Development of a Digital Inverter for Brown Gas Generating System

In this paper, an IGBT-based digital inverter (DI) operated at high frequency is proposed and applied to brown gas generating system (BGG). A PI controller is applied to control the DC current output of DI for tracking a setting current of the BGG system. The spark inside the electrolysis tanks is a very dangerous factor that makes the tank of BGG system be exploded. To overcome the problem, the proposed DI has a soft-start function to reduce a spark inside the electrolysis tanks of BGG system. Furthermore, the current and voltage of the electrolysis tank are checked at every sampling time by the DI under critical working condition of electrolysis tank. Therefore, the proposed DI (PDI) has the higher safe working condition than a conventional inverter for the BGG system. The PDI is operated at high frequency (20-30 kHz), has much smaller size, weight and higher efficiency than conventional one. The effectiveness of the PDI for BGG system is proven by the experimental results and durable test