Switched Reluctance Generator : An Alternative Source for Microgrid

A switched reluctance machine (SRM) has some advantages. Due to the absence of permanent magnets on its rotor, operating it as a generator requires two stages namely excitation stage and generation stage. Under the excitation stage, batteries are needed to excite the stator winding, this event must occur in proper commutation angles. These angles will determine the energy which will be produced during generation stage. SRM stator inductance will vary depend on the relative position between rotor and stator. A few moments before maximum value of the stator inductance, excitation to the stator winding must be given while turning off the stator excitation must be done during the negative slope of the stator inductance. In this paper, a method to generate precise commutation angles for SRM is proposed. This method is based on the input capture facility provided by dsPIC30F4012 as the core of the digital control. To verify the analysis, simulation and experimental works were done.