Analysis of Skin Effect Influence in Underwater AC Transmission System

Marine petroleum resources have become a new growth point in the global energy industry. The development of deep-sea oil and gas fields requires the use of numerous underwater electrical equipment, which makes the cost of employing underwater transformer systems for underwater power supply difficult to bear. On the other hand, underwater AC power transmission systems are suitable for establishing underwater distribution networks and supplying power to equipment within a small range by placing variable frequency drives (VFDs) underwater. However, the underwater VFD system contains a long high-voltage umbilical cable, and the stability and reliability of the system are greatly influenced by the length and impedance characteristics of the cable. In this paper, a long cable model considering frequency characteristics is analyzed and utilized to simulate the skin effect. A submarine AC power transmission system was constructed, and through simulation analysis, a comparison was made between the harmonic magnitudes before and after considering the skin effect of long cables.