Reliability Research Of Intelligent Substation Based On Redundancy Design

With the increasingly serious problems of the energy shortage and environment pollution,the concept of smart grid has been widely recognized and rapidly developed.In order to promote the construction process of smart grid,as an important network node,the development of smart substation has important practical significance.Compared with traditional substation,smart substation has more advantages in automation,intelligence and digitization.However,due to the improvement of intelligent demands,the data flow information increases sharply,which puts higher requirements on the reliability of communication in intelligent substation.Currently,there are many reliable operation methods for intelligent substations based on simplified and intelligent control.When these methods do not further improve system reliability,redundant design will become the only method.This paper studies the redundancy scheme of communication service in intelligent substation,and tries to further improve the reliability through the redundancy design of GOOSE(Generic Object Oriented Substation Events)service and SMV(Sampled Measured Value)service.Firstly,in order to investigate the feasibility of redundant design in the reliability improvement of intelligent substation,based on the reliability evaluation methods of secondary equipment,the working life before and after the redundancy scheme in the series and parallel structure is compared and analyzed.This verifies the role of redundant design in reliability improvement.Then,by analyzing the current protection equipment,it is found that the current redundancy scheme only applies part of the link resources,which makes it feasible to improve the reliability of the substation based on the redundant design.Secondly,to realize the redundant design of SMV,aiming at sampling data synchronization,the causes of out-of-synchronization and pseudo-synchronization problems are analyzed,and a redundant design scheme of SMV sampling synchronization problem based on data preservation and interpolation calculation is proposed.The principle of quality protection is also given.Then,to realize the redundant design of GOOSE,based on the communication realization process,the mechanism of sending,receiving and fault handling is designed.Based on this,the redundancy design scheme of process layer GOOSE communication and SMV co-network transmission is studied.For GOOSE communication in process layer,it can be realized only based on the double network data redundancy.For the common network transmission,focusing on the most prominent blocking problem,a non-blocking redundancy scheme based on virtual time scale is proposed.Finally,in order to verify the effectiveness of the redundant design scheme,a test platform was built on the basis of the PCS915 bus protection machine.In the direct-network acquisition and common-network transmission scenarios,the synchronization quality of the merged unit data is tested.The results show that under the designed SMV and GOOSE redundancy scheme,the protection does not cause blocking problem in the whole process of point-to-point fiber breaking and recovery,so that the bus protection can operate normally without being affected by link anomalies.This improves the reliability of smart substation operation.