Harmonic Mitigation in Offshore Power Systems; 24 Pulse VSD is Not Necessarily the Answer

The use of Electrical Submersible Pumps (ESPs) driven by Variable Speed Drives (VSDs) has dramatically increased due to the vast expansions of electrified offshore platforms in the Oil and Gas industry. Therefore, detailed analysis is required to study the impact on the offshore power system including harmonics associated with the operation of numerous VSD-driven ESPs, which could lead to distortion of voltage and current waveforms beyond acceptable standard limits. The problem becomes more pronounced when resonance is excited with the presence of long submarine cables and transformers. The authors conducted field measurements using power quality recorders and built a power system model to reproduce the field results using commercially available modeling software. Remedial solutions were studied to alleviate the impact of ESP operation on the offshore power system. Active and passive harmonic filters were studied in terms of effectiveness in meeting company standards for harmonic distortion.