Novel PSO-based speed-controlled multiple IM fed by 3-Level DC-MLI and FC-MLI with a mitigative investigation on CMV and Bearing Current

The Voltage Source Inverter (VSI) powered Induction Motor (IM) has gained standardization in the industry over the last two decades due to its numerous advantages. However, these motors exhibit increased vulnerability to bearing currents, ultimately leading to premature bearing failures. Within any Pulse Width Modulation (PWM) based inverter, a definite common-mode voltage is present, primarily accountable for the bearing current. This current traverses through parasitic capacitances developed between the motor frame and its winding. Implementing a Multi-level inverter configuration offers a potential solution to mitigate bearing currents by presenting multiple voltage levels, thereby constraining the common-mode voltage. Furthermore, a novel PSO-based algorithm is proposed that controls the speed of multiple induction motors fed with 3-level Diode clamped and Flying capacitor Multilevel inverters, evaluating the extent to which the tuning of the multiple motor speed is achieved. Later, a mitigative study for common-mode voltage and bearing current is presented and then highlights the advantages and limitations associated with the proposed novel speed-tuning algorithm.