Understanding oil field power quality issues

Power quality in an onshore oil field is critical to continuous operation. Poor power quality can lead to equipment misoperation, premature failures, and process disruptions. These are undesired since they result in downtime. The authors realized there are separate power quality issues in the oil field´s 60 Hz system and the 0-60 Hz system (variable output of well VFD to the down hole submersible motor). The 60 Hz system issues include: (1) elevated harmonic distortion at distribution substations, (2) elevated voltage distortion at the point-of-common coupling (PCC), and (3) high voltage and current distortion at the well VFD input. The 0-60 Hz system exhibits elevated peak voltages at the output of the VFD putting stress on the step-up transformer, down hole cables and submersible well motor.