Circulating Common-mode Current Reduction in Open- End Winding Induction Motor

PWM Inverters in induction motor drives are known to cause common-mode voltage which results in leakage current flowing through the parasitic capacitors to the ground and creates drawbacks such as shaft voltage, bearing current, electromagnetic interference problems. CMV elimination using conventional Three-level NPC multilevel topology has certain drawbacks. An improved SVPWM strategy using Dual Two-Level Inverter fed open-end winding configuration is introduced which eliminates alternating CMV and also makes CMV across machine windings zero. Circulating current and associated problems are eliminated in the proposed configuration since the CMV of both inverters at any instant are made same and CMV across the machine windings are always zero. A comparative simulation study is done between conventional and proposed configuration and verified using MATLAB. KeywordsCirculating Common-Mode Current, Common-Mode Voltage, Open-End Winding Induction Motor.