Published Paper Details:

This paper deals with study of three phases Nineteen Level inverter fed induction motor drive. The nineteen levels are realized by cascading Two H- Bridges. The poor quality of voltage and current of a conventional inverter fed induction machine is due to the presence of harmonics and hence there is significant level of energy losses. The Multilevel inverter is used to reduce the harmonics. The inverters with a large number of steps can generate high quality voltage waveforms. The higher levels can follow a voltage reference with accuracy and with the advantage that the generated voltage can be modulated in amplitude instead of pulse-width modulation. The CHB topology consists of several H- bridges and dc sources. This topology is implemented to three-phase system. In the symmetric structure, the values of the dc voltage sources are same. However, in asymmetric topology the magnitudes of the dc voltage sources are unequal. Asymmetric CHB topology generates a large number of levels for the same number of components in comparison with symmetric topology for the same number of power electronic components. For asymmetric inverters, a new structure has been recommended in, which reduces the number of switches and dc voltage sources compared with the CHB inverter. However, for creating a large number of output. Multilevel inverters with more number of levels can produce high quality voltage waveforms. In this concept three-phase is used instead of single-phase and implemented for nineteen levels, which can generate a large number of levels with reduced number of IGBTs, gate driver circuits and diodes. A comparison is presented between proposed multilevel inverter and conventional cascade topology.