Control strategy of grid-forming converter based on passivity-based control
NIE Yonghui
LI Zhongyang
Abstract：[Objective]Under the impetus of the carbon peaking and carbon neutrality goals,the high proportion of renewable energy grid connection has weakened system inertia and damping characteristics,posing a serious threat to grid stability.Although grid-forming virtual synchronous generator(VSG)control technology can actively provide inertia support for the grid,the complex nonlinear characteristics of renewable energy systems cause traditional VSG control to face risks of instability in angular frequency and output voltage under non-ideal operating conditions,resulting in suboptimal control performance.To address this issue,this paper proposed a grid-forming converter control strategy based on passivity-based control,overcoming the limitations of traditional linear control methods to enhance system dynamic response performance,interference resistance,and robustness.[Methods]This paper adopted a nonlinear control design framework.According to VSG control principles,the rotor motion equation of a synchronous generator was employed to achieve active frequency regulation,and the excitation system was used to achieve reactive voltage control.A Hamilton system model incorporating grid-forming control was built.Based on the core principles of passivity-based control theory,the Hamilton model was mathematically transformed into a dissipative Hamilton standard form with port characteristics.This model inherently possesses advantages for stability analysis,providing a theoretical foundation for controller design.In addition,based on the system's stable operation requirements,the desired equilibrium operating point was set.To accelerate the dissipation of system energy toward the desired equilibrium point,effectively suppress oscillations,and enhance convergence speed,a damping term was introduced.Ultimately,the active and reactive control laws applicable to grid-forming converters were derived,achieving global asymptotic stability of the nonlinear system.[Results]Simulation test results show that under non-ideal conditions such as power change,grid voltage imbalance,short-circuit fault,and load variation,the grid-forming converter control strategy based on passivity-based control significantly outperforms traditional VSG control in terms of system angular frequency stability.The amplitude of frequency fluctuations is significantly reduced,and the time required to recover to the desired value is greatly shortened.The overshoot of the output voltage is reduced,the regulation process is smoother,and the voltage stabilizes faster,effectively enhancing voltage stability.[Conclusions]The proposed grid-forming converter stability control strategy establishes a nonlinear design framework based on the dissipative Hamilton model and designs a control strategy through energy shaping and damping injection.The derived control laws exhibit strong robustness and can accommodate complex operating conditions without requiring a precise system model.It effectively addresses the stability deficiencies and slow dynamic response of traditional VSG control when faced with system nonlinearities,overcoming the limitations of fixed linear control parameters.This provides a control strategy with strong interference resistance and fast dynamic response for renewable energy grid-connected systems,supporting the stable operation of new power systems.
Keywords：non-ideal conditiongrid-forming controlvirtual synchronous controlpassivity-based controlHamiltonian modelconvertersystem stabilitycontrol strategy
Publication Date：2026-01-25
Online Publishing Date：2026-03-17(First online date of this platform, not the publication date of the document)
Pages：9( 1-9 )