Split-Output Hybrid Active Neutral-Point-Clamped Converter for MV Applications

Abstract

The higher cost of silicon carbide (SiC) devices is a limiting factor for their utilization in power electronic applications. This has led to the development of hybrid topologies by combining both silicon (Si) and SiC devices. This article proposes such Si/SiC devices-based split-output hybrid active neutral-point-clamped (S-HANPC) converter topology for medium-voltage applications. The proposed S-HANPC topology mitigates the shoot-through fault current and also provides protection against the crosstalk related issues for the SiC mosfets. Moreover, the strategically selected switching states in the modulation scheme of the S-HANPC topology optimize the loss distribution among the Si/SiC devices resulting in high efficiency. The split-inductors in the S-HANPC topology limit the overcurrent stress on the SiC switches and provides lower dv/dt in its output voltage without affecting its dynamic performance. In this article, the analytical method to calculate the optimal value of the split-inductors is given. Furthermore, it provides an investigation of the shoot-through fault current and losses in the converter switches. The effect of dead-time between the SiC switches on their switching performance is also analyzed using the experimental results of the double pulse test. The simulations and experimental results of the designed prototype validate the advantages of the topology.