Impedance spectrum-based fault localization method for submarine cables on offshore oil drilling platforms

Due to the unique power supply forms and complex topological structures of offshore oil drilling platforms, submarine cable fault localization has become a critical challenge that urgently needs to be addressed. A new fault localization method for submarine cables on offshore oil drilling platforms employing unipolar power transmission is explored, based on the impedance spectrum of the electrode-submarine cable. The frequency domain model of the faulty cable is constructed using transmission line theory, and the characteristics and frequency variation mechanisms of the electrode-submarine cable power supply parameters are investigated, considering the electrochemical effects between electrodes and seawater. This approach facilitates the modelling of electrode-submarine cable impedance. By modelling the post-fault electrode-submarine cable impedance network, the input impedance is obtained, and a localization function related to the fault distance and impedance is extracted to achieve fault localization. The accuracy and effectiveness of this method are validated through simulation, demonstrating its capability for high-precision submarine cable fault localization. This method innovatively considers the impedance model of the electrode-seawater circuit for unipolar power transmission submarine cable systems, enhancing the precision of submarine cable fault localization.