Novel modulation schemes minimizing the switching losses of sparse matrix converters

The switching losses of a three-phase sparse matrix converter (SMC) operating in the lower modulation range are minimized by employing the lowest and the second largest input line-to-line voltage for the formation of the converter DC link voltage. The resulting current stresses on the power semiconductors and the switching frequency ripple RMS values of the filter capacitor voltages and output currents are calculated by digital simulation and compared to conventional modulation. Finally, a modulation scheme is introduced which allows the generation of reactive input power also for missing active power transfer via the DC link and/or purely reactive load. This is a basic requirement for operating the SMC in boost mode where the output filter capacitor voltages have to be controlled sinusoidally also for no-load operation.