Advanced Hybrid Excitation System with Enhanced Voltage Control for Self-Excited Induction Generators in Off-Grid Applications

This paper introduces a hybrid capacitor configuration to improve voltage regulation in Self-Excited Induction Generators (SEIGs) for off-grid applications. The system combines star-connected (2 µF) and delta-connected (12.5 µF) capacitors, overcoming the limitations of traditional excitation systems. Experimental results show that, under severe unbalanced load conditions (90% load variation), the hybrid system reduces the neutral current by 23.9% (1.953 A vs. 2.567 A), improves power factor (0.60 vs. 0.48), and enhances voltage regulation (±2% vs.±8%). Symmetrical component analysis confirms reduced zero-sequence components, validating better management of unbalanced loads. Total Harmonic Distortion decreases from 32.3% to 26.5%, indicating improved power quality. The configuration maintains these benefits across varying loads while keeping the system simple and cost-effective.