A Study on the Analysis and Control of No-load Characteristics of LLC Resonant Converter for Plasma Process

This study applied an LLC resonant converter with various advantages as a power supply for a plasma process. Owing to the nature of the process, it was necessary to analyze the no-load characteristics of the LLC resonant converter because the plasma power supply has an initial no-load operation. The conventional method for analyzing the characteristics of an LLC resonant converter shows the characteristics of the load condition well, but it is difficult to analyze the characteristics of the no-load condition. Therefore, this study analyzed the no-load characteristics of an LLC resonant converter as a method to consider parasitic components and analyzed them in the time domain. It also describes the control method with a duty ratio by the phase shift for operating the LLC resonant converter as a power supply for the plasma process through the analysis results.