge; electrical diagram reading; electrical materials; low-voltage distribution equipment; AC and DC motors; electrical measurement instruments; low-voltage overhead lines and power cables; low-voltage lightning protection devices; indoor and outdoor wiring and lighting technology; reactive power compensation for low-voltage power networks; anti-static technology for factories and enterprises; rationalization of factory power supply systems; safe power supply and use technology; maintenance of electrical equipment; and practical operational techniques for low-voltage electricians. The book is rich in content, illustrated, easy to understand, and highly practical, making it a valuable reference for electrical technology management personnel and electricians in equipment and power departments. It can also serve as a technical training and job training textbook for a wide range of low-voltage electricians, including rural electricians, low-voltage shift electricians, maintenance electricians, and installation electricians.
Excerpt:
II. Superiority of Electric Energy in Application
The widespread use of electric energy is due to its superiority, which is demonstrated in the following aspects:
(1) Electric energy is easy to convert and causes less environmental pollution. Electric energy can be obtained by converting various forms of energy, such as hydropower (hydroelectric generation), thermal energy (thermal power generation), nuclear energy (nuclear power generation), chemical energy, and light energy. Moreover, electric energy can be converted into other forms of energy. For example, using a light bulb converts electric energy into light energy; an electric motor converts electric energy into mechanical energy; an electric furnace converts electric energy into heat energy; a speaker converts electric energy into sound energy; an electrolytic cell converts electric energy into chemical energy; and a coil wound around a core converts electric energy into magnetic energy, etc. Electric energy can also be converted among different forms, such as using a rectifier to convert AC into DC and using an inverter to convert DC into AC. In summary, the use of electric energy is extremely convenient. Additionally, compared to other energy sources, the use of electric energy causes less environmental pollution, or it can even be considered pollution-free. For instance, burning coal, oil, or liquefied gas produces smoke, which pollutes the environment severely, whereas using electric energy does not have this drawback.
(2) Electric energy is relatively easy to transmit. Electric energy can be transmitted over short or long distances by simply changing the voltage. To achieve ultra-long-distance transmission, AC voltage can be converted into high-voltage DC, resulting in longer transmission distances with lower losses. Therefore, the transmission of electric energy has lower power supply losses and higher efficiency. Electric energy distribution is also convenient, and for safety, it can be converted into safe voltage, making it even more convenient for people to use.
(3) The use of electric energy is convenient to control. For achieving remote operation and automation, electric energy can be used for remote control and remote measurement, such as the current quantitative devices and audio controllers in use. Moreover, when combined with computer applications, electric energy enables highly automated and intelligent systems. For example, electric energy can control production processes and production equipment, achieving programmed control, digital control, or optimal state control. It can also detect various parameters in production processes, converting them into electrical signals for automatic regulation and achieving management automation.
From the above-mentioned advantages of using electric energy, it is clear that the application of electric energy reflects the development of productivity and social progress. The use of electric energy plays a significant role in improving labor productivity in industrial and agricultural production and in advancing social productivity. Therefore, electrification is a necessary condition for industrialization and the automation of production processes. To develop a modernized strong nation, the power industry and electrification must be developed first.
III. Characteristics of Electric Energy in Production and Use
1) The production, transmission, distribution, and conversion of electric energy are simultaneous processes, meaning that the production, supply, and consumption of electric energy occur at the same time.
2) The production of electric energy must be highly centralized and unified. In the same power supply area, all power plants, substations, power supply companies, and large power users must be under the unified dispatch and management of the power system. This is determined by the inherent characteristics of electric energy, as it must maintain balance between supply and use at all times. In the power system, the quality of electric energy (voltage, frequency, and power supply continuity) is ensured through this centralized dispatch and management.
3) During the production and transmission of electric energy, electromagnetic transient processes occur very rapidly. In the power system, the operation and shutdown of various components are almost simultaneous. For example, in units with dual power supply, the automatic switching to a backup power source when one power source fails occurs almost instantaneously, leaving users without a power outage sensation. Moreover, accidents in the power system also occur in very short instants.
4) The production of electric energy requires forward-looking planning. That is, the development of the power industry must always be prepared in advance to support the development of other industries. The development of the national economy relies on sufficient electric energy supply. The development of industry, agriculture, defense, and science and technology are all related to our country's construction and the well-being of our people. To build a socialist strong nation that stands among the world's powers, the first step should be to develop electric energy production capacity and accelerate the construction of the power industry. Only by vigorously developing power construction can we resolve the conflict between supply and demand in power and meet the needs of socialist development and the electrification of urban and rural areas.
IV. The Role of Electricians
As mentioned above, electric energy plays a significant role in the national economy and holds a vital position. Electricians play a crucial role in industrial and agricultural production. For power networks of different scales, the power supply and transmission distances vary, requiring an appropriate number of electricians to manage, maintain, and operate the electrical equipment in the system.