An Online Method of Measuring DC Resistance of Transmission Lines Based on Simplified Distributed Parameter Line Model

Resistance is an important parameter that can reflect the loss of transmission lines. This paper aims to propose an online resistance measurement method of transmission lines that is suitable for engineering applications. First, based on the distributed RLCG parameter line model, the current and voltage expressions along the transmission lines are derived and a simplified RL distributed model is proposed. Then, the three-phase transmission line simulation model is constructed to verify the distributed RLCG parameter model and calculate the resistance. The results show that the current and voltage along the line obey the law described by this model, and the resistance can be effectively calculated. Finally, the current and voltage law along the actual transmission line is investigated based on the simplified RL distributed model, and the experimental results show that the model can effectively calculate the resistance which is obtained by interpolation method from series AC impedance in the low and medium frequency bands.