Introducing a classification method of Voltage dips in ship electric energy systems

Abstract

This paper presents an introduction to the analysis and classification of voltage dips, in a ship electric power system. The method followed covers the variety of dips occurring on shipboard installations in its entity. Thus although it has been primarily developed only for dips due to short circuit faults, it is shown that it can include the cases of sags due to motor starting, transformer energizing inrush or even pulsed loads. This method focuses on emerging and characterising the severeness of the event depending on the consequences on the operating equipment Therefore, besides an implement of assessing the significance of each situation it can be easily assimilated in system power quality monitoring units, in protection scheme design and evaluation processes or even in event identification tools. Where simulations are required, the software package PSCAD is used to simulate a number of case studies in the power system of actual vessels with electric propulsion.