# Supply Systems of Non-Thermal Plasma Reactors. Construction Review with Examples of Applications
## 6 Conclusions  
Non-thermal and non-equilibrium plasma can be generated by electrical discharges of almost any type. Cold plasma generation in vacuum or high vacuum conditions does not pose significant difficulties, even in high volume discharge chambers, but fabrication such a vacuum is expensive and requires special plasma reactor designs. Hence, there is a need to look for reactors in which cold non-equilibrium plasma can be generated under atmospheric pressure. Promising plasma sources for industrial scale applications are reactors with discharges in the presence of a dielectric barrier, atmospheric pressure plasma jets and gliding arc in multi-electrode systems. In most applications, the design of the discharge chamber of the plasma reactor and its electrodes is not difficult, however, the use of plasma reactors on an industrial scale is determined by its power supply system, which must meet specific requirements, resulting mainly from the non-linearity of the receiver, which is the plasma reactor, working at high voltage and frequency and the need for ignition. Equally important in industrial conditions is the electromagnetic compatibility of plasma reactor supplies, which in the case of power electronic systems with microprocessor control, may require shielding and the use of filters to remove radiated and conducted interference from a non-linear receiver to the power electronic and then to the mains [79; 80]. The main element of all plasma reactor power supply presented in the review is the transformer, which in appropriate implementation can meet most of the requirements for plasma power supplies. Owing to the transformer's cores nonlinearity, simple, reliable, low cost and efficient power systems, especially suitable for industrial applications, can be constructed. Furthermore, transformer-based systems are much more resistant to radiated and conducted interference generated by electrical discharges. Some disadvantage of a transformer power supply is its relatively narrow range of the discharge power control. AC/DC/AC inverters can operate both in the sine voltage or sine current regime. In the voltage regime inverter is suitable to supply DBD reactor while the current regime is most suitable to supply GAD reactor. Taking into account the electromagnetic compatibility, power supply system of GAD reactor with nonlinear transformers seems to be the better solution than electronic power inverter. Electronic modules of AC/DC/AC inverter are sensitive for GADs' origin interferences, that could propagate both through conduction and radiation and at some conditions can even destroy the supplier [80]. Push-pull topology using IGBT transistors to supply miniature gliding arc reactor allows to obtain the commutation auxiliary ignition in conditions of work with air as the plasma gas. Power supply has a high efficiency of energy processing above 91%, a wide scope of adjustment properties in the range of 13 kHz to 26 kHz and confirmed desired features in cooperation with the uGAD reactor. It guarantees the ignition of the discharge and maintains cyclical operation in a wide range of non-linearity parameters of the arc discharge resistance and generated plasma is very homogeneous both in air and in helium as processing gases [45]. The use of electrical resonance allows for higher power supply efficiency and higher power density factor of the power electronic converter. Resonant power supply system topology for DBD reactors, proposed in [56] allows continuous resonant frequency tracking. Precise identification of the APPJ power system parameters allow constructing efficient systems for the plasma treatment of the heat-sensitive surfaces.