A Stacked 7-Level Common Mode Voltage Eliminated Inverter Scheme with Single DC-link for Open-End Induction Motor Drive

This paper proposes a 7-level common mode eliminated structure for an open-end induction machine (OEIM) using single DC-link with instantaneous control of neutral point voltage. The OEIM is fed with inverters from both sides, with each inverter formed by stacking three 2-level inverter and cascading two H-bridges. The inverters are operated such that zero common mode voltage(CMV) is obtained. All the capacitors in H-bridges are balanced using pole voltage redundancies irrespective of load power factor. No current is drawn from the neutral points of DC-link capacitors, thus the neutral point balancing of DC-link capacitor is achieved. The simulation and experimental results are also included to validate the scheme.