AC Drives with Buck-Boost Voltage Switched Frequency Converters without DC Storage

In general, this paper deals with the power electronics AC/AC converters without DC storage as supply sources for AC drives. In the paper are presented the solutions and basic properties of these converters, which allow the change of the output voltage frequency with possibility of obtaining the voltage gain greater than one. The presented description includes especially matrix reactance frequency converters (MRFC), current source matrix converters (CSMC) and Z-source matrix converters (ZSMC).