Cascaded H-Bridge Inverter for Wind Driven Isolated Squirrel Cage Induction Generators

Abstract

Abstract: This paper describes the simulation and
harmonics analysis of cascaded five-level H-bridge inverters
fed induction motor load drive for islanding mode applications.
The self – excited induction generator (SEIG) fed H-bridge
Multi-Level Inverter (MLI) for wind energy conversion
systems is chosen for several islanding mode applications. In
this paper, the SEIG (for standalone systems) fed cascaded five
level inverter for induction motor load applications are clearly
explained with the help of MATLAB / SIMULINK models. The
generated voltage of the wind driven SEIG is mainly depending
on the wind velocity fluctuations and appropriate load
conditions. The five level cascaded inverters have interface
with the wind driven SEIG. By choosing appropriate value of
Modulation Index (MI), the variable voltage and variable
frequency of the generator can be finely controlled. The
simulation and harmonic analysis of the proposed inverter will
be discussed, and the total harmonic distortion of stator
current for different modulation index at different switching
frequencies are evaluated and the speed and torque of
induction motor for different load torques are plotted.
Index Terms: Self – Excited Induction Generator (SEIG),
Variable speed Wind Turbine, Multi Level Inverter (MLI),
Induction Motor (IM), Modulation Index (MI).