Performance Evaluation of Advanced Three-Level AC– DC Converter Fed Induction Machine Drive

Abstract

The topology of this converter is derived by combining a boost circuit and a forward circuit in one power stage. To improve the performance of the ac–dc converter (i.e., good power factor correction, low total harmonic distortion (THD) and low dc bus voltage), two bulk storage capacitors are adopted. Its excellent line regulation capability makes the converter suitable for universal input application. The operation of the converter is discussed in the project and its various modes of operation are explained in detail. Two independent controllers are majorly used to operate the converter namely an input controller that performs power factor correction and regulates the dc bus and an output controller that regulates the output voltage. They consist of an ac–dc boost pre regulator converter that shapes the input current and an isolated dc–dc full-bridge converter that converts the pre regulator output into the required dc voltage.  Research on the topic of higher power ac–dc single-stage full-bridge converters, however, has proved to be more challenging, and thus, there have been much fewer publications. They use passive elements such as inductors and capacitors to filter low frequency input current harmonics and make the input current more sinusoidal. Two stage converters, however, require two separate switch-mode converters (each with its own controller), and thus, can be expensive. Moreover, they have poor efficiency when operating under light-load conditions as there are two converter stages that are operating each with its own set of fixed losses while a small amount of power is actually transferred to the load. The converter is designed by using Induction Drive System for Irrigation Applications Matlab/Simulink software.

Index Terms— Induction Drive; three-level converters; Single-stage power factor correction (SSPFC); AC–DC power conversion