A Novel Forty Nine Level Stacked Inverter Topology Using Low Voltage Devices for Drives

This paper proposes a new forty nine level stacked inverter topology using low voltage devices for drives applications. The forty nine level inverter is developed by stacking three seventeen level inverters. The seventeen level inverter is developed by cascading a flying capacitor inverter and three H-Bridges. The inverter can operate with lower number of voltage levels if any of the H-Bridges fail. The capacitor voltage balancing in the inverter can be done irrespective of modulation index and load power factor. The topology is further modified to reduce the capacitor and switch count. Also, the inverter does not use any pulse width modulation between the different voltage levels. Therefore switching losses are reduced. In addition, since the switches need to block only lower voltages, MOSFETs can be used which will further improve the efficiency. An induction motor driven by this inverter using V/f control is simulated in MATLAB simulink and both steady state and transient results are presented