The widespread use of power electronics converters for pump and propulsion motor drives in ships has introduced power quality concerns. The power-frequency current and voltage chopping done in these converters generate high-frequency harmonics on the bus.
Often, harmonic filters are installed on the bus, but they are
inadequate for highly harmonic-sensitive loads especially navigation electronics and some sensitive equipment. For such loads, harmonic-free power is generated using a motor-generator set.
The voltage generated by this set is completely isolated from the main bus, as there is no electrical connection between the two.