Research on Fault Calculation Methods for Relay Protection Setting Calculation in AC Power Grids Containing New Energy Sources
The impedance matrix-based fault calculation method has been widely used in measuring relay protection for AC networks due to its small calculation size and applicability to local solutions.The widespread access to new energy sources has changed the local character of fault calculation,increasing the memory required for fault calculation and reducing the efficiency of fault calculation.This paper proposes a fault calculation method based on the formula for new energy sources and the influence of new energy sources on the fault nodes.This applies to the fault calculation of relay protection in AC networks with new energy sources.Firstly,the initial calculation domain is constructed by screening the new energy sources with strong influence on the fault electrical quantities from the network structure;secondly,the initial calculation domain is further supplemented and modified from the new energy output;finally,the final calculation domain is formed by layer-by-layer expansion.While ensuring the calculation accuracy required by the project,the usage rate of matrix elements is reduced,the calculation volume of fault calculation is reduced,and the calculation efficiency is improved.The accuracy and computational efficiency of the method were verified in the IEEE39 node and IEEE118 node systems.
万方数据
维普
