Loss Minimization Method Based on Three-Phase Asymmetric Control for Doubly Salient Electromagnetic Generation Systems

A loss minimization method based on three-phase asymmetric control is proposed for doubly salient electromagnetic generator (DSEG) systems. The three-phase magnetic circuit of DSEG is asymmetrical because of the parallel structure of the stator poles. The DSEG has the problems of uneven flux density distribution and partial oversaturation. Iron losses are not uniformly distributed in the core and difficult to analyze and calculate. According to the load resistance and conduction angle, the fundamental and harmonic distribution characteristics of the flux density of the core are obtained, and accurate iron loss calculation is realized. The three-phase armature currents in DSEG are also asymmetrical in the armature windings, so the copper losses are not uniformly distributed. In addition, the loss composition of DESG is analyzed, and an online method to calculate copper and iron losses is proposed. The three-phase asymmetric control method is implemented with the copper and iron loss models, and the optimum conduction angle and optimum asymmetric conduction angle are determined through the perturbation observation method. The proposed method is proven to be effective through experiments.