Self-Excited Induction Generators (SEIG) Simulation and Behavioral Analysis for Application in Microgrid Hydro Power Generation

Abstract

Integration of Renewable Energy Sources into Microgrids has attracted much research interest because of the high demand for green and sustainable sources of electricity production. In this research paper, simulation and behavioral analysis of Self-Excited Induction Generators (SEIG) used for power generation purposes along with microgrid hydro turbine generators is presented. The performance behavior of the self-excited induction generator is analyzed in terms of dynamic performance in the process of voltage building up, during steady state and during load changes. In order to perform analysis of the performance behavior, a detailed model of the self-excited generator is created using the d-q reference theory. The mathematical model of SEIG incorporates a deep magnetic saturation exponent (n=5) and a numerical solver which takes care of electromechanical transients in the generator system and provides stable simulation results. Simulation of the SEIG model is carried out in MATLAB using the ode45 time-domain solver. From the simulation findings, it is clearly evident that there is a rather stiff terminal voltage curve because the drop is only 30 volts maximum at the point where the load is 4.0 kW (from 341.9V at no load to 312.2 V). This has been made possible by the efficient magnetizing inductance sustainment from the deep saturation model. Efficiency performance shows that maximum efficiency is achieved at 87.9% for 3.0 kW but reduced to 79.1% for 1.0 kW due to high impedance. The transient results prove that both the voltage and the frequency stabilize after an abrupt application of a 2.0 kW load. It is evident from the results above that SEIG can be effectively utilized in microgrids as it provides stiff voltage regulation; however, light-load efficiency needs to be considered.