A computer-aided testing program for electrical apparatus (CATEA) is d
esigned to test the performance of single and polyphase electrical dev
ices. It has been applied to measure the losses of single- and three-p
hase ac and dc electrical machines, single- and three-phase transforme
rs with linear and nonlinear loads. On-line measurements of iron-core
and copper losses of single- and three-phase transformers with rectifi
er load are presented and compared with the results of the open- and s
hort-circuit tests.