EMI Aspects of Low Voltage Power Distribution Systems for Ships

Abstract

In many mission-critical systems, such as naval vessels, the power supply system is insulated. An insulated, or unearthed, system has no connection, or via a high impedance, to earth, and often the neutral is not used. An insulated system has drawbacks with respect to electromagnetic compatibility compared to the usual earthed power supply system, mainly due to the limited use of filtering possibilities. This paper provides a qualitative analysis of the advantages and disadvantages of insulated power systems and neutral earthing and the impact on electromagnetic compatibility.

Conducted Emission of a DC Motor Speed Drive: an Approach on Risk Assessment for Ship Application

“…As an example, the limitation of the total ground capacitance value. It is because those capacitors interfere with the detection of the first fault to the ground [6], [7] and contributes significant amount of leakage current [8]. Installing an EMI filter on ships can pose a big constraint in design [7], [9].…”