Research On Wide-area Control And Backup Protection Based On Intelligent Substation

With the large-scale interconnection of power grids,the safety and stability of power systems become more and more prominent.The wide-area control and backup protection system uses the multi-point information obtained by the communication network,makes full use of the information redundancy,improves the selectivity,the sensitivity and the reliability of the protection system,and can realize the global optimal coordination control,and effectively guarantees the safety and stability operation of the power grid.It is one of the promising development direction of relay protection.That the development and maturity of intelligent substation technology provides an opportunity to fundamentally improve and improve the performance of traditional relay protection.The ultimate goal of the development of wide-area control and backup protection is to eliminate large-scale blackouts and achieve global optimal control,but the purpose of this stage is to optimize the principle of reserve protection and improve the reliability of system power supply.Information sharing,free distribution,scalability and other characteristics of the intelligent substation,can better improve the existing principle of backup protection algorithm:(1)using the information to the side to reduce the trip-time,optimize the backup protection features;(2)for the double lines on the same pole,when the main protection fails,the backup protection may consider increasing the two-lane successive fast-trip logic;(3)that the application of IEC61850 and IEC61588 protocol on the network-time check,makes wide-area differential current differential protection possible to provide adjacent areas with small delay,selective differential backup protection.In the intelligent substation,the wide-area control and backup protection can use the information of the whole station and the adjacent substation at the same time to replace the main protection of the line when the main protection fails to trip;The wide-area control and backup protection can simplify the setting calculation with the whole station information;Through the interface and the dispatch center,the wide-area control and backup protection can automatically set the settings and adjust the value online according to the change of the operation mode.By discussing the feasibility and specific implementation of wide-area control and backup protection,this paper suggests to reserve wide area control and backup protection interface in Li'zhou to realize the regional backup protection and coordination control through interaction.In the near stage,after the formation of a certain size of the substation,it is necessary to put the signal into trial operation(no trip)to verify the reliability and practicality of the wide-area control and backup protection,so as to gain the experience of the implementation of wide-area control and backup protection,and provide reference of the development of intelligent substation.