Abstract:

In recent years, with the increasing popularity of distributed generation technology in the power network, its high penetration rate has posed significant challenges to the stable operation of the power system. As one of the key technologies to address the challenges of distributed energy grid connection, virtual synchronous machine (VSG) control technology has received deep attention from both academia and industry. VSG accurately simulates the core operating mechanism of traditional synchronous generators, including electromagnetic dynamics, mechanical motion characteristics, and frequency and voltage regulation mechanisms, endowing distributed generation units with a "behavior pattern" similar to traditional generators, thereby effectively improving their compatibility and stability in the power grid. This technological innovation not only provides technical support for the widespread access of distributed energy, but also opens up new paths for the safe and efficient operation of the power system. In order to provide the inertia and frequency modulation capabilities required by VSG, it is usually necessary to add energy storage units. In this regard, this study focuses on the research review of VSG control strategy based on energy storage state of charge. Based on the analysis of the current basic control model, it further demonstrates the application of several latest control strategies, including grid connected energy storage SOC control of VSG, SOC coordinated control of VSG and diesel generator networking system, and SOC balance control of multi VSG parallel system.

Key words: state of charge, frequency modulation, balanced control