This project assessed the ability of the FPSO’s electrical system to start new 1.5 MW motors within system operating limits and investigated the impact of the new motors on the number of generators required.

Arc Flash Safety Limited were requested to assess the feasibility of replacing the existing 0.3 MW motors on the FPSO with the new 1.5 MW units.

A load flow analysis was performed to ensure that the proposed design did not result in equipment overloads, that voltage levels across the system were acceptable, and that transformer tap settings were adequate. A fault level study was also undertaken to assess the systems short circuit levels and to confirm that both the existing and proposed switchboard fault withstand ratings are acceptable. Motor starting was analysed to confirm both the suitability of the equipment and to determine whether the system voltage and frequency limits would be exceeded during start-up of the new motors. The studies considered various options to supply the motor, i.e. direct-on-line, soft-starter and Variable Speed Drive (VFD) driven motors.

Recommendations to achieve satisfactory design parameters were proposed.