Modulation scheme with common mode and differential mode voltage elimination for a five level inverter fed open end winding induction motor drive

A five level inverter topology with single DC supply is analysed for an open end winding induction motor (OEWIM) drive. A carrier based modulation scheme is proposed to eliminate the common mode (CMV) and differential mode voltages (DMV). The modulation scheme utilises the voltage vector and switching state redundancy of the inverter topology. The voltage vector redundancy is used to eliminate the DMV and switching state redundancy is used to eliminate the CMV. Compared to the conventional level shifted PWM method, the proposed modulation scheme offers improved harmonic performance and also ensures self-balancing of capacitor voltages. The simulation studies are carried out in MATLAB for an OEWIM drive operating with open-loop constant Volts-per-Hertz control. The modulation scheme is implemented using TMS320F28379D controller board and an FPGA module.