Reduction effect of excitation losses in a permanent-magnet-assisted salient-pole synchronous machine with narrow pole bodies

A permanent-magnet-assisted salient-pole synchronous machine (PMa-SM) that has narrower pole bodies than the conventional synchronous machine (SM) of the same size is built. The effect of reducing the excitation losses by the permanent magnets is verified by the measurements and the finite element analysis. As a result, the excitation loss in the PMa-SM is 26 % smaller than that in the SM under the rated load condition with unity power factor. Conversely, it is not smaller under the rated load with 0.8 lagging power factor.