Consideration of Dynamic Cross Saturation in Mathematical Modeling of an Asymmetrical Six-Phase SEIG for Wind Energy Applications

Abstract

Compared to three-phase, the multi-phase electrical machine technology renders a reduction in size and weight and an increase in efficiency and reliability of the machine. Self-excited induction generators (SEIGs) are preferred for wind energy conversion systems because they are simple, low-cost, and durable. It is vital to get comprehensive insights into an induction generator’s dynamic behaviour to develop an effective control system governing its voltage, frequency, and reactive power. This study analyses the performance of two non-linear models of an asymmetrical six-phase SEIG using stator and rotor currents as state variables. The mathematical models of SEIG differ in terms of the presence or absence of a dynamic cross saturation effect. Transient events, including voltage build-up, sudden load perturbation, and unloading of the six-phase SEIG, reveal substantial performance variations between the studied modeling approaches. When comparing the full model (which contains the cross-saturation effect) to the simplified model, the full model shows a faster steady-state convergence. Experimental and simulated results are presented to support arguments.