The increased deployment of renewable resources in the grid can lead to instability due to frequency fluctuation. Integrating energy storage system(ESS) into the grid is one solution to alleviate this instability. Therefore, many studies have been conducted on power electronic facilities for stable power transmission by utilizing ESS. Among various power electronic facilities, the integration of an ESS into a static synchronous compensator(STATCOM) using a multilevel converter has been gaining attention. This paper presents a multilevel converter with a zigzag transformer for E-STATCOM. The overall control techniques for the proposed configuration are described and validated through simulation.