Indexed on: 27 Nov '16Published on: 24 Nov '16Published in: International Transactions on Electrical Energy Systems
This article describes an accurate steady-state analysis of a stand-alone 3-phase self-excited induction generator (SEIG). This analysis, based on the Newton-Raphson algorithm, has shown that the system performance is greatly affected by the parameters related to the availability of primary energy, load variations, and excitation capacitor values. These parameters explain the stator voltage fluctuations and the output frequency decrease. To avoid any interruption of the excitation process and to ensure a good quality of the stand-alone minigrid, a three-phase voltage regulator (TPVR), based on switched capacitors, is proposed to keep the terminal SEIG voltage constant. The control algorithm and the regulation process are implemented using a microcontroller. The SEIG-TPVR is experimentally developed, and a variable capacitor bank is constructed. The experimental investigations on a 1.5-kW induction machine confirm the efficiency of the whole suggested system.