Innovative design and feasibility study for a subsea electrical submersible pump system

In this paper, a subsea electrical submersible pump (ESP) system with challenging long cabling requirement is designed. Several factors are considered for the design: configuration of the system, length and size of the subsea cable, and load filter parameters for a medium voltage variable frequency drive used in the system. The system requires a 4 km or a 50 km subsea cable connected to the output of the drive. With such long cables, harmonic resonance and motor start-up are two major concerns. Various system designs are investigated through a feasibility study by computer simulation, which includes a steady-state analysis, a frequency response analysis, and a motor starting study. New designs of the load filter for the medium voltage drive are proposed due to unsatisfactory performance of its original standard load filter from the drive manufacturer. The frequency response analysis combined with the steady-state analysis are used to evaluate the effectiveness of new load filters. The motor starting study determines the possibility if the motor can start-up successfully for a system design. The acceptable designs of the system are finalized based on results of the feasibility study.