# Analysis of Plasma Reactor Interaction with the Power Grid Depending on the Power Supply Design
## 2 Plasma Reactor  
A three-phase plasma reactor with gliding arc discharge of the GlidArc type [25], with the design shown in Figure 1 was used in the study. The reactor design parameters are displayed in Table 1. This reactor is used for gas decontamination processes, e.g., air pollutants generated in an iron foundry during the product coating process. The reactor has three knife-shaped metal working electrodes arranged around the axis of the cylindrical discharge chamber with a 120\({}^{\circ}\) spacing between them. Each electrode is supplied from a separate phase of the three-phase grid. The supply voltage to the working electrodes should not exceed 1.5 kV at a frequency of 50 Hz, and the supply current should be less than 5 A. With such supply parameters, a plasma is obtained which has the property of decontaminating air. \begin{table}
\begin{tabular}{l l} \hline Number of working electrodes & 3 \\ \hline Number of ignition electrodes & 1 or 2 \\ \hline Height/width/thickness of working electrodes & 140 mm/30 mm/2 mm \\ \hline Working electrode spacing, bottom/top & 5 mm/50 mm \\ \hline Working electrode material & steel 0H18N9 \\ \hline Ignition electrode material & tungsten, wire \(\mathcal{O}\)1 mm \\ \hline Height of the discharge chamber & 500 mm \\ \hline Discharge chamber diameter & 114 mm \\ \hline Discharge chamber material & quartz glass \\ \hline Material of the electrode clamping ring & aluminium PA6 (2017A) \\ \hline Electrode holder and current bushings & copper DIN CuCrZr \\ \hline Insulation of electrode holders & ceramics AL- 70 \\ \hline Gas inlet nozzle & \(\mathcal{O}\)5 mm \\ \hline \end{tabular}
\end{table} 
Table 1: Technical parameters of the plasma reactor. Figure 1: GlidArc-type plasma reactor, (**a**) overview drawing, (**b**) system with one ignition electrode, (**c**) system with two ignition electrodes, WE—working electrodes, IE—ignition electrodes. With the electrodes used in the reactor and the distances between them, a voltage value of 1.5 kV is not sufficient for spontaneous ignition of the discharge. Therefore, the reactor is additionally equipped with one or two ignition electrodes made of thin metal wire. The purpose of these electrodes is to initiate an electrical discharge at the working electrodes. The ignition electrodes are supplied with voltages up to 15 kV with a minimum frequency of 50 Hz but not exceeding 20 kHz, with a current value not exceeding 350 mA. These power supply parameters are not sufficient to ignite the arc discharge at the ignition electrodes, but they do allow the electric spark to jump over. A single ignition electrode initiates the spark discharge to the working electrodes. The initiated spark channels develop into an arc discharge due to the increase in power supplied to them from the working electrodes. With two ignition electrodes, the spark discharge burns between the ignition electrodes without the involvement of the working electrodes. These discharges reduce the electrical strength of the space between the working electrodes, which allows an arc discharge to ignite between them at reduced voltage. The operation of the GlidArc reactor is cyclic. Initiated by the ignition discharge, the right discharge burns on the working electrodes under the influence of the gas-dynamic forces caused by the plasma-forming gas flowing into the discharge chamber, and rises along the electrodes, increasing its length and volume. The nature of the discharge changes, moving from a short arc to a discharge with parameters similar to those of a glow discharge. The parameters of the generated plasma also change [26,27]. The discharge is extinguished when the power supplied from the power system cannot compensate for the energy losses of the intensively cooled and blown discharge. The end result of the plasma reactor cycle is a plasma column. As soon as the discharge is extinguished, it is rebuilt with ignition electrodes and the reactor cycle repeats.