New marine harmonic standards

To address concerns associated with electrical power system harmonic distortion on ships and offshore oil rigs and platforms, marine regulating bodies have introduced strict new harmonic standards. These standards define the acceptable level of harmonic voltage distortion allowed on the vessels they certify. High-harmonic distortion levels are appearing as a result of the increased use of power-electronic drive converters for electric propulsion, drilling and pumping applications, and many other uses of variable speed-drive (VSD) systems. To meet these new standards, methods to control harmonics must be adopted. This article will discuss some of these methods and present an application where a unique wide-spectrum passive harmonic filter was used to meet harmonic limits on a cable-laying ship that previously required the use of rented generators to allow operation of VSDs.