Abstract: Short-circuit current thermal capacity is a critical parameter in the design of OPGW cable. For the OPGW cables with the same structure, a big difference exists in the recommended values between the enterprise standard and the state grid material database. In accordance with the code provisions, a comprehensive comparison and analysis is made on the calculation methods and parameter values of short-circuit current thermal capacity. For the OPGW cables with the aluminum-coated steel structure, the calculation parameters of steel and aluminum conductivity are reasonably selected. The calculation method of short-circuit current thermal capacity is simplified by adopting the comprehensive specific heat method. The results show that the short-circuit thermal capacity values recommended by the enterprise standard are significantly smaller than the normal, and recommended values in the enterprise standard and the state grid material database can be checked and corrected by the simplified calculation method.

Key words: optical fiber composite overhead ground wires, short-circuit current, thermal capacity, specific heat, current density