Review of grid-forming control technology for new energy in frequency modulation
LI Weixing
PAN Yuntong
MA Xintong
CHAO Pupu
SUN Guangyu
JIN Yonglin
Abstract：[Objective]With the increasing proportion of new energy,traditional grid-following(GFL)control based on phase-locked loop(PLL)synchronization gradually exhibits inherent stability limitations in weak grid conditions.Meanwhile,grid-forming(GFM)control with self-synchronizing source characteristics has emerged as a hot solution.However,existing research predominantly focuses on the voltage regulation or synchronization stability of GFM control,with less attention to its frequency modulation capability and characteristics.[Methods]This paper systematically reviewed four mainstream GFM control methods,including droop control,virtual synchronous generator(VSG)control,matching control,and virtual oscillator control(VOC),explained their frequency modulation principles,and analyzed their advantages and disadvantages from the aspects of the control loop and application scenarios.On this basis,a grid-connected simulation model for new energy systems was built to conduct a simulation-based analysis of the frequency modulation response characteristics of different kinds of frequency modulation control across diverse scenarios.Finally,this study summarized challenges of GFM control in strategy optimization,parameter tuning,and multi-unit coordination,with the future development prospects pointed out.[Results]Droop control regulates the active power of generating units by responding to system frequency deviations,featuring advantages of the simple structure and strong grid strength adaptability.However,its lack of inertia support results in relatively weaker frequency modulation performance.On the basis of droop control,VSG control simulates the inertia response characteristics of conventional synchronous machines and can better suppress the change performance of system frequency.However,it faces challenges in parameter tuning,fault ride-through,and multi-unit coordination.Matching control utilizes the dynamic characteristics of DC capacitors to simulate the inertia properties of traditional synchronous machines and thus restrain change performance of system frequency,but it fails to provide sustained support in the frequency quasi-steady state.VOC generates frequency responses similar to droop control via oscillator dynamic equations that directly govern amplitude and frequency.However,it is difficult for its high output harmonics to satisfy grid connection requirements.[Conclusion]Virtual synchronous machine control has become the most promising research direction in GFM control due to its technical advantages of balancing frequency modulation performance and strong grid strength adaptability in participating in system frequency modulation.However,technical challenges including synchronization stability,fault ride-through,and coordinated control need to be tackled.In the future,in-depth research should be conducted on control strategies and parameter optimization,and multi-unit collaborated control to facilitate the large-scale application of GFM control.
Keywords：new energygrid-formingfrequency modulation controldroop controlvirtual synchronous generator controlmatching controlvirtual oscillator control
Publication Date：2025-09-25
Online Publishing Date：2025-10-31(First online date of this platform, not the publication date of the document)
Pages：13( 545-557 )