Classification and Application Scenarios of High Voltage Cables

The application of cables of different high voltage levels is extensive, and their selection mainly depends on the voltage level, transmission distance, load demand, and environmental conditions. The following are the classifications of common high-voltage cables and their typical application scenarios:
1. Medium voltage cable (1 kV~35 kV)
Typical voltage level:
3.3 kV, 6.6 kV, 10 kV, 20 kV, 33 kV
Application scenarios:
Urban distribution network: supplying power to residential and commercial areas, such as 10 kV cables widely used in underground distribution networks.
Industrial electricity: supplying power to large and medium-sized equipment such as factories and mines (such as motors and transformers).
Renewable energy: collection lines connecting wind farms and photovoltaic power stations (such as 33 kV).
Structural features:
Insulation material: cross-linked polyethylene (XLPE) or ethylene propylene rubber (EPR).
Conductor: Copper or aluminum, requiring a shielding layer to reduce electric field interference.
2. High voltage cables (66 kV~220 kV)
Typical voltage level:
66 kV, 110 kV, 132 kV, 220 kV
Application scenarios:
Regional power transmission: connecting the main power grid between cities (such as 220 kV cables used for cross regional power transmission).
Large industrial zone: provides direct power supply for high energy consuming enterprises such as steel mills and chemical plants.
Submarine cables: grid connection of offshore wind farms (such as 110 kV AC or DC cables).
Structural features:
The insulation layer is thicker and XLPE or oil filled cable (OF cable) is used.
Multi layer shielding and metal sheath (such as lead sheath) prevent moisture infiltration.
3. Ultra high voltage cables (220 kV~765 kV)
Typical voltage level:
275 kV, 345 kV, 400 kV, 500 kV
Application scenarios:
Long distance transmission: power transmission spanning hundreds of kilometers (such as 500 kV lines used to connect power plants with load centers).
Cross border power grid interconnection: such as the European cross-border power grid (400 kV).
Large capacity power supply: High reliability power supply for mega cities or giant data centers.
Structural features:
Liquid filled cables (such as low viscosity oil immersed paper insulation) or XLPE insulation.
A forced cooling system (such as water cooling or air cooling) is required to cope with high heat.
4. Ultra high voltage cables (≥ 800 kV)
Typical voltage level:
800 kV DC, 1000 kV AC (UHVAC), 1100 kV DC (UHVDC)
Application scenarios:
Ultra long distance transmission: reduce transmission losses (such as the transmission distance of China's ± 1100 kV ultra-high voltage project exceeding 3000 kilometers).
Cross border/transcontinental power grid: connecting remote energy bases (such as hydropower stations, desert photovoltaic power stations) with consumption centers.
Direct Current Transmission (HVDC): Long distance underwater transmission (such as the integration of North Sea wind power in Europe).
Structural features:
Complex insulation design (composite insulation materials or gas insulation).
Advanced monitoring systems (such as distributed temperature sensing) and anti electromagnetic interference technology are required.