# Analysis of Plasma Reactor Interaction with the Power Grid Depending on the Power Supply Design
## 5 Test Results
When changing the plasma-generating gas to helium, no significant changes in the current control ranges were observed for all the power supplies tested (Figure 13). In the  
Figure 14: Control characteristics of the tested power supplies loaded with plasma reactor, plasma gas: nitrogen, volumetric flow rate: 1.6 m\({}^{3}\)/h. Figure 15: Control characteristics of the tested power supplies loaded with plasma reactor, plasma gas: air, volumetric flow rate: 1.6 m\({}^{3}\)/h. case of the TPS, ITPS, and IFCTPS power supplies, there is a slight but noticeable increase in the voltage at which the electrical discharge in the plasma reactor burns. In the case of the PCS converter power supply, the helium discharge burns at voltage values similar to the burning voltage of the argon discharge. When the discharge burns in nitrogen in the plasma reactor, the control characteristics of the ITPS and IFCTPS power supply deteriorate (Figure 14). For the ITPS power supply, the discharge burns at about twice the voltage as when argon and helium are used as plasma gases. The control range of the discharge current in the case of discharge in nitrogen is also shortened by a factor of two. Even worse is the control characteristic of the IFCTPS power supply, which is reduced to a single point. With this power supply, the discharge in the plasma reactor when the plasma gas is nitrogen burns only at 550 V and 3.75 A. The TPS and PCS power supplies have the best control characteristics for discharge in nitrogen. Changing the plasma gas to atmospheric air does not significantly change the control characteristics of the feeders obtained for nitrogen (Figure 15), likely due to the fact that nitrogen makes up about 78% of the air composition. The study shows that the apparent powers for which all power supplies were designed are significantly higher than the maximum arc power generated in the plasma reactor. Table 5 shows the ranges of discharge powers than can be obtained in the plasma reactor for the different plasma-generating gases and compares them with the rated powers of the power supplies tested. Analysing the percentage ratio (Table 6) of the maximum power obtained in the burning discharge in the individual gases to the power rating of the power supplies, it is found that the highest ratios were achieved for the ITPS power supply of 8.9% for argon, 7.8% for helium, 13.3% for nitrogen and atmospheric air. The worst performer in this respect is the TPS power supply where 4.3% is achieved for argon and helium, 3.6% for nitrogen, and 8% for air. For the IFCTPS and PCS power supplies, these ratios are 5.5% and 10.9% for argon, 5.5% and 5.1% for helium, 4.5% and 7.2% for nitrogen, and 10.9% and 8.7% for air, respectively. A comparison between the rated powers for which the power supplies are designed and the maximum discharge powers burning in the plasma reactor shows that the power supplies operate in a state of significant underloading. This underload translates into low power factor and low efficiency of the power supplies. Table 7 shows the maximum efficiencies with which each power supply operates depending on the type of plasma gas. Efficiencies are expressed as the ratio of the electrical discharge power burning in \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Power Supply Type** & **TPS** & **ITPS** & **IFCTPS** & **PCS** \\ \hline Argon & 4.3\% & 8.9\% & 5.5\% & 10.9\% \\ \hline Helium & 4.3\% & 7.8\% & 5.5\% & 5.1\% \\ \hline Nitrogen & 3.6\% & 13.3\% & 4.5\% & 7.2\% \\ \hline Air & 8\% & 13.3\% & 10.9\% & 8.7\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Percentage ratio of maximum power obtained in the discharges to the power ratings of the Power supplies.