%0 Journal Article %T A Review on the Faults of Electric Machines Used in Electric Ships %A Dionysios V. Spyropoulos %A Epaminondas D. Mitronikas %J Advances in Power Electronics %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/216870 %X Electric propulsion systems are today widely applied in modern ships, including transport ships and warships. The ship of the future will be fully electric, and not only its propulsion system but also all the other services will depend on electric power. The robust and reliable operation of the ship¡¯s power system is essential. In this work, a review on the mechanical and electrical faults of electric machines that are used in electric ships is presented. 1. Introduction The idea to use electric power for the propulsion of ships is not new, as from the beginning of the twentieth century electric ship propulsion systems had shown advantages compared to the traditional ones using internal combustion engines. Since the 1980s, there has been an explosion in the number and variety of electrical propelled ships built around the world, from cruise liners to warships. Since the beginning of the last century, both AC and DC propulsion systems have been used. Moreover, the great evolution in the field of power electronics offered the means for efficient AC machines control, even in the case of high-power machines like those used in ship propulsion systems [1]. The ship of the future will be fully electric, as not only concerning its propulsion system but also all the other vital functions like navigation, and ship services will depend on electric power. To achieve this goal, the integrated power and propulsion system has to be designed properly in order to be robust, to achieve uninterrupted operation, to be fault tolerant, and able to continue its operation in case of failure through reconfiguration. Thus, timely hardware and electric propulsion machine diagnostics play a crucial role in maintaining the trouble-free operation of the ship. The ¡°heart¡± of the ship¡¯s integrated power system is the electric machine. The widespread application of electric machines for power generation, propulsion, thermal management systems, and so forth, makes their robust and reliable operation a crucial aspect. Usually, induction motors and permanent magnet motors are used in ship propulsion systems with high power ratings. In this paper, the most common electrical and mechanical faults of these machines are presented. 2. Modern Electric Ship Propulsion System The vast majority of ships are propelled directly from fossil fuel powered engines using mechanical transmission and gearboxes, as shown in Figure 1. The electrical part of such a system achieves 95% efficiency in nominal operation. Nowadays, an increasing number of ship propulsion systems manufacturers consider developing %U http://www.hindawi.com/journals/ape/2013/216870/