Harmonic-based thermal analysis of electric arc furnace's power cables considering even current harmonics, forced convection, operational scheduling, and environmental conditions

Abstract

The thermal analysis of power cables to improve their lifetime and reliability is essential. Also, the current harmonics intensify the excessive heat condition of power cables. Although several research works have been introduced for harmonic-based thermal analysis of power cables, there is a research gap about developing a thermal analysis of power cable focusing on the even current harmonics. This paper tries to such a research gap by proposing a new harmonic-based thermal analysis of electric arc furnace (EAF) power cables, which considers even harmonics. The impacts of ambient conditions and the performance of air-forced ventilation of cable tunnels are studied in this article. The proposed method is applied to an actual steel company located in Iran. The simulation test results based on the finite element method (FEM) in COMSOL Multiphysics are compared with actual measured values to validate the proposed method. Test results illustrate the advantages of the proposed method. Moreover, different paradigms for the cyclic operation of EAFs on the thermal behavior of power cables have been analyzed. Simulation results infer that 4.8% inaccuracy (about 3 ̊ C) occurs in the thermal analysis due to neglecting the current harmonics. In addition, approximately 41% improvement is achievable by appropriate forced convection. Test results also imply that the maximum temperature of power cables could be effectively controlled by changes in the operation and scheduling of EAFs. Around 10% decrement in the cable system temperature could be obtained by 10 min increment time interval between two operating cycles of the EAF. Simulation results illustrate the advantages of the proposed study.