A Highly Efficient Si-/SiC-Based Hybrid Active NPC Converter With a Novel Modulation Scheme

With the increasing demand for high-performance power electronic systems, the semiconductor device utilization has gained significant importance. This article proposes the Si/SiC devices based active neutral-point-clamped converter comprising SiC-based H-bridge structure. A novel pulsewidth modulation (PWM) scheme is also proposed that results in an effective utilization of the switching devices. In the proposed converter, the Si devices are soft-switched for all power-factor loading conditions. Therefore, high efficiency can be obtained even at high switching frequency operation with wide range of power factor values. Further, the conduction losses of the SiC
mosfet
s are minimized by strategically selecting the switching states in such a way that the SiC
mosfet
s conduct in parallel conduction paths during the null state operation. This leads to further enhanced efficiency. This article presents the detailed operating principle of the proposed topology operated with the presented PWM scheme. Moreover, a device loss analysis is presented to evaluate the conduction and switching losses of the proposed topology. The presented experimental results validate the performance parameters of the proposed topology with the proposed PWM scheme. Finally, the proposed PWM scheme is compared with the existing PWM schemes using efficiency values of the proposed and some of the prominent existing converter configurations.