Switching Algorithms for the Dual Inverter fed Open-end Winding Induction Motor Drive for 3-level Voltage Space Phasor Generation

An open-end winding induction motor, fed by two 2-level inverters connected at either end produces space vector locations, identical to those of a conventional 3-level inverter. In this paper, two switching algorithms are proposed to implement space vector PWM for the dual inverter scheme. The proposed algorithms do not employ any look-up tables. The time consuming task of sector identification is altogether avoided in both these algorithms. The proposed algorithms employ only the instantaneous reference phase voltages for the implementation of the space vector PWM. An equal switching duty for both the inverters is also ensured with one of the proposed PWM strategies. Also, it is observed that the zero-sequence voltage in motor phases is significantly reduced with the proposed PWM strategies.