虚拟调速器对VSG暂态功角稳定影响机理分析

Impact mechanism analysis of virtual governor on transient power angle stability of VSG

作为重要的一次调频环节,虚拟调速器(VG)对于大扰动下虚拟同步发电机(VSG)保持暂态功角稳定非常重要。以低通滤波(LPF)和高通滤波(HPF)型VG为研究对象,分别构建相应的VSG暂态大信号模型,采用扩展等面积定则分析考虑不同调速器时的VSG暂态功角稳定机理,并利用相图法量化研究VG控制参数对VSG暂态功角稳定的影响。研究发现,VG截止频率的减小会提高系统暂态功角稳定,LPF型VG增益的增加会增强系统暂态功角稳定,而HPF型VG增益的增加会造成系统暂态功角稳定先增强后减弱,且当VG的增益和截止频率相同时,LPF型VG比HPF型VG具有更大的系统暂态功角稳定裕度。仿真结果验证了理论分析的正确性。

As an important part of primary frequency regulation,VG(Virtual Governor)is extremely important for VSG(Virtual Synchronous Generator)to maintain transient power angle stability under large disturbances.The LPF(Low-Pass Filter)and HPF(High-Pass Filter)type VGs are taken for research objects,the corresponding VSG transient large signal models are built.The extended equal area criterion is adopted to analyze VSG transient power angle stability mechanism considering different governors,and the phase portrait method is used to quantitatively research the impact of VG control parameters on VSG transient power angle stability.It is found that decreasing the cut-off frequency of VG will improve the system transient power angle stability,increasing the gain of LPF type VG will strengthen the system transient power angle stability,while increasing the gain of HPF type VG will cause the system transient power angle stability strengthen first and then weaken.When the gain and cut-off frequency of VG are the same,LPF type VG has a larger margin of system transient power angle stability than that of HPF type VG.The correctness of theoretical analysis is verified by the simulative results.