Hybrid excitation machine with isolated magnetic paths

In order to extend the speed operation range for the constant generating voltage or the constant motoring power of the electrical machine, a new hybrid excitation machine with isolated magnetic paths is presented in this paper. The structure of the machine is described and its operation mechanism is analyzed in details. As an example, a conceptual prototype machine integrated with a rotating-armature AC exciter (brushless) is simulated with finite element analysis and is tested to verify the field adjusting characteristics of the machine. The simulation result is given in comparison with the measured result. The results are well agreed as expected.