Electromagnetic evaluation of the impeller of a turbine using a high temperature superconductivity electromagnet

This study proposes an electromagnetic method for the evaluation of the condition of a turbine in a nuclear power plant. Experimental results of a small turbine driven by an electric motor are shown in this paper. A high temperature superconductivity electromagnet is applied outside the case of the turbine to provide excitation magnetic field. On the other hand, pickup coils are placed near the impeller inside the case of the turbine. The experimental results show that it is not only possible to detect the movement but also the condition of the impeller by applying the electromagnetic evaluation method. Moreover, an enforcement vibration experiment shows that the vibration increment as well as the main frequency of the vibration of the impeller can be detected when comparing the results of cases with and without enforcement excitation. (author)