The development trend of substation

Before 1949, there were only a few 154 and 220 kV substations in Northeast China. After 1949, with the development of power construction, various regions have successively built 220 kV power systems. In 1972, a 330 kV substation was built in Northwest China. In 1981, the first 500 kV substation was built in Central China. Power station. Internationally, the United States, Canada, the Soviet Union and other countries have built 750 (765) kV substations. The Soviet Union completed the first 1150 kV transmission project in 1985, and Japan's 1,000 kV substation was also completed in 1992.

With the continuous growth of electricity load and the increase of load density, the voltage level and capacity of substations continue to increase. Not only the capacity of a single transformer is increased, but the number of transformers is also increasing, and the requirements for power supply reliability are also getting higher and higher. . At the same time, due to environmental requirements, it is becoming more and more difficult to select substation locations and line corridors. Therefore, substations are required to be reliable and occupy as little land as possible. In some cases, such as substations in central areas of large cities, it is often considered to be built underground. In order to meet these requirements as much as possible, the development trend is: First, simplify the voltage level and use high voltage to deepen the load-intensive areas, such as directly reducing 220kV to 35kV or below to reduce the number of substations, construction investment and power loss. The second is the development of high reliability, miniaturization and intelligence in equipment, and strive to prepare for moisture-proof, fire-proof performance and adapt to the requirements of environmental temperature changes, as well as extend the maintenance cycle and reduce the maintenance workload of the equipment as much as possible to achieve maintenance-free For example, the use of gas-insulated metal-enclosed switchgear of various voltage levels has become increasingly widespread. Due to the improvement of equipment reliability, the main wiring and auxiliary facilities of substations have gradually become simplified and typified, creating conditions for miniaturization, intelligentization, less land occupation, and even the construction of underground substations, and cooperate with them. The remote control, telemetry and other means in the system, as well as the automation facilities in the substation, such as equipment status monitoring, accident sequence recording, fault recording, and important parameter tabulation and printing, make the substation unattended.