Abstract
The increasing penetration of wind and photovoltaic (PV) presents significant challenges to existing power systems. High levels of wind and PV integration introduce stability concerns due to the inherent variability when controlled to track peak power output and the resulting short-term uncertainty in their power output. This has underscored the growing importance of providing dynamically controllable real and reactive power to maintain grid stability. The static synchronous compensator (STATCOM) is a well-established solution for enhancing voltage and system stability through fast and precise reactive power control. In this study, a shunt compensator based on a modular multilevel converter (MMC)-based STATCOM is proposed for reactive power compensation. Most new STATCOM installations use delta connected MMC topologies. Energy storage can be added to the dc side of the MMC in the form of supercapacitors, creating E-STATCOM. A double-wye MMC topology is more suitable for adding storage on the dc side of the MMC, and that topology is used in this paper. A modified version of the IEEE 12-bus system is modeled and simulated using an electromagnetic transient simulator to evaluate its dynamic response under various operating conditions, both without compensation and with the proposed STATCOM. The simulation results confirm that integrating the MMC-based STATCOM substantially improves system voltage by effectively suppressing voltage fluctuations and meeting reactive power requirements. To ensure voltage regulation at the point of common coupling (PCC), the reactive power output of the STATCOM was calculated, demonstrating its ability to dynamically respond to changing system conditions and maintain voltage levels within acceptable operational limits.