Characterization of electrical steels for high speed induction motor applications: Going beyond the standards

The objective of the present work is to assess the impact of improvements in standard characterization figures of merit of electrical steels, typically found in manufacturers catalogs (B₅₀ and W_10/400), in the performance of high speed electrical motors. From the motor manufacturer standpoint, changing to new materials may represent a complicated and costly procedure. Besides, the motor manufacturer has to deal with process variability and building tolerances that may overcome minor improvements in the electric steel. The electrical steel manufacturer has to deal with numerous process variables and long and expensive development times to come up with new products. Hence, even a small improvement in the B50 and W_10/400 figures are considered to be great achievements. In order to verify if such improvements really translate into real gains in electrical motors, a series of prototypes were constructed with newly developed electrical steels. The core losses of these prototypes were determined by the loss segregation method. Test results support the conclusion that the standard steel characterization figures of merit do not carry enough information for steel and motor manufacturers to conclude on the performance of an electrical steel grade. A datasheet of the electrical steel is proposed. Such datasheet carries useful information for the electrical motor designer and should also be used in the steel development process as a new product assessment tool.