The main load on Penglai offshore drilling platform includes mud pump, winch, top drive, etc., which are adopts converter for drive.
The frequency converter adopts the conventional six-pulse diode rectifier, which will generate a large number of harmonics, mainly concentrated in 6n±1 times.
These harmonics seriously affect the safety of electrical equipment: causing serious voltage distortion, system power factor reduction, overheating of cables and transformers, accelerated insulation aging, power supply interruption is caused by instrument misoperation, all these will affect the stability and security of the whole platform power system.
Through actual detection, the total harmonic current generated by 7 inverters (6*600kW+1*920kW) is 581A. In the high drilling speed, the total harmonic current is 594A.
Finally, the active filter with rated current of 600A was selected accordingly.