Buck-Boost Inverters with Symmetrical Passive Four-terminal Networks

Alternating voltage inverters (converters) supplied by low-voltage sources DC (ex. fuel cell, photovoltaic cell) are most frequently realized on the basis of the three fundamental topologies: a) PWM voltage inverter with non-transformer converter DC/DC in the "boost-converter" system, b) PWM voltage inverter with transformed converter DC/DC in the "boost-converter" system, c) PWM current converter. However none of these solutions is claimed to be the best and dominant over the others. Search for new and better solutions continues and among them one finds inverters with input symmetrical passive four-terminal networks, which features are very interesting. The paper describes work principles, attributes and potential of the buck-boost inverters system with symmetrical passive four-terminal networks. The paper focuses on the basic Z-source system and suggested new system of a inverter, which was elaborated by authors. Simplified theoretical analysis of both systems has been verified by simulation research. In the last section of the article, the possibility to build multilevel inverters based on diode clamped typology with new four-terminal networks is presented.