An adaptive hysteresis band pulse width modulated inverter induction motor drive

An adaptive hysteresis band pulse width modulated inverter drive for an induction motor is designed and developed in this thesis. Existing constant hysteresis band controllers exhibit a varying inverter frequency which causes undesirable harmonic heating and losses in the motor. A previous study provides a generic derivation of an adaptive bandwidth to minimize the frequency variation. In Chapter 2 of the thesis, this adaptive band theory is modified for application to a squirrel cage induction motor. Chapters 3 and 4 discuss the design and implementation of a complete prototype drive system incorporating the adaptive band control. Chapters 5 and 6 give results of simulations and laboratory tests which suggest that the developed control technique is successful in reducing inverter frequency variations, and thus in improving the overall performance of hysteresis band induction motor drives.