Abstract
Matrix converters feature low switching loss, small electromagnetic interference filter, and the potential for achieving high power density. With the employment of wide-bandgap devices, such as silicon carbide devices, the converter performance can be further improved. For a safe operation of matrix converters, an overvoltage protection circuit is necessary to limit the voltage stress of the devices during fault conditions. Due to the high switching speed of silicon carbide devices, the topology and layout design of the overvoltage protection circuit is critical to ensure fast and robust protection for the devices. In this article, a detachable overvoltage protection circuit is designed for each phase leg of the matrix converter. The topology and hardware layout design are elaborated. A 15-kW full silicon carbide implemented matrix converter is built, and the designed overvoltage protection circuits are employed and tested.

Abstract
In this article, a novel topology generalization of a current source converter (CSC) that allows controlling of multiple single-phase ac converters independently sharing the same dc-bus, with the advantage of having a reduced number of conducting switches and a lower dc-bus current, is presented. A conventional n-output/port single-phase CSC that uses the same dc-bus needs to have n H-bridge converters connected in series, which means that it always has 2n conducting switches. The new topology allows generating any n ac output currents always having only (n + 1) conducting switches in a switching period. This represents (1 - 1/n). 50% less conduction losses when compared with the equivalent conventional multiport single-phase CSC. A scalar pulsewidth modulation to control the converters with switching optimization and its generalization is also presented. Details of topology, control strategy, and modulation are presented. Simulation and experimental results are provided to validate the theoretical approach.