阻抗模裕度指标在新能源多馈入系统静态电压稳定评估的适应性分析OA北大核心CSTPCD

Most centralized renewable energy stations(RES)are located at the end of the power grid.With the increase of active power generation,static voltage instability problem may occur.In this paper,the application object of the traditional impedance modulus index is extended from the load to the RES,which enriches the applicability scenarios of this index for static voltage stability evaluation,including the renewable energy system with reactive power compensation,the renewable energy cluster feeding system,and the renewable energy multi-machine multi-infeed system.Specifically,the critical static voltage stability conditions of the new energy in the single-machine single-infeed system(SMSIS)are analyzed,and based on this,the impedance mode margin index and stability criterion to evaluate the voltage stability of RES are given.Then,by merging the compensation equipment into the system impedance,the influence of reactive power compensation on the index is analyzed.Furthermore,it is proved that in the renewable energy cluster feeding system,voltage instability at the point of common coupling(PCC)will occur before a single RES;thus,the PCC is determined as the calculation node of the index.After that,in order to consider the impact between different RES in the multi-machine multi-infeed system(MMMIS),in the calculation process of the index,the RES to be evaluated are reserved.The other RES are equivalent to negative impedance to be merged into the node impedance matrix,which realizes the extended application in MMMIS.Finally,based on the MMMIS and actual large power grid system established in PSD-BPA,the validity of the index is verified and compared with the existing methods.