Modeling and experimental analysis of a self-excited six-phase induction generator for stand-alone renewable energy generation

This paper presents a simple d–q model of a saturated multi-phase (six-phase) self-excited induction generator (SP-SEIG). Performance equations for this machine are given which utilize the saturated magnetizing inductance Lm=(λm/im) and its derivative (dLm/dim) rather than dynamic inductance L=(dλm/dim). In the analytical model, the effects of common mutual leakage inductance between the two three-phase winding sets have been included. A detailed experimental investigation about the voltage build-up, collapse of voltage, and various performance including loading and unloading characteristic, power capability and reliability of six-phase self-excited induction generator is also presented in the paper. Experimental results are recorded: (a) with capacitor bank connected across both the three-phase winding sets, and (b) with capacitor bank connected across only one three-phase winding set. Loading and unloading transients are recorded with independent three-phase resistive loads at each of the two three-phase winding sets, and measured steady-state characteristics for various load and/or capacitor bank configurations. Experimentations were also carried out to judge the performance of the SP-SEIG when three-phase load was connected via an interposed Y−Δ/Y six-phase to three-phase transformer.