This paper presents the impact results of the variation of the rotor and the stator tooth pitches (Vernier effect), on the waveform of the back-electromotive force (EMF) generated by the low speed Doubly Salient Permanent Magnet machine (DSPM). The rotating electrical machines with and without Vernier effect are designed and optimized using genetic algorithms combined with finite element method. The optimization of machines parameters is focused on the maximization of the mass to torque ratio. The results show that the machine with Vernier effect has better performances. The obtained Vernier slotted doubly salient permanent magnet generator is then integrated into an autonomous wind energy conversion system. Simulations tests are carried out through Matlab/Simulink. The results show that the proposed machine is a valid and inexpensive alternative for directly coupled wind turbines.
