Common Mode Voltage Reduction in Space Vector Modulated Direct Torque Controlled Induction Motor Drive

Common mode voltage (CMV) can have detrimental effects on the performance of induction motor drive. The common-mode voltage causes leakage current to flow causing consequently unwanted tripping of switchgears, premature failure of bearings etc. This paper is focused on the mitigation of the resulting CMV and hence common mode current by reducing the number of transitions in common mode voltage. For this the three-phase two level h-9 inverter topology is presented in this paper. The proposed topology takes advantage of device junction capacitance (DJC) effect, occurring across switches in the OFF state, to achieve neutral point clamping. Further proposed topology is implemented on SVM-DTC and results are verified with simulation results.