An improved modular Statcom topology equipped with short-time energy storage and Grid Forming control for HV network voltage and frequency regulation

Abstract

The present paper describes a Second Generation Statcom, that is a Cascaded H-Bridge (CHB), in which each H-Bridge is coupled with Supercapacitor-based storage (SC assembly), through an improved DC/DC converter. A description of the device composing the proposed topology, together with its main advantages, and an overview to the SC technology, will be provided. A qualitative comparison with the Double-Star Modular Multilevel Converter (MMC) with centralized energy storage will be provided. The main features of the control algorithm will be described, paying attention to the loops and logics specific for the proposed topology, mainly the control of the capacitors and supercapacitor voltages. Finally, some realistic case studies, both with high and low short circuit power, will be described, and the relevant plots will be given, to prove the feasibility and the effectiveness of the proposed solution.

Postprint (author's final draft)