基于奇异值分析的构网型变流器并联系统小干扰稳定裕度量化与振荡风险评估OA

Grid-forming(GFM)converters can provide voltage and frequency support for power systems.However,the parallel systems of GFM converters still face a high risk of oscillations.It is difficult for traditional stability indicators to accurately and quickly quantify the stability margin for certain non-minimum-phase systems to assess oscillation risks.To address this issue,this paper presents a stability-margin indicator based on singular value theory for analyzing the stability of parallel systems.Firstly,a small-signal model is established for a single GFM converter on the joint power-voltage control timescale.This model can describe the dynamic characteristics of the phase and magnitude of the internal voltage under active and reactive power excitation from the voltage-source perspective.Subsequently,a standard feedback model for a parallel system of GFM converters is constructed,and a generalized method for calculating the robust stability margin is proposed.Finally,the influence of control parameters on the stability margin is analyzed.Simulations verify the correctness of the proposed indicator,and comparative experiments show that it is more accurate and more widely applicable than traditional stability indicators.The singular value-based stability margin can accurately assess the oscillation risks in parallel systems of GFM converters,thereby providing a theoretical basis for equipment parameter design.