Single stage transformer isolated high frequency AC link based open end drive

Abstract

An open end drive configuration utilizing a transformer isolated single phase high frequency ac link is presented. A high frequency ac link enables the use of a compact and light weight transformer to provide voltage transformation and galvanic isolation while the open end configuration leads to an improved utilization of the ac link. The desired output is synthesized using dual cycloconverters modulated using a space vector technique that has been modified to work with a high frequency ac link and leads to single stage conversion. Any change in the switch states is restricted to the zero crossings of the ac link to achieve zero voltage switching in the cycloconverters. The topology described also has the advantage of achieving natural commutation of leakage energy in the transformer windings and avoids the need for additional circuits to achieve the same. The proposed drive is simulated using MATLAB/Simulink and the results are discussed. A hardware prototype has been constructed to demonstrate the implementation of the proposed drive.