Comparison between two solid-state transformerless modulators for capacitive type load applications

Two repetitive solid-state transformerless topologies, respectively, a Marx type circuit and a Voltage Multiplier (VM) pulse topology, specially oriented for square pulse production with highly capacitive loads, are presented and compared in terms of energy stored, number of semiconductors used and voltage hold off by each device. Although the VM circuit has higher multiplication factor, the voltage held by each stage increases, compromising the voltage modularity. Simulation results, using PSPICE, with an electric equivalent plasma load circuit, showed that the charging process in the Marx circuit is more efficient.