Modified single-phase AC-AC converter without commutation problem for single-phase induction motor drive application

Abstract

This paper proposes a modified single-phase AC-AC converter without commutation problem for single-phase induction motor. The proposed converter has no shoot-through and dead-time problems and, like conventional ac-ac converters, it can be operated with simple phase converter control. It offers high frequency and high efficiency operation because high speed MOSFET can be used as switching device without the reverse recovery issues and losses of system. The proposed converter features input and output currents, high input power factor, low total harmonic distortion of input and output currents, new commutation strategies for these converters are proposed and safe commutation can be achieved without computational circuit problems. The commutation strategies are easily to realize by sampling only voltage signals, and Analysis based on state-space averaging reveals the relationship between induction motor inductor and filter inductor current as well as voltage ratio. The design considerations of single phase AC-AC converter fed single-phase induction motor topology are given as an example. The computational-fed single-phase topology verified the unique features of single phase -source ac-ac converters and the proposed commutation strategies. These converters have merits such as less conduction and switching loss, fewer devices, therefore high reliability can be achieved. The proposed ac–ac converters have no circulating current and do not require bulky coupled inductors; therefore, the total losses, current stresses, and magnetic volume are reduced.