Letter from the Editor in Chief
This issue focuses on marine transportation electrification, an area that is not new but is witnessing a major revisit by the marine transportation and defense industries. As early as World War I and later World War II, submarines used electric motor propulsion and batteries in addition to diesel propulsion; examples include the US L-class, British R-class, German XXI-class, Japanese I-200 class, and other submarines. While the battery and DC motor weight and control were hindering factors, electrification of marine propulsion continued to be of interest. More recently, both commercial and military marine propulsion systems have returned to hybrid and pure-electric propulsion due to enhanced power electronic converters and devices, advanced micro-grid and motor drive control algorithms (since the power system on large marine vessels are like isolated micro-grids), and enhanced electric machines and insulation capabilities.
On the power electronics front, wide bandgap devices especially SiC IGBTs and MOSFETs, have enabled significantly high power, power density, and voltage for more compact converters and inverters. On the propulsion motor front, high-efficiency induction machines as well as high-power-density brushless DC machines have allowed for significantly higher power ratings at reduced losses and weight, mostly due to advances in materials and multi-physics machine design. Advanced controls, both at the propulsion drives level and at the vessel level, have allowed for more robust and reliable operation of a vessel’s electrical network.
In this special issue, we explore a commercial/civilian application of marine electrification, an article from the US Office of Naval research, and an article from the organizers of the IEEE Electric Ship Technologies Symposium (ESTS) which will be in Washington DC area during August 2017.