(0091) Control of Open end Induction Motor by Multi-objective GA based Selective Harmonic Elimination PWM to reduce Zero Sequence Currents and Torque Ripples

Abstract

A Double inverter powered induction motor with open stator winding has\nfew benefits, including excessive error forbearance functionality, great\nflexibility and lesser rating of dc input voltage etc. For this\nConfiguration, two types of Modules can implement they are Non-isolated\nDC link and Isolated DC link. In these two, Non-isolated DC link is a\ngood choice due to effective DC-link utilization and ruggedness, which\nis very beneficial in many applications. However, this module produces\nmore zero sequence currents (Z-SC) by means of common mode (CMMD)\nvoltage, which flows through Dc bus. The circulation of Z-SC must as\nlittle as feasible since it merely does rise the amplitude of currents\nin all phases. High ripple frequency of currents and torque, In addition\nresulting extra loss, which not alone reduces the efficiency, but\nloading ability and quickens the aging of drive. The triplen harmonics\ncan denote meticulously as harmonics with integer of three times the\nfrequency at fundamental, when they are in Phase in all Phases forms the\nZ-SC. In this paper, a novel SHE method is chosen to target triplen\nharmonics in Single DC Source Module (Non- isolated) and holding\npreferred fundamental quantity, which aids in improving the torque\nhandling ability of the motor. In addition, the investigation of dual\ninverter fed OEW-IM with both common DC source as well as separate DC\nsources also explored by SHE for different number of switching angles\nand variable Modulation Index (MI) towards the torque ripples and Z-SC\nreduction are given. The foremost challenge related with SHE method is\nthat resolving a set of higher order nonlinear equations with number of\nvariables. A Multi-objective GA method provided for that challenge which\neffects the reduction in Z-SC so that torque ripples will be minimised.\nMoreover, the novel SHE method reduces more number of harmonics than the\nconventional SHE, which further decreases TH-D with decent fundamental\nquantity. For validation, the essential mathematical formulations and\nsimulation results presented.