Research On Method Of Limiting Short-circuit Currents And Partition Principle For UHV Interconnected Power System

Voltage electromagnetic ring operating of1000kV/500kV/220kV makes a short-circuit current exceed of500kV substations around UHV substation after UHV power grid interconnection of the "SANHUA", which needs effective current limiting measures to reduce short-circuit current to ensure the safe and stable operation of the power system. Research on UHV power grid circuit current control measures and hierarchical partitioning methods has a significant meaning to continue to build the power grid, and have a good effect for planning the future grid.This thesis mainly from the perspective of reducing system short circuit current study of UHV power transmission network, in UHV transmission characteristics as a research starting point, the synthesis of various current limiting measures and grid partition as a way to solve the problem. Start with "SANHUA" power grid of north China power grid as an example to study the UHV network, short-circuit current level of500kV UHV substation site of the impact of; Second of all kinds of current limiting measures in the applicability of the UHV transmission are studied, from the commonly used means of limiting short circuit current to find suitable for UHV current limiting measures; Then grid partition model is established, and based on this model, respectively, from the security, stability, economy, rationality, independent, containing the UHV transmission line network partition principle and concrete implementation method and the calculation process, with Beijing power grid as an example to the validation; Finally in view of the north China power grid, considering current limiting effect, safety, stability, economic factors, such as combination of1000kV substation and its surrounding the distribution of the short circuit current, integrated application of a variety of current limiting measures, design of a current limit and optimization scheme, and the simulation to verify the rationality of the scheme.UHV network take effective suitable for UHV transmission technology of grid current limiting measures and the principle of matching partition can very good reduce system short circuit current. Research has important theoretical and practical value.