The scientific objective was to investigate the cooperation of three-electrode plasma reactors with gliding arc discharge powered from multi-phase AC/DC/AC converters. In order to achieve the scientific and practical goal of the project, a test stand was designed and built, which included: a multi-electrode GlidArc type plasma reactor; a power-electronic AC/DC/AC converter, working as a source of voltage or current with regulated parameters of energy transferred to the discharge space; reactor operation diagnostics systems; and a process gas feeding and flow control system. The GlidArc Plasma Reactor has shown high sensitivity to changes in many electrical as well as gas chemical, gas-dynamic and mechanical parameters. The AC/DC/AC converter turned out to be a system sensitive to interference generated by the plasma reactor. It can be noticed that the operation of the reactor in certain conditions causes bigger interferences of the converter. However, it is difficult to systematise the influence of particular parameters of the reactor’s operation on the operation of the AC/DC/AC converter and vice versa due to mutual correlations of many parameters. The correct operation of a plasma reactor depends on the characteristics of the power supply system; on the other hand, the power supply system reacts to such an untypical receiver as a plasma reactor.