Current‐Carrying Characteristics of High‐Voltage Land Cables With Different Grounding Methods for Low‐Frequency AC Transmission

ABSTRACT Low‐frequency AC transmission holds promise for high‐voltage land cables, but its ampacity is significantly influenced by cable grounding methods and other structural factors. To explore the specific low‐frequency current‐carrying characteristics of high‐voltage land cables, this paper conducts a thorough theoretical analysis of the coupling effects between transmission frequency and grounding methods on cable thermal balance. Through electromagnetic–thermal coupled finite element analysis, this study investigates the distribution of low‐frequency currents within the cables under different grounding methods and calculates the losses of the core and metallic sheath at various low‐frequency transmission frequencies. Furthermore, it analyses the low‐frequency current‐carrying characteristics of high‐voltage land cables and discusses the impact of parallel arrangements on these characteristics. The research findings demonstrate that the uniformity of core and metallic sheath currents induced by low‐frequency effects varies with different grounding methods, affecting the attenuation of skin and proximity effects and thereby influencing cable ampacity. This paper provides specific calculations of low‐frequency ampacity under typical specifications of high‐voltage land cables and offers a frequency range for selecting grounding methods in low‐frequency AC transmission, serving as a reference and basis for accurate capacity assessment and grounding method design in this context.