Testing results of slow speed electrical machine, that can operate as a synchronous or double fed induction generator

This paper posses the construction of the electrical machine, which has the ability to operate as a synchronous generator with electromagnetic excitation or double fed induction generator. This generator can be applied for slow speed applications without using the gearbox e.g. wind turbine. The generator is multi pole with all of the windings placed on the stator. Rotor is tooth-like and has no windings on it. Primary winding is three phase, secondary winding is one phase. The testing results and practical research are also presented in the paper.