Electricity is an energy source that uses electric energy as power. Invented in the 1870s, the invention and application of electric power set off the second wave of industrialization. It has become one of the three technological revolutions in the world since the 18th century of human history. Since then, technology has changed people's lives. The large-scale power system that emerged in the 20th century is one of the most important achievements in the history of human engineering science. It is a power production and consumption system composed of power generation, transmission, transformation, distribution, and power consumption. It converts the primary energy of the natural world into electricity through mechanical energy devices, and then supplies the electricity to users through power transmission, transformation and distribution.