IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 27, NO. 8, DECEMBER 2017 5204305 Load Test of 3-MW HTS Motor for Ship Propulsion Toshiyuki Yanamoto, Mitsuru Izumi, Katsuya Umemoto, Tamami Oryu, Youhei Murase, and Masahide Kawamura Abstract—This paper describes the test facility and load test program for a 3-MW high-temperature superconducting (HTS) motor for ship propulsion. The test facility was used to conduct a constant-load test and a variable-load test. The program consisted of the constant-load test, the variable-load test, and the inspection after tests. During the constant-load test, the motor efficiency was measured at various rotor speeds and torques, and the 100-h cu- mulative endurance test at 3 MW was completed successful. The variable-load test is composed of three different modes that sim- ulated an emergency maneuver of full astern to stop the ship and avoid a collision, and they have been verified. After the series of tests, the HTS motor was taken apart and an inspection confirmed that there was no problem with the HTS field coils or other main parts. This program demonstrated the reliability of the 3-MW HTS motor for ship propulsion. Index Terms—Coils, high-temperature superconductors, mo- tors, motor drives, superconducting coils, superconducting devices, superconducting rotating machines. I. INTRODUCTION T HE requirements for a propulsion motor used in com- mercial ships include high efficiency, compactness, high reliability, and low cost. A high-temperature superconducting (HTS) motor is a promising candidate that satisfies these re- quirements, and many studies are being conducted to examine different designs [1]. MW-class HTS propulsion motors have been built and tested, and they have demonstrated two of the requirements by estab- lishing their high efficiency and compactness. A design method for these motors has been established. American Superconduc- tor Corporation developed a 5-MW HTS motor in 2004 [2], [3] and a 36.5-MW HTS motor in 2007, with a full-power test con- ducted in 2008 [4]. Doosan Heavy Industries and Construction built a 2G (ReBCO) MW class HTS motor and performed a Manuscript received June 20, 2017; revised August 21, 2017; accepted September 7, 2017. Date of publication September 19, 2017; date of current version October 3, 2017. This paper was recommended by Associate Editor S. W. Schwenterly. (Corresponding author: Toshiyuki Yanamoto.) T. Yanamoto is with the Corporate Technology Division, Kawasaki Heavy Industries Ltd., Akashi 673-8666, Japan, and also with the Tokyo University of Marine Science and Technology, Tokyo 135-8533, Japan (e-mail: yanamoto_ toshiyuki@khi.co.jp). M. Izumi is with the Tokyo University of Marine Science and Technology, Tokyo 135-8533, Japan (e-mail: izumi@kaiyodai.ac.jp). K. Umemoto is with the Ship & Offshore Structure Company, Kawasaki Heavy Industries Ltd., Kobe 650-8680, Japan (e-mail: umemoto_katsuya@ khi.co.jp). T. Oryu, Y. Murase, and M. Kawamura are with the Corporate Tech- nology Division, Kawasaki Heavy Industries Ltd., Akashi 673-8666, Japan (e-mail: oryu_t@khi.co.jp; murase_youhei@khi.co.jp; kawamura_masahide@ khi.co.jp). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2017.2754270 Fig. 1. External view of a 3-MW HTS motor. preliminary test in 2015 [5], [6]. A 5-MW HTS propulsion mo- tor was tested at the sea state to demonstrate its use in practical applications [7]. We have developed a 1-MW motor over the period from 2007 to 2010, performed a load test at 450 kW [8], and established the basic design method. Since 2010, we developed a 3-MW motor that is applicable to the coastal vessel class, with the support of the New Energy and Industrial Technology Development Organization, and we successfully completed a 3-MW load test and achieved the world’s highest torque density in the MW class in 2013 [9], [10]. These developments also demonstrated the high efficiency and compactness of the motor. In 2012–2013, we built an HTS motor test facility for han- dling a constant load and a variable load with funding from the Ministry of Economy, Trade, and Industry (METI), and we per- formed a load test program for a 3-MW HTS ship propulsion motor in 2014–2016 to demonstrate its reliability. The program consists of: 1) a constant-load test; 2) a variable-load test; and 3) inspection after the tests. The purpose is to demonstrate the concept of the 3-MW HTS propulsion motor. This paper reports on the test facility and the load test program. II. 3-MW HTS MOTOR SPECIFICATION AND STRUCTURE The external view of the 3-MW HTS motor and its schematic structure are shown in Figs. 1 and 2, and the specifications are shown in Table I. The 3-MW HTS motor is a radial-type field-winding syn- chronous motor. The HTS field coils are of a racetrack type with a noniron core, and they are made of DI–BSCCO manu- factured by Sumitomo Electric Industries [11]. The rotor shaft 1051-8223 © 2017 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications standards/publications/rights/index.html for more information.