Modeling and Analysis of Long Cables in the Subsea AC Power Supply System

The underwater AC power transmission and distribution systems commonly employ long, high-voltage transmission cables. The accuracy of modeling these cables directly impacts the prediction of the system’s steady-state and transient performance. This paper presents an improved pi-section model for accurately modeling underwater AC transmission cables, taking into account the skin effect. Furthermore, we analyze the influence of the skin effect on the short-circuit input impedance of the cable. Through simulation verification, the proposed model precisely matches the actual cable parameters within the frequency range of 0 to 3000 Hz, confirming the impact of the skin effect on the short-circuit input impedance.