Experimental study of interleaved Y-Inverter performance

The Y-Inverter is rapidly gaining popularity as an alternative to the "dc-boost plus inverter" configuration in motor drive applications. Recently, advantages of designing with multiple interleaved cells per phase, as opposed to simply paralleling devices, have been pointed out and solutions using both coupled and non-coupled inductors have been proposed. This paper presents a detailed experimental benchmark study of the inverter performance when using non-interleaved and interleaved cells; for the interleaved case, both non-coupled and coupled inductors are considered. The results clearly show that interleaving enables an important reduction of the current stress on the output and input filter capacitors, as well as the possibility to design the magnetic components with higher energy density and higher efficiency. Interleaving clearly appears as a superior alternative to the straightforward paralleling of semiconductor devices, when the current ratings are such as to require multiple transistors anyway. Specific differences in the circuit performance optimization potential exist between the case of coupled and non-coupled inductors. Only the interleaved non-coupled case is presented here in detail, with some comparison results. All cases will be dealt with in detail in the final paper.