Steady state analysis of SEIG using fuzzy logic approach

For the self excited induction generators (SEIG), both the frequency (F) and the magnetizing reactance Xm which depends upon magnetic saturation, vary with load even when the rotor speed is maintained constant. The performance of SEIG can be calculated if the Xm and F are determined accurately. Therefore, a crucial step in the steady-state analysis of the SEIG for the given machine parameter, speed, excitation capacitance and load impedance is to determine the value of the frequency (F) and the magnetizing reactance (Xm) In the present work, a mathematical model employing the loop impedance method based on graph theory is used which results in simple formulation and is convenient for computer solution. The unknown magnetizing reactance Xm and frequency (F) has been computed using Fuzzy logic based algorithm. The frequency (F) and magnetizing(Xm) are computed separately using real and imaginary parts. The effectiveness of the method is tested through the simulation for simple shunt SEIG and series capacitor compensated SEIGs i.e. short shunt and long shunt SEIGs. The effects of change in capacitance and prime mover speed are also simulated. The analysis presented is validated by experimental results.