基于相量与拓扑同调方法的跟网型与构网型电压源变换器一致性与差异性动态分析

Grid-following voltage source converter(GFL-VSC)and grid-forming voltage source converter(GFM-VSC)have different dynamic characteristics for active power-frequen-cy and reactive power-voltage supports of the power grid.This paper aims to clarify and recognize the difference between grid-following(GFL)and grid-forming(GFM)frequency-voltage support more intuitively and clearly.Firstly,the phasor model considering circuit constraints is established based on the port circuit equations of the converter.It is revealed that the voltage and active power linearly correspond to the horizontal and ver-tical axes in the phasor space referenced to the grid voltage pha-sor.Secondly,based on topological homology,GFL and GFM controls are transformed and mapped into different trajecto-ries.The topological similarity of the characteristic curves for GFL and GFM controls is the essential cause of their uniformi-ty.Based on the above model,it is indicated that GFL-VSC and GFM-VSC possess uniformity with regard to active power re-sponse,type of coupling,and phasor trajectory.They differ in synchronization,power coupling mechanisms,dynamics,and ac-tive power-voltage operation domain in the quasi-steady state.Case studies are undertaken on GFL-VSC and GFM-VSC inte-grated into a four-machine two-area system.Simulation results verify that the dynamic uniformity and difference of GFL-VSC and GFM-VSC are intuitively and comprehensively revealed.