Effects of induction machine parameters on its performance as a standalone self excited induction generator

Abstract

A squirrel cage induction machine (SCIM) when aggregated with relevant capacitances and a prime mover, acts as self-excited induction generator (SEIG). As it hosts energy conversion the parameters of SCIM have considerable impact on the power extraction capability of SEIG. An aspect which is missing from the available research on SEIGs is evaluation of the affects of its rotor’s moment of inertia (J) and per-phase stator winding resistance (Rs) on performance indices. This work investigates the impacts of these factors on a SCIM’s performance as series compensated, short shunt SEIG. The study considers two distinctly designed SCIMs, in terms of J and Rs, operated as SEIG. In order to simulate their performance a stationary reference frame dq model including non-linear saturation and cross coupling effects is developed and verified experimentally. Several key investigations based on series capacitance selection, losses and efficiency, on-load performance with different power factor loads, transient performance with load perturbation and variable speed operation are carried out. The study reveals that SEIG with high J and lower Rs gives considerably better performance than its counterpart. The conclusions reported in the study are important especially for standalone/off grid application of SEIGs.