In today's social life, we can't live without a resource, which is electricity. Not many people can't stand it. Without electricity, it means that there is no Internet for mobile phones, no electricity for cooking, no air conditioners in summer, no friends without paper money can't pay for money to buy things, etc. In industry, there is no electricity, and many factories can't start work. It can be said that not having electricity basically means returning to life before liberation. Electricity is very important in our life.

Power transmission

The invention of electric power technology and the establishment of electric power industry have a history of more than 100 years. Today, electricity is closely related to people's production, life, scientific and technological research and the construction of spiritual civilization. It has had a direct or indirect huge role and impact on all aspects of modern society, has become an important material foundation of modern civilized society, and is also a symbol of a country's hard power and an important economic indicator.

In 1831, Faraday discovered the principle of electromagnetic induction, which laid the theoretical foundation for generators. Scientific discoveries led to the invention of technology. In 1866, Wei Siemens invented the excitation motor and foresaw that the power technology has a bright future and will usher in a new era. Then, in 1876, Bell invented the telephone; In 1879, Edison invented the electric light. These three inventions lit up the road for human beings to realize electrification. Following the technical revolution of steam turbine, they led to the technical revolution of electric power.

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In 1882, Edison built the first regular power plant in the world, equipped with six DC generators, a total of 900 horsepower (1 horsepower=0.735kw, the same below), powered by 110V cables, with a maximum power transmission distance of 1.6km, for 6200 incandescent lamps, and completed the preliminary power industry technology system.

In 1881, Lucien Gollard and John Gibbs obtained the patent of "power supply AC system". The American inventor George Westinghouse bought the patent and built the alternator and transformer based on it in 1885. In 1886, the first single-phase AC power transmission system was built. In 1888, the flu response motor was manufactured. In 1891, the world's first three-phase AC generator was installed in the German Laufen Power Plant, and the first three-phase AC power transmission line was built. The appearance of three-phase alternating current overcomes the shortcomings of small DC power supply capacity and short distance, and creates a new situation of remote power supply. Besides lighting, power is used for electric drive and other purposes.

Thermal power plant

The emergence and development of electric power technology and electric power industry have changed people's production and life, and promoted the economic development at an unprecedented speed. The United States originally lagged behind the United Kingdom, Germany and other countries. The electric power technology revolution made the latter of the United States the most developed country. The wide application of electric power and the increase of electric power demand promote the development of electric power technology and industry towards high voltage, large units and large power grids. High voltage power transmission, large steam turbine generator and large hydro generator came into being and developed rapidly.

In 1960, 500000 kW steam turbine generator was manufactured in the United States and 1 million kW double shaft steam turbine generator was manufactured in 1963. In 1973, the United States put 1.3 million kW double shaft turbo generator manufactured by BBC into operation. In 1971, the Soviet Union put the single shaft 800000 kW unit into operation. In 1980, the single shaft 1.2 million kW unit in Kostrom Thermal Power Plant was put into operation, which is the only single shaft largest unit in the world.

Wind power generation

In terms of high-voltage transmission, Sweden first built the first 380kV transmission line in 1954. Since then, the United States, Canada and other European and American countries have successively used 330-345kV transmission systems. In 1964, the United States built the first 500kV transmission line, and the former Soviet Union also completed the 500kV transmission system in 1964. In 1965, ± 400kV DC transmission lines were built in the former Soviet Union. In 1965, the 765kV transmission line was built in Canada. In 1989, the former Soviet Union built a 1900km AC transmission line with the highest voltage of 1150kV in the world. By 1990, the world had 2.746 billion kW of power generation equipment, of which thermal power accounted for 64.9%, hydropower 23%, and nuclear power 12.1%. The world's power generation was 11734 billion kW · h.

With the development of electronic technology, computer technology and automation technology, the automation of electric power industry has developed rapidly. The modern electric power industry characterized by large units, large power plants, high voltage, large power grids and high automation has taken shape or is taking shape in different countries.