In general, ship supply networks are weak, and due to harmonic distortion and non-linear load, special attention should be focused on large AC Drive consumers. The Active Front End is a technology that frees us from the problems of harmonic distortion and improves the power factor. This enables and allows a higher ratio of the total generator load to be supplied to the AC Drives. This paper concentrates on the advantages of Active Front End AFE supplied diesel-eiectric propulsion, where the main part of the generator capacity is used by the AC Drives.rnThere are several ways to supply the propulsion motors in diesel-eiectric propulsion systems. The most common are three-phase or multiple-phase, naturally commutating rectifiers or Active Front End rectifiers.rnActive Front End rectifiers do not create the same amount of the harmonic distortion effects as naturally commutated rectifiers. Naturally commutated rectifiers also have lower true power factor and cause additional heating of the power supply chain components.rnWith the Active Front End, energy possibly generated by the propeller machinery can also be fed back into the shipboard power supply network. An Active Front End solution is also able to compensate for the poor power factor or harmonic distortion created by other devices connected to the supply.rnBy decreasing the harmonic distortion and increasing the installation power factor it is possible to optimize the total cost of the installation and the energy consumed during use. An Active Front End typically pays for itself several times over, during the initial investment phase.
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