Research On Improvement Of 220kV Busbar Protection

Busbars are the important components of power plants and substations.With the rapid development of power grids,the requirements for busbar protection are also increasing in order to ensure the safe and stable operation of power grids.Although great achievements have been made in microcomputer busbar protection,due to the differences in the busbar wiring modes,the design flaws of the busbar protection itself,and the complexity of the actual operation and operation of the busbar protection by the on-site worker,it still causes security risks to the operation of substation busbars.This study aims at the existing problems of busbar protection,analyzes and designs corresponding solutions for busbar protection self-adaptation,failure protection main transformer solution for decompression and blocking,current transformer saturation and so on.In this study,the improvement of 220 kV microcomputer busbar protection is realized based on the double busbar protection reconstruction project carried out in Cao Tun 220 kV Substation in Dalian Development Zone.This study first describes the ability of busbar protection to have the four basic properties of protective relaying to meet the needs of the power system,and describes the evolution of busbar protection.With the continuous development of science and technology,busbar protection has gradually matured.Then the study briefly describes the current situation and problems of busbar protection in Caotun 220 kV substation in Dalian Development Zone.Next,the principle of differential protection in busbar protection,the principle of circuit breaker failure protection and the principle of current transformer saturation are analyzed,which lays a theoretical foundation for the improvement of existing busbar protection.The problem of double busbar protection reconstruction for the Caotun 220 kV substation in Dalian Development and the related research and design are completed.In allusion to the lack of self-adaptive ability of the busbar differential protection to the busbar operation mode,the causes of the busbar protection are analyzed and put forward the corresponding hardware solutions and software solutions to the impact of busbar protection.Aiming at the design defect of the main transformer solution for recomptrssion and blocking in the circuit breaker's failure protection,the function and action logic of the circuit breaker's failure protection are analyzed,and the corrective measures are put forward;According to the influence of current transformer saturation on busbar protection,combine with the causes and characteristics of current transformer saturation,theoretical analysis and logical judgment are made.Various schemes for preventing the influence of saturation on the busbar protection are implemented so that the busbar protection can still operate correctly even if the phenomenon of saturation of the current transformer occurs or in the event of a fault,to ensure the safe and stable operation of the grid.Finally,the improved scheme of bus protection is modeled by MATLAB and RTDS.Through the analysis of the experimental data and results,the feasibility of the proposed scheme is verified and the purpose of improving the busbar protection of 220 kV is achieved.It provides a useful reference for the research of 220 kV busbar protection.