High-voltage overhead transmission lines can operate with either Alternating Current (AC) or Direct Current (DC), and the choice depends on the project's specific requirements, particularly the transmission distance and power capacity.

• HVAC (High-Voltage AC): This is the most common form of power transmission globally. It is highly effective for short to medium distances and is seamlessly integrated with the existing grid infrastructure. However, HVAC systems have losses due to factors like line capacitance and the skin effect, which limit their efficiency over very long distances.

• HVDC (High-Voltage DC): HVDC technology is the preferred choice for transmitting large amounts of power over extremely long distances, especially for subsea cables or connecting asynchronous AC grids. HVDC lines experience lower electrical losses and are more stable over vast geographical areas. The trade-off is the higher cost and complexity of the converter stations required at each end of the line.

At Ningbo Changshi, we manufacture high-quality Overhead Transmission line equipment for both HVAC and HVDC projects, including specialized tools and tension stringing equipment that are critical for installing and maintaining these complex systems.