High-voltage power systems play a crucial role in modern power grids, as they allow electrical energy to be transmitted efficiently and economically over long distances. In China's power system, high voltage levels are widely used in transmission networks to reduce energy losses during transmission and ensure the effective distribution of large-scale electrical energy. The following are the applicable ranges for different high voltage levels:
500kV and above:
This is the highest transmission voltage level, used for ultra-high voltage transmission, primarily responsible for cross-regional, long-distance power transmission, as well as connecting large power stations and the main grid.
330kV and 220kV:
These voltage levels are typically used for the main lines of large power systems, serving as the primary voltage levels for inter-regional power transmission, suitable for long-distance transmission and interconnection of large power systems.
110kV:
Used for the main lines of medium and small power systems, and also as a secondary network in large power systems, connecting substations within regions to achieve local power distribution.
35kV:
It is the most commonly used voltage for urban and rural power distribution, used to distribute electricity from substations to commercial and residential areas, covering most urban and rural power distribution needs.
It is mainly used for internal power supply in medium-sized cities or large industrial enterprises, and also for rural power grids, serving as an important link between high-voltage and medium-voltage grids.
10kV:
3kV:
Limited to internal use in industrial enterprises, for example, to drive certain specific industrial motors.
The selection of each voltage level is based on factors such as transmission distance, power demand, economy, and safety. With the development of power technology, these standards may be adjusted, but the basic principles remain unchanged. The use of high voltage levels can greatly reduce current, thereby reducing energy losses and material costs on lines, while improving the efficiency and reliability of the entire power system.
