基于实时生成定值的高比例新能源电网自适应电流保护OACSTPCD

The power sides of new power systems contain a large proportion of new energy sources.Owing to various types,distributed locations,and nonlinear outputs,the through-current level of the short circuit decreases,and its uncertainty increases when a fault occurs in the power grid,which makes it difficult for traditional current protection to preset and trip.Therefore,an adaptive current protection method based on real-time generated settings using local information is proposed,referring to traditional three-stage current protection.This method considers the actual fault characteristics of new energy sources to generate a preset.First,an equivalent source model is established that can distinguish the different outputs of new energy sources between generators and identify them online to obtain the unchanged parameters before and after the fault.Then,after a fault occurs,the local measured information is used to obtain the changeable parameters.Subsequently,preset values were generated in real-time based on the actual fault scenario and the actual output of new energy sources during the fault.Finally,the trip is decided based on the measured current and the preset value.Continuous identification before a fault occurs can effectively separate generators and new energy sources in the model.Online presetting based on actual fault scenarios and the output of new energy sources can effectively solve the problems of variety,distribution,and nonlinearity.The feasibility and correctness were verified by both analysis and comparison of various cases.