The interaction of submarine cables and the power quality of an oil rig’s electrical system

Abstract

Electrical power systems are becoming more susceptible to disturbances in the power grid such as harmonic distortions. The reason for this is the improvement of power in electronics, which allows for more efficient motor control and starting techniques through electronic converters. However, the use of these devices distorts the voltage and current waveform of the power system due to the harmonics injection. In the case of production platforms and drilling rigs, there are several motors that are fed by frequency converters. These facilities have a peculiarity that worsens the harmonics issues, which is the risk of resonance, consequently causing voltage peaks that can lead to equipment damage. The risk of resonance is due to the use of long submarine cables that in turn, because of the long distances, have considerable capacitance values that can resonate with the inductance from the inductive loads such as power transformers. The present work aims to evaluate a platform electrical system in terms of power quality considering the situation of resonance caused by a submarine power cable. Overviews of the electrical system and of the adopted submarine cable model will first be presented, and then, the results of the simulations are discussed.