Shipboard Power Generation: Design and Development of a Medium-Voltage dc Generation System

This article reports on the design, development, and validation of advanced prototype 2 MVA generation equipment [i.e., naval package (NP)] for a shipboard medium-voltage dc integrated power system (MVDC IPS). The generation equipment is based on an ultrahigh-speed 22,500-r/min 12-phase alternator, which feeds an ac/dc power electronics converter comprising four diode rectifiers and four insulated-gate bipolar transistor (IGBT) choppers. The prototype realization constitutes a follow-up of a previous NP version employing a wound-field 6,300-r/min alternator feeding noncontrolled ac/dc converters. The major technical challenges faced in the design and development of the advanced NP prototype are outlined in this article, taking the previous lower-speed version as a technology reference. The system performance, as determined by the testing campaign, and lessons learned for future studies are addressed.

Power Generation in MVDC Systems

The most important navies in the world are adopting electrical propulsion in many new projects and constructions. One of the most promising developments of this technology is the MVDC IPS, for which an IEEE standard was recently published [1]. Challenges related to the implementation of the MVDC IPS were investigated in [2] and involve subsystems technology, system integration, controls, fault tolerance, power quality, reconfiguration, power management, and electric grounding and safety. Power generation is certainly one of these key issues as the MVDC IPSs are designed to employ different types of power sources, such as electric machinery, accumulators, and fuel cells. With regards to electric machinery, generators come in different types (wound rotor, permanent magnet, multiphase) and sizes, have different primary movers [diesel engines, gas turbines (GTs)], and work at different or even variable speeds and loads.