Study On The Cyber Security And Its Prevention Of Protection Relay In Digital Substation Including Remote Operation

With the accelerated pace of China's economic construction,the size of the power grid is also increasing exponentially.The rapid increase of the scale of power grid will inevitably bring about the frequent adjustment of the power grid operation mode,and the workload of relay protection device is increasing rapidly.In this situation,the traditional mode of field operation of relay protection must be replaced by a more advanced and intelligent way to adapt to the development of smart grid and digital substation.In the face of the great pressure of relay protection field operation,the remote operation of relay protection has become an inevitable development trend.This will greatly reduce the working pressure of substation operating personnel,improving the efficiency of the transformer substation and the degree of automation.However,once the relay protection realizes the remote operation,it will inevitably cause all the important information of relay protection device to be exposed to the communication network.At the same time,power grid accidents occur frequently because of cyber attacks in recent years,so by the cyber security worries,the remote operation of relay protection is not widespread.Facing the above urgent need to solve the engineering problems,The first of all,this paper describes the content of remote operation of relay protection,and analyzes those cyber security problems that is facing realization of remote operation of relay protection,and put forward the corresponding protection strategy.The second,all the business operation orders involving operational mode changes and operating maintenance arising from an external substation or aninternal one should follow a strict closed-loop business control with high cyber security guarantee.A closed-loop business supervising and control mechanism,starting from the an unified remote operation-order-sheet making and order transferring from the dispatch control center,ending at the unique executing by a novel secure operation module for protective relay(SOMR)in substation,and The process of operation-order-sheet,as well as process of closed-loop business control is designed in detail.In order to prevent the destruction of a substation layer process the raw data,this paper presented a novel scheme of cyber-attack detection and evidence taking for substation process layer and SMV secure transmission.In the substation building sampled measured values attack detection and evidence taking(SVDE),multi detection algorithm is designed based on the engineering practice.At last,the OPENT network simulation software is used to simulate the real-time performance of the SVDE module.This research about the cyber security and its prevention of protection relay in digital substation including remote operation is great significance for realization of remote operation of relay protection and the construction of the digital substation.