Main losses study of cryogenic induction motor for submerged liquid natural gas pump

This paper discusses the main losses, including core losses, stray losses and rotor friction loss, in the cryogenic induction motor(CIM) for a submerged liquefied natural gas(SLNG) pump. Firstly, the calculation formula of core losses are modified by the low-temperature properties of silicon steel. Secondly, we propose a calculation method for stray losses, which is a combination of analytical magnetic circuit and finite element analysis. Lastly, the computation methods for rotor friction losses are established. By using the methods, we can obtain the efficiency of the cryogenic induction motor. And the results are compared with measured data.