A New Secondary Frequency Control Method for Distributed VSGs in Island Operation

The chapter delves into the challenges and solutions for secondary frequency control in island systems composed of multiple Virtual Synchronous Generators (VSGs). It begins by analyzing the shift from traditional synchronous generators to VSGs, driven by the increasing adoption of new energy sources. The text then introduces three secondary frequency control methods: the translation method, the rotation method, and the combined adjustment method. Each method is explained in detail, highlighting their advantages and limitations. The translation method focuses on adjusting the power set point to translate the P-f characteristic curve, while the rotation method changes the damping coefficient to rotate the curve around the rated operating point. The combined adjustment method integrates both approaches to improve frequency regulation flexibility. The chapter also includes comprehensive simulations to validate the proposed methods, demonstrating their effectiveness in maintaining system frequency within safe limits. The conclusion summarizes the benefits of the joint adjustment algorithm in enhancing the stability and safety of multi-VSG island systems, providing a valuable contribution to the field of power system control and renewable energy integration.