Theoretical Modeling and Experimental Verification of AC Resistance in Large Cross-Section XLPE Single-Core Cables

In recent years, the electric power industry has experienced rapid development, driving continuous expansion in the scale of power systems. In these systems, large-section conductors are responsible for crucial functions such as transmitting current, grounding protection, and busbar connections. Due to the skin effect, the alternating current (AC) resistance of large-section high-voltage cable conductors is significantly higher than their direct current (DC) resistance. This not only reduces the current-carrying capacity of the cables but also increases line losses, making accurate measurement of the AC resistance of large-section conductors critical. Most existing studies consider the AC resistance of cables under fundamental wave conditions; however, the widespread use of nonlinear loads has significantly increased the harmonic content in transmission lines. The impact of harmonics on additional losses in large-section cables is substantial and cannot be ignored. The calculation formulas in the IEC-60287 standard are only applicable to solid copper rods with cross-sections up to 1600 mm 2, and the current and voltage phasor measurement method it employs cannot directly calculate the AC resistance of large-section conductors under non-sinusoidal conditions, introducing certain errors. This paper first constructs a finite element simulation model for a 630 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> large-section cable conductor and calculates its AC resistance through simulation. Subsequently, an experimental testing platform for the AC resistance of large-section cable conductors was established, and the active power method based on electrical measurement was used to calculate the AC resistance. The experimental results, which are highly consistent with the simulation data, confirm the validity of the model, providing an important reference for measuring the AC resistance of large-section cables under harmonic conditions.