Experimental evaluation of inductor configurations and modulation techniques in an interleaved three-level DC/DC SiC-based converter

Abstract

This paper presents an investigation on a non-isolated, three-level DC/DC converter; more specifically, on the possible combinations of inductor configurations and modulation techniques directly affecting the performance of the converter. The many state-of-the-art and conventional solutions are compared theoretically, as well as based on experimental considerations founded on a medium voltage SiC-based DC/DC converter to be applied as an energy storage interfacing system in a fast charging station. The study focuses on the effects of the configurations on the output ripples of the converter, which is crucial for battery-oriented systems. The tests were performed at 1 kV and up to nearly 10 kW of power, successfully validating the use of each configuration. It is shown that for a system to operate in a wide output range, the current ripple criterion is not enough for choosing the optimal configuration, and other factors, e.g., efficiency, must be considered.