I. Introduction
Three-phase alternating current, commonly referred to as three-phase power, is a form of electrical energy transmission. A three-phase AC power source is composed of three AC potentials with equal amplitudes, equal frequencies, and phase differences of 120° sequentially. Compared to single-phase AC power, three-phase AC power exhibits significant advantages in power generation and energy transmission: (1) In terms of power generation, three-phase generators can output higher power than single-phase generators of the same size. (2) In power transmission, for the same transmitted power, three-phase systems save approximately 25% of materials compared to single-phase systems. As a result, three-phase AC power finds wide-ranging applications, and electricity systems around the world commonly employ the three-phase system. Longdistance transmission of three-phase electricity is achieved through cables, which can be classified into single-core single-phase cables and three-core three-phase cross-linked cables.