Diode Clamped Multilevel Inverter Fed Induction Motor

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INTRODUCTION

Two level voltage source inverters produce an output voltage or a current with levels either 0 or ± Vdc

In high power and high voltage application these two level inverters, however, have some limitations in operating at high frequency mainly due to switching losses and constraints of device ratings.

Unique structure of ML-VSIs allow them to reach high voltages with low-harmonics without use of transformers


Multi-level Concept



Three phase multilevel power processing system is considered.

Emc=Vdc / (m-1) where m is no. of levels.

The term “level” is referred as the no. of nodes to which inverter can be accessible.

m-level inverter needs (m-1) capacitors