The article presents applications of systems with power electronic converters, high voltage transformers, and discharge chambers used for nonthermal, dielectric barrier discharge plasma treatment of a plastic surface and decontamination of organic loose products. In these installations, the inductance of the high voltage transformers and the capacitances of the electrode sets form resonant circuits that are excited by inverters. The article presents characteristic features of the installations and basic mathematical relationships as well as the impact of individual parameters of system components. These converters with their output installations were designed, built, and tested by the authors. Some of the converters developed by the authors are manufactured and used in the industry.