Difference between Transmission Lines and Distribution Lines
Transmission lines are designed for long-distance power transmission, operate at higher voltages, and require more maintenance. Distribution lines, on the other hand, are meant for shorter distances, operate at lower voltages, and require less maintenance. The differences between these two types of lines cater to their specific roles in the power delivery system.
| Basis of Difference | Transmission Lines | Distribution Lines |
|---|---|---|
| Definition | High voltage power lines carrying electricity from generating stations to substations. | Low voltage power lines carrying electricity from substations to distribution points and end users. |
| Length | More, it carries electricity over long distances. | Less, carrying electricity over short distances. |
| Voltage Level | Very high, usually more than 69 kV. | Lower, usually less than 69 kV (primary distribution), 440 kV (3-phase distribution), 230 kV (1-phase distribution). |
| Phase System | Always a three-phase system. | Can be three-phase or single-phase. |
| Number of Wires | Only 3 phase wires. | 4 wires, with 3 for phases and 1 for neutral. |
| Current Carrying Capacity | High. | Low. |
| Line Conductor Size | Larger conductor size. | Thinner conductor size. |
| Line Support | Supported by high steel towers. | Supported by wooden poles, RCC poles, and rail poles. |
| Power Handling Capacity | Comparatively high. | Less than transmission lines. |
| Directionality | Usually bi-directional. | Traditionally mono-directional. |
| Line Maintenance | Requires more maintenance. | Requires less maintenance. |
| Applications | Carries power from power stations to substations. | Carries power from substations to homes, businesses, industries, etc. |
In summary,
